base/SOURCES/0170-xfs-V5-filesystem-format-support.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 1 Jun 2015 14:28:46 +0200
Subject: [PATCH] xfs: V5 filesystem format support

Add support for new XFS on disk format. We have to handle optional
filetype fields in directory entries, additional CRC, LSN, UUID entries
in some structures, etc.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 grub-core/fs/xfs.c | 332 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 252 insertions(+), 80 deletions(-)

diff --git a/grub-core/fs/xfs.c b/grub-core/fs/xfs.c
index 26d8147a92e..f00e43e7dc3 100644
--- a/grub-core/fs/xfs.c
+++ b/grub-core/fs/xfs.c
@@ -34,6 +34,50 @@ GRUB_MOD_LICENSE ("GPLv3+");
 #define XFS_INODE_FORMAT_EXT	2
 #define XFS_INODE_FORMAT_BTREE	3
 
+/* Superblock version field flags */
+#define XFS_SB_VERSION_NUMBITS		0x000f
+#define	XFS_SB_VERSION_ATTRBIT		0x0010
+#define	XFS_SB_VERSION_NLINKBIT		0x0020
+#define	XFS_SB_VERSION_QUOTABIT		0x0040
+#define	XFS_SB_VERSION_ALIGNBIT		0x0080
+#define	XFS_SB_VERSION_DALIGNBIT	0x0100
+#define	XFS_SB_VERSION_LOGV2BIT		0x0400
+#define	XFS_SB_VERSION_SECTORBIT	0x0800
+#define	XFS_SB_VERSION_EXTFLGBIT	0x1000
+#define	XFS_SB_VERSION_DIRV2BIT		0x2000
+#define XFS_SB_VERSION_MOREBITSBIT	0x8000
+#define XFS_SB_VERSION_BITS_SUPPORTED \
+	(XFS_SB_VERSION_NUMBITS | \
+	 XFS_SB_VERSION_ATTRBIT | \
+	 XFS_SB_VERSION_NLINKBIT | \
+	 XFS_SB_VERSION_QUOTABIT | \
+	 XFS_SB_VERSION_ALIGNBIT | \
+	 XFS_SB_VERSION_DALIGNBIT | \
+	 XFS_SB_VERSION_LOGV2BIT | \
+	 XFS_SB_VERSION_SECTORBIT | \
+	 XFS_SB_VERSION_EXTFLGBIT | \
+	 XFS_SB_VERSION_DIRV2BIT | \
+	 XFS_SB_VERSION_MOREBITSBIT)
+
+/* Recognized xfs format versions */
+#define XFS_SB_VERSION_4		4	/* Good old XFS filesystem */
+#define XFS_SB_VERSION_5		5	/* CRC enabled filesystem */
+
+/* features2 field flags */
+#define XFS_SB_VERSION2_LAZYSBCOUNTBIT	0x00000002	/* Superblk counters */
+#define XFS_SB_VERSION2_ATTR2BIT	0x00000008	/* Inline attr rework */
+#define XFS_SB_VERSION2_PROJID32BIT	0x00000080	/* 32-bit project ids */
+#define XFS_SB_VERSION2_FTYPE		0x00000200	/* inode type in dir */
+#define XFS_SB_VERSION2_BITS_SUPPORTED \
+	(XFS_SB_VERSION2_LAZYSBCOUNTBIT | \
+	 XFS_SB_VERSION2_ATTR2BIT | \
+	 XFS_SB_VERSION2_PROJID32BIT | \
+	 XFS_SB_VERSION2_FTYPE)
+
+/* incompat feature flags */
+#define XFS_SB_FEAT_INCOMPAT_FTYPE      (1 << 0)        /* filetype in dirent */
+#define XFS_SB_FEAT_INCOMPAT_SUPPORTED \
+	(XFS_SB_FEAT_INCOMPAT_FTYPE)
 
 struct grub_xfs_sblock
 {
@@ -45,7 +89,9 @@ struct grub_xfs_sblock
   grub_uint64_t rootino;
   grub_uint8_t unused3[20];
   grub_uint32_t agsize;
-  grub_uint8_t unused4[20];
+  grub_uint8_t unused4[12];
+  grub_uint16_t version;
+  grub_uint8_t unused5[6];
   grub_uint8_t label[12];
   grub_uint8_t log2_bsize;
   grub_uint8_t log2_sect;
@@ -54,12 +100,19 @@ struct grub_xfs_sblock
   grub_uint8_t log2_agblk;
   grub_uint8_t unused6[67];
   grub_uint8_t log2_dirblk;
+  grub_uint8_t unused7[7];
+  grub_uint32_t features2;
+  grub_uint8_t unused8[4];
+  grub_uint32_t sb_features_compat;
+  grub_uint32_t sb_features_ro_compat;
+  grub_uint32_t sb_features_incompat;
+  grub_uint32_t sb_features_log_incompat;
 } GRUB_PACKED;
 
 struct grub_xfs_dir_header
 {
   grub_uint8_t count;
-  grub_uint8_t smallino;
+  grub_uint8_t largeino;
   union
   {
     grub_uint32_t i4;
@@ -67,14 +120,16 @@ struct grub_xfs_dir_header
   } GRUB_PACKED parent;
 } GRUB_PACKED;
 
+/* Structure for directory entry inlined in the inode */
 struct grub_xfs_dir_entry
 {
   grub_uint8_t len;
   grub_uint16_t offset;
   char name[1];
-  /* Inode number follows, 32 bits.  */
+  /* Inode number follows, 32 / 64 bits.  */
 } GRUB_PACKED;
 
+/* Structure for directory entry in a block */
 struct grub_xfs_dir2_entry
 {
   grub_uint64_t inode;
@@ -90,7 +145,8 @@ struct grub_xfs_btree_node
   grub_uint16_t numrecs;
   grub_uint64_t left;
   grub_uint64_t right;
-  grub_uint64_t keys[1];
+  /* In V5 here follow crc, uuid, etc. */
+  /* Then follow keys and block pointers */
 }  GRUB_PACKED;
 
 struct grub_xfs_btree_root
@@ -123,19 +179,11 @@ struct grub_xfs_inode
   grub_uint16_t unused3;
   grub_uint8_t fork_offset;
   grub_uint8_t unused4[17];
-  union
-  {
-    char raw[156];
-    struct dir
-    {
-      struct grub_xfs_dir_header dirhead;
-      struct grub_xfs_dir_entry direntry[1];
-    } dir;
-    grub_xfs_extent extents[XFS_INODE_EXTENTS];
-    struct grub_xfs_btree_root btree;
-  } GRUB_PACKED data;
 } GRUB_PACKED;
 
+#define XFS_V2_INODE_SIZE sizeof(struct grub_xfs_inode)
+#define XFS_V3_INODE_SIZE (XFS_V2_INODE_SIZE + 76)
+
 struct grub_xfs_dirblock_tail
 {
   grub_uint32_t leaf_count;
@@ -157,6 +205,8 @@ struct grub_xfs_data
   int pos;
   int bsize;
   grub_uint32_t agsize;
+  unsigned int hasftype:1;
+  unsigned int hascrc:1;
   struct grub_fshelp_node diropen;
 };
 
@@ -164,6 +214,71 @@ static grub_dl_t my_mod;
 
 
 
+static int grub_xfs_sb_hascrc(struct grub_xfs_data *data)
+{
+  return (data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_NUMBITS)) ==
+	  grub_cpu_to_be16_compile_time(XFS_SB_VERSION_5);
+}
+
+static int grub_xfs_sb_hasftype(struct grub_xfs_data *data)
+{
+  if ((data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_NUMBITS)) ==
+	grub_cpu_to_be16_compile_time(XFS_SB_VERSION_5) &&
+      data->sblock.sb_features_incompat & grub_cpu_to_be32_compile_time(XFS_SB_FEAT_INCOMPAT_FTYPE))
+    return 1;
+  if (data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_MOREBITSBIT) &&
+      data->sblock.features2 & grub_cpu_to_be32_compile_time(XFS_SB_VERSION2_FTYPE))
+    return 1;
+  return 0;
+}
+
+static int grub_xfs_sb_valid(struct grub_xfs_data *data)
+{
+  grub_dprintf("xfs", "Validating superblock\n");
+  if (grub_strncmp ((char *) (data->sblock.magic), "XFSB", 4)
+      || data->sblock.log2_bsize < GRUB_DISK_SECTOR_BITS
+      || ((int) data->sblock.log2_bsize
+	  + (int) data->sblock.log2_dirblk) >= 27)
+    {
+      grub_error (GRUB_ERR_BAD_FS, "not a XFS filesystem");
+      return 0;
+    }
+  if ((data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_NUMBITS)) ==
+       grub_cpu_to_be16_compile_time(XFS_SB_VERSION_5))
+    {
+      grub_dprintf("xfs", "XFS v5 superblock detected\n");
+      if (data->sblock.sb_features_incompat &
+          grub_cpu_to_be32_compile_time(~XFS_SB_FEAT_INCOMPAT_SUPPORTED))
+        {
+	  grub_error (GRUB_ERR_BAD_FS, "XFS filesystem has unsupported "
+		      "incompatible features");
+	  return 0;
+        }
+      return 1;
+    }
+  else if ((data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_NUMBITS)) ==
+	   grub_cpu_to_be16_compile_time(XFS_SB_VERSION_4))
+    {
+      grub_dprintf("xfs", "XFS v4 superblock detected\n");
+      if (!(data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_DIRV2BIT)))
+	{
+	  grub_error (GRUB_ERR_BAD_FS, "XFS filesystem without V2 directories "
+		      "is unsupported");
+	  return 0;
+	}
+      if (data->sblock.version & grub_cpu_to_be16_compile_time(~XFS_SB_VERSION_BITS_SUPPORTED) ||
+	  (data->sblock.version & grub_cpu_to_be16_compile_time(XFS_SB_VERSION_MOREBITSBIT) &&
+	   data->sblock.features2 & grub_cpu_to_be16_compile_time(~XFS_SB_VERSION2_BITS_SUPPORTED)))
+	{
+	  grub_error (GRUB_ERR_BAD_FS, "XFS filesystem has unsupported version "
+		      "bits");
+	  return 0;
+	}
+      return 1;
+    }
+  return 0;
+}
+
 /* Filetype information as used in inodes.  */
 #define FILETYPE_INO_MASK	0170000
 #define FILETYPE_INO_REG	0100000
@@ -219,18 +334,6 @@ GRUB_XFS_EXTENT_SIZE (grub_xfs_extent *exts, int ex)
   return (grub_be_to_cpu32 (exts[ex][3]) & ((1 << 21) - 1));
 }
 
-static inline int
-GRUB_XFS_ROUND_TO_DIRENT (int pos)
-{
-  return ((((pos) + 8 - 1) / 8) * 8);
-}
-
-static inline int
-GRUB_XFS_NEXT_DIRENT (int pos, int len)
-{
-  return (pos) + GRUB_XFS_ROUND_TO_DIRENT (8 + 1 + len + 2);
-}
-
 
 static inline grub_uint64_t
 grub_xfs_inode_block (struct grub_xfs_data *data,
@@ -274,6 +377,85 @@ grub_xfs_fshelp_size(struct grub_xfs_data *data)
 	       + grub_xfs_inode_size(data);
 }
 
+static void *
+grub_xfs_inode_data(struct grub_xfs_inode *inode)
+{
+	if (inode->version <= 2)
+		return ((char *)inode) + XFS_V2_INODE_SIZE;
+	return ((char *)inode) + XFS_V3_INODE_SIZE;
+}
+
+static struct grub_xfs_dir_entry *
+grub_xfs_inline_de(struct grub_xfs_dir_header *head)
+{
+	/*
+	 * With small inode numbers the header is 4 bytes smaller because of
+	 * smaller parent pointer
+	 */
+	return (void *)(((char *)head) + sizeof(struct grub_xfs_dir_header) -
+		(head->largeino ? 0 : sizeof(grub_uint32_t)));
+}
+
+static grub_uint8_t *
+grub_xfs_inline_de_inopos(struct grub_xfs_data *data,
+			  struct grub_xfs_dir_entry *de)
+{
+	return ((grub_uint8_t *)(de + 1)) + de->len - 1 +
+		 (data->hasftype ? 1 : 0);
+}
+
+static struct grub_xfs_dir_entry *
+grub_xfs_inline_next_de(struct grub_xfs_data *data,
+			struct grub_xfs_dir_header *head,
+			struct grub_xfs_dir_entry *de)
+{
+  char *p = (char *)de + sizeof(struct grub_xfs_dir_entry) - 1 + de->len;
+
+  p += head->largeino ? sizeof(grub_uint64_t) : sizeof(grub_uint32_t);
+  if (data->hasftype)
+    p++;
+
+  return (struct grub_xfs_dir_entry *)p;
+}
+
+static struct grub_xfs_dirblock_tail *
+grub_xfs_dir_tail(struct grub_xfs_data *data, void *dirblock)
+{
+  int dirblksize = 1 << (data->sblock.log2_bsize + data->sblock.log2_dirblk);
+
+  return (struct grub_xfs_dirblock_tail *)
+    ((char *)dirblock + dirblksize - sizeof (struct grub_xfs_dirblock_tail));
+}
+
+static struct grub_xfs_dir2_entry *
+grub_xfs_first_de(struct grub_xfs_data *data, void *dirblock)
+{
+  if (data->hascrc)
+    return (struct grub_xfs_dir2_entry *)((char *)dirblock + 64);
+  return (struct grub_xfs_dir2_entry *)((char *)dirblock + 16);
+}
+
+static struct grub_xfs_dir2_entry *
+grub_xfs_next_de(struct grub_xfs_data *data, struct grub_xfs_dir2_entry *de)
+{
+  int size = sizeof (struct grub_xfs_dir2_entry) + de->len + 2 /* Tag */;
+
+  if (data->hasftype)
+    size++;		/* File type */
+  return (struct grub_xfs_dir2_entry *)(((char *)de) + ALIGN_UP(size, 8));
+}
+
+static grub_uint64_t *
+grub_xfs_btree_keys(struct grub_xfs_data *data,
+		    struct grub_xfs_btree_node *leaf)
+{
+  grub_uint64_t *keys = (grub_uint64_t *)(leaf + 1);
+
+  if (data->hascrc)
+    keys += 6;	/* skip crc, uuid, ... */
+  return keys;
+}
+
 static grub_err_t
 grub_xfs_read_inode (struct grub_xfs_data *data, grub_uint64_t ino,
 		     struct grub_xfs_inode *inode)
@@ -281,6 +463,8 @@ grub_xfs_read_inode (struct grub_xfs_data *data, grub_uint64_t ino,
   grub_uint64_t block = grub_xfs_inode_block (data, ino);
   int offset = grub_xfs_inode_offset (data, ino);
 
+  grub_dprintf("xfs", "Reading inode (%"PRIuGRUB_UINT64_T") - %"PRIuGRUB_UINT64_T", %d\n",
+	       ino, block, offset);
   /* Read the inode.  */
   if (grub_disk_read (data->disk, block, offset, grub_xfs_inode_size(data),
 		      inode))
@@ -303,6 +487,7 @@ grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
 
   if (node->inode.format == XFS_INODE_FORMAT_BTREE)
     {
+      struct grub_xfs_btree_root *root;
       const grub_uint64_t *keys;
       int recoffset;
 
@@ -310,15 +495,15 @@ grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
       if (leaf == 0)
         return 0;
 
-      nrec = grub_be_to_cpu16 (node->inode.data.btree.numrecs);
-      keys = &node->inode.data.btree.keys[0];
+      root = grub_xfs_inode_data(&node->inode);
+      nrec = grub_be_to_cpu16 (root->numrecs);
+      keys = &root->keys[0];
       if (node->inode.fork_offset)
 	recoffset = (node->inode.fork_offset - 1) / 2;
       else
 	recoffset = (grub_xfs_inode_size(node->data)
-		     - ((char *) &node->inode.data.btree.keys
-			- (char *) &node->inode))
-	  / (2 * sizeof (grub_uint64_t));
+		     - ((char *) keys - (char *) &node->inode))
+				/ (2 * sizeof (grub_uint64_t));
       do
         {
           int i;
@@ -340,7 +525,10 @@ grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
                               0, node->data->bsize, leaf))
             return 0;
 
-          if (grub_strncmp ((char *) leaf->magic, "BMAP", 4))
+	  if ((!node->data->hascrc &&
+	       grub_strncmp ((char *) leaf->magic, "BMAP", 4)) ||
+	      (node->data->hascrc &&
+	       grub_strncmp ((char *) leaf->magic, "BMA3", 4)))
             {
               grub_free (leaf);
               grub_error (GRUB_ERR_BAD_FS, "not a correct XFS BMAP node");
@@ -348,8 +536,8 @@ grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
             }
 
           nrec = grub_be_to_cpu16 (leaf->numrecs);
-          keys = &leaf->keys[0];
-	  recoffset = ((node->data->bsize - ((char *) &leaf->keys
+          keys = grub_xfs_btree_keys(node->data, leaf);
+	  recoffset = ((node->data->bsize - ((char *) keys
 					     - (char *) leaf))
 		       / (2 * sizeof (grub_uint64_t)));
 	}
@@ -359,7 +547,7 @@ grub_xfs_read_block (grub_fshelp_node_t node, grub_disk_addr_t fileblock)
   else if (node->inode.format == XFS_INODE_FORMAT_EXT)
     {
       nrec = grub_be_to_cpu32 (node->inode.nextents);
-      exts = &node->inode.data.extents[0];
+      exts = grub_xfs_inode_data(&node->inode);
     }
   else
     {
@@ -417,7 +605,7 @@ grub_xfs_read_symlink (grub_fshelp_node_t node)
   switch (node->inode.format)
     {
     case XFS_INODE_FORMAT_INO:
-      return grub_strndup (node->inode.data.raw, size);
+      return grub_strndup (grub_xfs_inode_data(&node->inode), size);
 
     case XFS_INODE_FORMAT_EXT:
       {
@@ -512,23 +700,18 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
     {
     case XFS_INODE_FORMAT_INO:
       {
-	struct grub_xfs_dir_entry *de = &diro->inode.data.dir.direntry[0];
-	int smallino = !diro->inode.data.dir.dirhead.smallino;
+	struct grub_xfs_dir_header *head = grub_xfs_inode_data(&diro->inode);
+	struct grub_xfs_dir_entry *de = grub_xfs_inline_de(head);
+	int smallino = !head->largeino;
 	int i;
 	grub_uint64_t parent;
 
 	/* If small inode numbers are used to pack the direntry, the
 	   parent inode number is small too.  */
 	if (smallino)
-	  {
-	    parent = grub_be_to_cpu32 (diro->inode.data.dir.dirhead.parent.i4);
-	    /* The header is a bit smaller than usual.  */
-	    de = (struct grub_xfs_dir_entry *) ((char *) de - 4);
-	  }
+	  parent = grub_be_to_cpu32 (head->parent.i4);
 	else
-	  {
-	    parent = grub_be_to_cpu64(diro->inode.data.dir.dirhead.parent.i8);
-	  }
+	  parent = grub_be_to_cpu64 (head->parent.i8);
 
 	/* Synthesize the direntries for `.' and `..'.  */
 	if (iterate_dir_call_hook (diro->ino, ".", &ctx))
@@ -537,12 +720,10 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 	if (iterate_dir_call_hook (parent, "..", &ctx))
 	  return 1;
 
-	for (i = 0; i < diro->inode.data.dir.dirhead.count; i++)
+	for (i = 0; i < head->count; i++)
 	  {
 	    grub_uint64_t ino;
-	    grub_uint8_t *inopos = (((grub_uint8_t *) de)
-			    + sizeof (struct grub_xfs_dir_entry)
-			    + de->len - 1);
+	    grub_uint8_t *inopos = grub_xfs_inline_de_inopos(dir->data, de);
 	    grub_uint8_t c;
 
 	    /* inopos might be unaligned.  */
@@ -567,10 +748,7 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 	      return 1;
 	    de->name[de->len] = c;
 
-	    de = ((struct grub_xfs_dir_entry *)
-		  (((char *) de)+ sizeof (struct grub_xfs_dir_entry) + de->len
-		   + ((smallino ? sizeof (grub_uint32_t)
-		       : sizeof (grub_uint64_t))) - 1));
+	    de = grub_xfs_inline_next_de(dir->data, head, de);
 	  }
 	break;
       }
@@ -597,15 +775,11 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 		    >> dirblk_log2);
 	     blk++)
 	  {
-	    /* The header is skipped, the first direntry is stored
-	       from byte 16.  */
-	    int pos = 16;
+	    struct grub_xfs_dir2_entry *direntry =
+					grub_xfs_first_de(dir->data, dirblock);
 	    int entries;
-	    int tail_start = (dirblk_size
-			      - sizeof (struct grub_xfs_dirblock_tail));
-
-	    struct grub_xfs_dirblock_tail *tail;
-	    tail = (struct grub_xfs_dirblock_tail *) &dirblock[tail_start];
+	    struct grub_xfs_dirblock_tail *tail =
+					grub_xfs_dir_tail(dir->data, dirblock);
 
 	    numread = grub_xfs_read_file (dir, 0, 0,
 					  blk << dirblk_log2,
@@ -617,13 +791,11 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 		       - grub_be_to_cpu32 (tail->leaf_stale));
 
 	    /* Iterate over all entries within this block.  */
-	    while (pos < tail_start)
+	    while ((char *)direntry < (char *)tail)
 	      {
-		struct grub_xfs_dir2_entry *direntry;
 		grub_uint8_t *freetag;
 		char *filename;
 
-		direntry = (struct grub_xfs_dir2_entry *) &dirblock[pos];
 		freetag = (grub_uint8_t *) direntry;
 
 		if (grub_get_unaligned16 (freetag) == 0XFFFF)
@@ -631,14 +803,16 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 		    grub_uint8_t *skip = (freetag + sizeof (grub_uint16_t));
 
 		    /* This entry is not used, go to the next one.  */
-		    pos += grub_be_to_cpu16 (grub_get_unaligned16 (skip));
+		    direntry = (struct grub_xfs_dir2_entry *)
+				(((char *)direntry) +
+				grub_be_to_cpu16 (grub_get_unaligned16 (skip)));
 
 		    continue;
 		  }
 
-		filename = &dirblock[pos + sizeof (*direntry)];
-		/* The byte after the filename is for the tag, which
-		   is not used by GRUB.  So it can be overwritten.  */
+		filename = (char *)(direntry + 1);
+		/* The byte after the filename is for the filetype, padding, or
+		   tag, which is not used by GRUB.  So it can be overwritten. */
 		filename[direntry->len] = '\0';
 
 		if (iterate_dir_call_hook (grub_be_to_cpu64(direntry->inode), 
@@ -655,8 +829,7 @@ grub_xfs_iterate_dir (grub_fshelp_node_t dir,
 		  break;
 
 		/* Select the next directory entry.  */
-		pos = GRUB_XFS_NEXT_DIRENT (pos, direntry->len);
-		pos = GRUB_XFS_ROUND_TO_DIRENT (pos);
+		direntry = grub_xfs_next_de(dir->data, direntry);
 	      }
 	  }
 	grub_free (dirblock);
@@ -681,19 +854,14 @@ grub_xfs_mount (grub_disk_t disk)
   if (!data)
     return 0;
 
+  grub_dprintf("xfs", "Reading sb\n");
   /* Read the superblock.  */
   if (grub_disk_read (disk, 0, 0,
 		      sizeof (struct grub_xfs_sblock), &data->sblock))
     goto fail;
 
-  if (grub_strncmp ((char *) (data->sblock.magic), "XFSB", 4)
-      || data->sblock.log2_bsize < GRUB_DISK_SECTOR_BITS
-      || ((int) data->sblock.log2_bsize
-	  + (int) data->sblock.log2_dirblk) >= 27)
-    {
-      grub_error (GRUB_ERR_BAD_FS, "not a XFS filesystem");
-      goto fail;
-    }
+  if (!grub_xfs_sb_valid(data))
+    goto fail;
 
   data = grub_realloc (data,
 		       sizeof (struct grub_xfs_data)
@@ -708,9 +876,13 @@ grub_xfs_mount (grub_disk_t disk)
   data->diropen.inode_read = 1;
   data->bsize = grub_be_to_cpu32 (data->sblock.bsize);
   data->agsize = grub_be_to_cpu32 (data->sblock.agsize);
+  data->hasftype = grub_xfs_sb_hasftype(data);
+  data->hascrc = grub_xfs_sb_hascrc(data);
 
   data->disk = disk;
   data->pos = 0;
+  grub_dprintf("xfs", "Reading root ino %"PRIuGRUB_UINT64_T"\n",
+	       grub_cpu_to_be64(data->sblock.rootino));
 
   grub_xfs_read_inode (data, data->diropen.ino, &data->diropen.inode);