xfs: rework splitting of indirect block reservations

Move the check if we have enough indirect blocks and the stealing of
the deleted extent blocks out of xfs_bmap_split_indlen and into the
caller to prepare for handling delayed allocation of RT extents that
can't easily be stolen.

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 a2b715450ec23ef03ec1afc027d2b6b11ea59fc6..fe33254ca3907411bdba559b4e73af719d02094e 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4831,31 +4831,17 @@ error0:
  * ores == 1). The number of stolen blocks is returned. The availability and
  * subsequent accounting of stolen blocks is the responsibility of the caller.
  */
-static xfs_filblks_t
+static void
 xfs_bmap_split_indlen(
        xfs_filblks_t                   ores,           /* original res. */
        xfs_filblks_t                   *indlen1,       /* ext1 worst indlen */
-       xfs_filblks_t                   *indlen2,       /* ext2 worst indlen */
-       xfs_filblks_t                   avail)          /* stealable blocks */
+       xfs_filblks_t                   *indlen2)       /* ext2 worst indlen */
 {
        xfs_filblks_t                   len1 = *indlen1;
        xfs_filblks_t                   len2 = *indlen2;
        xfs_filblks_t                   nres = len1 + len2; /* new total res. */
-       xfs_filblks_t                   stolen = 0;
        xfs_filblks_t                   resfactor;
 
-       /*
-        * Steal as many blocks as we can to try and satisfy the worst case
-        * indlen for both new extents.
-        */
-       if (ores < nres && avail)
-               stolen = XFS_FILBLKS_MIN(nres - ores, avail);
-       ores += stolen;
-
-        /* nothing else to do if we've satisfied the new reservation */
-       if (ores >= nres)
-               return stolen;
-
        /*
         * We can't meet the total required reservation for the two extents.
         * Calculate the percent of the overall shortage between both extents
@@ -4900,8 +4886,6 @@ xfs_bmap_split_indlen(
 
        *indlen1 = len1;
        *indlen2 = len2;
-
-       return stolen;
 }
 
 int
@@ -4917,7 +4901,7 @@ xfs_bmap_del_extent_delay(
        struct xfs_bmbt_irec    new;
        int64_t                 da_old, da_new, da_diff = 0;
        xfs_fileoff_t           del_endoff, got_endoff;
-       xfs_filblks_t           got_indlen, new_indlen, stolen;
+       xfs_filblks_t           got_indlen, new_indlen, stolen = 0;
        uint32_t                state = xfs_bmap_fork_to_state(whichfork);
        uint64_t                fdblocks;
        int                     error = 0;
@@ -4996,8 +4980,19 @@ xfs_bmap_del_extent_delay(
                new_indlen = xfs_bmap_worst_indlen(ip, new.br_blockcount);
 
                WARN_ON_ONCE(!got_indlen || !new_indlen);
-               stolen = xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen,
-                                                      del->br_blockcount);
+               /*
+                * Steal as many blocks as we can to try and satisfy the worst
+                * case indlen for both new extents.
+                */
+               da_new = got_indlen + new_indlen;
+               if (da_new > da_old) {
+                       stolen = XFS_FILBLKS_MIN(da_new - da_old,
+                                                del->br_blockcount);
+                       da_old += stolen;
+               }
+               if (da_new > da_old)
+                       xfs_bmap_split_indlen(da_old, &got_indlen, &new_indlen);
+               da_new = got_indlen + new_indlen;
 
                got->br_startblock = nullstartblock((int)got_indlen);
 
@@ -5009,7 +5004,6 @@ xfs_bmap_del_extent_delay(
                xfs_iext_next(ifp, icur);
                xfs_iext_insert(ip, icur, &new, state);
 
-               da_new = got_indlen + new_indlen - stolen;
                del->br_blockcount -= stolen;
                break;
        }