xfs: only lock the rt bitmap inode once per allocation
Currently both xfs_rtpick_extent and xfs_rtallocate_extent call
xfs_trans_iget to grab and lock the rt bitmap inode, which results in a
deadlock since the removal of the lock recursion counters in commit
"xfs: simplify inode to transaction joining"
Fix this by acquiring and locking the inode in xfs_bmap_rtalloc before
calling into xfs_rtpick_extent and xfs_rtallocate_extent.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index dc3afd77..2f89af2 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2333,6 +2333,7 @@
xfs_extlen_t prod = 0; /* product factor for allocators */
xfs_extlen_t ralen = 0; /* realtime allocation length */
xfs_extlen_t align; /* minimum allocation alignment */
+ xfs_inode_t *ip; /* bitmap incore inode */
xfs_rtblock_t rtb;
mp = ap->ip->i_mount;
@@ -2365,6 +2366,16 @@
*/
if (ralen * mp->m_sb.sb_rextsize >= MAXEXTLEN)
ralen = MAXEXTLEN / mp->m_sb.sb_rextsize;
+
+ /*
+ * Lock out other modifications to the RT bitmap inode.
+ */
+ error = xfs_trans_iget(mp, ap->tp, mp->m_sb.sb_rbmino, 0,
+ XFS_ILOCK_EXCL, &ip);
+ if (error)
+ return error;
+ ASSERT(ip == mp->m_rbmip);
+
/*
* If it's an allocation to an empty file at offset 0,
* pick an extent that will space things out in the rt area.