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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-or-later
 /* AFS filesystem file handling
  *
  * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  */
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 #include <linux/writeback.h>
 #include <linux/gfp.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/netfs.h>
 #include "internal.h"
 
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
 static int afs_symlink_read_folio(struct file *file, struct folio *folio);
 static void afs_invalidate_folio(struct folio *folio, size_t offset,
                    size_t length);
 static bool afs_release_folio(struct folio *folio, gfp_t gfp_flags);
 
 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
 static void afs_vm_open(struct vm_area_struct *area);
 static void afs_vm_close(struct vm_area_struct *area);
 static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff);
 
 const struct file_operations afs_file_operations = {
     .open       = afs_open,
     .release    = afs_release,
     .llseek     = generic_file_llseek,
     .read_iter  = afs_file_read_iter,
     .write_iter = afs_file_write,
     .mmap       = afs_file_mmap,
     .splice_read    = generic_file_splice_read,
     .splice_write   = iter_file_splice_write,
     .fsync      = afs_fsync,
     .lock       = afs_lock,
     .flock      = afs_flock,
 };
 
 const struct inode_operations afs_file_inode_operations = {
     .getattr    = afs_getattr,
     .setattr    = afs_setattr,
     .permission = afs_permission,
 };
 
 const struct address_space_operations afs_file_aops = {
     .read_folio = netfs_read_folio,
     .readahead  = netfs_readahead,
     .dirty_folio    = afs_dirty_folio,
     .launder_folio  = afs_launder_folio,
     .release_folio  = afs_release_folio,
     .invalidate_folio = afs_invalidate_folio,
     .write_begin    = afs_write_begin,
     .write_end  = afs_write_end,
     .writepage  = afs_writepage,
     .writepages = afs_writepages,
 };
 
 const struct address_space_operations afs_symlink_aops = {
     .read_folio = afs_symlink_read_folio,
     .release_folio  = afs_release_folio,
     .invalidate_folio = afs_invalidate_folio,
 };
 
 static const struct vm_operations_struct afs_vm_ops = {
     .open       = afs_vm_open,
     .close      = afs_vm_close,
     .fault      = filemap_fault,
     .map_pages  = afs_vm_map_pages,
     .page_mkwrite   = afs_page_mkwrite,
 };
 
 /*
  * Discard a pin on a writeback key.
  */
 void afs_put_wb_key(struct afs_wb_key *wbk)
 {
     if (wbk && refcount_dec_and_test(&wbk->usage)) {
         key_put(wbk->key);
         kfree(wbk);
     }
 }
 
 /*
  * Cache key for writeback.
  */
 int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af)
 {
     struct afs_wb_key *wbk, *p;
 
     wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL);
     if (!wbk)
         return -ENOMEM;
     refcount_set(&wbk->usage, 2);
     wbk->key = af->key;
 
     spin_lock(&vnode->wb_lock);
     list_for_each_entry(p, &vnode->wb_keys, vnode_link) {
         if (p->key == wbk->key)
             goto found;
     }
 
     key_get(wbk->key);
     list_add_tail(&wbk->vnode_link, &vnode->wb_keys);
     spin_unlock(&vnode->wb_lock);
     af->wb = wbk;
     return 0;
 
 found:
     refcount_inc(&p->usage);
     spin_unlock(&vnode->wb_lock);
     af->wb = p;
     kfree(wbk);
     return 0;
 }
 
 /*
  * open an AFS file or directory and attach a key to it
  */
 int afs_open(struct inode *inode, struct file *file)
 {
     struct afs_vnode *vnode = AFS_FS_I(inode);
     struct afs_file *af;
     struct key *key;
     int ret;
 
     _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
 
     key = afs_request_key(vnode->volume->cell);
     if (IS_ERR(key)) {
         ret = PTR_ERR(key);
         goto error;
     }
 
     af = kzalloc(sizeof(*af), GFP_KERNEL);
     if (!af) {
         ret = -ENOMEM;
         goto error_key;
     }
     af->key = key;
 
     ret = afs_validate(vnode, key);
     if (ret < 0)
         goto error_af;
 
     if (file->f_mode & FMODE_WRITE) {
         ret = afs_cache_wb_key(vnode, af);
         if (ret < 0)
             goto error_af;
     }
 
     if (file->f_flags & O_TRUNC)
         set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags);
 
     fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE);
 
     file->private_data = af;
     _leave(" = 0");
     return 0;
 
 error_af:
     kfree(af);
 error_key:
     key_put(key);
 error:
     _leave(" = %d", ret);
     return ret;
 }
 
 /*
  * release an AFS file or directory and discard its key
  */
 int afs_release(struct inode *inode, struct file *file)
 {
     struct afs_vnode_cache_aux aux;
     struct afs_vnode *vnode = AFS_FS_I(inode);
     struct afs_file *af = file->private_data;
     loff_t i_size;
     int ret = 0;
 
     _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode);
 
     if ((file->f_mode & FMODE_WRITE))
         ret = vfs_fsync(file, 0);
 
     file->private_data = NULL;
     if (af->wb)
         afs_put_wb_key(af->wb);
 
     if ((file->f_mode & FMODE_WRITE)) {
         i_size = i_size_read(&vnode->netfs.inode);
         afs_set_cache_aux(vnode, &aux);
         fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size);
     } else {
         fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL);
     }
 
     key_put(af->key);
     kfree(af);
     afs_prune_wb_keys(vnode);
     _leave(" = %d", ret);
     return ret;
 }
 
 /*
  * Allocate a new read record.
  */
 struct afs_read *afs_alloc_read(gfp_t gfp)
 {
     struct afs_read *req;
 
     req = kzalloc(sizeof(struct afs_read), gfp);
     if (req)
         refcount_set(&req->usage, 1);
 
     return req;
 }
 
 /*
  * Dispose of a ref to a read record.
  */
 void afs_put_read(struct afs_read *req)
 {
     if (refcount_dec_and_test(&req->usage)) {
         if (req->cleanup)
             req->cleanup(req);
         key_put(req->key);
         kfree(req);
     }
 }
 
 static void afs_fetch_data_notify(struct afs_operation *op)
 {
     struct afs_read *req = op->fetch.req;
     struct netfs_io_subrequest *subreq = req->subreq;
     int error = op->error;
 
     if (error == -ECONNABORTED)
         error = afs_abort_to_error(op->ac.abort_code);
     req->error = error;
 
     if (subreq) {
         __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
         netfs_subreq_terminated(subreq, error ?: req->actual_len, false);
         req->subreq = NULL;
     } else if (req->done) {
         req->done(req);
     }
 }
 
 static void afs_fetch_data_success(struct afs_operation *op)
 {
     struct afs_vnode *vnode = op->file[0].vnode;
 
     _enter("op=%08x", op->debug_id);
     afs_vnode_commit_status(op, &op->file[0]);
     afs_stat_v(vnode, n_fetches);
     atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes);
     afs_fetch_data_notify(op);
 }
 
 static void afs_fetch_data_put(struct afs_operation *op)
 {
     op->fetch.req->error = op->error;
     afs_put_read(op->fetch.req);
 }
 
 static const struct afs_operation_ops afs_fetch_data_operation = {
     .issue_afs_rpc  = afs_fs_fetch_data,
     .issue_yfs_rpc  = yfs_fs_fetch_data,
     .success    = afs_fetch_data_success,
     .aborted    = afs_check_for_remote_deletion,
     .failed     = afs_fetch_data_notify,
     .put        = afs_fetch_data_put,
 };
 
 /*
  * Fetch file data from the volume.
  */
 int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req)
 {
     struct afs_operation *op;
 
     _enter("%s{%llx:%llu.%u},%x,,,",
            vnode->volume->name,
            vnode->fid.vid,
            vnode->fid.vnode,
            vnode->fid.unique,
            key_serial(req->key));
 
     op = afs_alloc_operation(req->key, vnode->volume);
     if (IS_ERR(op)) {
         if (req->subreq)
             netfs_subreq_terminated(req->subreq, PTR_ERR(op), false);
         return PTR_ERR(op);
     }
 
     afs_op_set_vnode(op, 0, vnode);
 
     op->fetch.req   = afs_get_read(req);
     op->ops     = &afs_fetch_data_operation;
     return afs_do_sync_operation(op);
 }
 
 static void afs_issue_read(struct netfs_io_subrequest *subreq)
 {
     struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode);
     struct afs_read *fsreq;
 
     fsreq = afs_alloc_read(GFP_NOFS);
     if (!fsreq)
         return netfs_subreq_terminated(subreq, -ENOMEM, false);
 
     fsreq->subreq   = subreq;
     fsreq->pos  = subreq->start + subreq->transferred;
     fsreq->len  = subreq->len   - subreq->transferred;
     fsreq->key  = key_get(subreq->rreq->netfs_priv);
     fsreq->vnode    = vnode;
     fsreq->iter = &fsreq->def_iter;
 
     iov_iter_xarray(&fsreq->def_iter, READ,
             &fsreq->vnode->netfs.inode.i_mapping->i_pages,
             fsreq->pos, fsreq->len);
 
     afs_fetch_data(fsreq->vnode, fsreq);
     afs_put_read(fsreq);
 }
 
 static int afs_symlink_read_folio(struct file *file, struct folio *folio)
 {
     struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host);
     struct afs_read *fsreq;
     int ret;
 
     fsreq = afs_alloc_read(GFP_NOFS);
     if (!fsreq)
         return -ENOMEM;
 
     fsreq->pos  = folio_pos(folio);
     fsreq->len  = folio_size(folio);
     fsreq->vnode    = vnode;
     fsreq->iter = &fsreq->def_iter;
     iov_iter_xarray(&fsreq->def_iter, READ, &folio->mapping->i_pages,
             fsreq->pos, fsreq->len);
 
     ret = afs_fetch_data(fsreq->vnode, fsreq);
     if (ret == 0)
         folio_mark_uptodate(folio);
     folio_unlock(folio);
     return ret;
 }
 
 static int afs_init_request(struct netfs_io_request *rreq, struct file *file)
 {
     rreq->netfs_priv = key_get(afs_file_key(file));
     return 0;
 }
 
 static int afs_begin_cache_operation(struct netfs_io_request *rreq)
 {
 #ifdef CONFIG_AFS_FSCACHE
     struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
 
     return fscache_begin_read_operation(&rreq->cache_resources,
                         afs_vnode_cache(vnode));
 #else
     return -ENOBUFS;
 #endif
 }
 
 static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
                  struct folio **foliop, void **_fsdata)
 {
     struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
 
     return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
 }
 
 static void afs_free_request(struct netfs_io_request *rreq)
 {
     key_put(rreq->netfs_priv);
 }
 
 const struct netfs_request_ops afs_req_ops = {
     .init_request       = afs_init_request,
     .free_request       = afs_free_request,
     .begin_cache_operation  = afs_begin_cache_operation,
     .check_write_begin  = afs_check_write_begin,
     .issue_read     = afs_issue_read,
 };
 
 int afs_write_inode(struct inode *inode, struct writeback_control *wbc)
 {
     fscache_unpin_writeback(wbc, afs_vnode_cache(AFS_FS_I(inode)));
     return 0;
 }
 
 /*
  * Adjust the dirty region of the page on truncation or full invalidation,
  * getting rid of the markers altogether if the region is entirely invalidated.
  */
 static void afs_invalidate_dirty(struct folio *folio, size_t offset,
                  size_t length)
 {
     struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
     unsigned long priv;
     unsigned int f, t, end = offset + length;
 
     priv = (unsigned long)folio_get_private(folio);
 
     /* we clean up only if the entire page is being invalidated */
     if (offset == 0 && length == folio_size(folio))
         goto full_invalidate;
 
      /* If the page was dirtied by page_mkwrite(), the PTE stays writable
       * and we don't get another notification to tell us to expand it
       * again.
       */
     if (afs_is_folio_dirty_mmapped(priv))
         return;
 
     /* We may need to shorten the dirty region */
     f = afs_folio_dirty_from(folio, priv);
     t = afs_folio_dirty_to(folio, priv);
 
     if (t <= offset || f >= end)
         return; /* Doesn't overlap */
 
     if (f < offset && t > end)
         return; /* Splits the dirty region - just absorb it */
 
     if (f >= offset && t <= end)
         goto undirty;
 
     if (f < offset)
         t = offset;
     else
         f = end;
     if (f == t)
         goto undirty;
 
     priv = afs_folio_dirty(folio, f, t);
     folio_change_private(folio, (void *)priv);
     trace_afs_folio_dirty(vnode, tracepoint_string("trunc"), folio);
     return;
 
 undirty:
     trace_afs_folio_dirty(vnode, tracepoint_string("undirty"), folio);
     folio_clear_dirty_for_io(folio);
 full_invalidate:
     trace_afs_folio_dirty(vnode, tracepoint_string("inval"), folio);
     folio_detach_private(folio);
 }
 
 /*
  * invalidate part or all of a page
  * - release a page and clean up its private data if offset is 0 (indicating
  *   the entire page)
  */
 static void afs_invalidate_folio(struct folio *folio, size_t offset,
                    size_t length)
 {
     _enter("{%lu},%zu,%zu", folio->index, offset, length);
 
     BUG_ON(!folio_test_locked(folio));
 
     if (folio_get_private(folio))
         afs_invalidate_dirty(folio, offset, length);
 
     folio_wait_fscache(folio);
     _leave("");
 }
 
 /*
  * release a page and clean up its private state if it's not busy
  * - return true if the page can now be released, false if not
  */
 static bool afs_release_folio(struct folio *folio, gfp_t gfp)
 {
     struct afs_vnode *vnode = AFS_FS_I(folio_inode(folio));
 
     _enter("{{%llx:%llu}[%lu],%lx},%x",
            vnode->fid.vid, vnode->fid.vnode, folio_index(folio), folio->flags,
            gfp);
 
     /* deny if folio is being written to the cache and the caller hasn't
      * elected to wait */
 #ifdef CONFIG_AFS_FSCACHE
     if (folio_test_fscache(folio)) {
         if (current_is_kswapd() || !(gfp & __GFP_FS))
             return false;
         folio_wait_fscache(folio);
     }
     fscache_note_page_release(afs_vnode_cache(vnode));
 #endif
 
     if (folio_test_private(folio)) {
         trace_afs_folio_dirty(vnode, tracepoint_string("rel"), folio);
         folio_detach_private(folio);
     }
 
     /* Indicate that the folio can be released */
     _leave(" = T");
     return true;
 }
 
 static void afs_add_open_mmap(struct afs_vnode *vnode)
 {
     if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) {
         down_write(&vnode->volume->cell->fs_open_mmaps_lock);
 
         if (list_empty(&vnode->cb_mmap_link))
             list_add_tail(&vnode->cb_mmap_link,
                       &vnode->volume->cell->fs_open_mmaps);
 
         up_write(&vnode->volume->cell->fs_open_mmaps_lock);
     }
 }
 
 static void afs_drop_open_mmap(struct afs_vnode *vnode)
 {
     if (!atomic_dec_and_test(&vnode->cb_nr_mmap))
         return;
 
     down_write(&vnode->volume->cell->fs_open_mmaps_lock);
 
     if (atomic_read(&vnode->cb_nr_mmap) == 0)
         list_del_init(&vnode->cb_mmap_link);
 
     up_write(&vnode->volume->cell->fs_open_mmaps_lock);
     flush_work(&vnode->cb_work);
 }
 
 /*
  * Handle setting up a memory mapping on an AFS file.
  */
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
     struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
     int ret;
 
     afs_add_open_mmap(vnode);
 
     ret = generic_file_mmap(file, vma);
     if (ret == 0)
         vma->vm_ops = &afs_vm_ops;
     else
         afs_drop_open_mmap(vnode);
     return ret;
 }
 
 static void afs_vm_open(struct vm_area_struct *vma)
 {
     afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
 }
 
 static void afs_vm_close(struct vm_area_struct *vma)
 {
     afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file)));
 }
 
 static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
 {
     struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file));
     struct afs_file *af = vmf->vma->vm_file->private_data;
 
     switch (afs_validate(vnode, af->key)) {
     case 0:
         return filemap_map_pages(vmf, start_pgoff, end_pgoff);
     case -ENOMEM:
         return VM_FAULT_OOM;
     case -EINTR:
     case -ERESTARTSYS:
         return VM_FAULT_RETRY;
     case -ESTALE:
     default:
         return VM_FAULT_SIGBUS;
     }
 }
 
 static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
     struct afs_vnode *vnode = AFS_FS_I(file_inode(iocb->ki_filp));
     struct afs_file *af = iocb->ki_filp->private_data;
     int ret;
 
     ret = afs_validate(vnode, af->key);
     if (ret < 0)
         return ret;
 
     return generic_file_read_iter(iocb, iter);
 }

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