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-rw-r--r--fs/bcachefs/Makefile1
-rw-r--r--fs/bcachefs/bcachefs.h23
-rw-r--r--fs/bcachefs/bcachefs_format.h55
-rw-r--r--fs/bcachefs/bcachefs_ioctl.h15
-rw-r--r--fs/bcachefs/bkey_methods.c5
-rw-r--r--fs/bcachefs/btree_key_cache.c5
-rw-r--r--fs/bcachefs/btree_types.h15
-rw-r--r--fs/bcachefs/btree_update_leaf.c6
-rw-r--r--fs/bcachefs/buckets.c3
-rw-r--r--fs/bcachefs/dirent.c5
-rw-r--r--fs/bcachefs/fsck.c4
-rw-r--r--fs/bcachefs/inode.c15
-rw-r--r--fs/bcachefs/opts.c3
-rw-r--r--fs/bcachefs/recovery.c121
-rw-r--r--fs/bcachefs/subvolume.c981
-rw-r--r--fs/bcachefs/subvolume.h77
-rw-r--r--fs/bcachefs/super.c4
17 files changed, 1314 insertions, 24 deletions
diff --git a/fs/bcachefs/Makefile b/fs/bcachefs/Makefile
index af3b83f871df..a2769a85b029 100644
--- a/fs/bcachefs/Makefile
+++ b/fs/bcachefs/Makefile
@@ -50,6 +50,7 @@ bcachefs-y := \
replicas.o \
siphash.o \
six.o \
+ subvolume.o \
super.o \
super-io.o \
sysfs.o \
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 114ae77a8a02..1608faae0d0b 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -381,6 +381,8 @@ enum gc_phase {
GC_PHASE_BTREE_alloc,
GC_PHASE_BTREE_quotas,
GC_PHASE_BTREE_reflink,
+ GC_PHASE_BTREE_subvolumes,
+ GC_PHASE_BTREE_snapshots,
GC_PHASE_PENDING_DELETE,
};
@@ -564,6 +566,21 @@ struct btree_path_buf {
#define REPLICAS_DELTA_LIST_MAX (1U << 16)
+struct snapshot_t {
+ u32 parent;
+ u32 children[2];
+ u32 subvol; /* Nonzero only if a subvolume points to this node: */
+ u32 equiv;
+};
+
+typedef struct {
+ u32 subvol;
+ u64 inum;
+} subvol_inum;
+
+#define BCACHEFS_ROOT_SUBVOL_INUM \
+ ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO })
+
struct bch_fs {
struct closure cl;
@@ -635,6 +652,12 @@ struct bch_fs {
struct closure sb_write;
struct mutex sb_lock;
+ /* snapshot.c: */
+ GENRADIX(struct snapshot_t) snapshots;
+ struct bch_snapshot_table __rcu *snapshot_table;
+ struct mutex snapshot_table_lock;
+ struct work_struct snapshot_delete_work;
+
/* BTREE CACHE */
struct bio_set btree_bio;
struct workqueue_struct *io_complete_wq;
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 156198850b67..ae8f3a5bc787 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -346,7 +346,9 @@ static inline void bkey_init(struct bkey *k)
x(inline_data, 17) \
x(btree_ptr_v2, 18) \
x(indirect_inline_data, 19) \
- x(alloc_v2, 20)
+ x(alloc_v2, 20) \
+ x(subvolume, 21) \
+ x(snapshot, 22)
enum bch_bkey_type {
#define x(name, nr) KEY_TYPE_##name = nr,
@@ -690,6 +692,10 @@ struct bch_inode_generation {
__le32 pad;
} __attribute__((packed, aligned(8)));
+/*
+ * bi_subvol and bi_parent_subvol are only set for subvolume roots:
+ */
+
#define BCH_INODE_FIELDS() \
x(bi_atime, 96) \
x(bi_ctime, 96) \
@@ -713,7 +719,9 @@ struct bch_inode_generation {
x(bi_erasure_code, 16) \
x(bi_fields_set, 16) \
x(bi_dir, 64) \
- x(bi_dir_offset, 64)
+ x(bi_dir_offset, 64) \
+ x(bi_subvol, 32) \
+ x(bi_parent_subvol, 32)
/* subset of BCH_INODE_FIELDS */
#define BCH_INODE_OPTS() \
@@ -796,6 +804,9 @@ struct bch_dirent {
__u8 d_name[];
} __attribute__((packed, aligned(8)));
+#define DT_SUBVOL 16
+#define BCH_DT_MAX 17
+
#define BCH_NAME_MAX (U8_MAX * sizeof(u64) - \
sizeof(struct bkey) - \
offsetof(struct bch_dirent, d_name))
@@ -932,6 +943,42 @@ struct bch_inline_data {
u8 data[0];
};
+/* Subvolumes: */
+
+#define SUBVOL_POS_MIN POS(0, 1)
+#define SUBVOL_POS_MAX POS(0, S32_MAX)
+#define BCACHEFS_ROOT_SUBVOL 1
+
+struct bch_subvolume {
+ struct bch_val v;
+ __le32 flags;
+ __le32 snapshot;
+ __le64 inode;
+};
+
+LE32_BITMASK(BCH_SUBVOLUME_RO, struct bch_subvolume, flags, 0, 1)
+/*
+ * We need to know whether a subvolume is a snapshot so we can know whether we
+ * can delete it (or whether it should just be rm -rf'd)
+ */
+LE32_BITMASK(BCH_SUBVOLUME_SNAP, struct bch_subvolume, flags, 1, 2)
+
+/* Snapshots */
+
+struct bch_snapshot {
+ struct bch_val v;
+ __le32 flags;
+ __le32 parent;
+ __le32 children[2];
+ __le32 subvol;
+ __le32 pad;
+};
+
+LE32_BITMASK(BCH_SNAPSHOT_DELETED, struct bch_snapshot, flags, 0, 1)
+
+/* True if a subvolume points to this snapshot node: */
+LE32_BITMASK(BCH_SNAPSHOT_SUBVOL, struct bch_snapshot, flags, 1, 2)
+
/* Optional/variable size superblock sections: */
struct bch_sb_field {
@@ -1702,7 +1749,9 @@ LE32_BITMASK(JSET_NO_FLUSH, struct jset, flags, 5, 6);
x(alloc, 4) \
x(quotas, 5) \
x(stripes, 6) \
- x(reflink, 7)
+ x(reflink, 7) \
+ x(subvolumes, 8) \
+ x(snapshots, 9)
enum btree_id {
#define x(kwd, val) BTREE_ID_##kwd = val,
diff --git a/fs/bcachefs/bcachefs_ioctl.h b/fs/bcachefs/bcachefs_ioctl.h
index 1ef9907e07ad..66ab3aea9767 100644
--- a/fs/bcachefs/bcachefs_ioctl.h
+++ b/fs/bcachefs/bcachefs_ioctl.h
@@ -78,6 +78,9 @@ struct bch_ioctl_incremental {
#define BCH_IOCTL_DISK_RESIZE _IOW(0xbc, 14, struct bch_ioctl_disk_resize)
#define BCH_IOCTL_DISK_RESIZE_JOURNAL _IOW(0xbc,15, struct bch_ioctl_disk_resize_journal)
+#define BCH_IOCTL_SUBVOLUME_CREATE _IOW(0xbc, 16, struct bch_ioctl_subvolume)
+#define BCH_IOCTL_SUBVOLUME_DESTROY _IOW(0xbc, 17, struct bch_ioctl_subvolume)
+
/* ioctl below act on a particular file, not the filesystem as a whole: */
#define BCHFS_IOC_REINHERIT_ATTRS _IOR(0xbc, 64, const char __user *)
@@ -349,4 +352,16 @@ struct bch_ioctl_disk_resize_journal {
__u64 nbuckets;
};
+struct bch_ioctl_subvolume {
+ __u32 flags;
+ __u32 dirfd;
+ __u16 mode;
+ __u16 pad[3];
+ __u64 dst_ptr;
+ __u64 src_ptr;
+};
+
+#define BCH_SUBVOL_SNAPSHOT_CREATE (1U << 0)
+#define BCH_SUBVOL_SNAPSHOT_RO (1U << 1)
+
#endif /* _BCACHEFS_IOCTL_H */
diff --git a/fs/bcachefs/bkey_methods.c b/fs/bcachefs/bkey_methods.c
index 8efef485c6d8..42fdcc4487de 100644
--- a/fs/bcachefs/bkey_methods.c
+++ b/fs/bcachefs/bkey_methods.c
@@ -11,6 +11,7 @@
#include "inode.h"
#include "quota.h"
#include "reflink.h"
+#include "subvolume.h"
#include "xattr.h"
const char * const bch2_bkey_types[] = {
@@ -126,6 +127,10 @@ static unsigned bch2_key_types_allowed[] = {
[BKEY_TYPE_reflink] =
(1U << KEY_TYPE_reflink_v)|
(1U << KEY_TYPE_indirect_inline_data),
+ [BKEY_TYPE_subvolumes] =
+ (1U << KEY_TYPE_subvolume),
+ [BKEY_TYPE_snapshots] =
+ (1U << KEY_TYPE_snapshot),
[BKEY_TYPE_btree] =
(1U << KEY_TYPE_btree_ptr)|
(1U << KEY_TYPE_btree_ptr_v2),
diff --git a/fs/bcachefs/btree_key_cache.c b/fs/bcachefs/btree_key_cache.c
index 9bdc2c3f21bf..7be580555374 100644
--- a/fs/bcachefs/btree_key_cache.c
+++ b/fs/bcachefs/btree_key_cache.c
@@ -164,6 +164,11 @@ btree_key_cache_create(struct btree_key_cache *c,
was_new = false;
}
+ if (btree_id == BTREE_ID_subvolumes)
+ six_lock_pcpu_alloc(&ck->c.lock);
+ else
+ six_lock_pcpu_free(&ck->c.lock);
+
ck->c.level = 0;
ck->c.btree_id = btree_id;
ck->key.btree_id = btree_id;
diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index b7cded2095ff..9250ac69e8b1 100644
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -606,7 +606,8 @@ static inline bool btree_node_is_extents(struct btree *b)
#define BTREE_NODE_TYPE_HAS_MEM_TRIGGERS \
((1U << BKEY_TYPE_alloc)| \
- (1U << BKEY_TYPE_stripes))
+ (1U << BKEY_TYPE_stripes)| \
+ (1U << BKEY_TYPE_snapshots))
#define BTREE_NODE_TYPE_HAS_TRIGGERS \
(BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS| \
@@ -653,7 +654,8 @@ enum btree_update_flags {
#define BTREE_TRIGGER_WANTS_OLD_AND_NEW \
((1U << KEY_TYPE_stripe)| \
- (1U << KEY_TYPE_inode))
+ (1U << KEY_TYPE_inode)| \
+ (1U << KEY_TYPE_snapshot))
static inline bool btree_node_type_needs_gc(enum btree_node_type type)
{
@@ -670,11 +672,6 @@ struct btree_root {
s8 error;
};
-/*
- * Optional hook that will be called just prior to a btree node update, when
- * we're holding the write lock and we know what key is about to be overwritten:
- */
-
enum btree_insert_ret {
BTREE_INSERT_OK,
/* leaf node needs to be split */
@@ -695,8 +692,4 @@ enum btree_node_sibling {
btree_next_sib,
};
-typedef struct btree_nr_keys (*sort_fix_overlapping_fn)(struct bset *,
- struct btree *,
- struct btree_node_iter *);
-
#endif /* _BCACHEFS_BTREE_TYPES_H */
diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
index 8ab771334557..6e904f9195cc 100644
--- a/fs/bcachefs/btree_update_leaf.c
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -15,6 +15,7 @@
#include "journal.h"
#include "journal_reclaim.h"
#include "keylist.h"
+#include "subvolume.h"
#include "replicas.h"
#include "trace.h"
@@ -245,6 +246,11 @@ static inline void btree_insert_entry_checks(struct btree_trans *trans,
BUG_ON(i->cached != i->path->cached);
BUG_ON(i->level != i->path->level);
BUG_ON(i->btree_id != i->path->btree_id);
+ EBUG_ON(!i->level &&
+ !(i->flags & BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) &&
+ test_bit(JOURNAL_REPLAY_DONE, &trans->c->journal.flags) &&
+ i->k->k.p.snapshot &&
+ bch2_snapshot_internal_node(trans->c, i->k->k.p.snapshot));
}
static noinline int
diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index 6831c002961d..2d2bdfb7977d 100644
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -16,6 +16,7 @@
#include "movinggc.h"
#include "reflink.h"
#include "replicas.h"
+#include "subvolume.h"
#include "trace.h"
#include <linux/preempt.h>
@@ -1204,6 +1205,8 @@ static int bch2_mark_key_locked(struct bch_fs *c,
return bch2_mark_reservation(c, old, new, journal_seq, flags);
case KEY_TYPE_reflink_p:
return bch2_mark_reflink_p(c, old, new, journal_seq, flags);
+ case KEY_TYPE_snapshot:
+ return bch2_mark_snapshot(c, old, new, journal_seq, flags);
default:
return 0;
}
diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
index 1d510f7728b6..53c7687a9ca8 100644
--- a/fs/bcachefs/dirent.c
+++ b/fs/bcachefs/dirent.c
@@ -99,7 +99,8 @@ const char *bch2_dirent_invalid(const struct bch_fs *c, struct bkey_s_c k)
if (memchr(d.v->d_name, '/', len))
return "invalid name";
- if (le64_to_cpu(d.v->d_inum) == d.k->p.inode)
+ if (d.v->d_type != DT_SUBVOL &&
+ le64_to_cpu(d.v->d_inum) == d.k->p.inode)
return "dirent points to own directory";
return NULL;
@@ -113,7 +114,7 @@ void bch2_dirent_to_text(struct printbuf *out, struct bch_fs *c,
bch_scnmemcpy(out, d.v->d_name,
bch2_dirent_name_bytes(d));
pr_buf(out, " -> %llu type %s", d.v->d_inum,
- d.v->d_type < DT_MAX
+ d.v->d_type < BCH_DT_MAX
? bch2_d_types[d.v->d_type]
: "(bad d_type)");
}
diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index eb979e79eaac..62158c0803db 100644
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -9,6 +9,7 @@
#include "fsck.h"
#include "inode.h"
#include "keylist.h"
+#include "subvolume.h"
#include "super.h"
#include "xattr.h"
@@ -1410,7 +1411,8 @@ int bch2_fsck_full(struct bch_fs *c)
{
struct bch_inode_unpacked root_inode;
- return check_inodes(c, true) ?:
+ return bch2_fs_snapshots_check(c) ?:
+ check_inodes(c, true) ?:
check_extents(c) ?:
check_dirents(c) ?:
check_xattrs(c) ?:
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 2b653ee03f4f..3b19dc6b9ddc 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -8,6 +8,7 @@
#include "extents.h"
#include "inode.h"
#include "str_hash.h"
+#include "subvolume.h"
#include "varint.h"
#include <linux/random.h>
@@ -340,8 +341,8 @@ int bch2_inode_write(struct btree_trans *trans,
const char *bch2_inode_invalid(const struct bch_fs *c, struct bkey_s_c k)
{
- struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
- struct bch_inode_unpacked unpacked;
+ struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
+ struct bch_inode_unpacked unpacked;
if (k.k->p.inode)
return "nonzero k.p.inode";
@@ -368,6 +369,9 @@ const char *bch2_inode_invalid(const struct bch_fs *c, struct bkey_s_c k)
unpacked.bi_nlink != 0)
return "flagged as unlinked but bi_nlink != 0";
+ if (unpacked.bi_subvol && !S_ISDIR(unpacked.bi_mode))
+ return "subvolume root but not a directory";
+
return NULL;
}
@@ -635,6 +639,13 @@ retry:
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;
+ }
+
bkey_inode_generation_init(&delete.k_i);
delete.k.p = iter.pos;
delete.v.bi_generation = cpu_to_le32(inode_u.bi_generation + 1);
diff --git a/fs/bcachefs/opts.c b/fs/bcachefs/opts.c
index 5de296078219..ff99c6d24abd 100644
--- a/fs/bcachefs/opts.c
+++ b/fs/bcachefs/opts.c
@@ -63,7 +63,7 @@ const char * const bch2_member_states[] = {
#undef x
-const char * const bch2_d_types[DT_MAX] = {
+const char * const bch2_d_types[BCH_DT_MAX] = {
[DT_UNKNOWN] = "unknown",
[DT_FIFO] = "fifo",
[DT_CHR] = "chr",
@@ -73,6 +73,7 @@ const char * const bch2_d_types[DT_MAX] = {
[DT_LNK] = "lnk",
[DT_SOCK] = "sock",
[DT_WHT] = "whiteout",
+ [DT_SUBVOL] = "subvol",
};
void bch2_opts_apply(struct bch_opts *dst, struct bch_opts src)
diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 11208e83fabe..2aab57cf09e1 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -20,6 +20,7 @@
#include "quota.h"
#include "recovery.h"
#include "replicas.h"
+#include "subvolume.h"
#include "super-io.h"
#include <linux/sort.h>
@@ -961,6 +962,81 @@ fsck_err:
return ret;
}
+static int bch2_fs_initialize_subvolumes(struct bch_fs *c)
+{
+ struct bkey_i_snapshot root_snapshot;
+ struct bkey_i_subvolume root_volume;
+ int ret;
+
+ bkey_snapshot_init(&root_snapshot.k_i);
+ root_snapshot.k.p.offset = U32_MAX;
+ root_snapshot.v.flags = 0;
+ root_snapshot.v.parent = 0;
+ root_snapshot.v.subvol = BCACHEFS_ROOT_SUBVOL;
+ root_snapshot.v.pad = 0;
+ SET_BCH_SNAPSHOT_SUBVOL(&root_snapshot.v, true);
+
+ ret = bch2_btree_insert(c, BTREE_ID_snapshots,
+ &root_snapshot.k_i,
+ NULL, NULL, 0);
+ if (ret)
+ return ret;
+
+
+ bkey_subvolume_init(&root_volume.k_i);
+ root_volume.k.p.offset = BCACHEFS_ROOT_SUBVOL;
+ root_volume.v.flags = 0;
+ root_volume.v.snapshot = cpu_to_le32(U32_MAX);
+ root_volume.v.inode = cpu_to_le64(BCACHEFS_ROOT_INO);
+
+ ret = bch2_btree_insert(c, BTREE_ID_subvolumes,
+ &root_volume.k_i,
+ NULL, NULL, 0);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bch_inode_unpacked inode;
+ struct bkey_inode_buf *packed;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes,
+ POS(0, BCACHEFS_ROOT_INO), 0);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_inode) {
+ bch_err(c, "root inode not found");
+ ret = -ENOENT;
+ goto err;
+ }
+
+ ret = bch2_inode_unpack(bkey_s_c_to_inode(k), &inode);
+ BUG_ON(ret);
+
+ inode.bi_subvol = BCACHEFS_ROOT_SUBVOL;
+
+ packed = bch2_trans_kmalloc(trans, sizeof(*packed));
+ ret = PTR_ERR_OR_ZERO(packed);
+ if (ret)
+ goto err;
+
+ bch2_inode_pack(c, packed, &inode);
+ ret = bch2_trans_update(trans, &iter, &packed->inode.k_i, 0);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
int bch2_fs_recovery(struct bch_fs *c)
{
const char *err = "cannot allocate memory";
@@ -1017,11 +1093,12 @@ int bch2_fs_recovery(struct bch_fs *c)
c->opts.version_upgrade = true;
c->opts.fsck = true;
c->opts.fix_errors = FSCK_OPT_YES;
- }
-
- if (c->sb.version < bcachefs_metadata_version_btree_ptr_sectors_written) {
+ } else if (c->sb.version < bcachefs_metadata_version_btree_ptr_sectors_written) {
bch_info(c, "version prior to btree_ptr_sectors_written, upgrade required");
c->opts.version_upgrade = true;
+ } else if (c->sb.version < bcachefs_metadata_version_snapshot) {
+ bch_info(c, "filesystem version is prior to snapshot field - upgrading");
+ c->opts.version_upgrade = true;
}
ret = bch2_blacklist_table_initialize(c);
@@ -1190,6 +1267,29 @@ use_clean:
bch_verbose(c, "alloc write done");
}
+ if (c->sb.version < bcachefs_metadata_version_snapshot) {
+ err = "error creating root snapshot node";
+ ret = bch2_fs_initialize_subvolumes(c);
+ if (ret)
+ goto err;
+ }
+
+ bch_verbose(c, "reading snapshots table");
+ err = "error reading snapshots table";
+ ret = bch2_fs_snapshots_start(c);
+ if (ret)
+ goto err;
+ bch_verbose(c, "reading snapshots done");
+
+ if (c->sb.version < bcachefs_metadata_version_snapshot) {
+ /* set bi_subvol on root inode */
+ err = "error upgrade root inode for subvolumes";
+ ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
+ bch2_fs_upgrade_for_subvolumes(&trans));
+ if (ret)
+ goto err;
+ }
+
if (c->opts.fsck) {
bch_info(c, "starting fsck");
err = "error in fsck";
@@ -1350,9 +1450,22 @@ int bch2_fs_initialize(struct bch_fs *c)
}
}
+ err = "error creating root snapshot node";
+ ret = bch2_fs_initialize_subvolumes(c);
+ if (ret)
+ goto err;
+
+ bch_verbose(c, "reading snapshots table");
+ err = "error reading snapshots table";
+ ret = bch2_fs_snapshots_start(c);
+ if (ret)
+ goto err;
+ bch_verbose(c, "reading snapshots done");
+
bch2_inode_init(c, &root_inode, 0, 0,
S_IFDIR|S_IRWXU|S_IRUGO|S_IXUGO, 0, NULL);
- root_inode.bi_inum = BCACHEFS_ROOT_INO;
+ root_inode.bi_inum = BCACHEFS_ROOT_INO;
+ root_inode.bi_subvol = BCACHEFS_ROOT_SUBVOL;
bch2_inode_pack(c, &packed_inode, &root_inode);
packed_inode.inode.k.p.snapshot = U32_MAX;
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
new file mode 100644
index 000000000000..ff3b4d2d86b9
--- /dev/null
+++ b/fs/bcachefs/subvolume.c
@@ -0,0 +1,981 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "btree_key_cache.h"
+#include "btree_update.h"
+#include "error.h"
+#include "subvolume.h"
+
+/* Snapshot tree: */
+
+static void bch2_delete_dead_snapshots_work(struct work_struct *);
+static void bch2_delete_dead_snapshots(struct bch_fs *);
+
+void bch2_snapshot_to_text(struct printbuf *out, struct bch_fs *c,
+ struct bkey_s_c k)
+{
+ struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(k);
+
+ pr_buf(out, "is_subvol %llu deleted %llu parent %u children %u %u subvol %u",
+ BCH_SNAPSHOT_SUBVOL(s.v),
+ BCH_SNAPSHOT_DELETED(s.v),
+ le32_to_cpu(s.v->parent),
+ le32_to_cpu(s.v->children[0]),
+ le32_to_cpu(s.v->children[1]),
+ le32_to_cpu(s.v->subvol));
+}
+
+const char *bch2_snapshot_invalid(const struct bch_fs *c, struct bkey_s_c k)
+{
+ struct bkey_s_c_snapshot s;
+ u32 i, id;
+
+ if (bkey_cmp(k.k->p, POS(0, U32_MAX)) > 0 ||
+ bkey_cmp(k.k->p, POS(0, 1)) < 0)
+ return "bad pos";
+
+ if (bkey_val_bytes(k.k) != sizeof(struct bch_snapshot))
+ return "bad val size";
+
+ s = bkey_s_c_to_snapshot(k);
+
+ id = le32_to_cpu(s.v->parent);
+ if (id && id <= k.k->p.offset)
+ return "bad parent node";
+
+ if (le32_to_cpu(s.v->children[0]) < le32_to_cpu(s.v->children[1]))
+ return "children not normalized";
+
+ if (s.v->children[0] &&
+ s.v->children[0] == s.v->children[1])
+ return "duplicate child nodes";
+
+ for (i = 0; i < 2; i++) {
+ id = le32_to_cpu(s.v->children[i]);
+
+ if (id >= k.k->p.offset)
+ return "bad child node";
+ }
+
+ return NULL;
+}
+
+int bch2_mark_snapshot(struct bch_fs *c,
+ struct bkey_s_c old, struct bkey_s_c new,
+ u64 journal_seq, unsigned flags)
+{
+ struct snapshot_t *t;
+
+ t = genradix_ptr_alloc(&c->snapshots,
+ U32_MAX - new.k->p.offset,
+ GFP_KERNEL);
+ if (!t)
+ return -ENOMEM;
+
+ if (new.k->type == KEY_TYPE_snapshot) {
+ struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(new);
+
+ t->parent = le32_to_cpu(s.v->parent);
+ t->children[0] = le32_to_cpu(s.v->children[0]);
+ t->children[1] = le32_to_cpu(s.v->children[1]);
+ t->subvol = BCH_SNAPSHOT_SUBVOL(s.v) ? le32_to_cpu(s.v->subvol) : 0;
+ } else {
+ t->parent = 0;
+ t->children[0] = 0;
+ t->children[1] = 0;
+ t->subvol = 0;
+ }
+
+ return 0;
+}
+
+static int subvol_lookup(struct btree_trans *trans, unsigned id, struct bch_subvolume *s)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes, POS(0, id), 0);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k) ?: k.k->type == KEY_TYPE_subvolume ? 0 : -ENOENT;
+
+ if (!ret)
+ *s = *bkey_s_c_to_subvolume(k).v;
+
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int snapshot_lookup(struct btree_trans *trans, u32 id,
+ struct bch_snapshot *s)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
+ BTREE_ITER_WITH_UPDATES);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k) ?: k.k->type == KEY_TYPE_snapshot ? 0 : -ENOENT;
+
+ if (!ret)
+ *s = *bkey_s_c_to_snapshot(k).v;
+
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int snapshot_live(struct btree_trans *trans, u32 id)
+{
+ struct bch_snapshot v;
+ int ret;
+
+ if (!id)
+ return 0;
+
+ ret = lockrestart_do(trans, snapshot_lookup(trans, id, &v));
+ if (ret == -ENOENT)
+ bch_err(trans->c, "snapshot node %u not found", id);
+ if (ret)
+ return ret;
+
+ return !BCH_SNAPSHOT_DELETED(&v);
+}
+
+static int bch2_snapshots_set_equiv(struct btree_trans *trans)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_s_c_snapshot snap;
+ unsigned i;
+ int ret;
+
+ for_each_btree_key(trans, iter, BTREE_ID_snapshots,
+ POS_MIN, 0, k, ret) {
+ u32 id = k.k->p.offset, child[2];
+ unsigned nr_live = 0, live_idx;
+
+ if (k.k->type != KEY_TYPE_snapshot)
+ continue;
+
+ snap = bkey_s_c_to_snapshot(k);
+ child[0] = le32_to_cpu(snap.v->children[0]);
+ child[1] = le32_to_cpu(snap.v->children[1]);
+
+ for (i = 0; i < 2; i++) {
+ ret = snapshot_live(trans, child[i]);
+ if (ret < 0)
+ break;
+
+ if (ret)
+ live_idx = i;
+ nr_live += ret;
+ }
+
+ snapshot_t(c, id)->equiv = nr_live == 1
+ ? snapshot_t(c, child[live_idx])->equiv
+ : id;
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ if (ret)
+ bch_err(c, "error walking snapshots: %i", ret);
+
+ return ret;
+}
+
+/* fsck: */
+static int bch2_snapshot_check(struct btree_trans *trans,
+ struct bkey_s_c_snapshot s)
+{
+ struct bch_subvolume subvol;
+ struct bch_snapshot v;
+ u32 i, id;
+ int ret;
+
+ id = le32_to_cpu(s.v->subvol);
+ ret = lockrestart_do(trans, subvol_lookup(trans, id, &subvol));
+ if (ret == -ENOENT)
+ bch_err(trans->c, "snapshot node %llu has nonexistent subvolume %u",
+ s.k->p.offset, id);
+ if (ret)
+ return ret;
+
+ if (BCH_SNAPSHOT_SUBVOL(s.v) != (le32_to_cpu(subvol.snapshot) == s.k->p.offset)) {
+ bch_err(trans->c, "snapshot node %llu has wrong BCH_SNAPSHOT_SUBVOL",
+ s.k->p.offset);
+ return -EINVAL;
+ }
+
+ id = le32_to_cpu(s.v->parent);
+ if (id) {
+ ret = lockrestart_do(trans, snapshot_lookup(trans, id, &v));
+ if (ret == -ENOENT)
+ bch_err(trans->c, "snapshot node %llu has nonexistent parent %u",
+ s.k->p.offset, id);
+ if (ret)
+ return ret;
+
+ if (le32_to_cpu(v.children[0]) != s.k->p.offset &&
+ le32_to_cpu(v.children[1]) != s.k->p.offset) {
+ bch_err(trans->c, "snapshot parent %u missing pointer to child %llu",
+ id, s.k->p.offset);
+ return -EINVAL;
+ }
+ }
+
+ for (i = 0; i < 2 && s.v->children[i]; i++) {
+ id = le32_to_cpu(s.v->children[i]);
+
+ ret = lockrestart_do(trans, snapshot_lookup(trans, id, &v));
+ if (ret == -ENOENT)
+ bch_err(trans->c, "snapshot node %llu has nonexistent child %u",
+ s.k->p.offset, id);
+ if (ret)
+ return ret;
+
+ if (le32_to_cpu(v.parent) != s.k->p.offset) {
+ bch_err(trans->c, "snapshot child %u has wrong parent (got %u should be %llu)",
+ id, le32_to_cpu(v.parent), s.k->p.offset);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+int bch2_fs_snapshots_check(struct bch_fs *c)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bch_snapshot s;
+ unsigned id;
+ int ret;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ for_each_btree_key(&trans, iter, BTREE_ID_snapshots,
+ POS_MIN, 0, k, ret) {
+ if (k.k->type != KEY_TYPE_snapshot)
+ continue;
+
+ ret = bch2_snapshot_check(&trans, bkey_s_c_to_snapshot(k));
+ if (ret)
+ break;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ if (ret) {
+ bch_err(c, "error %i checking snapshots", ret);
+ goto err;
+ }
+
+ for_each_btree_key(&trans, iter, BTREE_ID_subvolumes,
+ POS_MIN, 0, k, ret) {
+ if (k.k->type != KEY_TYPE_subvolume)
+ continue;
+again_2:
+ id = le32_to_cpu(bkey_s_c_to_subvolume(k).v->snapshot);
+ ret = snapshot_lookup(&trans, id, &s);
+
+ if (ret == -EINTR) {
+ k = bch2_btree_iter_peek(&iter);
+ goto again_2;
+ } else if (ret == -ENOENT)
+ bch_err(c, "subvolume %llu points to nonexistent snapshot %u",
+ k.k->p.offset, id);
+ else if (ret)
+ break;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+err:
+ bch2_trans_exit(&trans);
+ return ret;
+}
+
+void bch2_fs_snapshots_exit(struct bch_fs *c)
+{
+ genradix_free(&c->snapshots);
+}
+
+int bch2_fs_snapshots_start(struct bch_fs *c)
+{
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ bool have_deleted = false;
+ int ret = 0;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ for_each_btree_key(&trans, iter, BTREE_ID_snapshots,
+ POS_MIN, 0, k, ret) {
+ if (bkey_cmp(k.k->p, POS(0, U32_MAX)) > 0)
+ break;
+
+ if (k.k->type != KEY_TYPE_snapshot) {
+ bch_err(c, "found wrong key type %u in snapshot node table",
+ k.k->type);
+ continue;
+ }
+
+ if (BCH_SNAPSHOT_DELETED(bkey_s_c_to_snapshot(k).v))
+ have_deleted = true;
+
+ ret = bch2_mark_snapshot(c, bkey_s_c_null, k, 0, 0);
+ if (ret)
+ break;
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ if (ret)
+ goto err;
+
+ ret = bch2_snapshots_set_equiv(&trans);
+ if (ret)
+ goto err;
+err:
+ bch2_trans_exit(&trans);
+
+ if (!ret && have_deleted) {
+ bch_info(c, "restarting deletion of dead snapshots");
+ if (c->opts.fsck) {
+ bch2_delete_dead_snapshots_work(&c->snapshot_delete_work);
+ } else {
+ bch2_delete_dead_snapshots(c);
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Mark a snapshot as deleted, for future cleanup:
+ */
+static int bch2_snapshot_node_set_deleted(struct btree_trans *trans, u32 id)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_i_snapshot *s;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_snapshot) {
+ bch2_fs_inconsistent(trans->c, "missing snapshot %u", id);
+ ret = -ENOENT;
+ goto err;
+ }
+
+ /* already deleted? */
+ if (BCH_SNAPSHOT_DELETED(bkey_s_c_to_snapshot(k).v))
+ goto err;
+
+ s = bch2_trans_kmalloc(trans, sizeof(*s));
+ ret = PTR_ERR_OR_ZERO(s);
+ if (ret)
+ goto err;
+
+ bkey_reassemble(&s->k_i, k);
+
+ SET_BCH_SNAPSHOT_DELETED(&s->v, true);
+ ret = bch2_trans_update(trans, &iter, &s->k_i, 0);
+ if (ret)
+ goto err;
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int bch2_snapshot_node_delete(struct btree_trans *trans, u32 id)
+{
+ struct btree_iter iter, p_iter = (struct btree_iter) { NULL };
+ struct bkey_s_c k;
+ struct bkey_s_c_snapshot s;
+ struct bkey_i_snapshot *parent;
+ u32 parent_id;
+ unsigned i;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots, POS(0, id),
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_snapshot) {
+ bch2_fs_inconsistent(trans->c, "missing snapshot %u", id);
+ ret = -ENOENT;
+ goto err;
+ }
+
+ s = bkey_s_c_to_snapshot(k);
+
+ BUG_ON(!BCH_SNAPSHOT_DELETED(s.v));
+ parent_id = le32_to_cpu(s.v->parent);
+
+ if (parent_id) {
+ bch2_trans_iter_init(trans, &p_iter, BTREE_ID_snapshots,
+ POS(0, parent_id),
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&p_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_snapshot) {
+ bch2_fs_inconsistent(trans->c, "missing snapshot %u", parent_id);
+ ret = -ENOENT;
+ goto err;
+ }
+
+ parent = bch2_trans_kmalloc(trans, sizeof(*parent));
+ ret = PTR_ERR_OR_ZERO(parent);
+ if (ret)
+ goto err;
+
+ bkey_reassemble(&parent->k_i, k);
+
+ for (i = 0; i < 2; i++)
+ if (le32_to_cpu(parent->v.children[i]) == id)
+ break;
+
+ if (i == 2)
+ bch_err(trans->c, "snapshot %u missing child pointer to %u",
+ parent_id, id);
+ else
+ parent->v.children[i] = 0;
+
+ if (le32_to_cpu(parent->v.children[0]) <
+ le32_to_cpu(parent->v.children[1]))
+ swap(parent->v.children[0],
+ parent->v.children[1]);
+
+ ret = bch2_trans_update(trans, &p_iter, &parent->k_i, 0);
+ if (ret)
+ goto err;
+ }
+
+ ret = bch2_btree_delete_at(trans, &iter, 0);
+err:
+ bch2_trans_iter_exit(trans, &p_iter);
+ bch2_trans_iter_exit(trans, &iter);
+ return ret;
+}
+
+static int bch2_snapshot_node_create(struct btree_trans *trans, u32 parent,
+ u32 *new_snapids,
+ u32 *snapshot_subvols,
+ unsigned nr_snapids)
+{
+ struct btree_iter iter;
+ struct bkey_i_snapshot *n;
+ struct bkey_s_c k;
+ unsigned i;
+ int ret = 0;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,
+ POS_MIN, BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ for (i = 0; i < nr_snapids; i++) {
+ k = bch2_btree_iter_prev_slot(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (!k.k || !k.k->p.offset) {
+ ret = -ENOSPC;
+ goto err;
+ }
+
+ n = bch2_trans_kmalloc(trans, sizeof(*n));
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ return ret;
+
+ bkey_snapshot_init(&n->k_i);
+ n->k.p = iter.pos;
+ n->v.flags = 0;
+ n->v.parent = cpu_to_le32(parent);
+ n->v.subvol = cpu_to_le32(snapshot_subvols[i]);
+ n->v.pad = 0;
+ SET_BCH_SNAPSHOT_SUBVOL(&n->v, true);
+
+ bch2_trans_update(trans, &iter, &n->k_i, 0);
+
+ ret = bch2_mark_snapshot(trans->c, bkey_s_c_null, bkey_i_to_s_c(&n->k_i), 0, 0);
+ if (ret)
+ break;
+
+ new_snapids[i] = iter.pos.offset;
+ }
+
+ if (parent) {
+ bch2_btree_iter_set_pos(&iter, POS(0, parent));
+ k = bch2_btree_iter_peek(&iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_snapshot) {
+ bch_err(trans->c, "snapshot %u not found", parent);
+ ret = -ENOENT;
+ goto err;
+ }
+
+ n = bch2_trans_kmalloc(trans, sizeof(*n));
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ return ret;
+
+ bkey_reassemble(&n->k_i, k);
+
+ if (n->v.children[0] || n->v.children[1]) {
+ bch_err(trans->c, "Trying to add child snapshot nodes to parent that already has children");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ n->v.children[0] = cpu_to_le32(new_snapids[0]);
+ n->v.children[1] = cpu_to_le32(new_snapids[1]);
+ SET_BCH_SNAPSHOT_SUBVOL(&n->v, false);
+ bch2_trans_update(trans, &iter, &n->k_i, 0);
+ }
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ 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;
+
+ for (i = 0; i < s->nr; i++)
+ if (id == s->d[i])
+ return true;
+ return false;
+}
+
+static int snapshot_id_add(struct snapshot_id_list *s, u32 id)
+{
+ BUG_ON(snapshot_list_has_id(s, id));
+
+ if (s->nr == s->size) {
+ size_t new_size = max(8U, s->size * 2);
+ void *n = krealloc(s->d,
+ new_size * sizeof(s->d[0]),
+ GFP_KERNEL);
+ if (!n) {
+ pr_err("error allocating snapshot ID list");
+ return -ENOMEM;
+ }
+
+ s->d = n;
+ s->size = new_size;
+ };
+
+ s->d[s->nr++] = id;
+ return 0;
+}
+
+static int bch2_snapshot_delete_keys_btree(struct btree_trans *trans,
+ struct snapshot_id_list *deleted,
+ enum btree_id btree_id)
+{
+ struct bch_fs *c = trans->c;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct snapshot_id_list equiv_seen = { 0 };
+ struct bpos last_pos = POS_MIN;
+ int ret = 0;
+
+ /*
+ * XXX: We should also delete whiteouts that no longer overwrite
+ * anything
+ */
+
+ bch2_trans_iter_init(trans, &iter, btree_id, POS_MIN,
+ BTREE_ITER_INTENT|
+ BTREE_ITER_PREFETCH|
+ BTREE_ITER_NOT_EXTENTS|
+ BTREE_ITER_ALL_SNAPSHOTS);
+
+ while ((bch2_trans_begin(trans),
+ (k = bch2_btree_iter_peek(&iter)).k) &&
+ !(ret = bkey_err(k))) {
+ u32 equiv = snapshot_t(c, k.k->p.snapshot)->equiv;
+
+ if (bkey_cmp(k.k->p, last_pos))
+ equiv_seen.nr = 0;
+ last_pos = k.k->p;
+
+ if (snapshot_list_has_id(deleted, k.k->p.snapshot) ||
+ snapshot_list_has_id(&equiv_seen, equiv)) {
+ if (btree_id == BTREE_ID_inodes &&
+ bch2_btree_key_cache_flush(trans, btree_id, iter.pos))
+ continue;
+
+ ret = __bch2_trans_do(trans, NULL, NULL,
+ BTREE_INSERT_NOFAIL,
+ bch2_btree_iter_traverse(&iter) ?:
+ bch2_btree_delete_at(trans, &iter,
+ BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE));
+ if (ret)
+ break;
+ } else {
+ ret = snapshot_id_add(&equiv_seen, equiv);
+ if (ret)
+ break;
+ }
+
+ bch2_btree_iter_advance(&iter);
+ }
+ bch2_trans_iter_exit(trans, &iter);
+
+ kfree(equiv_seen.d);
+
+ return ret;
+}
+
+static void bch2_delete_dead_snapshots_work(struct work_struct *work)
+{
+ struct bch_fs *c = container_of(work, struct bch_fs, snapshot_delete_work);
+ struct btree_trans trans;
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_s_c_snapshot snap;
+ struct snapshot_id_list deleted = { 0 };
+ u32 i, id, children[2];
+ int ret = 0;
+
+ bch2_trans_init(&trans, c, 0, 0);
+
+ /*
+ * For every snapshot node: If we have no live children and it's not
+ * pointed to by a subvolume, delete it:
+ */
+ for_each_btree_key(&trans, iter, BTREE_ID_snapshots,
+ POS_MIN, 0, k, ret) {
+ if (k.k->type != KEY_TYPE_snapshot)
+ continue;
+
+ snap = bkey_s_c_to_snapshot(k);
+ if (BCH_SNAPSHOT_DELETED(snap.v) ||
+ BCH_SNAPSHOT_SUBVOL(snap.v))
+ continue;
+
+ children[0] = le32_to_cpu(snap.v->children[0]);
+ children[1] = le32_to_cpu(snap.v->children[1]);
+
+ ret = snapshot_live(&trans, children[0]) ?:
+ snapshot_live(&trans, children[1]);
+ if (ret < 0)
+ break;
+ if (ret)
+ continue;
+
+ ret = __bch2_trans_do(&trans, NULL, NULL, 0,
+ bch2_snapshot_node_set_deleted(&trans, iter.pos.offset));
+ if (ret) {
+ bch_err(c, "error deleting snapshot %llu: %i", iter.pos.offset, ret);
+ break;
+ }
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ if (ret) {
+ bch_err(c, "error walking snapshots: %i", ret);
+ goto err;
+ }
+
+ ret = bch2_snapshots_set_equiv(&trans);
+ if (ret)
+ goto err;
+
+ for_each_btree_key(&trans, iter, BTREE_ID_snapshots,
+ POS_MIN, 0, k, ret) {
+ if (k.k->type != KEY_TYPE_snapshot)
+ continue;
+
+ snap = bkey_s_c_to_snapshot(k);
+ if (BCH_SNAPSHOT_DELETED(snap.v)) {
+ ret = snapshot_id_add(&deleted, k.k->p.offset);
+ if (ret)
+ break;
+ }
+ }
+ bch2_trans_iter_exit(&trans, &iter);
+
+ if (ret) {
+ bch_err(c, "error walking snapshots: %i", ret);
+ goto err;
+ }
+
+ for (id = 0; id < BTREE_ID_NR; id++) {
+ if (!btree_type_has_snapshots(id))
+ continue;
+
+ ret = bch2_snapshot_delete_keys_btree(&trans, &deleted, id);
+ if (ret) {
+ bch_err(c, "error deleting snapshot keys: %i", ret);
+ goto err;
+ }
+ }
+
+ for (i = 0; i < deleted.nr; i++) {
+ ret = __bch2_trans_do(&trans, NULL, NULL, 0,
+ bch2_snapshot_node_delete(&trans, deleted.d[i]));
+ if (ret) {
+ bch_err(c, "error deleting snapshot %u: %i",
+ deleted.d[i], ret);
+ goto err;
+ }
+ }
+err:
+ kfree(deleted.d);
+ bch2_trans_exit(&trans);
+ percpu_ref_put(&c->writes);
+}
+
+static void bch2_delete_dead_snapshots(struct bch_fs *c)
+{
+ if (unlikely(!percpu_ref_tryget(&c->writes)))
+ return;
+
+ if (!queue_work(system_long_wq, &c->snapshot_delete_work))
+ percpu_ref_put(&c->writes);
+}
+
+static int bch2_delete_dead_snapshots_hook(struct btree_trans *trans,
+ struct btree_trans_commit_hook *h)
+{
+ bch2_delete_dead_snapshots(trans->c);
+ return 0;
+}
+
+/* Subvolumes: */
+
+const char *bch2_subvolume_invalid(const struct bch_fs *c, struct bkey_s_c k)
+{
+ if (bkey_cmp(k.k->p, SUBVOL_POS_MIN) < 0)
+ return "invalid pos";
+
+ if (bkey_cmp(k.k->p, SUBVOL_POS_MAX) > 0)
+ return "invalid pos";
+
+ if (bkey_val_bytes(k.k) != sizeof(struct bch_subvolume))
+ return "bad val size";
+
+ return NULL;
+}
+
+void bch2_subvolume_to_text(struct printbuf *out, struct bch_fs *c,
+ struct bkey_s_c k)
+{
+ struct bkey_s_c_subvolume s = bkey_s_c_to_subvolume(k);
+
+ pr_buf(out, "root %llu snapshot id %u",
+ le64_to_cpu(s.v->inode),
+ le32_to_cpu(s.v->snapshot));
+}
+
+int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvol,
+ u32 *snapid)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ int ret;
+
+ bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
+ POS(0, subvol),
+ BTREE_ITER_CACHED|
+ BTREE_ITER_WITH_UPDATES);
+ 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", subvol);
+ ret = -EIO;
+ goto err;
+ }
+
+ *snapid = le32_to_cpu(bkey_s_c_to_subvolume(k).v->snapshot);
+err:
+ bch2_trans_iter_exit(trans, &iter);
+ 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)
+{
+ struct btree_iter iter;
+ struct bkey_s_c k;
+ struct bkey_s_c_subvolume subvol;
+ struct btree_trans_commit_hook *h;
+ struct bkey_i *delete;
+ u32 snapid;
+ 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;
+ }
+
+ 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)
+ goto err;
+
+ bkey_init(&delete->k);
+ delete->k.p = iter.pos;
+ ret = bch2_trans_update(trans, &iter, delete, 0);
+ if (ret)
+ goto err;
+
+ ret = bch2_snapshot_node_set_deleted(trans, snapid);
+
+ h = bch2_trans_kmalloc(trans, sizeof(*h));
+ ret = PTR_ERR_OR_ZERO(h);
+ if (ret)
+ goto err;
+
+ h->fn = bch2_delete_dead_snapshots_hook;
+ bch2_trans_commit_hook(trans, 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,
+ u32 *new_snapshotid,
+ bool ro)
+{
+ struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL };
+ struct bkey_i_subvolume *new_subvol = NULL;
+ struct bkey_i_subvolume *src_subvol = NULL;
+ struct bkey_s_c k;
+ u32 parent = 0, new_nodes[2], snapshot_subvols[2];
+ int ret = 0;
+
+ for_each_btree_key(trans, dst_iter, BTREE_ID_subvolumes, SUBVOL_POS_MIN,
+ BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
+ if (bkey_cmp(k.k->p, SUBVOL_POS_MAX) > 0)
+ break;
+ if (bkey_deleted(k.k))
+ goto found_slot;
+ }
+
+ if (!ret)
+ ret = -ENOSPC;
+ goto err;
+found_slot:
+ snapshot_subvols[0] = dst_iter.pos.offset;
+ snapshot_subvols[1] = src_subvolid;
+
+ if (src_subvolid) {
+ /* Creating a snapshot: */
+ src_subvol = bch2_trans_kmalloc(trans, sizeof(*src_subvol));
+ ret = PTR_ERR_OR_ZERO(src_subvol);
+ if (ret)
+ goto err;
+
+ bch2_trans_iter_init(trans, &src_iter, BTREE_ID_subvolumes,
+ POS(0, src_subvolid),
+ BTREE_ITER_CACHED|
+ BTREE_ITER_INTENT);
+ k = bch2_btree_iter_peek_slot(&src_iter);
+ ret = bkey_err(k);
+ if (ret)
+ goto err;
+
+ if (k.k->type != KEY_TYPE_subvolume) {
+ bch_err(trans->c, "subvolume %u not found", src_subvolid);
+ ret = -ENOENT;
+ goto err;
+ }
+
+ bkey_reassemble(&src_subvol->k_i, k);
+ parent = le32_to_cpu(src_subvol->v.snapshot);
+ }
+
+ ret = bch2_snapshot_node_create(trans, parent, new_nodes,
+ snapshot_subvols,
+ src_subvolid ? 2 : 1);
+ if (ret)
+ goto err;
+
+ if (src_subvolid) {
+ src_subvol->v.snapshot = cpu_to_le32(new_nodes[1]);
+ bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0);
+ }
+
+ new_subvol = bch2_trans_kmalloc(trans, sizeof(*new_subvol));
+ ret = PTR_ERR_OR_ZERO(new_subvol);
+ if (ret)
+ goto err;
+
+ bkey_subvolume_init(&new_subvol->k_i);
+ new_subvol->v.flags = 0;
+ new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]);
+ new_subvol->v.inode = cpu_to_le64(inode);
+ SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro);
+ SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 0);
+ new_subvol->k.p = dst_iter.pos;
+ bch2_trans_update(trans, &dst_iter, &new_subvol->k_i, 0);
+
+ *new_subvolid = new_subvol->k.p.offset;
+ *new_snapshotid = new_nodes[0];
+err:
+ bch2_trans_iter_exit(trans, &src_iter);
+ bch2_trans_iter_exit(trans, &dst_iter);
+ return ret;
+}
+
+int bch2_fs_subvolumes_init(struct bch_fs *c)
+{
+ INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work);
+ return 0;
+}
diff --git a/fs/bcachefs/subvolume.h b/fs/bcachefs/subvolume.h
new file mode 100644
index 000000000000..cea4c665af32
--- /dev/null
+++ b/fs/bcachefs/subvolume.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_SUBVOLUME_H
+#define _BCACHEFS_SUBVOLUME_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);
+
+#define bch2_bkey_ops_snapshot (struct bkey_ops) { \
+ .key_invalid = bch2_snapshot_invalid, \
+ .val_to_text = bch2_snapshot_to_text, \
+}
+
+int bch2_mark_snapshot(struct bch_fs *, struct bkey_s_c,
+ struct bkey_s_c, u64, unsigned);
+
+static inline struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
+{
+ return genradix_ptr(&c->snapshots, U32_MAX - id);
+}
+
+static inline u32 bch2_snapshot_parent(struct bch_fs *c, u32 id)
+{
+ return snapshot_t(c, id)->parent;
+}
+
+static inline u32 bch2_snapshot_internal_node(struct bch_fs *c, u32 id)
+{
+ struct snapshot_t *s = snapshot_t(c, id);
+
+ return s->children[0] || s->children[1];
+}
+
+static inline u32 bch2_snapshot_sibling(struct bch_fs *c, u32 id)
+{
+ struct snapshot_t *s;
+ u32 parent = bch2_snapshot_parent(c, id);
+
+ if (!parent)
+ return 0;
+
+ s = snapshot_t(c, bch2_snapshot_parent(c, id));
+ if (id == s->children[0])
+ return s->children[1];
+ if (id == s->children[1])
+ return s->children[0];
+ return 0;
+}
+
+static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
+{
+ while (id && id < ancestor)
+ id = bch2_snapshot_parent(c, id);
+
+ return id == ancestor;
+}
+
+int bch2_fs_snapshots_check(struct bch_fs *);
+void bch2_fs_snapshots_exit(struct bch_fs *);
+int bch2_fs_snapshots_start(struct bch_fs *);
+
+const char *bch2_subvolume_invalid(const struct bch_fs *, struct bkey_s_c);
+void bch2_subvolume_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
+
+#define bch2_bkey_ops_subvolume (struct bkey_ops) { \
+ .key_invalid = bch2_subvolume_invalid, \
+ .val_to_text = bch2_subvolume_to_text, \
+}
+
+int bch2_subvolume_get_snapshot(struct btree_trans *, u32, u32 *);
+
+int bch2_subvolume_delete(struct btree_trans *, u32, int);
+int bch2_subvolume_create(struct btree_trans *, u64, u32,
+ u32 *, u32 *, bool);
+
+int bch2_fs_subvolumes_init(struct bch_fs *);
+
+#endif /* _BCACHEFS_SUBVOLUME_H */
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index b18ca3947ac8..a861ec32dbde 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -39,6 +39,7 @@
#include "rebalance.h"
#include "recovery.h"
#include "replicas.h"
+#include "subvolume.h"
#include "super.h"
#include "super-io.h"
#include "sysfs.h"
@@ -475,6 +476,7 @@ static void __bch2_fs_free(struct bch_fs *c)
for (i = 0; i < BCH_TIME_STAT_NR; i++)
bch2_time_stats_exit(&c->times[i]);
+ bch2_fs_snapshots_exit(c);
bch2_fs_quota_exit(c);
bch2_fs_fsio_exit(c);
bch2_fs_ec_exit(c);
@@ -694,6 +696,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
mutex_init(&c->usage_scratch_lock);
mutex_init(&c->bio_bounce_pages_lock);
+ mutex_init(&c->snapshot_table_lock);
spin_lock_init(&c->btree_write_error_lock);
@@ -797,6 +800,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
bch2_fs_btree_key_cache_init(&c->btree_key_cache) ||
bch2_fs_btree_iter_init(c) ||
bch2_fs_btree_interior_update_init(c) ||
+ bch2_fs_subvolumes_init(c) ||
bch2_fs_io_init(c) ||
bch2_fs_encryption_init(c) ||
bch2_fs_compress_init(c) ||
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-16 18:15:47 +0300