xfs: cleanup fdblock/frextent accounting in xfs_bmap_del_extent_delay

The code to account fdblocks and frextents in xfs_bmap_del_extent_delay
is a bit weird in that it accounts frextents before the iext tree
manipulations and fdblocks after it.  Given that the iext tree
manipulations cannot fail currently that's not really a problem, but
still odd.  Move the frextent manipulation to the end, and use a
fdblocks variable to account of the unconditional indirect blocks and
the data blocks only freed for !RT.  This prepares for following
updates in the area and already makes the code more readable.

Also remove the !isrt assert given that this code clearly handles
rt extents correctly, and we'll soon reinstate delalloc support for
RT inodes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index f14224ff4d561d2e24a22e7df88ef0e3aeb615e9..d7a5ce2e4305af8f7d980644667eb0b728f4f162 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4919,6 +4919,7 @@ xfs_bmap_del_extent_delay(
        xfs_fileoff_t           del_endoff, got_endoff;
        xfs_filblks_t           got_indlen, new_indlen, stolen;
        uint32_t                state = xfs_bmap_fork_to_state(whichfork);
+       uint64_t                fdblocks;
        int                     error = 0;
        bool                    isrt;
 
@@ -4934,15 +4935,11 @@ xfs_bmap_del_extent_delay(
        ASSERT(got->br_startoff <= del->br_startoff);
        ASSERT(got_endoff >= del_endoff);
 
-       if (isrt)
-               xfs_add_frextents(mp, xfs_rtb_to_rtx(mp, del->br_blockcount));
-
        /*
         * Update the inode delalloc counter now and wait to update the
         * sb counters as we might have to borrow some blocks for the
         * indirect block accounting.
         */
-       ASSERT(!isrt);
        error = xfs_quota_unreserve_blkres(ip, del->br_blockcount);
        if (error)
                return error;
@@ -5019,12 +5016,15 @@ xfs_bmap_del_extent_delay(
 
        ASSERT(da_old >= da_new);
        da_diff = da_old - da_new;
-       if (!isrt)
-               da_diff += del->br_blockcount;
-       if (da_diff) {
-               xfs_add_fdblocks(mp, da_diff);
-               xfs_mod_delalloc(mp, -da_diff);
-       }
+       fdblocks = da_diff;
+
+       if (isrt)
+               xfs_add_frextents(mp, xfs_rtb_to_rtx(mp, del->br_blockcount));
+       else
+               fdblocks += del->br_blockcount;
+
+       xfs_add_fdblocks(mp, fdblocks);
+       xfs_mod_delalloc(mp, -(int64_t)fdblocks);
        return error;
 }