Commit cbc8adf8 authored by Dave Chinner's avatar Dave Chinner Committed by Ben Myers
Browse files

xfs: add CRC checking to dir2 free blocks 



This addition follows the same pattern as the dir2 block CRCs, but
with a few differences. The main difference is that the free block
header is different between the v2 and v3 formats, so an "in-core"
free block header has been added and _todisk/_from_disk functions
used to abstract the differences in structure format from the code.
This is similar to the on-disk superblock versus the in-core
superblock setup. The in-core strucutre is populated when the buffer
is read from disk, all the in memory checks and modifications are
done on the in-core version of the structure which is written back
to the buffer before the buffer is logged.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarBen Myers <bpm@sgi.com>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent f5f3d9b0

fs/xfs/xfs_dir2_format.h

+51 −4
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ 


#define	XFS_DIR3_BLOCK_MAGIC	0x58444233	/* XDB3: single block dirs */

#define	XFS_DIR3_DATA_MAGIC	0x58444433	/* XDD3: multiblock dirs */

#define	XFS_DIR3_FREE_MAGIC	0x58444633	/* XDF3: free index blocks */



/*

 * Byte offset in data block and shortform entry.
@@ -663,19 +664,65 @@ typedef struct xfs_dir2_free { 
						/* unused entries are -1 */

} xfs_dir2_free_t;



static inline int xfs_dir2_free_max_bests(struct xfs_mount *mp)

struct xfs_dir3_free_hdr {

	struct xfs_dir3_blk_hdr	hdr;

	__be32			firstdb;	/* db of first entry */

	__be32			nvalid;		/* count of valid entries */

	__be32			nused;		/* count of used entries */

};



struct xfs_dir3_free {

	struct xfs_dir3_free_hdr hdr;

	__be16			bests[];	/* best free counts */

						/* unused entries are -1 */

};



#define XFS_DIR3_FREE_CRC_OFF  offsetof(struct xfs_dir3_free, hdr.hdr.crc)



/*

 * In core version of the free block header, abstracted away from on-disk format

 * differences. Use this in the code, and convert to/from the disk version using

 * xfs_dir3_free_hdr_from_disk/xfs_dir3_free_hdr_to_disk.

 */

struct xfs_dir3_icfree_hdr {

	__uint32_t	magic;

	__uint32_t	firstdb;

	__uint32_t	nvalid;

	__uint32_t	nused;



};



void xfs_dir3_free_hdr_from_disk(struct xfs_dir3_icfree_hdr *to,

				 struct xfs_dir2_free *from);



static inline int

xfs_dir3_free_hdr_size(struct xfs_mount *mp)

{

	return (mp->m_dirblksize - sizeof(struct xfs_dir2_free_hdr)) /

	if (xfs_sb_version_hascrc(&mp->m_sb))

		return sizeof(struct xfs_dir3_free_hdr);

	return sizeof(struct xfs_dir2_free_hdr);

}



static inline int

xfs_dir3_free_max_bests(struct xfs_mount *mp)

{

	return (mp->m_dirblksize - xfs_dir3_free_hdr_size(mp)) /

		sizeof(xfs_dir2_data_off_t);

}



static inline __be16 *

xfs_dir3_free_bests_p(struct xfs_mount *mp, struct xfs_dir2_free *free)

{

	return (__be16 *)((char *)free + xfs_dir3_free_hdr_size(mp));

}



/*

 * Convert data space db to the corresponding free db.

 */

static inline xfs_dir2_db_t

xfs_dir2_db_to_fdb(struct xfs_mount *mp, xfs_dir2_db_t db)

{

	return XFS_DIR2_FREE_FIRSTDB(mp) + db / xfs_dir2_free_max_bests(mp);

	return XFS_DIR2_FREE_FIRSTDB(mp) + db / xfs_dir3_free_max_bests(mp);

}



/*
@@ -684,7 +731,7 @@ xfs_dir2_db_to_fdb(struct xfs_mount *mp, xfs_dir2_db_t db) 
static inline int

xfs_dir2_db_to_fdindex(struct xfs_mount *mp, xfs_dir2_db_t db)

{

	return db % xfs_dir2_free_max_bests(mp);

	return db % xfs_dir3_free_max_bests(mp);

}



/*

fs/xfs/xfs_dir2_leaf.c

+8 −7
Original line number Diff line number Diff line
@@ -1881,6 +1881,7 @@ xfs_dir2_node_to_leaf( 
	xfs_mount_t		*mp;		/* filesystem mount point */

	int			rval;		/* successful free trim? */

	xfs_trans_t		*tp;		/* transaction pointer */

	struct xfs_dir3_icfree_hdr freehdr;



	/*

	 * There's more than a leaf level in the btree, so there must
@@ -1938,15 +1939,15 @@ xfs_dir2_node_to_leaf( 
	if (error)

		return error;

	free = fbp->b_addr;

	ASSERT(free->hdr.magic == cpu_to_be32(XFS_DIR2_FREE_MAGIC));

	ASSERT(!free->hdr.firstdb);

	xfs_dir3_free_hdr_from_disk(&freehdr, free);



	ASSERT(!freehdr.firstdb);



	/*

	 * Now see if the leafn and free data will fit in a leaf1.

	 * If not, release the buffer and give up.

	 */

	if (xfs_dir2_leaf_size(&leaf->hdr, be32_to_cpu(free->hdr.nvalid)) >

			mp->m_dirblksize) {

	if (xfs_dir2_leaf_size(&leaf->hdr, freehdr.nvalid) > mp->m_dirblksize) {

		xfs_trans_brelse(tp, fbp);

		return 0;

	}
@@ -1967,12 +1968,12 @@ xfs_dir2_node_to_leaf( 
	 * Set up the leaf tail from the freespace block.

	 */

	ltp = xfs_dir2_leaf_tail_p(mp, leaf);

	ltp->bestcount = free->hdr.nvalid;

	ltp->bestcount = cpu_to_be32(freehdr.nvalid);

	/*

	 * Set up the leaf bests table.

	 */

	memcpy(xfs_dir2_leaf_bests_p(ltp), free->bests,

		be32_to_cpu(ltp->bestcount) * sizeof(xfs_dir2_data_off_t));

	memcpy(xfs_dir2_leaf_bests_p(ltp), xfs_dir3_free_bests_p(mp, free),

		freehdr.nvalid * sizeof(xfs_dir2_data_off_t));

	xfs_dir2_leaf_log_bests(tp, lbp, 0, be32_to_cpu(ltp->bestcount) - 1);

	xfs_dir2_leaf_log_tail(tp, lbp);

	xfs_dir2_leaf_check(dp, lbp);

fs/xfs/xfs_dir2_node.c

+323 −151

File changed.

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