bcachefs: Add BCH_SUBVOLUME_UNLINKED
Snapshot deletion needs to become a multi step process, where we unlink,
then tear down the page cache, then delete the subvolume - the deleting
flag is equivalent to an inode with i_nlink = 0.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 1608faa..56727001 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -353,6 +353,7 @@ enum bch_time_stats {
#include "quota_types.h"
#include "rebalance_types.h"
#include "replicas_types.h"
+#include "subvolume_types.h"
#include "super_types.h"
/* Number of nodes btree coalesce will try to coalesce at once */
@@ -657,6 +658,9 @@ struct bch_fs {
struct bch_snapshot_table __rcu *snapshot_table;
struct mutex snapshot_table_lock;
struct work_struct snapshot_delete_work;
+ struct work_struct snapshot_wait_for_pagecache_and_delete_work;
+ struct snapshot_id_list snapshots_unlinked;
+ struct mutex snapshots_unlinked_lock;
/* BTREE CACHE */
struct bio_set btree_bio;
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 481bf64..8e1423b 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -974,6 +974,7 @@ LE32_BITMASK(BCH_SUBVOLUME_RO, struct bch_subvolume, flags, 0, 1)
* can delete it (or whether it should just be rm -rf'd)
*/
LE32_BITMASK(BCH_SUBVOLUME_SNAP, struct bch_subvolume, flags, 1, 2)
+LE32_BITMASK(BCH_SUBVOLUME_UNLINKED, struct bch_subvolume, flags, 2, 3)
/* Snapshots */
diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
index c49de74..5f3429e99 100644
--- a/fs/bcachefs/fs-common.c
+++ b/fs/bcachefs/fs-common.c
@@ -239,7 +239,7 @@ int bch2_unlink_trans(struct btree_trans *trans,
struct bch_inode_unpacked *dir_u,
struct bch_inode_unpacked *inode_u,
const struct qstr *name,
- int deleting_snapshot)
+ bool deleting_snapshot)
{
struct bch_fs *c = trans->c;
struct btree_iter dir_iter = { NULL };
@@ -267,35 +267,19 @@ int bch2_unlink_trans(struct btree_trans *trans,
if (ret)
goto err;
- if (deleting_snapshot <= 0 && S_ISDIR(inode_u->bi_mode)) {
+ if (!deleting_snapshot && S_ISDIR(inode_u->bi_mode)) {
ret = bch2_empty_dir_trans(trans, inum);
if (ret)
goto err;
}
- if (deleting_snapshot < 0 &&
- inode_u->bi_subvol) {
- struct bch_subvolume s;
-
- ret = bch2_subvolume_get(trans, inode_u->bi_subvol, true,
- BTREE_ITER_CACHED|
- BTREE_ITER_WITH_UPDATES,
- &s);
- if (ret)
- goto err;
-
- if (BCH_SUBVOLUME_SNAP(&s))
- deleting_snapshot = 1;
+ if (deleting_snapshot && !inode_u->bi_subvol) {
+ ret = -ENOENT;
+ goto err;
}
- if (deleting_snapshot == 1) {
- if (!inode_u->bi_subvol) {
- ret = -ENOENT;
- goto err;
- }
-
- ret = bch2_subvolume_delete(trans, inode_u->bi_subvol,
- deleting_snapshot);
+ if (deleting_snapshot || inode_u->bi_subvol) {
+ ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol);
if (ret)
goto err;
diff --git a/fs/bcachefs/fs-common.h b/fs/bcachefs/fs-common.h
index 9bb0a96..dde2378 100644
--- a/fs/bcachefs/fs-common.h
+++ b/fs/bcachefs/fs-common.h
@@ -26,7 +26,7 @@ int bch2_link_trans(struct btree_trans *,
int bch2_unlink_trans(struct btree_trans *, subvol_inum,
struct bch_inode_unpacked *,
struct bch_inode_unpacked *,
- const struct qstr *, int);
+ const struct qstr *, bool);
int bch2_rename_trans(struct btree_trans *,
subvol_inum, struct bch_inode_unpacked *,
diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
index a12b591..de94895 100644
--- a/fs/bcachefs/fs-ioctl.c
+++ b/fs/bcachefs/fs-ioctl.c
@@ -441,7 +441,7 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
dir = path.dentry->d_parent->d_inode;
- ret = __bch2_unlink(dir, path.dentry, 1);
+ ret = __bch2_unlink(dir, path.dentry, true);
if (!ret) {
fsnotify_rmdir(dir, path.dentry);
d_delete(path.dentry);
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 334cd33..c325e5c 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -490,7 +490,7 @@ static int bch2_link(struct dentry *old_dentry, struct inode *vdir,
}
int __bch2_unlink(struct inode *vdir, struct dentry *dentry,
- int deleting_snapshot)
+ bool deleting_snapshot)
{
struct bch_fs *c = vdir->i_sb->s_fs_info;
struct bch_inode_info *dir = to_bch_ei(vdir);
@@ -527,7 +527,7 @@ int __bch2_unlink(struct inode *vdir, struct dentry *dentry,
static int bch2_unlink(struct inode *vdir, struct dentry *dentry)
{
- return __bch2_unlink(vdir, dentry, -1);
+ return __bch2_unlink(vdir, dentry, false);
}
static int bch2_symlink(struct mnt_idmap *idmap,
@@ -1292,6 +1292,12 @@ static int bch2_vfs_write_inode(struct inode *vinode,
return ret;
}
+static int bch2_drop_inode(struct inode *vinode)
+{
+
+ return generic_drop_inode(vinode);
+}
+
static void bch2_evict_inode(struct inode *vinode)
{
struct bch_fs *c = vinode->i_sb->s_fs_info;
@@ -1496,6 +1502,7 @@ static const struct super_operations bch_super_operations = {
.alloc_inode = bch2_alloc_inode,
.destroy_inode = bch2_destroy_inode,
.write_inode = bch2_vfs_write_inode,
+ .drop_inode = bch2_drop_inode,
.evict_inode = bch2_evict_inode,
.sync_fs = bch2_sync_fs,
.statfs = bch2_statfs,
diff --git a/fs/bcachefs/fs.h b/fs/bcachefs/fs.h
index 40898c4..2616b15 100644
--- a/fs/bcachefs/fs.h
+++ b/fs/bcachefs/fs.h
@@ -183,7 +183,7 @@ int __must_check bch2_write_inode(struct bch_fs *, struct bch_inode_info *,
int bch2_setattr_nonsize(struct mnt_idmap *,
struct bch_inode_info *,
struct iattr *);
-int __bch2_unlink(struct inode *, struct dentry *, int);
+int __bch2_unlink(struct inode *, struct dentry *, bool);
void bch2_vfs_exit(void);
int bch2_vfs_init(void);
diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index a61d380a..6b3eecd 100644
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -256,7 +256,7 @@ static int fsck_inode_rm(struct btree_trans *trans, u64 inum, u32 snapshot)
/* Subvolume root? */
if (inode_u.bi_subvol) {
- ret = bch2_subvolume_delete(trans, inode_u.bi_subvol, -1);
+ ret = bch2_subvolume_delete(trans, inode_u.bi_subvol);
if (ret)
goto err;
}
@@ -992,12 +992,28 @@ static int check_subvols(struct bch_fs *c)
struct btree_trans trans;
struct btree_iter iter;
struct bkey_s_c k;
+ struct bkey_s_c_subvolume subvol;
int ret;
bch2_trans_init(&trans, c, BTREE_ITER_MAX, 0);
for_each_btree_key(&trans, iter, BTREE_ID_subvolumes, POS_MIN,
0, k, ret) {
+ if (k.k->type != KEY_TYPE_subvolume)
+ continue;
+
+ subvol = bkey_s_c_to_subvolume(k);
+
+ if (BCH_SUBVOLUME_UNLINKED(subvol.v)) {
+ ret = __bch2_trans_do(&trans, NULL, NULL,
+ BTREE_INSERT_LAZY_RW,
+ bch2_subvolume_delete(&trans, iter.pos.offset));
+ if (ret) {
+ bch_err(c, "error deleting subvolume %llu: %i",
+ iter.pos.offset, ret);
+ break;
+ }
+ }
}
bch2_trans_iter_exit(&trans, &iter);
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 7fccf84..3ae321a 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -709,11 +709,7 @@ int bch2_inode_rm(struct bch_fs *c, subvol_inum inum, bool cached)
bch2_inode_unpack(bkey_s_c_to_inode(k), &inode_u);
/* Subvolume root? */
- if (inode_u.bi_subvol) {
- ret = bch2_subvolume_delete(&trans, inode_u.bi_subvol, -1);
- if (ret)
- goto err;
- }
+ BUG_ON(inode_u.bi_subvol);
bkey_inode_generation_init(&delete.k_i);
delete.k.p = iter.pos;
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
index 9bd8d61..58cda98 100644
--- a/fs/bcachefs/subvolume.c
+++ b/fs/bcachefs/subvolume.c
@@ -4,6 +4,7 @@
#include "btree_key_cache.h"
#include "btree_update.h"
#include "error.h"
+#include "fs.h"
#include "subvolume.h"
/* Snapshot tree: */
@@ -541,13 +542,6 @@ static int bch2_snapshot_node_create(struct btree_trans *trans, u32 parent,
return ret;
}
-/* List of snapshot IDs that are being deleted: */
-struct snapshot_id_list {
- u32 nr;
- u32 size;
- u32 *d;
-};
-
static bool snapshot_list_has_id(struct snapshot_id_list *s, u32 id)
{
unsigned i;
@@ -819,9 +813,11 @@ int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvol,
return ret;
}
-/* XXX: mark snapshot id for deletion, walk btree and delete: */
-int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid,
- int deleting_snapshot)
+/*
+ * Delete subvolume, mark snapshot ID as deleted, queue up snapshot
+ * deletion/cleanup:
+ */
+int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
{
struct btree_iter iter;
struct bkey_s_c k;
@@ -849,12 +845,6 @@ int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid,
subvol = bkey_s_c_to_subvolume(k);
snapid = le32_to_cpu(subvol.v->snapshot);
- if (deleting_snapshot >= 0 &&
- deleting_snapshot != BCH_SUBVOLUME_SNAP(subvol.v)) {
- ret = -ENOENT;
- goto err;
- }
-
delete = bch2_trans_kmalloc(trans, sizeof(*delete));
ret = PTR_ERR_OR_ZERO(delete);
if (ret)
@@ -880,6 +870,163 @@ int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid,
return ret;
}
+static void bch2_evict_subvolume_inodes(struct bch_fs *c,
+ struct snapshot_id_list *s)
+{
+ struct super_block *sb = c->vfs_sb;
+ struct inode *inode;
+
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ if (!snapshot_list_has_id(s, to_bch_ei(inode)->ei_subvol) ||
+ (inode->i_state & I_FREEING))
+ continue;
+
+ d_mark_dontcache(inode);
+ d_prune_aliases(inode);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+again:
+ cond_resched();
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ if (!snapshot_list_has_id(s, to_bch_ei(inode)->ei_subvol) ||
+ (inode->i_state & I_FREEING))
+ continue;
+
+ if (!(inode->i_state & I_DONTCACHE)) {
+ d_mark_dontcache(inode);
+ d_prune_aliases(inode);
+ }
+
+ spin_lock(&inode->i_lock);
+ if (snapshot_list_has_id(s, to_bch_ei(inode)->ei_subvol) &&
+ !(inode->i_state & I_FREEING)) {
+ wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_NEW);
+ DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW);
+ prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&sb->s_inode_list_lock);
+ schedule();
+ finish_wait(wq, &wait.wq_entry);
+ goto again;
+ }
+
+ spin_unlock(&inode->i_lock);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+}
+
+void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
+{
+ struct bch_fs *c = container_of(work, struct bch_fs,
+ snapshot_wait_for_pagecache_and_delete_work);
+ struct snapshot_id_list s;
+ u32 *id;
+ int ret = 0;
+
+ while (!ret) {
+ mutex_lock(&c->snapshots_unlinked_lock);
+ s = c->snapshots_unlinked;
+ memset(&c->snapshots_unlinked, 0, sizeof(c->snapshots_unlinked));
+ mutex_unlock(&c->snapshots_unlinked_lock);
+
+ if (!s.nr)
+ break;
+
+ bch2_evict_subvolume_inodes(c, &s);
+
+ for (id = s.d; id < s.d + s.nr; id++) {
+ ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_NOFAIL,
+ bch2_subvolume_delete(&trans, *id));
+ if (ret) {
+ bch_err(c, "error %i deleting subvolume %u", ret, *id);
+ break;
+ }
+ }
+
+ kfree(s.d);
+ }
+
+ percpu_ref_put(&c->writes);
+}
+
+struct subvolume_unlink_hook {
+ struct btree_trans_commit_hook h;
+ u32 subvol;
+};
+
+int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
+ struct btree_trans_commit_hook *_h)
+{
+ struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
+ struct bch_fs *c = trans->c;
+ int ret = 0;
+
+ mutex_lock(&c->snapshots_unlinked_lock);
+ if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
+ ret = snapshot_id_add(&c->snapshots_unlinked, h->subvol);
+ mutex_unlock(&c->snapshots_unlinked_lock);
+
+ if (ret)
+ return ret;
+
+ if (unlikely(!percpu_ref_tryget(&c->writes)))
+ return -EROFS;
+
+ if (!queue_work(system_long_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
+ percpu_ref_put(&c->writes);
+ return 0;
+}
+
+int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_i_subvolume *n;
+ struct subvolume_unlink_hook *h;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
+ POS(0, subvolid),
+ BTREE_ITER_CACHED|
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_subvolume) {
+ bch2_fs_inconsistent(trans->c, "missing subvolume %u", subvolid);
+ ret = -EIO;
+ goto err;
+ }
+
+ n = bch2_trans_kmalloc(trans, sizeof(*n));
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ goto err;
+
+ bkey_reassemble(&n->k_i, k);
+ SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
+
+ ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
+ if (ret)
+ goto err;
+
+ h = bch2_trans_kmalloc(trans, sizeof(*h));
+ ret = PTR_ERR_OR_ZERO(h);
+ if (ret)
+ goto err;
+
+ h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook;
+ h->subvol = subvolid;
+ bch2_trans_commit_hook(trans, &h->h);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
u32 src_subvolid,
u32 *new_subvolid,
@@ -977,5 +1124,8 @@ int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
int bch2_fs_subvolumes_init(struct bch_fs *c)
{
INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work);
+ INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work,
+ bch2_subvolume_wait_for_pagecache_and_delete);
+ mutex_init(&c->snapshots_unlinked_lock);
return 0;
}
diff --git a/fs/bcachefs/subvolume.h b/fs/bcachefs/subvolume.h
index f98c8c0..45234c9 100644
--- a/fs/bcachefs/subvolume.h
+++ b/fs/bcachefs/subvolume.h
@@ -2,6 +2,8 @@
#ifndef _BCACHEFS_SUBVOLUME_H
#define _BCACHEFS_SUBVOLUME_H
+#include "subvolume_types.h"
+
void bch2_snapshot_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
const char *bch2_snapshot_invalid(const struct bch_fs *, struct bkey_s_c);
@@ -108,7 +110,8 @@ int bch2_subvolume_get(struct btree_trans *, unsigned,
bool, int, struct bch_subvolume *);
int bch2_subvolume_get_snapshot(struct btree_trans *, u32, u32 *);
-int bch2_subvolume_delete(struct btree_trans *, u32, int);
+int bch2_subvolume_delete(struct btree_trans *, u32);
+int bch2_subvolume_unlink(struct btree_trans *, u32);
int bch2_subvolume_create(struct btree_trans *, u64, u32,
u32 *, u32 *, bool);
diff --git a/fs/bcachefs/subvolume_types.h b/fs/bcachefs/subvolume_types.h
new file mode 100644
index 0000000..9410b95
--- /dev/null
+++ b/fs/bcachefs/subvolume_types.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_SUBVOLUME_TYPES_H
+#define _BCACHEFS_SUBVOLUME_TYPES_H
+
+struct snapshot_id_list {
+ u32 nr;
+ u32 size;
+ u32 *d;
+};
+
+#endif /* _BCACHEFS_SUBVOLUME_TYPES_H */
