xfs: stop using xfs_trans_iget in the RT allocator

During mount we establish references to the RT inodes, which we keep for
the lifetime of the filesystem.  Instead of using xfs_trans_iget to grab
additional references when adding RT inodes to transactions use the
combination of xfs_ilock and xfs_trans_ijoin_ref, which archives the same
end result with less overhead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index d8d090665283..e7b441db0530 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2333,7 +2333,6 @@ xfs_bmap_rtalloc(
         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;
@@ -2370,11 +2369,8 @@ xfs_bmap_rtalloc(
         /*
          * 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 | XFS_ILOCK_RTBITMAP, &ip);
-        if (error)
-                return error;
-        ASSERT(ip == mp->m_rbmip);
+        xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
+        xfs_trans_ijoin_ref(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
 
         /*
          * If it's an allocation to an empty file at offset 0,