diff options
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 46 |
1 files changed, 36 insertions, 10 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 6de613b558a9..2a43d5c7fde5 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -4727,22 +4727,39 @@ error0: * * Given the original reservation and the worst case indlen for the two new * extents (as calculated by xfs_bmap_worst_indlen()), split the original - * reservation fairly across the two new extents. + * reservation fairly across the two new extents. If necessary, steal available + * blocks from a deleted extent to make up a reservation deficiency (e.g., if + * ores == 1). The number of stolen blocks is returned. The availability and + * subsequent accounting of stolen blocks is the responsibility of the caller. */ -static void +static xfs_filblks_t 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 *indlen2, /* ext2 worst indlen */ + xfs_filblks_t avail) /* stealable blocks */ { xfs_filblks_t len1 = *indlen1; xfs_filblks_t len2 = *indlen2; xfs_filblks_t nres = len1 + len2; /* new total res. */ + xfs_filblks_t stolen = 0; + + /* + * Steal as many blocks as we can to try and satisfy the worst case + * indlen for both new extents. + */ + while (nres > ores && avail) { + nres--; + avail--; + stolen++; + } /* - * The only blocks available are those reserved for the original extent. - * Therefore, we have to skim blocks off each of the new reservations so - * long as the new total reservation is greater than the original. + * The only blocks available are those reserved for the original + * extent and what we can steal from the extent being removed. + * If this still isn't enough to satisfy the combined + * requirements for the two new extents, skim blocks off of each + * of the new reservations until they match what is available. */ while (nres > ores) { if (len1) { @@ -4759,6 +4776,8 @@ xfs_bmap_split_indlen( *indlen1 = len1; *indlen2 = len2; + + return stolen; } /* @@ -5025,20 +5044,27 @@ xfs_bmap_del_extent( XFS_IFORK_NEXT_SET(ip, whichfork, XFS_IFORK_NEXTENTS(ip, whichfork) + 1); } else { + xfs_filblks_t stolen; ASSERT(whichfork == XFS_DATA_FORK); /* * Distribute the original indlen reservation across the - * two new extents. + * two new extents. Steal blocks from the deleted extent + * if necessary. Stealing blocks simply fudges the + * fdblocks accounting in xfs_bunmapi(). */ temp = xfs_bmap_worst_indlen(ip, got.br_blockcount); temp2 = xfs_bmap_worst_indlen(ip, new.br_blockcount); - xfs_bmap_split_indlen(da_old, &temp, &temp2); - da_new = temp + temp2; + stolen = xfs_bmap_split_indlen(da_old, &temp, &temp2, + del->br_blockcount); + da_new = temp + temp2 - stolen; + del->br_blockcount -= stolen; /* - * Set the reservation for each extent. + * Set the reservation for each extent. Warn if either + * is zero as this can lead to delalloc problems. */ + WARN_ON_ONCE(!temp || !temp2); xfs_bmbt_set_startblock(ep, nullstartblock((int)temp)); new.br_startblock = nullstartblock((int)temp2); } |