[PATCH 1/3] xfs: move kernel-specific superblock validation out of libxfs

Darrick J. Wong
2020-12-01T03:38:20Z

From: Darrick J. Wong <darrick.wong@oracle.com>

A couple of the superblock validation checks apply only to the kernel,
so move them to xfs_mount.c before we start changing sb_inprogress.
This also reduces the diff between kernel and userspace libxfs.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_sb.c | 23 ++++-------------------
fs/xfs/libxfs/xfs_sb.h | 3 +++
fs/xfs/xfs_mount.c | 31 +++++++++++++++++++++++++++++++
3 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 5aeafa59ed27..a2c43fe38f64 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -223,6 +223,7 @@ xfs_validate_sb_common(
struct xfs_dsb *dsb = bp->b_addr;
uint32_t agcount = 0;
uint32_t rem;
+ int error;

if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
xfs_warn(mp, "bad magic number");
@@ -382,16 +383,9 @@ xfs_validate_sb_common(
return -EFSCORRUPTED;
}

- /*
- * Until this is fixed only page-sized or smaller data blocks work.
- */
- if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
- xfs_warn(mp,
- "File system with blocksize %d bytes. "
- "Only pagesize (%ld) or less will currently work.",
- sbp->sb_blocksize, PAGE_SIZE);
- return -ENOSYS;
- }
+ error = xfs_sb_validate_mount(mp, bp, sbp);
+ if (error)
+ return error;

/*
* Currently only very few inode sizes are supported.
@@ -415,15 +409,6 @@ xfs_validate_sb_common(
return -EFBIG;
}

- /*
- * Don't touch the filesystem if a user tool thinks it owns the primary
- * superblock. mkfs doesn't clear the flag from secondary supers, so
- * we don't check them at all.
- */
- if (XFS_BUF_ADDR(bp) == XFS_SB_DADDR && sbp->sb_inprogress) {
- xfs_warn(mp, "Offline file system operation in progress!");
- return -EFSCORRUPTED;
- }
return 0;
}

diff --git a/fs/xfs/libxfs/xfs_sb.h b/fs/xfs/libxfs/xfs_sb.h
index 92465a9a5162..ee0a5858dd47 100644
--- a/fs/xfs/libxfs/xfs_sb.h
+++ b/fs/xfs/libxfs/xfs_sb.h
@@ -42,4 +42,7 @@ extern int xfs_sb_get_secondary(struct xfs_mount *mp,
struct xfs_trans *tp, xfs_agnumber_t agno,
struct xfs_buf **bpp);

+int xfs_sb_validate_mount(struct xfs_mount *mp, struct xfs_buf *bp,
+ struct xfs_sb *sbp);
+
#endif /* __XFS_SB_H__ */
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 7110507a2b6b..7bc7901d648d 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -259,6 +259,37 @@ xfs_initialize_perag(
return error;
}

+/* Validate the superblock is compatible with this mount. */
+int
+xfs_sb_validate_mount(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp,
+ struct xfs_sb *sbp)
+{
+ /*
+ * Don't touch the filesystem if a user tool thinks it owns the primary
+ * superblock. mkfs doesn't clear the flag from secondary supers, so
+ * we don't check them at all.
+ */
+ if (XFS_BUF_ADDR(bp) == XFS_SB_DADDR && sbp->sb_inprogress) {
+ xfs_warn(mp, "Offline file system operation in progress!");
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Until this is fixed only page-sized or smaller data blocks work.
+ */
+ if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
+ xfs_warn(mp,
+ "File system with blocksize %d bytes. "
+ "Only pagesize (%ld) or less will currently work.",
+ sbp->sb_blocksize, PAGE_SIZE);
+ return -ENOSYS;
+ }
+
+ return 0;
+}
+
/*
* xfs_readsb
*