This patch introduces a new mount option - qgroup_auto_cleanup.
The purpose of this mount option is to cause btrfs to automatically
delete qgroups on subvolume deletion. This only cleans up the
associated level-0 qgroup, and not qgroups that are above it.
Since this behaviour is API-breaking, as people may already have scripts
that do this cleanup on subvolume destruction, this feature, at least
for now, must be opt-in.
Signed-off-by: Sargun Dhillon <sar...@sargun.me>
---
fs/btrfs/ctree.h | 1 +
fs/btrfs/ioctl.c | 15 +++++++++++++++
fs/btrfs/super.c | 15 ++++++++++++++-
3 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 643c70d..0300f6f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1348,6 +1348,7 @@ static inline u32 BTRFS_MAX_XATTR_SIZE(const struct
btrfs_fs_info *info)
#define BTRFS_MOUNT_FRAGMENT_METADATA (1 << 25)
#define BTRFS_MOUNT_FREE_SPACE_TREE (1 << 26)
#define BTRFS_MOUNT_NOLOGREPLAY (1 << 27)
+#define BTRFS_MOUNT_QGROUP_AUTO_CLEANUP (1 << 28)
#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
#define BTRFS_DEFAULT_MAX_INLINE (2048)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fba409f..04e4022 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2543,6 +2543,21 @@ static noinline int btrfs_ioctl_snap_destroy(struct file
*file,
goto out_end_trans;
}
}
+ /*
+ * Attempt to automatically remove the automatically attached qgroup
+ * setup in btrfs_qgroup_inherit. As a matter of convention, the id
+ * is the same as the subvolume id.
+ *
+ * This can fail non-fatally for level 0 qgroups, therefore we do
+ * not abort the transaction if this fails, nor return an error.
+ */
+ if (btrfs_test_opt(fs_info, QGROUP_AUTO_CLEANUP)) {
+ ret = btrfs_remove_qgroup(trans, fs_info,
+ dest->root_key.objectid, 0);
+ if (ret && ret != -ENOENT)
+ btrfs_warn(fs_info,
+ "Failed to cleanup qgroup. err: %d", ret);
+ }
out_end_trans:
trans->block_rsv = NULL;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 4f1cdd5..557f53f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -321,7 +321,8 @@ enum {
Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
- Opt_nologreplay, Opt_norecovery,
+ Opt_nologreplay, Opt_norecovery, Opt_qgroup_auto_cleanup,
+ Opt_no_qgroup_auto_cleanup,
#ifdef CONFIG_BTRFS_DEBUG
Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
#endif
@@ -381,6 +382,8 @@ static const match_table_t tokens = {
{Opt_rescan_uuid_tree, "rescan_uuid_tree"},
{Opt_fatal_errors, "fatal_errors=%s"},
{Opt_commit_interval, "commit=%d"},
+ {Opt_qgroup_auto_cleanup, "qgroup_auto_cleanup"},
+ {Opt_no_qgroup_auto_cleanup, "no_qgroup_auto_cleanup"},
#ifdef CONFIG_BTRFS_DEBUG
{Opt_fragment_data, "fragment=data"},
{Opt_fragment_metadata, "fragment=metadata"},
@@ -808,6 +811,14 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char
*options,
info->commit_interval =
BTRFS_DEFAULT_COMMIT_INTERVAL;
}
break;
+ case Opt_qgroup_auto_cleanup:
+ btrfs_set_and_info(info, QGROUP_AUTO_CLEANUP,
+ "enabling qgroup auto cleanup");
+ break;
+ case Opt_no_qgroup_auto_cleanup:
+ btrfs_clear_and_info(info, QGROUP_AUTO_CLEANUP,
+ "disabling qgroup auto cleanup");
+ break;
#ifdef CONFIG_BTRFS_DEBUG
case Opt_fragment_all:
btrfs_info(info, "fragmenting all space");
@@ -1299,6 +1310,8 @@ static int btrfs_show_options(struct seq_file *seq,
struct dentry *dentry)
seq_puts(seq, ",fatal_errors=panic");
if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
seq_printf(seq, ",commit=%d", info->commit_interval);
+ if (btrfs_test_opt(info, QGROUP_AUTO_CLEANUP))
+ seq_puts(seq, ",qgroup_auto_cleanup");
#ifdef CONFIG_BTRFS_DEBUG
if (btrfs_test_opt(info, FRAGMENT_DATA))
seq_puts(seq, ",fragment=data");
--
2.9.3
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