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

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

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@xxxxxxxxxx>
---
 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
  *