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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/ceph/striper.h>
 
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/file.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/writeback.h>
 #include <linux/falloc.h>
 #include <linux/iversion.h>
 #include <linux/ktime.h>
 
 #include "super.h"
 #include "mds_client.h"
 #include "cache.h"
 #include "io.h"
 #include "metric.h"
 
 static __le32 ceph_flags_sys2wire(u32 flags)
 {
     u32 wire_flags = 0;
 
     switch (flags & O_ACCMODE) {
     case O_RDONLY:
         wire_flags |= CEPH_O_RDONLY;
         break;
     case O_WRONLY:
         wire_flags |= CEPH_O_WRONLY;
         break;
     case O_RDWR:
         wire_flags |= CEPH_O_RDWR;
         break;
     }
 
     flags &= ~O_ACCMODE;
 
 #define ceph_sys2wire(a) if (flags & a) { wire_flags |= CEPH_##a; flags &= ~a; }
 
     ceph_sys2wire(O_CREAT);
     ceph_sys2wire(O_EXCL);
     ceph_sys2wire(O_TRUNC);
     ceph_sys2wire(O_DIRECTORY);
     ceph_sys2wire(O_NOFOLLOW);
 
 #undef ceph_sys2wire
 
     if (flags)
         dout("unused open flags: %x\n", flags);
 
     return cpu_to_le32(wire_flags);
 }
 
 /*
  * Ceph file operations
  *
  * Implement basic open/close functionality, and implement
  * read/write.
  *
  * We implement three modes of file I/O:
  *  - buffered uses the generic_file_aio_{read,write} helpers
  *
  *  - synchronous is used when there is multi-client read/write
  *    sharing, avoids the page cache, and synchronously waits for an
  *    ack from the OSD.
  *
  *  - direct io takes the variant of the sync path that references
  *    user pages directly.
  *
  * fsync() flushes and waits on dirty pages, but just queues metadata
  * for writeback: since the MDS can recover size and mtime there is no
  * need to wait for MDS acknowledgement.
  */
 
 /*
  * How many pages to get in one call to iov_iter_get_pages().  This
  * determines the size of the on-stack array used as a buffer.
  */
 #define ITER_GET_BVECS_PAGES    64
 
 static ssize_t __iter_get_bvecs(struct iov_iter *iter, size_t maxsize,
                 struct bio_vec *bvecs)
 {
     size_t size = 0;
     int bvec_idx = 0;
 
     if (maxsize > iov_iter_count(iter))
         maxsize = iov_iter_count(iter);
 
     while (size < maxsize) {
         struct page *pages[ITER_GET_BVECS_PAGES];
         ssize_t bytes;
         size_t start;
         int idx = 0;
 
         bytes = iov_iter_get_pages2(iter, pages, maxsize - size,
                        ITER_GET_BVECS_PAGES, &start);
         if (bytes < 0)
             return size ?: bytes;
 
         size += bytes;
 
         for ( ; bytes; idx++, bvec_idx++) {
             struct bio_vec bv = {
                 .bv_page = pages[idx],
                 .bv_len = min_t(int, bytes, PAGE_SIZE - start),
                 .bv_offset = start,
             };
 
             bvecs[bvec_idx] = bv;
             bytes -= bv.bv_len;
             start = 0;
         }
     }
 
     return size;
 }
 
 /*
  * iov_iter_get_pages() only considers one iov_iter segment, no matter
  * what maxsize or maxpages are given.  For ITER_BVEC that is a single
  * page.
  *
  * Attempt to get up to @maxsize bytes worth of pages from @iter.
  * Return the number of bytes in the created bio_vec array, or an error.
  */
 static ssize_t iter_get_bvecs_alloc(struct iov_iter *iter, size_t maxsize,
                     struct bio_vec **bvecs, int *num_bvecs)
 {
     struct bio_vec *bv;
     size_t orig_count = iov_iter_count(iter);
     ssize_t bytes;
     int npages;
 
     iov_iter_truncate(iter, maxsize);
     npages = iov_iter_npages(iter, INT_MAX);
     iov_iter_reexpand(iter, orig_count);
 
     /*
      * __iter_get_bvecs() may populate only part of the array -- zero it
      * out.
      */
     bv = kvmalloc_array(npages, sizeof(*bv), GFP_KERNEL | __GFP_ZERO);
     if (!bv)
         return -ENOMEM;
 
     bytes = __iter_get_bvecs(iter, maxsize, bv);
     if (bytes < 0) {
         /*
          * No pages were pinned -- just free the array.
          */
         kvfree(bv);
         return bytes;
     }
 
     *bvecs = bv;
     *num_bvecs = npages;
     return bytes;
 }
 
 static void put_bvecs(struct bio_vec *bvecs, int num_bvecs, bool should_dirty)
 {
     int i;
 
     for (i = 0; i < num_bvecs; i++) {
         if (bvecs[i].bv_page) {
             if (should_dirty)
                 set_page_dirty_lock(bvecs[i].bv_page);
             put_page(bvecs[i].bv_page);
         }
     }
     kvfree(bvecs);
 }
 
 /*
  * Prepare an open request.  Preallocate ceph_cap to avoid an
  * inopportune ENOMEM later.
  */
 static struct ceph_mds_request *
 prepare_open_request(struct super_block *sb, int flags, int create_mode)
 {
     struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(sb);
     struct ceph_mds_request *req;
     int want_auth = USE_ANY_MDS;
     int op = (flags & O_CREAT) ? CEPH_MDS_OP_CREATE : CEPH_MDS_OP_OPEN;
 
     if (flags & (O_WRONLY|O_RDWR|O_CREAT|O_TRUNC))
         want_auth = USE_AUTH_MDS;
 
     req = ceph_mdsc_create_request(mdsc, op, want_auth);
     if (IS_ERR(req))
         goto out;
     req->r_fmode = ceph_flags_to_mode(flags);
     req->r_args.open.flags = ceph_flags_sys2wire(flags);
     req->r_args.open.mode = cpu_to_le32(create_mode);
 out:
     return req;
 }
 
 static int ceph_init_file_info(struct inode *inode, struct file *file,
                     int fmode, bool isdir)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_mount_options *opt =
         ceph_inode_to_client(&ci->netfs.inode)->mount_options;
     struct ceph_file_info *fi;
     int ret;
 
     dout("%s %p %p 0%o (%s)\n", __func__, inode, file,
             inode->i_mode, isdir ? "dir" : "regular");
     BUG_ON(inode->i_fop->release != ceph_release);
 
     if (isdir) {
         struct ceph_dir_file_info *dfi =
             kmem_cache_zalloc(ceph_dir_file_cachep, GFP_KERNEL);
         if (!dfi)
             return -ENOMEM;
 
         file->private_data = dfi;
         fi = &dfi->file_info;
         dfi->next_offset = 2;
         dfi->readdir_cache_idx = -1;
     } else {
         fi = kmem_cache_zalloc(ceph_file_cachep, GFP_KERNEL);
         if (!fi)
             return -ENOMEM;
 
         if (opt->flags & CEPH_MOUNT_OPT_NOPAGECACHE)
             fi->flags |= CEPH_F_SYNC;
 
         file->private_data = fi;
     }
 
     ceph_get_fmode(ci, fmode, 1);
     fi->fmode = fmode;
 
     spin_lock_init(&fi->rw_contexts_lock);
     INIT_LIST_HEAD(&fi->rw_contexts);
     fi->filp_gen = READ_ONCE(ceph_inode_to_client(inode)->filp_gen);
 
     if ((file->f_mode & FMODE_WRITE) && ceph_has_inline_data(ci)) {
         ret = ceph_uninline_data(file);
         if (ret < 0)
             goto error;
     }
 
     return 0;
 
 error:
     ceph_fscache_unuse_cookie(inode, file->f_mode & FMODE_WRITE);
     ceph_put_fmode(ci, fi->fmode, 1);
     kmem_cache_free(ceph_file_cachep, fi);
     /* wake up anyone waiting for caps on this inode */
     wake_up_all(&ci->i_cap_wq);
     return ret;
 }
 
 /*
  * initialize private struct file data.
  * if we fail, clean up by dropping fmode reference on the ceph_inode
  */
 static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
 {
     int ret = 0;
 
     switch (inode->i_mode & S_IFMT) {
     case S_IFREG:
         ceph_fscache_use_cookie(inode, file->f_mode & FMODE_WRITE);
         fallthrough;
     case S_IFDIR:
         ret = ceph_init_file_info(inode, file, fmode,
                         S_ISDIR(inode->i_mode));
         break;
 
     case S_IFLNK:
         dout("init_file %p %p 0%o (symlink)\n", inode, file,
              inode->i_mode);
         break;
 
     default:
         dout("init_file %p %p 0%o (special)\n", inode, file,
              inode->i_mode);
         /*
          * we need to drop the open ref now, since we don't
          * have .release set to ceph_release.
          */
         BUG_ON(inode->i_fop->release == ceph_release);
 
         /* call the proper open fop */
         ret = inode->i_fop->open(inode, file);
     }
     return ret;
 }
 
 /*
  * try renew caps after session gets killed.
  */
 int ceph_renew_caps(struct inode *inode, int fmode)
 {
     struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_mds_request *req;
     int err, flags, wanted;
 
     spin_lock(&ci->i_ceph_lock);
     __ceph_touch_fmode(ci, mdsc, fmode);
     wanted = __ceph_caps_file_wanted(ci);
     if (__ceph_is_any_real_caps(ci) &&
         (!(wanted & CEPH_CAP_ANY_WR) || ci->i_auth_cap)) {
         int issued = __ceph_caps_issued(ci, NULL);
         spin_unlock(&ci->i_ceph_lock);
         dout("renew caps %p want %s issued %s updating mds_wanted\n",
              inode, ceph_cap_string(wanted), ceph_cap_string(issued));
         ceph_check_caps(ci, 0, NULL);
         return 0;
     }
     spin_unlock(&ci->i_ceph_lock);
 
     flags = 0;
     if ((wanted & CEPH_CAP_FILE_RD) && (wanted & CEPH_CAP_FILE_WR))
         flags = O_RDWR;
     else if (wanted & CEPH_CAP_FILE_RD)
         flags = O_RDONLY;
     else if (wanted & CEPH_CAP_FILE_WR)
         flags = O_WRONLY;
 #ifdef O_LAZY
     if (wanted & CEPH_CAP_FILE_LAZYIO)
         flags |= O_LAZY;
 #endif
 
     req = prepare_open_request(inode->i_sb, flags, 0);
     if (IS_ERR(req)) {
         err = PTR_ERR(req);
         goto out;
     }
 
     req->r_inode = inode;
     ihold(inode);
     req->r_num_caps = 1;
 
     err = ceph_mdsc_do_request(mdsc, NULL, req);
     ceph_mdsc_put_request(req);
 out:
     dout("renew caps %p open result=%d\n", inode, err);
     return err < 0 ? err : 0;
 }
 
 /*
  * If we already have the requisite capabilities, we can satisfy
  * the open request locally (no need to request new caps from the
  * MDS).  We do, however, need to inform the MDS (asynchronously)
  * if our wanted caps set expands.
  */
 int ceph_open(struct inode *inode, struct file *file)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
     struct ceph_mds_client *mdsc = fsc->mdsc;
     struct ceph_mds_request *req;
     struct ceph_file_info *fi = file->private_data;
     int err;
     int flags, fmode, wanted;
 
     if (fi) {
         dout("open file %p is already opened\n", file);
         return 0;
     }
 
     /* filter out O_CREAT|O_EXCL; vfs did that already.  yuck. */
     flags = file->f_flags & ~(O_CREAT|O_EXCL);
     if (S_ISDIR(inode->i_mode))
         flags = O_DIRECTORY;  /* mds likes to know */
 
     dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
          ceph_vinop(inode), file, flags, file->f_flags);
     fmode = ceph_flags_to_mode(flags);
     wanted = ceph_caps_for_mode(fmode);
 
     /* snapped files are read-only */
     if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
         return -EROFS;
 
     /* trivially open snapdir */
     if (ceph_snap(inode) == CEPH_SNAPDIR) {
         return ceph_init_file(inode, file, fmode);
     }
 
     /*
      * No need to block if we have caps on the auth MDS (for
      * write) or any MDS (for read).  Update wanted set
      * asynchronously.
      */
     spin_lock(&ci->i_ceph_lock);
     if (__ceph_is_any_real_caps(ci) &&
         (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
         int mds_wanted = __ceph_caps_mds_wanted(ci, true);
         int issued = __ceph_caps_issued(ci, NULL);
 
         dout("open %p fmode %d want %s issued %s using existing\n",
              inode, fmode, ceph_cap_string(wanted),
              ceph_cap_string(issued));
         __ceph_touch_fmode(ci, mdsc, fmode);
         spin_unlock(&ci->i_ceph_lock);
 
         /* adjust wanted? */
         if ((issued & wanted) != wanted &&
             (mds_wanted & wanted) != wanted &&
             ceph_snap(inode) != CEPH_SNAPDIR)
             ceph_check_caps(ci, 0, NULL);
 
         return ceph_init_file(inode, file, fmode);
     } else if (ceph_snap(inode) != CEPH_NOSNAP &&
            (ci->i_snap_caps & wanted) == wanted) {
         __ceph_touch_fmode(ci, mdsc, fmode);
         spin_unlock(&ci->i_ceph_lock);
         return ceph_init_file(inode, file, fmode);
     }
 
     spin_unlock(&ci->i_ceph_lock);
 
     dout("open fmode %d wants %s\n", fmode, ceph_cap_string(wanted));
     req = prepare_open_request(inode->i_sb, flags, 0);
     if (IS_ERR(req)) {
         err = PTR_ERR(req);
         goto out;
     }
     req->r_inode = inode;
     ihold(inode);
 
     req->r_num_caps = 1;
     err = ceph_mdsc_do_request(mdsc, NULL, req);
     if (!err)
         err = ceph_init_file(inode, file, req->r_fmode);
     ceph_mdsc_put_request(req);
     dout("open result=%d on %llx.%llx\n", err, ceph_vinop(inode));
 out:
     return err;
 }
 
 /* Clone the layout from a synchronous create, if the dir now has Dc caps */
 static void
 cache_file_layout(struct inode *dst, struct inode *src)
 {
     struct ceph_inode_info *cdst = ceph_inode(dst);
     struct ceph_inode_info *csrc = ceph_inode(src);
 
     spin_lock(&cdst->i_ceph_lock);
     if ((__ceph_caps_issued(cdst, NULL) & CEPH_CAP_DIR_CREATE) &&
         !ceph_file_layout_is_valid(&cdst->i_cached_layout)) {
         memcpy(&cdst->i_cached_layout, &csrc->i_layout,
             sizeof(cdst->i_cached_layout));
         rcu_assign_pointer(cdst->i_cached_layout.pool_ns,
                    ceph_try_get_string(csrc->i_layout.pool_ns));
     }
     spin_unlock(&cdst->i_ceph_lock);
 }
 
 /*
  * Try to set up an async create. We need caps, a file layout, and inode number,
  * and either a lease on the dentry or complete dir info. If any of those
  * criteria are not satisfied, then return false and the caller can go
  * synchronous.
  */
 static int try_prep_async_create(struct inode *dir, struct dentry *dentry,
                  struct ceph_file_layout *lo, u64 *pino)
 {
     struct ceph_inode_info *ci = ceph_inode(dir);
     struct ceph_dentry_info *di = ceph_dentry(dentry);
     int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_CREATE;
     u64 ino;
 
     spin_lock(&ci->i_ceph_lock);
     /* No auth cap means no chance for Dc caps */
     if (!ci->i_auth_cap)
         goto no_async;
 
     /* Any delegated inos? */
     if (xa_empty(&ci->i_auth_cap->session->s_delegated_inos))
         goto no_async;
 
     if (!ceph_file_layout_is_valid(&ci->i_cached_layout))
         goto no_async;
 
     if ((__ceph_caps_issued(ci, NULL) & want) != want)
         goto no_async;
 
     if (d_in_lookup(dentry)) {
         if (!__ceph_dir_is_complete(ci))
             goto no_async;
         spin_lock(&dentry->d_lock);
         di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
         spin_unlock(&dentry->d_lock);
     } else if (atomic_read(&ci->i_shared_gen) !=
            READ_ONCE(di->lease_shared_gen)) {
         goto no_async;
     }
 
     ino = ceph_get_deleg_ino(ci->i_auth_cap->session);
     if (!ino)
         goto no_async;
 
     *pino = ino;
     ceph_take_cap_refs(ci, want, false);
     memcpy(lo, &ci->i_cached_layout, sizeof(*lo));
     rcu_assign_pointer(lo->pool_ns,
                ceph_try_get_string(ci->i_cached_layout.pool_ns));
     got = want;
 no_async:
     spin_unlock(&ci->i_ceph_lock);
     return got;
 }
 
 static void restore_deleg_ino(struct inode *dir, u64 ino)
 {
     struct ceph_inode_info *ci = ceph_inode(dir);
     struct ceph_mds_session *s = NULL;
 
     spin_lock(&ci->i_ceph_lock);
     if (ci->i_auth_cap)
         s = ceph_get_mds_session(ci->i_auth_cap->session);
     spin_unlock(&ci->i_ceph_lock);
     if (s) {
         int err = ceph_restore_deleg_ino(s, ino);
         if (err)
             pr_warn("ceph: unable to restore delegated ino 0x%llx to session: %d\n",
                 ino, err);
         ceph_put_mds_session(s);
     }
 }
 
 static void wake_async_create_waiters(struct inode *inode,
                       struct ceph_mds_session *session)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
 
     spin_lock(&ci->i_ceph_lock);
     if (ci->i_ceph_flags & CEPH_I_ASYNC_CREATE) {
         ci->i_ceph_flags &= ~CEPH_I_ASYNC_CREATE;
         wake_up_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT);
     }
     ceph_kick_flushing_inode_caps(session, ci);
     spin_unlock(&ci->i_ceph_lock);
 }
 
 static void ceph_async_create_cb(struct ceph_mds_client *mdsc,
                                  struct ceph_mds_request *req)
 {
     struct dentry *dentry = req->r_dentry;
     struct inode *dinode = d_inode(dentry);
     struct inode *tinode = req->r_target_inode;
     int result = req->r_err ? req->r_err :
             le32_to_cpu(req->r_reply_info.head->result);
 
     WARN_ON_ONCE(dinode && tinode && dinode != tinode);
 
     /* MDS changed -- caller must resubmit */
     if (result == -EJUKEBOX)
         goto out;
 
     mapping_set_error(req->r_parent->i_mapping, result);
 
     if (result) {
         int pathlen = 0;
         u64 base = 0;
         char *path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
                           &base, 0);
 
         pr_warn("async create failure path=(%llx)%s result=%d!\n",
             base, IS_ERR(path) ? "<<bad>>" : path, result);
         ceph_mdsc_free_path(path, pathlen);
 
         ceph_dir_clear_complete(req->r_parent);
         if (!d_unhashed(dentry))
             d_drop(dentry);
 
         if (dinode) {
             mapping_set_error(dinode->i_mapping, result);
             ceph_inode_shutdown(dinode);
             wake_async_create_waiters(dinode, req->r_session);
         }
     }
 
     if (tinode) {
         u64 ino = ceph_vino(tinode).ino;
 
         if (req->r_deleg_ino != ino)
             pr_warn("%s: inode number mismatch! err=%d deleg_ino=0x%llx target=0x%llx\n",
                 __func__, req->r_err, req->r_deleg_ino, ino);
 
         mapping_set_error(tinode->i_mapping, result);
         wake_async_create_waiters(tinode, req->r_session);
     } else if (!result) {
         pr_warn("%s: no req->r_target_inode for 0x%llx\n", __func__,
             req->r_deleg_ino);
     }
 out:
     ceph_mdsc_release_dir_caps(req);
 }
 
 static int ceph_finish_async_create(struct inode *dir, struct dentry *dentry,
                     struct file *file, umode_t mode,
                     struct ceph_mds_request *req,
                     struct ceph_acl_sec_ctx *as_ctx,
                     struct ceph_file_layout *lo)
 {
     int ret;
     char xattr_buf[4];
     struct ceph_mds_reply_inode in = { };
     struct ceph_mds_reply_info_in iinfo = { .in = &in };
     struct ceph_inode_info *ci = ceph_inode(dir);
     struct ceph_dentry_info *di = ceph_dentry(dentry);
     struct inode *inode;
     struct timespec64 now;
     struct ceph_string *pool_ns;
     struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
     struct ceph_vino vino = { .ino = req->r_deleg_ino,
                   .snap = CEPH_NOSNAP };
 
     ktime_get_real_ts64(&now);
 
     inode = ceph_get_inode(dentry->d_sb, vino);
     if (IS_ERR(inode))
         return PTR_ERR(inode);
 
     iinfo.inline_version = CEPH_INLINE_NONE;
     iinfo.change_attr = 1;
     ceph_encode_timespec64(&iinfo.btime, &now);
 
     if (req->r_pagelist) {
         iinfo.xattr_len = req->r_pagelist->length;
         iinfo.xattr_data = req->r_pagelist->mapped_tail;
     } else {
         /* fake it */
         iinfo.xattr_len = ARRAY_SIZE(xattr_buf);
         iinfo.xattr_data = xattr_buf;
         memset(iinfo.xattr_data, 0, iinfo.xattr_len);
     }
 
     in.ino = cpu_to_le64(vino.ino);
     in.snapid = cpu_to_le64(CEPH_NOSNAP);
     in.version = cpu_to_le64(1);    // ???
     in.cap.caps = in.cap.wanted = cpu_to_le32(CEPH_CAP_ALL_FILE);
     in.cap.cap_id = cpu_to_le64(1);
     in.cap.realm = cpu_to_le64(ci->i_snap_realm->ino);
     in.cap.flags = CEPH_CAP_FLAG_AUTH;
     in.ctime = in.mtime = in.atime = iinfo.btime;
     in.truncate_seq = cpu_to_le32(1);
     in.truncate_size = cpu_to_le64(-1ULL);
     in.xattr_version = cpu_to_le64(1);
     in.uid = cpu_to_le32(from_kuid(&init_user_ns, current_fsuid()));
     if (dir->i_mode & S_ISGID) {
         in.gid = cpu_to_le32(from_kgid(&init_user_ns, dir->i_gid));
 
         /* Directories always inherit the setgid bit. */
         if (S_ISDIR(mode))
             mode |= S_ISGID;
     } else {
         in.gid = cpu_to_le32(from_kgid(&init_user_ns, current_fsgid()));
     }
     in.mode = cpu_to_le32((u32)mode);
 
     in.nlink = cpu_to_le32(1);
     in.max_size = cpu_to_le64(lo->stripe_unit);
 
     ceph_file_layout_to_legacy(lo, &in.layout);
     /* lo is private, so pool_ns can't change */
     pool_ns = rcu_dereference_raw(lo->pool_ns);
     if (pool_ns) {
         iinfo.pool_ns_len = pool_ns->len;
         iinfo.pool_ns_data = pool_ns->str;
     }
 
     down_read(&mdsc->snap_rwsem);
     ret = ceph_fill_inode(inode, NULL, &iinfo, NULL, req->r_session,
                   req->r_fmode, NULL);
     up_read(&mdsc->snap_rwsem);
     if (ret) {
         dout("%s failed to fill inode: %d\n", __func__, ret);
         ceph_dir_clear_complete(dir);
         if (!d_unhashed(dentry))
             d_drop(dentry);
         if (inode->i_state & I_NEW)
             discard_new_inode(inode);
     } else {
         struct dentry *dn;
 
         dout("%s d_adding new inode 0x%llx to 0x%llx/%s\n", __func__,
             vino.ino, ceph_ino(dir), dentry->d_name.name);
         ceph_dir_clear_ordered(dir);
         ceph_init_inode_acls(inode, as_ctx);
         if (inode->i_state & I_NEW) {
             /*
              * If it's not I_NEW, then someone created this before
              * we got here. Assume the server is aware of it at
              * that point and don't worry about setting
              * CEPH_I_ASYNC_CREATE.
              */
             ceph_inode(inode)->i_ceph_flags = CEPH_I_ASYNC_CREATE;
             unlock_new_inode(inode);
         }
         if (d_in_lookup(dentry) || d_really_is_negative(dentry)) {
             if (!d_unhashed(dentry))
                 d_drop(dentry);
             dn = d_splice_alias(inode, dentry);
             WARN_ON_ONCE(dn && dn != dentry);
         }
         file->f_mode |= FMODE_CREATED;
         ret = finish_open(file, dentry, ceph_open);
     }
 
     spin_lock(&dentry->d_lock);
     di->flags &= ~CEPH_DENTRY_ASYNC_CREATE;
     wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_CREATE_BIT);
     spin_unlock(&dentry->d_lock);
 
     return ret;
 }
 
 /*
  * Do a lookup + open with a single request.  If we get a non-existent
  * file or symlink, return 1 so the VFS can retry.
  */
 int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
              struct file *file, unsigned flags, umode_t mode)
 {
     struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
     struct ceph_mds_client *mdsc = fsc->mdsc;
     struct ceph_mds_request *req;
     struct dentry *dn;
     struct ceph_acl_sec_ctx as_ctx = {};
     bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
     int mask;
     int err;
 
     dout("atomic_open %p dentry %p '%pd' %s flags %d mode 0%o\n",
          dir, dentry, dentry,
          d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode);
 
     if (dentry->d_name.len > NAME_MAX)
         return -ENAMETOOLONG;
 
     err = ceph_wait_on_conflict_unlink(dentry);
     if (err)
         return err;
     /*
      * Do not truncate the file, since atomic_open is called before the
      * permission check. The caller will do the truncation afterward.
      */
     flags &= ~O_TRUNC;
 
     if (flags & O_CREAT) {
         if (ceph_quota_is_max_files_exceeded(dir))
             return -EDQUOT;
         err = ceph_pre_init_acls(dir, &mode, &as_ctx);
         if (err < 0)
             return err;
         err = ceph_security_init_secctx(dentry, mode, &as_ctx);
         if (err < 0)
             goto out_ctx;
         /* Async create can't handle more than a page of xattrs */
         if (as_ctx.pagelist &&
             !list_is_singular(&as_ctx.pagelist->head))
             try_async = false;
     } else if (!d_in_lookup(dentry)) {
         /* If it's not being looked up, it's negative */
         return -ENOENT;
     }
 retry:
     /* do the open */
     req = prepare_open_request(dir->i_sb, flags, mode);
     if (IS_ERR(req)) {
         err = PTR_ERR(req);
         goto out_ctx;
     }
     req->r_dentry = dget(dentry);
     req->r_num_caps = 2;
     mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
     if (ceph_security_xattr_wanted(dir))
         mask |= CEPH_CAP_XATTR_SHARED;
     req->r_args.open.mask = cpu_to_le32(mask);
     req->r_parent = dir;
     ihold(dir);
 
     if (flags & O_CREAT) {
         struct ceph_file_layout lo;
 
         req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
         req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
         if (as_ctx.pagelist) {
             req->r_pagelist = as_ctx.pagelist;
             as_ctx.pagelist = NULL;
         }
         if (try_async &&
             (req->r_dir_caps =
               try_prep_async_create(dir, dentry, &lo,
                         &req->r_deleg_ino))) {
             struct ceph_dentry_info *di = ceph_dentry(dentry);
 
             set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
             req->r_args.open.flags |= cpu_to_le32(CEPH_O_EXCL);
             req->r_callback = ceph_async_create_cb;
 
             spin_lock(&dentry->d_lock);
             di->flags |= CEPH_DENTRY_ASYNC_CREATE;
             spin_unlock(&dentry->d_lock);
 
             err = ceph_mdsc_submit_request(mdsc, dir, req);
             if (!err) {
                 err = ceph_finish_async_create(dir, dentry,
                             file, mode, req,
                             &as_ctx, &lo);
             } else if (err == -EJUKEBOX) {
                 restore_deleg_ino(dir, req->r_deleg_ino);
                 ceph_mdsc_put_request(req);
                 try_async = false;
                 ceph_put_string(rcu_dereference_raw(lo.pool_ns));
                 goto retry;
             }
             ceph_put_string(rcu_dereference_raw(lo.pool_ns));
             goto out_req;
         }
     }
 
     set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
     err = ceph_mdsc_do_request(mdsc, (flags & O_CREAT) ? dir : NULL, req);
     if (err == -ENOENT) {
         dentry = ceph_handle_snapdir(req, dentry);
         if (IS_ERR(dentry)) {
             err = PTR_ERR(dentry);
             goto out_req;
         }
         err = 0;
     }
 
     if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
         err = ceph_handle_notrace_create(dir, dentry);
 
     if (d_in_lookup(dentry)) {
         dn = ceph_finish_lookup(req, dentry, err);
         if (IS_ERR(dn))
             err = PTR_ERR(dn);
     } else {
         /* we were given a hashed negative dentry */
         dn = NULL;
     }
     if (err)
         goto out_req;
     if (dn || d_really_is_negative(dentry) || d_is_symlink(dentry)) {
         /* make vfs retry on splice, ENOENT, or symlink */
         dout("atomic_open finish_no_open on dn %p\n", dn);
         err = finish_no_open(file, dn);
     } else {
         dout("atomic_open finish_open on dn %p\n", dn);
         if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
             struct inode *newino = d_inode(dentry);
 
             cache_file_layout(dir, newino);
             ceph_init_inode_acls(newino, &as_ctx);
             file->f_mode |= FMODE_CREATED;
         }
         err = finish_open(file, dentry, ceph_open);
     }
 out_req:
     ceph_mdsc_put_request(req);
 out_ctx:
     ceph_release_acl_sec_ctx(&as_ctx);
     dout("atomic_open result=%d\n", err);
     return err;
 }
 
 int ceph_release(struct inode *inode, struct file *file)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
 
     if (S_ISDIR(inode->i_mode)) {
         struct ceph_dir_file_info *dfi = file->private_data;
         dout("release inode %p dir file %p\n", inode, file);
         WARN_ON(!list_empty(&dfi->file_info.rw_contexts));
 
         ceph_put_fmode(ci, dfi->file_info.fmode, 1);
 
         if (dfi->last_readdir)
             ceph_mdsc_put_request(dfi->last_readdir);
         kfree(dfi->last_name);
         kfree(dfi->dir_info);
         kmem_cache_free(ceph_dir_file_cachep, dfi);
     } else {
         struct ceph_file_info *fi = file->private_data;
         dout("release inode %p regular file %p\n", inode, file);
         WARN_ON(!list_empty(&fi->rw_contexts));
 
         ceph_fscache_unuse_cookie(inode, file->f_mode & FMODE_WRITE);
         ceph_put_fmode(ci, fi->fmode, 1);
 
         kmem_cache_free(ceph_file_cachep, fi);
     }
 
     /* wake up anyone waiting for caps on this inode */
     wake_up_all(&ci->i_cap_wq);
     return 0;
 }
 
 enum {
     HAVE_RETRIED = 1,
     CHECK_EOF =    2,
     READ_INLINE =  3,
 };
 
 /*
  * Completely synchronous read and write methods.  Direct from __user
  * buffer to osd, or directly to user pages (if O_DIRECT).
  *
  * If the read spans object boundary, just do multiple reads.  (That's not
  * atomic, but good enough for now.)
  *
  * If we get a short result from the OSD, check against i_size; we need to
  * only return a short read to the caller if we hit EOF.
  */
 static ssize_t ceph_sync_read(struct kiocb *iocb, struct iov_iter *to,
                   int *retry_op)
 {
     struct file *file = iocb->ki_filp;
     struct inode *inode = file_inode(file);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
     struct ceph_osd_client *osdc = &fsc->client->osdc;
     ssize_t ret;
     u64 off = iocb->ki_pos;
     u64 len = iov_iter_count(to);
     u64 i_size = i_size_read(inode);
 
     dout("sync_read on file %p %llu~%u %s\n", file, off, (unsigned)len,
          (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
 
     if (!len)
         return 0;
     /*
      * flush any page cache pages in this range.  this
      * will make concurrent normal and sync io slow,
      * but it will at least behave sensibly when they are
      * in sequence.
      */
     ret = filemap_write_and_wait_range(inode->i_mapping,
                        off, off + len - 1);
     if (ret < 0)
         return ret;
 
     ret = 0;
     while ((len = iov_iter_count(to)) > 0) {
         struct ceph_osd_request *req;
         struct page **pages;
         int num_pages;
         size_t page_off;
         bool more;
         int idx;
         size_t left;
 
         req = ceph_osdc_new_request(osdc, &ci->i_layout,
                     ci->i_vino, off, &len, 0, 1,
                     CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
                     NULL, ci->i_truncate_seq,
                     ci->i_truncate_size, false);
         if (IS_ERR(req)) {
             ret = PTR_ERR(req);
             break;
         }
 
         more = len < iov_iter_count(to);
 
         num_pages = calc_pages_for(off, len);
         page_off = off & ~PAGE_MASK;
         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
         if (IS_ERR(pages)) {
             ceph_osdc_put_request(req);
             ret = PTR_ERR(pages);
             break;
         }
 
         osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_off,
                          false, false);
         ceph_osdc_start_request(osdc, req);
         ret = ceph_osdc_wait_request(osdc, req);
 
         ceph_update_read_metrics(&fsc->mdsc->metric,
                      req->r_start_latency,
                      req->r_end_latency,
                      len, ret);
 
         ceph_osdc_put_request(req);
 
         i_size = i_size_read(inode);
         dout("sync_read %llu~%llu got %zd i_size %llu%s\n",
              off, len, ret, i_size, (more ? " MORE" : ""));
 
         if (ret == -ENOENT)
             ret = 0;
         if (ret >= 0 && ret < len && (off + ret < i_size)) {
             int zlen = min(len - ret, i_size - off - ret);
             int zoff = page_off + ret;
             dout("sync_read zero gap %llu~%llu\n",
                              off + ret, off + ret + zlen);
             ceph_zero_page_vector_range(zoff, zlen, pages);
             ret += zlen;
         }
 
         idx = 0;
         left = ret > 0 ? ret : 0;
         while (left > 0) {
             size_t len, copied;
             page_off = off & ~PAGE_MASK;
             len = min_t(size_t, left, PAGE_SIZE - page_off);
             SetPageUptodate(pages[idx]);
             copied = copy_page_to_iter(pages[idx++],
                            page_off, len, to);
             off += copied;
             left -= copied;
             if (copied < len) {
                 ret = -EFAULT;
                 break;
             }
         }
         ceph_release_page_vector(pages, num_pages);
 
         if (ret < 0) {
             if (ret == -EBLOCKLISTED)
                 fsc->blocklisted = true;
             break;
         }
 
         if (off >= i_size || !more)
             break;
     }
 
     if (off > iocb->ki_pos) {
         if (off >= i_size) {
             *retry_op = CHECK_EOF;
             ret = i_size - iocb->ki_pos;
             iocb->ki_pos = i_size;
         } else {
             ret = off - iocb->ki_pos;
             iocb->ki_pos = off;
         }
     }
 
     dout("sync_read result %zd retry_op %d\n", ret, *retry_op);
     return ret;
 }
 
 struct ceph_aio_request {
     struct kiocb *iocb;
     size_t total_len;
     bool write;
     bool should_dirty;
     int error;
     struct list_head osd_reqs;
     unsigned num_reqs;
     atomic_t pending_reqs;
     struct timespec64 mtime;
     struct ceph_cap_flush *prealloc_cf;
 };
 
 struct ceph_aio_work {
     struct work_struct work;
     struct ceph_osd_request *req;
 };
 
 static void ceph_aio_retry_work(struct work_struct *work);
 
 static void ceph_aio_complete(struct inode *inode,
                   struct ceph_aio_request *aio_req)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
     int ret;
 
     if (!atomic_dec_and_test(&aio_req->pending_reqs))
         return;
 
     if (aio_req->iocb->ki_flags & IOCB_DIRECT)
         inode_dio_end(inode);
 
     ret = aio_req->error;
     if (!ret)
         ret = aio_req->total_len;
 
     dout("ceph_aio_complete %p rc %d\n", inode, ret);
 
     if (ret >= 0 && aio_req->write) {
         int dirty;
 
         loff_t endoff = aio_req->iocb->ki_pos + aio_req->total_len;
         if (endoff > i_size_read(inode)) {
             if (ceph_inode_set_size(inode, endoff))
                 ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
         }
 
         spin_lock(&ci->i_ceph_lock);
         dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
                            &aio_req->prealloc_cf);
         spin_unlock(&ci->i_ceph_lock);
         if (dirty)
             __mark_inode_dirty(inode, dirty);
 
     }
 
     ceph_put_cap_refs(ci, (aio_req->write ? CEPH_CAP_FILE_WR :
                         CEPH_CAP_FILE_RD));
 
     aio_req->iocb->ki_complete(aio_req->iocb, ret);
 
     ceph_free_cap_flush(aio_req->prealloc_cf);
     kfree(aio_req);
 }
 
 static void ceph_aio_complete_req(struct ceph_osd_request *req)
 {
     int rc = req->r_result;
     struct inode *inode = req->r_inode;
     struct ceph_aio_request *aio_req = req->r_priv;
     struct ceph_osd_data *osd_data = osd_req_op_extent_osd_data(req, 0);
     struct ceph_client_metric *metric = &ceph_sb_to_mdsc(inode->i_sb)->metric;
     unsigned int len = osd_data->bvec_pos.iter.bi_size;
 
     BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_BVECS);
     BUG_ON(!osd_data->num_bvecs);
 
     dout("ceph_aio_complete_req %p rc %d bytes %u\n", inode, rc, len);
 
     if (rc == -EOLDSNAPC) {
         struct ceph_aio_work *aio_work;
         BUG_ON(!aio_req->write);
 
         aio_work = kmalloc(sizeof(*aio_work), GFP_NOFS);
         if (aio_work) {
             INIT_WORK(&aio_work->work, ceph_aio_retry_work);
             aio_work->req = req;
             queue_work(ceph_inode_to_client(inode)->inode_wq,
                    &aio_work->work);
             return;
         }
         rc = -ENOMEM;
     } else if (!aio_req->write) {
         if (rc == -ENOENT)
             rc = 0;
         if (rc >= 0 && len > rc) {
             struct iov_iter i;
             int zlen = len - rc;
 
             /*
              * If read is satisfied by single OSD request,
              * it can pass EOF. Otherwise read is within
              * i_size.
              */
             if (aio_req->num_reqs == 1) {
                 loff_t i_size = i_size_read(inode);
                 loff_t endoff = aio_req->iocb->ki_pos + rc;
                 if (endoff < i_size)
                     zlen = min_t(size_t, zlen,
                              i_size - endoff);
                 aio_req->total_len = rc + zlen;
             }
 
             iov_iter_bvec(&i, READ, osd_data->bvec_pos.bvecs,
                       osd_data->num_bvecs, len);
             iov_iter_advance(&i, rc);
             iov_iter_zero(zlen, &i);
         }
     }
 
     /* r_start_latency == 0 means the request was not submitted */
     if (req->r_start_latency) {
         if (aio_req->write)
             ceph_update_write_metrics(metric, req->r_start_latency,
                           req->r_end_latency, len, rc);
         else
             ceph_update_read_metrics(metric, req->r_start_latency,
                          req->r_end_latency, len, rc);
     }
 
     put_bvecs(osd_data->bvec_pos.bvecs, osd_data->num_bvecs,
           aio_req->should_dirty);
     ceph_osdc_put_request(req);
 
     if (rc < 0)
         cmpxchg(&aio_req->error, 0, rc);
 
     ceph_aio_complete(inode, aio_req);
     return;
 }
 
 static void ceph_aio_retry_work(struct work_struct *work)
 {
     struct ceph_aio_work *aio_work =
         container_of(work, struct ceph_aio_work, work);
     struct ceph_osd_request *orig_req = aio_work->req;
     struct ceph_aio_request *aio_req = orig_req->r_priv;
     struct inode *inode = orig_req->r_inode;
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_snap_context *snapc;
     struct ceph_osd_request *req;
     int ret;
 
     spin_lock(&ci->i_ceph_lock);
     if (__ceph_have_pending_cap_snap(ci)) {
         struct ceph_cap_snap *capsnap =
             list_last_entry(&ci->i_cap_snaps,
                     struct ceph_cap_snap,
                     ci_item);
         snapc = ceph_get_snap_context(capsnap->context);
     } else {
         BUG_ON(!ci->i_head_snapc);
         snapc = ceph_get_snap_context(ci->i_head_snapc);
     }
     spin_unlock(&ci->i_ceph_lock);
 
     req = ceph_osdc_alloc_request(orig_req->r_osdc, snapc, 1,
             false, GFP_NOFS);
     if (!req) {
         ret = -ENOMEM;
         req = orig_req;
         goto out;
     }
 
     req->r_flags = /* CEPH_OSD_FLAG_ORDERSNAP | */ CEPH_OSD_FLAG_WRITE;
     ceph_oloc_copy(&req->r_base_oloc, &orig_req->r_base_oloc);
     ceph_oid_copy(&req->r_base_oid, &orig_req->r_base_oid);
 
     req->r_ops[0] = orig_req->r_ops[0];
 
     req->r_mtime = aio_req->mtime;
     req->r_data_offset = req->r_ops[0].extent.offset;
 
     ret = ceph_osdc_alloc_messages(req, GFP_NOFS);
     if (ret) {
         ceph_osdc_put_request(req);
         req = orig_req;
         goto out;
     }
 
     ceph_osdc_put_request(orig_req);
 
     req->r_callback = ceph_aio_complete_req;
     req->r_inode = inode;
     req->r_priv = aio_req;
 
     ceph_osdc_start_request(req->r_osdc, req);
 out:
     if (ret < 0) {
         req->r_result = ret;
         ceph_aio_complete_req(req);
     }
 
     ceph_put_snap_context(snapc);
     kfree(aio_work);
 }
 
 static ssize_t
 ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
                struct ceph_snap_context *snapc,
                struct ceph_cap_flush **pcf)
 {
     struct file *file = iocb->ki_filp;
     struct inode *inode = file_inode(file);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
     struct ceph_client_metric *metric = &fsc->mdsc->metric;
     struct ceph_vino vino;
     struct ceph_osd_request *req;
     struct bio_vec *bvecs;
     struct ceph_aio_request *aio_req = NULL;
     int num_pages = 0;
     int flags;
     int ret = 0;
     struct timespec64 mtime = current_time(inode);
     size_t count = iov_iter_count(iter);
     loff_t pos = iocb->ki_pos;
     bool write = iov_iter_rw(iter) == WRITE;
     bool should_dirty = !write && user_backed_iter(iter);
 
     if (write && ceph_snap(file_inode(file)) != CEPH_NOSNAP)
         return -EROFS;
 
     dout("sync_direct_%s on file %p %lld~%u snapc %p seq %lld\n",
          (write ? "write" : "read"), file, pos, (unsigned)count,
          snapc, snapc ? snapc->seq : 0);
 
     if (write) {
         int ret2;
 
         ceph_fscache_invalidate(inode, true);
 
         ret2 = invalidate_inode_pages2_range(inode->i_mapping,
                     pos >> PAGE_SHIFT,
                     (pos + count - 1) >> PAGE_SHIFT);
         if (ret2 < 0)
             dout("invalidate_inode_pages2_range returned %d\n", ret2);
 
         flags = /* CEPH_OSD_FLAG_ORDERSNAP | */ CEPH_OSD_FLAG_WRITE;
     } else {
         flags = CEPH_OSD_FLAG_READ;
     }
 
     while (iov_iter_count(iter) > 0) {
         u64 size = iov_iter_count(iter);
         ssize_t len;
 
         if (write)
             size = min_t(u64, size, fsc->mount_options->wsize);
         else
             size = min_t(u64, size, fsc->mount_options->rsize);
 
         vino = ceph_vino(inode);
         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
                         vino, pos, &size, 0,
                         1,
                         write ? CEPH_OSD_OP_WRITE :
                             CEPH_OSD_OP_READ,
                         flags, snapc,
                         ci->i_truncate_seq,
                         ci->i_truncate_size,
                         false);
         if (IS_ERR(req)) {
             ret = PTR_ERR(req);
             break;
         }
 
         len = iter_get_bvecs_alloc(iter, size, &bvecs, &num_pages);
         if (len < 0) {
             ceph_osdc_put_request(req);
             ret = len;
             break;
         }
         if (len != size)
             osd_req_op_extent_update(req, 0, len);
 
         /*
          * To simplify error handling, allow AIO when IO within i_size
          * or IO can be satisfied by single OSD request.
          */
         if (pos == iocb->ki_pos && !is_sync_kiocb(iocb) &&
             (len == count || pos + count <= i_size_read(inode))) {
             aio_req = kzalloc(sizeof(*aio_req), GFP_KERNEL);
             if (aio_req) {
                 aio_req->iocb = iocb;
                 aio_req->write = write;
                 aio_req->should_dirty = should_dirty;
                 INIT_LIST_HEAD(&aio_req->osd_reqs);
                 if (write) {
                     aio_req->mtime = mtime;
                     swap(aio_req->prealloc_cf, *pcf);
                 }
             }
             /* ignore error */
         }
 
         if (write) {
             /*
              * throw out any page cache pages in this range. this
              * may block.
              */
             truncate_inode_pages_range(inode->i_mapping, pos,
                            PAGE_ALIGN(pos + len) - 1);
 
             req->r_mtime = mtime;
         }
 
         osd_req_op_extent_osd_data_bvecs(req, 0, bvecs, num_pages, len);
 
         if (aio_req) {
             aio_req->total_len += len;
             aio_req->num_reqs++;
             atomic_inc(&aio_req->pending_reqs);
 
             req->r_callback = ceph_aio_complete_req;
             req->r_inode = inode;
             req->r_priv = aio_req;
             list_add_tail(&req->r_private_item, &aio_req->osd_reqs);
 
             pos += len;
             continue;
         }
 
         ceph_osdc_start_request(req->r_osdc, req);
         ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
 
         if (write)
             ceph_update_write_metrics(metric, req->r_start_latency,
                           req->r_end_latency, len, ret);
         else
             ceph_update_read_metrics(metric, req->r_start_latency,
                          req->r_end_latency, len, ret);
 
         size = i_size_read(inode);
         if (!write) {
             if (ret == -ENOENT)
                 ret = 0;
             if (ret >= 0 && ret < len && pos + ret < size) {
                 struct iov_iter i;
                 int zlen = min_t(size_t, len - ret,
                          size - pos - ret);
 
                 iov_iter_bvec(&i, READ, bvecs, num_pages, len);
                 iov_iter_advance(&i, ret);
                 iov_iter_zero(zlen, &i);
                 ret += zlen;
             }
             if (ret >= 0)
                 len = ret;
         }
 
         put_bvecs(bvecs, num_pages, should_dirty);
         ceph_osdc_put_request(req);
         if (ret < 0)
             break;
 
         pos += len;
         if (!write && pos >= size)
             break;
 
         if (write && pos > size) {
             if (ceph_inode_set_size(inode, pos))
                 ceph_check_caps(ceph_inode(inode),
                         CHECK_CAPS_AUTHONLY,
                         NULL);
         }
     }
 
     if (aio_req) {
         LIST_HEAD(osd_reqs);
 
         if (aio_req->num_reqs == 0) {
             kfree(aio_req);
             return ret;
         }
 
         ceph_get_cap_refs(ci, write ? CEPH_CAP_FILE_WR :
                           CEPH_CAP_FILE_RD);
 
         list_splice(&aio_req->osd_reqs, &osd_reqs);
         inode_dio_begin(inode);
         while (!list_empty(&osd_reqs)) {
             req = list_first_entry(&osd_reqs,
                            struct ceph_osd_request,
                            r_private_item);
             list_del_init(&req->r_private_item);
             if (ret >= 0)
                 ceph_osdc_start_request(req->r_osdc, req);
             if (ret < 0) {
                 req->r_result = ret;
                 ceph_aio_complete_req(req);
             }
         }
         return -EIOCBQUEUED;
     }
 
     if (ret != -EOLDSNAPC && pos > iocb->ki_pos) {
         ret = pos - iocb->ki_pos;
         iocb->ki_pos = pos;
     }
     return ret;
 }
 
 /*
  * Synchronous write, straight from __user pointer or user pages.
  *
  * If write spans object boundary, just do multiple writes.  (For a
  * correct atomic write, we should e.g. take write locks on all
  * objects, rollback on failure, etc.)
  */
 static ssize_t
 ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
         struct ceph_snap_context *snapc)
 {
     struct file *file = iocb->ki_filp;
     struct inode *inode = file_inode(file);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
     struct ceph_vino vino;
     struct ceph_osd_request *req;
     struct page **pages;
     u64 len;
     int num_pages;
     int written = 0;
     int flags;
     int ret;
     bool check_caps = false;
     struct timespec64 mtime = current_time(inode);
     size_t count = iov_iter_count(from);
 
     if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
         return -EROFS;
 
     dout("sync_write on file %p %lld~%u snapc %p seq %lld\n",
          file, pos, (unsigned)count, snapc, snapc->seq);
 
     ret = filemap_write_and_wait_range(inode->i_mapping,
                        pos, pos + count - 1);
     if (ret < 0)
         return ret;
 
     ceph_fscache_invalidate(inode, false);
     ret = invalidate_inode_pages2_range(inode->i_mapping,
                         pos >> PAGE_SHIFT,
                         (pos + count - 1) >> PAGE_SHIFT);
     if (ret < 0)
         dout("invalidate_inode_pages2_range returned %d\n", ret);
 
     flags = /* CEPH_OSD_FLAG_ORDERSNAP | */ CEPH_OSD_FLAG_WRITE;
 
     while ((len = iov_iter_count(from)) > 0) {
         size_t left;
         int n;
 
         vino = ceph_vino(inode);
         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
                         vino, pos, &len, 0, 1,
                         CEPH_OSD_OP_WRITE, flags, snapc,
                         ci->i_truncate_seq,
                         ci->i_truncate_size,
                         false);
         if (IS_ERR(req)) {
             ret = PTR_ERR(req);
             break;
         }
 
         /*
          * write from beginning of first page,
          * regardless of io alignment
          */
         num_pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 
         pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
         if (IS_ERR(pages)) {
             ret = PTR_ERR(pages);
             goto out;
         }
 
         left = len;
         for (n = 0; n < num_pages; n++) {
             size_t plen = min_t(size_t, left, PAGE_SIZE);
             ret = copy_page_from_iter(pages[n], 0, plen, from);
             if (ret != plen) {
                 ret = -EFAULT;
                 break;
             }
             left -= ret;
         }
 
         if (ret < 0) {
             ceph_release_page_vector(pages, num_pages);
             goto out;
         }
 
         req->r_inode = inode;
 
         osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
                         false, true);
 
         req->r_mtime = mtime;
         ceph_osdc_start_request(&fsc->client->osdc, req);
         ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
 
         ceph_update_write_metrics(&fsc->mdsc->metric, req->r_start_latency,
                       req->r_end_latency, len, ret);
 out:
         ceph_osdc_put_request(req);
         if (ret != 0) {
             ceph_set_error_write(ci);
             break;
         }
 
         ceph_clear_error_write(ci);
         pos += len;
         written += len;
         if (pos > i_size_read(inode)) {
             check_caps = ceph_inode_set_size(inode, pos);
             if (check_caps)
                 ceph_check_caps(ceph_inode(inode),
                         CHECK_CAPS_AUTHONLY,
                         NULL);
         }
 
     }
 
     if (ret != -EOLDSNAPC && written > 0) {
         ret = written;
         iocb->ki_pos = pos;
     }
     return ret;
 }
 
 /*
  * Wrap generic_file_aio_read with checks for cap bits on the inode.
  * Atomically grab references, so that those bits are not released
  * back to the MDS mid-read.
  *
  * Hmm, the sync read case isn't actually async... should it be?
  */
 static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
     struct file *filp = iocb->ki_filp;
     struct ceph_file_info *fi = filp->private_data;
     size_t len = iov_iter_count(to);
     struct inode *inode = file_inode(filp);
     struct ceph_inode_info *ci = ceph_inode(inode);
     bool direct_lock = iocb->ki_flags & IOCB_DIRECT;
     ssize_t ret;
     int want = 0, got = 0;
     int retry_op = 0, read = 0;
 
 again:
     dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
          inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
 
     if (ceph_inode_is_shutdown(inode))
         return -ESTALE;
 
     if (direct_lock)
         ceph_start_io_direct(inode);
     else
         ceph_start_io_read(inode);
 
     if (!(fi->flags & CEPH_F_SYNC) && !direct_lock)
         want |= CEPH_CAP_FILE_CACHE;
     if (fi->fmode & CEPH_FILE_MODE_LAZY)
         want |= CEPH_CAP_FILE_LAZYIO;
 
     ret = ceph_get_caps(filp, CEPH_CAP_FILE_RD, want, -1, &got);
     if (ret < 0) {
         if (direct_lock)
             ceph_end_io_direct(inode);
         else
             ceph_end_io_read(inode);
         return ret;
     }
 
     if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
         (iocb->ki_flags & IOCB_DIRECT) ||
         (fi->flags & CEPH_F_SYNC)) {
 
         dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
              inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
              ceph_cap_string(got));
 
         if (!ceph_has_inline_data(ci)) {
             if (!retry_op && (iocb->ki_flags & IOCB_DIRECT)) {
                 ret = ceph_direct_read_write(iocb, to,
                                  NULL, NULL);
                 if (ret >= 0 && ret < len)
                     retry_op = CHECK_EOF;
             } else {
                 ret = ceph_sync_read(iocb, to, &retry_op);
             }
         } else {
             retry_op = READ_INLINE;
         }
     } else {
         CEPH_DEFINE_RW_CONTEXT(rw_ctx, got);
         dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
              inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
              ceph_cap_string(got));
         ceph_add_rw_context(fi, &rw_ctx);
         ret = generic_file_read_iter(iocb, to);
         ceph_del_rw_context(fi, &rw_ctx);
     }
 
     dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
          inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
     ceph_put_cap_refs(ci, got);
 
     if (direct_lock)
         ceph_end_io_direct(inode);
     else
         ceph_end_io_read(inode);
 
     if (retry_op > HAVE_RETRIED && ret >= 0) {
         int statret;
         struct page *page = NULL;
         loff_t i_size;
         if (retry_op == READ_INLINE) {
             page = __page_cache_alloc(GFP_KERNEL);
             if (!page)
                 return -ENOMEM;
         }
 
         statret = __ceph_do_getattr(inode, page,
                         CEPH_STAT_CAP_INLINE_DATA, !!page);
         if (statret < 0) {
             if (page)
                 __free_page(page);
             if (statret == -ENODATA) {
                 BUG_ON(retry_op != READ_INLINE);
                 goto again;
             }
             return statret;
         }
 
         i_size = i_size_read(inode);
         if (retry_op == READ_INLINE) {
             BUG_ON(ret > 0 || read > 0);
             if (iocb->ki_pos < i_size &&
                 iocb->ki_pos < PAGE_SIZE) {
                 loff_t end = min_t(loff_t, i_size,
                            iocb->ki_pos + len);
                 end = min_t(loff_t, end, PAGE_SIZE);
                 if (statret < end)
                     zero_user_segment(page, statret, end);
                 ret = copy_page_to_iter(page,
                         iocb->ki_pos & ~PAGE_MASK,
                         end - iocb->ki_pos, to);
                 iocb->ki_pos += ret;
                 read += ret;
             }
             if (iocb->ki_pos < i_size && read < len) {
                 size_t zlen = min_t(size_t, len - read,
                             i_size - iocb->ki_pos);
                 ret = iov_iter_zero(zlen, to);
                 iocb->ki_pos += ret;
                 read += ret;
             }
             __free_pages(page, 0);
             return read;
         }
 
         /* hit EOF or hole? */
         if (retry_op == CHECK_EOF && iocb->ki_pos < i_size &&
             ret < len) {
             dout("sync_read hit hole, ppos %lld < size %lld"
                  ", reading more\n", iocb->ki_pos, i_size);
 
             read += ret;
             len -= ret;
             retry_op = HAVE_RETRIED;
             goto again;
         }
     }
 
     if (ret >= 0)
         ret += read;
 
     return ret;
 }
 
 /*
  * Take cap references to avoid releasing caps to MDS mid-write.
  *
  * If we are synchronous, and write with an old snap context, the OSD
  * may return EOLDSNAPC.  In that case, retry the write.. _after_
  * dropping our cap refs and allowing the pending snap to logically
  * complete _before_ this write occurs.
  *
  * If we are near ENOSPC, write synchronously.
  */
 static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
     struct file *file = iocb->ki_filp;
     struct ceph_file_info *fi = file->private_data;
     struct inode *inode = file_inode(file);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
     struct ceph_osd_client *osdc = &fsc->client->osdc;
     struct ceph_cap_flush *prealloc_cf;
     ssize_t count, written = 0;
     int err, want = 0, got;
     bool direct_lock = false;
     u32 map_flags;
     u64 pool_flags;
     loff_t pos;
     loff_t limit = max(i_size_read(inode), fsc->max_file_size);
 
     if (ceph_inode_is_shutdown(inode))
         return -ESTALE;
 
     if (ceph_snap(inode) != CEPH_NOSNAP)
         return -EROFS;
 
     prealloc_cf = ceph_alloc_cap_flush();
     if (!prealloc_cf)
         return -ENOMEM;
 
     if ((iocb->ki_flags & (IOCB_DIRECT | IOCB_APPEND)) == IOCB_DIRECT)
         direct_lock = true;
 
 retry_snap:
     if (direct_lock)
         ceph_start_io_direct(inode);
     else
         ceph_start_io_write(inode);
 
     /* We can write back this queue in page reclaim */
     current->backing_dev_info = inode_to_bdi(inode);
 
     if (iocb->ki_flags & IOCB_APPEND) {
         err = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
         if (err < 0)
             goto out;
     }
 
     err = generic_write_checks(iocb, from);
     if (err <= 0)
         goto out;
 
     pos = iocb->ki_pos;
     if (unlikely(pos >= limit)) {
         err = -EFBIG;
         goto out;
     } else {
         iov_iter_truncate(from, limit - pos);
     }
 
     count = iov_iter_count(from);
     if (ceph_quota_is_max_bytes_exceeded(inode, pos + count)) {
         err = -EDQUOT;
         goto out;
     }
 
     down_read(&osdc->lock);
     map_flags = osdc->osdmap->flags;
     pool_flags = ceph_pg_pool_flags(osdc->osdmap, ci->i_layout.pool_id);
     up_read(&osdc->lock);
     if ((map_flags & CEPH_OSDMAP_FULL) ||
         (pool_flags & CEPH_POOL_FLAG_FULL)) {
         err = -ENOSPC;
         goto out;
     }
 
     err = file_remove_privs(file);
     if (err)
         goto out;
 
     dout("aio_write %p %llx.%llx %llu~%zd getting caps. i_size %llu\n",
          inode, ceph_vinop(inode), pos, count, i_size_read(inode));
     if (!(fi->flags & CEPH_F_SYNC) && !direct_lock)
         want |= CEPH_CAP_FILE_BUFFER;
     if (fi->fmode & CEPH_FILE_MODE_LAZY)
         want |= CEPH_CAP_FILE_LAZYIO;
     got = 0;
     err = ceph_get_caps(file, CEPH_CAP_FILE_WR, want, pos + count, &got);
     if (err < 0)
         goto out;
 
     err = file_update_time(file);
     if (err)
         goto out_caps;
 
     inode_inc_iversion_raw(inode);
 
     dout("aio_write %p %llx.%llx %llu~%zd got cap refs on %s\n",
          inode, ceph_vinop(inode), pos, count, ceph_cap_string(got));
 
     if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
         (iocb->ki_flags & IOCB_DIRECT) || (fi->flags & CEPH_F_SYNC) ||
         (ci->i_ceph_flags & CEPH_I_ERROR_WRITE)) {
         struct ceph_snap_context *snapc;
         struct iov_iter data;
 
         spin_lock(&ci->i_ceph_lock);
         if (__ceph_have_pending_cap_snap(ci)) {
             struct ceph_cap_snap *capsnap =
                     list_last_entry(&ci->i_cap_snaps,
                             struct ceph_cap_snap,
                             ci_item);
             snapc = ceph_get_snap_context(capsnap->context);
         } else {
             BUG_ON(!ci->i_head_snapc);
             snapc = ceph_get_snap_context(ci->i_head_snapc);
         }
         spin_unlock(&ci->i_ceph_lock);
 
         /* we might need to revert back to that point */
         data = *from;
         if (iocb->ki_flags & IOCB_DIRECT)
             written = ceph_direct_read_write(iocb, &data, snapc,
                              &prealloc_cf);
         else
             written = ceph_sync_write(iocb, &data, pos, snapc);
         if (direct_lock)
             ceph_end_io_direct(inode);
         else
             ceph_end_io_write(inode);
         if (written > 0)
             iov_iter_advance(from, written);
         ceph_put_snap_context(snapc);
     } else {
         /*
          * No need to acquire the i_truncate_mutex. Because
          * the MDS revokes Fwb caps before sending truncate
          * message to us. We can't get Fwb cap while there
          * are pending vmtruncate. So write and vmtruncate
          * can not run at the same time
          */
         written = generic_perform_write(iocb, from);
         if (likely(written >= 0))
             iocb->ki_pos = pos + written;
         ceph_end_io_write(inode);
     }
 
     if (written >= 0) {
         int dirty;
 
         spin_lock(&ci->i_ceph_lock);
         dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
                            &prealloc_cf);
         spin_unlock(&ci->i_ceph_lock);
         if (dirty)
             __mark_inode_dirty(inode, dirty);
         if (ceph_quota_is_max_bytes_approaching(inode, iocb->ki_pos))
             ceph_check_caps(ci, CHECK_CAPS_FLUSH, NULL);
     }
 
     dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
          inode, ceph_vinop(inode), pos, (unsigned)count,
          ceph_cap_string(got));
     ceph_put_cap_refs(ci, got);
 
     if (written == -EOLDSNAPC) {
         dout("aio_write %p %llx.%llx %llu~%u" "got EOLDSNAPC, retrying\n",
              inode, ceph_vinop(inode), pos, (unsigned)count);
         goto retry_snap;
     }
 
     if (written >= 0) {
         if ((map_flags & CEPH_OSDMAP_NEARFULL) ||
             (pool_flags & CEPH_POOL_FLAG_NEARFULL))
             iocb->ki_flags |= IOCB_DSYNC;
         written = generic_write_sync(iocb, written);
     }
 
     goto out_unlocked;
 out_caps:
     ceph_put_cap_refs(ci, got);
 out:
     if (direct_lock)
         ceph_end_io_direct(inode);
     else
         ceph_end_io_write(inode);
 out_unlocked:
     ceph_free_cap_flush(prealloc_cf);
     current->backing_dev_info = NULL;
     return written ? written : err;
 }
 
 /*
  * llseek.  be sure to verify file size on SEEK_END.
  */
 static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
 {
     if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
         struct inode *inode = file_inode(file);
         int ret;
 
         ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
         if (ret < 0)
             return ret;
     }
     return generic_file_llseek(file, offset, whence);
 }
 
 static inline void ceph_zero_partial_page(
     struct inode *inode, loff_t offset, unsigned size)
 {
     struct page *page;
     pgoff_t index = offset >> PAGE_SHIFT;
 
     page = find_lock_page(inode->i_mapping, index);
     if (page) {
         wait_on_page_writeback(page);
         zero_user(page, offset & (PAGE_SIZE - 1), size);
         unlock_page(page);
         put_page(page);
     }
 }
 
 static void ceph_zero_pagecache_range(struct inode *inode, loff_t offset,
                       loff_t length)
 {
     loff_t nearly = round_up(offset, PAGE_SIZE);
     if (offset < nearly) {
         loff_t size = nearly - offset;
         if (length < size)
             size = length;
         ceph_zero_partial_page(inode, offset, size);
         offset += size;
         length -= size;
     }
     if (length >= PAGE_SIZE) {
         loff_t size = round_down(length, PAGE_SIZE);
         truncate_pagecache_range(inode, offset, offset + size - 1);
         offset += size;
         length -= size;
     }
     if (length)
         ceph_zero_partial_page(inode, offset, length);
 }
 
 static int ceph_zero_partial_object(struct inode *inode,
                     loff_t offset, loff_t *length)
 {
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
     struct ceph_osd_request *req;
     int ret = 0;
     loff_t zero = 0;
     int op;
 
     if (!length) {
         op = offset ? CEPH_OSD_OP_DELETE : CEPH_OSD_OP_TRUNCATE;
         length = &zero;
     } else {
         op = CEPH_OSD_OP_ZERO;
     }
 
     req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
                     ceph_vino(inode),
                     offset, length,
                     0, 1, op,
                     CEPH_OSD_FLAG_WRITE,
                     NULL, 0, 0, false);
     if (IS_ERR(req)) {
         ret = PTR_ERR(req);
         goto out;
     }
 
     req->r_mtime = inode->i_mtime;
     ceph_osdc_start_request(&fsc->client->osdc, req);
     ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
     if (ret == -ENOENT)
         ret = 0;
     ceph_osdc_put_request(req);
 
 out:
     return ret;
 }
 
 static int ceph_zero_objects(struct inode *inode, loff_t offset, loff_t length)
 {
     int ret = 0;
     struct ceph_inode_info *ci = ceph_inode(inode);
     s32 stripe_unit = ci->i_layout.stripe_unit;
     s32 stripe_count = ci->i_layout.stripe_count;
     s32 object_size = ci->i_layout.object_size;
     u64 object_set_size = object_size * stripe_count;
     u64 nearly, t;
 
     /* round offset up to next period boundary */
     nearly = offset + object_set_size - 1;
     t = nearly;
     nearly -= do_div(t, object_set_size);
 
     while (length && offset < nearly) {
         loff_t size = length;
         ret = ceph_zero_partial_object(inode, offset, &size);
         if (ret < 0)
             return ret;
         offset += size;
         length -= size;
     }
     while (length >= object_set_size) {
         int i;
         loff_t pos = offset;
         for (i = 0; i < stripe_count; ++i) {
             ret = ceph_zero_partial_object(inode, pos, NULL);
             if (ret < 0)
                 return ret;
             pos += stripe_unit;
         }
         offset += object_set_size;
         length -= object_set_size;
     }
     while (length) {
         loff_t size = length;
         ret = ceph_zero_partial_object(inode, offset, &size);
         if (ret < 0)
             return ret;
         offset += size;
         length -= size;
     }
     return ret;
 }
 
 static long ceph_fallocate(struct file *file, int mode,
                 loff_t offset, loff_t length)
 {
     struct ceph_file_info *fi = file->private_data;
     struct inode *inode = file_inode(file);
     struct ceph_inode_info *ci = ceph_inode(inode);
     struct ceph_cap_flush *prealloc_cf;
     int want, got = 0;
     int dirty;
     int ret = 0;
     loff_t endoff = 0;
     loff_t size;
 
     if (mode != (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
         return -EOPNOTSUPP;
 
     if (!S_ISREG(inode->i_mode))
         return -EOPNOTSUPP;
 
     prealloc_cf = ceph_alloc_cap_flush();
     if (!prealloc_cf)
         return -ENOMEM;
 
     inode_lock(inode);
 
     if (ceph_snap(inode) != CEPH_NOSNAP) {
         ret = -EROFS;
         goto unlock;
     }
 
     size = i_size_read(inode);
 
     /* Are we punching a hole beyond EOF? */
     if (offset >= size)
         goto unlock;
     if ((offset + length) > size)
         length = size - offset;
 
     if (fi->fmode & CEPH_FILE_MODE_LAZY)
         want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
     else
         want = CEPH_CAP_FILE_BUFFER;
 
     ret = ceph_get_caps(file, CEPH_CAP_FILE_WR, want, endoff, &got);
     if (ret < 0)
         goto unlock;
 
     filemap_invalidate_lock(inode->i_mapping);
     ceph_fscache_invalidate(inode, false);
     ceph_zero_pagecache_range(inode, offset, length);
     ret = ceph_zero_objects(inode, offset, length);
 
     if (!ret) {
         spin_lock(&ci->i_ceph_lock);
         dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
                            &prealloc_cf);
         spin_unlock(&ci->i_ceph_lock);
         if (dirty)
             __mark_inode_dirty(inode, dirty);
     }
     filemap_invalidate_unlock(inode->i_mapping);
 
     ceph_put_cap_refs(ci, got);
 unlock:
     inode_unlock(inode);
     ceph_free_cap_flush(prealloc_cf);
     return ret;
 }
 
 /*
  * This function tries to get FILE_WR capabilities for dst_ci and FILE_RD for
  * src_ci.  Two attempts are made to obtain both caps, and an error is return if
  * this fails; zero is returned on success.
  */
 static int get_rd_wr_caps(struct file *src_filp, int *src_got,
               struct file *dst_filp,
               loff_t dst_endoff, int *dst_got)
 {
     int ret = 0;
     bool retrying = false;
 
 retry_caps:
     ret = ceph_get_caps(dst_filp, CEPH_CAP_FILE_WR, CEPH_CAP_FILE_BUFFER,
                 dst_endoff, dst_got);
     if (ret < 0)
         return ret;
 
     /*
      * Since we're already holding the FILE_WR capability for the dst file,
      * we would risk a deadlock by using ceph_get_caps.  Thus, we'll do some
      * retry dance instead to try to get both capabilities.
      */
     ret = ceph_try_get_caps(file_inode(src_filp),
                 CEPH_CAP_FILE_RD, CEPH_CAP_FILE_SHARED,
                 false, src_got);
     if (ret <= 0) {
         /* Start by dropping dst_ci caps and getting src_ci caps */
         ceph_put_cap_refs(ceph_inode(file_inode(dst_filp)), *dst_got);
         if (retrying) {
             if (!ret)
                 /* ceph_try_get_caps masks EAGAIN */
                 ret = -EAGAIN;
             return ret;
         }
         ret = ceph_get_caps(src_filp, CEPH_CAP_FILE_RD,
                     CEPH_CAP_FILE_SHARED, -1, src_got);
         if (ret < 0)
             return ret;
         /*... drop src_ci caps too, and retry */
         ceph_put_cap_refs(ceph_inode(file_inode(src_filp)), *src_got);
         retrying = true;
         goto retry_caps;
     }
     return ret;
 }
 
 static void put_rd_wr_caps(struct ceph_inode_info *src_ci, int src_got,
                struct ceph_inode_info *dst_ci, int dst_got)
 {
     ceph_put_cap_refs(src_ci, src_got);
     ceph_put_cap_refs(dst_ci, dst_got);
 }
 
 /*
  * This function does several size-related checks, returning an error if:
  *  - source file is smaller than off+len
  *  - destination file size is not OK (inode_newsize_ok())
  *  - max bytes quotas is exceeded
  */
 static int is_file_size_ok(struct inode *src_inode, struct inode *dst_inode,
                loff_t src_off, loff_t dst_off, size_t len)
 {
     loff_t size, endoff;
 
     size = i_size_read(src_inode);
     /*
      * Don't copy beyond source file EOF.  Instead of simply setting length
      * to (size - src_off), just drop to VFS default implementation, as the
      * local i_size may be stale due to other clients writing to the source
      * inode.
      */
     if (src_off + len > size) {
         dout("Copy beyond EOF (%llu + %zu > %llu)\n",
              src_off, len, size);
         return -EOPNOTSUPP;
     }
     size = i_size_read(dst_inode);
 
     endoff = dst_off + len;
     if (inode_newsize_ok(dst_inode, endoff))
         return -EOPNOTSUPP;
 
     if (ceph_quota_is_max_bytes_exceeded(dst_inode, endoff))
         return -EDQUOT;
 
     return 0;
 }
 
 static struct ceph_osd_request *
 ceph_alloc_copyfrom_request(struct ceph_osd_client *osdc,
                 u64 src_snapid,
                 struct ceph_object_id *src_oid,
                 struct ceph_object_locator *src_oloc,
                 struct ceph_object_id *dst_oid,
                 struct ceph_object_locator *dst_oloc,
                 u32 truncate_seq, u64 truncate_size)
 {
     struct ceph_osd_request *req;
     int ret;
     u32 src_fadvise_flags =
         CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL |
         CEPH_OSD_OP_FLAG_FADVISE_NOCACHE;
     u32 dst_fadvise_flags =
         CEPH_OSD_OP_FLAG_FADVISE_SEQUENTIAL |
         CEPH_OSD_OP_FLAG_FADVISE_DONTNEED;
 
     req = ceph_osdc_alloc_request(osdc, NULL, 1, false, GFP_KERNEL);
     if (!req)
         return ERR_PTR(-ENOMEM);
 
     req->r_flags = CEPH_OSD_FLAG_WRITE;
 
     ceph_oloc_copy(&req->r_t.base_oloc, dst_oloc);
     ceph_oid_copy(&req->r_t.base_oid, dst_oid);
 
     ret = osd_req_op_copy_from_init(req, src_snapid, 0,
                     src_oid, src_oloc,
                     src_fadvise_flags,
                     dst_fadvise_flags,
                     truncate_seq,
                     truncate_size,
                     CEPH_OSD_COPY_FROM_FLAG_TRUNCATE_SEQ);
     if (ret)
         goto out;
 
     ret = ceph_osdc_alloc_messages(req, GFP_KERNEL);
     if (ret)
         goto out;
 
     return req;
 
 out:
     ceph_osdc_put_request(req);
     return ERR_PTR(ret);
 }
 
 static ssize_t ceph_do_objects_copy(struct ceph_inode_info *src_ci, u64 *src_off,
                     struct ceph_inode_info *dst_ci, u64 *dst_off,
                     struct ceph_fs_client *fsc,
                     size_t len, unsigned int flags)
 {
     struct ceph_object_locator src_oloc, dst_oloc;
     struct ceph_object_id src_oid, dst_oid;
     struct ceph_osd_client *osdc;
     struct ceph_osd_request *req;
     size_t bytes = 0;
     u64 src_objnum, src_objoff, dst_objnum, dst_objoff;
     u32 src_objlen, dst_objlen;
     u32 object_size = src_ci->i_layout.object_size;
     int ret;
 
     src_oloc.pool = src_ci->i_layout.pool_id;
     src_oloc.pool_ns = ceph_try_get_string(src_ci->i_layout.pool_ns);
     dst_oloc.pool = dst_ci->i_layout.pool_id;
     dst_oloc.pool_ns = ceph_try_get_string(dst_ci->i_layout.pool_ns);
     osdc = &fsc->client->osdc;
 
     while (len >= object_size) {
         ceph_calc_file_object_mapping(&src_ci->i_layout, *src_off,
                           object_size, &src_objnum,
                           &src_objoff, &src_objlen);
         ceph_calc_file_object_mapping(&dst_ci->i_layout, *dst_off,
                           object_size, &dst_objnum,
                           &dst_objoff, &dst_objlen);
         ceph_oid_init(&src_oid);
         ceph_oid_printf(&src_oid, "%llx.%08llx",
                 src_ci->i_vino.ino, src_objnum);
         ceph_oid_init(&dst_oid);
         ceph_oid_printf(&dst_oid, "%llx.%08llx",
                 dst_ci->i_vino.ino, dst_objnum);
         /* Do an object remote copy */
         req = ceph_alloc_copyfrom_request(osdc, src_ci->i_vino.snap,
                           &src_oid, &src_oloc,
                           &dst_oid, &dst_oloc,
                           dst_ci->i_truncate_seq,
                           dst_ci->i_truncate_size);
         if (IS_ERR(req))
             ret = PTR_ERR(req);
         else {
             ceph_osdc_start_request(osdc, req);
             ret = ceph_osdc_wait_request(osdc, req);
             ceph_update_copyfrom_metrics(&fsc->mdsc->metric,
                              req->r_start_latency,
                              req->r_end_latency,
                              object_size, ret);
             ceph_osdc_put_request(req);
         }
         if (ret) {
             if (ret == -EOPNOTSUPP) {
                 fsc->have_copy_from2 = false;
                 pr_notice("OSDs don't support copy-from2; disabling copy offload\n");
             }
             dout("ceph_osdc_copy_from returned %d\n", ret);
             if (!bytes)
                 bytes = ret;
             goto out;
         }
         len -= object_size;
         bytes += object_size;
         *src_off += object_size;
         *dst_off += object_size;
     }
 
 out:
     ceph_oloc_destroy(&src_oloc);
     ceph_oloc_destroy(&dst_oloc);
     return bytes;
 }
 
 static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
                       struct file *dst_file, loff_t dst_off,
                       size_t len, unsigned int flags)
 {
     struct inode *src_inode = file_inode(src_file);
     struct inode *dst_inode = file_inode(dst_file);
     struct ceph_inode_info *src_ci = ceph_inode(src_inode);
     struct ceph_inode_info *dst_ci = ceph_inode(dst_inode);
     struct ceph_cap_flush *prealloc_cf;
     struct ceph_fs_client *src_fsc = ceph_inode_to_client(src_inode);
     loff_t size;
     ssize_t ret = -EIO, bytes;
     u64 src_objnum, dst_objnum, src_objoff, dst_objoff;
     u32 src_objlen, dst_objlen;
     int src_got = 0, dst_got = 0, err, dirty;
 
     if (src_inode->i_sb != dst_inode->i_sb) {
         struct ceph_fs_client *dst_fsc = ceph_inode_to_client(dst_inode);
 
         if (ceph_fsid_compare(&src_fsc->client->fsid,
                       &dst_fsc->client->fsid)) {
             dout("Copying files across clusters: src: %pU dst: %pU\n",
                  &src_fsc->client->fsid, &dst_fsc->client->fsid);
             return -EXDEV;
         }
     }
     if (ceph_snap(dst_inode) != CEPH_NOSNAP)
         return -EROFS;
 
     /*
      * Some of the checks below will return -EOPNOTSUPP, which will force a
      * fallback to the default VFS copy_file_range implementation.  This is
      * desirable in several cases (for ex, the 'len' is smaller than the
      * size of the objects, or in cases where that would be more
      * efficient).
      */
 
     if (ceph_test_mount_opt(src_fsc, NOCOPYFROM))
         return -EOPNOTSUPP;
 
     if (!src_fsc->have_copy_from2)
         return -EOPNOTSUPP;
 
     /*
      * Striped file layouts require that we copy partial objects, but the
      * OSD copy-from operation only supports full-object copies.  Limit
      * this to non-striped file layouts for now.
      */
     if ((src_ci->i_layout.stripe_unit != dst_ci->i_layout.stripe_unit) ||
         (src_ci->i_layout.stripe_count != 1) ||
         (dst_ci->i_layout.stripe_count != 1) ||
         (src_ci->i_layout.object_size != dst_ci->i_layout.object_size)) {
         dout("Invalid src/dst files layout\n");
         return -EOPNOTSUPP;
     }
 
     if (len < src_ci->i_layout.object_size)
         return -EOPNOTSUPP; /* no remote copy will be done */
 
     prealloc_cf = ceph_alloc_cap_flush();
     if (!prealloc_cf)
         return -ENOMEM;
 
     /* Start by sync'ing the source and destination files */
     ret = file_write_and_wait_range(src_file, src_off, (src_off + len));
     if (ret < 0) {
         dout("failed to write src file (%zd)\n", ret);
         goto out;
     }
     ret = file_write_and_wait_range(dst_file, dst_off, (dst_off + len));
     if (ret < 0) {
         dout("failed to write dst file (%zd)\n", ret);
         goto out;
     }
 
     /*
      * We need FILE_WR caps for dst_ci and FILE_RD for src_ci as other
      * clients may have dirty data in their caches.  And OSDs know nothing
      * about caps, so they can't safely do the remote object copies.
      */
     err = get_rd_wr_caps(src_file, &src_got,
                  dst_file, (dst_off + len), &dst_got);
     if (err < 0) {
         dout("get_rd_wr_caps returned %d\n", err);
         ret = -EOPNOTSUPP;
         goto out;
     }
 
     ret = is_file_size_ok(src_inode, dst_inode, src_off, dst_off, len);
     if (ret < 0)
         goto out_caps;
 
     /* Drop dst file cached pages */
     ceph_fscache_invalidate(dst_inode, false);
     ret = invalidate_inode_pages2_range(dst_inode->i_mapping,
                         dst_off >> PAGE_SHIFT,
                         (dst_off + len) >> PAGE_SHIFT);
     if (ret < 0) {
         dout("Failed to invalidate inode pages (%zd)\n", ret);
         ret = 0; /* XXX */
     }
     ceph_calc_file_object_mapping(&src_ci->i_layout, src_off,
                       src_ci->i_layout.object_size,
                       &src_objnum, &src_objoff, &src_objlen);
     ceph_calc_file_object_mapping(&dst_ci->i_layout, dst_off,
                       dst_ci->i_layout.object_size,
                       &dst_objnum, &dst_objoff, &dst_objlen);
     /* object-level offsets need to the same */
     if (src_objoff != dst_objoff) {
         ret = -EOPNOTSUPP;
         goto out_caps;
     }
 
     /*
      * Do a manual copy if the object offset isn't object aligned.
      * 'src_objlen' contains the bytes left until the end of the object,
      * starting at the src_off
      */
     if (src_objoff) {
         dout("Initial partial copy of %u bytes\n", src_objlen);
 
         /*
          * we need to temporarily drop all caps as we'll be calling
          * {read,write}_iter, which will get caps again.
          */
         put_rd_wr_caps(src_ci, src_got, dst_ci, dst_got);
         ret = do_splice_direct(src_file, &src_off, dst_file,
                        &dst_off, src_objlen, flags);
         /* Abort on short copies or on error */
         if (ret < src_objlen) {
             dout("Failed partial copy (%zd)\n", ret);
             goto out;
         }
         len -= ret;
         err = get_rd_wr_caps(src_file, &src_got,
                      dst_file, (dst_off + len), &dst_got);
         if (err < 0)
             goto out;
         err = is_file_size_ok(src_inode, dst_inode,
                       src_off, dst_off, len);
         if (err < 0)
             goto out_caps;
     }
 
     size = i_size_read(dst_inode);
     bytes = ceph_do_objects_copy(src_ci, &src_off, dst_ci, &dst_off,
                      src_fsc, len, flags);
     if (bytes <= 0) {
         if (!ret)
             ret = bytes;
         goto out_caps;
     }
     dout("Copied %zu bytes out of %zu\n", bytes, len);
     len -= bytes;
     ret += bytes;
 
     file_update_time(dst_file);
     inode_inc_iversion_raw(dst_inode);
 
     if (dst_off > size) {
         /* Let the MDS know about dst file size change */
         if (ceph_inode_set_size(dst_inode, dst_off) ||
             ceph_quota_is_max_bytes_approaching(dst_inode, dst_off))
             ceph_check_caps(dst_ci, CHECK_CAPS_AUTHONLY | CHECK_CAPS_FLUSH,
                     NULL);
     }
     /* Mark Fw dirty */
     spin_lock(&dst_ci->i_ceph_lock);
     dirty = __ceph_mark_dirty_caps(dst_ci, CEPH_CAP_FILE_WR, &prealloc_cf);
     spin_unlock(&dst_ci->i_ceph_lock);
     if (dirty)
         __mark_inode_dirty(dst_inode, dirty);
 
 out_caps:
     put_rd_wr_caps(src_ci, src_got, dst_ci, dst_got);
 
     /*
      * Do the final manual copy if we still have some bytes left, unless
      * there were errors in remote object copies (len >= object_size).
      */
     if (len && (len < src_ci->i_layout.object_size)) {
         dout("Final partial copy of %zu bytes\n", len);
         bytes = do_splice_direct(src_file, &src_off, dst_file,
                      &dst_off, len, flags);
         if (bytes > 0)
             ret += bytes;
         else
             dout("Failed partial copy (%zd)\n", bytes);
     }
 
 out:
     ceph_free_cap_flush(prealloc_cf);
 
     return ret;
 }
 
 static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
                     struct file *dst_file, loff_t dst_off,
                     size_t len, unsigned int flags)
 {
     ssize_t ret;
 
     ret = __ceph_copy_file_range(src_file, src_off, dst_file, dst_off,
                      len, flags);
 
     if (ret == -EOPNOTSUPP || ret == -EXDEV)
         ret = generic_copy_file_range(src_file, src_off, dst_file,
                           dst_off, len, flags);
     return ret;
 }
 
 const struct file_operations ceph_file_fops = {
     .open = ceph_open,
     .release = ceph_release,
     .llseek = ceph_llseek,
     .read_iter = ceph_read_iter,
     .write_iter = ceph_write_iter,
     .mmap = ceph_mmap,
     .fsync = ceph_fsync,
     .lock = ceph_lock,
     .setlease = simple_nosetlease,
     .flock = ceph_flock,
     .splice_read = generic_file_splice_read,
     .splice_write = iter_file_splice_write,
     .unlocked_ioctl = ceph_ioctl,
     .compat_ioctl = compat_ptr_ioctl,
     .fallocate  = ceph_fallocate,
     .copy_file_range = ceph_copy_file_range,
 };