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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/ceph/ceph_debug.h>
 
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/highmem.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #ifdef CONFIG_BLOCK
 #include <linux/bio.h>
 #endif
 
 #include <linux/ceph/ceph_features.h>
 #include <linux/ceph/libceph.h>
 #include <linux/ceph/osd_client.h>
 #include <linux/ceph/messenger.h>
 #include <linux/ceph/decode.h>
 #include <linux/ceph/auth.h>
 #include <linux/ceph/pagelist.h>
 #include <linux/ceph/striper.h>
 
 #define OSD_OPREPLY_FRONT_LEN   512
 
 static struct kmem_cache    *ceph_osd_request_cache;
 
 static const struct ceph_connection_operations osd_con_ops;
 
 /*
  * Implement client access to distributed object storage cluster.
  *
  * All data objects are stored within a cluster/cloud of OSDs, or
  * "object storage devices."  (Note that Ceph OSDs have _nothing_ to
  * do with the T10 OSD extensions to SCSI.)  Ceph OSDs are simply
  * remote daemons serving up and coordinating consistent and safe
  * access to storage.
  *
  * Cluster membership and the mapping of data objects onto storage devices
  * are described by the osd map.
  *
  * We keep track of pending OSD requests (read, write), resubmit
  * requests to different OSDs when the cluster topology/data layout
  * change, or retry the affected requests when the communications
  * channel with an OSD is reset.
  */
 
 static void link_request(struct ceph_osd *osd, struct ceph_osd_request *req);
 static void unlink_request(struct ceph_osd *osd, struct ceph_osd_request *req);
 static void link_linger(struct ceph_osd *osd,
             struct ceph_osd_linger_request *lreq);
 static void unlink_linger(struct ceph_osd *osd,
               struct ceph_osd_linger_request *lreq);
 static void clear_backoffs(struct ceph_osd *osd);
 
 #if 1
 static inline bool rwsem_is_wrlocked(struct rw_semaphore *sem)
 {
     bool wrlocked = true;
 
     if (unlikely(down_read_trylock(sem))) {
         wrlocked = false;
         up_read(sem);
     }
 
     return wrlocked;
 }
 static inline void verify_osdc_locked(struct ceph_osd_client *osdc)
 {
     WARN_ON(!rwsem_is_locked(&osdc->lock));
 }
 static inline void verify_osdc_wrlocked(struct ceph_osd_client *osdc)
 {
     WARN_ON(!rwsem_is_wrlocked(&osdc->lock));
 }
 static inline void verify_osd_locked(struct ceph_osd *osd)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
 
     WARN_ON(!(mutex_is_locked(&osd->lock) &&
           rwsem_is_locked(&osdc->lock)) &&
         !rwsem_is_wrlocked(&osdc->lock));
 }
 static inline void verify_lreq_locked(struct ceph_osd_linger_request *lreq)
 {
     WARN_ON(!mutex_is_locked(&lreq->lock));
 }
 #else
 static inline void verify_osdc_locked(struct ceph_osd_client *osdc) { }
 static inline void verify_osdc_wrlocked(struct ceph_osd_client *osdc) { }
 static inline void verify_osd_locked(struct ceph_osd *osd) { }
 static inline void verify_lreq_locked(struct ceph_osd_linger_request *lreq) { }
 #endif
 
 /*
  * calculate the mapping of a file extent onto an object, and fill out the
  * request accordingly.  shorten extent as necessary if it crosses an
  * object boundary.
  *
  * fill osd op in request message.
  */
 static int calc_layout(struct ceph_file_layout *layout, u64 off, u64 *plen,
             u64 *objnum, u64 *objoff, u64 *objlen)
 {
     u64 orig_len = *plen;
     u32 xlen;
 
     /* object extent? */
     ceph_calc_file_object_mapping(layout, off, orig_len, objnum,
                       objoff, &xlen);
     *objlen = xlen;
     if (*objlen < orig_len) {
         *plen = *objlen;
         dout(" skipping last %llu, final file extent %llu~%llu\n",
              orig_len - *plen, off, *plen);
     }
 
     dout("calc_layout objnum=%llx %llu~%llu\n", *objnum, *objoff, *objlen);
     return 0;
 }
 
 static void ceph_osd_data_init(struct ceph_osd_data *osd_data)
 {
     memset(osd_data, 0, sizeof (*osd_data));
     osd_data->type = CEPH_OSD_DATA_TYPE_NONE;
 }
 
 /*
  * Consumes @pages if @own_pages is true.
  */
 static void ceph_osd_data_pages_init(struct ceph_osd_data *osd_data,
             struct page **pages, u64 length, u32 alignment,
             bool pages_from_pool, bool own_pages)
 {
     osd_data->type = CEPH_OSD_DATA_TYPE_PAGES;
     osd_data->pages = pages;
     osd_data->length = length;
     osd_data->alignment = alignment;
     osd_data->pages_from_pool = pages_from_pool;
     osd_data->own_pages = own_pages;
 }
 
 /*
  * Consumes a ref on @pagelist.
  */
 static void ceph_osd_data_pagelist_init(struct ceph_osd_data *osd_data,
             struct ceph_pagelist *pagelist)
 {
     osd_data->type = CEPH_OSD_DATA_TYPE_PAGELIST;
     osd_data->pagelist = pagelist;
 }
 
 #ifdef CONFIG_BLOCK
 static void ceph_osd_data_bio_init(struct ceph_osd_data *osd_data,
                    struct ceph_bio_iter *bio_pos,
                    u32 bio_length)
 {
     osd_data->type = CEPH_OSD_DATA_TYPE_BIO;
     osd_data->bio_pos = *bio_pos;
     osd_data->bio_length = bio_length;
 }
 #endif /* CONFIG_BLOCK */
 
 static void ceph_osd_data_bvecs_init(struct ceph_osd_data *osd_data,
                      struct ceph_bvec_iter *bvec_pos,
                      u32 num_bvecs)
 {
     osd_data->type = CEPH_OSD_DATA_TYPE_BVECS;
     osd_data->bvec_pos = *bvec_pos;
     osd_data->num_bvecs = num_bvecs;
 }
 
 static struct ceph_osd_data *
 osd_req_op_raw_data_in(struct ceph_osd_request *osd_req, unsigned int which)
 {
     BUG_ON(which >= osd_req->r_num_ops);
 
     return &osd_req->r_ops[which].raw_data_in;
 }
 
 struct ceph_osd_data *
 osd_req_op_extent_osd_data(struct ceph_osd_request *osd_req,
             unsigned int which)
 {
     return osd_req_op_data(osd_req, which, extent, osd_data);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data);
 
 void osd_req_op_raw_data_in_pages(struct ceph_osd_request *osd_req,
             unsigned int which, struct page **pages,
             u64 length, u32 alignment,
             bool pages_from_pool, bool own_pages)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_raw_data_in(osd_req, which);
     ceph_osd_data_pages_init(osd_data, pages, length, alignment,
                 pages_from_pool, own_pages);
 }
 EXPORT_SYMBOL(osd_req_op_raw_data_in_pages);
 
 void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *osd_req,
             unsigned int which, struct page **pages,
             u64 length, u32 alignment,
             bool pages_from_pool, bool own_pages)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
     ceph_osd_data_pages_init(osd_data, pages, length, alignment,
                 pages_from_pool, own_pages);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_pages);
 
 void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *osd_req,
             unsigned int which, struct ceph_pagelist *pagelist)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
     ceph_osd_data_pagelist_init(osd_data, pagelist);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_pagelist);
 
 #ifdef CONFIG_BLOCK
 void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
                     unsigned int which,
                     struct ceph_bio_iter *bio_pos,
                     u32 bio_length)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
     ceph_osd_data_bio_init(osd_data, bio_pos, bio_length);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_bio);
 #endif /* CONFIG_BLOCK */
 
 void osd_req_op_extent_osd_data_bvecs(struct ceph_osd_request *osd_req,
                       unsigned int which,
                       struct bio_vec *bvecs, u32 num_bvecs,
                       u32 bytes)
 {
     struct ceph_osd_data *osd_data;
     struct ceph_bvec_iter it = {
         .bvecs = bvecs,
         .iter = { .bi_size = bytes },
     };
 
     osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
     ceph_osd_data_bvecs_init(osd_data, &it, num_bvecs);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_bvecs);
 
 void osd_req_op_extent_osd_data_bvec_pos(struct ceph_osd_request *osd_req,
                      unsigned int which,
                      struct ceph_bvec_iter *bvec_pos)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
     ceph_osd_data_bvecs_init(osd_data, bvec_pos, 0);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_bvec_pos);
 
 static void osd_req_op_cls_request_info_pagelist(
             struct ceph_osd_request *osd_req,
             unsigned int which, struct ceph_pagelist *pagelist)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, cls, request_info);
     ceph_osd_data_pagelist_init(osd_data, pagelist);
 }
 
 void osd_req_op_cls_request_data_pagelist(
             struct ceph_osd_request *osd_req,
             unsigned int which, struct ceph_pagelist *pagelist)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, cls, request_data);
     ceph_osd_data_pagelist_init(osd_data, pagelist);
     osd_req->r_ops[which].cls.indata_len += pagelist->length;
     osd_req->r_ops[which].indata_len += pagelist->length;
 }
 EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
 
 void osd_req_op_cls_request_data_pages(struct ceph_osd_request *osd_req,
             unsigned int which, struct page **pages, u64 length,
             u32 alignment, bool pages_from_pool, bool own_pages)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, cls, request_data);
     ceph_osd_data_pages_init(osd_data, pages, length, alignment,
                 pages_from_pool, own_pages);
     osd_req->r_ops[which].cls.indata_len += length;
     osd_req->r_ops[which].indata_len += length;
 }
 EXPORT_SYMBOL(osd_req_op_cls_request_data_pages);
 
 void osd_req_op_cls_request_data_bvecs(struct ceph_osd_request *osd_req,
                        unsigned int which,
                        struct bio_vec *bvecs, u32 num_bvecs,
                        u32 bytes)
 {
     struct ceph_osd_data *osd_data;
     struct ceph_bvec_iter it = {
         .bvecs = bvecs,
         .iter = { .bi_size = bytes },
     };
 
     osd_data = osd_req_op_data(osd_req, which, cls, request_data);
     ceph_osd_data_bvecs_init(osd_data, &it, num_bvecs);
     osd_req->r_ops[which].cls.indata_len += bytes;
     osd_req->r_ops[which].indata_len += bytes;
 }
 EXPORT_SYMBOL(osd_req_op_cls_request_data_bvecs);
 
 void osd_req_op_cls_response_data_pages(struct ceph_osd_request *osd_req,
             unsigned int which, struct page **pages, u64 length,
             u32 alignment, bool pages_from_pool, bool own_pages)
 {
     struct ceph_osd_data *osd_data;
 
     osd_data = osd_req_op_data(osd_req, which, cls, response_data);
     ceph_osd_data_pages_init(osd_data, pages, length, alignment,
                 pages_from_pool, own_pages);
 }
 EXPORT_SYMBOL(osd_req_op_cls_response_data_pages);
 
 static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
 {
     switch (osd_data->type) {
     case CEPH_OSD_DATA_TYPE_NONE:
         return 0;
     case CEPH_OSD_DATA_TYPE_PAGES:
         return osd_data->length;
     case CEPH_OSD_DATA_TYPE_PAGELIST:
         return (u64)osd_data->pagelist->length;
 #ifdef CONFIG_BLOCK
     case CEPH_OSD_DATA_TYPE_BIO:
         return (u64)osd_data->bio_length;
 #endif /* CONFIG_BLOCK */
     case CEPH_OSD_DATA_TYPE_BVECS:
         return osd_data->bvec_pos.iter.bi_size;
     default:
         WARN(true, "unrecognized data type %d\n", (int)osd_data->type);
         return 0;
     }
 }
 
 static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
 {
     if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES && osd_data->own_pages) {
         int num_pages;
 
         num_pages = calc_pages_for((u64)osd_data->alignment,
                         (u64)osd_data->length);
         ceph_release_page_vector(osd_data->pages, num_pages);
     } else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
         ceph_pagelist_release(osd_data->pagelist);
     }
     ceph_osd_data_init(osd_data);
 }
 
 static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
             unsigned int which)
 {
     struct ceph_osd_req_op *op;
 
     BUG_ON(which >= osd_req->r_num_ops);
     op = &osd_req->r_ops[which];
 
     switch (op->op) {
     case CEPH_OSD_OP_READ:
     case CEPH_OSD_OP_WRITE:
     case CEPH_OSD_OP_WRITEFULL:
         ceph_osd_data_release(&op->extent.osd_data);
         break;
     case CEPH_OSD_OP_CALL:
         ceph_osd_data_release(&op->cls.request_info);
         ceph_osd_data_release(&op->cls.request_data);
         ceph_osd_data_release(&op->cls.response_data);
         break;
     case CEPH_OSD_OP_SETXATTR:
     case CEPH_OSD_OP_CMPXATTR:
         ceph_osd_data_release(&op->xattr.osd_data);
         break;
     case CEPH_OSD_OP_STAT:
         ceph_osd_data_release(&op->raw_data_in);
         break;
     case CEPH_OSD_OP_NOTIFY_ACK:
         ceph_osd_data_release(&op->notify_ack.request_data);
         break;
     case CEPH_OSD_OP_NOTIFY:
         ceph_osd_data_release(&op->notify.request_data);
         ceph_osd_data_release(&op->notify.response_data);
         break;
     case CEPH_OSD_OP_LIST_WATCHERS:
         ceph_osd_data_release(&op->list_watchers.response_data);
         break;
     case CEPH_OSD_OP_COPY_FROM2:
         ceph_osd_data_release(&op->copy_from.osd_data);
         break;
     default:
         break;
     }
 }
 
 /*
  * Assumes @t is zero-initialized.
  */
 static void target_init(struct ceph_osd_request_target *t)
 {
     ceph_oid_init(&t->base_oid);
     ceph_oloc_init(&t->base_oloc);
     ceph_oid_init(&t->target_oid);
     ceph_oloc_init(&t->target_oloc);
 
     ceph_osds_init(&t->acting);
     ceph_osds_init(&t->up);
     t->size = -1;
     t->min_size = -1;
 
     t->osd = CEPH_HOMELESS_OSD;
 }
 
 static void target_copy(struct ceph_osd_request_target *dest,
             const struct ceph_osd_request_target *src)
 {
     ceph_oid_copy(&dest->base_oid, &src->base_oid);
     ceph_oloc_copy(&dest->base_oloc, &src->base_oloc);
     ceph_oid_copy(&dest->target_oid, &src->target_oid);
     ceph_oloc_copy(&dest->target_oloc, &src->target_oloc);
 
     dest->pgid = src->pgid; /* struct */
     dest->spgid = src->spgid; /* struct */
     dest->pg_num = src->pg_num;
     dest->pg_num_mask = src->pg_num_mask;
     ceph_osds_copy(&dest->acting, &src->acting);
     ceph_osds_copy(&dest->up, &src->up);
     dest->size = src->size;
     dest->min_size = src->min_size;
     dest->sort_bitwise = src->sort_bitwise;
     dest->recovery_deletes = src->recovery_deletes;
 
     dest->flags = src->flags;
     dest->used_replica = src->used_replica;
     dest->paused = src->paused;
 
     dest->epoch = src->epoch;
     dest->last_force_resend = src->last_force_resend;
 
     dest->osd = src->osd;
 }
 
 static void target_destroy(struct ceph_osd_request_target *t)
 {
     ceph_oid_destroy(&t->base_oid);
     ceph_oloc_destroy(&t->base_oloc);
     ceph_oid_destroy(&t->target_oid);
     ceph_oloc_destroy(&t->target_oloc);
 }
 
 /*
  * requests
  */
 static void request_release_checks(struct ceph_osd_request *req)
 {
     WARN_ON(!RB_EMPTY_NODE(&req->r_node));
     WARN_ON(!RB_EMPTY_NODE(&req->r_mc_node));
     WARN_ON(!list_empty(&req->r_private_item));
     WARN_ON(req->r_osd);
 }
 
 static void ceph_osdc_release_request(struct kref *kref)
 {
     struct ceph_osd_request *req = container_of(kref,
                         struct ceph_osd_request, r_kref);
     unsigned int which;
 
     dout("%s %p (r_request %p r_reply %p)\n", __func__, req,
          req->r_request, req->r_reply);
     request_release_checks(req);
 
     if (req->r_request)
         ceph_msg_put(req->r_request);
     if (req->r_reply)
         ceph_msg_put(req->r_reply);
 
     for (which = 0; which < req->r_num_ops; which++)
         osd_req_op_data_release(req, which);
 
     target_destroy(&req->r_t);
     ceph_put_snap_context(req->r_snapc);
 
     if (req->r_mempool)
         mempool_free(req, req->r_osdc->req_mempool);
     else if (req->r_num_ops <= CEPH_OSD_SLAB_OPS)
         kmem_cache_free(ceph_osd_request_cache, req);
     else
         kfree(req);
 }
 
 void ceph_osdc_get_request(struct ceph_osd_request *req)
 {
     dout("%s %p (was %d)\n", __func__, req,
          kref_read(&req->r_kref));
     kref_get(&req->r_kref);
 }
 EXPORT_SYMBOL(ceph_osdc_get_request);
 
 void ceph_osdc_put_request(struct ceph_osd_request *req)
 {
     if (req) {
         dout("%s %p (was %d)\n", __func__, req,
              kref_read(&req->r_kref));
         kref_put(&req->r_kref, ceph_osdc_release_request);
     }
 }
 EXPORT_SYMBOL(ceph_osdc_put_request);
 
 static void request_init(struct ceph_osd_request *req)
 {
     /* req only, each op is zeroed in osd_req_op_init() */
     memset(req, 0, sizeof(*req));
 
     kref_init(&req->r_kref);
     init_completion(&req->r_completion);
     RB_CLEAR_NODE(&req->r_node);
     RB_CLEAR_NODE(&req->r_mc_node);
     INIT_LIST_HEAD(&req->r_private_item);
 
     target_init(&req->r_t);
 }
 
 struct ceph_osd_request *ceph_osdc_alloc_request(struct ceph_osd_client *osdc,
                            struct ceph_snap_context *snapc,
                            unsigned int num_ops,
                            bool use_mempool,
                            gfp_t gfp_flags)
 {
     struct ceph_osd_request *req;
 
     if (use_mempool) {
         BUG_ON(num_ops > CEPH_OSD_SLAB_OPS);
         req = mempool_alloc(osdc->req_mempool, gfp_flags);
     } else if (num_ops <= CEPH_OSD_SLAB_OPS) {
         req = kmem_cache_alloc(ceph_osd_request_cache, gfp_flags);
     } else {
         BUG_ON(num_ops > CEPH_OSD_MAX_OPS);
         req = kmalloc(struct_size(req, r_ops, num_ops), gfp_flags);
     }
     if (unlikely(!req))
         return NULL;
 
     request_init(req);
     req->r_osdc = osdc;
     req->r_mempool = use_mempool;
     req->r_num_ops = num_ops;
     req->r_snapid = CEPH_NOSNAP;
     req->r_snapc = ceph_get_snap_context(snapc);
 
     dout("%s req %p\n", __func__, req);
     return req;
 }
 EXPORT_SYMBOL(ceph_osdc_alloc_request);
 
 static int ceph_oloc_encoding_size(const struct ceph_object_locator *oloc)
 {
     return 8 + 4 + 4 + 4 + (oloc->pool_ns ? oloc->pool_ns->len : 0);
 }
 
 static int __ceph_osdc_alloc_messages(struct ceph_osd_request *req, gfp_t gfp,
                       int num_request_data_items,
                       int num_reply_data_items)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     struct ceph_msg *msg;
     int msg_size;
 
     WARN_ON(req->r_request || req->r_reply);
     WARN_ON(ceph_oid_empty(&req->r_base_oid));
     WARN_ON(ceph_oloc_empty(&req->r_base_oloc));
 
     /* create request message */
     msg_size = CEPH_ENCODING_START_BLK_LEN +
             CEPH_PGID_ENCODING_LEN + 1; /* spgid */
     msg_size += 4 + 4 + 4; /* hash, osdmap_epoch, flags */
     msg_size += CEPH_ENCODING_START_BLK_LEN +
             sizeof(struct ceph_osd_reqid); /* reqid */
     msg_size += sizeof(struct ceph_blkin_trace_info); /* trace */
     msg_size += 4 + sizeof(struct ceph_timespec); /* client_inc, mtime */
     msg_size += CEPH_ENCODING_START_BLK_LEN +
             ceph_oloc_encoding_size(&req->r_base_oloc); /* oloc */
     msg_size += 4 + req->r_base_oid.name_len; /* oid */
     msg_size += 2 + req->r_num_ops * sizeof(struct ceph_osd_op);
     msg_size += 8; /* snapid */
     msg_size += 8; /* snap_seq */
     msg_size += 4 + 8 * (req->r_snapc ? req->r_snapc->num_snaps : 0);
     msg_size += 4 + 8; /* retry_attempt, features */
 
     if (req->r_mempool)
         msg = ceph_msgpool_get(&osdc->msgpool_op, msg_size,
                        num_request_data_items);
     else
         msg = ceph_msg_new2(CEPH_MSG_OSD_OP, msg_size,
                     num_request_data_items, gfp, true);
     if (!msg)
         return -ENOMEM;
 
     memset(msg->front.iov_base, 0, msg->front.iov_len);
     req->r_request = msg;
 
     /* create reply message */
     msg_size = OSD_OPREPLY_FRONT_LEN;
     msg_size += req->r_base_oid.name_len;
     msg_size += req->r_num_ops * sizeof(struct ceph_osd_op);
 
     if (req->r_mempool)
         msg = ceph_msgpool_get(&osdc->msgpool_op_reply, msg_size,
                        num_reply_data_items);
     else
         msg = ceph_msg_new2(CEPH_MSG_OSD_OPREPLY, msg_size,
                     num_reply_data_items, gfp, true);
     if (!msg)
         return -ENOMEM;
 
     req->r_reply = msg;
 
     return 0;
 }
 
 static bool osd_req_opcode_valid(u16 opcode)
 {
     switch (opcode) {
 #define GENERATE_CASE(op, opcode, str)  case CEPH_OSD_OP_##op: return true;
 __CEPH_FORALL_OSD_OPS(GENERATE_CASE)
 #undef GENERATE_CASE
     default:
         return false;
     }
 }
 
 static void get_num_data_items(struct ceph_osd_request *req,
                    int *num_request_data_items,
                    int *num_reply_data_items)
 {
     struct ceph_osd_req_op *op;
 
     *num_request_data_items = 0;
     *num_reply_data_items = 0;
 
     for (op = req->r_ops; op != &req->r_ops[req->r_num_ops]; op++) {
         switch (op->op) {
         /* request */
         case CEPH_OSD_OP_WRITE:
         case CEPH_OSD_OP_WRITEFULL:
         case CEPH_OSD_OP_SETXATTR:
         case CEPH_OSD_OP_CMPXATTR:
         case CEPH_OSD_OP_NOTIFY_ACK:
         case CEPH_OSD_OP_COPY_FROM2:
             *num_request_data_items += 1;
             break;
 
         /* reply */
         case CEPH_OSD_OP_STAT:
         case CEPH_OSD_OP_READ:
         case CEPH_OSD_OP_LIST_WATCHERS:
             *num_reply_data_items += 1;
             break;
 
         /* both */
         case CEPH_OSD_OP_NOTIFY:
             *num_request_data_items += 1;
             *num_reply_data_items += 1;
             break;
         case CEPH_OSD_OP_CALL:
             *num_request_data_items += 2;
             *num_reply_data_items += 1;
             break;
 
         default:
             WARN_ON(!osd_req_opcode_valid(op->op));
             break;
         }
     }
 }
 
 /*
  * oid, oloc and OSD op opcode(s) must be filled in before this function
  * is called.
  */
 int ceph_osdc_alloc_messages(struct ceph_osd_request *req, gfp_t gfp)
 {
     int num_request_data_items, num_reply_data_items;
 
     get_num_data_items(req, &num_request_data_items, &num_reply_data_items);
     return __ceph_osdc_alloc_messages(req, gfp, num_request_data_items,
                       num_reply_data_items);
 }
 EXPORT_SYMBOL(ceph_osdc_alloc_messages);
 
 /*
  * This is an osd op init function for opcodes that have no data or
  * other information associated with them.  It also serves as a
  * common init routine for all the other init functions, below.
  */
 struct ceph_osd_req_op *
 osd_req_op_init(struct ceph_osd_request *osd_req, unsigned int which,
          u16 opcode, u32 flags)
 {
     struct ceph_osd_req_op *op;
 
     BUG_ON(which >= osd_req->r_num_ops);
     BUG_ON(!osd_req_opcode_valid(opcode));
 
     op = &osd_req->r_ops[which];
     memset(op, 0, sizeof (*op));
     op->op = opcode;
     op->flags = flags;
 
     return op;
 }
 EXPORT_SYMBOL(osd_req_op_init);
 
 void osd_req_op_extent_init(struct ceph_osd_request *osd_req,
                 unsigned int which, u16 opcode,
                 u64 offset, u64 length,
                 u64 truncate_size, u32 truncate_seq)
 {
     struct ceph_osd_req_op *op = osd_req_op_init(osd_req, which,
                              opcode, 0);
     size_t payload_len = 0;
 
     BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
            opcode != CEPH_OSD_OP_WRITEFULL && opcode != CEPH_OSD_OP_ZERO &&
            opcode != CEPH_OSD_OP_TRUNCATE);
 
     op->extent.offset = offset;
     op->extent.length = length;
     op->extent.truncate_size = truncate_size;
     op->extent.truncate_seq = truncate_seq;
     if (opcode == CEPH_OSD_OP_WRITE || opcode == CEPH_OSD_OP_WRITEFULL)
         payload_len += length;
 
     op->indata_len = payload_len;
 }
 EXPORT_SYMBOL(osd_req_op_extent_init);
 
 void osd_req_op_extent_update(struct ceph_osd_request *osd_req,
                 unsigned int which, u64 length)
 {
     struct ceph_osd_req_op *op;
     u64 previous;
 
     BUG_ON(which >= osd_req->r_num_ops);
     op = &osd_req->r_ops[which];
     previous = op->extent.length;
 
     if (length == previous)
         return;     /* Nothing to do */
     BUG_ON(length > previous);
 
     op->extent.length = length;
     if (op->op == CEPH_OSD_OP_WRITE || op->op == CEPH_OSD_OP_WRITEFULL)
         op->indata_len -= previous - length;
 }
 EXPORT_SYMBOL(osd_req_op_extent_update);
 
 void osd_req_op_extent_dup_last(struct ceph_osd_request *osd_req,
                 unsigned int which, u64 offset_inc)
 {
     struct ceph_osd_req_op *op, *prev_op;
 
     BUG_ON(which + 1 >= osd_req->r_num_ops);
 
     prev_op = &osd_req->r_ops[which];
     op = osd_req_op_init(osd_req, which + 1, prev_op->op, prev_op->flags);
     /* dup previous one */
     op->indata_len = prev_op->indata_len;
     op->outdata_len = prev_op->outdata_len;
     op->extent = prev_op->extent;
     /* adjust offset */
     op->extent.offset += offset_inc;
     op->extent.length -= offset_inc;
 
     if (op->op == CEPH_OSD_OP_WRITE || op->op == CEPH_OSD_OP_WRITEFULL)
         op->indata_len -= offset_inc;
 }
 EXPORT_SYMBOL(osd_req_op_extent_dup_last);
 
 int osd_req_op_cls_init(struct ceph_osd_request *osd_req, unsigned int which,
             const char *class, const char *method)
 {
     struct ceph_osd_req_op *op;
     struct ceph_pagelist *pagelist;
     size_t payload_len = 0;
     size_t size;
     int ret;
 
     op = osd_req_op_init(osd_req, which, CEPH_OSD_OP_CALL, 0);
 
     pagelist = ceph_pagelist_alloc(GFP_NOFS);
     if (!pagelist)
         return -ENOMEM;
 
     op->cls.class_name = class;
     size = strlen(class);
     BUG_ON(size > (size_t) U8_MAX);
     op->cls.class_len = size;
     ret = ceph_pagelist_append(pagelist, class, size);
     if (ret)
         goto err_pagelist_free;
     payload_len += size;
 
     op->cls.method_name = method;
     size = strlen(method);
     BUG_ON(size > (size_t) U8_MAX);
     op->cls.method_len = size;
     ret = ceph_pagelist_append(pagelist, method, size);
     if (ret)
         goto err_pagelist_free;
     payload_len += size;
 
     osd_req_op_cls_request_info_pagelist(osd_req, which, pagelist);
     op->indata_len = payload_len;
     return 0;
 
 err_pagelist_free:
     ceph_pagelist_release(pagelist);
     return ret;
 }
 EXPORT_SYMBOL(osd_req_op_cls_init);
 
 int osd_req_op_xattr_init(struct ceph_osd_request *osd_req, unsigned int which,
               u16 opcode, const char *name, const void *value,
               size_t size, u8 cmp_op, u8 cmp_mode)
 {
     struct ceph_osd_req_op *op = osd_req_op_init(osd_req, which,
                              opcode, 0);
     struct ceph_pagelist *pagelist;
     size_t payload_len;
     int ret;
 
     BUG_ON(opcode != CEPH_OSD_OP_SETXATTR && opcode != CEPH_OSD_OP_CMPXATTR);
 
     pagelist = ceph_pagelist_alloc(GFP_NOFS);
     if (!pagelist)
         return -ENOMEM;
 
     payload_len = strlen(name);
     op->xattr.name_len = payload_len;
     ret = ceph_pagelist_append(pagelist, name, payload_len);
     if (ret)
         goto err_pagelist_free;
 
     op->xattr.value_len = size;
     ret = ceph_pagelist_append(pagelist, value, size);
     if (ret)
         goto err_pagelist_free;
     payload_len += size;
 
     op->xattr.cmp_op = cmp_op;
     op->xattr.cmp_mode = cmp_mode;
 
     ceph_osd_data_pagelist_init(&op->xattr.osd_data, pagelist);
     op->indata_len = payload_len;
     return 0;
 
 err_pagelist_free:
     ceph_pagelist_release(pagelist);
     return ret;
 }
 EXPORT_SYMBOL(osd_req_op_xattr_init);
 
 /*
  * @watch_opcode: CEPH_OSD_WATCH_OP_*
  */
 static void osd_req_op_watch_init(struct ceph_osd_request *req, int which,
                   u8 watch_opcode, u64 cookie, u32 gen)
 {
     struct ceph_osd_req_op *op;
 
     op = osd_req_op_init(req, which, CEPH_OSD_OP_WATCH, 0);
     op->watch.cookie = cookie;
     op->watch.op = watch_opcode;
     op->watch.gen = gen;
 }
 
 /*
  * prot_ver, timeout and notify payload (may be empty) should already be
  * encoded in @request_pl
  */
 static void osd_req_op_notify_init(struct ceph_osd_request *req, int which,
                    u64 cookie, struct ceph_pagelist *request_pl)
 {
     struct ceph_osd_req_op *op;
 
     op = osd_req_op_init(req, which, CEPH_OSD_OP_NOTIFY, 0);
     op->notify.cookie = cookie;
 
     ceph_osd_data_pagelist_init(&op->notify.request_data, request_pl);
     op->indata_len = request_pl->length;
 }
 
 /*
  * @flags: CEPH_OSD_OP_ALLOC_HINT_FLAG_*
  */
 void osd_req_op_alloc_hint_init(struct ceph_osd_request *osd_req,
                 unsigned int which,
                 u64 expected_object_size,
                 u64 expected_write_size,
                 u32 flags)
 {
     struct ceph_osd_req_op *op;
 
     op = osd_req_op_init(osd_req, which, CEPH_OSD_OP_SETALLOCHINT, 0);
     op->alloc_hint.expected_object_size = expected_object_size;
     op->alloc_hint.expected_write_size = expected_write_size;
     op->alloc_hint.flags = flags;
 
     /*
      * CEPH_OSD_OP_SETALLOCHINT op is advisory and therefore deemed
      * not worth a feature bit.  Set FAILOK per-op flag to make
      * sure older osds don't trip over an unsupported opcode.
      */
     op->flags |= CEPH_OSD_OP_FLAG_FAILOK;
 }
 EXPORT_SYMBOL(osd_req_op_alloc_hint_init);
 
 static void ceph_osdc_msg_data_add(struct ceph_msg *msg,
                 struct ceph_osd_data *osd_data)
 {
     u64 length = ceph_osd_data_length(osd_data);
 
     if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES) {
         BUG_ON(length > (u64) SIZE_MAX);
         if (length)
             ceph_msg_data_add_pages(msg, osd_data->pages,
                     length, osd_data->alignment, false);
     } else if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGELIST) {
         BUG_ON(!length);
         ceph_msg_data_add_pagelist(msg, osd_data->pagelist);
 #ifdef CONFIG_BLOCK
     } else if (osd_data->type == CEPH_OSD_DATA_TYPE_BIO) {
         ceph_msg_data_add_bio(msg, &osd_data->bio_pos, length);
 #endif
     } else if (osd_data->type == CEPH_OSD_DATA_TYPE_BVECS) {
         ceph_msg_data_add_bvecs(msg, &osd_data->bvec_pos);
     } else {
         BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_NONE);
     }
 }
 
 static u32 osd_req_encode_op(struct ceph_osd_op *dst,
                  const struct ceph_osd_req_op *src)
 {
     switch (src->op) {
     case CEPH_OSD_OP_STAT:
         break;
     case CEPH_OSD_OP_READ:
     case CEPH_OSD_OP_WRITE:
     case CEPH_OSD_OP_WRITEFULL:
     case CEPH_OSD_OP_ZERO:
     case CEPH_OSD_OP_TRUNCATE:
         dst->extent.offset = cpu_to_le64(src->extent.offset);
         dst->extent.length = cpu_to_le64(src->extent.length);
         dst->extent.truncate_size =
             cpu_to_le64(src->extent.truncate_size);
         dst->extent.truncate_seq =
             cpu_to_le32(src->extent.truncate_seq);
         break;
     case CEPH_OSD_OP_CALL:
         dst->cls.class_len = src->cls.class_len;
         dst->cls.method_len = src->cls.method_len;
         dst->cls.indata_len = cpu_to_le32(src->cls.indata_len);
         break;
     case CEPH_OSD_OP_WATCH:
         dst->watch.cookie = cpu_to_le64(src->watch.cookie);
         dst->watch.ver = cpu_to_le64(0);
         dst->watch.op = src->watch.op;
         dst->watch.gen = cpu_to_le32(src->watch.gen);
         break;
     case CEPH_OSD_OP_NOTIFY_ACK:
         break;
     case CEPH_OSD_OP_NOTIFY:
         dst->notify.cookie = cpu_to_le64(src->notify.cookie);
         break;
     case CEPH_OSD_OP_LIST_WATCHERS:
         break;
     case CEPH_OSD_OP_SETALLOCHINT:
         dst->alloc_hint.expected_object_size =
             cpu_to_le64(src->alloc_hint.expected_object_size);
         dst->alloc_hint.expected_write_size =
             cpu_to_le64(src->alloc_hint.expected_write_size);
         dst->alloc_hint.flags = cpu_to_le32(src->alloc_hint.flags);
         break;
     case CEPH_OSD_OP_SETXATTR:
     case CEPH_OSD_OP_CMPXATTR:
         dst->xattr.name_len = cpu_to_le32(src->xattr.name_len);
         dst->xattr.value_len = cpu_to_le32(src->xattr.value_len);
         dst->xattr.cmp_op = src->xattr.cmp_op;
         dst->xattr.cmp_mode = src->xattr.cmp_mode;
         break;
     case CEPH_OSD_OP_CREATE:
     case CEPH_OSD_OP_DELETE:
         break;
     case CEPH_OSD_OP_COPY_FROM2:
         dst->copy_from.snapid = cpu_to_le64(src->copy_from.snapid);
         dst->copy_from.src_version =
             cpu_to_le64(src->copy_from.src_version);
         dst->copy_from.flags = src->copy_from.flags;
         dst->copy_from.src_fadvise_flags =
             cpu_to_le32(src->copy_from.src_fadvise_flags);
         break;
     default:
         pr_err("unsupported osd opcode %s\n",
             ceph_osd_op_name(src->op));
         WARN_ON(1);
 
         return 0;
     }
 
     dst->op = cpu_to_le16(src->op);
     dst->flags = cpu_to_le32(src->flags);
     dst->payload_len = cpu_to_le32(src->indata_len);
 
     return src->indata_len;
 }
 
 /*
  * build new request AND message, calculate layout, and adjust file
  * extent as needed.
  *
  * if the file was recently truncated, we include information about its
  * old and new size so that the object can be updated appropriately.  (we
  * avoid synchronously deleting truncated objects because it's slow.)
  */
 struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
                            struct ceph_file_layout *layout,
                            struct ceph_vino vino,
                            u64 off, u64 *plen,
                            unsigned int which, int num_ops,
                            int opcode, int flags,
                            struct ceph_snap_context *snapc,
                            u32 truncate_seq,
                            u64 truncate_size,
                            bool use_mempool)
 {
     struct ceph_osd_request *req;
     u64 objnum = 0;
     u64 objoff = 0;
     u64 objlen = 0;
     int r;
 
     BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
            opcode != CEPH_OSD_OP_ZERO && opcode != CEPH_OSD_OP_TRUNCATE &&
            opcode != CEPH_OSD_OP_CREATE && opcode != CEPH_OSD_OP_DELETE);
 
     req = ceph_osdc_alloc_request(osdc, snapc, num_ops, use_mempool,
                     GFP_NOFS);
     if (!req) {
         r = -ENOMEM;
         goto fail;
     }
 
     /* calculate max write size */
     r = calc_layout(layout, off, plen, &objnum, &objoff, &objlen);
     if (r)
         goto fail;
 
     if (opcode == CEPH_OSD_OP_CREATE || opcode == CEPH_OSD_OP_DELETE) {
         osd_req_op_init(req, which, opcode, 0);
     } else {
         u32 object_size = layout->object_size;
         u32 object_base = off - objoff;
         if (!(truncate_seq == 1 && truncate_size == -1ULL)) {
             if (truncate_size <= object_base) {
                 truncate_size = 0;
             } else {
                 truncate_size -= object_base;
                 if (truncate_size > object_size)
                     truncate_size = object_size;
             }
         }
         osd_req_op_extent_init(req, which, opcode, objoff, objlen,
                        truncate_size, truncate_seq);
     }
 
     req->r_base_oloc.pool = layout->pool_id;
     req->r_base_oloc.pool_ns = ceph_try_get_string(layout->pool_ns);
     ceph_oid_printf(&req->r_base_oid, "%llx.%08llx", vino.ino, objnum);
     req->r_flags = flags | osdc->client->options->read_from_replica;
 
     req->r_snapid = vino.snap;
     if (flags & CEPH_OSD_FLAG_WRITE)
         req->r_data_offset = off;
 
     if (num_ops > 1)
         /*
          * This is a special case for ceph_writepages_start(), but it
          * also covers ceph_uninline_data().  If more multi-op request
          * use cases emerge, we will need a separate helper.
          */
         r = __ceph_osdc_alloc_messages(req, GFP_NOFS, num_ops, 0);
     else
         r = ceph_osdc_alloc_messages(req, GFP_NOFS);
     if (r)
         goto fail;
 
     return req;
 
 fail:
     ceph_osdc_put_request(req);
     return ERR_PTR(r);
 }
 EXPORT_SYMBOL(ceph_osdc_new_request);
 
 /*
  * We keep osd requests in an rbtree, sorted by ->r_tid.
  */
 DEFINE_RB_FUNCS(request, struct ceph_osd_request, r_tid, r_node)
 DEFINE_RB_FUNCS(request_mc, struct ceph_osd_request, r_tid, r_mc_node)
 
 /*
  * Call @fn on each OSD request as long as @fn returns 0.
  */
 static void for_each_request(struct ceph_osd_client *osdc,
             int (*fn)(struct ceph_osd_request *req, void *arg),
             void *arg)
 {
     struct rb_node *n, *p;
 
     for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
         struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
 
         for (p = rb_first(&osd->o_requests); p; ) {
             struct ceph_osd_request *req =
                 rb_entry(p, struct ceph_osd_request, r_node);
 
             p = rb_next(p);
             if (fn(req, arg))
                 return;
         }
     }
 
     for (p = rb_first(&osdc->homeless_osd.o_requests); p; ) {
         struct ceph_osd_request *req =
             rb_entry(p, struct ceph_osd_request, r_node);
 
         p = rb_next(p);
         if (fn(req, arg))
             return;
     }
 }
 
 static bool osd_homeless(struct ceph_osd *osd)
 {
     return osd->o_osd == CEPH_HOMELESS_OSD;
 }
 
 static bool osd_registered(struct ceph_osd *osd)
 {
     verify_osdc_locked(osd->o_osdc);
 
     return !RB_EMPTY_NODE(&osd->o_node);
 }
 
 /*
  * Assumes @osd is zero-initialized.
  */
 static void osd_init(struct ceph_osd *osd)
 {
     refcount_set(&osd->o_ref, 1);
     RB_CLEAR_NODE(&osd->o_node);
     osd->o_requests = RB_ROOT;
     osd->o_linger_requests = RB_ROOT;
     osd->o_backoff_mappings = RB_ROOT;
     osd->o_backoffs_by_id = RB_ROOT;
     INIT_LIST_HEAD(&osd->o_osd_lru);
     INIT_LIST_HEAD(&osd->o_keepalive_item);
     osd->o_incarnation = 1;
     mutex_init(&osd->lock);
 }
 
 static void osd_cleanup(struct ceph_osd *osd)
 {
     WARN_ON(!RB_EMPTY_NODE(&osd->o_node));
     WARN_ON(!RB_EMPTY_ROOT(&osd->o_requests));
     WARN_ON(!RB_EMPTY_ROOT(&osd->o_linger_requests));
     WARN_ON(!RB_EMPTY_ROOT(&osd->o_backoff_mappings));
     WARN_ON(!RB_EMPTY_ROOT(&osd->o_backoffs_by_id));
     WARN_ON(!list_empty(&osd->o_osd_lru));
     WARN_ON(!list_empty(&osd->o_keepalive_item));
 
     if (osd->o_auth.authorizer) {
         WARN_ON(osd_homeless(osd));
         ceph_auth_destroy_authorizer(osd->o_auth.authorizer);
     }
 }
 
 /*
  * Track open sessions with osds.
  */
 static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
 {
     struct ceph_osd *osd;
 
     WARN_ON(onum == CEPH_HOMELESS_OSD);
 
     osd = kzalloc(sizeof(*osd), GFP_NOIO | __GFP_NOFAIL);
     osd_init(osd);
     osd->o_osdc = osdc;
     osd->o_osd = onum;
 
     ceph_con_init(&osd->o_con, osd, &osd_con_ops, &osdc->client->msgr);
 
     return osd;
 }
 
 static struct ceph_osd *get_osd(struct ceph_osd *osd)
 {
     if (refcount_inc_not_zero(&osd->o_ref)) {
         dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
              refcount_read(&osd->o_ref));
         return osd;
     } else {
         dout("get_osd %p FAIL\n", osd);
         return NULL;
     }
 }
 
 static void put_osd(struct ceph_osd *osd)
 {
     dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
          refcount_read(&osd->o_ref) - 1);
     if (refcount_dec_and_test(&osd->o_ref)) {
         osd_cleanup(osd);
         kfree(osd);
     }
 }
 
 DEFINE_RB_FUNCS(osd, struct ceph_osd, o_osd, o_node)
 
 static void __move_osd_to_lru(struct ceph_osd *osd)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
 
     dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
     BUG_ON(!list_empty(&osd->o_osd_lru));
 
     spin_lock(&osdc->osd_lru_lock);
     list_add_tail(&osd->o_osd_lru, &osdc->osd_lru);
     spin_unlock(&osdc->osd_lru_lock);
 
     osd->lru_ttl = jiffies + osdc->client->options->osd_idle_ttl;
 }
 
 static void maybe_move_osd_to_lru(struct ceph_osd *osd)
 {
     if (RB_EMPTY_ROOT(&osd->o_requests) &&
         RB_EMPTY_ROOT(&osd->o_linger_requests))
         __move_osd_to_lru(osd);
 }
 
 static void __remove_osd_from_lru(struct ceph_osd *osd)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
 
     dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
 
     spin_lock(&osdc->osd_lru_lock);
     if (!list_empty(&osd->o_osd_lru))
         list_del_init(&osd->o_osd_lru);
     spin_unlock(&osdc->osd_lru_lock);
 }
 
 /*
  * Close the connection and assign any leftover requests to the
  * homeless session.
  */
 static void close_osd(struct ceph_osd *osd)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
     struct rb_node *n;
 
     verify_osdc_wrlocked(osdc);
     dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
 
     ceph_con_close(&osd->o_con);
 
     for (n = rb_first(&osd->o_requests); n; ) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
 
         n = rb_next(n); /* unlink_request() */
 
         dout(" reassigning req %p tid %llu\n", req, req->r_tid);
         unlink_request(osd, req);
         link_request(&osdc->homeless_osd, req);
     }
     for (n = rb_first(&osd->o_linger_requests); n; ) {
         struct ceph_osd_linger_request *lreq =
             rb_entry(n, struct ceph_osd_linger_request, node);
 
         n = rb_next(n); /* unlink_linger() */
 
         dout(" reassigning lreq %p linger_id %llu\n", lreq,
              lreq->linger_id);
         unlink_linger(osd, lreq);
         link_linger(&osdc->homeless_osd, lreq);
     }
     clear_backoffs(osd);
 
     __remove_osd_from_lru(osd);
     erase_osd(&osdc->osds, osd);
     put_osd(osd);
 }
 
 /*
  * reset osd connect
  */
 static int reopen_osd(struct ceph_osd *osd)
 {
     struct ceph_entity_addr *peer_addr;
 
     dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
 
     if (RB_EMPTY_ROOT(&osd->o_requests) &&
         RB_EMPTY_ROOT(&osd->o_linger_requests)) {
         close_osd(osd);
         return -ENODEV;
     }
 
     peer_addr = &osd->o_osdc->osdmap->osd_addr[osd->o_osd];
     if (!memcmp(peer_addr, &osd->o_con.peer_addr, sizeof (*peer_addr)) &&
             !ceph_con_opened(&osd->o_con)) {
         struct rb_node *n;
 
         dout("osd addr hasn't changed and connection never opened, "
              "letting msgr retry\n");
         /* touch each r_stamp for handle_timeout()'s benfit */
         for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
             struct ceph_osd_request *req =
                 rb_entry(n, struct ceph_osd_request, r_node);
             req->r_stamp = jiffies;
         }
 
         return -EAGAIN;
     }
 
     ceph_con_close(&osd->o_con);
     ceph_con_open(&osd->o_con, CEPH_ENTITY_TYPE_OSD, osd->o_osd, peer_addr);
     osd->o_incarnation++;
 
     return 0;
 }
 
 static struct ceph_osd *lookup_create_osd(struct ceph_osd_client *osdc, int o,
                       bool wrlocked)
 {
     struct ceph_osd *osd;
 
     if (wrlocked)
         verify_osdc_wrlocked(osdc);
     else
         verify_osdc_locked(osdc);
 
     if (o != CEPH_HOMELESS_OSD)
         osd = lookup_osd(&osdc->osds, o);
     else
         osd = &osdc->homeless_osd;
     if (!osd) {
         if (!wrlocked)
             return ERR_PTR(-EAGAIN);
 
         osd = create_osd(osdc, o);
         insert_osd(&osdc->osds, osd);
         ceph_con_open(&osd->o_con, CEPH_ENTITY_TYPE_OSD, osd->o_osd,
                   &osdc->osdmap->osd_addr[osd->o_osd]);
     }
 
     dout("%s osdc %p osd%d -> osd %p\n", __func__, osdc, o, osd);
     return osd;
 }
 
 /*
  * Create request <-> OSD session relation.
  *
  * @req has to be assigned a tid, @osd may be homeless.
  */
 static void link_request(struct ceph_osd *osd, struct ceph_osd_request *req)
 {
     verify_osd_locked(osd);
     WARN_ON(!req->r_tid || req->r_osd);
     dout("%s osd %p osd%d req %p tid %llu\n", __func__, osd, osd->o_osd,
          req, req->r_tid);
 
     if (!osd_homeless(osd))
         __remove_osd_from_lru(osd);
     else
         atomic_inc(&osd->o_osdc->num_homeless);
 
     get_osd(osd);
     insert_request(&osd->o_requests, req);
     req->r_osd = osd;
 }
 
 static void unlink_request(struct ceph_osd *osd, struct ceph_osd_request *req)
 {
     verify_osd_locked(osd);
     WARN_ON(req->r_osd != osd);
     dout("%s osd %p osd%d req %p tid %llu\n", __func__, osd, osd->o_osd,
          req, req->r_tid);
 
     req->r_osd = NULL;
     erase_request(&osd->o_requests, req);
     put_osd(osd);
 
     if (!osd_homeless(osd))
         maybe_move_osd_to_lru(osd);
     else
         atomic_dec(&osd->o_osdc->num_homeless);
 }
 
 static bool __pool_full(struct ceph_pg_pool_info *pi)
 {
     return pi->flags & CEPH_POOL_FLAG_FULL;
 }
 
 static bool have_pool_full(struct ceph_osd_client *osdc)
 {
     struct rb_node *n;
 
     for (n = rb_first(&osdc->osdmap->pg_pools); n; n = rb_next(n)) {
         struct ceph_pg_pool_info *pi =
             rb_entry(n, struct ceph_pg_pool_info, node);
 
         if (__pool_full(pi))
             return true;
     }
 
     return false;
 }
 
 static bool pool_full(struct ceph_osd_client *osdc, s64 pool_id)
 {
     struct ceph_pg_pool_info *pi;
 
     pi = ceph_pg_pool_by_id(osdc->osdmap, pool_id);
     if (!pi)
         return false;
 
     return __pool_full(pi);
 }
 
 /*
  * Returns whether a request should be blocked from being sent
  * based on the current osdmap and osd_client settings.
  */
 static bool target_should_be_paused(struct ceph_osd_client *osdc,
                     const struct ceph_osd_request_target *t,
                     struct ceph_pg_pool_info *pi)
 {
     bool pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
     bool pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
                ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
                __pool_full(pi);
 
     WARN_ON(pi->id != t->target_oloc.pool);
     return ((t->flags & CEPH_OSD_FLAG_READ) && pauserd) ||
            ((t->flags & CEPH_OSD_FLAG_WRITE) && pausewr) ||
            (osdc->osdmap->epoch < osdc->epoch_barrier);
 }
 
 static int pick_random_replica(const struct ceph_osds *acting)
 {
     int i = prandom_u32() % acting->size;
 
     dout("%s picked osd%d, primary osd%d\n", __func__,
          acting->osds[i], acting->primary);
     return i;
 }
 
 /*
  * Picks the closest replica based on client's location given by
  * crush_location option.  Prefers the primary if the locality is
  * the same.
  */
 static int pick_closest_replica(struct ceph_osd_client *osdc,
                 const struct ceph_osds *acting)
 {
     struct ceph_options *opt = osdc->client->options;
     int best_i, best_locality;
     int i = 0, locality;
 
     do {
         locality = ceph_get_crush_locality(osdc->osdmap,
                            acting->osds[i],
                            &opt->crush_locs);
         if (i == 0 ||
             (locality >= 0 && best_locality < 0) ||
             (locality >= 0 && best_locality >= 0 &&
              locality < best_locality)) {
             best_i = i;
             best_locality = locality;
         }
     } while (++i < acting->size);
 
     dout("%s picked osd%d with locality %d, primary osd%d\n", __func__,
          acting->osds[best_i], best_locality, acting->primary);
     return best_i;
 }
 
 enum calc_target_result {
     CALC_TARGET_NO_ACTION = 0,
     CALC_TARGET_NEED_RESEND,
     CALC_TARGET_POOL_DNE,
 };
 
 static enum calc_target_result calc_target(struct ceph_osd_client *osdc,
                        struct ceph_osd_request_target *t,
                        bool any_change)
 {
     struct ceph_pg_pool_info *pi;
     struct ceph_pg pgid, last_pgid;
     struct ceph_osds up, acting;
     bool is_read = t->flags & CEPH_OSD_FLAG_READ;
     bool is_write = t->flags & CEPH_OSD_FLAG_WRITE;
     bool force_resend = false;
     bool unpaused = false;
     bool legacy_change = false;
     bool split = false;
     bool sort_bitwise = ceph_osdmap_flag(osdc, CEPH_OSDMAP_SORTBITWISE);
     bool recovery_deletes = ceph_osdmap_flag(osdc,
                          CEPH_OSDMAP_RECOVERY_DELETES);
     enum calc_target_result ct_res;
 
     t->epoch = osdc->osdmap->epoch;
     pi = ceph_pg_pool_by_id(osdc->osdmap, t->base_oloc.pool);
     if (!pi) {
         t->osd = CEPH_HOMELESS_OSD;
         ct_res = CALC_TARGET_POOL_DNE;
         goto out;
     }
 
     if (osdc->osdmap->epoch == pi->last_force_request_resend) {
         if (t->last_force_resend < pi->last_force_request_resend) {
             t->last_force_resend = pi->last_force_request_resend;
             force_resend = true;
         } else if (t->last_force_resend == 0) {
             force_resend = true;
         }
     }
 
     /* apply tiering */
     ceph_oid_copy(&t->target_oid, &t->base_oid);
     ceph_oloc_copy(&t->target_oloc, &t->base_oloc);
     if ((t->flags & CEPH_OSD_FLAG_IGNORE_OVERLAY) == 0) {
         if (is_read && pi->read_tier >= 0)
             t->target_oloc.pool = pi->read_tier;
         if (is_write && pi->write_tier >= 0)
             t->target_oloc.pool = pi->write_tier;
 
         pi = ceph_pg_pool_by_id(osdc->osdmap, t->target_oloc.pool);
         if (!pi) {
             t->osd = CEPH_HOMELESS_OSD;
             ct_res = CALC_TARGET_POOL_DNE;
             goto out;
         }
     }
 
     __ceph_object_locator_to_pg(pi, &t->target_oid, &t->target_oloc, &pgid);
     last_pgid.pool = pgid.pool;
     last_pgid.seed = ceph_stable_mod(pgid.seed, t->pg_num, t->pg_num_mask);
 
     ceph_pg_to_up_acting_osds(osdc->osdmap, pi, &pgid, &up, &acting);
     if (any_change &&
         ceph_is_new_interval(&t->acting,
                  &acting,
                  &t->up,
                  &up,
                  t->size,
                  pi->size,
                  t->min_size,
                  pi->min_size,
                  t->pg_num,
                  pi->pg_num,
                  t->sort_bitwise,
                  sort_bitwise,
                  t->recovery_deletes,
                  recovery_deletes,
                  &last_pgid))
         force_resend = true;
 
     if (t->paused && !target_should_be_paused(osdc, t, pi)) {
         t->paused = false;
         unpaused = true;
     }
     legacy_change = ceph_pg_compare(&t->pgid, &pgid) ||
             ceph_osds_changed(&t->acting, &acting,
                       t->used_replica || any_change);
     if (t->pg_num)
         split = ceph_pg_is_split(&last_pgid, t->pg_num, pi->pg_num);
 
     if (legacy_change || force_resend || split) {
         t->pgid = pgid; /* struct */
         ceph_pg_to_primary_shard(osdc->osdmap, pi, &pgid, &t->spgid);
         ceph_osds_copy(&t->acting, &acting);
         ceph_osds_copy(&t->up, &up);
         t->size = pi->size;
         t->min_size = pi->min_size;
         t->pg_num = pi->pg_num;
         t->pg_num_mask = pi->pg_num_mask;
         t->sort_bitwise = sort_bitwise;
         t->recovery_deletes = recovery_deletes;
 
         if ((t->flags & (CEPH_OSD_FLAG_BALANCE_READS |
                  CEPH_OSD_FLAG_LOCALIZE_READS)) &&
             !is_write && pi->type == CEPH_POOL_TYPE_REP &&
             acting.size > 1) {
             int pos;
 
             WARN_ON(!is_read || acting.osds[0] != acting.primary);
             if (t->flags & CEPH_OSD_FLAG_BALANCE_READS) {
                 pos = pick_random_replica(&acting);
             } else {
                 pos = pick_closest_replica(osdc, &acting);
             }
             t->osd = acting.osds[pos];
             t->used_replica = pos > 0;
         } else {
             t->osd = acting.primary;
             t->used_replica = false;
         }
     }
 
     if (unpaused || legacy_change || force_resend || split)
         ct_res = CALC_TARGET_NEED_RESEND;
     else
         ct_res = CALC_TARGET_NO_ACTION;
 
 out:
     dout("%s t %p -> %d%d%d%d ct_res %d osd%d\n", __func__, t, unpaused,
          legacy_change, force_resend, split, ct_res, t->osd);
     return ct_res;
 }
 
 static struct ceph_spg_mapping *alloc_spg_mapping(void)
 {
     struct ceph_spg_mapping *spg;
 
     spg = kmalloc(sizeof(*spg), GFP_NOIO);
     if (!spg)
         return NULL;
 
     RB_CLEAR_NODE(&spg->node);
     spg->backoffs = RB_ROOT;
     return spg;
 }
 
 static void free_spg_mapping(struct ceph_spg_mapping *spg)
 {
     WARN_ON(!RB_EMPTY_NODE(&spg->node));
     WARN_ON(!RB_EMPTY_ROOT(&spg->backoffs));
 
     kfree(spg);
 }
 
 /*
  * rbtree of ceph_spg_mapping for handling map<spg_t, ...>, similar to
  * ceph_pg_mapping.  Used to track OSD backoffs -- a backoff [range] is
  * defined only within a specific spgid; it does not pass anything to
  * children on split, or to another primary.
  */
 DEFINE_RB_FUNCS2(spg_mapping, struct ceph_spg_mapping, spgid, ceph_spg_compare,
          RB_BYPTR, const struct ceph_spg *, node)
 
 static u64 hoid_get_bitwise_key(const struct ceph_hobject_id *hoid)
 {
     return hoid->is_max ? 0x100000000ull : hoid->hash_reverse_bits;
 }
 
 static void hoid_get_effective_key(const struct ceph_hobject_id *hoid,
                    void **pkey, size_t *pkey_len)
 {
     if (hoid->key_len) {
         *pkey = hoid->key;
         *pkey_len = hoid->key_len;
     } else {
         *pkey = hoid->oid;
         *pkey_len = hoid->oid_len;
     }
 }
 
 static int compare_names(const void *name1, size_t name1_len,
              const void *name2, size_t name2_len)
 {
     int ret;
 
     ret = memcmp(name1, name2, min(name1_len, name2_len));
     if (!ret) {
         if (name1_len < name2_len)
             ret = -1;
         else if (name1_len > name2_len)
             ret = 1;
     }
     return ret;
 }
 
 static int hoid_compare(const struct ceph_hobject_id *lhs,
             const struct ceph_hobject_id *rhs)
 {
     void *effective_key1, *effective_key2;
     size_t effective_key1_len, effective_key2_len;
     int ret;
 
     if (lhs->is_max < rhs->is_max)
         return -1;
     if (lhs->is_max > rhs->is_max)
         return 1;
 
     if (lhs->pool < rhs->pool)
         return -1;
     if (lhs->pool > rhs->pool)
         return 1;
 
     if (hoid_get_bitwise_key(lhs) < hoid_get_bitwise_key(rhs))
         return -1;
     if (hoid_get_bitwise_key(lhs) > hoid_get_bitwise_key(rhs))
         return 1;
 
     ret = compare_names(lhs->nspace, lhs->nspace_len,
                 rhs->nspace, rhs->nspace_len);
     if (ret)
         return ret;
 
     hoid_get_effective_key(lhs, &effective_key1, &effective_key1_len);
     hoid_get_effective_key(rhs, &effective_key2, &effective_key2_len);
     ret = compare_names(effective_key1, effective_key1_len,
                 effective_key2, effective_key2_len);
     if (ret)
         return ret;
 
     ret = compare_names(lhs->oid, lhs->oid_len, rhs->oid, rhs->oid_len);
     if (ret)
         return ret;
 
     if (lhs->snapid < rhs->snapid)
         return -1;
     if (lhs->snapid > rhs->snapid)
         return 1;
 
     return 0;
 }
 
 /*
  * For decoding ->begin and ->end of MOSDBackoff only -- no MIN/MAX
  * compat stuff here.
  *
  * Assumes @hoid is zero-initialized.
  */
 static int decode_hoid(void **p, void *end, struct ceph_hobject_id *hoid)
 {
     u8 struct_v;
     u32 struct_len;
     int ret;
 
     ret = ceph_start_decoding(p, end, 4, "hobject_t", &struct_v,
                   &struct_len);
     if (ret)
         return ret;
 
     if (struct_v < 4) {
         pr_err("got struct_v %d < 4 of hobject_t\n", struct_v);
         goto e_inval;
     }
 
     hoid->key = ceph_extract_encoded_string(p, end, &hoid->key_len,
                         GFP_NOIO);
     if (IS_ERR(hoid->key)) {
         ret = PTR_ERR(hoid->key);
         hoid->key = NULL;
         return ret;
     }
 
     hoid->oid = ceph_extract_encoded_string(p, end, &hoid->oid_len,
                         GFP_NOIO);
     if (IS_ERR(hoid->oid)) {
         ret = PTR_ERR(hoid->oid);
         hoid->oid = NULL;
         return ret;
     }
 
     ceph_decode_64_safe(p, end, hoid->snapid, e_inval);
     ceph_decode_32_safe(p, end, hoid->hash, e_inval);
     ceph_decode_8_safe(p, end, hoid->is_max, e_inval);
 
     hoid->nspace = ceph_extract_encoded_string(p, end, &hoid->nspace_len,
                            GFP_NOIO);
     if (IS_ERR(hoid->nspace)) {
         ret = PTR_ERR(hoid->nspace);
         hoid->nspace = NULL;
         return ret;
     }
 
     ceph_decode_64_safe(p, end, hoid->pool, e_inval);
 
     ceph_hoid_build_hash_cache(hoid);
     return 0;
 
 e_inval:
     return -EINVAL;
 }
 
 static int hoid_encoding_size(const struct ceph_hobject_id *hoid)
 {
     return 8 + 4 + 1 + 8 + /* snapid, hash, is_max, pool */
            4 + hoid->key_len + 4 + hoid->oid_len + 4 + hoid->nspace_len;
 }
 
 static void encode_hoid(void **p, void *end, const struct ceph_hobject_id *hoid)
 {
     ceph_start_encoding(p, 4, 3, hoid_encoding_size(hoid));
     ceph_encode_string(p, end, hoid->key, hoid->key_len);
     ceph_encode_string(p, end, hoid->oid, hoid->oid_len);
     ceph_encode_64(p, hoid->snapid);
     ceph_encode_32(p, hoid->hash);
     ceph_encode_8(p, hoid->is_max);
     ceph_encode_string(p, end, hoid->nspace, hoid->nspace_len);
     ceph_encode_64(p, hoid->pool);
 }
 
 static void free_hoid(struct ceph_hobject_id *hoid)
 {
     if (hoid) {
         kfree(hoid->key);
         kfree(hoid->oid);
         kfree(hoid->nspace);
         kfree(hoid);
     }
 }
 
 static struct ceph_osd_backoff *alloc_backoff(void)
 {
     struct ceph_osd_backoff *backoff;
 
     backoff = kzalloc(sizeof(*backoff), GFP_NOIO);
     if (!backoff)
         return NULL;
 
     RB_CLEAR_NODE(&backoff->spg_node);
     RB_CLEAR_NODE(&backoff->id_node);
     return backoff;
 }
 
 static void free_backoff(struct ceph_osd_backoff *backoff)
 {
     WARN_ON(!RB_EMPTY_NODE(&backoff->spg_node));
     WARN_ON(!RB_EMPTY_NODE(&backoff->id_node));
 
     free_hoid(backoff->begin);
     free_hoid(backoff->end);
     kfree(backoff);
 }
 
 /*
  * Within a specific spgid, backoffs are managed by ->begin hoid.
  */
 DEFINE_RB_INSDEL_FUNCS2(backoff, struct ceph_osd_backoff, begin, hoid_compare,
             RB_BYVAL, spg_node);
 
 static struct ceph_osd_backoff *lookup_containing_backoff(struct rb_root *root,
                         const struct ceph_hobject_id *hoid)
 {
     struct rb_node *n = root->rb_node;
 
     while (n) {
         struct ceph_osd_backoff *cur =
             rb_entry(n, struct ceph_osd_backoff, spg_node);
         int cmp;
 
         cmp = hoid_compare(hoid, cur->begin);
         if (cmp < 0) {
             n = n->rb_left;
         } else if (cmp > 0) {
             if (hoid_compare(hoid, cur->end) < 0)
                 return cur;
 
             n = n->rb_right;
         } else {
             return cur;
         }
     }
 
     return NULL;
 }
 
 /*
  * Each backoff has a unique id within its OSD session.
  */
 DEFINE_RB_FUNCS(backoff_by_id, struct ceph_osd_backoff, id, id_node)
 
 static void clear_backoffs(struct ceph_osd *osd)
 {
     while (!RB_EMPTY_ROOT(&osd->o_backoff_mappings)) {
         struct ceph_spg_mapping *spg =
             rb_entry(rb_first(&osd->o_backoff_mappings),
                  struct ceph_spg_mapping, node);
 
         while (!RB_EMPTY_ROOT(&spg->backoffs)) {
             struct ceph_osd_backoff *backoff =
                 rb_entry(rb_first(&spg->backoffs),
                      struct ceph_osd_backoff, spg_node);
 
             erase_backoff(&spg->backoffs, backoff);
             erase_backoff_by_id(&osd->o_backoffs_by_id, backoff);
             free_backoff(backoff);
         }
         erase_spg_mapping(&osd->o_backoff_mappings, spg);
         free_spg_mapping(spg);
     }
 }
 
 /*
  * Set up a temporary, non-owning view into @t.
  */
 static void hoid_fill_from_target(struct ceph_hobject_id *hoid,
                   const struct ceph_osd_request_target *t)
 {
     hoid->key = NULL;
     hoid->key_len = 0;
     hoid->oid = t->target_oid.name;
     hoid->oid_len = t->target_oid.name_len;
     hoid->snapid = CEPH_NOSNAP;
     hoid->hash = t->pgid.seed;
     hoid->is_max = false;
     if (t->target_oloc.pool_ns) {
         hoid->nspace = t->target_oloc.pool_ns->str;
         hoid->nspace_len = t->target_oloc.pool_ns->len;
     } else {
         hoid->nspace = NULL;
         hoid->nspace_len = 0;
     }
     hoid->pool = t->target_oloc.pool;
     ceph_hoid_build_hash_cache(hoid);
 }
 
 static bool should_plug_request(struct ceph_osd_request *req)
 {
     struct ceph_osd *osd = req->r_osd;
     struct ceph_spg_mapping *spg;
     struct ceph_osd_backoff *backoff;
     struct ceph_hobject_id hoid;
 
     spg = lookup_spg_mapping(&osd->o_backoff_mappings, &req->r_t.spgid);
     if (!spg)
         return false;
 
     hoid_fill_from_target(&hoid, &req->r_t);
     backoff = lookup_containing_backoff(&spg->backoffs, &hoid);
     if (!backoff)
         return false;
 
     dout("%s req %p tid %llu backoff osd%d spgid %llu.%xs%d id %llu\n",
          __func__, req, req->r_tid, osd->o_osd, backoff->spgid.pgid.pool,
          backoff->spgid.pgid.seed, backoff->spgid.shard, backoff->id);
     return true;
 }
 
 /*
  * Keep get_num_data_items() in sync with this function.
  */
 static void setup_request_data(struct ceph_osd_request *req)
 {
     struct ceph_msg *request_msg = req->r_request;
     struct ceph_msg *reply_msg = req->r_reply;
     struct ceph_osd_req_op *op;
 
     if (req->r_request->num_data_items || req->r_reply->num_data_items)
         return;
 
     WARN_ON(request_msg->data_length || reply_msg->data_length);
     for (op = req->r_ops; op != &req->r_ops[req->r_num_ops]; op++) {
         switch (op->op) {
         /* request */
         case CEPH_OSD_OP_WRITE:
         case CEPH_OSD_OP_WRITEFULL:
             WARN_ON(op->indata_len != op->extent.length);
             ceph_osdc_msg_data_add(request_msg,
                            &op->extent.osd_data);
             break;
         case CEPH_OSD_OP_SETXATTR:
         case CEPH_OSD_OP_CMPXATTR:
             WARN_ON(op->indata_len != op->xattr.name_len +
                           op->xattr.value_len);
             ceph_osdc_msg_data_add(request_msg,
                            &op->xattr.osd_data);
             break;
         case CEPH_OSD_OP_NOTIFY_ACK:
             ceph_osdc_msg_data_add(request_msg,
                            &op->notify_ack.request_data);
             break;
         case CEPH_OSD_OP_COPY_FROM2:
             ceph_osdc_msg_data_add(request_msg,
                            &op->copy_from.osd_data);
             break;
 
         /* reply */
         case CEPH_OSD_OP_STAT:
             ceph_osdc_msg_data_add(reply_msg,
                            &op->raw_data_in);
             break;
         case CEPH_OSD_OP_READ:
             ceph_osdc_msg_data_add(reply_msg,
                            &op->extent.osd_data);
             break;
         case CEPH_OSD_OP_LIST_WATCHERS:
             ceph_osdc_msg_data_add(reply_msg,
                            &op->list_watchers.response_data);
             break;
 
         /* both */
         case CEPH_OSD_OP_CALL:
             WARN_ON(op->indata_len != op->cls.class_len +
                           op->cls.method_len +
                           op->cls.indata_len);
             ceph_osdc_msg_data_add(request_msg,
                            &op->cls.request_info);
             /* optional, can be NONE */
             ceph_osdc_msg_data_add(request_msg,
                            &op->cls.request_data);
             /* optional, can be NONE */
             ceph_osdc_msg_data_add(reply_msg,
                            &op->cls.response_data);
             break;
         case CEPH_OSD_OP_NOTIFY:
             ceph_osdc_msg_data_add(request_msg,
                            &op->notify.request_data);
             ceph_osdc_msg_data_add(reply_msg,
                            &op->notify.response_data);
             break;
         }
     }
 }
 
 static void encode_pgid(void **p, const struct ceph_pg *pgid)
 {
     ceph_encode_8(p, 1);
     ceph_encode_64(p, pgid->pool);
     ceph_encode_32(p, pgid->seed);
     ceph_encode_32(p, -1); /* preferred */
 }
 
 static void encode_spgid(void **p, const struct ceph_spg *spgid)
 {
     ceph_start_encoding(p, 1, 1, CEPH_PGID_ENCODING_LEN + 1);
     encode_pgid(p, &spgid->pgid);
     ceph_encode_8(p, spgid->shard);
 }
 
 static void encode_oloc(void **p, void *end,
             const struct ceph_object_locator *oloc)
 {
     ceph_start_encoding(p, 5, 4, ceph_oloc_encoding_size(oloc));
     ceph_encode_64(p, oloc->pool);
     ceph_encode_32(p, -1); /* preferred */
     ceph_encode_32(p, 0);  /* key len */
     if (oloc->pool_ns)
         ceph_encode_string(p, end, oloc->pool_ns->str,
                    oloc->pool_ns->len);
     else
         ceph_encode_32(p, 0);
 }
 
 static void encode_request_partial(struct ceph_osd_request *req,
                    struct ceph_msg *msg)
 {
     void *p = msg->front.iov_base;
     void *const end = p + msg->front_alloc_len;
     u32 data_len = 0;
     int i;
 
     if (req->r_flags & CEPH_OSD_FLAG_WRITE) {
         /* snapshots aren't writeable */
         WARN_ON(req->r_snapid != CEPH_NOSNAP);
     } else {
         WARN_ON(req->r_mtime.tv_sec || req->r_mtime.tv_nsec ||
             req->r_data_offset || req->r_snapc);
     }
 
     setup_request_data(req);
 
     encode_spgid(&p, &req->r_t.spgid); /* actual spg */
     ceph_encode_32(&p, req->r_t.pgid.seed); /* raw hash */
     ceph_encode_32(&p, req->r_osdc->osdmap->epoch);
     ceph_encode_32(&p, req->r_flags);
 
     /* reqid */
     ceph_start_encoding(&p, 2, 2, sizeof(struct ceph_osd_reqid));
     memset(p, 0, sizeof(struct ceph_osd_reqid));
     p += sizeof(struct ceph_osd_reqid);
 
     /* trace */
     memset(p, 0, sizeof(struct ceph_blkin_trace_info));
     p += sizeof(struct ceph_blkin_trace_info);
 
     ceph_encode_32(&p, 0); /* client_inc, always 0 */
     ceph_encode_timespec64(p, &req->r_mtime);
     p += sizeof(struct ceph_timespec);
 
     encode_oloc(&p, end, &req->r_t.target_oloc);
     ceph_encode_string(&p, end, req->r_t.target_oid.name,
                req->r_t.target_oid.name_len);
 
     /* ops, can imply data */
     ceph_encode_16(&p, req->r_num_ops);
     for (i = 0; i < req->r_num_ops; i++) {
         data_len += osd_req_encode_op(p, &req->r_ops[i]);
         p += sizeof(struct ceph_osd_op);
     }
 
     ceph_encode_64(&p, req->r_snapid); /* snapid */
     if (req->r_snapc) {
         ceph_encode_64(&p, req->r_snapc->seq);
         ceph_encode_32(&p, req->r_snapc->num_snaps);
         for (i = 0; i < req->r_snapc->num_snaps; i++)
             ceph_encode_64(&p, req->r_snapc->snaps[i]);
     } else {
         ceph_encode_64(&p, 0); /* snap_seq */
         ceph_encode_32(&p, 0); /* snaps len */
     }
 
     ceph_encode_32(&p, req->r_attempts); /* retry_attempt */
     BUG_ON(p > end - 8); /* space for features */
 
     msg->hdr.version = cpu_to_le16(8); /* MOSDOp v8 */
     /* front_len is finalized in encode_request_finish() */
     msg->front.iov_len = p - msg->front.iov_base;
     msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
     msg->hdr.data_len = cpu_to_le32(data_len);
     /*
      * The header "data_off" is a hint to the receiver allowing it
      * to align received data into its buffers such that there's no
      * need to re-copy it before writing it to disk (direct I/O).
      */
     msg->hdr.data_off = cpu_to_le16(req->r_data_offset);
 
     dout("%s req %p msg %p oid %s oid_len %d\n", __func__, req, msg,
          req->r_t.target_oid.name, req->r_t.target_oid.name_len);
 }
 
 static void encode_request_finish(struct ceph_msg *msg)
 {
     void *p = msg->front.iov_base;
     void *const partial_end = p + msg->front.iov_len;
     void *const end = p + msg->front_alloc_len;
 
     if (CEPH_HAVE_FEATURE(msg->con->peer_features, RESEND_ON_SPLIT)) {
         /* luminous OSD -- encode features and be done */
         p = partial_end;
         ceph_encode_64(&p, msg->con->peer_features);
     } else {
         struct {
             char spgid[CEPH_ENCODING_START_BLK_LEN +
                    CEPH_PGID_ENCODING_LEN + 1];
             __le32 hash;
             __le32 epoch;
             __le32 flags;
             char reqid[CEPH_ENCODING_START_BLK_LEN +
                    sizeof(struct ceph_osd_reqid)];
             char trace[sizeof(struct ceph_blkin_trace_info)];
             __le32 client_inc;
             struct ceph_timespec mtime;
         } __packed head;
         struct ceph_pg pgid;
         void *oloc, *oid, *tail;
         int oloc_len, oid_len, tail_len;
         int len;
 
         /*
          * Pre-luminous OSD -- reencode v8 into v4 using @head
          * as a temporary buffer.  Encode the raw PG; the rest
          * is just a matter of moving oloc, oid and tail blobs
          * around.
          */
         memcpy(&head, p, sizeof(head));
         p += sizeof(head);
 
         oloc = p;
         p += CEPH_ENCODING_START_BLK_LEN;
         pgid.pool = ceph_decode_64(&p);
         p += 4 + 4; /* preferred, key len */
         len = ceph_decode_32(&p);
         p += len;   /* nspace */
         oloc_len = p - oloc;
 
         oid = p;
         len = ceph_decode_32(&p);
         p += len;
         oid_len = p - oid;
 
         tail = p;
         tail_len = partial_end - p;
 
         p = msg->front.iov_base;
         ceph_encode_copy(&p, &head.client_inc, sizeof(head.client_inc));
         ceph_encode_copy(&p, &head.epoch, sizeof(head.epoch));
         ceph_encode_copy(&p, &head.flags, sizeof(head.flags));
         ceph_encode_copy(&p, &head.mtime, sizeof(head.mtime));
 
         /* reassert_version */
         memset(p, 0, sizeof(struct ceph_eversion));
         p += sizeof(struct ceph_eversion);
 
         BUG_ON(p >= oloc);
         memmove(p, oloc, oloc_len);
         p += oloc_len;
 
         pgid.seed = le32_to_cpu(head.hash);
         encode_pgid(&p, &pgid); /* raw pg */
 
         BUG_ON(p >= oid);
         memmove(p, oid, oid_len);
         p += oid_len;
 
         /* tail -- ops, snapid, snapc, retry_attempt */
         BUG_ON(p >= tail);
         memmove(p, tail, tail_len);
         p += tail_len;
 
         msg->hdr.version = cpu_to_le16(4); /* MOSDOp v4 */
     }
 
     BUG_ON(p > end);
     msg->front.iov_len = p - msg->front.iov_base;
     msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 
     dout("%s msg %p tid %llu %u+%u+%u v%d\n", __func__, msg,
          le64_to_cpu(msg->hdr.tid), le32_to_cpu(msg->hdr.front_len),
          le32_to_cpu(msg->hdr.middle_len), le32_to_cpu(msg->hdr.data_len),
          le16_to_cpu(msg->hdr.version));
 }
 
 /*
  * @req has to be assigned a tid and registered.
  */
 static void send_request(struct ceph_osd_request *req)
 {
     struct ceph_osd *osd = req->r_osd;
 
     verify_osd_locked(osd);
     WARN_ON(osd->o_osd != req->r_t.osd);
 
     /* backoff? */
     if (should_plug_request(req))
         return;
 
     /*
      * We may have a previously queued request message hanging
      * around.  Cancel it to avoid corrupting the msgr.
      */
     if (req->r_sent)
         ceph_msg_revoke(req->r_request);
 
     req->r_flags |= CEPH_OSD_FLAG_KNOWN_REDIR;
     if (req->r_attempts)
         req->r_flags |= CEPH_OSD_FLAG_RETRY;
     else
         WARN_ON(req->r_flags & CEPH_OSD_FLAG_RETRY);
 
     encode_request_partial(req, req->r_request);
 
     dout("%s req %p tid %llu to pgid %llu.%x spgid %llu.%xs%d osd%d e%u flags 0x%x attempt %d\n",
          __func__, req, req->r_tid, req->r_t.pgid.pool, req->r_t.pgid.seed,
          req->r_t.spgid.pgid.pool, req->r_t.spgid.pgid.seed,
          req->r_t.spgid.shard, osd->o_osd, req->r_t.epoch, req->r_flags,
          req->r_attempts);
 
     req->r_t.paused = false;
     req->r_stamp = jiffies;
     req->r_attempts++;
 
     req->r_sent = osd->o_incarnation;
     req->r_request->hdr.tid = cpu_to_le64(req->r_tid);
     ceph_con_send(&osd->o_con, ceph_msg_get(req->r_request));
 }
 
 static void maybe_request_map(struct ceph_osd_client *osdc)
 {
     bool continuous = false;
 
     verify_osdc_locked(osdc);
     WARN_ON(!osdc->osdmap->epoch);
 
     if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
         ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD) ||
         ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR)) {
         dout("%s osdc %p continuous\n", __func__, osdc);
         continuous = true;
     } else {
         dout("%s osdc %p onetime\n", __func__, osdc);
     }
 
     if (ceph_monc_want_map(&osdc->client->monc, CEPH_SUB_OSDMAP,
                    osdc->osdmap->epoch + 1, continuous))
         ceph_monc_renew_subs(&osdc->client->monc);
 }
 
 static void complete_request(struct ceph_osd_request *req, int err);
 static void send_map_check(struct ceph_osd_request *req);
 
 static void __submit_request(struct ceph_osd_request *req, bool wrlocked)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     struct ceph_osd *osd;
     enum calc_target_result ct_res;
     int err = 0;
     bool need_send = false;
     bool promoted = false;
 
     WARN_ON(req->r_tid);
     dout("%s req %p wrlocked %d\n", __func__, req, wrlocked);
 
 again:
     ct_res = calc_target(osdc, &req->r_t, false);
     if (ct_res == CALC_TARGET_POOL_DNE && !wrlocked)
         goto promote;
 
     osd = lookup_create_osd(osdc, req->r_t.osd, wrlocked);
     if (IS_ERR(osd)) {
         WARN_ON(PTR_ERR(osd) != -EAGAIN || wrlocked);
         goto promote;
     }
 
     if (osdc->abort_err) {
         dout("req %p abort_err %d\n", req, osdc->abort_err);
         err = osdc->abort_err;
     } else if (osdc->osdmap->epoch < osdc->epoch_barrier) {
         dout("req %p epoch %u barrier %u\n", req, osdc->osdmap->epoch,
              osdc->epoch_barrier);
         req->r_t.paused = true;
         maybe_request_map(osdc);
     } else if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
            ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR)) {
         dout("req %p pausewr\n", req);
         req->r_t.paused = true;
         maybe_request_map(osdc);
     } else if ((req->r_flags & CEPH_OSD_FLAG_READ) &&
            ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD)) {
         dout("req %p pauserd\n", req);
         req->r_t.paused = true;
         maybe_request_map(osdc);
     } else if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
            !(req->r_flags & (CEPH_OSD_FLAG_FULL_TRY |
                      CEPH_OSD_FLAG_FULL_FORCE)) &&
            (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
             pool_full(osdc, req->r_t.base_oloc.pool))) {
         dout("req %p full/pool_full\n", req);
         if (ceph_test_opt(osdc->client, ABORT_ON_FULL)) {
             err = -ENOSPC;
         } else {
             if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL))
                 pr_warn_ratelimited("cluster is full (osdmap FULL)\n");
             else
                 pr_warn_ratelimited("pool %lld is full or reached quota\n",
                             req->r_t.base_oloc.pool);
             req->r_t.paused = true;
             maybe_request_map(osdc);
         }
     } else if (!osd_homeless(osd)) {
         need_send = true;
     } else {
         maybe_request_map(osdc);
     }
 
     mutex_lock(&osd->lock);
     /*
      * Assign the tid atomically with send_request() to protect
      * multiple writes to the same object from racing with each
      * other, resulting in out of order ops on the OSDs.
      */
     req->r_tid = atomic64_inc_return(&osdc->last_tid);
     link_request(osd, req);
     if (need_send)
         send_request(req);
     else if (err)
         complete_request(req, err);
     mutex_unlock(&osd->lock);
 
     if (!err && ct_res == CALC_TARGET_POOL_DNE)
         send_map_check(req);
 
     if (promoted)
         downgrade_write(&osdc->lock);
     return;
 
 promote:
     up_read(&osdc->lock);
     down_write(&osdc->lock);
     wrlocked = true;
     promoted = true;
     goto again;
 }
 
 static void account_request(struct ceph_osd_request *req)
 {
     WARN_ON(req->r_flags & (CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK));
     WARN_ON(!(req->r_flags & (CEPH_OSD_FLAG_READ | CEPH_OSD_FLAG_WRITE)));
 
     req->r_flags |= CEPH_OSD_FLAG_ONDISK;
     atomic_inc(&req->r_osdc->num_requests);
 
     req->r_start_stamp = jiffies;
     req->r_start_latency = ktime_get();
 }
 
 static void submit_request(struct ceph_osd_request *req, bool wrlocked)
 {
     ceph_osdc_get_request(req);
     account_request(req);
     __submit_request(req, wrlocked);
 }
 
 static void finish_request(struct ceph_osd_request *req)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
 
     WARN_ON(lookup_request_mc(&osdc->map_checks, req->r_tid));
     dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
 
     req->r_end_latency = ktime_get();
 
     if (req->r_osd)
         unlink_request(req->r_osd, req);
     atomic_dec(&osdc->num_requests);
 
     /*
      * If an OSD has failed or returned and a request has been sent
      * twice, it's possible to get a reply and end up here while the
      * request message is queued for delivery.  We will ignore the
      * reply, so not a big deal, but better to try and catch it.
      */
     ceph_msg_revoke(req->r_request);
     ceph_msg_revoke_incoming(req->r_reply);
 }
 
 static void __complete_request(struct ceph_osd_request *req)
 {
     dout("%s req %p tid %llu cb %ps result %d\n", __func__, req,
          req->r_tid, req->r_callback, req->r_result);
 
     if (req->r_callback)
         req->r_callback(req);
     complete_all(&req->r_completion);
     ceph_osdc_put_request(req);
 }
 
 static void complete_request_workfn(struct work_struct *work)
 {
     struct ceph_osd_request *req =
         container_of(work, struct ceph_osd_request, r_complete_work);
 
     __complete_request(req);
 }
 
 /*
  * This is open-coded in handle_reply().
  */
 static void complete_request(struct ceph_osd_request *req, int err)
 {
     dout("%s req %p tid %llu err %d\n", __func__, req, req->r_tid, err);
 
     req->r_result = err;
     finish_request(req);
 
     INIT_WORK(&req->r_complete_work, complete_request_workfn);
     queue_work(req->r_osdc->completion_wq, &req->r_complete_work);
 }
 
 static void cancel_map_check(struct ceph_osd_request *req)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     struct ceph_osd_request *lookup_req;
 
     verify_osdc_wrlocked(osdc);
 
     lookup_req = lookup_request_mc(&osdc->map_checks, req->r_tid);
     if (!lookup_req)
         return;
 
     WARN_ON(lookup_req != req);
     erase_request_mc(&osdc->map_checks, req);
     ceph_osdc_put_request(req);
 }
 
 static void cancel_request(struct ceph_osd_request *req)
 {
     dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
 
     cancel_map_check(req);
     finish_request(req);
     complete_all(&req->r_completion);
     ceph_osdc_put_request(req);
 }
 
 static void abort_request(struct ceph_osd_request *req, int err)
 {
     dout("%s req %p tid %llu err %d\n", __func__, req, req->r_tid, err);
 
     cancel_map_check(req);
     complete_request(req, err);
 }
 
 static int abort_fn(struct ceph_osd_request *req, void *arg)
 {
     int err = *(int *)arg;
 
     abort_request(req, err);
     return 0; /* continue iteration */
 }
 
 /*
  * Abort all in-flight requests with @err and arrange for all future
  * requests to be failed immediately.
  */
 void ceph_osdc_abort_requests(struct ceph_osd_client *osdc, int err)
 {
     dout("%s osdc %p err %d\n", __func__, osdc, err);
     down_write(&osdc->lock);
     for_each_request(osdc, abort_fn, &err);
     osdc->abort_err = err;
     up_write(&osdc->lock);
 }
 EXPORT_SYMBOL(ceph_osdc_abort_requests);
 
 void ceph_osdc_clear_abort_err(struct ceph_osd_client *osdc)
 {
     down_write(&osdc->lock);
     osdc->abort_err = 0;
     up_write(&osdc->lock);
 }
 EXPORT_SYMBOL(ceph_osdc_clear_abort_err);
 
 static void update_epoch_barrier(struct ceph_osd_client *osdc, u32 eb)
 {
     if (likely(eb > osdc->epoch_barrier)) {
         dout("updating epoch_barrier from %u to %u\n",
                 osdc->epoch_barrier, eb);
         osdc->epoch_barrier = eb;
         /* Request map if we're not to the barrier yet */
         if (eb > osdc->osdmap->epoch)
             maybe_request_map(osdc);
     }
 }
 
 void ceph_osdc_update_epoch_barrier(struct ceph_osd_client *osdc, u32 eb)
 {
     down_read(&osdc->lock);
     if (unlikely(eb > osdc->epoch_barrier)) {
         up_read(&osdc->lock);
         down_write(&osdc->lock);
         update_epoch_barrier(osdc, eb);
         up_write(&osdc->lock);
     } else {
         up_read(&osdc->lock);
     }
 }
 EXPORT_SYMBOL(ceph_osdc_update_epoch_barrier);
 
 /*
  * We can end up releasing caps as a result of abort_request().
  * In that case, we probably want to ensure that the cap release message
  * has an updated epoch barrier in it, so set the epoch barrier prior to
  * aborting the first request.
  */
 static int abort_on_full_fn(struct ceph_osd_request *req, void *arg)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     bool *victims = arg;
 
     if ((req->r_flags & CEPH_OSD_FLAG_WRITE) &&
         (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
          pool_full(osdc, req->r_t.base_oloc.pool))) {
         if (!*victims) {
             update_epoch_barrier(osdc, osdc->osdmap->epoch);
             *victims = true;
         }
         abort_request(req, -ENOSPC);
     }
 
     return 0; /* continue iteration */
 }
 
 /*
  * Drop all pending requests that are stalled waiting on a full condition to
  * clear, and complete them with ENOSPC as the return code. Set the
  * osdc->epoch_barrier to the latest map epoch that we've seen if any were
  * cancelled.
  */
 static void ceph_osdc_abort_on_full(struct ceph_osd_client *osdc)
 {
     bool victims = false;
 
     if (ceph_test_opt(osdc->client, ABORT_ON_FULL) &&
         (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) || have_pool_full(osdc)))
         for_each_request(osdc, abort_on_full_fn, &victims);
 }
 
 static void check_pool_dne(struct ceph_osd_request *req)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     struct ceph_osdmap *map = osdc->osdmap;
 
     verify_osdc_wrlocked(osdc);
     WARN_ON(!map->epoch);
 
     if (req->r_attempts) {
         /*
          * We sent a request earlier, which means that
          * previously the pool existed, and now it does not
          * (i.e., it was deleted).
          */
         req->r_map_dne_bound = map->epoch;
         dout("%s req %p tid %llu pool disappeared\n", __func__, req,
              req->r_tid);
     } else {
         dout("%s req %p tid %llu map_dne_bound %u have %u\n", __func__,
              req, req->r_tid, req->r_map_dne_bound, map->epoch);
     }
 
     if (req->r_map_dne_bound) {
         if (map->epoch >= req->r_map_dne_bound) {
             /* we had a new enough map */
             pr_info_ratelimited("tid %llu pool does not exist\n",
                         req->r_tid);
             complete_request(req, -ENOENT);
         }
     } else {
         send_map_check(req);
     }
 }
 
 static void map_check_cb(struct ceph_mon_generic_request *greq)
 {
     struct ceph_osd_client *osdc = &greq->monc->client->osdc;
     struct ceph_osd_request *req;
     u64 tid = greq->private_data;
 
     WARN_ON(greq->result || !greq->u.newest);
 
     down_write(&osdc->lock);
     req = lookup_request_mc(&osdc->map_checks, tid);
     if (!req) {
         dout("%s tid %llu dne\n", __func__, tid);
         goto out_unlock;
     }
 
     dout("%s req %p tid %llu map_dne_bound %u newest %llu\n", __func__,
          req, req->r_tid, req->r_map_dne_bound, greq->u.newest);
     if (!req->r_map_dne_bound)
         req->r_map_dne_bound = greq->u.newest;
     erase_request_mc(&osdc->map_checks, req);
     check_pool_dne(req);
 
     ceph_osdc_put_request(req);
 out_unlock:
     up_write(&osdc->lock);
 }
 
 static void send_map_check(struct ceph_osd_request *req)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
     struct ceph_osd_request *lookup_req;
     int ret;
 
     verify_osdc_wrlocked(osdc);
 
     lookup_req = lookup_request_mc(&osdc->map_checks, req->r_tid);
     if (lookup_req) {
         WARN_ON(lookup_req != req);
         return;
     }
 
     ceph_osdc_get_request(req);
     insert_request_mc(&osdc->map_checks, req);
     ret = ceph_monc_get_version_async(&osdc->client->monc, "osdmap",
                       map_check_cb, req->r_tid);
     WARN_ON(ret);
 }
 
 /*
  * lingering requests, watch/notify v2 infrastructure
  */
 static void linger_release(struct kref *kref)
 {
     struct ceph_osd_linger_request *lreq =
         container_of(kref, struct ceph_osd_linger_request, kref);
 
     dout("%s lreq %p reg_req %p ping_req %p\n", __func__, lreq,
          lreq->reg_req, lreq->ping_req);
     WARN_ON(!RB_EMPTY_NODE(&lreq->node));
     WARN_ON(!RB_EMPTY_NODE(&lreq->osdc_node));
     WARN_ON(!RB_EMPTY_NODE(&lreq->mc_node));
     WARN_ON(!list_empty(&lreq->scan_item));
     WARN_ON(!list_empty(&lreq->pending_lworks));
     WARN_ON(lreq->osd);
 
     if (lreq->request_pl)
         ceph_pagelist_release(lreq->request_pl);
     if (lreq->notify_id_pages)
         ceph_release_page_vector(lreq->notify_id_pages, 1);
 
     ceph_osdc_put_request(lreq->reg_req);
     ceph_osdc_put_request(lreq->ping_req);
     target_destroy(&lreq->t);
     kfree(lreq);
 }
 
 static void linger_put(struct ceph_osd_linger_request *lreq)
 {
     if (lreq)
         kref_put(&lreq->kref, linger_release);
 }
 
 static struct ceph_osd_linger_request *
 linger_get(struct ceph_osd_linger_request *lreq)
 {
     kref_get(&lreq->kref);
     return lreq;
 }
 
 static struct ceph_osd_linger_request *
 linger_alloc(struct ceph_osd_client *osdc)
 {
     struct ceph_osd_linger_request *lreq;
 
     lreq = kzalloc(sizeof(*lreq), GFP_NOIO);
     if (!lreq)
         return NULL;
 
     kref_init(&lreq->kref);
     mutex_init(&lreq->lock);
     RB_CLEAR_NODE(&lreq->node);
     RB_CLEAR_NODE(&lreq->osdc_node);
     RB_CLEAR_NODE(&lreq->mc_node);
     INIT_LIST_HEAD(&lreq->scan_item);
     INIT_LIST_HEAD(&lreq->pending_lworks);
     init_completion(&lreq->reg_commit_wait);
     init_completion(&lreq->notify_finish_wait);
 
     lreq->osdc = osdc;
     target_init(&lreq->t);
 
     dout("%s lreq %p\n", __func__, lreq);
     return lreq;
 }
 
 DEFINE_RB_INSDEL_FUNCS(linger, struct ceph_osd_linger_request, linger_id, node)
 DEFINE_RB_FUNCS(linger_osdc, struct ceph_osd_linger_request, linger_id, osdc_node)
 DEFINE_RB_FUNCS(linger_mc, struct ceph_osd_linger_request, linger_id, mc_node)
 
 /*
  * Create linger request <-> OSD session relation.
  *
  * @lreq has to be registered, @osd may be homeless.
  */
 static void link_linger(struct ceph_osd *osd,
             struct ceph_osd_linger_request *lreq)
 {
     verify_osd_locked(osd);
     WARN_ON(!lreq->linger_id || lreq->osd);
     dout("%s osd %p osd%d lreq %p linger_id %llu\n", __func__, osd,
          osd->o_osd, lreq, lreq->linger_id);
 
     if (!osd_homeless(osd))
         __remove_osd_from_lru(osd);
     else
         atomic_inc(&osd->o_osdc->num_homeless);
 
     get_osd(osd);
     insert_linger(&osd->o_linger_requests, lreq);
     lreq->osd = osd;
 }
 
 static void unlink_linger(struct ceph_osd *osd,
               struct ceph_osd_linger_request *lreq)
 {
     verify_osd_locked(osd);
     WARN_ON(lreq->osd != osd);
     dout("%s osd %p osd%d lreq %p linger_id %llu\n", __func__, osd,
          osd->o_osd, lreq, lreq->linger_id);
 
     lreq->osd = NULL;
     erase_linger(&osd->o_linger_requests, lreq);
     put_osd(osd);
 
     if (!osd_homeless(osd))
         maybe_move_osd_to_lru(osd);
     else
         atomic_dec(&osd->o_osdc->num_homeless);
 }
 
 static bool __linger_registered(struct ceph_osd_linger_request *lreq)
 {
     verify_osdc_locked(lreq->osdc);
 
     return !RB_EMPTY_NODE(&lreq->osdc_node);
 }
 
 static bool linger_registered(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     bool registered;
 
     down_read(&osdc->lock);
     registered = __linger_registered(lreq);
     up_read(&osdc->lock);
 
     return registered;
 }
 
 static void linger_register(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
 
     verify_osdc_wrlocked(osdc);
     WARN_ON(lreq->linger_id);
 
     linger_get(lreq);
     lreq->linger_id = ++osdc->last_linger_id;
     insert_linger_osdc(&osdc->linger_requests, lreq);
 }
 
 static void linger_unregister(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
 
     verify_osdc_wrlocked(osdc);
 
     erase_linger_osdc(&osdc->linger_requests, lreq);
     linger_put(lreq);
 }
 
 static void cancel_linger_request(struct ceph_osd_request *req)
 {
     struct ceph_osd_linger_request *lreq = req->r_priv;
 
     WARN_ON(!req->r_linger);
     cancel_request(req);
     linger_put(lreq);
 }
 
 struct linger_work {
     struct work_struct work;
     struct ceph_osd_linger_request *lreq;
     struct list_head pending_item;
     unsigned long queued_stamp;
 
     union {
         struct {
             u64 notify_id;
             u64 notifier_id;
             void *payload; /* points into @msg front */
             size_t payload_len;
 
             struct ceph_msg *msg; /* for ceph_msg_put() */
         } notify;
         struct {
             int err;
         } error;
     };
 };
 
 static struct linger_work *lwork_alloc(struct ceph_osd_linger_request *lreq,
                        work_func_t workfn)
 {
     struct linger_work *lwork;
 
     lwork = kzalloc(sizeof(*lwork), GFP_NOIO);
     if (!lwork)
         return NULL;
 
     INIT_WORK(&lwork->work, workfn);
     INIT_LIST_HEAD(&lwork->pending_item);
     lwork->lreq = linger_get(lreq);
 
     return lwork;
 }
 
 static void lwork_free(struct linger_work *lwork)
 {
     struct ceph_osd_linger_request *lreq = lwork->lreq;
 
     mutex_lock(&lreq->lock);
     list_del(&lwork->pending_item);
     mutex_unlock(&lreq->lock);
 
     linger_put(lreq);
     kfree(lwork);
 }
 
 static void lwork_queue(struct linger_work *lwork)
 {
     struct ceph_osd_linger_request *lreq = lwork->lreq;
     struct ceph_osd_client *osdc = lreq->osdc;
 
     verify_lreq_locked(lreq);
     WARN_ON(!list_empty(&lwork->pending_item));
 
     lwork->queued_stamp = jiffies;
     list_add_tail(&lwork->pending_item, &lreq->pending_lworks);
     queue_work(osdc->notify_wq, &lwork->work);
 }
 
 static void do_watch_notify(struct work_struct *w)
 {
     struct linger_work *lwork = container_of(w, struct linger_work, work);
     struct ceph_osd_linger_request *lreq = lwork->lreq;
 
     if (!linger_registered(lreq)) {
         dout("%s lreq %p not registered\n", __func__, lreq);
         goto out;
     }
 
     WARN_ON(!lreq->is_watch);
     dout("%s lreq %p notify_id %llu notifier_id %llu payload_len %zu\n",
          __func__, lreq, lwork->notify.notify_id, lwork->notify.notifier_id,
          lwork->notify.payload_len);
     lreq->wcb(lreq->data, lwork->notify.notify_id, lreq->linger_id,
           lwork->notify.notifier_id, lwork->notify.payload,
           lwork->notify.payload_len);
 
 out:
     ceph_msg_put(lwork->notify.msg);
     lwork_free(lwork);
 }
 
 static void do_watch_error(struct work_struct *w)
 {
     struct linger_work *lwork = container_of(w, struct linger_work, work);
     struct ceph_osd_linger_request *lreq = lwork->lreq;
 
     if (!linger_registered(lreq)) {
         dout("%s lreq %p not registered\n", __func__, lreq);
         goto out;
     }
 
     dout("%s lreq %p err %d\n", __func__, lreq, lwork->error.err);
     lreq->errcb(lreq->data, lreq->linger_id, lwork->error.err);
 
 out:
     lwork_free(lwork);
 }
 
 static void queue_watch_error(struct ceph_osd_linger_request *lreq)
 {
     struct linger_work *lwork;
 
     lwork = lwork_alloc(lreq, do_watch_error);
     if (!lwork) {
         pr_err("failed to allocate error-lwork\n");
         return;
     }
 
     lwork->error.err = lreq->last_error;
     lwork_queue(lwork);
 }
 
 static void linger_reg_commit_complete(struct ceph_osd_linger_request *lreq,
                        int result)
 {
     if (!completion_done(&lreq->reg_commit_wait)) {
         lreq->reg_commit_error = (result <= 0 ? result : 0);
         complete_all(&lreq->reg_commit_wait);
     }
 }
 
 static void linger_commit_cb(struct ceph_osd_request *req)
 {
     struct ceph_osd_linger_request *lreq = req->r_priv;
 
     mutex_lock(&lreq->lock);
     if (req != lreq->reg_req) {
         dout("%s lreq %p linger_id %llu unknown req (%p != %p)\n",
              __func__, lreq, lreq->linger_id, req, lreq->reg_req);
         goto out;
     }
 
     dout("%s lreq %p linger_id %llu result %d\n", __func__, lreq,
          lreq->linger_id, req->r_result);
     linger_reg_commit_complete(lreq, req->r_result);
     lreq->committed = true;
 
     if (!lreq->is_watch) {
         struct ceph_osd_data *osd_data =
             osd_req_op_data(req, 0, notify, response_data);
         void *p = page_address(osd_data->pages[0]);
 
         WARN_ON(req->r_ops[0].op != CEPH_OSD_OP_NOTIFY ||
             osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
 
         /* make note of the notify_id */
         if (req->r_ops[0].outdata_len >= sizeof(u64)) {
             lreq->notify_id = ceph_decode_64(&p);
             dout("lreq %p notify_id %llu\n", lreq,
                  lreq->notify_id);
         } else {
             dout("lreq %p no notify_id\n", lreq);
         }
     }
 
 out:
     mutex_unlock(&lreq->lock);
     linger_put(lreq);
 }
 
 static int normalize_watch_error(int err)
 {
     /*
      * Translate ENOENT -> ENOTCONN so that a delete->disconnection
      * notification and a failure to reconnect because we raced with
      * the delete appear the same to the user.
      */
     if (err == -ENOENT)
         err = -ENOTCONN;
 
     return err;
 }
 
 static void linger_reconnect_cb(struct ceph_osd_request *req)
 {
     struct ceph_osd_linger_request *lreq = req->r_priv;
 
     mutex_lock(&lreq->lock);
     if (req != lreq->reg_req) {
         dout("%s lreq %p linger_id %llu unknown req (%p != %p)\n",
              __func__, lreq, lreq->linger_id, req, lreq->reg_req);
         goto out;
     }
 
     dout("%s lreq %p linger_id %llu result %d last_error %d\n", __func__,
          lreq, lreq->linger_id, req->r_result, lreq->last_error);
     if (req->r_result < 0) {
         if (!lreq->last_error) {
             lreq->last_error = normalize_watch_error(req->r_result);
             queue_watch_error(lreq);
         }
     }
 
 out:
     mutex_unlock(&lreq->lock);
     linger_put(lreq);
 }
 
 static void send_linger(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osd_request *req;
     int ret;
 
     verify_osdc_wrlocked(osdc);
     mutex_lock(&lreq->lock);
     dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
 
     if (lreq->reg_req) {
         if (lreq->reg_req->r_osd)
             cancel_linger_request(lreq->reg_req);
         ceph_osdc_put_request(lreq->reg_req);
     }
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, true, GFP_NOIO);
     BUG_ON(!req);
 
     target_copy(&req->r_t, &lreq->t);
     req->r_mtime = lreq->mtime;
 
     if (lreq->is_watch && lreq->committed) {
         osd_req_op_watch_init(req, 0, CEPH_OSD_WATCH_OP_RECONNECT,
                       lreq->linger_id, ++lreq->register_gen);
         dout("lreq %p reconnect register_gen %u\n", lreq,
              req->r_ops[0].watch.gen);
         req->r_callback = linger_reconnect_cb;
     } else {
         if (lreq->is_watch) {
             osd_req_op_watch_init(req, 0, CEPH_OSD_WATCH_OP_WATCH,
                           lreq->linger_id, 0);
         } else {
             lreq->notify_id = 0;
 
             refcount_inc(&lreq->request_pl->refcnt);
             osd_req_op_notify_init(req, 0, lreq->linger_id,
                            lreq->request_pl);
             ceph_osd_data_pages_init(
                 osd_req_op_data(req, 0, notify, response_data),
                 lreq->notify_id_pages, PAGE_SIZE, 0, false, false);
         }
         dout("lreq %p register\n", lreq);
         req->r_callback = linger_commit_cb;
     }
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     BUG_ON(ret);
 
     req->r_priv = linger_get(lreq);
     req->r_linger = true;
     lreq->reg_req = req;
     mutex_unlock(&lreq->lock);
 
     submit_request(req, true);
 }
 
 static void linger_ping_cb(struct ceph_osd_request *req)
 {
     struct ceph_osd_linger_request *lreq = req->r_priv;
 
     mutex_lock(&lreq->lock);
     if (req != lreq->ping_req) {
         dout("%s lreq %p linger_id %llu unknown req (%p != %p)\n",
              __func__, lreq, lreq->linger_id, req, lreq->ping_req);
         goto out;
     }
 
     dout("%s lreq %p linger_id %llu result %d ping_sent %lu last_error %d\n",
          __func__, lreq, lreq->linger_id, req->r_result, lreq->ping_sent,
          lreq->last_error);
     if (lreq->register_gen == req->r_ops[0].watch.gen) {
         if (!req->r_result) {
             lreq->watch_valid_thru = lreq->ping_sent;
         } else if (!lreq->last_error) {
             lreq->last_error = normalize_watch_error(req->r_result);
             queue_watch_error(lreq);
         }
     } else {
         dout("lreq %p register_gen %u ignoring old pong %u\n", lreq,
              lreq->register_gen, req->r_ops[0].watch.gen);
     }
 
 out:
     mutex_unlock(&lreq->lock);
     linger_put(lreq);
 }
 
 static void send_linger_ping(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osd_request *req;
     int ret;
 
     if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD)) {
         dout("%s PAUSERD\n", __func__);
         return;
     }
 
     lreq->ping_sent = jiffies;
     dout("%s lreq %p linger_id %llu ping_sent %lu register_gen %u\n",
          __func__, lreq, lreq->linger_id, lreq->ping_sent,
          lreq->register_gen);
 
     if (lreq->ping_req) {
         if (lreq->ping_req->r_osd)
             cancel_linger_request(lreq->ping_req);
         ceph_osdc_put_request(lreq->ping_req);
     }
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, true, GFP_NOIO);
     BUG_ON(!req);
 
     target_copy(&req->r_t, &lreq->t);
     osd_req_op_watch_init(req, 0, CEPH_OSD_WATCH_OP_PING, lreq->linger_id,
                   lreq->register_gen);
     req->r_callback = linger_ping_cb;
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     BUG_ON(ret);
 
     req->r_priv = linger_get(lreq);
     req->r_linger = true;
     lreq->ping_req = req;
 
     ceph_osdc_get_request(req);
     account_request(req);
     req->r_tid = atomic64_inc_return(&osdc->last_tid);
     link_request(lreq->osd, req);
     send_request(req);
 }
 
 static void linger_submit(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osd *osd;
 
     down_write(&osdc->lock);
     linger_register(lreq);
 
     calc_target(osdc, &lreq->t, false);
     osd = lookup_create_osd(osdc, lreq->t.osd, true);
     link_linger(osd, lreq);
 
     send_linger(lreq);
     up_write(&osdc->lock);
 }
 
 static void cancel_linger_map_check(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osd_linger_request *lookup_lreq;
 
     verify_osdc_wrlocked(osdc);
 
     lookup_lreq = lookup_linger_mc(&osdc->linger_map_checks,
                        lreq->linger_id);
     if (!lookup_lreq)
         return;
 
     WARN_ON(lookup_lreq != lreq);
     erase_linger_mc(&osdc->linger_map_checks, lreq);
     linger_put(lreq);
 }
 
 /*
  * @lreq has to be both registered and linked.
  */
 static void __linger_cancel(struct ceph_osd_linger_request *lreq)
 {
     if (lreq->ping_req && lreq->ping_req->r_osd)
         cancel_linger_request(lreq->ping_req);
     if (lreq->reg_req && lreq->reg_req->r_osd)
         cancel_linger_request(lreq->reg_req);
     cancel_linger_map_check(lreq);
     unlink_linger(lreq->osd, lreq);
     linger_unregister(lreq);
 }
 
 static void linger_cancel(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
 
     down_write(&osdc->lock);
     if (__linger_registered(lreq))
         __linger_cancel(lreq);
     up_write(&osdc->lock);
 }
 
 static void send_linger_map_check(struct ceph_osd_linger_request *lreq);
 
 static void check_linger_pool_dne(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osdmap *map = osdc->osdmap;
 
     verify_osdc_wrlocked(osdc);
     WARN_ON(!map->epoch);
 
     if (lreq->register_gen) {
         lreq->map_dne_bound = map->epoch;
         dout("%s lreq %p linger_id %llu pool disappeared\n", __func__,
              lreq, lreq->linger_id);
     } else {
         dout("%s lreq %p linger_id %llu map_dne_bound %u have %u\n",
              __func__, lreq, lreq->linger_id, lreq->map_dne_bound,
              map->epoch);
     }
 
     if (lreq->map_dne_bound) {
         if (map->epoch >= lreq->map_dne_bound) {
             /* we had a new enough map */
             pr_info("linger_id %llu pool does not exist\n",
                 lreq->linger_id);
             linger_reg_commit_complete(lreq, -ENOENT);
             __linger_cancel(lreq);
         }
     } else {
         send_linger_map_check(lreq);
     }
 }
 
 static void linger_map_check_cb(struct ceph_mon_generic_request *greq)
 {
     struct ceph_osd_client *osdc = &greq->monc->client->osdc;
     struct ceph_osd_linger_request *lreq;
     u64 linger_id = greq->private_data;
 
     WARN_ON(greq->result || !greq->u.newest);
 
     down_write(&osdc->lock);
     lreq = lookup_linger_mc(&osdc->linger_map_checks, linger_id);
     if (!lreq) {
         dout("%s linger_id %llu dne\n", __func__, linger_id);
         goto out_unlock;
     }
 
     dout("%s lreq %p linger_id %llu map_dne_bound %u newest %llu\n",
          __func__, lreq, lreq->linger_id, lreq->map_dne_bound,
          greq->u.newest);
     if (!lreq->map_dne_bound)
         lreq->map_dne_bound = greq->u.newest;
     erase_linger_mc(&osdc->linger_map_checks, lreq);
     check_linger_pool_dne(lreq);
 
     linger_put(lreq);
 out_unlock:
     up_write(&osdc->lock);
 }
 
 static void send_linger_map_check(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     struct ceph_osd_linger_request *lookup_lreq;
     int ret;
 
     verify_osdc_wrlocked(osdc);
 
     lookup_lreq = lookup_linger_mc(&osdc->linger_map_checks,
                        lreq->linger_id);
     if (lookup_lreq) {
         WARN_ON(lookup_lreq != lreq);
         return;
     }
 
     linger_get(lreq);
     insert_linger_mc(&osdc->linger_map_checks, lreq);
     ret = ceph_monc_get_version_async(&osdc->client->monc, "osdmap",
                       linger_map_check_cb, lreq->linger_id);
     WARN_ON(ret);
 }
 
 static int linger_reg_commit_wait(struct ceph_osd_linger_request *lreq)
 {
     int ret;
 
     dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
     ret = wait_for_completion_interruptible(&lreq->reg_commit_wait);
     return ret ?: lreq->reg_commit_error;
 }
 
 static int linger_notify_finish_wait(struct ceph_osd_linger_request *lreq)
 {
     int ret;
 
     dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
     ret = wait_for_completion_interruptible(&lreq->notify_finish_wait);
     return ret ?: lreq->notify_finish_error;
 }
 
 /*
  * Timeout callback, called every N seconds.  When 1 or more OSD
  * requests has been active for more than N seconds, we send a keepalive
  * (tag + timestamp) to its OSD to ensure any communications channel
  * reset is detected.
  */
 static void handle_timeout(struct work_struct *work)
 {
     struct ceph_osd_client *osdc =
         container_of(work, struct ceph_osd_client, timeout_work.work);
     struct ceph_options *opts = osdc->client->options;
     unsigned long cutoff = jiffies - opts->osd_keepalive_timeout;
     unsigned long expiry_cutoff = jiffies - opts->osd_request_timeout;
     LIST_HEAD(slow_osds);
     struct rb_node *n, *p;
 
     dout("%s osdc %p\n", __func__, osdc);
     down_write(&osdc->lock);
 
     /*
      * ping osds that are a bit slow.  this ensures that if there
      * is a break in the TCP connection we will notice, and reopen
      * a connection with that osd (from the fault callback).
      */
     for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
         struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
         bool found = false;
 
         for (p = rb_first(&osd->o_requests); p; ) {
             struct ceph_osd_request *req =
                 rb_entry(p, struct ceph_osd_request, r_node);
 
             p = rb_next(p); /* abort_request() */
 
             if (time_before(req->r_stamp, cutoff)) {
                 dout(" req %p tid %llu on osd%d is laggy\n",
                      req, req->r_tid, osd->o_osd);
                 found = true;
             }
             if (opts->osd_request_timeout &&
                 time_before(req->r_start_stamp, expiry_cutoff)) {
                 pr_err_ratelimited("tid %llu on osd%d timeout\n",
                        req->r_tid, osd->o_osd);
                 abort_request(req, -ETIMEDOUT);
             }
         }
         for (p = rb_first(&osd->o_linger_requests); p; p = rb_next(p)) {
             struct ceph_osd_linger_request *lreq =
                 rb_entry(p, struct ceph_osd_linger_request, node);
 
             dout(" lreq %p linger_id %llu is served by osd%d\n",
                  lreq, lreq->linger_id, osd->o_osd);
             found = true;
 
             mutex_lock(&lreq->lock);
             if (lreq->is_watch && lreq->committed && !lreq->last_error)
                 send_linger_ping(lreq);
             mutex_unlock(&lreq->lock);
         }
 
         if (found)
             list_move_tail(&osd->o_keepalive_item, &slow_osds);
     }
 
     if (opts->osd_request_timeout) {
         for (p = rb_first(&osdc->homeless_osd.o_requests); p; ) {
             struct ceph_osd_request *req =
                 rb_entry(p, struct ceph_osd_request, r_node);
 
             p = rb_next(p); /* abort_request() */
 
             if (time_before(req->r_start_stamp, expiry_cutoff)) {
                 pr_err_ratelimited("tid %llu on osd%d timeout\n",
                        req->r_tid, osdc->homeless_osd.o_osd);
                 abort_request(req, -ETIMEDOUT);
             }
         }
     }
 
     if (atomic_read(&osdc->num_homeless) || !list_empty(&slow_osds))
         maybe_request_map(osdc);
 
     while (!list_empty(&slow_osds)) {
         struct ceph_osd *osd = list_first_entry(&slow_osds,
                             struct ceph_osd,
                             o_keepalive_item);
         list_del_init(&osd->o_keepalive_item);
         ceph_con_keepalive(&osd->o_con);
     }
 
     up_write(&osdc->lock);
     schedule_delayed_work(&osdc->timeout_work,
                   osdc->client->options->osd_keepalive_timeout);
 }
 
 static void handle_osds_timeout(struct work_struct *work)
 {
     struct ceph_osd_client *osdc =
         container_of(work, struct ceph_osd_client,
                  osds_timeout_work.work);
     unsigned long delay = osdc->client->options->osd_idle_ttl / 4;
     struct ceph_osd *osd, *nosd;
 
     dout("%s osdc %p\n", __func__, osdc);
     down_write(&osdc->lock);
     list_for_each_entry_safe(osd, nosd, &osdc->osd_lru, o_osd_lru) {
         if (time_before(jiffies, osd->lru_ttl))
             break;
 
         WARN_ON(!RB_EMPTY_ROOT(&osd->o_requests));
         WARN_ON(!RB_EMPTY_ROOT(&osd->o_linger_requests));
         close_osd(osd);
     }
 
     up_write(&osdc->lock);
     schedule_delayed_work(&osdc->osds_timeout_work,
                   round_jiffies_relative(delay));
 }
 
 static int ceph_oloc_decode(void **p, void *end,
                 struct ceph_object_locator *oloc)
 {
     u8 struct_v, struct_cv;
     u32 len;
     void *struct_end;
     int ret = 0;
 
     ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
     struct_v = ceph_decode_8(p);
     struct_cv = ceph_decode_8(p);
     if (struct_v < 3) {
         pr_warn("got v %d < 3 cv %d of ceph_object_locator\n",
             struct_v, struct_cv);
         goto e_inval;
     }
     if (struct_cv > 6) {
         pr_warn("got v %d cv %d > 6 of ceph_object_locator\n",
             struct_v, struct_cv);
         goto e_inval;
     }
     len = ceph_decode_32(p);
     ceph_decode_need(p, end, len, e_inval);
     struct_end = *p + len;
 
     oloc->pool = ceph_decode_64(p);
     *p += 4; /* skip preferred */
 
     len = ceph_decode_32(p);
     if (len > 0) {
         pr_warn("ceph_object_locator::key is set\n");
         goto e_inval;
     }
 
     if (struct_v >= 5) {
         bool changed = false;
 
         len = ceph_decode_32(p);
         if (len > 0) {
             ceph_decode_need(p, end, len, e_inval);
             if (!oloc->pool_ns ||
                 ceph_compare_string(oloc->pool_ns, *p, len))
                 changed = true;
             *p += len;
         } else {
             if (oloc->pool_ns)
                 changed = true;
         }
         if (changed) {
             /* redirect changes namespace */
             pr_warn("ceph_object_locator::nspace is changed\n");
             goto e_inval;
         }
     }
 
     if (struct_v >= 6) {
         s64 hash = ceph_decode_64(p);
         if (hash != -1) {
             pr_warn("ceph_object_locator::hash is set\n");
             goto e_inval;
         }
     }
 
     /* skip the rest */
     *p = struct_end;
 out:
     return ret;
 
 e_inval:
     ret = -EINVAL;
     goto out;
 }
 
 static int ceph_redirect_decode(void **p, void *end,
                 struct ceph_request_redirect *redir)
 {
     u8 struct_v, struct_cv;
     u32 len;
     void *struct_end;
     int ret;
 
     ceph_decode_need(p, end, 1 + 1 + 4, e_inval);
     struct_v = ceph_decode_8(p);
     struct_cv = ceph_decode_8(p);
     if (struct_cv > 1) {
         pr_warn("got v %d cv %d > 1 of ceph_request_redirect\n",
             struct_v, struct_cv);
         goto e_inval;
     }
     len = ceph_decode_32(p);
     ceph_decode_need(p, end, len, e_inval);
     struct_end = *p + len;
 
     ret = ceph_oloc_decode(p, end, &redir->oloc);
     if (ret)
         goto out;
 
     len = ceph_decode_32(p);
     if (len > 0) {
         pr_warn("ceph_request_redirect::object_name is set\n");
         goto e_inval;
     }
 
     /* skip the rest */
     *p = struct_end;
 out:
     return ret;
 
 e_inval:
     ret = -EINVAL;
     goto out;
 }
 
 struct MOSDOpReply {
     struct ceph_pg pgid;
     u64 flags;
     int result;
     u32 epoch;
     int num_ops;
     u32 outdata_len[CEPH_OSD_MAX_OPS];
     s32 rval[CEPH_OSD_MAX_OPS];
     int retry_attempt;
     struct ceph_eversion replay_version;
     u64 user_version;
     struct ceph_request_redirect redirect;
 };
 
 static int decode_MOSDOpReply(const struct ceph_msg *msg, struct MOSDOpReply *m)
 {
     void *p = msg->front.iov_base;
     void *const end = p + msg->front.iov_len;
     u16 version = le16_to_cpu(msg->hdr.version);
     struct ceph_eversion bad_replay_version;
     u8 decode_redir;
     u32 len;
     int ret;
     int i;
 
     ceph_decode_32_safe(&p, end, len, e_inval);
     ceph_decode_need(&p, end, len, e_inval);
     p += len; /* skip oid */
 
     ret = ceph_decode_pgid(&p, end, &m->pgid);
     if (ret)
         return ret;
 
     ceph_decode_64_safe(&p, end, m->flags, e_inval);
     ceph_decode_32_safe(&p, end, m->result, e_inval);
     ceph_decode_need(&p, end, sizeof(bad_replay_version), e_inval);
     memcpy(&bad_replay_version, p, sizeof(bad_replay_version));
     p += sizeof(bad_replay_version);
     ceph_decode_32_safe(&p, end, m->epoch, e_inval);
 
     ceph_decode_32_safe(&p, end, m->num_ops, e_inval);
     if (m->num_ops > ARRAY_SIZE(m->outdata_len))
         goto e_inval;
 
     ceph_decode_need(&p, end, m->num_ops * sizeof(struct ceph_osd_op),
              e_inval);
     for (i = 0; i < m->num_ops; i++) {
         struct ceph_osd_op *op = p;
 
         m->outdata_len[i] = le32_to_cpu(op->payload_len);
         p += sizeof(*op);
     }
 
     ceph_decode_32_safe(&p, end, m->retry_attempt, e_inval);
     for (i = 0; i < m->num_ops; i++)
         ceph_decode_32_safe(&p, end, m->rval[i], e_inval);
 
     if (version >= 5) {
         ceph_decode_need(&p, end, sizeof(m->replay_version), e_inval);
         memcpy(&m->replay_version, p, sizeof(m->replay_version));
         p += sizeof(m->replay_version);
         ceph_decode_64_safe(&p, end, m->user_version, e_inval);
     } else {
         m->replay_version = bad_replay_version; /* struct */
         m->user_version = le64_to_cpu(m->replay_version.version);
     }
 
     if (version >= 6) {
         if (version >= 7)
             ceph_decode_8_safe(&p, end, decode_redir, e_inval);
         else
             decode_redir = 1;
     } else {
         decode_redir = 0;
     }
 
     if (decode_redir) {
         ret = ceph_redirect_decode(&p, end, &m->redirect);
         if (ret)
             return ret;
     } else {
         ceph_oloc_init(&m->redirect.oloc);
     }
 
     return 0;
 
 e_inval:
     return -EINVAL;
 }
 
 /*
  * Handle MOSDOpReply.  Set ->r_result and call the callback if it is
  * specified.
  */
 static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
     struct ceph_osd_request *req;
     struct MOSDOpReply m;
     u64 tid = le64_to_cpu(msg->hdr.tid);
     u32 data_len = 0;
     int ret;
     int i;
 
     dout("%s msg %p tid %llu\n", __func__, msg, tid);
 
     down_read(&osdc->lock);
     if (!osd_registered(osd)) {
         dout("%s osd%d unknown\n", __func__, osd->o_osd);
         goto out_unlock_osdc;
     }
     WARN_ON(osd->o_osd != le64_to_cpu(msg->hdr.src.num));
 
     mutex_lock(&osd->lock);
     req = lookup_request(&osd->o_requests, tid);
     if (!req) {
         dout("%s osd%d tid %llu unknown\n", __func__, osd->o_osd, tid);
         goto out_unlock_session;
     }
 
     m.redirect.oloc.pool_ns = req->r_t.target_oloc.pool_ns;
     ret = decode_MOSDOpReply(msg, &m);
     m.redirect.oloc.pool_ns = NULL;
     if (ret) {
         pr_err("failed to decode MOSDOpReply for tid %llu: %d\n",
                req->r_tid, ret);
         ceph_msg_dump(msg);
         goto fail_request;
     }
     dout("%s req %p tid %llu flags 0x%llx pgid %llu.%x epoch %u attempt %d v %u'%llu uv %llu\n",
          __func__, req, req->r_tid, m.flags, m.pgid.pool, m.pgid.seed,
          m.epoch, m.retry_attempt, le32_to_cpu(m.replay_version.epoch),
          le64_to_cpu(m.replay_version.version), m.user_version);
 
     if (m.retry_attempt >= 0) {
         if (m.retry_attempt != req->r_attempts - 1) {
             dout("req %p tid %llu retry_attempt %d != %d, ignoring\n",
                  req, req->r_tid, m.retry_attempt,
                  req->r_attempts - 1);
             goto out_unlock_session;
         }
     } else {
         WARN_ON(1); /* MOSDOpReply v4 is assumed */
     }
 
     if (!ceph_oloc_empty(&m.redirect.oloc)) {
         dout("req %p tid %llu redirect pool %lld\n", req, req->r_tid,
              m.redirect.oloc.pool);
         unlink_request(osd, req);
         mutex_unlock(&osd->lock);
 
         /*
          * Not ceph_oloc_copy() - changing pool_ns is not
          * supported.
          */
         req->r_t.target_oloc.pool = m.redirect.oloc.pool;
         req->r_flags |= CEPH_OSD_FLAG_REDIRECTED |
                 CEPH_OSD_FLAG_IGNORE_OVERLAY |
                 CEPH_OSD_FLAG_IGNORE_CACHE;
         req->r_tid = 0;
         __submit_request(req, false);
         goto out_unlock_osdc;
     }
 
     if (m.result == -EAGAIN) {
         dout("req %p tid %llu EAGAIN\n", req, req->r_tid);
         unlink_request(osd, req);
         mutex_unlock(&osd->lock);
 
         /*
          * The object is missing on the replica or not (yet)
          * readable.  Clear pgid to force a resend to the primary
          * via legacy_change.
          */
         req->r_t.pgid.pool = 0;
         req->r_t.pgid.seed = 0;
         WARN_ON(!req->r_t.used_replica);
         req->r_flags &= ~(CEPH_OSD_FLAG_BALANCE_READS |
                   CEPH_OSD_FLAG_LOCALIZE_READS);
         req->r_tid = 0;
         __submit_request(req, false);
         goto out_unlock_osdc;
     }
 
     if (m.num_ops != req->r_num_ops) {
         pr_err("num_ops %d != %d for tid %llu\n", m.num_ops,
                req->r_num_ops, req->r_tid);
         goto fail_request;
     }
     for (i = 0; i < req->r_num_ops; i++) {
         dout(" req %p tid %llu op %d rval %d len %u\n", req,
              req->r_tid, i, m.rval[i], m.outdata_len[i]);
         req->r_ops[i].rval = m.rval[i];
         req->r_ops[i].outdata_len = m.outdata_len[i];
         data_len += m.outdata_len[i];
     }
     if (data_len != le32_to_cpu(msg->hdr.data_len)) {
         pr_err("sum of lens %u != %u for tid %llu\n", data_len,
                le32_to_cpu(msg->hdr.data_len), req->r_tid);
         goto fail_request;
     }
     dout("%s req %p tid %llu result %d data_len %u\n", __func__,
          req, req->r_tid, m.result, data_len);
 
     /*
      * Since we only ever request ONDISK, we should only ever get
      * one (type of) reply back.
      */
     WARN_ON(!(m.flags & CEPH_OSD_FLAG_ONDISK));
     req->r_result = m.result ?: data_len;
     finish_request(req);
     mutex_unlock(&osd->lock);
     up_read(&osdc->lock);
 
     __complete_request(req);
     return;
 
 fail_request:
     complete_request(req, -EIO);
 out_unlock_session:
     mutex_unlock(&osd->lock);
 out_unlock_osdc:
     up_read(&osdc->lock);
 }
 
 static void set_pool_was_full(struct ceph_osd_client *osdc)
 {
     struct rb_node *n;
 
     for (n = rb_first(&osdc->osdmap->pg_pools); n; n = rb_next(n)) {
         struct ceph_pg_pool_info *pi =
             rb_entry(n, struct ceph_pg_pool_info, node);
 
         pi->was_full = __pool_full(pi);
     }
 }
 
 static bool pool_cleared_full(struct ceph_osd_client *osdc, s64 pool_id)
 {
     struct ceph_pg_pool_info *pi;
 
     pi = ceph_pg_pool_by_id(osdc->osdmap, pool_id);
     if (!pi)
         return false;
 
     return pi->was_full && !__pool_full(pi);
 }
 
 static enum calc_target_result
 recalc_linger_target(struct ceph_osd_linger_request *lreq)
 {
     struct ceph_osd_client *osdc = lreq->osdc;
     enum calc_target_result ct_res;
 
     ct_res = calc_target(osdc, &lreq->t, true);
     if (ct_res == CALC_TARGET_NEED_RESEND) {
         struct ceph_osd *osd;
 
         osd = lookup_create_osd(osdc, lreq->t.osd, true);
         if (osd != lreq->osd) {
             unlink_linger(lreq->osd, lreq);
             link_linger(osd, lreq);
         }
     }
 
     return ct_res;
 }
 
 /*
  * Requeue requests whose mapping to an OSD has changed.
  */
 static void scan_requests(struct ceph_osd *osd,
               bool force_resend,
               bool cleared_full,
               bool check_pool_cleared_full,
               struct rb_root *need_resend,
               struct list_head *need_resend_linger)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
     struct rb_node *n;
     bool force_resend_writes;
 
     for (n = rb_first(&osd->o_linger_requests); n; ) {
         struct ceph_osd_linger_request *lreq =
             rb_entry(n, struct ceph_osd_linger_request, node);
         enum calc_target_result ct_res;
 
         n = rb_next(n); /* recalc_linger_target() */
 
         dout("%s lreq %p linger_id %llu\n", __func__, lreq,
              lreq->linger_id);
         ct_res = recalc_linger_target(lreq);
         switch (ct_res) {
         case CALC_TARGET_NO_ACTION:
             force_resend_writes = cleared_full ||
                 (check_pool_cleared_full &&
                  pool_cleared_full(osdc, lreq->t.base_oloc.pool));
             if (!force_resend && !force_resend_writes)
                 break;
 
             fallthrough;
         case CALC_TARGET_NEED_RESEND:
             cancel_linger_map_check(lreq);
             /*
              * scan_requests() for the previous epoch(s)
              * may have already added it to the list, since
              * it's not unlinked here.
              */
             if (list_empty(&lreq->scan_item))
                 list_add_tail(&lreq->scan_item, need_resend_linger);
             break;
         case CALC_TARGET_POOL_DNE:
             list_del_init(&lreq->scan_item);
             check_linger_pool_dne(lreq);
             break;
         }
     }
 
     for (n = rb_first(&osd->o_requests); n; ) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
         enum calc_target_result ct_res;
 
         n = rb_next(n); /* unlink_request(), check_pool_dne() */
 
         dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
         ct_res = calc_target(osdc, &req->r_t, false);
         switch (ct_res) {
         case CALC_TARGET_NO_ACTION:
             force_resend_writes = cleared_full ||
                 (check_pool_cleared_full &&
                  pool_cleared_full(osdc, req->r_t.base_oloc.pool));
             if (!force_resend &&
                 (!(req->r_flags & CEPH_OSD_FLAG_WRITE) ||
                  !force_resend_writes))
                 break;
 
             fallthrough;
         case CALC_TARGET_NEED_RESEND:
             cancel_map_check(req);
             unlink_request(osd, req);
             insert_request(need_resend, req);
             break;
         case CALC_TARGET_POOL_DNE:
             check_pool_dne(req);
             break;
         }
     }
 }
 
 static int handle_one_map(struct ceph_osd_client *osdc,
               void *p, void *end, bool incremental,
               struct rb_root *need_resend,
               struct list_head *need_resend_linger)
 {
     struct ceph_osdmap *newmap;
     struct rb_node *n;
     bool skipped_map = false;
     bool was_full;
 
     was_full = ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL);
     set_pool_was_full(osdc);
 
     if (incremental)
         newmap = osdmap_apply_incremental(&p, end,
                           ceph_msgr2(osdc->client),
                           osdc->osdmap);
     else
         newmap = ceph_osdmap_decode(&p, end, ceph_msgr2(osdc->client));
     if (IS_ERR(newmap))
         return PTR_ERR(newmap);
 
     if (newmap != osdc->osdmap) {
         /*
          * Preserve ->was_full before destroying the old map.
          * For pools that weren't in the old map, ->was_full
          * should be false.
          */
         for (n = rb_first(&newmap->pg_pools); n; n = rb_next(n)) {
             struct ceph_pg_pool_info *pi =
                 rb_entry(n, struct ceph_pg_pool_info, node);
             struct ceph_pg_pool_info *old_pi;
 
             old_pi = ceph_pg_pool_by_id(osdc->osdmap, pi->id);
             if (old_pi)
                 pi->was_full = old_pi->was_full;
             else
                 WARN_ON(pi->was_full);
         }
 
         if (osdc->osdmap->epoch &&
             osdc->osdmap->epoch + 1 < newmap->epoch) {
             WARN_ON(incremental);
             skipped_map = true;
         }
 
         ceph_osdmap_destroy(osdc->osdmap);
         osdc->osdmap = newmap;
     }
 
     was_full &= !ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL);
     scan_requests(&osdc->homeless_osd, skipped_map, was_full, true,
               need_resend, need_resend_linger);
 
     for (n = rb_first(&osdc->osds); n; ) {
         struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
 
         n = rb_next(n); /* close_osd() */
 
         scan_requests(osd, skipped_map, was_full, true, need_resend,
                   need_resend_linger);
         if (!ceph_osd_is_up(osdc->osdmap, osd->o_osd) ||
             memcmp(&osd->o_con.peer_addr,
                ceph_osd_addr(osdc->osdmap, osd->o_osd),
                sizeof(struct ceph_entity_addr)))
             close_osd(osd);
     }
 
     return 0;
 }
 
 static void kick_requests(struct ceph_osd_client *osdc,
               struct rb_root *need_resend,
               struct list_head *need_resend_linger)
 {
     struct ceph_osd_linger_request *lreq, *nlreq;
     enum calc_target_result ct_res;
     struct rb_node *n;
 
     /* make sure need_resend targets reflect latest map */
     for (n = rb_first(need_resend); n; ) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
 
         n = rb_next(n);
 
         if (req->r_t.epoch < osdc->osdmap->epoch) {
             ct_res = calc_target(osdc, &req->r_t, false);
             if (ct_res == CALC_TARGET_POOL_DNE) {
                 erase_request(need_resend, req);
                 check_pool_dne(req);
             }
         }
     }
 
     for (n = rb_first(need_resend); n; ) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
         struct ceph_osd *osd;
 
         n = rb_next(n);
         erase_request(need_resend, req); /* before link_request() */
 
         osd = lookup_create_osd(osdc, req->r_t.osd, true);
         link_request(osd, req);
         if (!req->r_linger) {
             if (!osd_homeless(osd) && !req->r_t.paused)
                 send_request(req);
         } else {
             cancel_linger_request(req);
         }
     }
 
     list_for_each_entry_safe(lreq, nlreq, need_resend_linger, scan_item) {
         if (!osd_homeless(lreq->osd))
             send_linger(lreq);
 
         list_del_init(&lreq->scan_item);
     }
 }
 
 /*
  * Process updated osd map.
  *
  * The message contains any number of incremental and full maps, normally
  * indicating some sort of topology change in the cluster.  Kick requests
  * off to different OSDs as needed.
  */
 void ceph_osdc_handle_map(struct ceph_osd_client *osdc, struct ceph_msg *msg)
 {
     void *p = msg->front.iov_base;
     void *const end = p + msg->front.iov_len;
     u32 nr_maps, maplen;
     u32 epoch;
     struct ceph_fsid fsid;
     struct rb_root need_resend = RB_ROOT;
     LIST_HEAD(need_resend_linger);
     bool handled_incremental = false;
     bool was_pauserd, was_pausewr;
     bool pauserd, pausewr;
     int err;
 
     dout("%s have %u\n", __func__, osdc->osdmap->epoch);
     down_write(&osdc->lock);
 
     /* verify fsid */
     ceph_decode_need(&p, end, sizeof(fsid), bad);
     ceph_decode_copy(&p, &fsid, sizeof(fsid));
     if (ceph_check_fsid(osdc->client, &fsid) < 0)
         goto bad;
 
     was_pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
     was_pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
               ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
               have_pool_full(osdc);
 
     /* incremental maps */
     ceph_decode_32_safe(&p, end, nr_maps, bad);
     dout(" %d inc maps\n", nr_maps);
     while (nr_maps > 0) {
         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
         epoch = ceph_decode_32(&p);
         maplen = ceph_decode_32(&p);
         ceph_decode_need(&p, end, maplen, bad);
         if (osdc->osdmap->epoch &&
             osdc->osdmap->epoch + 1 == epoch) {
             dout("applying incremental map %u len %d\n",
                  epoch, maplen);
             err = handle_one_map(osdc, p, p + maplen, true,
                          &need_resend, &need_resend_linger);
             if (err)
                 goto bad;
             handled_incremental = true;
         } else {
             dout("ignoring incremental map %u len %d\n",
                  epoch, maplen);
         }
         p += maplen;
         nr_maps--;
     }
     if (handled_incremental)
         goto done;
 
     /* full maps */
     ceph_decode_32_safe(&p, end, nr_maps, bad);
     dout(" %d full maps\n", nr_maps);
     while (nr_maps) {
         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
         epoch = ceph_decode_32(&p);
         maplen = ceph_decode_32(&p);
         ceph_decode_need(&p, end, maplen, bad);
         if (nr_maps > 1) {
             dout("skipping non-latest full map %u len %d\n",
                  epoch, maplen);
         } else if (osdc->osdmap->epoch >= epoch) {
             dout("skipping full map %u len %d, "
                  "older than our %u\n", epoch, maplen,
                  osdc->osdmap->epoch);
         } else {
             dout("taking full map %u len %d\n", epoch, maplen);
             err = handle_one_map(osdc, p, p + maplen, false,
                          &need_resend, &need_resend_linger);
             if (err)
                 goto bad;
         }
         p += maplen;
         nr_maps--;
     }
 
 done:
     /*
      * subscribe to subsequent osdmap updates if full to ensure
      * we find out when we are no longer full and stop returning
      * ENOSPC.
      */
     pauserd = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSERD);
     pausewr = ceph_osdmap_flag(osdc, CEPH_OSDMAP_PAUSEWR) ||
           ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL) ||
           have_pool_full(osdc);
     if (was_pauserd || was_pausewr || pauserd || pausewr ||
         osdc->osdmap->epoch < osdc->epoch_barrier)
         maybe_request_map(osdc);
 
     kick_requests(osdc, &need_resend, &need_resend_linger);
 
     ceph_osdc_abort_on_full(osdc);
     ceph_monc_got_map(&osdc->client->monc, CEPH_SUB_OSDMAP,
               osdc->osdmap->epoch);
     up_write(&osdc->lock);
     wake_up_all(&osdc->client->auth_wq);
     return;
 
 bad:
     pr_err("osdc handle_map corrupt msg\n");
     ceph_msg_dump(msg);
     up_write(&osdc->lock);
 }
 
 /*
  * Resubmit requests pending on the given osd.
  */
 static void kick_osd_requests(struct ceph_osd *osd)
 {
     struct rb_node *n;
 
     clear_backoffs(osd);
 
     for (n = rb_first(&osd->o_requests); n; ) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
 
         n = rb_next(n); /* cancel_linger_request() */
 
         if (!req->r_linger) {
             if (!req->r_t.paused)
                 send_request(req);
         } else {
             cancel_linger_request(req);
         }
     }
     for (n = rb_first(&osd->o_linger_requests); n; n = rb_next(n)) {
         struct ceph_osd_linger_request *lreq =
             rb_entry(n, struct ceph_osd_linger_request, node);
 
         send_linger(lreq);
     }
 }
 
 /*
  * If the osd connection drops, we need to resubmit all requests.
  */
 static void osd_fault(struct ceph_connection *con)
 {
     struct ceph_osd *osd = con->private;
     struct ceph_osd_client *osdc = osd->o_osdc;
 
     dout("%s osd %p osd%d\n", __func__, osd, osd->o_osd);
 
     down_write(&osdc->lock);
     if (!osd_registered(osd)) {
         dout("%s osd%d unknown\n", __func__, osd->o_osd);
         goto out_unlock;
     }
 
     if (!reopen_osd(osd))
         kick_osd_requests(osd);
     maybe_request_map(osdc);
 
 out_unlock:
     up_write(&osdc->lock);
 }
 
 struct MOSDBackoff {
     struct ceph_spg spgid;
     u32 map_epoch;
     u8 op;
     u64 id;
     struct ceph_hobject_id *begin;
     struct ceph_hobject_id *end;
 };
 
 static int decode_MOSDBackoff(const struct ceph_msg *msg, struct MOSDBackoff *m)
 {
     void *p = msg->front.iov_base;
     void *const end = p + msg->front.iov_len;
     u8 struct_v;
     u32 struct_len;
     int ret;
 
     ret = ceph_start_decoding(&p, end, 1, "spg_t", &struct_v, &struct_len);
     if (ret)
         return ret;
 
     ret = ceph_decode_pgid(&p, end, &m->spgid.pgid);
     if (ret)
         return ret;
 
     ceph_decode_8_safe(&p, end, m->spgid.shard, e_inval);
     ceph_decode_32_safe(&p, end, m->map_epoch, e_inval);
     ceph_decode_8_safe(&p, end, m->op, e_inval);
     ceph_decode_64_safe(&p, end, m->id, e_inval);
 
     m->begin = kzalloc(sizeof(*m->begin), GFP_NOIO);
     if (!m->begin)
         return -ENOMEM;
 
     ret = decode_hoid(&p, end, m->begin);
     if (ret) {
         free_hoid(m->begin);
         return ret;
     }
 
     m->end = kzalloc(sizeof(*m->end), GFP_NOIO);
     if (!m->end) {
         free_hoid(m->begin);
         return -ENOMEM;
     }
 
     ret = decode_hoid(&p, end, m->end);
     if (ret) {
         free_hoid(m->begin);
         free_hoid(m->end);
         return ret;
     }
 
     return 0;
 
 e_inval:
     return -EINVAL;
 }
 
 static struct ceph_msg *create_backoff_message(
                 const struct ceph_osd_backoff *backoff,
                 u32 map_epoch)
 {
     struct ceph_msg *msg;
     void *p, *end;
     int msg_size;
 
     msg_size = CEPH_ENCODING_START_BLK_LEN +
             CEPH_PGID_ENCODING_LEN + 1; /* spgid */
     msg_size += 4 + 1 + 8; /* map_epoch, op, id */
     msg_size += CEPH_ENCODING_START_BLK_LEN +
             hoid_encoding_size(backoff->begin);
     msg_size += CEPH_ENCODING_START_BLK_LEN +
             hoid_encoding_size(backoff->end);
 
     msg = ceph_msg_new(CEPH_MSG_OSD_BACKOFF, msg_size, GFP_NOIO, true);
     if (!msg)
         return NULL;
 
     p = msg->front.iov_base;
     end = p + msg->front_alloc_len;
 
     encode_spgid(&p, &backoff->spgid);
     ceph_encode_32(&p, map_epoch);
     ceph_encode_8(&p, CEPH_OSD_BACKOFF_OP_ACK_BLOCK);
     ceph_encode_64(&p, backoff->id);
     encode_hoid(&p, end, backoff->begin);
     encode_hoid(&p, end, backoff->end);
     BUG_ON(p != end);
 
     msg->front.iov_len = p - msg->front.iov_base;
     msg->hdr.version = cpu_to_le16(1); /* MOSDBackoff v1 */
     msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 
     return msg;
 }
 
 static void handle_backoff_block(struct ceph_osd *osd, struct MOSDBackoff *m)
 {
     struct ceph_spg_mapping *spg;
     struct ceph_osd_backoff *backoff;
     struct ceph_msg *msg;
 
     dout("%s osd%d spgid %llu.%xs%d id %llu\n", __func__, osd->o_osd,
          m->spgid.pgid.pool, m->spgid.pgid.seed, m->spgid.shard, m->id);
 
     spg = lookup_spg_mapping(&osd->o_backoff_mappings, &m->spgid);
     if (!spg) {
         spg = alloc_spg_mapping();
         if (!spg) {
             pr_err("%s failed to allocate spg\n", __func__);
             return;
         }
         spg->spgid = m->spgid; /* struct */
         insert_spg_mapping(&osd->o_backoff_mappings, spg);
     }
 
     backoff = alloc_backoff();
     if (!backoff) {
         pr_err("%s failed to allocate backoff\n", __func__);
         return;
     }
     backoff->spgid = m->spgid; /* struct */
     backoff->id = m->id;
     backoff->begin = m->begin;
     m->begin = NULL; /* backoff now owns this */
     backoff->end = m->end;
     m->end = NULL;   /* ditto */
 
     insert_backoff(&spg->backoffs, backoff);
     insert_backoff_by_id(&osd->o_backoffs_by_id, backoff);
 
     /*
      * Ack with original backoff's epoch so that the OSD can
      * discard this if there was a PG split.
      */
     msg = create_backoff_message(backoff, m->map_epoch);
     if (!msg) {
         pr_err("%s failed to allocate msg\n", __func__);
         return;
     }
     ceph_con_send(&osd->o_con, msg);
 }
 
 static bool target_contained_by(const struct ceph_osd_request_target *t,
                 const struct ceph_hobject_id *begin,
                 const struct ceph_hobject_id *end)
 {
     struct ceph_hobject_id hoid;
     int cmp;
 
     hoid_fill_from_target(&hoid, t);
     cmp = hoid_compare(&hoid, begin);
     return !cmp || (cmp > 0 && hoid_compare(&hoid, end) < 0);
 }
 
 static void handle_backoff_unblock(struct ceph_osd *osd,
                    const struct MOSDBackoff *m)
 {
     struct ceph_spg_mapping *spg;
     struct ceph_osd_backoff *backoff;
     struct rb_node *n;
 
     dout("%s osd%d spgid %llu.%xs%d id %llu\n", __func__, osd->o_osd,
          m->spgid.pgid.pool, m->spgid.pgid.seed, m->spgid.shard, m->id);
 
     backoff = lookup_backoff_by_id(&osd->o_backoffs_by_id, m->id);
     if (!backoff) {
         pr_err("%s osd%d spgid %llu.%xs%d id %llu backoff dne\n",
                __func__, osd->o_osd, m->spgid.pgid.pool,
                m->spgid.pgid.seed, m->spgid.shard, m->id);
         return;
     }
 
     if (hoid_compare(backoff->begin, m->begin) &&
         hoid_compare(backoff->end, m->end)) {
         pr_err("%s osd%d spgid %llu.%xs%d id %llu bad range?\n",
                __func__, osd->o_osd, m->spgid.pgid.pool,
                m->spgid.pgid.seed, m->spgid.shard, m->id);
         /* unblock it anyway... */
     }
 
     spg = lookup_spg_mapping(&osd->o_backoff_mappings, &backoff->spgid);
     BUG_ON(!spg);
 
     erase_backoff(&spg->backoffs, backoff);
     erase_backoff_by_id(&osd->o_backoffs_by_id, backoff);
     free_backoff(backoff);
 
     if (RB_EMPTY_ROOT(&spg->backoffs)) {
         erase_spg_mapping(&osd->o_backoff_mappings, spg);
         free_spg_mapping(spg);
     }
 
     for (n = rb_first(&osd->o_requests); n; n = rb_next(n)) {
         struct ceph_osd_request *req =
             rb_entry(n, struct ceph_osd_request, r_node);
 
         if (!ceph_spg_compare(&req->r_t.spgid, &m->spgid)) {
             /*
              * Match against @m, not @backoff -- the PG may
              * have split on the OSD.
              */
             if (target_contained_by(&req->r_t, m->begin, m->end)) {
                 /*
                  * If no other installed backoff applies,
                  * resend.
                  */
                 send_request(req);
             }
         }
     }
 }
 
 static void handle_backoff(struct ceph_osd *osd, struct ceph_msg *msg)
 {
     struct ceph_osd_client *osdc = osd->o_osdc;
     struct MOSDBackoff m;
     int ret;
 
     down_read(&osdc->lock);
     if (!osd_registered(osd)) {
         dout("%s osd%d unknown\n", __func__, osd->o_osd);
         up_read(&osdc->lock);
         return;
     }
     WARN_ON(osd->o_osd != le64_to_cpu(msg->hdr.src.num));
 
     mutex_lock(&osd->lock);
     ret = decode_MOSDBackoff(msg, &m);
     if (ret) {
         pr_err("failed to decode MOSDBackoff: %d\n", ret);
         ceph_msg_dump(msg);
         goto out_unlock;
     }
 
     switch (m.op) {
     case CEPH_OSD_BACKOFF_OP_BLOCK:
         handle_backoff_block(osd, &m);
         break;
     case CEPH_OSD_BACKOFF_OP_UNBLOCK:
         handle_backoff_unblock(osd, &m);
         break;
     default:
         pr_err("%s osd%d unknown op %d\n", __func__, osd->o_osd, m.op);
     }
 
     free_hoid(m.begin);
     free_hoid(m.end);
 
 out_unlock:
     mutex_unlock(&osd->lock);
     up_read(&osdc->lock);
 }
 
 /*
  * Process osd watch notifications
  */
 static void handle_watch_notify(struct ceph_osd_client *osdc,
                 struct ceph_msg *msg)
 {
     void *p = msg->front.iov_base;
     void *const end = p + msg->front.iov_len;
     struct ceph_osd_linger_request *lreq;
     struct linger_work *lwork;
     u8 proto_ver, opcode;
     u64 cookie, notify_id;
     u64 notifier_id = 0;
     s32 return_code = 0;
     void *payload = NULL;
     u32 payload_len = 0;
 
     ceph_decode_8_safe(&p, end, proto_ver, bad);
     ceph_decode_8_safe(&p, end, opcode, bad);
     ceph_decode_64_safe(&p, end, cookie, bad);
     p += 8; /* skip ver */
     ceph_decode_64_safe(&p, end, notify_id, bad);
 
     if (proto_ver >= 1) {
         ceph_decode_32_safe(&p, end, payload_len, bad);
         ceph_decode_need(&p, end, payload_len, bad);
         payload = p;
         p += payload_len;
     }
 
     if (le16_to_cpu(msg->hdr.version) >= 2)
         ceph_decode_32_safe(&p, end, return_code, bad);
 
     if (le16_to_cpu(msg->hdr.version) >= 3)
         ceph_decode_64_safe(&p, end, notifier_id, bad);
 
     down_read(&osdc->lock);
     lreq = lookup_linger_osdc(&osdc->linger_requests, cookie);
     if (!lreq) {
         dout("%s opcode %d cookie %llu dne\n", __func__, opcode,
              cookie);
         goto out_unlock_osdc;
     }
 
     mutex_lock(&lreq->lock);
     dout("%s opcode %d cookie %llu lreq %p is_watch %d\n", __func__,
          opcode, cookie, lreq, lreq->is_watch);
     if (opcode == CEPH_WATCH_EVENT_DISCONNECT) {
         if (!lreq->last_error) {
             lreq->last_error = -ENOTCONN;
             queue_watch_error(lreq);
         }
     } else if (!lreq->is_watch) {
         /* CEPH_WATCH_EVENT_NOTIFY_COMPLETE */
         if (lreq->notify_id && lreq->notify_id != notify_id) {
             dout("lreq %p notify_id %llu != %llu, ignoring\n", lreq,
                  lreq->notify_id, notify_id);
         } else if (!completion_done(&lreq->notify_finish_wait)) {
             struct ceph_msg_data *data =
                 msg->num_data_items ? &msg->data[0] : NULL;
 
             if (data) {
                 if (lreq->preply_pages) {
                     WARN_ON(data->type !=
                             CEPH_MSG_DATA_PAGES);
                     *lreq->preply_pages = data->pages;
                     *lreq->preply_len = data->length;
                     data->own_pages = false;
                 }
             }
             lreq->notify_finish_error = return_code;
             complete_all(&lreq->notify_finish_wait);
         }
     } else {
         /* CEPH_WATCH_EVENT_NOTIFY */
         lwork = lwork_alloc(lreq, do_watch_notify);
         if (!lwork) {
             pr_err("failed to allocate notify-lwork\n");
             goto out_unlock_lreq;
         }
 
         lwork->notify.notify_id = notify_id;
         lwork->notify.notifier_id = notifier_id;
         lwork->notify.payload = payload;
         lwork->notify.payload_len = payload_len;
         lwork->notify.msg = ceph_msg_get(msg);
         lwork_queue(lwork);
     }
 
 out_unlock_lreq:
     mutex_unlock(&lreq->lock);
 out_unlock_osdc:
     up_read(&osdc->lock);
     return;
 
 bad:
     pr_err("osdc handle_watch_notify corrupt msg\n");
 }
 
 /*
  * Register request, send initial attempt.
  */
 void ceph_osdc_start_request(struct ceph_osd_client *osdc,
                  struct ceph_osd_request *req)
 {
     down_read(&osdc->lock);
     submit_request(req, false);
     up_read(&osdc->lock);
 }
 EXPORT_SYMBOL(ceph_osdc_start_request);
 
 /*
  * Unregister request.  If @req was registered, it isn't completed:
  * r_result isn't set and __complete_request() isn't invoked.
  *
  * If @req wasn't registered, this call may have raced with
  * handle_reply(), in which case r_result would already be set and
  * __complete_request() would be getting invoked, possibly even
  * concurrently with this call.
  */
 void ceph_osdc_cancel_request(struct ceph_osd_request *req)
 {
     struct ceph_osd_client *osdc = req->r_osdc;
 
     down_write(&osdc->lock);
     if (req->r_osd)
         cancel_request(req);
     up_write(&osdc->lock);
 }
 EXPORT_SYMBOL(ceph_osdc_cancel_request);
 
 /*
  * @timeout: in jiffies, 0 means "wait forever"
  */
 static int wait_request_timeout(struct ceph_osd_request *req,
                 unsigned long timeout)
 {
     long left;
 
     dout("%s req %p tid %llu\n", __func__, req, req->r_tid);
     left = wait_for_completion_killable_timeout(&req->r_completion,
                         ceph_timeout_jiffies(timeout));
     if (left <= 0) {
         left = left ?: -ETIMEDOUT;
         ceph_osdc_cancel_request(req);
     } else {
         left = req->r_result; /* completed */
     }
 
     return left;
 }
 
 /*
  * wait for a request to complete
  */
 int ceph_osdc_wait_request(struct ceph_osd_client *osdc,
                struct ceph_osd_request *req)
 {
     return wait_request_timeout(req, 0);
 }
 EXPORT_SYMBOL(ceph_osdc_wait_request);
 
 /*
  * sync - wait for all in-flight requests to flush.  avoid starvation.
  */
 void ceph_osdc_sync(struct ceph_osd_client *osdc)
 {
     struct rb_node *n, *p;
     u64 last_tid = atomic64_read(&osdc->last_tid);
 
 again:
     down_read(&osdc->lock);
     for (n = rb_first(&osdc->osds); n; n = rb_next(n)) {
         struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
 
         mutex_lock(&osd->lock);
         for (p = rb_first(&osd->o_requests); p; p = rb_next(p)) {
             struct ceph_osd_request *req =
                 rb_entry(p, struct ceph_osd_request, r_node);
 
             if (req->r_tid > last_tid)
                 break;
 
             if (!(req->r_flags & CEPH_OSD_FLAG_WRITE))
                 continue;
 
             ceph_osdc_get_request(req);
             mutex_unlock(&osd->lock);
             up_read(&osdc->lock);
             dout("%s waiting on req %p tid %llu last_tid %llu\n",
                  __func__, req, req->r_tid, last_tid);
             wait_for_completion(&req->r_completion);
             ceph_osdc_put_request(req);
             goto again;
         }
 
         mutex_unlock(&osd->lock);
     }
 
     up_read(&osdc->lock);
     dout("%s done last_tid %llu\n", __func__, last_tid);
 }
 EXPORT_SYMBOL(ceph_osdc_sync);
 
 /*
  * Returns a handle, caller owns a ref.
  */
 struct ceph_osd_linger_request *
 ceph_osdc_watch(struct ceph_osd_client *osdc,
         struct ceph_object_id *oid,
         struct ceph_object_locator *oloc,
         rados_watchcb2_t wcb,
         rados_watcherrcb_t errcb,
         void *data)
 {
     struct ceph_osd_linger_request *lreq;
     int ret;
 
     lreq = linger_alloc(osdc);
     if (!lreq)
         return ERR_PTR(-ENOMEM);
 
     lreq->is_watch = true;
     lreq->wcb = wcb;
     lreq->errcb = errcb;
     lreq->data = data;
     lreq->watch_valid_thru = jiffies;
 
     ceph_oid_copy(&lreq->t.base_oid, oid);
     ceph_oloc_copy(&lreq->t.base_oloc, oloc);
     lreq->t.flags = CEPH_OSD_FLAG_WRITE;
     ktime_get_real_ts64(&lreq->mtime);
 
     linger_submit(lreq);
     ret = linger_reg_commit_wait(lreq);
     if (ret) {
         linger_cancel(lreq);
         goto err_put_lreq;
     }
 
     return lreq;
 
 err_put_lreq:
     linger_put(lreq);
     return ERR_PTR(ret);
 }
 EXPORT_SYMBOL(ceph_osdc_watch);
 
 /*
  * Releases a ref.
  *
  * Times out after mount_timeout to preserve rbd unmap behaviour
  * introduced in 2894e1d76974 ("rbd: timeout watch teardown on unmap
  * with mount_timeout").
  */
 int ceph_osdc_unwatch(struct ceph_osd_client *osdc,
               struct ceph_osd_linger_request *lreq)
 {
     struct ceph_options *opts = osdc->client->options;
     struct ceph_osd_request *req;
     int ret;
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
     if (!req)
         return -ENOMEM;
 
     ceph_oid_copy(&req->r_base_oid, &lreq->t.base_oid);
     ceph_oloc_copy(&req->r_base_oloc, &lreq->t.base_oloc);
     req->r_flags = CEPH_OSD_FLAG_WRITE;
     ktime_get_real_ts64(&req->r_mtime);
     osd_req_op_watch_init(req, 0, CEPH_OSD_WATCH_OP_UNWATCH,
                   lreq->linger_id, 0);
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     if (ret)
         goto out_put_req;
 
     ceph_osdc_start_request(osdc, req);
     linger_cancel(lreq);
     linger_put(lreq);
     ret = wait_request_timeout(req, opts->mount_timeout);
 
 out_put_req:
     ceph_osdc_put_request(req);
     return ret;
 }
 EXPORT_SYMBOL(ceph_osdc_unwatch);
 
 static int osd_req_op_notify_ack_init(struct ceph_osd_request *req, int which,
                       u64 notify_id, u64 cookie, void *payload,
                       u32 payload_len)
 {
     struct ceph_osd_req_op *op;
     struct ceph_pagelist *pl;
     int ret;
 
     op = osd_req_op_init(req, which, CEPH_OSD_OP_NOTIFY_ACK, 0);
 
     pl = ceph_pagelist_alloc(GFP_NOIO);
     if (!pl)
         return -ENOMEM;
 
     ret = ceph_pagelist_encode_64(pl, notify_id);
     ret |= ceph_pagelist_encode_64(pl, cookie);
     if (payload) {
         ret |= ceph_pagelist_encode_32(pl, payload_len);
         ret |= ceph_pagelist_append(pl, payload, payload_len);
     } else {
         ret |= ceph_pagelist_encode_32(pl, 0);
     }
     if (ret) {
         ceph_pagelist_release(pl);
         return -ENOMEM;
     }
 
     ceph_osd_data_pagelist_init(&op->notify_ack.request_data, pl);
     op->indata_len = pl->length;
     return 0;
 }
 
 int ceph_osdc_notify_ack(struct ceph_osd_client *osdc,
              struct ceph_object_id *oid,
              struct ceph_object_locator *oloc,
              u64 notify_id,
              u64 cookie,
              void *payload,
              u32 payload_len)
 {
     struct ceph_osd_request *req;
     int ret;
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
     if (!req)
         return -ENOMEM;
 
     ceph_oid_copy(&req->r_base_oid, oid);
     ceph_oloc_copy(&req->r_base_oloc, oloc);
     req->r_flags = CEPH_OSD_FLAG_READ;
 
     ret = osd_req_op_notify_ack_init(req, 0, notify_id, cookie, payload,
                      payload_len);
     if (ret)
         goto out_put_req;
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     if (ret)
         goto out_put_req;
 
     ceph_osdc_start_request(osdc, req);
     ret = ceph_osdc_wait_request(osdc, req);
 
 out_put_req:
     ceph_osdc_put_request(req);
     return ret;
 }
 EXPORT_SYMBOL(ceph_osdc_notify_ack);
 
 /*
  * @timeout: in seconds
  *
  * @preply_{pages,len} are initialized both on success and error.
  * The caller is responsible for:
  *
  *     ceph_release_page_vector(reply_pages, calc_pages_for(0, reply_len))
  */
 int ceph_osdc_notify(struct ceph_osd_client *osdc,
              struct ceph_object_id *oid,
              struct ceph_object_locator *oloc,
              void *payload,
              u32 payload_len,
              u32 timeout,
              struct page ***preply_pages,
              size_t *preply_len)
 {
     struct ceph_osd_linger_request *lreq;
     int ret;
 
     WARN_ON(!timeout);
     if (preply_pages) {
         *preply_pages = NULL;
         *preply_len = 0;
     }
 
     lreq = linger_alloc(osdc);
     if (!lreq)
         return -ENOMEM;
 
     lreq->request_pl = ceph_pagelist_alloc(GFP_NOIO);
     if (!lreq->request_pl) {
         ret = -ENOMEM;
         goto out_put_lreq;
     }
 
     ret = ceph_pagelist_encode_32(lreq->request_pl, 1); /* prot_ver */
     ret |= ceph_pagelist_encode_32(lreq->request_pl, timeout);
     ret |= ceph_pagelist_encode_32(lreq->request_pl, payload_len);
     ret |= ceph_pagelist_append(lreq->request_pl, payload, payload_len);
     if (ret) {
         ret = -ENOMEM;
         goto out_put_lreq;
     }
 
     /* for notify_id */
     lreq->notify_id_pages = ceph_alloc_page_vector(1, GFP_NOIO);
     if (IS_ERR(lreq->notify_id_pages)) {
         ret = PTR_ERR(lreq->notify_id_pages);
         lreq->notify_id_pages = NULL;
         goto out_put_lreq;
     }
 
     lreq->preply_pages = preply_pages;
     lreq->preply_len = preply_len;
 
     ceph_oid_copy(&lreq->t.base_oid, oid);
     ceph_oloc_copy(&lreq->t.base_oloc, oloc);
     lreq->t.flags = CEPH_OSD_FLAG_READ;
 
     linger_submit(lreq);
     ret = linger_reg_commit_wait(lreq);
     if (!ret)
         ret = linger_notify_finish_wait(lreq);
     else
         dout("lreq %p failed to initiate notify %d\n", lreq, ret);
 
     linger_cancel(lreq);
 out_put_lreq:
     linger_put(lreq);
     return ret;
 }
 EXPORT_SYMBOL(ceph_osdc_notify);
 
 /*
  * Return the number of milliseconds since the watch was last
  * confirmed, or an error.  If there is an error, the watch is no
  * longer valid, and should be destroyed with ceph_osdc_unwatch().
  */
 int ceph_osdc_watch_check(struct ceph_osd_client *osdc,
               struct ceph_osd_linger_request *lreq)
 {
     unsigned long stamp, age;
     int ret;
 
     down_read(&osdc->lock);
     mutex_lock(&lreq->lock);
     stamp = lreq->watch_valid_thru;
     if (!list_empty(&lreq->pending_lworks)) {
         struct linger_work *lwork =
             list_first_entry(&lreq->pending_lworks,
                      struct linger_work,
                      pending_item);
 
         if (time_before(lwork->queued_stamp, stamp))
             stamp = lwork->queued_stamp;
     }
     age = jiffies - stamp;
     dout("%s lreq %p linger_id %llu age %lu last_error %d\n", __func__,
          lreq, lreq->linger_id, age, lreq->last_error);
     /* we are truncating to msecs, so return a safe upper bound */
     ret = lreq->last_error ?: 1 + jiffies_to_msecs(age);
 
     mutex_unlock(&lreq->lock);
     up_read(&osdc->lock);
     return ret;
 }
 
 static int decode_watcher(void **p, void *end, struct ceph_watch_item *item)
 {
     u8 struct_v;
     u32 struct_len;
     int ret;
 
     ret = ceph_start_decoding(p, end, 2, "watch_item_t",
                   &struct_v, &struct_len);
     if (ret)
         goto bad;
 
     ret = -EINVAL;
     ceph_decode_copy_safe(p, end, &item->name, sizeof(item->name), bad);
     ceph_decode_64_safe(p, end, item->cookie, bad);
     ceph_decode_skip_32(p, end, bad); /* skip timeout seconds */
 
     if (struct_v >= 2) {
         ret = ceph_decode_entity_addr(p, end, &item->addr);
         if (ret)
             goto bad;
     } else {
         ret = 0;
     }
 
     dout("%s %s%llu cookie %llu addr %s\n", __func__,
          ENTITY_NAME(item->name), item->cookie,
          ceph_pr_addr(&item->addr));
 bad:
     return ret;
 }
 
 static int decode_watchers(void **p, void *end,
                struct ceph_watch_item **watchers,
                u32 *num_watchers)
 {
     u8 struct_v;
     u32 struct_len;
     int i;
     int ret;
 
     ret = ceph_start_decoding(p, end, 1, "obj_list_watch_response_t",
                   &struct_v, &struct_len);
     if (ret)
         return ret;
 
     *num_watchers = ceph_decode_32(p);
     *watchers = kcalloc(*num_watchers, sizeof(**watchers), GFP_NOIO);
     if (!*watchers)
         return -ENOMEM;
 
     for (i = 0; i < *num_watchers; i++) {
         ret = decode_watcher(p, end, *watchers + i);
         if (ret) {
             kfree(*watchers);
             return ret;
         }
     }
 
     return 0;
 }
 
 /*
  * On success, the caller is responsible for:
  *
  *     kfree(watchers);
  */
 int ceph_osdc_list_watchers(struct ceph_osd_client *osdc,
                 struct ceph_object_id *oid,
                 struct ceph_object_locator *oloc,
                 struct ceph_watch_item **watchers,
                 u32 *num_watchers)
 {
     struct ceph_osd_request *req;
     struct page **pages;
     int ret;
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
     if (!req)
         return -ENOMEM;
 
     ceph_oid_copy(&req->r_base_oid, oid);
     ceph_oloc_copy(&req->r_base_oloc, oloc);
     req->r_flags = CEPH_OSD_FLAG_READ;
 
     pages = ceph_alloc_page_vector(1, GFP_NOIO);
     if (IS_ERR(pages)) {
         ret = PTR_ERR(pages);
         goto out_put_req;
     }
 
     osd_req_op_init(req, 0, CEPH_OSD_OP_LIST_WATCHERS, 0);
     ceph_osd_data_pages_init(osd_req_op_data(req, 0, list_watchers,
                          response_data),
                  pages, PAGE_SIZE, 0, false, true);
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     if (ret)
         goto out_put_req;
 
     ceph_osdc_start_request(osdc, req);
     ret = ceph_osdc_wait_request(osdc, req);
     if (ret >= 0) {
         void *p = page_address(pages[0]);
         void *const end = p + req->r_ops[0].outdata_len;
 
         ret = decode_watchers(&p, end, watchers, num_watchers);
     }
 
 out_put_req:
     ceph_osdc_put_request(req);
     return ret;
 }
 EXPORT_SYMBOL(ceph_osdc_list_watchers);
 
 /*
  * Call all pending notify callbacks - for use after a watch is
  * unregistered, to make sure no more callbacks for it will be invoked
  */
 void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc)
 {
     dout("%s osdc %p\n", __func__, osdc);
     flush_workqueue(osdc->notify_wq);
 }
 EXPORT_SYMBOL(ceph_osdc_flush_notifies);
 
 void ceph_osdc_maybe_request_map(struct ceph_osd_client *osdc)
 {
     down_read(&osdc->lock);
     maybe_request_map(osdc);
     up_read(&osdc->lock);
 }
 EXPORT_SYMBOL(ceph_osdc_maybe_request_map);
 
 /*
  * Execute an OSD class method on an object.
  *
  * @flags: CEPH_OSD_FLAG_*
  * @resp_len: in/out param for reply length
  */
 int ceph_osdc_call(struct ceph_osd_client *osdc,
            struct ceph_object_id *oid,
            struct ceph_object_locator *oloc,
            const char *class, const char *method,
            unsigned int flags,
            struct page *req_page, size_t req_len,
            struct page **resp_pages, size_t *resp_len)
 {
     struct ceph_osd_request *req;
     int ret;
 
     if (req_len > PAGE_SIZE)
         return -E2BIG;
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_NOIO);
     if (!req)
         return -ENOMEM;
 
     ceph_oid_copy(&req->r_base_oid, oid);
     ceph_oloc_copy(&req->r_base_oloc, oloc);
     req->r_flags = flags;
 
     ret = osd_req_op_cls_init(req, 0, class, method);
     if (ret)
         goto out_put_req;
 
     if (req_page)
         osd_req_op_cls_request_data_pages(req, 0, &req_page, req_len,
                           0, false, false);
     if (resp_pages)
         osd_req_op_cls_response_data_pages(req, 0, resp_pages,
                            *resp_len, 0, false, false);
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOIO);
     if (ret)
         goto out_put_req;
 
     ceph_osdc_start_request(osdc, req);
     ret = ceph_osdc_wait_request(osdc, req);
     if (ret >= 0) {
         ret = req->r_ops[0].rval;
         if (resp_pages)
             *resp_len = req->r_ops[0].outdata_len;
     }
 
 out_put_req:
     ceph_osdc_put_request(req);
     return ret;
 }
 EXPORT_SYMBOL(ceph_osdc_call);
 
 /*
  * reset all osd connections
  */
 void ceph_osdc_reopen_osds(struct ceph_osd_client *osdc)
 {
     struct rb_node *n;
 
     down_write(&osdc->lock);
     for (n = rb_first(&osdc->osds); n; ) {
         struct ceph_osd *osd = rb_entry(n, struct ceph_osd, o_node);
 
         n = rb_next(n);
         if (!reopen_osd(osd))
             kick_osd_requests(osd);
     }
     up_write(&osdc->lock);
 }
 
 /*
  * init, shutdown
  */
 int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
 {
     int err;
 
     dout("init\n");
     osdc->client = client;
     init_rwsem(&osdc->lock);
     osdc->osds = RB_ROOT;
     INIT_LIST_HEAD(&osdc->osd_lru);
     spin_lock_init(&osdc->osd_lru_lock);
     osd_init(&osdc->homeless_osd);
     osdc->homeless_osd.o_osdc = osdc;
     osdc->homeless_osd.o_osd = CEPH_HOMELESS_OSD;
     osdc->last_linger_id = CEPH_LINGER_ID_START;
     osdc->linger_requests = RB_ROOT;
     osdc->map_checks = RB_ROOT;
     osdc->linger_map_checks = RB_ROOT;
     INIT_DELAYED_WORK(&osdc->timeout_work, handle_timeout);
     INIT_DELAYED_WORK(&osdc->osds_timeout_work, handle_osds_timeout);
 
     err = -ENOMEM;
     osdc->osdmap = ceph_osdmap_alloc();
     if (!osdc->osdmap)
         goto out;
 
     osdc->req_mempool = mempool_create_slab_pool(10,
                              ceph_osd_request_cache);
     if (!osdc->req_mempool)
         goto out_map;
 
     err = ceph_msgpool_init(&osdc->msgpool_op, CEPH_MSG_OSD_OP,
                 PAGE_SIZE, CEPH_OSD_SLAB_OPS, 10, "osd_op");
     if (err < 0)
         goto out_mempool;
     err = ceph_msgpool_init(&osdc->msgpool_op_reply, CEPH_MSG_OSD_OPREPLY,
                 PAGE_SIZE, CEPH_OSD_SLAB_OPS, 10,
                 "osd_op_reply");
     if (err < 0)
         goto out_msgpool;
 
     err = -ENOMEM;
     osdc->notify_wq = create_singlethread_workqueue("ceph-watch-notify");
     if (!osdc->notify_wq)
         goto out_msgpool_reply;
 
     osdc->completion_wq = create_singlethread_workqueue("ceph-completion");
     if (!osdc->completion_wq)
         goto out_notify_wq;
 
     schedule_delayed_work(&osdc->timeout_work,
                   osdc->client->options->osd_keepalive_timeout);
     schedule_delayed_work(&osdc->osds_timeout_work,
         round_jiffies_relative(osdc->client->options->osd_idle_ttl));
 
     return 0;
 
 out_notify_wq:
     destroy_workqueue(osdc->notify_wq);
 out_msgpool_reply:
     ceph_msgpool_destroy(&osdc->msgpool_op_reply);
 out_msgpool:
     ceph_msgpool_destroy(&osdc->msgpool_op);
 out_mempool:
     mempool_destroy(osdc->req_mempool);
 out_map:
     ceph_osdmap_destroy(osdc->osdmap);
 out:
     return err;
 }
 
 void ceph_osdc_stop(struct ceph_osd_client *osdc)
 {
     destroy_workqueue(osdc->completion_wq);
     destroy_workqueue(osdc->notify_wq);
     cancel_delayed_work_sync(&osdc->timeout_work);
     cancel_delayed_work_sync(&osdc->osds_timeout_work);
 
     down_write(&osdc->lock);
     while (!RB_EMPTY_ROOT(&osdc->osds)) {
         struct ceph_osd *osd = rb_entry(rb_first(&osdc->osds),
                         struct ceph_osd, o_node);
         close_osd(osd);
     }
     up_write(&osdc->lock);
     WARN_ON(refcount_read(&osdc->homeless_osd.o_ref) != 1);
     osd_cleanup(&osdc->homeless_osd);
 
     WARN_ON(!list_empty(&osdc->osd_lru));
     WARN_ON(!RB_EMPTY_ROOT(&osdc->linger_requests));
     WARN_ON(!RB_EMPTY_ROOT(&osdc->map_checks));
     WARN_ON(!RB_EMPTY_ROOT(&osdc->linger_map_checks));
     WARN_ON(atomic_read(&osdc->num_requests));
     WARN_ON(atomic_read(&osdc->num_homeless));
 
     ceph_osdmap_destroy(osdc->osdmap);
     mempool_destroy(osdc->req_mempool);
     ceph_msgpool_destroy(&osdc->msgpool_op);
     ceph_msgpool_destroy(&osdc->msgpool_op_reply);
 }
 
 int osd_req_op_copy_from_init(struct ceph_osd_request *req,
                   u64 src_snapid, u64 src_version,
                   struct ceph_object_id *src_oid,
                   struct ceph_object_locator *src_oloc,
                   u32 src_fadvise_flags,
                   u32 dst_fadvise_flags,
                   u32 truncate_seq, u64 truncate_size,
                   u8 copy_from_flags)
 {
     struct ceph_osd_req_op *op;
     struct page **pages;
     void *p, *end;
 
     pages = ceph_alloc_page_vector(1, GFP_KERNEL);
     if (IS_ERR(pages))
         return PTR_ERR(pages);
 
     op = osd_req_op_init(req, 0, CEPH_OSD_OP_COPY_FROM2,
                  dst_fadvise_flags);
     op->copy_from.snapid = src_snapid;
     op->copy_from.src_version = src_version;
     op->copy_from.flags = copy_from_flags;
     op->copy_from.src_fadvise_flags = src_fadvise_flags;
 
     p = page_address(pages[0]);
     end = p + PAGE_SIZE;
     ceph_encode_string(&p, end, src_oid->name, src_oid->name_len);
     encode_oloc(&p, end, src_oloc);
     ceph_encode_32(&p, truncate_seq);
     ceph_encode_64(&p, truncate_size);
     op->indata_len = PAGE_SIZE - (end - p);
 
     ceph_osd_data_pages_init(&op->copy_from.osd_data, pages,
                  op->indata_len, 0, false, true);
     return 0;
 }
 EXPORT_SYMBOL(osd_req_op_copy_from_init);
 
 int __init ceph_osdc_setup(void)
 {
     size_t size = sizeof(struct ceph_osd_request) +
         CEPH_OSD_SLAB_OPS * sizeof(struct ceph_osd_req_op);
 
     BUG_ON(ceph_osd_request_cache);
     ceph_osd_request_cache = kmem_cache_create("ceph_osd_request", size,
                            0, 0, NULL);
 
     return ceph_osd_request_cache ? 0 : -ENOMEM;
 }
 
 void ceph_osdc_cleanup(void)
 {
     BUG_ON(!ceph_osd_request_cache);
     kmem_cache_destroy(ceph_osd_request_cache);
     ceph_osd_request_cache = NULL;
 }
 
 /*
  * handle incoming message
  */
 static void osd_dispatch(struct ceph_connection *con, struct ceph_msg *msg)
 {
     struct ceph_osd *osd = con->private;
     struct ceph_osd_client *osdc = osd->o_osdc;
     int type = le16_to_cpu(msg->hdr.type);
 
     switch (type) {
     case CEPH_MSG_OSD_MAP:
         ceph_osdc_handle_map(osdc, msg);
         break;
     case CEPH_MSG_OSD_OPREPLY:
         handle_reply(osd, msg);
         break;
     case CEPH_MSG_OSD_BACKOFF:
         handle_backoff(osd, msg);
         break;
     case CEPH_MSG_WATCH_NOTIFY:
         handle_watch_notify(osdc, msg);
         break;
 
     default:
         pr_err("received unknown message type %d %s\n", type,
                ceph_msg_type_name(type));
     }
 
     ceph_msg_put(msg);
 }
 
 /*
  * Lookup and return message for incoming reply.  Don't try to do
  * anything about a larger than preallocated data portion of the
  * message at the moment - for now, just skip the message.
  */
 static struct ceph_msg *get_reply(struct ceph_connection *con,
                   struct ceph_msg_header *hdr,
                   int *skip)
 {
     struct ceph_osd *osd = con->private;
     struct ceph_osd_client *osdc = osd->o_osdc;
     struct ceph_msg *m = NULL;
     struct ceph_osd_request *req;
     int front_len = le32_to_cpu(hdr->front_len);
     int data_len = le32_to_cpu(hdr->data_len);
     u64 tid = le64_to_cpu(hdr->tid);
 
     down_read(&osdc->lock);
     if (!osd_registered(osd)) {
         dout("%s osd%d unknown, skipping\n", __func__, osd->o_osd);
         *skip = 1;
         goto out_unlock_osdc;
     }
     WARN_ON(osd->o_osd != le64_to_cpu(hdr->src.num));
 
     mutex_lock(&osd->lock);
     req = lookup_request(&osd->o_requests, tid);
     if (!req) {
         dout("%s osd%d tid %llu unknown, skipping\n", __func__,
              osd->o_osd, tid);
         *skip = 1;
         goto out_unlock_session;
     }
 
     ceph_msg_revoke_incoming(req->r_reply);
 
     if (front_len > req->r_reply->front_alloc_len) {
         pr_warn("%s osd%d tid %llu front %d > preallocated %d\n",
             __func__, osd->o_osd, req->r_tid, front_len,
             req->r_reply->front_alloc_len);
         m = ceph_msg_new(CEPH_MSG_OSD_OPREPLY, front_len, GFP_NOFS,
                  false);
         if (!m)
             goto out_unlock_session;
         ceph_msg_put(req->r_reply);
         req->r_reply = m;
     }
 
     if (data_len > req->r_reply->data_length) {
         pr_warn("%s osd%d tid %llu data %d > preallocated %zu, skipping\n",
             __func__, osd->o_osd, req->r_tid, data_len,
             req->r_reply->data_length);
         m = NULL;
         *skip = 1;
         goto out_unlock_session;
     }
 
     m = ceph_msg_get(req->r_reply);
     dout("get_reply tid %lld %p\n", tid, m);
 
 out_unlock_session:
     mutex_unlock(&osd->lock);
 out_unlock_osdc:
     up_read(&osdc->lock);
     return m;
 }
 
 static struct ceph_msg *alloc_msg_with_page_vector(struct ceph_msg_header *hdr)
 {
     struct ceph_msg *m;
     int type = le16_to_cpu(hdr->type);
     u32 front_len = le32_to_cpu(hdr->front_len);
     u32 data_len = le32_to_cpu(hdr->data_len);
 
     m = ceph_msg_new2(type, front_len, 1, GFP_NOIO, false);
     if (!m)
         return NULL;
 
     if (data_len) {
         struct page **pages;
 
         pages = ceph_alloc_page_vector(calc_pages_for(0, data_len),
                            GFP_NOIO);
         if (IS_ERR(pages)) {
             ceph_msg_put(m);
             return NULL;
         }
 
         ceph_msg_data_add_pages(m, pages, data_len, 0, true);
     }
 
     return m;
 }
 
 static struct ceph_msg *osd_alloc_msg(struct ceph_connection *con,
                       struct ceph_msg_header *hdr,
                       int *skip)
 {
     struct ceph_osd *osd = con->private;
     int type = le16_to_cpu(hdr->type);
 
     *skip = 0;
     switch (type) {
     case CEPH_MSG_OSD_MAP:
     case CEPH_MSG_OSD_BACKOFF:
     case CEPH_MSG_WATCH_NOTIFY:
         return alloc_msg_with_page_vector(hdr);
     case CEPH_MSG_OSD_OPREPLY:
         return get_reply(con, hdr, skip);
     default:
         pr_warn("%s osd%d unknown msg type %d, skipping\n", __func__,
             osd->o_osd, type);
         *skip = 1;
         return NULL;
     }
 }
 
 /*
  * Wrappers to refcount containing ceph_osd struct
  */
 static struct ceph_connection *osd_get_con(struct ceph_connection *con)
 {
     struct ceph_osd *osd = con->private;
     if (get_osd(osd))
         return con;
     return NULL;
 }
 
 static void osd_put_con(struct ceph_connection *con)
 {
     struct ceph_osd *osd = con->private;
     put_osd(osd);
 }
 
 /*
  * authentication
  */
 
 /*
  * Note: returned pointer is the address of a structure that's
  * managed separately.  Caller must *not* attempt to free it.
  */
 static struct ceph_auth_handshake *
 osd_get_authorizer(struct ceph_connection *con, int *proto, int force_new)
 {
     struct ceph_osd *o = con->private;
     struct ceph_osd_client *osdc = o->o_osdc;
     struct ceph_auth_client *ac = osdc->client->monc.auth;
     struct ceph_auth_handshake *auth = &o->o_auth;
     int ret;
 
     ret = __ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_OSD,
                      force_new, proto, NULL, NULL);
     if (ret)
         return ERR_PTR(ret);
 
     return auth;
 }
 
 static int osd_add_authorizer_challenge(struct ceph_connection *con,
                     void *challenge_buf, int challenge_buf_len)
 {
     struct ceph_osd *o = con->private;
     struct ceph_osd_client *osdc = o->o_osdc;
     struct ceph_auth_client *ac = osdc->client->monc.auth;
 
     return ceph_auth_add_authorizer_challenge(ac, o->o_auth.authorizer,
                         challenge_buf, challenge_buf_len);
 }
 
 static int osd_verify_authorizer_reply(struct ceph_connection *con)
 {
     struct ceph_osd *o = con->private;
     struct ceph_osd_client *osdc = o->o_osdc;
     struct ceph_auth_client *ac = osdc->client->monc.auth;
     struct ceph_auth_handshake *auth = &o->o_auth;
 
     return ceph_auth_verify_authorizer_reply(ac, auth->authorizer,
         auth->authorizer_reply_buf, auth->authorizer_reply_buf_len,
         NULL, NULL, NULL, NULL);
 }
 
 static int osd_invalidate_authorizer(struct ceph_connection *con)
 {
     struct ceph_osd *o = con->private;
     struct ceph_osd_client *osdc = o->o_osdc;
     struct ceph_auth_client *ac = osdc->client->monc.auth;
 
     ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_OSD);
     return ceph_monc_validate_auth(&osdc->client->monc);
 }
 
 static int osd_get_auth_request(struct ceph_connection *con,
                 void *buf, int *buf_len,
                 void **authorizer, int *authorizer_len)
 {
     struct ceph_osd *o = con->private;
     struct ceph_auth_client *ac = o->o_osdc->client->monc.auth;
     struct ceph_auth_handshake *auth = &o->o_auth;
     int ret;
 
     ret = ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_OSD,
                        buf, buf_len);
     if (ret)
         return ret;
 
     *authorizer = auth->authorizer_buf;
     *authorizer_len = auth->authorizer_buf_len;
     return 0;
 }
 
 static int osd_handle_auth_reply_more(struct ceph_connection *con,
                       void *reply, int reply_len,
                       void *buf, int *buf_len,
                       void **authorizer, int *authorizer_len)
 {
     struct ceph_osd *o = con->private;
     struct ceph_auth_client *ac = o->o_osdc->client->monc.auth;
     struct ceph_auth_handshake *auth = &o->o_auth;
     int ret;
 
     ret = ceph_auth_handle_svc_reply_more(ac, auth, reply, reply_len,
                           buf, buf_len);
     if (ret)
         return ret;
 
     *authorizer = auth->authorizer_buf;
     *authorizer_len = auth->authorizer_buf_len;
     return 0;
 }
 
 static int osd_handle_auth_done(struct ceph_connection *con,
                 u64 global_id, void *reply, int reply_len,
                 u8 *session_key, int *session_key_len,
                 u8 *con_secret, int *con_secret_len)
 {
     struct ceph_osd *o = con->private;
     struct ceph_auth_client *ac = o->o_osdc->client->monc.auth;
     struct ceph_auth_handshake *auth = &o->o_auth;
 
     return ceph_auth_handle_svc_reply_done(ac, auth, reply, reply_len,
                            session_key, session_key_len,
                            con_secret, con_secret_len);
 }
 
 static int osd_handle_auth_bad_method(struct ceph_connection *con,
                       int used_proto, int result,
                       const int *allowed_protos, int proto_cnt,
                       const int *allowed_modes, int mode_cnt)
 {
     struct ceph_osd *o = con->private;
     struct ceph_mon_client *monc = &o->o_osdc->client->monc;
     int ret;
 
     if (ceph_auth_handle_bad_authorizer(monc->auth, CEPH_ENTITY_TYPE_OSD,
                         used_proto, result,
                         allowed_protos, proto_cnt,
                         allowed_modes, mode_cnt)) {
         ret = ceph_monc_validate_auth(monc);
         if (ret)
             return ret;
     }
 
     return -EACCES;
 }
 
 static void osd_reencode_message(struct ceph_msg *msg)
 {
     int type = le16_to_cpu(msg->hdr.type);
 
     if (type == CEPH_MSG_OSD_OP)
         encode_request_finish(msg);
 }
 
 static int osd_sign_message(struct ceph_msg *msg)
 {
     struct ceph_osd *o = msg->con->private;
     struct ceph_auth_handshake *auth = &o->o_auth;
 
     return ceph_auth_sign_message(auth, msg);
 }
 
 static int osd_check_message_signature(struct ceph_msg *msg)
 {
     struct ceph_osd *o = msg->con->private;
     struct ceph_auth_handshake *auth = &o->o_auth;
 
     return ceph_auth_check_message_signature(auth, msg);
 }
 
 static const struct ceph_connection_operations osd_con_ops = {
     .get = osd_get_con,
     .put = osd_put_con,
     .alloc_msg = osd_alloc_msg,
     .dispatch = osd_dispatch,
     .fault = osd_fault,
     .reencode_message = osd_reencode_message,
     .get_authorizer = osd_get_authorizer,
     .add_authorizer_challenge = osd_add_authorizer_challenge,
     .verify_authorizer_reply = osd_verify_authorizer_reply,
     .invalidate_authorizer = osd_invalidate_authorizer,
     .sign_message = osd_sign_message,
     .check_message_signature = osd_check_message_signature,
     .get_auth_request = osd_get_auth_request,
     .handle_auth_reply_more = osd_handle_auth_reply_more,
     .handle_auth_done = osd_handle_auth_done,
     .handle_auth_bad_method = osd_handle_auth_bad_method,
 };