diff options
Diffstat (limited to 'libbcachefs/fs-common.c')
| -rw-r--r-- | libbcachefs/fs-common.c | 631 |
1 files changed, 631 insertions, 0 deletions
diff --git a/libbcachefs/fs-common.c b/libbcachefs/fs-common.c new file mode 100644 index 00000000..dcaa47f6 --- /dev/null +++ b/libbcachefs/fs-common.c @@ -0,0 +1,631 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bcachefs.h" +#include "acl.h" +#include "btree_update.h" +#include "dirent.h" +#include "fs-common.h" +#include "inode.h" +#include "subvolume.h" +#include "xattr.h" + +#include <linux/posix_acl.h> + +static inline int is_subdir_for_nlink(struct bch_inode_unpacked *inode) +{ + return S_ISDIR(inode->bi_mode) && !inode->bi_subvol; +} + +int bch2_create_trans(struct btree_trans *trans, + subvol_inum dir, + struct bch_inode_unpacked *dir_u, + struct bch_inode_unpacked *new_inode, + const struct qstr *name, + uid_t uid, gid_t gid, umode_t mode, dev_t rdev, + struct posix_acl *default_acl, + struct posix_acl *acl, + subvol_inum snapshot_src, + unsigned flags) +{ + struct bch_fs *c = trans->c; + struct btree_iter dir_iter = { NULL }; + struct btree_iter inode_iter = { NULL }; + subvol_inum new_inum = dir; + u64 now = bch2_current_time(c); + u64 cpu = raw_smp_processor_id(); + u64 dir_target; + u32 snapshot; + unsigned dir_type = mode_to_type(mode); + int ret; + + ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &snapshot); + if (ret) + goto err; + + ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, + BTREE_ITER_intent|BTREE_ITER_with_updates); + if (ret) + goto err; + + if (!(flags & BCH_CREATE_SNAPSHOT)) { + /* Normal create path - allocate a new inode: */ + bch2_inode_init_late(new_inode, now, uid, gid, mode, rdev, dir_u); + + if (flags & BCH_CREATE_TMPFILE) + new_inode->bi_flags |= BCH_INODE_unlinked; + + ret = bch2_inode_create(trans, &inode_iter, new_inode, snapshot, cpu); + if (ret) + goto err; + + snapshot_src = (subvol_inum) { 0 }; + } else { + /* + * Creating a snapshot - we're not allocating a new inode, but + * we do have to lookup the root inode of the subvolume we're + * snapshotting and update it (in the new snapshot): + */ + + if (!snapshot_src.inum) { + /* Inode wasn't specified, just snapshot: */ + struct bch_subvolume s; + + ret = bch2_subvolume_get(trans, snapshot_src.subvol, true, + BTREE_ITER_cached, &s); + if (ret) + goto err; + + snapshot_src.inum = le64_to_cpu(s.inode); + } + + ret = bch2_inode_peek(trans, &inode_iter, new_inode, snapshot_src, + BTREE_ITER_intent); + if (ret) + goto err; + + if (new_inode->bi_subvol != snapshot_src.subvol) { + /* Not a subvolume root: */ + ret = -EINVAL; + goto err; + } + + /* + * If we're not root, we have to own the subvolume being + * snapshotted: + */ + if (uid && new_inode->bi_uid != uid) { + ret = -EPERM; + goto err; + } + + flags |= BCH_CREATE_SUBVOL; + } + + new_inum.inum = new_inode->bi_inum; + dir_target = new_inode->bi_inum; + + if (flags & BCH_CREATE_SUBVOL) { + u32 new_subvol, dir_snapshot; + + ret = bch2_subvolume_create(trans, new_inode->bi_inum, + dir.subvol, + snapshot_src.subvol, + &new_subvol, &snapshot, + (flags & BCH_CREATE_SNAPSHOT_RO) != 0); + if (ret) + goto err; + + new_inode->bi_parent_subvol = dir.subvol; + new_inode->bi_subvol = new_subvol; + new_inum.subvol = new_subvol; + dir_target = new_subvol; + dir_type = DT_SUBVOL; + + ret = bch2_subvolume_get_snapshot(trans, dir.subvol, &dir_snapshot); + if (ret) + goto err; + + bch2_btree_iter_set_snapshot(&dir_iter, dir_snapshot); + ret = bch2_btree_iter_traverse(&dir_iter); + if (ret) + goto err; + } + + if (!(flags & BCH_CREATE_SNAPSHOT)) { + if (default_acl) { + ret = bch2_set_acl_trans(trans, new_inum, new_inode, + default_acl, ACL_TYPE_DEFAULT); + if (ret) + goto err; + } + + if (acl) { + ret = bch2_set_acl_trans(trans, new_inum, new_inode, + acl, ACL_TYPE_ACCESS); + if (ret) + goto err; + } + } + + if (!(flags & BCH_CREATE_TMPFILE)) { + struct bch_hash_info dir_hash = bch2_hash_info_init(c, dir_u); + u64 dir_offset; + + if (is_subdir_for_nlink(new_inode)) + dir_u->bi_nlink++; + dir_u->bi_mtime = dir_u->bi_ctime = now; + + ret = bch2_inode_write(trans, &dir_iter, dir_u); + if (ret) + goto err; + + ret = bch2_dirent_create(trans, dir, &dir_hash, + dir_type, + name, + dir_target, + &dir_offset, + STR_HASH_must_create|BTREE_ITER_with_updates); + if (ret) + goto err; + + new_inode->bi_dir = dir_u->bi_inum; + new_inode->bi_dir_offset = dir_offset; + } + + inode_iter.flags &= ~BTREE_ITER_all_snapshots; + bch2_btree_iter_set_snapshot(&inode_iter, snapshot); + + ret = bch2_btree_iter_traverse(&inode_iter) ?: + bch2_inode_write(trans, &inode_iter, new_inode); +err: + bch2_trans_iter_exit(trans, &inode_iter); + bch2_trans_iter_exit(trans, &dir_iter); + return ret; +} + +int bch2_link_trans(struct btree_trans *trans, + subvol_inum dir, struct bch_inode_unpacked *dir_u, + subvol_inum inum, struct bch_inode_unpacked *inode_u, + const struct qstr *name) +{ + struct bch_fs *c = trans->c; + struct btree_iter dir_iter = { NULL }; + struct btree_iter inode_iter = { NULL }; + struct bch_hash_info dir_hash; + u64 now = bch2_current_time(c); + u64 dir_offset = 0; + int ret; + + if (dir.subvol != inum.subvol) + return -EXDEV; + + ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent); + if (ret) + return ret; + + inode_u->bi_ctime = now; + ret = bch2_inode_nlink_inc(inode_u); + if (ret) + goto err; + + ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent); + if (ret) + goto err; + + if (bch2_reinherit_attrs(inode_u, dir_u)) { + ret = -EXDEV; + goto err; + } + + dir_u->bi_mtime = dir_u->bi_ctime = now; + + dir_hash = bch2_hash_info_init(c, dir_u); + + ret = bch2_dirent_create(trans, dir, &dir_hash, + mode_to_type(inode_u->bi_mode), + name, inum.inum, &dir_offset, + STR_HASH_must_create); + if (ret) + goto err; + + inode_u->bi_dir = dir.inum; + inode_u->bi_dir_offset = dir_offset; + + ret = bch2_inode_write(trans, &dir_iter, dir_u) ?: + bch2_inode_write(trans, &inode_iter, inode_u); +err: + bch2_trans_iter_exit(trans, &dir_iter); + bch2_trans_iter_exit(trans, &inode_iter); + return ret; +} + +int bch2_unlink_trans(struct btree_trans *trans, + subvol_inum dir, + struct bch_inode_unpacked *dir_u, + struct bch_inode_unpacked *inode_u, + const struct qstr *name, + bool deleting_subvol) +{ + struct bch_fs *c = trans->c; + struct btree_iter dir_iter = { NULL }; + struct btree_iter dirent_iter = { NULL }; + struct btree_iter inode_iter = { NULL }; + struct bch_hash_info dir_hash; + subvol_inum inum; + u64 now = bch2_current_time(c); + struct bkey_s_c k; + int ret; + + ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent); + if (ret) + goto err; + + dir_hash = bch2_hash_info_init(c, dir_u); + + ret = bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash, + name, &inum, BTREE_ITER_intent); + if (ret) + goto err; + + ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, + BTREE_ITER_intent); + if (ret) + goto err; + + if (!deleting_subvol && S_ISDIR(inode_u->bi_mode)) { + ret = bch2_empty_dir_trans(trans, inum); + if (ret) + goto err; + } + + if (deleting_subvol && !inode_u->bi_subvol) { + ret = -BCH_ERR_ENOENT_not_subvol; + goto err; + } + + if (inode_u->bi_subvol) { + /* Recursive subvolume destroy not allowed (yet?) */ + ret = bch2_subvol_has_children(trans, inode_u->bi_subvol); + if (ret) + goto err; + } + + if (deleting_subvol || inode_u->bi_subvol) { + ret = bch2_subvolume_unlink(trans, inode_u->bi_subvol); + if (ret) + goto err; + + k = bch2_btree_iter_peek_slot(&dirent_iter); + ret = bkey_err(k); + if (ret) + goto err; + + /* + * If we're deleting a subvolume, we need to really delete the + * dirent, not just emit a whiteout in the current snapshot: + */ + bch2_btree_iter_set_snapshot(&dirent_iter, k.k->p.snapshot); + ret = bch2_btree_iter_traverse(&dirent_iter); + if (ret) + goto err; + } else { + bch2_inode_nlink_dec(trans, inode_u); + } + + if (inode_u->bi_dir == dirent_iter.pos.inode && + inode_u->bi_dir_offset == dirent_iter.pos.offset) { + inode_u->bi_dir = 0; + inode_u->bi_dir_offset = 0; + } + + dir_u->bi_mtime = dir_u->bi_ctime = inode_u->bi_ctime = now; + dir_u->bi_nlink -= is_subdir_for_nlink(inode_u); + + ret = bch2_hash_delete_at(trans, bch2_dirent_hash_desc, + &dir_hash, &dirent_iter, + BTREE_UPDATE_internal_snapshot_node) ?: + bch2_inode_write(trans, &dir_iter, dir_u) ?: + bch2_inode_write(trans, &inode_iter, inode_u); +err: + bch2_trans_iter_exit(trans, &inode_iter); + bch2_trans_iter_exit(trans, &dirent_iter); + bch2_trans_iter_exit(trans, &dir_iter); + return ret; +} + +bool bch2_reinherit_attrs(struct bch_inode_unpacked *dst_u, + struct bch_inode_unpacked *src_u) +{ + u64 src, dst; + unsigned id; + bool ret = false; + + for (id = 0; id < Inode_opt_nr; id++) { + /* Skip attributes that were explicitly set on this inode */ + if (dst_u->bi_fields_set & (1 << id)) + continue; + + src = bch2_inode_opt_get(src_u, id); + dst = bch2_inode_opt_get(dst_u, id); + + if (src == dst) + continue; + + bch2_inode_opt_set(dst_u, id, src); + ret = true; + } + + return ret; +} + +static int subvol_update_parent(struct btree_trans *trans, u32 subvol, u32 new_parent) +{ + struct btree_iter iter; + struct bkey_i_subvolume *s = + bch2_bkey_get_mut_typed(trans, &iter, + BTREE_ID_subvolumes, POS(0, subvol), + BTREE_ITER_cached, subvolume); + int ret = PTR_ERR_OR_ZERO(s); + if (ret) + return ret; + + s->v.fs_path_parent = cpu_to_le32(new_parent); + bch2_trans_iter_exit(trans, &iter); + return 0; +} + +int bch2_rename_trans(struct btree_trans *trans, + subvol_inum src_dir, struct bch_inode_unpacked *src_dir_u, + subvol_inum dst_dir, struct bch_inode_unpacked *dst_dir_u, + struct bch_inode_unpacked *src_inode_u, + struct bch_inode_unpacked *dst_inode_u, + const struct qstr *src_name, + const struct qstr *dst_name, + enum bch_rename_mode mode) +{ + struct bch_fs *c = trans->c; + struct btree_iter src_dir_iter = { NULL }; + struct btree_iter dst_dir_iter = { NULL }; + struct btree_iter src_inode_iter = { NULL }; + struct btree_iter dst_inode_iter = { NULL }; + struct bch_hash_info src_hash, dst_hash; + subvol_inum src_inum, dst_inum; + u64 src_offset, dst_offset; + u64 now = bch2_current_time(c); + int ret; + + ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir, + BTREE_ITER_intent); + if (ret) + goto err; + + src_hash = bch2_hash_info_init(c, src_dir_u); + + if (dst_dir.inum != src_dir.inum || + dst_dir.subvol != src_dir.subvol) { + ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir, + BTREE_ITER_intent); + if (ret) + goto err; + + dst_hash = bch2_hash_info_init(c, dst_dir_u); + } else { + dst_dir_u = src_dir_u; + dst_hash = src_hash; + } + + ret = bch2_dirent_rename(trans, + src_dir, &src_hash, + dst_dir, &dst_hash, + src_name, &src_inum, &src_offset, + dst_name, &dst_inum, &dst_offset, + mode); + if (ret) + goto err; + + ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum, + BTREE_ITER_intent); + if (ret) + goto err; + + if (dst_inum.inum) { + ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum, + BTREE_ITER_intent); + if (ret) + goto err; + } + + if (src_inode_u->bi_subvol && + dst_dir.subvol != src_inode_u->bi_parent_subvol) { + ret = subvol_update_parent(trans, src_inode_u->bi_subvol, dst_dir.subvol); + if (ret) + goto err; + } + + if (mode == BCH_RENAME_EXCHANGE && + dst_inode_u->bi_subvol && + src_dir.subvol != dst_inode_u->bi_parent_subvol) { + ret = subvol_update_parent(trans, dst_inode_u->bi_subvol, src_dir.subvol); + if (ret) + goto err; + } + + /* Can't move across subvolumes, unless it's a subvolume root: */ + if (src_dir.subvol != dst_dir.subvol && + (!src_inode_u->bi_subvol || + (dst_inum.inum && !dst_inode_u->bi_subvol))) { + ret = -EXDEV; + goto err; + } + + if (src_inode_u->bi_parent_subvol) + src_inode_u->bi_parent_subvol = dst_dir.subvol; + + if ((mode == BCH_RENAME_EXCHANGE) && + dst_inode_u->bi_parent_subvol) + dst_inode_u->bi_parent_subvol = src_dir.subvol; + + src_inode_u->bi_dir = dst_dir_u->bi_inum; + src_inode_u->bi_dir_offset = dst_offset; + + if (mode == BCH_RENAME_EXCHANGE) { + dst_inode_u->bi_dir = src_dir_u->bi_inum; + dst_inode_u->bi_dir_offset = src_offset; + } + + if (mode == BCH_RENAME_OVERWRITE && + dst_inode_u->bi_dir == dst_dir_u->bi_inum && + dst_inode_u->bi_dir_offset == src_offset) { + dst_inode_u->bi_dir = 0; + dst_inode_u->bi_dir_offset = 0; + } + + if (mode == BCH_RENAME_OVERWRITE) { + if (S_ISDIR(src_inode_u->bi_mode) != + S_ISDIR(dst_inode_u->bi_mode)) { + ret = -ENOTDIR; + goto err; + } + + if (S_ISDIR(dst_inode_u->bi_mode)) { + ret = bch2_empty_dir_trans(trans, dst_inum); + if (ret) + goto err; + } + } + + if (bch2_reinherit_attrs(src_inode_u, dst_dir_u) && + S_ISDIR(src_inode_u->bi_mode)) { + ret = -EXDEV; + goto err; + } + + if (mode == BCH_RENAME_EXCHANGE && + bch2_reinherit_attrs(dst_inode_u, src_dir_u) && + S_ISDIR(dst_inode_u->bi_mode)) { + ret = -EXDEV; + goto err; + } + + if (is_subdir_for_nlink(src_inode_u)) { + src_dir_u->bi_nlink--; + dst_dir_u->bi_nlink++; + } + + if (dst_inum.inum && is_subdir_for_nlink(dst_inode_u)) { + dst_dir_u->bi_nlink--; + src_dir_u->bi_nlink += mode == BCH_RENAME_EXCHANGE; + } + + if (mode == BCH_RENAME_OVERWRITE) + bch2_inode_nlink_dec(trans, dst_inode_u); + + src_dir_u->bi_mtime = now; + src_dir_u->bi_ctime = now; + + if (src_dir.inum != dst_dir.inum) { + dst_dir_u->bi_mtime = now; + dst_dir_u->bi_ctime = now; + } + + src_inode_u->bi_ctime = now; + + if (dst_inum.inum) + dst_inode_u->bi_ctime = now; + + ret = bch2_inode_write(trans, &src_dir_iter, src_dir_u) ?: + (src_dir.inum != dst_dir.inum + ? bch2_inode_write(trans, &dst_dir_iter, dst_dir_u) + : 0) ?: + bch2_inode_write(trans, &src_inode_iter, src_inode_u) ?: + (dst_inum.inum + ? bch2_inode_write(trans, &dst_inode_iter, dst_inode_u) + : 0); +err: + bch2_trans_iter_exit(trans, &dst_inode_iter); + bch2_trans_iter_exit(trans, &src_inode_iter); + bch2_trans_iter_exit(trans, &dst_dir_iter); + bch2_trans_iter_exit(trans, &src_dir_iter); + return ret; +} + +static inline void prt_bytes_reversed(struct printbuf *out, const void *b, unsigned n) +{ + bch2_printbuf_make_room(out, n); + + unsigned can_print = min(n, printbuf_remaining(out)); + + b += n; + + for (unsigned i = 0; i < can_print; i++) + out->buf[out->pos++] = *((char *) --b); + + printbuf_nul_terminate(out); +} + +static inline void reverse_bytes(void *b, size_t n) +{ + char *e = b + n, *s = b; + + while (s < e) { + --e; + swap(*s, *e); + s++; + } +} + +/* XXX: we don't yet attempt to print paths when we don't know the subvol */ +int bch2_inum_to_path(struct btree_trans *trans, subvol_inum inum, struct printbuf *path) +{ + unsigned orig_pos = path->pos; + int ret = 0; + + while (!(inum.subvol == BCACHEFS_ROOT_SUBVOL && + inum.inum == BCACHEFS_ROOT_INO)) { + struct bch_inode_unpacked inode; + ret = bch2_inode_find_by_inum_trans(trans, inum, &inode); + if (ret) + goto err; + + if (!inode.bi_dir && !inode.bi_dir_offset) { + ret = -BCH_ERR_ENOENT_inode_no_backpointer; + goto err; + } + + u32 snapshot; + ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); + if (ret) + goto err; + + struct btree_iter d_iter; + struct bkey_s_c_dirent d = bch2_bkey_get_iter_typed(trans, &d_iter, + BTREE_ID_dirents, SPOS(inode.bi_dir, inode.bi_dir_offset, snapshot), + 0, dirent); + ret = bkey_err(d.s_c); + if (ret) + goto err; + + struct qstr dirent_name = bch2_dirent_get_name(d); + prt_bytes_reversed(path, dirent_name.name, dirent_name.len); + + prt_char(path, '/'); + + if (d.v->d_type == DT_SUBVOL) + inum.subvol = le32_to_cpu(d.v->d_parent_subvol); + inum.inum = d.k->p.inode; + + bch2_trans_iter_exit(trans, &d_iter); + } + + if (orig_pos == path->pos) + prt_char(path, '/'); + + ret = path->allocation_failure ? -ENOMEM : 0; + if (ret) + goto err; + + reverse_bytes(path->buf + orig_pos, path->pos - orig_pos); + return 0; +err: + return ret; +} |