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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:39:57 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-18 17:39:57 +0000 |
commit | dc50eab76b709d68175a358d6e23a5a3890764d3 (patch) | |
tree | c754d0390db060af0213ff994f0ac310e4cfd6e9 /fs/bcachefs/subvolume.c | |
parent | Adding debian version 6.6.15-2. (diff) | |
download | linux-dc50eab76b709d68175a358d6e23a5a3890764d3.tar.xz linux-dc50eab76b709d68175a358d6e23a5a3890764d3.zip |
Merging upstream version 6.7.7.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/bcachefs/subvolume.c')
-rw-r--r-- | fs/bcachefs/subvolume.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c new file mode 100644 index 0000000000..22b34a8e4d --- /dev/null +++ b/fs/bcachefs/subvolume.c @@ -0,0 +1,455 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bcachefs.h" +#include "btree_key_cache.h" +#include "btree_update.h" +#include "errcode.h" +#include "error.h" +#include "fs.h" +#include "snapshot.h" +#include "subvolume.h" + +#include <linux/random.h> + +static int bch2_subvolume_delete(struct btree_trans *, u32); + +static int check_subvol(struct btree_trans *trans, + struct btree_iter *iter, + struct bkey_s_c k) +{ + struct bch_fs *c = trans->c; + struct bkey_s_c_subvolume subvol; + struct bch_snapshot snapshot; + unsigned snapid; + int ret = 0; + + if (k.k->type != KEY_TYPE_subvolume) + return 0; + + subvol = bkey_s_c_to_subvolume(k); + snapid = le32_to_cpu(subvol.v->snapshot); + ret = bch2_snapshot_lookup(trans, snapid, &snapshot); + + if (bch2_err_matches(ret, ENOENT)) + bch_err(c, "subvolume %llu points to nonexistent snapshot %u", + k.k->p.offset, snapid); + if (ret) + return ret; + + if (BCH_SUBVOLUME_UNLINKED(subvol.v)) { + bch2_fs_lazy_rw(c); + + ret = bch2_subvolume_delete(trans, iter->pos.offset); + if (ret) + bch_err_msg(c, ret, "deleting subvolume %llu", iter->pos.offset); + return ret ?: -BCH_ERR_transaction_restart_nested; + } + + if (!BCH_SUBVOLUME_SNAP(subvol.v)) { + u32 snapshot_root = bch2_snapshot_root(c, le32_to_cpu(subvol.v->snapshot)); + u32 snapshot_tree; + struct bch_snapshot_tree st; + + rcu_read_lock(); + snapshot_tree = snapshot_t(c, snapshot_root)->tree; + rcu_read_unlock(); + + ret = bch2_snapshot_tree_lookup(trans, snapshot_tree, &st); + + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, + "%s: snapshot tree %u not found", __func__, snapshot_tree); + + if (ret) + return ret; + + if (fsck_err_on(le32_to_cpu(st.master_subvol) != subvol.k->p.offset, + c, subvol_not_master_and_not_snapshot, + "subvolume %llu is not set as snapshot but is not master subvolume", + k.k->p.offset)) { + struct bkey_i_subvolume *s = + bch2_bkey_make_mut_typed(trans, iter, &subvol.s_c, 0, subvolume); + ret = PTR_ERR_OR_ZERO(s); + if (ret) + return ret; + + SET_BCH_SUBVOLUME_SNAP(&s->v, true); + } + } + +fsck_err: + return ret; +} + +int bch2_check_subvols(struct bch_fs *c) +{ + struct btree_iter iter; + struct bkey_s_c k; + int ret; + + ret = bch2_trans_run(c, + for_each_btree_key_commit(trans, iter, + BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k, + NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL, + check_subvol(trans, &iter, k))); + if (ret) + bch_err_fn(c, ret); + return ret; +} + +/* Subvolumes: */ + +int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k, + enum bkey_invalid_flags flags, struct printbuf *err) +{ + int ret = 0; + + bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) || + bkey_gt(k.k->p, SUBVOL_POS_MAX), c, err, + subvol_pos_bad, + "invalid pos"); +fsck_err: + return ret; +} + +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); + + prt_printf(out, "root %llu snapshot id %u", + le64_to_cpu(s.v->inode), + le32_to_cpu(s.v->snapshot)); + + if (bkey_val_bytes(s.k) > offsetof(struct bch_subvolume, parent)) + prt_printf(out, " parent %u", le32_to_cpu(s.v->parent)); +} + +static __always_inline int +bch2_subvolume_get_inlined(struct btree_trans *trans, unsigned subvol, + bool inconsistent_if_not_found, + int iter_flags, + struct bch_subvolume *s) +{ + int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_subvolumes, POS(0, subvol), + iter_flags, subvolume, s); + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT) && + inconsistent_if_not_found, + trans->c, "missing subvolume %u", subvol); + return ret; +} + +int bch2_subvolume_get(struct btree_trans *trans, unsigned subvol, + bool inconsistent_if_not_found, + int iter_flags, + struct bch_subvolume *s) +{ + return bch2_subvolume_get_inlined(trans, subvol, inconsistent_if_not_found, iter_flags, s); +} + +int bch2_subvol_is_ro_trans(struct btree_trans *trans, u32 subvol) +{ + struct bch_subvolume s; + int ret = bch2_subvolume_get_inlined(trans, subvol, true, 0, &s); + if (ret) + return ret; + + if (BCH_SUBVOLUME_RO(&s)) + return -EROFS; + return 0; +} + +int bch2_subvol_is_ro(struct bch_fs *c, u32 subvol) +{ + return bch2_trans_do(c, NULL, NULL, 0, + bch2_subvol_is_ro_trans(trans, subvol)); +} + +int bch2_snapshot_get_subvol(struct btree_trans *trans, u32 snapshot, + struct bch_subvolume *subvol) +{ + struct bch_snapshot snap; + + return bch2_snapshot_lookup(trans, snapshot, &snap) ?: + bch2_subvolume_get(trans, le32_to_cpu(snap.subvol), true, 0, subvol); +} + +int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid, + u32 *snapid) +{ + struct btree_iter iter; + struct bkey_s_c_subvolume subvol; + int ret; + + subvol = bch2_bkey_get_iter_typed(trans, &iter, + BTREE_ID_subvolumes, POS(0, subvolid), + BTREE_ITER_CACHED|BTREE_ITER_WITH_UPDATES, + subvolume); + ret = bkey_err(subvol); + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, + "missing subvolume %u", subvolid); + + if (likely(!ret)) + *snapid = le32_to_cpu(subvol.v->snapshot); + bch2_trans_iter_exit(trans, &iter); + return ret; +} + +static int bch2_subvolume_reparent(struct btree_trans *trans, + struct btree_iter *iter, + struct bkey_s_c k, + u32 old_parent, u32 new_parent) +{ + struct bkey_i_subvolume *s; + int ret; + + if (k.k->type != KEY_TYPE_subvolume) + return 0; + + if (bkey_val_bytes(k.k) > offsetof(struct bch_subvolume, parent) && + le32_to_cpu(bkey_s_c_to_subvolume(k).v->parent) != old_parent) + return 0; + + s = bch2_bkey_make_mut_typed(trans, iter, &k, 0, subvolume); + ret = PTR_ERR_OR_ZERO(s); + if (ret) + return ret; + + s->v.parent = cpu_to_le32(new_parent); + return 0; +} + +/* + * Separate from the snapshot tree in the snapshots btree, we record the tree + * structure of how snapshot subvolumes were created - the parent subvolume of + * each snapshot subvolume. + * + * When a subvolume is deleted, we scan for child subvolumes and reparant them, + * to avoid dangling references: + */ +static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_delete) +{ + struct btree_iter iter; + struct bkey_s_c k; + struct bch_subvolume s; + + return lockrestart_do(trans, + bch2_subvolume_get(trans, subvolid_to_delete, true, + BTREE_ITER_CACHED, &s)) ?: + for_each_btree_key_commit(trans, iter, + BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k, + NULL, NULL, BTREE_INSERT_NOFAIL, + bch2_subvolume_reparent(trans, &iter, k, + subvolid_to_delete, le32_to_cpu(s.parent))); +} + +/* + * Delete subvolume, mark snapshot ID as deleted, queue up snapshot + * deletion/cleanup: + */ +static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) +{ + struct btree_iter iter; + struct bkey_s_c_subvolume subvol; + u32 snapid; + int ret = 0; + + subvol = bch2_bkey_get_iter_typed(trans, &iter, + BTREE_ID_subvolumes, POS(0, subvolid), + BTREE_ITER_CACHED|BTREE_ITER_INTENT, + subvolume); + ret = bkey_err(subvol); + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, + "missing subvolume %u", subvolid); + if (ret) + return ret; + + snapid = le32_to_cpu(subvol.v->snapshot); + + ret = bch2_btree_delete_at(trans, &iter, 0) ?: + bch2_snapshot_node_set_deleted(trans, snapid); + bch2_trans_iter_exit(trans, &iter); + return ret; +} + +static int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid) +{ + return bch2_subvolumes_reparent(trans, subvolid) ?: + commit_do(trans, NULL, NULL, BTREE_INSERT_NOFAIL, + __bch2_subvolume_delete(trans, subvolid)); +} + +static 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); + snapshot_id_list s; + u32 *id; + int ret = 0; + + while (!ret) { + mutex_lock(&c->snapshots_unlinked_lock); + s = c->snapshots_unlinked; + darray_init(&c->snapshots_unlinked); + mutex_unlock(&c->snapshots_unlinked_lock); + + if (!s.nr) + break; + + bch2_evict_subvolume_inodes(c, &s); + + for (id = s.data; id < s.data + s.nr; id++) { + ret = bch2_trans_run(c, bch2_subvolume_delete(trans, *id)); + if (ret) { + bch_err_msg(c, ret, "deleting subvolume %u", *id); + break; + } + } + + darray_exit(&s); + } + + bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache); +} + +struct subvolume_unlink_hook { + struct btree_trans_commit_hook h; + u32 subvol; +}; + +static 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_list_add(c, &c->snapshots_unlinked, h->subvol); + mutex_unlock(&c->snapshots_unlinked_lock); + + if (ret) + return ret; + + if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_snapshot_delete_pagecache)) + return -EROFS; + + if (!queue_work(c->write_ref_wq, &c->snapshot_wait_for_pagecache_and_delete_work)) + bch2_write_ref_put(c, BCH_WRITE_REF_snapshot_delete_pagecache); + return 0; +} + +int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid) +{ + struct btree_iter iter; + struct bkey_i_subvolume *n; + struct subvolume_unlink_hook *h; + int ret = 0; + + h = bch2_trans_kmalloc(trans, sizeof(*h)); + ret = PTR_ERR_OR_ZERO(h); + if (ret) + return ret; + + h->h.fn = bch2_subvolume_wait_for_pagecache_and_delete_hook; + h->subvol = subvolid; + bch2_trans_commit_hook(trans, &h->h); + + n = bch2_bkey_get_mut_typed(trans, &iter, + BTREE_ID_subvolumes, POS(0, subvolid), + BTREE_ITER_CACHED, subvolume); + ret = PTR_ERR_OR_ZERO(n); + if (unlikely(ret)) { + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c, + "missing subvolume %u", subvolid); + return ret; + } + + SET_BCH_SUBVOLUME_UNLINKED(&n->v, true); + 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 bch_fs *c = trans->c; + 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; + u32 parent = 0, new_nodes[2], snapshot_subvols[2]; + int ret = 0; + + ret = bch2_bkey_get_empty_slot(trans, &dst_iter, + BTREE_ID_subvolumes, POS(0, U32_MAX)); + if (ret == -BCH_ERR_ENOSPC_btree_slot) + ret = -BCH_ERR_ENOSPC_subvolume_create; + if (ret) + return ret; + + snapshot_subvols[0] = dst_iter.pos.offset; + snapshot_subvols[1] = src_subvolid; + + if (src_subvolid) { + /* Creating a snapshot: */ + + src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter, + BTREE_ID_subvolumes, POS(0, src_subvolid), + BTREE_ITER_CACHED, subvolume); + ret = PTR_ERR_OR_ZERO(src_subvol); + if (unlikely(ret)) { + bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c, + "subvolume %u not found", src_subvolid); + goto err; + } + + 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]); + ret = bch2_trans_update(trans, &src_iter, &src_subvol->k_i, 0); + if (ret) + goto err; + } + + new_subvol = bch2_bkey_alloc(trans, &dst_iter, 0, subvolume); + ret = PTR_ERR_OR_ZERO(new_subvol); + if (ret) + goto err; + + new_subvol->v.flags = 0; + new_subvol->v.snapshot = cpu_to_le32(new_nodes[0]); + new_subvol->v.inode = cpu_to_le64(inode); + new_subvol->v.parent = cpu_to_le32(src_subvolid); + new_subvol->v.otime.lo = cpu_to_le64(bch2_current_time(c)); + new_subvol->v.otime.hi = 0; + + SET_BCH_SUBVOLUME_RO(&new_subvol->v, ro); + SET_BCH_SUBVOLUME_SNAP(&new_subvol->v, src_subvolid != 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); + 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; +} |