xfs: allocate sparse inode chunks on full chunk allocation failure

xfs_ialloc_ag_alloc() makes several attempts to allocate a full inode
chunk. If all else fails, reduce the allocation to the sparse length and
alignment and attempt to allocate a sparse inode chunk.

If sparse chunk allocation succeeds, check whether an inobt record
already exists that can track the chunk. If so, inherit and update the
existing record. Otherwise, insert a new record for the sparse chunk.

Create helpers to align sparse chunk inode records and insert or update
existing records in the inode btrees. The xfs_inobt_insert_sprec()
helper implements the merge or update semantics required for sparse
inode records with respect to both the inobt and finobt. To update the
inobt, either insert a new record or merge with an existing record. To
update the finobt, use the updated inobt record to either insert or
replace an existing record.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.h b/fs/xfs/libxfs/xfs_ialloc_btree.h
index 2c581ba69cde..bd88453217ce 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.h
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.h
@@ -65,4 +65,11 @@ extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
 /* ir_holemask to inode allocation bitmap conversion */
 uint64_t xfs_inobt_irec_to_allocmask(struct xfs_inobt_rec_incore *);
 
+#if defined(DEBUG) || defined(XFS_WARN)
+int xfs_inobt_rec_check_count(struct xfs_mount *,
+			      struct xfs_inobt_rec_incore *);
+#else
+#define xfs_inobt_rec_check_count(mp, rec)	0
+#endif	/* DEBUG */
+
 #endif	/* __XFS_IALLOC_BTREE_H__ */