[PATCH v6 05/18] xfs: use sparse chunk alignment for min. inode allocation requirement

Brian Foster
2015-03-02T13:28:12Z

xfs_ialloc_ag_select() iterates through the allocation groups looking
for free inodes or free space to determine whether to allow an inode
allocation to proceed. If no free inodes are available, it assumes that
an AG must have an extent longer than mp->m_ialloc_blks.

Sparse inode chunk support currently allows for allocations smaller than
the traditional inode chunk size specified in m_ialloc_blks. The current
minimum sparse allocation is set in the superblock sb_spino_align field
at mkfs time. Create a new m_ialloc_min_blks field in xfs_mount and use
this to represent the minimum supported allocation size for inode
chunks. Initialize m_ialloc_min_blks at mount time based on whether
sparse inodes are supported.

Signed-off-by: Brian Foster <bfoster@redhat.com>
---
fs/xfs/libxfs/xfs_ialloc.c | 2 +-
fs/xfs/libxfs/xfs_sb.c | 5 +++++
fs/xfs/xfs_mount.h | 2 ++
3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 3033099..269d9ca 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -645,7 +645,7 @@ xfs_ialloc_ag_select(
* if we fail allocation due to alignment issues then it is most
* likely a real ENOSPC condition.
*/
- ineed = mp->m_ialloc_blks;
+ ineed = mp->m_ialloc_min_blks;
if (flags && ineed > 1)
ineed += xfs_ialloc_cluster_alignment(mp);
longest = pag->pagf_longest;
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 32739a3..da11992 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -689,6 +689,11 @@ xfs_sb_mount_common(
mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
sbp->sb_inopblock);
mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
+
+ if (sbp->sb_spino_align)
+ mp->m_ialloc_min_blks = sbp->sb_spino_align;
+ else
+ mp->m_ialloc_min_blks = mp->m_ialloc_blks;
}

/*
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 8c995a2..df209c2 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -101,6 +101,8 @@ typedef struct xfs_mount {
__uint64_t m_flags; /* global mount flags */
int m_ialloc_inos; /* inodes in inode allocation */
int m_ialloc_blks; /* blocks in inode allocation */
+ int m_ialloc_min_blks;/* min blocks in sparse inode
+ * allocation */
int m_inoalign_mask;/* mask sb_inoalignmt if used */
uint m_qflags; /* quota status flags */
struct xfs_trans_resv m_resv; /* precomputed res values */