After resizing the filesystem, the secondary super block must be moved
to a new location. This adds a helper function for this.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
fs/nilfs2/super.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 57 insertions(+), 0 deletions(-)
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 062cca0..eba5b53 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -347,6 +347,63 @@ int nilfs_cleanup_super(struct super_block *sb)
return ret;
}
+/**
+ * nilfs_move_2nd_super - relocate secondary super block
+ * @sb: super block instance
+ * @sb2off: new offset of the secondary super block (in bytes)
+ */
+static int nilfs_move_2nd_super(struct super_block *sb, loff_t sb2off)
+{
+ struct the_nilfs *nilfs = sb->s_fs_info;
+ struct buffer_head *nsbh;
+ struct nilfs_super_block *nsbp;
+ sector_t blocknr, newblocknr;
+ unsigned long offset;
+ int sb2i = -1; /* array index of the secondary superblock */
+ int ret = 0;
+
+ /* nilfs->ns_sem must be locked by the caller. */
+ if (nilfs->ns_sbh[1] &&
+ nilfs->ns_sbh[1]->b_blocknr > nilfs->ns_first_data_block) {
+ sb2i = 1;
+ blocknr = nilfs->ns_sbh[1]->b_blocknr;
+ } else if (nilfs->ns_sbh[0]->b_blocknr > nilfs->ns_first_data_block) {
+ sb2i = 0;
+ blocknr = nilfs->ns_sbh[0]->b_blocknr;
+ }
+ if (sb2i >= 0 && (u64)blocknr << nilfs->ns_blocksize_bits == sb2off)
+ goto out; /* super block location is unchanged */
+
+ /* Get new super block buffer */
+ newblocknr = sb2off >> nilfs->ns_blocksize_bits;
+ offset = sb2off & (nilfs->ns_blocksize - 1);
+ nsbh = sb_getblk(sb, newblocknr);
+ if (!nsbh) {
+ printk(KERN_WARNING
+ "NILFS warning: unable to move secondary superblock "
+ "to block %llu\n", (unsigned long long)newblocknr);
+ ret = -EIO;
+ goto out;
+ }
+ nsbp = (void *)nsbh->b_data + offset;
+ memset(nsbp, 0, nilfs->ns_blocksize);
+
+ if (sb2i >= 0) {
+ memcpy(nsbp, nilfs->ns_sbp[sb2i], nilfs->ns_sbsize);
+ brelse(nilfs->ns_sbh[sb2i]);
+ nilfs->ns_sbh[sb2i] = nsbh;
+ nilfs->ns_sbp[sb2i] = nsbp;
+ } else if (nilfs->ns_sbh[0]->b_blocknr < nilfs->ns_first_data_block) {
+ /* secondary super block will be restored to index 1 */
+ nilfs->ns_sbh[1] = nsbh;
+ nilfs->ns_sbp[1] = nsbp;
+ } else {
+ brelse(nsbh);
+ }
+out:
+ return ret;
+}
+
static void nilfs_put_super(struct super_block *sb)
{
struct the_nilfs *nilfs = sb->s_fs_info;
--
1.7.3.5
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