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/ioctl.c b/fs/reiserfs/ioctl.c
index 15cb5fe..946ccbf 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -167,7 +167,6 @@
int reiserfs_unpack(struct inode *inode, struct file *filp)
{
int retval = 0;
- int depth;
int index;
struct page *page;
struct address_space *mapping;
@@ -183,11 +182,11 @@
return 0;
}
- depth = reiserfs_write_lock_once(inode->i_sb);
-
/* we need to make sure nobody is changing the file size beneath us */
reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
+ reiserfs_write_lock(inode->i_sb);
+
write_from = inode->i_size & (blocksize - 1);
/* if we are on a block boundary, we are already unpacked. */
if (write_from == 0) {
@@ -221,6 +220,6 @@
out:
mutex_unlock(&inode->i_mutex);
- reiserfs_write_unlock_once(inode->i_sb, depth);
+ reiserfs_write_unlock(inode->i_sb);
return retval;
}