reiserfs: locking, handle nested locks properly
The reiserfs write lock replaced the BKL and uses similar semantics.
Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.
The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.
This patch implements that and adds a number of places where the lock
should be dropped.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c
index 03e4ca5..1fd2051 100644
--- a/fs/reiserfs/dir.c
+++ b/fs/reiserfs/dir.c
@@ -71,6 +71,7 @@
char small_buf[32]; /* avoid kmalloc if we can */
struct reiserfs_dir_entry de;
int ret = 0;
+ int depth;
reiserfs_write_lock(inode->i_sb);
@@ -181,17 +182,17 @@
* Since filldir might sleep, we can release
* the write lock here for other waiters
*/
- reiserfs_write_unlock(inode->i_sb);
+ depth = reiserfs_write_unlock_nested(inode->i_sb);
if (!dir_emit
(ctx, local_buf, d_reclen, d_ino,
DT_UNKNOWN)) {
- reiserfs_write_lock(inode->i_sb);
+ reiserfs_write_lock_nested(inode->i_sb, depth);
if (local_buf != small_buf) {
kfree(local_buf);
}
goto end;
}
- reiserfs_write_lock(inode->i_sb);
+ reiserfs_write_lock_nested(inode->i_sb, depth);
if (local_buf != small_buf) {
kfree(local_buf);
}