Commit 941e6d7d authored by Steven Whitehouse's avatar Steven Whitehouse
Browse files

[GFS2] Speed up gfs2_write_alloc_required, deprecate gfs2_extent_map 



This patch removes the call to gfs2_extent_map from gfs2_write_alloc_required,
instead we call gfs2_block_map directly. This results in fewer overall calls
to gfs2_block_map in the multi-block case.

Also, gfs2_extent_map is marked as deprecated so that people know that its
going away as soon as all the callers have been converted.

Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent a9edadbf

fs/gfs2/bmap.c

+19 −17
Original line number Diff line number Diff line
@@ -548,6 +548,9 @@ out_fail: 
	return error;

}



/*

 * Deprecated: do not use in new code

 */

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

{

	struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 };
@@ -1197,10 +1200,9 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 
			      unsigned int len, int *alloc_required)

{

	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

	u64 lblock, lblock_stop, dblock;

	u32 extlen;

	int new = 0;

	int error = 0;

	struct buffer_head bh;

	unsigned int shift;

	u64 lblock, lblock_stop, size;



	*alloc_required = 0;
@@ -1214,6 +1216,8 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 
		return 0;

	}



	*alloc_required = 1;

	shift = sdp->sd_sb.sb_bsize_shift;

	if (gfs2_is_dir(ip)) {

		unsigned int bsize = sdp->sd_jbsize;

		lblock = offset;
@@ -1221,27 +1225,25 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, 
		lblock_stop = offset + len + bsize - 1;

		do_div(lblock_stop, bsize);

	} else {

		unsigned int shift = sdp->sd_sb.sb_bsize_shift;

		u64 end_of_file = (ip->i_di.di_size + sdp->sd_sb.sb_bsize - 1) >> shift;

		lblock = offset >> shift;

		lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;

		if (lblock_stop > end_of_file) {

			*alloc_required = 1;

		if (lblock_stop > end_of_file)

			return 0;

	}

	}



	for (; lblock < lblock_stop; lblock += extlen) {

		error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen);

		if (error)

			return error;



		if (!dblock) {

			*alloc_required = 1;

	size = (lblock_stop - lblock) << shift;

	do {

		bh.b_state = 0;

		bh.b_size = size;

		gfs2_block_map(&ip->i_inode, lblock, &bh, 0);

		if (!buffer_mapped(&bh))

			return 0;

		}

	}

		size -= bh.b_size;

		lblock += (bh.b_size >> ip->i_inode.i_blkbits);

	} while(size > 0);



	*alloc_required = 0;

	return 0;

}

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