diff options
Diffstat (limited to 'fs/cifs/misc.c')
| -rw-r--r-- | fs/cifs/misc.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 524dbdfb7184..7207a63819cb 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -672,6 +672,11 @@ cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink, spin_unlock(&tlink_tcon(open->tlink)->open_file_lock); } +/* + * Critical section which runs after acquiring deferred_lock. + * As there is no reference count on cifs_deferred_close, pdclose + * should not be used outside deferred_lock. + */ bool cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose) { @@ -688,6 +693,9 @@ cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close ** return false; } +/* + * Critical section which runs after acquiring deferred_lock. + */ void cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose) { @@ -707,6 +715,9 @@ cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close * list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes); } +/* + * Critical section which runs after acquiring deferred_lock. + */ void cifs_del_deferred_close(struct cifsFileInfo *cfile) { @@ -738,15 +749,19 @@ void cifs_close_all_deferred_files(struct cifs_tcon *tcon) { struct cifsFileInfo *cfile; - struct cifsInodeInfo *cinode; struct list_head *tmp; spin_lock(&tcon->open_file_lock); list_for_each(tmp, &tcon->openFileList) { cfile = list_entry(tmp, struct cifsFileInfo, tlist); - cinode = CIFS_I(d_inode(cfile->dentry)); - if (delayed_work_pending(&cfile->deferred)) - mod_delayed_work(deferredclose_wq, &cfile->deferred, 0); + 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); + } } spin_unlock(&tcon->open_file_lock); } |