/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "alloc-util.h" #include "blockdev-util.h" #include "btrfs-util.h" #include "chase.h" #include "chattr-util.h" #include "copy.h" #include "fd-util.h" #include "fileio.h" #include "fs-util.h" #include "io-util.h" #include "macro.h" #include "path-util.h" #include "rm-rf.h" #include "smack-util.h" #include "sparse-endian.h" #include "stat-util.h" #include "string-util.h" #include "time-util.h" /* WARNING: Be careful with file system ioctls! When we get an fd, we * need to make sure it either refers to only a regular file or * directory, or that it is located on btrfs, before invoking any * btrfs ioctls. The ioctl numbers are reused by some device drivers * (such as DRM), and hence might have bad effects when invoked on * device nodes (that reference drivers) rather than fds to normal * files or directories. */ int btrfs_is_subvol_at(int dir_fd, const char *path) { struct stat st; assert(dir_fd >= 0 || dir_fd == AT_FDCWD); /* On btrfs subvolumes always have the inode 256 */ if (fstatat(dir_fd, strempty(path), &st, isempty(path) ? AT_EMPTY_PATH : 0) < 0) return -errno; if (!btrfs_might_be_subvol(&st)) return 0; return is_fs_type_at(dir_fd, path, BTRFS_SUPER_MAGIC); } int btrfs_subvol_set_read_only_at(int dir_fd, const char *path, bool b) { _cleanup_close_ int fd = -EBADF; uint64_t flags, nflags; struct stat st; assert(dir_fd >= 0 || dir_fd == AT_FDCWD); fd = xopenat(dir_fd, path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); if (fd < 0) return fd; if (fstat(fd, &st) < 0) return -errno; if (!btrfs_might_be_subvol(&st)) return -EINVAL; if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0) return -errno; nflags = UPDATE_FLAG(flags, BTRFS_SUBVOL_RDONLY, b); if (flags == nflags) return 0; return RET_NERRNO(ioctl(fd, BTRFS_IOC_SUBVOL_SETFLAGS, &nflags)); } int btrfs_subvol_get_read_only_fd(int fd) { uint64_t flags; struct stat st; assert(fd >= 0); if (fstat(fd, &st) < 0) return -errno; if (!btrfs_might_be_subvol(&st)) return -EINVAL; if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0) return -errno; return !!(flags & BTRFS_SUBVOL_RDONLY); } int btrfs_get_block_device_at(int dir_fd, const char *path, dev_t *ret) { struct btrfs_ioctl_fs_info_args fsi = {}; _cleanup_close_ int fd = -EBADF; uint64_t id; int r; assert(dir_fd >= 0 || dir_fd == AT_FDCWD); assert(path); assert(ret); fd = xopenat(dir_fd, path, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); if (fd < 0) return fd; r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; if (ioctl(fd, BTRFS_IOC_FS_INFO, &fsi) < 0) return -errno; /* We won't do this for btrfs RAID */ if (fsi.num_devices != 1) { *ret = 0; return 0; } for (id = 1; id <= fsi.max_id; id++) { struct btrfs_ioctl_dev_info_args di = { .devid = id, }; struct stat st; if (ioctl(fd, BTRFS_IOC_DEV_INFO, &di) < 0) { if (errno == ENODEV) continue; return -errno; } /* For the root fs — when no initrd is involved — btrfs returns /dev/root on any kernels from * the past few years. That sucks, as we have no API to determine the actual root then. let's * return an recognizable error for this case, so that the caller can maybe print a nice * message about this. * * https://bugzilla.kernel.org/show_bug.cgi?id=89721 */ if (path_equal((char*) di.path, "/dev/root")) return -EUCLEAN; if (stat((char*) di.path, &st) < 0) return -errno; if (!S_ISBLK(st.st_mode)) return -ENOTBLK; if (major(st.st_rdev) == 0) return -ENODEV; *ret = st.st_rdev; return 1; } return -ENODEV; } int btrfs_subvol_get_id_fd(int fd, uint64_t *ret) { struct btrfs_ioctl_ino_lookup_args args = { .objectid = BTRFS_FIRST_FREE_OBJECTID }; int r; assert(fd >= 0); assert(ret); r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args) < 0) return -errno; *ret = args.treeid; return 0; } int btrfs_subvol_get_id(int fd, const char *subvol, uint64_t *ret) { _cleanup_close_ int subvol_fd = -EBADF; assert(fd >= 0); assert(ret); subvol_fd = openat(fd, subvol, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (subvol_fd < 0) return -errno; return btrfs_subvol_get_id_fd(subvol_fd, ret); } static bool btrfs_ioctl_search_args_inc(struct btrfs_ioctl_search_args *args) { assert(args); /* the objectid, type, offset together make up the btrfs key, * which is considered a single 136byte integer when * comparing. This call increases the counter by one, dealing * with the overflow between the overflows */ if (args->key.min_offset < UINT64_MAX) { args->key.min_offset++; return true; } if (args->key.min_type < UINT8_MAX) { args->key.min_type++; args->key.min_offset = 0; return true; } if (args->key.min_objectid < UINT64_MAX) { args->key.min_objectid++; args->key.min_offset = 0; args->key.min_type = 0; return true; } return 0; } static void btrfs_ioctl_search_args_set(struct btrfs_ioctl_search_args *args, const struct btrfs_ioctl_search_header *h) { assert(args); assert(h); args->key.min_objectid = h->objectid; args->key.min_type = h->type; args->key.min_offset = h->offset; } static int btrfs_ioctl_search_args_compare(const struct btrfs_ioctl_search_args *args) { int r; assert(args); /* Compare min and max */ r = CMP(args->key.min_objectid, args->key.max_objectid); if (r != 0) return r; r = CMP(args->key.min_type, args->key.max_type); if (r != 0) return r; return CMP(args->key.min_offset, args->key.max_offset); } typedef struct BtrfsForeachIterator { const struct btrfs_ioctl_search_args *args; size_t offset; unsigned index; struct btrfs_ioctl_search_header *header; const void **body; } BtrfsForeachIterator; static int btrfs_iterate(BtrfsForeachIterator *i) { assert(i); assert(i->args); assert(i->header); assert(i->body); if (i->index >= i->args->key.nr_items) return 0; /* end */ assert_cc(BTRFS_SEARCH_ARGS_BUFSIZE >= sizeof(struct btrfs_ioctl_search_header)); if (i->offset > BTRFS_SEARCH_ARGS_BUFSIZE - sizeof(struct btrfs_ioctl_search_header)) return -EBADMSG; struct btrfs_ioctl_search_header h; memcpy(&h, (const uint8_t*) i->args->buf + i->offset, sizeof(struct btrfs_ioctl_search_header)); if (i->offset > BTRFS_SEARCH_ARGS_BUFSIZE - sizeof(struct btrfs_ioctl_search_header) - h.len) return -EBADMSG; *i->body = (const uint8_t*) i->args->buf + i->offset + sizeof(struct btrfs_ioctl_search_header); *i->header = h; i->offset += sizeof(struct btrfs_ioctl_search_header) + h.len; i->index++; return 1; } /* Iterates through a series of struct btrfs_file_extent_item elements. They are unfortunately not aligned, * hence we copy out the header from them */ #define FOREACH_BTRFS_IOCTL_SEARCH_HEADER(_sh, _body, _args) \ for (BtrfsForeachIterator iterator = { \ .args = &(_args), \ .header = &(_sh), \ .body = &(_body), \ }; \ btrfs_iterate(&iterator) > 0; ) int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *ret) { struct btrfs_ioctl_search_args args = { /* Tree of tree roots */ .key.tree_id = BTRFS_ROOT_TREE_OBJECTID, /* Look precisely for the subvolume items */ .key.min_type = BTRFS_ROOT_ITEM_KEY, .key.max_type = BTRFS_ROOT_ITEM_KEY, .key.min_offset = 0, .key.max_offset = UINT64_MAX, /* No restrictions on the other components */ .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; bool found = false; int r; assert(fd >= 0); assert(ret); if (subvol_id == 0) { r = btrfs_subvol_get_id_fd(fd, &subvol_id); if (r < 0) return r; } else { r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; } args.key.min_objectid = args.key.max_objectid = subvol_id; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) return -errno; if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { /* Make sure we start the next search at least from this entry */ btrfs_ioctl_search_args_set(&args, &sh); if (sh.objectid != subvol_id) continue; if (sh.type != BTRFS_ROOT_ITEM_KEY) continue; /* Older versions of the struct lacked the otime setting */ if (sh.len < offsetof(struct btrfs_root_item, otime) + sizeof(struct btrfs_timespec)) continue; const struct btrfs_root_item *ri = body; ret->otime = (usec_t) le64toh(ri->otime.sec) * USEC_PER_SEC + (usec_t) le32toh(ri->otime.nsec) / NSEC_PER_USEC; ret->subvol_id = subvol_id; ret->read_only = le64toh(ri->flags) & BTRFS_ROOT_SUBVOL_RDONLY; assert_cc(sizeof(ri->uuid) == sizeof(ret->uuid)); memcpy(&ret->uuid, ri->uuid, sizeof(ret->uuid)); memcpy(&ret->parent_uuid, ri->parent_uuid, sizeof(ret->parent_uuid)); found = true; goto finish; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } finish: return found ? 0 : -ENODATA; } int btrfs_qgroup_get_quota_fd(int fd, uint64_t qgroupid, BtrfsQuotaInfo *ret) { struct btrfs_ioctl_search_args args = { /* Tree of quota items */ .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID, /* The object ID is always 0 */ .key.min_objectid = 0, .key.max_objectid = 0, /* Look precisely for the quota items */ .key.min_type = BTRFS_QGROUP_STATUS_KEY, .key.max_type = BTRFS_QGROUP_LIMIT_KEY, /* No restrictions on the other components */ .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; bool found_info = false, found_limit = false; int r; assert(fd >= 0); assert(ret); if (qgroupid == 0) { r = btrfs_subvol_get_id_fd(fd, &qgroupid); if (r < 0) return r; } else { r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; } args.key.min_offset = args.key.max_offset = qgroupid; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) { if (errno == ENOENT) /* quota tree is missing: quota disabled */ break; return -errno; } if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { /* Make sure we start the next search at least from this entry */ btrfs_ioctl_search_args_set(&args, &sh); if (sh.objectid != 0) continue; if (sh.offset != qgroupid) continue; if (sh.type == BTRFS_QGROUP_INFO_KEY) { const struct btrfs_qgroup_info_item *qii = body; ret->referenced = le64toh(qii->rfer); ret->exclusive = le64toh(qii->excl); found_info = true; } else if (sh.type == BTRFS_QGROUP_LIMIT_KEY) { const struct btrfs_qgroup_limit_item *qli = body; if (le64toh(qli->flags) & BTRFS_QGROUP_LIMIT_MAX_RFER) ret->referenced_max = le64toh(qli->max_rfer); else ret->referenced_max = UINT64_MAX; if (le64toh(qli->flags) & BTRFS_QGROUP_LIMIT_MAX_EXCL) ret->exclusive_max = le64toh(qli->max_excl); else ret->exclusive_max = UINT64_MAX; found_limit = true; } if (found_info && found_limit) goto finish; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } finish: if (!found_limit && !found_info) return -ENODATA; if (!found_info) { ret->referenced = UINT64_MAX; ret->exclusive = UINT64_MAX; } if (!found_limit) { ret->referenced_max = UINT64_MAX; ret->exclusive_max = UINT64_MAX; } return 0; } int btrfs_qgroup_get_quota(const char *path, uint64_t qgroupid, BtrfsQuotaInfo *ret) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_qgroup_get_quota_fd(fd, qgroupid, ret); } int btrfs_subvol_find_subtree_qgroup(int fd, uint64_t subvol_id, uint64_t *ret) { uint64_t level, lowest = UINT64_MAX, lowest_qgroupid = 0; _cleanup_free_ uint64_t *qgroups = NULL; int r, n; assert(fd >= 0); assert(ret); /* This finds the "subtree" qgroup for a specific * subvolume. This only works for subvolumes that have been * prepared with btrfs_subvol_auto_qgroup_fd() with * insert_intermediary_qgroup=true (or equivalent). For others * it will return the leaf qgroup instead. The two cases may * be distinguished via the return value, which is 1 in case * an appropriate "subtree" qgroup was found, and 0 * otherwise. */ if (subvol_id == 0) { r = btrfs_subvol_get_id_fd(fd, &subvol_id); if (r < 0) return r; } r = btrfs_qgroupid_split(subvol_id, &level, NULL); if (r < 0) return r; if (level != 0) /* Input must be a leaf qgroup */ return -EINVAL; n = btrfs_qgroup_find_parents(fd, subvol_id, &qgroups); if (n < 0) return n; for (int i = 0; i < n; i++) { uint64_t id; r = btrfs_qgroupid_split(qgroups[i], &level, &id); if (r < 0) return r; if (id != subvol_id) continue; if (lowest == UINT64_MAX || level < lowest) { lowest_qgroupid = qgroups[i]; lowest = level; } } if (lowest == UINT64_MAX) { /* No suitable higher-level qgroup found, let's return * the leaf qgroup instead, and indicate that with the * return value. */ *ret = subvol_id; return 0; } *ret = lowest_qgroupid; return 1; } int btrfs_subvol_get_subtree_quota_fd(int fd, uint64_t subvol_id, BtrfsQuotaInfo *ret) { uint64_t qgroupid; int r; assert(fd >= 0); assert(ret); /* This determines the quota data of the qgroup with the * lowest level, that shares the id part with the specified * subvolume. This is useful for determining the quota data * for entire subvolume subtrees, as long as the subtrees have * been set up with btrfs_qgroup_subvol_auto_fd() or in a * compatible way */ r = btrfs_subvol_find_subtree_qgroup(fd, subvol_id, &qgroupid); if (r < 0) return r; return btrfs_qgroup_get_quota_fd(fd, qgroupid, ret); } int btrfs_subvol_get_subtree_quota(const char *path, uint64_t subvol_id, BtrfsQuotaInfo *ret) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_subvol_get_subtree_quota_fd(fd, subvol_id, ret); } int btrfs_defrag_fd(int fd) { int r; assert(fd >= 0); r = fd_verify_regular(fd); if (r < 0) return r; return RET_NERRNO(ioctl(fd, BTRFS_IOC_DEFRAG, NULL)); } int btrfs_defrag(const char *p) { _cleanup_close_ int fd = -EBADF; fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_defrag_fd(fd); } int btrfs_quota_enable_fd(int fd, bool b) { struct btrfs_ioctl_quota_ctl_args args = { .cmd = b ? BTRFS_QUOTA_CTL_ENABLE : BTRFS_QUOTA_CTL_DISABLE, }; int r; assert(fd >= 0); r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; return RET_NERRNO(ioctl(fd, BTRFS_IOC_QUOTA_CTL, &args)); } int btrfs_quota_enable(const char *path, bool b) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_quota_enable_fd(fd, b); } int btrfs_qgroup_set_limit_fd(int fd, uint64_t qgroupid, uint64_t referenced_max) { struct btrfs_ioctl_qgroup_limit_args args = { .lim.max_rfer = referenced_max, .lim.flags = BTRFS_QGROUP_LIMIT_MAX_RFER, }; int r; assert(fd >= 0); if (qgroupid == 0) { r = btrfs_subvol_get_id_fd(fd, &qgroupid); if (r < 0) return r; } else { r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; } args.qgroupid = qgroupid; for (unsigned c = 0;; c++) { if (ioctl(fd, BTRFS_IOC_QGROUP_LIMIT, &args) < 0) { if (errno == EBUSY && c < 10) { (void) btrfs_quota_scan_wait(fd); continue; } return -errno; } break; } return 0; } int btrfs_qgroup_set_limit(const char *path, uint64_t qgroupid, uint64_t referenced_max) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_qgroup_set_limit_fd(fd, qgroupid, referenced_max); } int btrfs_subvol_set_subtree_quota_limit_fd(int fd, uint64_t subvol_id, uint64_t referenced_max) { uint64_t qgroupid; int r; assert(fd >= 0); r = btrfs_subvol_find_subtree_qgroup(fd, subvol_id, &qgroupid); if (r < 0) return r; return btrfs_qgroup_set_limit_fd(fd, qgroupid, referenced_max); } int btrfs_subvol_set_subtree_quota_limit(const char *path, uint64_t subvol_id, uint64_t referenced_max) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return btrfs_subvol_set_subtree_quota_limit_fd(fd, subvol_id, referenced_max); } int btrfs_qgroupid_make(uint64_t level, uint64_t id, uint64_t *ret) { assert(ret); if (level >= (UINT64_C(1) << (64 - BTRFS_QGROUP_LEVEL_SHIFT))) return -EINVAL; if (id >= (UINT64_C(1) << BTRFS_QGROUP_LEVEL_SHIFT)) return -EINVAL; *ret = (level << BTRFS_QGROUP_LEVEL_SHIFT) | id; return 0; } int btrfs_qgroupid_split(uint64_t qgroupid, uint64_t *level, uint64_t *id) { assert(level || id); if (level) *level = qgroupid >> BTRFS_QGROUP_LEVEL_SHIFT; if (id) *id = qgroupid & ((UINT64_C(1) << BTRFS_QGROUP_LEVEL_SHIFT) - 1); return 0; } static int qgroup_create_or_destroy(int fd, bool b, uint64_t qgroupid) { struct btrfs_ioctl_qgroup_create_args args = { .create = b, .qgroupid = qgroupid, }; int r; r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; for (unsigned c = 0;; c++) { if (ioctl(fd, BTRFS_IOC_QGROUP_CREATE, &args) < 0) { /* On old kernels if quota is not enabled, we get EINVAL. On newer kernels we get * ENOTCONN. Let's always convert this to ENOTCONN to make this recognizable * everywhere the same way. */ if (IN_SET(errno, EINVAL, ENOTCONN)) return -ENOTCONN; if (errno == EBUSY && c < 10) { (void) btrfs_quota_scan_wait(fd); continue; } return -errno; } break; } return 0; } int btrfs_qgroup_create(int fd, uint64_t qgroupid) { return qgroup_create_or_destroy(fd, true, qgroupid); } int btrfs_qgroup_destroy(int fd, uint64_t qgroupid) { return qgroup_create_or_destroy(fd, false, qgroupid); } int btrfs_qgroup_destroy_recursive(int fd, uint64_t qgroupid) { _cleanup_free_ uint64_t *qgroups = NULL; uint64_t subvol_id; int n, r; /* Destroys the specified qgroup, but unassigns it from all * its parents first. Also, it recursively destroys all * qgroups it is assigned to that have the same id part of the * qgroupid as the specified group. */ r = btrfs_qgroupid_split(qgroupid, NULL, &subvol_id); if (r < 0) return r; n = btrfs_qgroup_find_parents(fd, qgroupid, &qgroups); if (n < 0) return n; for (int i = 0; i < n; i++) { uint64_t id; r = btrfs_qgroupid_split(qgroups[i], NULL, &id); if (r < 0) return r; r = btrfs_qgroup_unassign(fd, qgroupid, qgroups[i]); if (r < 0) return r; if (id != subvol_id) continue; /* The parent qgroupid shares the same id part with * us? If so, destroy it too. */ (void) btrfs_qgroup_destroy_recursive(fd, qgroups[i]); } return btrfs_qgroup_destroy(fd, qgroupid); } int btrfs_quota_scan_start(int fd) { struct btrfs_ioctl_quota_rescan_args args = {}; assert(fd >= 0); return RET_NERRNO(ioctl(fd, BTRFS_IOC_QUOTA_RESCAN, &args)); } int btrfs_quota_scan_wait(int fd) { assert(fd >= 0); return RET_NERRNO(ioctl(fd, BTRFS_IOC_QUOTA_RESCAN_WAIT)); } int btrfs_quota_scan_ongoing(int fd) { struct btrfs_ioctl_quota_rescan_args args = {}; assert(fd >= 0); if (ioctl(fd, BTRFS_IOC_QUOTA_RESCAN_STATUS, &args) < 0) return -errno; return !!args.flags; } static int qgroup_assign_or_unassign(int fd, bool b, uint64_t child, uint64_t parent) { struct btrfs_ioctl_qgroup_assign_args args = { .assign = b, .src = child, .dst = parent, }; int r; r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; for (unsigned c = 0;; c++) { r = ioctl(fd, BTRFS_IOC_QGROUP_ASSIGN, &args); if (r < 0) { if (errno == EBUSY && c < 10) { (void) btrfs_quota_scan_wait(fd); continue; } return -errno; } if (r == 0) return 0; /* If the return value is > 0, we need to request a rescan */ (void) btrfs_quota_scan_start(fd); return 1; } } int btrfs_qgroup_assign(int fd, uint64_t child, uint64_t parent) { return qgroup_assign_or_unassign(fd, true, child, parent); } int btrfs_qgroup_unassign(int fd, uint64_t child, uint64_t parent) { return qgroup_assign_or_unassign(fd, false, child, parent); } static int subvol_remove_children(int fd, const char *subvolume, uint64_t subvol_id, BtrfsRemoveFlags flags) { struct btrfs_ioctl_search_args args = { .key.tree_id = BTRFS_ROOT_TREE_OBJECTID, .key.min_objectid = BTRFS_FIRST_FREE_OBJECTID, .key.max_objectid = BTRFS_LAST_FREE_OBJECTID, .key.min_type = BTRFS_ROOT_BACKREF_KEY, .key.max_type = BTRFS_ROOT_BACKREF_KEY, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; struct btrfs_ioctl_vol_args vol_args = {}; _cleanup_close_ int subvol_fd = -EBADF; struct stat st; bool made_writable = false; int r; assert(fd >= 0); assert(subvolume); if (fstat(fd, &st) < 0) return -errno; if (!S_ISDIR(st.st_mode)) return -EINVAL; subvol_fd = openat(fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (subvol_fd < 0) return -errno; /* Let's check if this is actually a subvolume. Note that this is mostly redundant, as BTRFS_IOC_SNAP_DESTROY * would fail anyway if it is not. However, it's a good thing to check this ahead of time so that we can return * ENOTTY unconditionally in this case. This is different from the ioctl() which will return EPERM/EACCES if we * don't have the privileges to remove subvolumes, regardless if the specified directory is actually a * subvolume or not. In order to make it easy for callers to cover the "this is not a btrfs subvolume" case * let's prefer ENOTTY over EPERM/EACCES though. */ r = btrfs_is_subvol_fd(subvol_fd); if (r < 0) return r; if (r == 0) /* Not a btrfs subvolume */ return -ENOTTY; if (subvol_id == 0) { r = btrfs_subvol_get_id_fd(subvol_fd, &subvol_id); if (r < 0) return r; } /* First, try to remove the subvolume. If it happens to be * already empty, this will just work. */ strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1); if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) >= 0) { (void) btrfs_qgroup_destroy_recursive(fd, subvol_id); /* for the leaf subvolumes, the qgroup id is identical to the subvol id */ return 0; } if (!(flags & BTRFS_REMOVE_RECURSIVE) || errno != ENOTEMPTY) return -errno; /* OK, the subvolume is not empty, let's look for child * subvolumes, and remove them, first */ args.key.min_offset = args.key.max_offset = subvol_id; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) return -errno; if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { _cleanup_free_ char *p = NULL; btrfs_ioctl_search_args_set(&args, &sh); if (sh.type != BTRFS_ROOT_BACKREF_KEY) continue; if (sh.offset != subvol_id) continue; const struct btrfs_root_ref *ref = body; p = memdup_suffix0((char*) ref + sizeof(struct btrfs_root_ref), le64toh(ref->name_len)); if (!p) return -ENOMEM; struct btrfs_ioctl_ino_lookup_args ino_args = { .treeid = subvol_id, .objectid = htole64(ref->dirid), }; if (ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0) return -errno; if (!made_writable) { r = btrfs_subvol_set_read_only_fd(subvol_fd, false); if (r < 0) return r; made_writable = true; } if (isempty(ino_args.name)) /* Subvolume is in the top-level * directory of the subvolume. */ r = subvol_remove_children(subvol_fd, p, sh.objectid, flags); else { _cleanup_close_ int child_fd = -EBADF; /* Subvolume is somewhere further down, * hence we need to open the * containing directory first */ child_fd = openat(subvol_fd, ino_args.name, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (child_fd < 0) return -errno; r = subvol_remove_children(child_fd, p, sh.objectid, flags); } if (r < 0) return r; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } /* OK, the child subvolumes should all be gone now, let's try * again to remove the subvolume */ if (ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &vol_args) < 0) return -errno; (void) btrfs_qgroup_destroy_recursive(fd, subvol_id); return 0; } int btrfs_subvol_remove_at(int dir_fd, const char *path, BtrfsRemoveFlags flags) { _cleanup_free_ char *subvolume = NULL; _cleanup_close_ int fd = -EBADF; int r; assert(path); fd = chase_and_openat(dir_fd, path, CHASE_PARENT|CHASE_EXTRACT_FILENAME, O_CLOEXEC, &subvolume); if (fd < 0) return fd; r = btrfs_validate_subvolume_name(subvolume); if (r < 0) return r; return subvol_remove_children(fd, subvolume, 0, flags); } int btrfs_qgroup_copy_limits(int fd, uint64_t old_qgroupid, uint64_t new_qgroupid) { struct btrfs_ioctl_search_args args = { /* Tree of quota items */ .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID, /* The object ID is always 0 */ .key.min_objectid = 0, .key.max_objectid = 0, /* Look precisely for the quota items */ .key.min_type = BTRFS_QGROUP_LIMIT_KEY, .key.max_type = BTRFS_QGROUP_LIMIT_KEY, /* For our qgroup */ .key.min_offset = old_qgroupid, .key.max_offset = old_qgroupid, /* No restrictions on the other components */ .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; int r; r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) { if (errno == ENOENT) /* quota tree missing: quota is not enabled, hence nothing to copy */ break; return -errno; } if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { struct btrfs_ioctl_qgroup_limit_args qargs; unsigned c; /* Make sure we start the next search at least from this entry */ btrfs_ioctl_search_args_set(&args, &sh); if (sh.objectid != 0) continue; if (sh.type != BTRFS_QGROUP_LIMIT_KEY) continue; if (sh.offset != old_qgroupid) continue; /* We found the entry, now copy things over. */ const struct btrfs_qgroup_limit_item *qli = body; qargs = (struct btrfs_ioctl_qgroup_limit_args) { .qgroupid = new_qgroupid, .lim.max_rfer = le64toh(qli->max_rfer), .lim.max_excl = le64toh(qli->max_excl), .lim.rsv_rfer = le64toh(qli->rsv_rfer), .lim.rsv_excl = le64toh(qli->rsv_excl), .lim.flags = le64toh(qli->flags) & (BTRFS_QGROUP_LIMIT_MAX_RFER| BTRFS_QGROUP_LIMIT_MAX_EXCL| BTRFS_QGROUP_LIMIT_RSV_RFER| BTRFS_QGROUP_LIMIT_RSV_EXCL), }; for (c = 0;; c++) { if (ioctl(fd, BTRFS_IOC_QGROUP_LIMIT, &qargs) < 0) { if (errno == EBUSY && c < 10) { (void) btrfs_quota_scan_wait(fd); continue; } return -errno; } break; } return 1; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } return 0; } static int copy_quota_hierarchy(int fd, uint64_t old_subvol_id, uint64_t new_subvol_id) { _cleanup_free_ uint64_t *old_qgroups = NULL, *old_parent_qgroups = NULL; bool copy_from_parent = false, insert_intermediary_qgroup = false; int n_old_qgroups, n_old_parent_qgroups, r; uint64_t old_parent_id; assert(fd >= 0); /* Copies a reduced form of quota information from the old to * the new subvolume. */ n_old_qgroups = btrfs_qgroup_find_parents(fd, old_subvol_id, &old_qgroups); if (n_old_qgroups <= 0) /* Nothing to copy */ return n_old_qgroups; assert(old_qgroups); /* Coverity gets confused by the macro iterator allocating this, add a hint */ r = btrfs_subvol_get_parent(fd, old_subvol_id, &old_parent_id); if (r == -ENXIO) /* We have no parent, hence nothing to copy. */ n_old_parent_qgroups = 0; else if (r < 0) return r; else { n_old_parent_qgroups = btrfs_qgroup_find_parents(fd, old_parent_id, &old_parent_qgroups); if (n_old_parent_qgroups < 0) return n_old_parent_qgroups; } for (int i = 0; i < n_old_qgroups; i++) { uint64_t id; r = btrfs_qgroupid_split(old_qgroups[i], NULL, &id); if (r < 0) return r; if (id == old_subvol_id) { /* The old subvolume was member of a qgroup * that had the same id, but a different level * as it self. Let's set up something similar * in the destination. */ insert_intermediary_qgroup = true; break; } for (int j = 0; j < n_old_parent_qgroups; j++) if (old_parent_qgroups[j] == old_qgroups[i]) /* The old subvolume shared a common * parent qgroup with its parent * subvolume. Let's set up something * similar in the destination. */ copy_from_parent = true; } if (!insert_intermediary_qgroup && !copy_from_parent) return 0; return btrfs_subvol_auto_qgroup_fd(fd, new_subvol_id, insert_intermediary_qgroup); } static int copy_subtree_quota_limits(int fd, uint64_t old_subvol, uint64_t new_subvol) { uint64_t old_subtree_qgroup, new_subtree_qgroup; bool changed; int r; /* First copy the leaf limits */ r = btrfs_qgroup_copy_limits(fd, old_subvol, new_subvol); if (r < 0) return r; changed = r > 0; /* Then, try to copy the subtree limits, if there are any. */ r = btrfs_subvol_find_subtree_qgroup(fd, old_subvol, &old_subtree_qgroup); if (r < 0) return r; if (r == 0) return changed; r = btrfs_subvol_find_subtree_qgroup(fd, new_subvol, &new_subtree_qgroup); if (r < 0) return r; if (r == 0) return changed; r = btrfs_qgroup_copy_limits(fd, old_subtree_qgroup, new_subtree_qgroup); if (r != 0) return r; return changed; } static int subvol_snapshot_children( int old_fd, int new_fd, const char *subvolume, uint64_t old_subvol_id, BtrfsSnapshotFlags flags) { struct btrfs_ioctl_search_args args = { .key.tree_id = BTRFS_ROOT_TREE_OBJECTID, .key.min_objectid = BTRFS_FIRST_FREE_OBJECTID, .key.max_objectid = BTRFS_LAST_FREE_OBJECTID, .key.min_type = BTRFS_ROOT_BACKREF_KEY, .key.max_type = BTRFS_ROOT_BACKREF_KEY, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; struct btrfs_ioctl_vol_args_v2 vol_args = { .flags = flags & BTRFS_SNAPSHOT_READ_ONLY ? BTRFS_SUBVOL_RDONLY : 0, .fd = old_fd, }; _cleanup_close_ int subvolume_fd = -EBADF; uint64_t new_subvol_id; int r; assert(old_fd >= 0); assert(new_fd >= 0); assert(subvolume); strncpy(vol_args.name, subvolume, sizeof(vol_args.name)-1); if (ioctl(new_fd, BTRFS_IOC_SNAP_CREATE_V2, &vol_args) < 0) return -errno; if (FLAGS_SET(flags, BTRFS_SNAPSHOT_LOCK_BSD)) { subvolume_fd = xopenat_lock(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW, LOCK_BSD, LOCK_EX); if (subvolume_fd < 0) return subvolume_fd; r = btrfs_is_subvol_fd(subvolume_fd); if (r < 0) return r; if (r == 0) return -EEXIST; } if (!(flags & BTRFS_SNAPSHOT_RECURSIVE) && !(flags & BTRFS_SNAPSHOT_QUOTA)) return flags & BTRFS_SNAPSHOT_LOCK_BSD ? TAKE_FD(subvolume_fd) : 0; if (old_subvol_id == 0) { r = btrfs_subvol_get_id_fd(old_fd, &old_subvol_id); if (r < 0) return r; } r = btrfs_subvol_get_id(new_fd, vol_args.name, &new_subvol_id); if (r < 0) return r; if (flags & BTRFS_SNAPSHOT_QUOTA) (void) copy_quota_hierarchy(new_fd, old_subvol_id, new_subvol_id); if (!(flags & BTRFS_SNAPSHOT_RECURSIVE)) { if (flags & BTRFS_SNAPSHOT_QUOTA) (void) copy_subtree_quota_limits(new_fd, old_subvol_id, new_subvol_id); return flags & BTRFS_SNAPSHOT_LOCK_BSD ? TAKE_FD(subvolume_fd) : 0; } args.key.min_offset = args.key.max_offset = old_subvol_id; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; args.key.nr_items = 256; if (ioctl(old_fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) return -errno; if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { _cleanup_free_ char *p = NULL, *c = NULL, *np = NULL; _cleanup_close_ int old_child_fd = -EBADF, new_child_fd = -EBADF; btrfs_ioctl_search_args_set(&args, &sh); if (sh.type != BTRFS_ROOT_BACKREF_KEY) continue; /* Avoid finding the source subvolume a second time */ if (sh.offset != old_subvol_id) continue; /* Avoid running into loops if the new subvolume is below the old one. */ if (sh.objectid == new_subvol_id) continue; const struct btrfs_root_ref *ref = body; p = memdup_suffix0((char*) ref + sizeof(struct btrfs_root_ref), le64toh(ref->name_len)); if (!p) return -ENOMEM; struct btrfs_ioctl_ino_lookup_args ino_args = { .treeid = old_subvol_id, .objectid = htole64(ref->dirid), }; if (ioctl(old_fd, BTRFS_IOC_INO_LOOKUP, &ino_args) < 0) return -errno; c = path_join(ino_args.name, p); if (!c) return -ENOMEM; old_child_fd = openat(old_fd, c, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (old_child_fd < 0) return -errno; np = path_join(subvolume, ino_args.name); if (!np) return -ENOMEM; new_child_fd = openat(new_fd, np, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (new_child_fd < 0) return -errno; if (flags & BTRFS_SNAPSHOT_READ_ONLY) { /* If the snapshot is read-only we need to mark it writable temporarily, to * put the subsnapshot into place. */ if (subvolume_fd < 0) { subvolume_fd = openat(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW); if (subvolume_fd < 0) return -errno; } r = btrfs_subvol_set_read_only_fd(subvolume_fd, false); if (r < 0) return r; } /* When btrfs clones the subvolumes, child subvolumes appear as empty * directories. Remove them, so that we can create a new snapshot in their place */ if (unlinkat(new_child_fd, p, AT_REMOVEDIR) < 0) { int k = -errno; if (flags & BTRFS_SNAPSHOT_READ_ONLY) (void) btrfs_subvol_set_read_only_fd(subvolume_fd, true); return k; } r = subvol_snapshot_children(old_child_fd, new_child_fd, p, sh.objectid, flags & ~(BTRFS_SNAPSHOT_FALLBACK_COPY|BTRFS_SNAPSHOT_LOCK_BSD)); /* Restore the readonly flag */ if (flags & BTRFS_SNAPSHOT_READ_ONLY) { int k; k = btrfs_subvol_set_read_only_fd(subvolume_fd, true); if (r >= 0 && k < 0) return k; } if (r < 0) return r; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } if (flags & BTRFS_SNAPSHOT_QUOTA) (void) copy_subtree_quota_limits(new_fd, old_subvol_id, new_subvol_id); return flags & BTRFS_SNAPSHOT_LOCK_BSD ? TAKE_FD(subvolume_fd) : 0; } int btrfs_subvol_snapshot_at_full( int dir_fdf, const char *from, int dir_fdt, const char *to, BtrfsSnapshotFlags flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata) { _cleanup_free_ char *subvolume = NULL; _cleanup_close_ int old_fd = -EBADF, new_fd = -EBADF, subvolume_fd = -EBADF; int r; assert(dir_fdf >= 0 || dir_fdf == AT_FDCWD); assert(dir_fdt >= 0 || dir_fdt == AT_FDCWD); assert(to); old_fd = xopenat(dir_fdf, from, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); if (old_fd < 0) return old_fd; new_fd = chase_and_openat(dir_fdt, to, CHASE_PARENT|CHASE_EXTRACT_FILENAME, O_CLOEXEC, &subvolume); if (new_fd < 0) return new_fd; r = btrfs_validate_subvolume_name(subvolume); if (r < 0) return r; r = btrfs_is_subvol_at(dir_fdf, from); if (r < 0) return r; if (r == 0) { bool plain_directory = false; /* If the source isn't a proper subvolume, fail unless fallback is requested */ if (!(flags & BTRFS_SNAPSHOT_FALLBACK_COPY)) return -EISDIR; r = btrfs_subvol_make(new_fd, subvolume); if (r < 0) { if (ERRNO_IS_NOT_SUPPORTED(r) && (flags & BTRFS_SNAPSHOT_FALLBACK_DIRECTORY)) { /* If the destination doesn't support subvolumes, then use a plain directory, if that's requested. */ if (mkdirat(new_fd, subvolume, 0755) < 0) return -errno; plain_directory = true; } else return r; } if (FLAGS_SET(flags, BTRFS_SNAPSHOT_LOCK_BSD)) { subvolume_fd = xopenat_lock(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW, LOCK_BSD, LOCK_EX); if (subvolume_fd < 0) return subvolume_fd; if (!plain_directory) { r = btrfs_is_subvol_fd(subvolume_fd); if (r < 0) return r; if (r == 0) return -EEXIST; } } r = copy_directory_at_full( dir_fdf, from, new_fd, subvolume, COPY_MERGE_EMPTY| COPY_REFLINK| COPY_SAME_MOUNT| COPY_HARDLINKS| COPY_ALL_XATTRS| (FLAGS_SET(flags, BTRFS_SNAPSHOT_SIGINT) ? COPY_SIGINT : 0)| (FLAGS_SET(flags, BTRFS_SNAPSHOT_SIGTERM) ? COPY_SIGTERM : 0), progress_path, progress_bytes, userdata); if (r < 0) goto fallback_fail; if (flags & BTRFS_SNAPSHOT_READ_ONLY) { if (plain_directory) { /* Plain directories have no recursive read-only flag, but something pretty close to * it: the IMMUTABLE bit. Let's use this here, if this is requested. */ if (flags & BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE) (void) chattr_at(new_fd, subvolume, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL, NULL); } else { r = btrfs_subvol_set_read_only_at(new_fd, subvolume, true); if (r < 0) goto fallback_fail; } } return flags & BTRFS_SNAPSHOT_LOCK_BSD ? TAKE_FD(subvolume_fd) : 0; fallback_fail: (void) rm_rf_at(new_fd, subvolume, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME); return r; } return subvol_snapshot_children(old_fd, new_fd, subvolume, 0, flags); } int btrfs_qgroup_find_parents(int fd, uint64_t qgroupid, uint64_t **ret) { struct btrfs_ioctl_search_args args = { /* Tree of quota items */ .key.tree_id = BTRFS_QUOTA_TREE_OBJECTID, /* Look precisely for the quota relation items */ .key.min_type = BTRFS_QGROUP_RELATION_KEY, .key.max_type = BTRFS_QGROUP_RELATION_KEY, /* No restrictions on the other components */ .key.min_offset = 0, .key.max_offset = UINT64_MAX, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; _cleanup_free_ uint64_t *items = NULL; size_t n_items = 0; int r; assert(fd >= 0); assert(ret); if (qgroupid == 0) { r = btrfs_subvol_get_id_fd(fd, &qgroupid); if (r < 0) return r; } else { r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; } args.key.min_objectid = args.key.max_objectid = qgroupid; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; _unused_ const void *body; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) { if (errno == ENOENT) /* quota tree missing: quota is disabled */ break; return -errno; } if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { /* Make sure we start the next search at least from this entry */ btrfs_ioctl_search_args_set(&args, &sh); if (sh.type != BTRFS_QGROUP_RELATION_KEY) continue; if (sh.offset < sh.objectid) continue; if (sh.objectid != qgroupid) continue; if (!GREEDY_REALLOC(items, n_items+1)) return -ENOMEM; items[n_items++] = sh.offset; } /* Increase search key by one, to read the next item, if we can. */ if (!btrfs_ioctl_search_args_inc(&args)) break; } if (n_items <= 0) { *ret = NULL; return 0; } *ret = TAKE_PTR(items); return (int) n_items; } int btrfs_subvol_auto_qgroup_fd(int fd, uint64_t subvol_id, bool insert_intermediary_qgroup) { _cleanup_free_ uint64_t *qgroups = NULL; _cleanup_close_ int real_fd = -EBADF; uint64_t parent_subvol; bool changed = false; int n = 0, r; assert(fd >= 0); /* * Sets up the specified subvolume's qgroup automatically in * one of two ways: * * If insert_intermediary_qgroup is false, the subvolume's * leaf qgroup will be assigned to the same parent qgroups as * the subvolume's parent subvolume. * * If insert_intermediary_qgroup is true a new intermediary * higher-level qgroup is created, with a higher level number, * but reusing the id of the subvolume. The level number is * picked as one smaller than the lowest level qgroup the * parent subvolume is a member of. If the parent subvolume's * leaf qgroup is assigned to no higher-level qgroup a new * qgroup of level 255 is created instead. Either way, the new * qgroup is then assigned to the parent's higher-level * qgroup, and the subvolume itself is assigned to it. * * If the subvolume is already assigned to a higher level * qgroup, no operation is executed. * * Effectively this means: regardless if * insert_intermediary_qgroup is true or not, after this * function is invoked the subvolume will be accounted within * the same qgroups as the parent. However, if it is true, it * will also get its own higher-level qgroup, which may in * turn be used by subvolumes created beneath this subvolume * later on. * * This hence defines a simple default qgroup setup for * subvolumes, as long as this function is invoked on each * created subvolume: each subvolume is always accounting * together with its immediate parents. Optionally, if * insert_intermediary_qgroup is true, it will also get a * qgroup that then includes all its own child subvolumes. */ /* Turn this into a proper fd, if it is currently O_PATH */ fd = fd_reopen_condition(fd, O_RDONLY|O_CLOEXEC, O_PATH, &real_fd); if (fd < 0) return fd; if (subvol_id == 0) { r = btrfs_is_subvol_fd(fd); if (r < 0) return r; if (!r) return -ENOTTY; r = btrfs_subvol_get_id_fd(fd, &subvol_id); if (r < 0) return r; } n = btrfs_qgroup_find_parents(fd, subvol_id, &qgroups); if (n < 0) return n; if (n > 0) /* already parent qgroups set up, let's bail */ return 0; qgroups = mfree(qgroups); r = btrfs_subvol_get_parent(fd, subvol_id, &parent_subvol); if (r == -ENXIO) /* No parent, hence no qgroup memberships */ n = 0; else if (r < 0) return r; else { n = btrfs_qgroup_find_parents(fd, parent_subvol, &qgroups); if (n < 0) return n; } if (insert_intermediary_qgroup) { uint64_t lowest = 256, new_qgroupid; bool created = false; /* Determine the lowest qgroup that the parent * subvolume is assigned to. */ for (int i = 0; i < n; i++) { uint64_t level; r = btrfs_qgroupid_split(qgroups[i], &level, NULL); if (r < 0) return r; if (level < lowest) lowest = level; } if (lowest <= 1) /* There are no levels left we could use insert an intermediary qgroup at */ return -EBUSY; r = btrfs_qgroupid_make(lowest - 1, subvol_id, &new_qgroupid); if (r < 0) return r; /* Create the new intermediary group, unless it already exists */ r = btrfs_qgroup_create(fd, new_qgroupid); if (r < 0 && r != -EEXIST) return r; if (r >= 0) changed = created = true; for (int i = 0; i < n; i++) { r = btrfs_qgroup_assign(fd, new_qgroupid, qgroups[i]); if (r < 0 && r != -EEXIST) { if (created) (void) btrfs_qgroup_destroy_recursive(fd, new_qgroupid); return r; } if (r >= 0) changed = true; } r = btrfs_qgroup_assign(fd, subvol_id, new_qgroupid); if (r < 0 && r != -EEXIST) { if (created) (void) btrfs_qgroup_destroy_recursive(fd, new_qgroupid); return r; } if (r >= 0) changed = true; } else { int i; /* Assign our subvolume to all the same qgroups as the parent */ for (i = 0; i < n; i++) { r = btrfs_qgroup_assign(fd, subvol_id, qgroups[i]); if (r < 0 && r != -EEXIST) return r; if (r >= 0) changed = true; } } return changed; } int btrfs_subvol_auto_qgroup(const char *path, uint64_t subvol_id, bool create_intermediary_qgroup) { _cleanup_close_ int fd = -EBADF; fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); if (fd < 0) return -errno; return btrfs_subvol_auto_qgroup_fd(fd, subvol_id, create_intermediary_qgroup); } int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret) { struct btrfs_ioctl_search_args args = { /* Tree of tree roots */ .key.tree_id = BTRFS_ROOT_TREE_OBJECTID, /* Look precisely for the subvolume items */ .key.min_type = BTRFS_ROOT_BACKREF_KEY, .key.max_type = BTRFS_ROOT_BACKREF_KEY, /* No restrictions on the other components */ .key.min_offset = 0, .key.max_offset = UINT64_MAX, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; int r; assert(fd >= 0); assert(ret); if (subvol_id == 0) { r = btrfs_subvol_get_id_fd(fd, &subvol_id); if (r < 0) return r; } else { r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; } args.key.min_objectid = args.key.max_objectid = subvol_id; while (btrfs_ioctl_search_args_compare(&args) <= 0) { struct btrfs_ioctl_search_header sh; _unused_ const void *body = NULL; args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) return negative_errno(); if (args.key.nr_items <= 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, args) { if (sh.type != BTRFS_ROOT_BACKREF_KEY) continue; if (sh.objectid != subvol_id) continue; *ret = sh.offset; return 0; } } return -ENXIO; } int btrfs_forget_device(const char *path) { _cleanup_close_ int control_fd = -EBADF; struct btrfs_ioctl_vol_args args = {}; assert(path); if (strlen(path) > BTRFS_PATH_NAME_MAX) return -E2BIG; strcpy(args.name, path); control_fd = open("/dev/btrfs-control", O_RDWR|O_CLOEXEC); if (control_fd < 0) return -errno; return RET_NERRNO(ioctl(control_fd, BTRFS_IOC_FORGET_DEV, &args)); } typedef struct BtrfsStripe { uint64_t devid; uint64_t offset; } BtrfsStripe; typedef struct BtrfsChunk { uint64_t offset; uint64_t length; uint64_t type; BtrfsStripe *stripes; uint16_t n_stripes; uint64_t stripe_len; } BtrfsChunk; typedef struct BtrfsChunkTree { BtrfsChunk **chunks; size_t n_chunks; } BtrfsChunkTree; static BtrfsChunk* btrfs_chunk_free(BtrfsChunk *chunk) { if (!chunk) return NULL; free(chunk->stripes); return mfree(chunk); } DEFINE_TRIVIAL_CLEANUP_FUNC(BtrfsChunk*, btrfs_chunk_free); static void btrfs_chunk_tree_done(BtrfsChunkTree *tree) { assert(tree); FOREACH_ARRAY(i, tree->chunks, tree->n_chunks) btrfs_chunk_free(*i); free(tree->chunks); } static int btrfs_read_chunk_tree_fd(int fd, BtrfsChunkTree *ret) { struct btrfs_ioctl_search_args search_args = { .key.tree_id = BTRFS_CHUNK_TREE_OBJECTID, .key.min_type = BTRFS_CHUNK_ITEM_KEY, .key.max_type = BTRFS_CHUNK_ITEM_KEY, .key.min_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID, .key.max_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID, .key.min_offset = 0, .key.max_offset = UINT64_MAX, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; _cleanup_(btrfs_chunk_tree_done) BtrfsChunkTree tree = {}; assert(fd >= 0); assert(ret); while (btrfs_ioctl_search_args_compare(&search_args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; search_args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_args) < 0) return -errno; if (search_args.key.nr_items == 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, search_args) { _cleanup_(btrfs_chunk_freep) BtrfsChunk *chunk = NULL; btrfs_ioctl_search_args_set(&search_args, &sh); if (sh.objectid != BTRFS_FIRST_CHUNK_TREE_OBJECTID) continue; if (sh.type != BTRFS_CHUNK_ITEM_KEY) continue; chunk = new(BtrfsChunk, 1); if (!chunk) return -ENOMEM; const struct btrfs_chunk *item = body; *chunk = (BtrfsChunk) { .offset = sh.offset, .length = le64toh(item->length), .type = le64toh(item->type), .n_stripes = le16toh(item->num_stripes), .stripe_len = le64toh(item->stripe_len), }; chunk->stripes = new(BtrfsStripe, chunk->n_stripes); if (!chunk->stripes) return -ENOMEM; for (size_t j = 0; j < chunk->n_stripes; j++) { const struct btrfs_stripe *stripe = &item->stripe + j; chunk->stripes[j] = (BtrfsStripe) { .devid = le64toh(stripe->devid), .offset = le64toh(stripe->offset), }; } if (!GREEDY_REALLOC(tree.chunks, tree.n_chunks + 1)) return -ENOMEM; tree.chunks[tree.n_chunks++] = TAKE_PTR(chunk); } if (!btrfs_ioctl_search_args_inc(&search_args)) break; } *ret = TAKE_STRUCT(tree); return 0; } static BtrfsChunk* btrfs_find_chunk_from_logical_address(const BtrfsChunkTree *tree, uint64_t logical) { size_t min_index, max_index; assert(tree); assert(tree->chunks || tree->n_chunks == 0); if (tree->n_chunks == 0) return NULL; /* bisection */ min_index = 0; max_index = tree->n_chunks - 1; while (min_index <= max_index) { size_t mid = (min_index + max_index) / 2; if (logical < tree->chunks[mid]->offset) { if (mid < 1) return NULL; max_index = mid - 1; } else if (logical >= tree->chunks[mid]->offset + tree->chunks[mid]->length) min_index = mid + 1; else return tree->chunks[mid]; } return NULL; } static int btrfs_is_nocow_fd(int fd) { unsigned flags; int r; assert(fd >= 0); r = fd_is_fs_type(fd, BTRFS_SUPER_MAGIC); if (r < 0) return r; if (r == 0) return -ENOTTY; r = read_attr_fd(fd, &flags); if (r < 0) return r; return FLAGS_SET(flags, FS_NOCOW_FL) && !FLAGS_SET(flags, FS_COMPR_FL); } int btrfs_get_file_physical_offset_fd(int fd, uint64_t *ret) { struct btrfs_ioctl_search_args search_args = { .key.min_type = BTRFS_EXTENT_DATA_KEY, .key.max_type = BTRFS_EXTENT_DATA_KEY, .key.min_offset = 0, .key.max_offset = UINT64_MAX, .key.min_transid = 0, .key.max_transid = UINT64_MAX, }; _cleanup_(btrfs_chunk_tree_done) BtrfsChunkTree tree = {}; uint64_t subvol_id; struct stat st; int r; assert(fd >= 0); assert(ret); if (fstat(fd, &st) < 0) return -errno; r = stat_verify_regular(&st); if (r < 0) return r; r = btrfs_is_nocow_fd(fd); if (r < 0) return r; if (r == 0) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: CoW enabled"); r = btrfs_subvol_get_id_fd(fd, &subvol_id); if (r < 0) return r; r = btrfs_read_chunk_tree_fd(fd, &tree); if (r < 0) return r; search_args.key.tree_id = subvol_id; search_args.key.min_objectid = search_args.key.max_objectid = st.st_ino; while (btrfs_ioctl_search_args_compare(&search_args) <= 0) { struct btrfs_ioctl_search_header sh; const void *body; search_args.key.nr_items = 256; if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_args) < 0) return -errno; if (search_args.key.nr_items == 0) break; FOREACH_BTRFS_IOCTL_SEARCH_HEADER(sh, body, search_args) { uint64_t logical_offset; BtrfsChunk *chunk; btrfs_ioctl_search_args_set(&search_args, &sh); if (sh.type != BTRFS_EXTENT_DATA_KEY) continue; if (sh.objectid != st.st_ino) continue; const struct btrfs_file_extent_item *item = body; if (!IN_SET(item->type, BTRFS_FILE_EXTENT_REG, BTRFS_FILE_EXTENT_PREALLOC)) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: invalid type %" PRIu8, item->type); if (item->compression != 0 || item->encryption != 0 || item->other_encoding != 0) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: has incompatible property"); logical_offset = le64toh(item->disk_bytenr); if (logical_offset == 0) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: failed to get logical offset"); chunk = btrfs_find_chunk_from_logical_address(&tree, logical_offset); if (!chunk) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: no matching chunk found"); if ((chunk->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot get physical address for btrfs extent: unsupported profile"); uint64_t relative_chunk, relative_stripe, stripe_nr; uint16_t stripe_index; assert(logical_offset >= chunk->offset); assert(chunk->n_stripes > 0); assert(chunk->stripe_len > 0); relative_chunk = logical_offset - chunk->offset; stripe_nr = relative_chunk / chunk->stripe_len; relative_stripe = relative_chunk - stripe_nr * chunk->stripe_len; stripe_index = stripe_nr % chunk->n_stripes; *ret = chunk->stripes[stripe_index].offset + stripe_nr / chunk->n_stripes * chunk->stripe_len + relative_stripe; return 0; } if (!btrfs_ioctl_search_args_inc(&search_args)) break; } return -ENODATA; }