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authorTristan Ye <tristan.ye@oracle.com>2011-03-18 14:35:35 +0800
committerTristan Ye <tristan.ye@oracle.com>2011-05-25 15:17:10 +0800
commit1c06b9126130aa4a917bba81c39579ed08a67b4e (patch)
tree553ebd98601d3edcae182002f72246a04094d9c6 /fs/ocfs2/move_extents.c
parent202ee5facb2c55f36a4324a4f56d8bdf3617a579 (diff)
Ocfs2/move_extents: find the victim alloc group, where the given #blk fits.
This function tries locate the right alloc group, where a given physical block resides, it returns the caller a buffer_head of victim group descriptor, and also the offset of block in this group, by passing the block number. Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Diffstat (limited to 'fs/ocfs2/move_extents.c')
-rw-r--r--fs/ocfs2/move_extents.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 78db10d4c7f..68e00b47332 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -351,3 +351,107 @@ out:
return ret;
}
+
+/*
+ * find the victim alloc group, where #blkno fits.
+ */
+static int ocfs2_find_victim_alloc_group(struct inode *inode,
+ u64 vict_blkno,
+ int type, int slot,
+ int *vict_bit,
+ struct buffer_head **ret_bh)
+{
+ int ret, i, blocks_per_unit = 1;
+ u64 blkno;
+ char namebuf[40];
+
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct buffer_head *ac_bh = NULL, *gd_bh = NULL;
+ struct ocfs2_chain_list *cl;
+ struct ocfs2_chain_rec *rec;
+ struct ocfs2_dinode *ac_dinode;
+ struct ocfs2_group_desc *bg;
+
+ ocfs2_sprintf_system_inode_name(namebuf, sizeof(namebuf), type, slot);
+ ret = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
+ strlen(namebuf), &blkno);
+ if (ret) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = ocfs2_read_blocks_sync(osb, blkno, 1, &ac_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ac_dinode = (struct ocfs2_dinode *)ac_bh->b_data;
+ cl = &(ac_dinode->id2.i_chain);
+ rec = &(cl->cl_recs[0]);
+
+ if (type == GLOBAL_BITMAP_SYSTEM_INODE)
+ blocks_per_unit <<= (osb->s_clustersize_bits -
+ inode->i_sb->s_blocksize_bits);
+ /*
+ * 'vict_blkno' was out of the valid range.
+ */
+ if ((vict_blkno < le64_to_cpu(rec->c_blkno)) ||
+ (vict_blkno >= (le32_to_cpu(ac_dinode->id1.bitmap1.i_total) *
+ blocks_per_unit))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i++) {
+
+ rec = &(cl->cl_recs[i]);
+ if (!rec)
+ continue;
+
+ bg = NULL;
+
+ do {
+ if (!bg)
+ blkno = le64_to_cpu(rec->c_blkno);
+ else
+ blkno = le64_to_cpu(bg->bg_next_group);
+
+ if (gd_bh) {
+ brelse(gd_bh);
+ gd_bh = NULL;
+ }
+
+ ret = ocfs2_read_blocks_sync(osb, blkno, 1, &gd_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ bg = (struct ocfs2_group_desc *)gd_bh->b_data;
+
+ if (vict_blkno < (le64_to_cpu(bg->bg_blkno) +
+ le16_to_cpu(bg->bg_bits))) {
+
+ *ret_bh = gd_bh;
+ *vict_bit = (vict_blkno - blkno) /
+ blocks_per_unit;
+ mlog(0, "find the victim group: #%llu, "
+ "total_bits: %u, vict_bit: %u\n",
+ blkno, le16_to_cpu(bg->bg_bits),
+ *vict_bit);
+ goto out;
+ }
+
+ } while (le64_to_cpu(bg->bg_next_group));
+ }
+
+ ret = -EINVAL;
+out:
+ brelse(ac_bh);
+
+ /*
+ * caller has to release the gd_bh properly.
+ */
+ return ret;
+}