4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Christoph Hellwig <h...@lst.de>
commit 12ef830198b0d71668eb9b59f9ba69d32951a48a upstream.
->total is a bit of an odd parameter passed down to the low-level
allocator all the way from the high-level callers. It's supposed to
contain the maximum number of blocks to be allocated for the whole
transaction [1].
But in xfs_iomap_write_allocate we only convert existing delayed
allocations and thus only have a minimal block reservation for the
current transaction, so xfs_alloc_space_available can't use it for
the allocation decisions. Use the maximum of args->total and the
calculated block requirement to make a decision. We probably should
get rid of args->total eventually and instead apply ->minleft more
broadly, but that will require some extensive changes all over.
[1] which creates lots of confusion as most callers don't decrement it
once doing a first allocation. But that's for a separate series.
Signed-off-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Brian Foster <bfos...@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.w...@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/xfs/libxfs/xfs_alloc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1995,7 +1995,7 @@ xfs_alloc_space_available(
int flags)
{
struct xfs_perag *pag = args->pag;
- xfs_extlen_t longest;
+ xfs_extlen_t alloc_len, longest;
xfs_extlen_t reservation; /* blocks that are still reserved
*/
int available;
@@ -2005,15 +2005,16 @@ xfs_alloc_space_available(
reservation = xfs_ag_resv_needed(pag, args->resv);
/* do we have enough contiguous free space for the allocation? */
+ alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop;
longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free,
reservation);
- if ((args->minlen + args->alignment + args->minalignslop - 1) > longest)
+ if (longest < alloc_len)
return false;
/* do we have enough free space remaining for the allocation? */
available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
reservation - min_free - args->minleft);
- if (available < (int)args->total)
+ if (available < (int)max(args->total, alloc_len))
return false;
/*
