introduce I_SYNC

I_LOCK was used for several unrelated purposes, which caused deadlock
situations in certain filesystems as a side effect.  One of the purposes
now uses the new I_SYNC bit.

Also document the various bits and change their order from historical to
logical.

[bunk@stusta.de: make fs/inode.c:wake_up_inode() static]
Signed-off-by: Joern Engel <joern@wohnheim.fh-wedel.de>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index 7aa1f7004eaf..e7c60ae6b5b2 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -1289,7 +1289,14 @@ int txCommit(tid_t tid,		/* transaction identifier */
                  * commit the transaction synchronously, so the last iput
                  * will be done by the calling thread (or later)
                  */
-                if (tblk->u.ip->i_state & I_LOCK)
+                /*
+                 * I believe this code is no longer needed.  Splitting I_LOCK
+                 * into two bits, I_LOCK and I_SYNC should prevent this
+                 * deadlock as well.  But since I don't have a JFS testload
+                 * to verify this, only a trivial s/I_LOCK/I_SYNC/ was done.
+                 * Joern
+                 */
+                if (tblk->u.ip->i_state & I_SYNC)
                         tblk->xflag &= ~COMMIT_LAZY;
         }