diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/cifs/cifsglob.h | 5 | ||||
-rw-r--r-- | fs/cifs/cifsproto.h | 1 | ||||
-rw-r--r-- | fs/cifs/file.c | 23 | ||||
-rw-r--r-- | fs/cifs/smb2file.c | 2 |
4 files changed, 22 insertions, 9 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 8225de3c9743..6b61d4ad30b5 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1152,6 +1152,11 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file); struct cifsInodeInfo { bool can_cache_brlcks; struct list_head llist; /* locks helb by this inode */ + /* + * NOTE: Some code paths call down_read(lock_sem) twice, so + * we must always use use cifs_down_write() instead of down_write() + * for this semaphore to avoid deadlocks. + */ struct rw_semaphore lock_sem; /* protect the fields above */ /* BB add in lists for dirty pages i.e. write caching info for oplock */ struct list_head openFileList; diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 54590fd33df1..257c06c6a6c2 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -138,6 +138,7 @@ extern int cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, const unsigned int xid); extern int cifs_push_mandatory_locks(struct cifsFileInfo *cfile); +extern void cifs_down_write(struct rw_semaphore *sem); extern struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, struct tcon_link *tlink, diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 737cff7bc08a..c6bd820f9409 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -280,6 +280,13 @@ cifs_has_mand_locks(struct cifsInodeInfo *cinode) return has_locks; } +void +cifs_down_write(struct rw_semaphore *sem) +{ + while (!down_write_trylock(sem)) + msleep(10); +} + struct cifsFileInfo * cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, struct tcon_link *tlink, __u32 oplock) @@ -305,7 +312,7 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, INIT_LIST_HEAD(&fdlocks->locks); fdlocks->cfile = cfile; cfile->llist = fdlocks; - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); list_add(&fdlocks->llist, &cinode->llist); up_write(&cinode->lock_sem); @@ -438,7 +445,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) * Delete any outstanding lock records. We'll lose them when the file * is closed anyway. */ - down_write(&cifsi->lock_sem); + cifs_down_write(&cifsi->lock_sem); list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) { list_del(&li->llist); cifs_del_lock_waiters(li); @@ -947,7 +954,7 @@ static void cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock) { struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); list_add_tail(&lock->llist, &cfile->llist->locks); up_write(&cinode->lock_sem); } @@ -969,7 +976,7 @@ cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock, try_again: exist = false; - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length, lock->type, &conf_lock, CIFS_LOCK_OP); @@ -991,7 +998,7 @@ try_again: (lock->blist.next == &lock->blist)); if (!rc) goto try_again; - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); list_del_init(&lock->blist); } @@ -1044,7 +1051,7 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock) return rc; try_again: - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); if (!cinode->can_cache_brlcks) { up_write(&cinode->lock_sem); return rc; @@ -1242,7 +1249,7 @@ cifs_push_locks(struct cifsFileInfo *cfile) int rc = 0; /* we are going to update can_cache_brlcks here - need a write access */ - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); if (!cinode->can_cache_brlcks) { up_write(&cinode->lock_sem); return rc; @@ -1430,7 +1437,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, if (!buf) return -ENOMEM; - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); for (i = 0; i < 2; i++) { cur = buf; num = 0; diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c index dee5250701de..41f1a5dd33a5 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -138,7 +138,7 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, cur = buf; - down_write(&cinode->lock_sem); + cifs_down_write(&cinode->lock_sem); list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { if (flock->fl_start > li->offset || (flock->fl_start + length) < |