xfs: use per-AG reservations for the finobt
Currently we try to rely on the global reserved block pool for block
allocations for the free inode btree, but I have customer reports
(fairly complex workload, need to find an easier reproducer) where that
is not enough as the AG where we free an inode that requires a new
finobt block is entirely full. This causes us to cancel a dirty
transaction and thus a file system shutdown.
I think the right way to guard against this is to treat the finot the same
way as the refcount btree and have a per-AG reservations for the possible
worst case size of it, and the patch below implements that.
Note that this could increase mount times with large finobt trees. In
an ideal world we would have added a field for the number of finobt
fields to the AGI, similar to what we did for the refcount blocks.
We should do add it next time we rev the AGI or AGF format by adding
new fields.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index 0fd086d..7c47188 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -82,11 +82,12 @@ xfs_finobt_set_root(
}
STATIC int
-xfs_inobt_alloc_block(
+__xfs_inobt_alloc_block(
struct xfs_btree_cur *cur,
union xfs_btree_ptr *start,
union xfs_btree_ptr *new,
- int *stat)
+ int *stat,
+ enum xfs_ag_resv_type resv)
{
xfs_alloc_arg_t args; /* block allocation args */
int error; /* error return value */
@@ -103,6 +104,7 @@ xfs_inobt_alloc_block(
args.maxlen = 1;
args.prod = 1;
args.type = XFS_ALLOCTYPE_NEAR_BNO;
+ args.resv = resv;
error = xfs_alloc_vextent(&args);
if (error) {
@@ -123,6 +125,27 @@ xfs_inobt_alloc_block(
}
STATIC int
+xfs_inobt_alloc_block(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *start,
+ union xfs_btree_ptr *new,
+ int *stat)
+{
+ return __xfs_inobt_alloc_block(cur, start, new, stat, XFS_AG_RESV_NONE);
+}
+
+STATIC int
+xfs_finobt_alloc_block(
+ struct xfs_btree_cur *cur,
+ union xfs_btree_ptr *start,
+ union xfs_btree_ptr *new,
+ int *stat)
+{
+ return __xfs_inobt_alloc_block(cur, start, new, stat,
+ XFS_AG_RESV_METADATA);
+}
+
+STATIC int
xfs_inobt_free_block(
struct xfs_btree_cur *cur,
struct xfs_buf *bp)
@@ -328,7 +351,7 @@ static const struct xfs_btree_ops xfs_finobt_ops = {
.dup_cursor = xfs_inobt_dup_cursor,
.set_root = xfs_finobt_set_root,
- .alloc_block = xfs_inobt_alloc_block,
+ .alloc_block = xfs_finobt_alloc_block,
.free_block = xfs_inobt_free_block,
.get_minrecs = xfs_inobt_get_minrecs,
.get_maxrecs = xfs_inobt_get_maxrecs,
@@ -480,3 +503,64 @@ xfs_inobt_rec_check_count(
return 0;
}
#endif /* DEBUG */
+
+static xfs_extlen_t
+xfs_inobt_max_size(
+ struct xfs_mount *mp)
+{
+ /* Bail out if we're uninitialized, which can happen in mkfs. */
+ if (mp->m_inobt_mxr[0] == 0)
+ return 0;
+
+ return xfs_btree_calc_size(mp, mp->m_inobt_mnr,
+ (uint64_t)mp->m_sb.sb_agblocks * mp->m_sb.sb_inopblock /
+ XFS_INODES_PER_CHUNK);
+}
+
+static int
+xfs_inobt_count_blocks(
+ struct xfs_mount *mp,
+ xfs_agnumber_t agno,
+ xfs_btnum_t btnum,
+ xfs_extlen_t *tree_blocks)
+{
+ struct xfs_buf *agbp;
+ struct xfs_btree_cur *cur;
+ int error;
+
+ error = xfs_ialloc_read_agi(mp, NULL, agno, &agbp);
+ if (error)
+ return error;
+
+ cur = xfs_inobt_init_cursor(mp, NULL, agbp, agno, btnum);
+ error = xfs_btree_count_blocks(cur, tree_blocks);
+ xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+ xfs_buf_relse(agbp);
+
+ return error;
+}
+
+/*
+ * Figure out how many blocks to reserve and how many are used by this btree.
+ */
+int
+xfs_finobt_calc_reserves(
+ struct xfs_mount *mp,
+ xfs_agnumber_t agno,
+ xfs_extlen_t *ask,
+ xfs_extlen_t *used)
+{
+ xfs_extlen_t tree_len = 0;
+ int error;
+
+ if (!xfs_sb_version_hasfinobt(&mp->m_sb))
+ return 0;
+
+ error = xfs_inobt_count_blocks(mp, agno, XFS_BTNUM_FINO, &tree_len);
+ if (error)
+ return error;
+
+ *ask += xfs_inobt_max_size(mp);
+ *used += tree_len;
+ return 0;
+}