xfs: update free inode record logic to support sparse inode records

xfs_difree_inobt() uses logic in a couple places that assume inobt
records refer to fully allocated chunks. Specifically, the use of
mp->m_ialloc_inos can cause problems for inode chunks that are sparsely
allocated. Sparse inode chunks can, by definition, define a smaller
number of inodes than a full inode chunk.

Fix the logic that determines whether an inode record should be removed
from the inobt to use the ir_free mask rather than ir_freecount. Fix the
agi counters modification to use ir_freecount to add the actual number
of inodes freed rather than assuming a full inode chunk.

Also make sure that we preserve the behavior to not remove inode chunks
if the block size is large enough for multiple inode chunks (e.g.,
bsize=64k, isize=512). This behavior was previously implicit in that in
such configurations, ir.freecount of a single record never matches
m_ialloc_inos. Hence, add some comments as well.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Brian Foster 2015-05-29 08:51:37 +10:00 committed by Dave Chinner
parent d4cc540b08
commit 999633d304

View file

@ -1508,10 +1508,13 @@ xfs_difree_inobt(
rec.ir_freecount++; rec.ir_freecount++;
/* /*
* When an inode cluster is free, it becomes eligible for removal * When an inode chunk is free, it becomes eligible for removal. Don't
* remove the chunk if the block size is large enough for multiple inode
* chunks (that might not be free).
*/ */
if (!(mp->m_flags & XFS_MOUNT_IKEEP) && if (!(mp->m_flags & XFS_MOUNT_IKEEP) &&
(rec.ir_freecount == mp->m_ialloc_inos)) { rec.ir_free == XFS_INOBT_ALL_FREE &&
mp->m_sb.sb_inopblock <= XFS_INODES_PER_CHUNK) {
*deleted = 1; *deleted = 1;
*first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino); *first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
@ -1521,7 +1524,7 @@ xfs_difree_inobt(
* AGI and Superblock inode counts, and mark the disk space * AGI and Superblock inode counts, and mark the disk space
* to be freed when the transaction is committed. * to be freed when the transaction is committed.
*/ */
ilen = mp->m_ialloc_inos; ilen = rec.ir_freecount;
be32_add_cpu(&agi->agi_count, -ilen); be32_add_cpu(&agi->agi_count, -ilen);
be32_add_cpu(&agi->agi_freecount, -(ilen - 1)); be32_add_cpu(&agi->agi_freecount, -(ilen - 1));
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT); xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
@ -1641,8 +1644,13 @@ xfs_difree_finobt(
* free inode. Hence, if all of the inodes are free and we aren't * free inode. Hence, if all of the inodes are free and we aren't
* keeping inode chunks permanently on disk, remove the record. * keeping inode chunks permanently on disk, remove the record.
* Otherwise, update the record with the new information. * Otherwise, update the record with the new information.
*
* Note that we currently can't free chunks when the block size is large
* enough for multiple chunks. Leave the finobt record to remain in sync
* with the inobt.
*/ */
if (rec.ir_freecount == mp->m_ialloc_inos && if (rec.ir_free == XFS_INOBT_ALL_FREE &&
mp->m_sb.sb_inopblock <= XFS_INODES_PER_CHUNK &&
!(mp->m_flags & XFS_MOUNT_IKEEP)) { !(mp->m_flags & XFS_MOUNT_IKEEP)) {
error = xfs_btree_delete(cur, &i); error = xfs_btree_delete(cur, &i);
if (error) if (error)