Commit 68f64d47 authored by Joel Becker's avatar Joel Becker Committed by Mark Fasheh
Browse files

ocfs2: Wrap group descriptor reads in a dedicated function. 



We have a clean call for validating group descriptors, but every place
that wants the always does a read_block()+validate() call pair.  Create
a toplevel ocfs2_read_group_descriptor() that does the right
thing.  This allows us to leverage the single call point later for
fancier handling.  We also add validation of gd->bg_generation against
the superblock and gd->bg_blkno against the block we thought we read.

Signed-off-by: default avatarJoel Becker <joel.becker@oracle.com>
Signed-off-by: default avatarMark Fasheh <mfasheh@suse.com>
parent 57e3e797

fs/ocfs2/resize.c

+3 −9
Original line number Diff line number Diff line
@@ -330,20 +330,14 @@ int ocfs2_group_extend(struct inode * inode, int new_clusters) 
	lgd_blkno = ocfs2_which_cluster_group(main_bm_inode,

					      first_new_cluster - 1);



	ret = ocfs2_read_block(main_bm_inode, lgd_blkno, &group_bh);

	ret = ocfs2_read_group_descriptor(main_bm_inode, fe, lgd_blkno,

					  &group_bh);

	if (ret < 0) {

		mlog_errno(ret);

		goto out_unlock;

	}



	group = (struct ocfs2_group_desc *)group_bh->b_data;



	ret = ocfs2_check_group_descriptor(inode->i_sb, fe, group);

	if (ret) {

		mlog_errno(ret);

		goto out_unlock;

	}



	cl_bpc = le16_to_cpu(fe->id2.i_chain.cl_bpc);

	if (le16_to_cpu(group->bg_bits) / cl_bpc + new_clusters >

		le16_to_cpu(fe->id2.i_chain.cl_cpg)) {
@@ -400,7 +394,7 @@ static int ocfs2_check_new_group(struct inode *inode, 
		(struct ocfs2_group_desc *)group_bh->b_data;

	u16 cl_bpc = le16_to_cpu(di->id2.i_chain.cl_bpc);



	ret = ocfs2_validate_group_descriptor(inode->i_sb, di, gd, 1);

	ret = ocfs2_validate_group_descriptor(inode->i_sb, di, group_bh, 1);

	if (ret)

		goto out;

fs/ocfs2/suballoc.c

+65 −43
Original line number Diff line number Diff line
@@ -145,13 +145,13 @@ static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl) 
	return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);

}



/* somewhat more expensive than our other checks, so use sparingly. */

int ocfs2_validate_group_descriptor(struct super_block *sb,

				    struct ocfs2_dinode *di,

				    struct ocfs2_group_desc *gd,

				    struct buffer_head *bh,

				    int clean_error)

{

	unsigned int max_bits;

	struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;



#define do_error(fmt, ...)						\

	do{								\
@@ -162,16 +162,32 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	} while (0)



	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {

		do_error("Group Descriptor #%llu has bad signature %.*s",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno), 7,

		do_error("Group descriptor #%llu has bad signature %.*s",

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

			 gd->bg_signature);

		return -EINVAL;

	}



	if (le64_to_cpu(gd->bg_blkno) != bh->b_blocknr) {

		do_error("Group descriptor #%llu has an invalid bg_blkno "

			 "of %llu",

			 (unsigned long long)bh->b_blocknr,

			 (unsigned long long)le64_to_cpu(gd->bg_blkno));

		return -EINVAL;

	}



	if (le32_to_cpu(gd->bg_generation) != OCFS2_SB(sb)->fs_generation) {

		do_error("Group descriptor #%llu has an invalid "

			 "fs_generation of #%u",

			 (unsigned long long)bh->b_blocknr,

			 le32_to_cpu(gd->bg_generation));

		return -EINVAL;

	}



	if (di->i_blkno != gd->bg_parent_dinode) {

		do_error("Group descriptor #%llu has bad parent "

			 "pointer (%llu, expected %llu)",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno),

			 (unsigned long long)bh->b_blocknr,

			 (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),

			 (unsigned long long)le64_to_cpu(di->i_blkno));

		return -EINVAL;
@@ -180,7 +196,7 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);

	if (le16_to_cpu(gd->bg_bits) > max_bits) {

		do_error("Group descriptor #%llu has bit count of %u",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno),

			 (unsigned long long)bh->b_blocknr,

			 le16_to_cpu(gd->bg_bits));

		return -EINVAL;

	}
@@ -188,7 +204,7 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	if (le16_to_cpu(gd->bg_chain) >=

	    le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {

		do_error("Group descriptor #%llu has bad chain %u",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno),

			 (unsigned long long)bh->b_blocknr,

			 le16_to_cpu(gd->bg_chain));

		return -EINVAL;

	}
@@ -196,7 +212,7 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {

		do_error("Group descriptor #%llu has bit count %u but "

			 "claims that %u are free",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno),

			 (unsigned long long)bh->b_blocknr,

			 le16_to_cpu(gd->bg_bits),

			 le16_to_cpu(gd->bg_free_bits_count));

		return -EINVAL;
@@ -205,7 +221,7 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {

		do_error("Group descriptor #%llu has bit count %u but "

			 "max bitmap bits of %u",

			 (unsigned long long)le64_to_cpu(gd->bg_blkno),

			 (unsigned long long)bh->b_blocknr,

			 le16_to_cpu(gd->bg_bits),

			 8 * le16_to_cpu(gd->bg_size));

		return -EINVAL;
@@ -215,6 +231,30 @@ int ocfs2_validate_group_descriptor(struct super_block *sb, 
	return 0;

}



int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,

				u64 gd_blkno, struct buffer_head **bh)

{

	int rc;

	struct buffer_head *tmp = *bh;



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

	if (rc)

		goto out;



	rc = ocfs2_validate_group_descriptor(inode->i_sb, di, tmp, 0);

	if (rc) {

		brelse(tmp);

		goto out;

	}



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

	if (!*bh)

		*bh = tmp;



out:

	return rc;

}



static int ocfs2_block_group_fill(handle_t *handle,

				  struct inode *alloc_inode,

				  struct buffer_head *bg_bh,
@@ -1177,21 +1217,17 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac, 
	u16 found;

	struct buffer_head *group_bh = NULL;

	struct ocfs2_group_desc *gd;

	struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;

	struct inode *alloc_inode = ac->ac_inode;



	ret = ocfs2_read_block(alloc_inode, gd_blkno, &group_bh);

	ret = ocfs2_read_group_descriptor(alloc_inode, di, gd_blkno,

					  &group_bh);

	if (ret < 0) {

		mlog_errno(ret);

		return ret;

	}



	gd = (struct ocfs2_group_desc *) group_bh->b_data;

	if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {

		OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);

		ret = -EIO;

		goto out;

	}



	ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,

				  ac->ac_max_block, bit_off, &found);

	if (ret < 0) {
@@ -1248,7 +1284,7 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, 
	     bits_wanted, chain,

	     (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);



	status = ocfs2_read_block(alloc_inode,

	status = ocfs2_read_group_descriptor(alloc_inode, fe,

					     le64_to_cpu(cl->cl_recs[chain].c_blkno),

					     &group_bh);

	if (status < 0) {
@@ -1256,11 +1292,6 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, 
		goto bail;

	}

	bg = (struct ocfs2_group_desc *) group_bh->b_data;

	status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);

	if (status) {

		mlog_errno(status);

		goto bail;

	}



	status = -ENOSPC;

	/* for now, the chain search is a bit simplistic. We just use
@@ -1278,18 +1309,13 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac, 
		next_group = le64_to_cpu(bg->bg_next_group);

		prev_group_bh = group_bh;

		group_bh = NULL;

		status = ocfs2_read_block(alloc_inode,

		status = ocfs2_read_group_descriptor(alloc_inode, fe,

						     next_group, &group_bh);

		if (status < 0) {

			mlog_errno(status);

			goto bail;

		}

		bg = (struct ocfs2_group_desc *) group_bh->b_data;

		status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);

		if (status) {

			mlog_errno(status);

			goto bail;

		}

	}

	if (status < 0) {

		if (status != -ENOSPC)
@@ -1801,18 +1827,14 @@ int ocfs2_free_suballoc_bits(handle_t *handle, 
	     (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,

	     (unsigned long long)bg_blkno, start_bit);



	status = ocfs2_read_block(alloc_inode, bg_blkno, &group_bh);

	status = ocfs2_read_group_descriptor(alloc_inode, fe, bg_blkno,

					     &group_bh);

	if (status < 0) {

		mlog_errno(status);

		goto bail;

	}



	group = (struct ocfs2_group_desc *) group_bh->b_data;

	status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);

	if (status) {

		mlog_errno(status);

		goto bail;

	}



	BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));



	status = ocfs2_block_group_clear_bits(handle, alloc_inode,

fs/ocfs2/suballoc.h

+10 −9
Original line number Diff line number Diff line
@@ -164,23 +164,24 @@ void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac); 
 * and return that block offset. */

u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster);



/* somewhat more expensive than our other checks, so use sparingly. */

/*

 * By default, ocfs2_validate_group_descriptor() calls ocfs2_error() when it

 * finds a problem.  A caller that wants to check a group descriptor

 * without going readonly passes a nonzero clean_error.  This is only

 * resize, really.

 * resize, really.  Everyone else should be using

 * ocfs2_read_group_descriptor().

 */

int ocfs2_validate_group_descriptor(struct super_block *sb,

				    struct ocfs2_dinode *di,

				    struct ocfs2_group_desc *gd,

				    struct buffer_head *bh,

				    int clean_error);

static inline int ocfs2_check_group_descriptor(struct super_block *sb,

					       struct ocfs2_dinode *di,

					       struct ocfs2_group_desc *gd)

{

	return ocfs2_validate_group_descriptor(sb, di, gd, 0);

}

/*

 * Read a group descriptor block into *bh.  If *bh is NULL, a bh will be

 * allocated.  This is a cached read.  The descriptor will be validated with

 * ocfs2_validate_group_descriptor().

 */

int ocfs2_read_group_descriptor(struct inode *inode, struct ocfs2_dinode *di,

				u64 gd_blkno, struct buffer_head **bh);



int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_extent_tree *et,

			  u32 clusters_to_add, u32 extents_to_split,

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