From: Dave Chinner dchinner@redhat.com
maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9VTE3 CVE: NA
Reference: https://lore.kernel.org/linux-xfs/20240705162450.3481169-1-john.g.garry@orac...
--------------------------------
If args->minlen is not aligned to the constraints of forced alignment, we may do minlen allocations that are not aligned when we approach ENOSPC. Avoid this by always aligning args->minlen appropriately. If alignment of minlen results in a value smaller than the alignment constraint, fail the allocation immediately.
Signed-off-by: Dave Chinner dchinner@redhat.com Reviewed-by: "Darrick J. Wong" djwong@kernel.org Signed-off-by: John Garry john.g.garry@oracle.com Conflicts: fs/xfs/libxfs/xfs_bmap.c [Conflicts in xfs_bmap_select_minlen()] Signed-off-by: Long Li leo.lilong@huawei.com --- fs/xfs/libxfs/xfs_bmap.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 7682dfe2f701..1cb4fe414e55 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3253,32 +3253,44 @@ xfs_bmap_longest_free_extent( return error; }
-static void +static int xfs_bmap_select_minlen( struct xfs_bmalloca *ap, struct xfs_alloc_arg *args, xfs_extlen_t *blen, int notinit) { + xfs_extlen_t nlen = 0; + if (notinit || *blen < ap->minlen) { /* * Since we did a BUF_TRYLOCK above, it is possible that * there is space for this request. */ - args->minlen = ap->minlen; + nlen = ap->minlen; } else if (*blen < args->maxlen) { /* * If the best seen length is less than the request length, * use the best as the minimum. */ - args->minlen = *blen; + + nlen = *blen; } else { /* * Otherwise we've seen an extent as big as maxlen, use that * as the minimum. */ - args->minlen = args->maxlen; + nlen = args->maxlen; } + + if (args->alignment > 1) { + nlen = rounddown(nlen, args->alignment); + if (nlen < ap->minlen) { + return -ENOSPC; + } + } + args->minlen = nlen; + return 0; }
STATIC int @@ -3311,8 +3323,8 @@ xfs_bmap_btalloc_nullfb( break; }
- xfs_bmap_select_minlen(ap, args, blen, notinit); - return 0; + error = xfs_bmap_select_minlen(ap, args, blen, notinit); + return error; }
STATIC int @@ -3349,7 +3361,9 @@ xfs_bmap_btalloc_filestreams(
}
- xfs_bmap_select_minlen(ap, args, blen, notinit); + error = xfs_bmap_select_minlen(ap, args, blen, notinit); + if (error) + return error;
/* * Set the failure fallback case to look in the selected AG as stream