[PATCH v7 10/11] xfs: make the calculation generic in xfs_sb_validate_fsb_count()

Pankaj Raghav (Samsung)
2024-06-07T15:06:24Z

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.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
---
fs/xfs/xfs_mount.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 09eef1721ef4..46cb0384143b 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -132,11 +132,19 @@ xfs_sb_validate_fsb_count(
xfs_sb_t *sbp,
uint64_t nblocks)
{
+ uint64_t max_index;
+ 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)
+ max_index = max_bytes >> PAGE_SHIFT;
+
+ if (max_index > ULONG_MAX)
return -EFBIG;
return 0;
}
--
2.44.1