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authorTristan Ye <tristan.ye@oracle.com>2011-03-18 14:35:36 +0800
committerTristan Ye <tristan.ye@oracle.com>2011-05-25 15:17:10 +0800
commit99e4c750419e0bb24a1bbf094b1e6a5a4eedbc36 (patch)
tree2d9fdf13b965f6b786b1831182df02d9d5d694da
parent1c06b9126130aa4a917bba81c39579ed08a67b4e (diff)
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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 <tristan.ye@oracle.com>
-rw-r--r--fs/ocfs2/move_extents.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 68e00b4..e928a88 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;
+}