From 99e4c750419e0bb24a1bbf094b1e6a5a4eedbc36 Mon Sep 17 00:00:00 2001 From: Tristan Ye Date: Fri, 18 Mar 2011 14:35:36 +0800 Subject: Ocfs2/move_extents: helper to validate and adjust moving goal. First best-effort attempt to validate and adjust the goal (physical address in block), while it can't guarantee later operation can succeed all the time since global_bitmap may change a bit over time. Signed-off-by: Tristan Ye --- fs/ocfs2/move_extents.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'fs/ocfs2') diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c index 68e00b47332b..e928a88f2db1 100644 --- a/fs/ocfs2/move_extents.c +++ b/fs/ocfs2/move_extents.c @@ -455,3 +455,64 @@ out: */ return ret; } + +/* + * XXX: helper to validate and adjust moving goal. + */ +static int ocfs2_validate_and_adjust_move_goal(struct inode *inode, + struct ocfs2_move_extents *range) +{ + int ret, goal_bit = 0; + + struct buffer_head *gd_bh = NULL; + struct ocfs2_group_desc *bg; + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + int c_to_b = 1 << (osb->s_clustersize_bits - + inode->i_sb->s_blocksize_bits); + + /* + * validate goal sits within global_bitmap, and return the victim + * group desc + */ + ret = ocfs2_find_victim_alloc_group(inode, range->me_goal, + GLOBAL_BITMAP_SYSTEM_INODE, + OCFS2_INVALID_SLOT, + &goal_bit, &gd_bh); + if (ret) + goto out; + + bg = (struct ocfs2_group_desc *)gd_bh->b_data; + + /* + * make goal become cluster aligned. + */ + if (range->me_goal % c_to_b) + range->me_goal = range->me_goal / c_to_b * c_to_b; + + /* + * moving goal is not allowd to start with a group desc blok(#0 blk) + * let's compromise to the latter cluster. + */ + if (range->me_goal == le64_to_cpu(bg->bg_blkno)) + range->me_goal += c_to_b; + + /* + * movement is not gonna cross two groups. + */ + if ((le16_to_cpu(bg->bg_bits) - goal_bit) * osb->s_clustersize < + range->me_len) { + ret = -EINVAL; + goto out; + } + /* + * more exact validations/adjustments will be performed later during + * moving operation for each extent range. + */ + mlog(0, "extents get ready to be moved to #%llu block\n", + range->me_goal); + +out: + brelse(gd_bh); + + return ret; +} -- cgit v1.2.3-59-g8ed1b