[PATCH 4/4] xfs: V5 filesystem format support

[Jan Kara <jack@suse.cz>]

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 | 249 +++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 177 insertions(+), 72 deletions(-)

diff --git a/grub-core/fs/xfs.c b/grub-core/fs/xfs.c
index 7e247a32df5c..7f2582d33e02 100644
--- a/grub-core/fs/xfs.c
+++ b/grub-core/fs/xfs.c
@@ -34,6 +34,15 @@ 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_MOREBITSBIT      0x8000
+
+/* features2 field flags */
+#define XFS_SB_VERSION2_FTYPE           0x00000200      /* inode type in dir */
+
+/* incompat feature flags */
+#define XFS_SB_FEAT_INCOMPAT_FTYPE      (1 << 0)        /* filetype in dirent */
 
 struct grub_xfs_sblock
 {
@@ -45,7 +54,9 @@ 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 +65,19 @@ 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 +85,16 @@ 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 +110,8 @@ 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
@@ -123,17 +144,6 @@ 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;
 
 struct grub_xfs_dirblock_tail
@@ -157,6 +167,8 @@ 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 +176,24 @@ static grub_dl_t my_mod;
 
 \f
 
+static int grub_xfs_sb_hascrc(struct grub_xfs_data *data)
+{
+  return (grub_be_to_cpu16(data->sblock.version) & XFS_SB_VERSION_NUMBITS) == 5;
+}
+
+static int grub_xfs_sb_hasftype(struct grub_xfs_data *data)
+{
+  grub_uint32_t version = grub_be_to_cpu16(data->sblock.version);
+
+  if ((version & XFS_SB_VERSION_NUMBITS) == 5 &&
+      grub_be_to_cpu32(data->sblock.sb_features_incompat) & XFS_SB_FEAT_INCOMPAT_FTYPE)
+    return 1;
+  if (version & XFS_SB_VERSION_MOREBITSBIT &&
+      grub_be_to_cpu32(data->sblock.features2) & XFS_SB_VERSION2_FTYPE)
+    return 1;
+  return 0;
+}
+
 /* Filetype information as used in inodes.  */
 #define FILETYPE_INO_MASK	0170000
 #define FILETYPE_INO_REG	0100000
@@ -219,18 +249,6 @@ 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);
-}
-
 \f
 static inline grub_uint64_t
 grub_xfs_inode_block (struct grub_xfs_data *data,
@@ -261,6 +279,96 @@ grub_xfs_inode_size(struct grub_xfs_data *data)
 	return 1 << data->sblock.log2_inode;
 }
 
+static void *
+grub_xfs_inode_data(struct grub_xfs_inode *inode)
+{
+	if (inode->version <= 2)
+		return ((char *)inode) + 100;
+	return ((char *)inode) + 176;
+}
+
+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 inline int
+grub_xfs_round_dirent_size (int len)
+{
+  return (len + 7) & ~7;
+}
+
+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) + grub_xfs_round_dirent_size (size));
+}
+
+static grub_uint64_t *
+grub_xfs_btree_keys(struct grub_xfs_data *data,
+		    struct grub_xfs_btree_node *leaf)
+{
+  char *p = (char *)(leaf + 1);
+
+  if (data->hascrc)
+    p += 48;	/* crc, uuid, ... */
+  /*
+   * We have to first type to void * to avoid complaints about possible
+   * alignment issues on some architectures
+   */
+  return (grub_uint64_t *)(void *)p;
+}
+
 static grub_err_t
 grub_xfs_read_inode (struct grub_xfs_data *data, grub_uint64_t ino,
 		     struct grub_xfs_inode *inode)
@@ -268,6 +376,9 @@ 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 (%llu) - %llu, %d\n",
+	       (unsigned long long) ino,
+	       (unsigned long long) block, offset);
   /* Read the inode.  */
   if (grub_disk_read (data->disk, block, offset, grub_xfs_inode_size(data),
 		      inode))
@@ -290,6 +401,7 @@ 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;
 
@@ -297,15 +409,15 @@ 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;
@@ -327,7 +439,10 @@ 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");
@@ -335,8 +450,8 @@ 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)));
 	}
@@ -346,7 +461,7 @@ 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
     {
@@ -404,7 +519,7 @@ 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:
       {
@@ -501,23 +616,18 @@ 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))
@@ -526,12 +636,10 @@ 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.  */
@@ -556,10 +664,7 @@ 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;
       }
@@ -586,15 +691,11 @@ 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,
@@ -606,13 +707,11 @@ 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)
@@ -620,14 +719,16 @@ 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), 
@@ -644,8 +745,7 @@ 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);
@@ -670,6 +770,7 @@ 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))
@@ -697,9 +798,13 @@ 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 %llu\n",
+	       (unsigned long long) grub_cpu_to_be64(data->sblock.rootino));
 
   grub_xfs_read_inode (data, data->diropen.ino, &data->diropen.inode);
 
-- 
1.8.1.4