Surround VFS posix_lock_file_wait calls with CIFS lock_mutex
where it needs.
Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
---
fs/cifs/file.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 52 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 17dae68..eeb1ba5 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -669,6 +669,21 @@ cifs_del_lock_waiters(struct cifsLockInfo *lock)
}
}
+/*
+ * Copied from fs/locks.c with small changes.
+ * Remove waiter from blocker's block list.
+ * When blocker ends up pointing to itself then the list is empty.
+ */
+static void
+cifs_locks_delete_block(struct file_lock *waiter)
+{
+ lock_flocks();
+ list_del_init(&waiter->fl_block);
+ list_del_init(&waiter->fl_link);
+ waiter->fl_next = NULL;
+ unlock_flocks();
+}
+
static bool
__cifs_find_fid_lock_conflict(struct cifsFileInfo *cfile, __u64 offset,
__u64 length, __u8 type, __u16 netfid,
@@ -847,6 +862,39 @@ cifs_posix_lock_test(struct file *file, struct file_lock *flock)
return rc;
}
+/* Called with locked lock_mutex, return with unlocked. */
+static int
+cifs_posix_lock_file_wait_locked(struct file *file, struct file_lock *flock)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
+ int rc;
+
+ while (true) {
+ rc = posix_lock_file(file, flock, NULL);
+ mutex_unlock(&cinode->lock_mutex);
+ if (rc != FILE_LOCK_DEFERRED)
+ break;
+ rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
+ if (!rc) {
+ mutex_lock(&cinode->lock_mutex);
+ continue;
+ }
+ cifs_locks_delete_block(flock);
+ break;
+ }
+ return rc;
+}
+
+static int
+cifs_posix_lock_file_wait(struct file *file, struct file_lock *flock)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
+
+ mutex_unlock(&cinode->lock_mutex);
+ /* lock_mutex will be released by the function below */
+ return cifs_posix_lock_file_wait_locked(file, flock);
+}
+
/*
* Set the byte-range lock (posix style). Returns:
* 1) 0, if we set the lock and don't need to request to the server;
@@ -867,9 +915,9 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
mutex_unlock(&cinode->lock_mutex);
return rc;
}
- rc = posix_lock_file_wait(file, flock);
- mutex_unlock(&cinode->lock_mutex);
- return rc;
+
+ /* lock_mutex will be released by the function below */
+ return cifs_posix_lock_file_wait_locked(file, flock);
}
static int
@@ -1359,7 +1407,7 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u8 type,
out:
if (flock->fl_flags & FL_POSIX)
- posix_lock_file_wait(file, flock);
+ cifs_posix_lock_file_wait(file, flock);
return rc;
}
--
1.7.1
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