xfs: remove i_iolock and use i_rwsem in the VFS inode instead
This patch drops the XFS-own i_iolock and uses the VFS i_rwsem which
recently replaced i_mutex instead. This means we only have to take
one lock instead of two in many fast path operations, and we can
also shrink the xfs_inode structure. Thanks to the xfs_ilock family
there is very little churn, the only thing of note is that we need
to switch to use the lock_two_directory helper for taking the i_rwsem
on two inodes in a few places to make sure our lock order matches
the one used in the VFS.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 9c3e5c6..ff4d631 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -70,8 +70,6 @@ xfs_inode_alloc(
ASSERT(!xfs_isiflocked(ip));
ASSERT(ip->i_ino == 0);
- mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
-
/* initialise the xfs inode */
ip->i_ino = ino;
ip->i_mount = mp;
@@ -394,8 +392,8 @@ xfs_iget_cache_hit(
xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
inode->i_state = I_NEW;
- ASSERT(!rwsem_is_locked(&ip->i_iolock.mr_lock));
- mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
+ ASSERT(!rwsem_is_locked(&inode->i_rwsem));
+ init_rwsem(&inode->i_rwsem);
spin_unlock(&ip->i_flags_lock);
spin_unlock(&pag->pag_ici_lock);