diff options
| author | Rohith Surabattula <rohiths@microsoft.com> | 2021-08-09 12:32:46 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2021-08-12 19:29:58 +0300 |
| commit | 9e992755be8f2d458a0bcbefd19e493483c1dba2 (patch) | |
| tree | f2d011d7355544948986ce55a2797ec494526906 /fs/cifs/misc.c | |
| parent | 41535701da3324b80029cabb501e86c4fafe339d (diff) | |
| download | linux-9e992755be8f2d458a0bcbefd19e493483c1dba2.tar.xz | |
cifs: Call close synchronously during unlink/rename/lease break.
During unlink/rename/lease break, deferred work for close is
scheduled immediately but in an asynchronous manner which might
lead to race with actual(unlink/rename) commands.
This change will schedule close synchronously which will avoid
the race conditions with other commands.
Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Cc: stable@vger.kernel.org # 5.13
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/misc.c')
| -rw-r--r-- | fs/cifs/misc.c | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index cdb1ec1461de..9469f1cf0b46 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -723,20 +723,32 @@ void cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode) { struct cifsFileInfo *cfile = NULL; + struct file_list *tmp_list, *tmp_next_list; + struct list_head file_head; if (cifs_inode == NULL) return; + INIT_LIST_HEAD(&file_head); + spin_lock(&cifs_inode->open_file_lock); list_for_each_entry(cfile, &cifs_inode->openFileList, flist) { if (delayed_work_pending(&cfile->deferred)) { - /* - * If there is no pending work, mod_delayed_work queues new work. - * So, Increase the ref count to avoid use-after-free. - */ - if (!mod_delayed_work(deferredclose_wq, &cfile->deferred, 0)) - cifsFileInfo_get(cfile); + if (cancel_delayed_work(&cfile->deferred)) { + tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); + if (tmp_list == NULL) + continue; + tmp_list->cfile = cfile; + list_add_tail(&tmp_list->list, &file_head); + } } } + spin_unlock(&cifs_inode->open_file_lock); + + list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { + _cifsFileInfo_put(tmp_list->cfile, true, false); + list_del(&tmp_list->list); + kfree(tmp_list); + } } void @@ -744,20 +756,30 @@ cifs_close_all_deferred_files(struct cifs_tcon *tcon) { struct cifsFileInfo *cfile; struct list_head *tmp; + struct file_list *tmp_list, *tmp_next_list; + struct list_head file_head; + INIT_LIST_HEAD(&file_head); spin_lock(&tcon->open_file_lock); list_for_each(tmp, &tcon->openFileList) { cfile = list_entry(tmp, struct cifsFileInfo, tlist); if (delayed_work_pending(&cfile->deferred)) { - /* - * If there is no pending work, mod_delayed_work queues new work. - * So, Increase the ref count to avoid use-after-free. - */ - if (!mod_delayed_work(deferredclose_wq, &cfile->deferred, 0)) - cifsFileInfo_get(cfile); + if (cancel_delayed_work(&cfile->deferred)) { + tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC); + if (tmp_list == NULL) + continue; + tmp_list->cfile = cfile; + list_add_tail(&tmp_list->list, &file_head); + } } } spin_unlock(&tcon->open_file_lock); + + list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) { + _cifsFileInfo_put(tmp_list->cfile, true, false); + list_del(&tmp_list->list); + kfree(tmp_list); + } } /* parses DFS refferal V3 structure |