GFS2: Ensure that the inode goal block settings are updated (d9ba7615) · Commits · 戴 / test

GFS2 has a goal block associated with each inode indicating the search start position for future block allocations (in fact there are two, but thats for backward compatibility with GFS1 as they are set to identical locations in GFS2). In some circumstances, depending on the ordering of updates to the inode it was possible for the goal block settings to not be updated on disk. This patch ensures that the goal block will always get updated, thus reducing the potential for searching the same (already allocated) blocks again when looking for free space during block allocation. Signed-off-by:

Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/rgrp.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -1444,10 +1444,12 @@ static struct gfs2_rgrpd rgblk_free(struct gfs2_sbd sdp, u64 bstart,
		u64 gfs2_alloc_block(struct gfs2_inode ip, unsigned int n)
		{
		struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
		struct buffer_head *dibh;
		struct gfs2_alloc *al = ip->i_alloc;
		struct gfs2_rgrpd *rgd = al->al_rgd;
		u32 goal, blk;
		u64 block;
		int error;

		if (rgrp_contains_block(rgd, ip->i_goal))
		goal = ip->i_goal - rgd->rd_data0;
		@@ -1460,7 +1462,13 @@ u64 gfs2_alloc_block(struct gfs2_inode ip, unsigned int n)
		rgd->rd_last_alloc = blk;
		block = rgd->rd_data0 + blk;
		ip->i_goal = block;

		error = gfs2_meta_inode_buffer(ip, &dibh);
		if (error == 0) {
		struct gfs2_dinode di = (struct gfs2_dinode )dibh->b_data;
		gfs2_trans_add_bh(ip->i_gl, dibh, 1);
		di->di_goal_meta = di->di_goal_data = cpu_to_be64(ip->i_goal);
		brelse(dibh);
		}
		gfs2_assert_withdraw(sdp, rgd->rd_free >= *n);
		rgd->rd_free -= *n;

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