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Commit 4ae1d69b authored by Joel Becker's avatar Joel Becker Committed by Mark Fasheh
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ocfs2: Wrap xattr block reads in a dedicated function 



We weren't consistently checking xattr blocks after we read them.
Most places checked the signature, but none checked xb_blkno or
xb_fs_signature.  Create a toplevel ocfs2_read_xattr_block() that does
the read and the validation.

Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
Signed-off-by: default avatarMark Fasheh <mfasheh@suse.com>
parent a22305cc

fs/ocfs2/xattr.c

+70 −24
Original line number Diff line number Diff line
@@ -314,6 +314,65 @@ static void ocfs2_xattr_bucket_copy_data(struct ocfs2_xattr_bucket *dest, 
	}

}



static int ocfs2_validate_xattr_block(struct super_block *sb,

				      struct buffer_head *bh)

{

	struct ocfs2_xattr_block *xb =

		(struct ocfs2_xattr_block *)bh->b_data;



	mlog(0, "Validating xattr block %llu\n",

	     (unsigned long long)bh->b_blocknr);



	if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {

		ocfs2_error(sb,

			    "Extended attribute block #%llu has bad "

			    "signature %.*s",

			    (unsigned long long)bh->b_blocknr, 7,

			    xb->xb_signature);

		return -EINVAL;

	}



	if (le64_to_cpu(xb->xb_blkno) != bh->b_blocknr) {

		ocfs2_error(sb,

			    "Extended attribute block #%llu has an "

			    "invalid xb_blkno of %llu",

			    (unsigned long long)bh->b_blocknr,

			    (unsigned long long)le64_to_cpu(xb->xb_blkno));

		return -EINVAL;

	}



	if (le32_to_cpu(xb->xb_fs_generation) != OCFS2_SB(sb)->fs_generation) {

		ocfs2_error(sb,

			    "Extended attribute block #%llu has an invalid "

			    "xb_fs_generation of #%u",

			    (unsigned long long)bh->b_blocknr,

			    le32_to_cpu(xb->xb_fs_generation));

		return -EINVAL;

	}



	return 0;

}



static int ocfs2_read_xattr_block(struct inode *inode, u64 xb_blkno,

				  struct buffer_head **bh)

{

	int rc;

	struct buffer_head *tmp = *bh;



	rc = ocfs2_read_block(inode, xb_blkno, &tmp);

	if (!rc) {

		rc = ocfs2_validate_xattr_block(inode->i_sb, tmp);

		if (rc)

			brelse(tmp);

	}



	/* If ocfs2_read_block() got us a new bh, pass it up. */

	if (!rc && !*bh)

		*bh = tmp;



	return rc;

}



static inline const char *ocfs2_xattr_prefix(int name_index)

{

	struct xattr_handler *handler = NULL;
@@ -739,18 +798,14 @@ static int ocfs2_xattr_block_list(struct inode *inode, 
	if (!di->i_xattr_loc)

		return ret;



	ret = ocfs2_read_block(inode, le64_to_cpu(di->i_xattr_loc), &blk_bh);

	ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),

				     &blk_bh);

	if (ret < 0) {

		mlog_errno(ret);

		return ret;

	}



	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {

		ret = -EIO;

		goto cleanup;

	}



	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {

		struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;

		ret = ocfs2_xattr_list_entries(inode, header,
@@ -760,7 +815,7 @@ static int ocfs2_xattr_block_list(struct inode *inode, 
		ret = ocfs2_xattr_tree_list_index_block(inode, xt,

						   buffer, buffer_size);

	}

cleanup:



	brelse(blk_bh);



	return ret;
@@ -1693,24 +1748,19 @@ static int ocfs2_xattr_free_block(struct inode *inode, 
	u64 blk, bg_blkno;

	u16 bit;



	ret = ocfs2_read_block(inode, block, &blk_bh);

	ret = ocfs2_read_xattr_block(inode, block, &blk_bh);

	if (ret < 0) {

		mlog_errno(ret);

		goto out;

	}



	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {

		ret = -EIO;

		goto out;

	}



	ret = ocfs2_xattr_block_remove(inode, blk_bh);

	if (ret < 0) {

		mlog_errno(ret);

		goto out;

	}



	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	blk = le64_to_cpu(xb->xb_blkno);

	bit = le16_to_cpu(xb->xb_suballoc_bit);

	bg_blkno = ocfs2_which_suballoc_group(blk, bit);
@@ -1950,19 +2000,15 @@ static int ocfs2_xattr_block_find(struct inode *inode, 
	if (!di->i_xattr_loc)

		return ret;



	ret = ocfs2_read_block(inode, le64_to_cpu(di->i_xattr_loc), &blk_bh);

	ret = ocfs2_read_xattr_block(inode, le64_to_cpu(di->i_xattr_loc),

				     &blk_bh);

	if (ret < 0) {

		mlog_errno(ret);

		return ret;

	}



	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

	if (!OCFS2_IS_VALID_XATTR_BLOCK(xb)) {

		ret = -EIO;

		goto cleanup;

	}



	xs->xattr_bh = blk_bh;

	xb = (struct ocfs2_xattr_block *)blk_bh->b_data;



	if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {

		xs->header = &xb->xb_attrs.xb_header;
@@ -2259,7 +2305,7 @@ static int ocfs2_calc_xattr_set_need(struct inode *inode, 
	/* calculate metadata allocation. */

	if (di->i_xattr_loc) {

		if (!xbs->xattr_bh) {

			ret = ocfs2_read_block(inode,

			ret = ocfs2_read_xattr_block(inode,

						     le64_to_cpu(di->i_xattr_loc),

						     &bh);

			if (ret) {