xfs: add a define for statfs magic to uapi

Needed by userspace programs that call fstatfs(). It'd be natural to publish XFS_SB_MAGIC in uapi, but while these two have identical values, they have different semantic meaning: one is an enum cookie meant for statfs, the other a signature of the on-disk format. Signed-off-by: Adam Borowski <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Dave Chinner <[email protected]>
tadfisher · Oct 18, 2018 · dddde68 · dddde68
1 parent 4831822
commit dddde68
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
@@ -43,6 +43,7 @@
 #include <linux/dax.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/magic.h>
 #include <linux/mount.h>
 #include <linux/mempool.h>
 #include <linux/writeback.h>
@@ -1128,7 +1129,7 @@ xfs_fs_statfs(
 	xfs_extlen_t		lsize;
 	int64_t			ffree;
 
-	statp->f_type = XFS_SB_MAGIC;
+	statp->f_type = XFS_SUPER_MAGIC;
 	statp->f_namelen = MAXNAMELEN - 1;
 
 	id = huge_encode_dev(mp->m_ddev_targp->bt_dev);
@@ -1681,7 +1682,7 @@ xfs_fs_fill_super(
 	 * we must configure the block size in the superblock before we run the
 	 * full mount process as the mount process can lookup and cache inodes.
 	 */
-	sb->s_magic = XFS_SB_MAGIC;
+	sb->s_magic = XFS_SUPER_MAGIC;
 	sb->s_blocksize = mp->m_sb.sb_blocksize;
 	sb->s_blocksize_bits = ffs(sb->s_blocksize) - 1;
 	sb->s_maxbytes = xfs_max_file_offset(sb->s_blocksize_bits);

diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h
@@ -29,6 +29,7 @@
 #define HPFS_SUPER_MAGIC	0xf995e849
 #define ISOFS_SUPER_MAGIC	0x9660
 #define JFFS2_SUPER_MAGIC	0x72b6
+#define XFS_SUPER_MAGIC		0x58465342	/* "XFSB" */
 #define PSTOREFS_MAGIC		0x6165676C
 #define EFIVARFS_MAGIC		0xde5e81e4
 #define HOSTFS_SUPER_MAGIC	0x00c0ffee