Commit 48a71399 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Darrick J. Wong
Browse files

xfs: cleanup __xfs_dir3_data_check 



Use an offset as the main means for iteration, and only do pointer
arithmetics to find the data/unused entries.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 62479f57

fs/xfs/libxfs/xfs_dir2_data.c

+33 −26
Original line number Diff line number Diff line
@@ -23,6 +23,22 @@ static xfs_failaddr_t xfs_dir2_data_freefind_verify( 
		struct xfs_dir2_data_unused *dup,

		struct xfs_dir2_data_free **bf_ent);



/*

 * The number of leaf entries is limited by the size of the block and the amount

 * of space used by the data entries.  We don't know how much space is used by

 * the data entries yet, so just ensure that the count falls somewhere inside

 * the block right now.

 */

static inline unsigned int

xfs_dir2_data_max_leaf_entries(

	const struct xfs_dir_ops	*ops,

	struct xfs_da_geometry		*geo)

{

	return (geo->blksize - sizeof(struct xfs_dir2_block_tail) -

		ops->data_entry_offset) /

			sizeof(struct xfs_dir2_leaf_entry);

}



/*

 * Check the consistency of the data block.

 * The input can also be a block-format directory.
@@ -38,23 +54,20 @@ __xfs_dir3_data_check( 
	xfs_dir2_block_tail_t	*btp=NULL;	/* block tail */

	int			count;		/* count of entries found */

	xfs_dir2_data_hdr_t	*hdr;		/* data block header */

	xfs_dir2_data_entry_t	*dep;		/* data entry */

	xfs_dir2_data_free_t	*dfp;		/* bestfree entry */

	xfs_dir2_data_unused_t	*dup;		/* unused entry */

	char			*endp;		/* end of useful data */

	void			*endp;		/* end of useful data */

	int			freeseen;	/* mask of bestfrees seen */

	xfs_dahash_t		hash;		/* hash of current name */

	int			i;		/* leaf index */

	int			lastfree;	/* last entry was unused */

	xfs_dir2_leaf_entry_t	*lep=NULL;	/* block leaf entries */

	struct xfs_mount	*mp = bp->b_mount;

	char			*p;		/* current data position */

	int			stale;		/* count of stale leaves */

	struct xfs_name		name;

	unsigned int		offset;

	unsigned int		end;

	const struct xfs_dir_ops *ops;

	struct xfs_da_geometry	*geo;



	geo = mp->m_dir_geo;

	struct xfs_da_geometry	*geo = mp->m_dir_geo;



	/*

	 * We can be passed a null dp here from a verifier, so we need to go the
@@ -71,7 +84,7 @@ __xfs_dir3_data_check( 
		return __this_address;



	hdr = bp->b_addr;

	p = (char *)ops->data_entry_p(hdr);

	offset = ops->data_entry_offset;



	switch (hdr->magic) {

	case cpu_to_be32(XFS_DIR3_BLOCK_MAGIC):
@@ -79,15 +92,8 @@ __xfs_dir3_data_check( 
		btp = xfs_dir2_block_tail_p(geo, hdr);

		lep = xfs_dir2_block_leaf_p(btp);



		/*

		 * The number of leaf entries is limited by the size of the

		 * block and the amount of space used by the data entries.

		 * We don't know how much space is used by the data entries yet,

		 * so just ensure that the count falls somewhere inside the

		 * block right now.

		 */

		if (be32_to_cpu(btp->count) >=

		    ((char *)btp - p) / sizeof(struct xfs_dir2_leaf_entry))

		    xfs_dir2_data_max_leaf_entries(ops, geo))

			return __this_address;

		break;

	case cpu_to_be32(XFS_DIR3_DATA_MAGIC):
@@ -99,6 +105,7 @@ __xfs_dir3_data_check( 
	endp = xfs_dir3_data_endp(geo, hdr);

	if (!endp)

		return __this_address;

	end = endp - bp->b_addr;



	/*

	 * Account for zero bestfree entries.
@@ -128,8 +135,10 @@ __xfs_dir3_data_check( 
	/*

	 * Loop over the data/unused entries.

	 */

	while (p < endp) {

		dup = (xfs_dir2_data_unused_t *)p;

	while (offset < end) {

		struct xfs_dir2_data_unused	*dup = bp->b_addr + offset;

		struct xfs_dir2_data_entry	*dep = bp->b_addr + offset;



		/*

		 * If it's unused, look for the space in the bestfree table.

		 * If we find it, account for that, else make sure it
@@ -140,10 +149,10 @@ __xfs_dir3_data_check( 


			if (lastfree != 0)

				return __this_address;

			if (endp < p + be16_to_cpu(dup->length))

			if (offset + be16_to_cpu(dup->length) > end)

				return __this_address;

			if (be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) !=

			    (char *)dup - (char *)hdr)

			    offset)

				return __this_address;

			fa = xfs_dir2_data_freefind_verify(hdr, bf, dup, &dfp);

			if (fa)
@@ -158,7 +167,7 @@ __xfs_dir3_data_check( 
				    be16_to_cpu(bf[2].length))

					return __this_address;

			}

			p += be16_to_cpu(dup->length);

			offset += be16_to_cpu(dup->length);

			lastfree = 1;

			continue;

		}
@@ -168,15 +177,13 @@ __xfs_dir3_data_check( 
		 * in the leaf section of the block.

		 * The linear search is crude but this is DEBUG code.

		 */

		dep = (xfs_dir2_data_entry_t *)p;

		if (dep->namelen == 0)

			return __this_address;

		if (xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)))

			return __this_address;

		if (endp < p + ops->data_entsize(dep->namelen))

		if (offset + ops->data_entsize(dep->namelen) > end)

			return __this_address;

		if (be16_to_cpu(*ops->data_entry_tag_p(dep)) !=

		    (char *)dep - (char *)hdr)

		if (be16_to_cpu(*ops->data_entry_tag_p(dep)) != offset)

			return __this_address;

		if (ops->data_get_ftype(dep) >= XFS_DIR3_FT_MAX)

			return __this_address;
@@ -198,7 +205,7 @@ __xfs_dir3_data_check( 
			if (i >= be32_to_cpu(btp->count))

				return __this_address;

		}

		p += ops->data_entsize(dep->namelen);

		offset += ops->data_entsize(dep->namelen);

	}

	/*

	 * Need to have seen all the entries and all the bestfree slots.

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