xfs: add support for large btree blocks

Add support for larger btree blocks that contains a CRC32C checksum,
a filesystem uuid and block number for detecting filesystem
consistency and out of place writes.

[dchinner@redhat.com] Also include an owner field to allow reverse
mappings to be implemented for improved repairability and a LSN
field to so that log recovery can easily determine the last
modification that made it to disk for each buffer.

[dchinner@redhat.com] Add buffer log format flags to indicate the
type of buffer to recovery so that we don't have to do blind magic
number tests to determine what the buffer is.

[dchinner@redhat.com] Modified to fit into the verifier structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 211 insertions, 45 deletions

diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index db010408d70..ec77036f13b 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -30,9 +30,11 @@
 #include "xfs_dinode.h"
 #include "xfs_inode.h"
 #include "xfs_inode_item.h"
+#include "xfs_buf_item.h"
 #include "xfs_btree.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
+#include "xfs_cksum.h"
 
 /*
  * Cursor allocation zone.
@@ -42,9 +44,13 @@ kmem_zone_t	*xfs_btree_cur_zone;
 /*
  * Btree magic numbers.
  */
-const __uint32_t xfs_magics[XFS_BTNUM_MAX] = {
-	XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC
+static const __uint32_t xfs_magics[2][XFS_BTNUM_MAX] = {
+	{ XFS_ABTB_MAGIC, XFS_ABTC_MAGIC, XFS_BMAP_MAGIC, XFS_IBT_MAGIC },
+	{ XFS_ABTB_CRC_MAGIC, XFS_ABTC_CRC_MAGIC,
+	  XFS_BMAP_CRC_MAGIC, XFS_IBT_CRC_MAGIC }
 };
+#define xfs_btree_magic(cur) \
+	xfs_magics[!!((cur)->bc_flags & XFS_BTREE_CRC_BLOCKS)][cur->bc_btnum]
 
 
 STATIC int				/* error (0 or EFSCORRUPTED) */
@@ -54,30 +60,38 @@ xfs_btree_check_lblock(
 	int			level,	/* level of the btree block */
 	struct xfs_buf		*bp)	/* buffer for block, if any */
 {
-	int			lblock_ok; /* block passes checks */
+	int			lblock_ok = 1; /* block passes checks */
 	struct xfs_mount	*mp;	/* file system mount point */
 
 	mp = cur->bc_mp;
-	lblock_ok =
-		be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
+
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		lblock_ok = lblock_ok &&
+			uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid) &&
+			block->bb_u.l.bb_blkno == cpu_to_be64(
+				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+	}
+
+	lblock_ok = lblock_ok &&
+		be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
 		be16_to_cpu(block->bb_level) == level &&
 		be16_to_cpu(block->bb_numrecs) <=
 			cur->bc_ops->get_maxrecs(cur, level) &&
 		block->bb_u.l.bb_leftsib &&
 		(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLDFSBNO) ||
 		 XFS_FSB_SANITY_CHECK(mp,
-		 	be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
+			be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
 		block->bb_u.l.bb_rightsib &&
 		(block->bb_u.l.bb_rightsib == cpu_to_be64(NULLDFSBNO) ||
 		 XFS_FSB_SANITY_CHECK(mp,
-		 	be64_to_cpu(block->bb_u.l.bb_rightsib)));
+			be64_to_cpu(block->bb_u.l.bb_rightsib)));
+
 	if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
 			XFS_ERRTAG_BTREE_CHECK_LBLOCK,
 			XFS_RANDOM_BTREE_CHECK_LBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
-		XFS_ERROR_REPORT("xfs_btree_check_lblock", XFS_ERRLEVEL_LOW,
-				 mp);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 	return 0;
@@ -90,16 +104,26 @@ xfs_btree_check_sblock(
 	int			level,	/* level of the btree block */
 	struct xfs_buf		*bp)	/* buffer containing block */
 {
+	struct xfs_mount	*mp;	/* file system mount point */
 	struct xfs_buf		*agbp;	/* buffer for ag. freespace struct */
 	struct xfs_agf		*agf;	/* ag. freespace structure */
 	xfs_agblock_t		agflen;	/* native ag. freespace length */
-	int			sblock_ok; /* block passes checks */
+	int			sblock_ok = 1; /* block passes checks */
 
+	mp = cur->bc_mp;
 	agbp = cur->bc_private.a.agbp;
 	agf = XFS_BUF_TO_AGF(agbp);
 	agflen = be32_to_cpu(agf->agf_length);
-	sblock_ok =
-		be32_to_cpu(block->bb_magic) == xfs_magics[cur->bc_btnum] &&
+
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		sblock_ok = sblock_ok &&
+			uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid) &&
+			block->bb_u.s.bb_blkno == cpu_to_be64(
+				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+	}
+
+	sblock_ok = sblock_ok &&
+		be32_to_cpu(block->bb_magic) == xfs_btree_magic(cur) &&
 		be16_to_cpu(block->bb_level) == level &&
 		be16_to_cpu(block->bb_numrecs) <=
 			cur->bc_ops->get_maxrecs(cur, level) &&
@@ -109,13 +133,13 @@ xfs_btree_check_sblock(
 		(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
 		 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
 		block->bb_u.s.bb_rightsib;
-	if (unlikely(XFS_TEST_ERROR(!sblock_ok, cur->bc_mp,
+
+	if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
 			XFS_ERRTAG_BTREE_CHECK_SBLOCK,
 			XFS_RANDOM_BTREE_CHECK_SBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
-		XFS_CORRUPTION_ERROR("xfs_btree_check_sblock",
-			XFS_ERRLEVEL_LOW, cur->bc_mp, block);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 	return 0;
@@ -194,6 +218,72 @@ xfs_btree_check_ptr(
 #endif
 
 /*
+ * Calculate CRC on the whole btree block and stuff it into the
+ * long-form btree header.
+ *
+ * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
+ * it into the buffer so recovery knows what the last modifcation was that made
+ * it to disk.
+ */
+void
+xfs_btree_lblock_calc_crc(
+	struct xfs_buf		*bp)
+{
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+
+	if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
+		return;
+	if (bip)
+		block->bb_u.l.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+			 XFS_BTREE_LBLOCK_CRC_OFF);
+}
+
+bool
+xfs_btree_lblock_verify_crc(
+	struct xfs_buf		*bp)
+{
+	if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
+		return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+					XFS_BTREE_LBLOCK_CRC_OFF);
+	return true;
+}
+
+/*
+ * Calculate CRC on the whole btree block and stuff it into the
+ * short-form btree header.
+ *
+ * Prior to calculting the CRC, pull the LSN out of the buffer log item and put
+ * it into the buffer so recovery knows what the last modifcation was that made
+ * it to disk.
+ */
+void
+xfs_btree_sblock_calc_crc(
+	struct xfs_buf		*bp)
+{
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	struct xfs_buf_log_item	*bip = bp->b_fspriv;
+
+	if (!xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
+		return;
+	if (bip)
+		block->bb_u.s.bb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+	xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+			 XFS_BTREE_SBLOCK_CRC_OFF);
+}
+
+bool
+xfs_btree_sblock_verify_crc(
+	struct xfs_buf		*bp)
+{
+	if (xfs_sb_version_hascrc(&bp->b_target->bt_mount->m_sb))
+		return xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+					XFS_BTREE_SBLOCK_CRC_OFF);
+	return true;
+}
+
+/*
  * Delete the btree cursor.
  */
 void
@@ -277,10 +367,8 @@ xfs_btree_dup_cursor(
 				*ncur = NULL;
 				return error;
 			}
-			new->bc_bufs[i] = bp;
-			ASSERT(!xfs_buf_geterror(bp));
-		} else
-			new->bc_bufs[i] = NULL;
+		}
+		new->bc_bufs[i] = bp;
 	}
 	*ncur = new;
 	return 0;
@@ -321,9 +409,14 @@ xfs_btree_dup_cursor(
  */
 static inline size_t xfs_btree_block_len(struct xfs_btree_cur *cur)
 {
-	return (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
-		XFS_BTREE_LBLOCK_LEN :
-		XFS_BTREE_SBLOCK_LEN;
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+		if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
+			return XFS_BTREE_LBLOCK_CRC_LEN;
+		return XFS_BTREE_LBLOCK_LEN;
+	}
+	if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS)
+		return XFS_BTREE_SBLOCK_CRC_LEN;
+	return XFS_BTREE_SBLOCK_LEN;
 }
 
 /*
@@ -863,43 +956,85 @@ xfs_btree_set_sibling(
 }
 
 void
+xfs_btree_init_block_int(
+	struct xfs_mount	*mp,
+	struct xfs_btree_block	*buf,
+	xfs_daddr_t		blkno,
+	__u32			magic,
+	__u16			level,
+	__u16			numrecs,
+	__u64			owner,
+	unsigned int		flags)
+{
+	buf->bb_magic = cpu_to_be32(magic);
+	buf->bb_level = cpu_to_be16(level);
+	buf->bb_numrecs = cpu_to_be16(numrecs);
+
+	if (flags & XFS_BTREE_LONG_PTRS) {
+		buf->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
+		buf->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
+		if (flags & XFS_BTREE_CRC_BLOCKS) {
+			buf->bb_u.l.bb_blkno = cpu_to_be64(blkno);
+			buf->bb_u.l.bb_owner = cpu_to_be64(owner);
+			uuid_copy(&buf->bb_u.l.bb_uuid, &mp->m_sb.sb_uuid);
+			buf->bb_u.l.bb_pad = 0;
+		}
+	} else {
+		/* owner is a 32 bit value on short blocks */
+		__u32 __owner = (__u32)owner;
+
+		buf->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
+		buf->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
+		if (flags & XFS_BTREE_CRC_BLOCKS) {
+			buf->bb_u.s.bb_blkno = cpu_to_be64(blkno);
+			buf->bb_u.s.bb_owner = cpu_to_be32(__owner);
+			uuid_copy(&buf->bb_u.s.bb_uuid, &mp->m_sb.sb_uuid);
+		}
+	}
+}
+
+void
 xfs_btree_init_block(
 	struct xfs_mount *mp,
 	struct xfs_buf	*bp,
 	__u32		magic,
 	__u16		level,
 	__u16		numrecs,
+	__u64		owner,
 	unsigned int	flags)
 {
-	struct xfs_btree_block	*new = XFS_BUF_TO_BLOCK(bp);
-
-	new->bb_magic = cpu_to_be32(magic);
-	new->bb_level = cpu_to_be16(level);
-	new->bb_numrecs = cpu_to_be16(numrecs);
-
-	if (flags & XFS_BTREE_LONG_PTRS) {
-		new->bb_u.l.bb_leftsib = cpu_to_be64(NULLDFSBNO);
-		new->bb_u.l.bb_rightsib = cpu_to_be64(NULLDFSBNO);
-	} else {
-		new->bb_u.s.bb_leftsib = cpu_to_be32(NULLAGBLOCK);
-		new->bb_u.s.bb_rightsib = cpu_to_be32(NULLAGBLOCK);
-	}
+	xfs_btree_init_block_int(mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
+				 magic, level, numrecs, owner, flags);
 }
 
 STATIC void
 xfs_btree_init_block_cur(
 	struct xfs_btree_cur	*cur,
+	struct xfs_buf		*bp,
 	int			level,
-	int			numrecs,
-	struct xfs_buf		*bp)
+	int			numrecs)
 {
-	xfs_btree_init_block(cur->bc_mp, bp, xfs_magics[cur->bc_btnum],
-			       level, numrecs, cur->bc_flags);
+	__u64 owner;
+
+	/*
+	 * we can pull the owner from the cursor right now as the different
+	 * owners align directly with the pointer size of the btree. This may
+	 * change in future, but is safe for current users of the generic btree
+	 * code.
+	 */
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		owner = cur->bc_private.b.ip->i_ino;
+	else
+		owner = cur->bc_private.a.agno;
+
+	xfs_btree_init_block_int(cur->bc_mp, XFS_BUF_TO_BLOCK(bp), bp->b_bn,
+				 xfs_btree_magic(cur), level, numrecs,
+				 owner, cur->bc_flags);
 }
 
 /*
  * Return true if ptr is the last record in the btree and
- * we need to track updateѕ to this record.  The decision
+ * we need to track updates to this record.  The decision
  * will be further refined in the update_lastrec method.
  */
 STATIC int
@@ -1147,6 +1282,7 @@ xfs_btree_log_keys(
 	XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
 
 	if (bp) {
+		xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLF_BTREE_BUF);
 		xfs_trans_log_buf(cur->bc_tp, bp,
 				  xfs_btree_key_offset(cur, first),
 				  xfs_btree_key_offset(cur, last + 1) - 1);
@@ -1171,6 +1307,7 @@ xfs_btree_log_recs(
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
 	XFS_BTREE_TRACE_ARGBII(cur, bp, first, last);
 
+	xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLF_BTREE_BUF);
 	xfs_trans_log_buf(cur->bc_tp, bp,
 			  xfs_btree_rec_offset(cur, first),
 			  xfs_btree_rec_offset(cur, last + 1) - 1);
@@ -1195,6 +1332,7 @@ xfs_btree_log_ptrs(
 		struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
 		int			level = xfs_btree_get_level(block);
 
+		xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLF_BTREE_BUF);
 		xfs_trans_log_buf(cur->bc_tp, bp,
 				xfs_btree_ptr_offset(cur, first, level),
 				xfs_btree_ptr_offset(cur, last + 1, level) - 1);
@@ -1223,7 +1361,12 @@ xfs_btree_log_block(
 		offsetof(struct xfs_btree_block, bb_numrecs),
 		offsetof(struct xfs_btree_block, bb_u.s.bb_leftsib),
 		offsetof(struct xfs_btree_block, bb_u.s.bb_rightsib),
-		XFS_BTREE_SBLOCK_LEN
+		offsetof(struct xfs_btree_block, bb_u.s.bb_blkno),
+		offsetof(struct xfs_btree_block, bb_u.s.bb_lsn),
+		offsetof(struct xfs_btree_block, bb_u.s.bb_uuid),
+		offsetof(struct xfs_btree_block, bb_u.s.bb_owner),
+		offsetof(struct xfs_btree_block, bb_u.s.bb_crc),
+		XFS_BTREE_SBLOCK_CRC_LEN
 	};
 	static const short	loffsets[] = {	/* table of offsets (long) */
 		offsetof(struct xfs_btree_block, bb_magic),
@@ -1231,17 +1374,40 @@ xfs_btree_log_block(
 		offsetof(struct xfs_btree_block, bb_numrecs),
 		offsetof(struct xfs_btree_block, bb_u.l.bb_leftsib),
 		offsetof(struct xfs_btree_block, bb_u.l.bb_rightsib),
-		XFS_BTREE_LBLOCK_LEN
+		offsetof(struct xfs_btree_block, bb_u.l.bb_blkno),
+		offsetof(struct xfs_btree_block, bb_u.l.bb_lsn),
+		offsetof(struct xfs_btree_block, bb_u.l.bb_uuid),
+		offsetof(struct xfs_btree_block, bb_u.l.bb_owner),
+		offsetof(struct xfs_btree_block, bb_u.l.bb_crc),
+		offsetof(struct xfs_btree_block, bb_u.l.bb_pad),
+		XFS_BTREE_LBLOCK_CRC_LEN
 	};
 
 	XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
 	XFS_BTREE_TRACE_ARGBI(cur, bp, fields);
 
 	if (bp) {
+		int nbits;
+
+		if (cur->bc_flags & XFS_BTREE_CRC_BLOCKS) {
+			/*
+			 * We don't log the CRC when updating a btree
+			 * block but instead recreate it during log
+			 * recovery.  As the log buffers have checksums
+			 * of their own this is safe and avoids logging a crc
+			 * update in a lot of places.
+			 */
+			if (fields == XFS_BB_ALL_BITS)
+				fields = XFS_BB_ALL_BITS_CRC;
+			nbits = XFS_BB_NUM_BITS_CRC;
+		} else {
+			nbits = XFS_BB_NUM_BITS;
+		}
 		xfs_btree_offsets(fields,
 				  (cur->bc_flags & XFS_BTREE_LONG_PTRS) ?
 					loffsets : soffsets,
-				  XFS_BB_NUM_BITS, &first, &last);
+				  nbits, &first, &last);
+		xfs_trans_buf_set_type(cur->bc_tp, bp, XFS_BLF_BTREE_BUF);
 		xfs_trans_log_buf(cur->bc_tp, bp, first, last);
 	} else {
 		xfs_trans_log_inode(cur->bc_tp, cur->bc_private.b.ip,
@@ -2204,7 +2370,7 @@ xfs_btree_split(
 		goto error0;
 
 	/* Fill in the btree header for the new right block. */
-	xfs_btree_init_block_cur(cur, xfs_btree_get_level(left), 0, rbp);
+	xfs_btree_init_block_cur(cur, rbp, xfs_btree_get_level(left), 0);
 
 	/*
 	 * Split the entries between the old and the new block evenly.
@@ -2513,7 +2679,7 @@ xfs_btree_new_root(
 		nptr = 2;
 	}
 	/* Fill in the new block's btree header and log it. */
-	xfs_btree_init_block_cur(cur, cur->bc_nlevels, 2, nbp);
+	xfs_btree_init_block_cur(cur, nbp, cur->bc_nlevels, 2);
 	xfs_btree_log_block(cur, nbp, XFS_BB_ALL_BITS);
 	ASSERT(!xfs_btree_ptr_is_null(cur, &lptr) &&
 			!xfs_btree_ptr_is_null(cur, &rptr));