Commit 4cf1ed81 authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

[GFS2] Tidy up bmap & fix boundary bug 



This moves the locking for bmap into the bmap function itself
rather than using a wrapper function. It also fixes a bug where
the boundary flag was set on the wrong bh. Also the flags on
the mapped bh are reset earlier in the function to ensure that
they are 100% correct on the error path.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent ab923031

fs/gfs2/bmap.c

+54 −63
Original line number Diff line number Diff line
@@ -423,12 +423,29 @@ static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh, 
	return 0;

}



static inline void bmap_lock(struct inode *inode, int create)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	if (create)

		down_write(&ip->i_rw_mutex);

	else

		down_read(&ip->i_rw_mutex);

}



static inline void bmap_unlock(struct inode *inode, int create)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	if (create)

		up_write(&ip->i_rw_mutex);

	else

		up_read(&ip->i_rw_mutex);

}



/**

 * gfs2_block_pointers - Map a block from an inode to a disk block

 * gfs2_block_map - Map a block from an inode to a disk block

 * @inode: The inode

 * @lblock: The logical block number

 * @map_bh: The bh to be mapped

 * @mp: metapath to use

 * @bh_map: The bh to be mapped

 *

 * Find the block number on the current device which corresponds to an

 * inode's block. If the block had to be created, "new" will be set.
@@ -436,8 +453,8 @@ static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh, 
 * Returns: errno

 */



static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,

			       struct buffer_head *bh_map, struct metapath *mp)

int gfs2_block_map(struct inode *inode, u64 lblock, int create,

		   struct buffer_head *bh_map)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	struct gfs2_sbd *sdp = GFS2_SB(inode);
@@ -451,51 +468,55 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create, 
	u64 dblock = 0;

	int boundary;

	unsigned int maxlen = bh_map->b_size >> inode->i_blkbits;

	struct metapath mp;

	u64 size;



	BUG_ON(maxlen == 0);



	if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))

		return 0;



	bmap_lock(inode, create);

	clear_buffer_mapped(bh_map);

	clear_buffer_new(bh_map);

	clear_buffer_boundary(bh_map);

	bsize = gfs2_is_dir(ip) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;

	size = (lblock + 1) * bsize;



	height = calc_tree_height(ip, (lblock + 1) * bsize);

	if (size > ip->i_di.di_size) {

		height = calc_tree_height(ip, size);

		if (ip->i_di.di_height < height) {

			if (!create)

			return 0;

				goto out_ok;

	

			error = build_height(inode, height);

			if (error)

			return error;

				goto out_fail;

		}

	}



	find_metapath(ip, lblock, mp);

	find_metapath(ip, lblock, &mp);

	end_of_metadata = ip->i_di.di_height - 1;



	error = gfs2_meta_inode_buffer(ip, &bh);

	if (error)

		return error;

		goto out_fail;



	for (x = 0; x < end_of_metadata; x++) {

		lookup_block(ip, bh, x, mp, create, &new, &dblock);

		lookup_block(ip, bh, x, &mp, create, &new, &dblock);

		brelse(bh);

		if (!dblock)

			return 0;

			goto out_ok;



		error = gfs2_meta_indirect_buffer(ip, x+1, dblock, new, &bh);

		if (error)

			return error;

			goto out_fail;

	}



	boundary = lookup_block(ip, bh, end_of_metadata, mp, create, &new, &dblock);

	clear_buffer_mapped(bh_map);

	clear_buffer_new(bh_map);

	clear_buffer_boundary(bh_map);



	boundary = lookup_block(ip, bh, end_of_metadata, &mp, create, &new, &dblock);

	if (dblock) {

		map_bh(bh_map, inode->i_sb, dblock);

		if (boundary)

			set_buffer_boundary(bh);

			set_buffer_boundary(bh_map);

		if (new) {

			struct buffer_head *dibh;

			error = gfs2_meta_inode_buffer(ip, &dibh);
@@ -510,8 +531,8 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create, 
		while(--maxlen && !buffer_boundary(bh_map)) {

			u64 eblock;



			mp->mp_list[end_of_metadata]++;

			boundary = lookup_block(ip, bh, end_of_metadata, mp, 0, &new, &eblock);

			mp.mp_list[end_of_metadata]++;

			boundary = lookup_block(ip, bh, end_of_metadata, &mp, 0, &new, &eblock);

			if (eblock != ++dblock)

				break;

			bh_map->b_size += (1 << inode->i_blkbits);
@@ -521,43 +542,15 @@ static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create, 
	}

out_brelse:

	brelse(bh);

	return 0;

}





static inline void bmap_lock(struct inode *inode, int create)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	if (create)

		down_write(&ip->i_rw_mutex);

	else

		down_read(&ip->i_rw_mutex);

}



static inline void bmap_unlock(struct inode *inode, int create)

{

	struct gfs2_inode *ip = GFS2_I(inode);

	if (create)

		up_write(&ip->i_rw_mutex);

	else

		up_read(&ip->i_rw_mutex);

}



int gfs2_block_map(struct inode *inode, u64 lblock, int create,

		   struct buffer_head *bh)

{

	struct metapath mp;

	int ret;



	bmap_lock(inode, create);

	ret = gfs2_block_pointers(inode, lblock, create, bh, &mp);

out_ok:

	error = 0;

out_fail:

	bmap_unlock(inode, create);

	return ret;

	return error;

}



int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)

{

	struct metapath mp;

	struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };

	int ret;

	int create = *new;
@@ -567,9 +560,7 @@ int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsi 
	BUG_ON(!new);



	bh.b_size = 1 << (inode->i_blkbits + 5);

	bmap_lock(inode, create);

	ret = gfs2_block_pointers(inode, lblock, create, &bh, &mp);

	bmap_unlock(inode, create);

	ret = gfs2_block_map(inode, lblock, create, &bh);

	*extlen = bh.b_size >> inode->i_blkbits;

	*dblock = bh.b_blocknr;

	if (buffer_new(&bh))

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