Btrfs: Add a clear_cache mount option
If something goes wrong with the free space cache we need a way to make sure
it's not loaded on mount and that it's cleared for everybody. When you pass the
clear_cache option it will make it so all block groups are setup to be cleared,
which keeps them from being loaded and then they will be truncated when the
transaction is committed. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 5c23eb8..5f56213 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -68,7 +68,7 @@
Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit,
- Opt_discard, Opt_space_cache, Opt_err,
+ Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_err,
};
static match_table_t tokens = {
@@ -93,6 +93,7 @@
{Opt_ratio, "metadata_ratio=%d"},
{Opt_discard, "discard"},
{Opt_space_cache, "space_cache"},
+ {Opt_clear_cache, "clear_cache"},
{Opt_err, NULL},
};
@@ -239,6 +240,9 @@
case Opt_space_cache:
printk(KERN_INFO "btrfs: enabling disk space caching\n");
btrfs_set_opt(info->mount_opt, SPACE_CACHE);
+ case Opt_clear_cache:
+ printk(KERN_INFO "btrfs: force clearing of disk cache\n");
+ btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
break;
case Opt_err:
printk(KERN_INFO "btrfs: unrecognized mount option "