[PATCH v9 09/10] xfs: make the calculation generic in xfs_sb_validate_fsb_count()

Pankaj Raghav (Samsung)
2024-07-04T11:24:05Z

From: Pankaj Raghav <p.raghav@samsung.com>

Instead of assuming that PAGE_SHIFT is always higher than the blocklog,
make the calculation generic so that page cache count can be calculated
correctly for LBS.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_mount.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 09eef1721ef4f..3949f720b5354 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -132,11 +132,16 @@ xfs_sb_validate_fsb_count(
xfs_sb_t *sbp,
uint64_t nblocks)
{
+ uint64_t max_bytes;
+
ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
ASSERT(sbp->sb_blocklog >= BBSHIFT);

+ if (check_shl_overflow(nblocks, sbp->sb_blocklog, &max_bytes))
+ return -EFBIG;
+
/* Limited by ULONG_MAX of page cache index */
- if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
+ if (max_bytes >> PAGE_SHIFT > ULONG_MAX)
return -EFBIG;
return 0;
}
--
2.44.1