[RFC v2 12/14] xfs: make the calculation generic in xfs_sb_validate_fsb_count()

Pankaj Raghav (Samsung)
2024-02-13T09:38:05Z

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>
---
fs/xfs/xfs_mount.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index aabb25dc3efa..bfbaaecaf668 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -133,9 +133,13 @@ xfs_sb_validate_fsb_count(
{
ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
ASSERT(sbp->sb_blocklog >= BBSHIFT);
+ unsigned long mapping_count;
+ uint64_t bytes = nblocks << sbp->sb_blocklog;
+
+ mapping_count = bytes >> PAGE_SHIFT;

/* Limited by ULONG_MAX of page cache index */
- if (nblocks >> (PAGE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
+ if (mapping_count > ULONG_MAX)
return -EFBIG;
return 0;
}
--
2.43.0