Btrfs: add a log of past tree roots
This takes some of the free space in the btrfs super block
to record information about most of the roots in the last four
commits.
It also adds a -o recovery to use the root history log when
we're not able to read the tree of tree roots, the extent
tree root, the device tree root or the csum root.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index f7e9de7..57080df 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -164,7 +164,7 @@
Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
- Opt_inode_cache, Opt_no_space_cache, Opt_err,
+ Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err,
};
static match_table_t tokens = {
@@ -198,6 +198,7 @@
{Opt_defrag, "autodefrag"},
{Opt_inode_cache, "inode_cache"},
{Opt_no_space_cache, "no_space_cache"},
+ {Opt_recovery, "recovery"},
{Opt_err, NULL},
};
@@ -392,6 +393,10 @@
printk(KERN_INFO "btrfs: enabling auto defrag");
btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
break;
+ case Opt_recovery:
+ printk(KERN_INFO "btrfs: enabling auto recovery");
+ btrfs_set_opt(info->mount_opt, RECOVERY);
+ break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "
"'%s'\n", p);