/* * Copyright (C) 2007 Oracle. All rights reserved. * Copyright (C) 2008 Morey Roof. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kerncompat.h" #include "kernel-lib/radix-tree.h" #include "kernel-shared/ctree.h" #include "kernel-shared/disk-io.h" #include "kernel-shared/transaction.h" #include "crypto/crc32c.h" #include "common/utils.h" #include "common/path-utils.h" #include "common/device-scan.h" #include "kernel-shared/volumes.h" #include "ioctl.h" #include "cmds/commands.h" #include "mkfs/common.h" static int rand_seed_initialized = 0; static unsigned short rand_seed[3]; struct btrfs_config bconf; int btrfs_make_root_dir(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid) { int ret; struct btrfs_inode_item inode_item; time_t now = time(NULL); memset(&inode_item, 0, sizeof(inode_item)); btrfs_set_stack_inode_generation(&inode_item, trans->transid); btrfs_set_stack_inode_size(&inode_item, 0); btrfs_set_stack_inode_nlink(&inode_item, 1); btrfs_set_stack_inode_nbytes(&inode_item, root->fs_info->nodesize); btrfs_set_stack_inode_mode(&inode_item, S_IFDIR | 0755); btrfs_set_stack_timespec_sec(&inode_item.atime, now); btrfs_set_stack_timespec_nsec(&inode_item.atime, 0); btrfs_set_stack_timespec_sec(&inode_item.ctime, now); btrfs_set_stack_timespec_nsec(&inode_item.ctime, 0); btrfs_set_stack_timespec_sec(&inode_item.mtime, now); btrfs_set_stack_timespec_nsec(&inode_item.mtime, 0); btrfs_set_stack_timespec_sec(&inode_item.otime, now); btrfs_set_stack_timespec_nsec(&inode_item.otime, 0); if (root->fs_info->tree_root == root) btrfs_set_super_root_dir(root->fs_info->super_copy, objectid); ret = btrfs_insert_inode(trans, root, objectid, &inode_item); if (ret) goto error; ret = btrfs_insert_inode_ref(trans, root, "..", 2, objectid, objectid, 0); if (ret) goto error; btrfs_set_root_dirid(&root->root_item, objectid); ret = 0; error: return ret; } /* * Find the mount point for a mounted device. * On success, returns 0 with mountpoint in *mp. * On failure, returns -errno (not mounted yields -EINVAL) * Is noisy on failures, expects to be given a mounted device. */ int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) { int ret; int fd = -1; ret = path_is_block_device(dev); if (ret <= 0) { if (!ret) { error("not a block device: %s", dev); ret = -EINVAL; } else { errno = -ret; error("cannot check %s: %m", dev); } goto out; } fd = open(dev, O_RDONLY); if (fd < 0) { ret = -errno; error("cannot open %s: %m", dev); goto out; } ret = check_mounted_where(fd, dev, mp, mp_size, NULL, SBREAD_DEFAULT); if (!ret) { ret = -EINVAL; } else { /* mounted, all good */ ret = 0; } out: if (fd != -1) close(fd); return ret; } /* * Given a pathname, return a filehandle to: * the original pathname or, * if the pathname is a mounted btrfs device, to its mountpoint. * * On error, return -1, errno should be set. */ int open_path_or_dev_mnt(const char *path, DIR **dirstream, int verbose) { char mp[PATH_MAX]; int ret; if (path_is_block_device(path)) { ret = get_btrfs_mount(path, mp, sizeof(mp)); if (ret < 0) { /* not a mounted btrfs dev */ error_on(verbose, "'%s' is not a mounted btrfs device", path); errno = EINVAL; return -1; } ret = open_file_or_dir(mp, dirstream); error_on(verbose && ret < 0, "can't access '%s': %m", path); } else { ret = btrfs_open_dir(path, dirstream, 1); } return ret; } /* * Do the following checks before calling open_file_or_dir(): * 1: path is in a btrfs filesystem * 2: path is a directory if dir_only is 1 */ int btrfs_open(const char *path, DIR **dirstream, int verbose, int dir_only) { struct statfs stfs; struct stat st; int ret; if (statfs(path, &stfs) != 0) { error_on(verbose, "cannot access '%s': %m", path); return -1; } if (stfs.f_type != BTRFS_SUPER_MAGIC) { error_on(verbose, "not a btrfs filesystem: %s", path); return -2; } if (stat(path, &st) != 0) { error_on(verbose, "cannot access '%s': %m", path); return -1; } if (dir_only && !S_ISDIR(st.st_mode)) { error_on(verbose, "not a directory: %s", path); return -3; } ret = open_file_or_dir(path, dirstream); if (ret < 0) { error_on(verbose, "cannot access '%s': %m", path); } return ret; } int btrfs_open_dir(const char *path, DIR **dirstream, int verbose) { return btrfs_open(path, dirstream, verbose, 1); } int btrfs_open_file_or_dir(const char *path, DIR **dirstream, int verbose) { return btrfs_open(path, dirstream, verbose, 0); } /* Checks if a file is used (directly or indirectly via a loop device) * by a device in fs_devices */ static int blk_file_in_dev_list(struct btrfs_fs_devices* fs_devices, const char* file) { int ret; struct btrfs_device *device; list_for_each_entry(device, &fs_devices->devices, dev_list) { if((ret = is_same_loop_file(device->name, file))) return ret; } return 0; } /* * returns 1 if the device was mounted, < 0 on error or 0 if everything * is safe to continue. */ int check_mounted(const char* file) { int fd; int ret; fd = open(file, O_RDONLY); if (fd < 0) { error("mount check: cannot open %s: %m", file); return -errno; } ret = check_mounted_where(fd, file, NULL, 0, NULL, SBREAD_DEFAULT); close(fd); return ret; } int check_mounted_where(int fd, const char *file, char *where, int size, struct btrfs_fs_devices **fs_dev_ret, unsigned sbflags) { int ret; u64 total_devs = 1; int is_btrfs; struct btrfs_fs_devices *fs_devices_mnt = NULL; FILE *f; struct mntent *mnt; /* scan the initial device */ ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt, &total_devs, BTRFS_SUPER_INFO_OFFSET, sbflags); is_btrfs = (ret >= 0); /* scan other devices */ if (is_btrfs && total_devs > 1) { ret = btrfs_scan_devices(0); if (ret) return ret; } /* iterate over the list of currently mounted filesystems */ if ((f = setmntent ("/proc/self/mounts", "r")) == NULL) return -errno; while ((mnt = getmntent (f)) != NULL) { if(is_btrfs) { if(strcmp(mnt->mnt_type, "btrfs") != 0) continue; ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname); } else { /* ignore entries in the mount table that are not associated with a file*/ if((ret = path_is_reg_or_block_device(mnt->mnt_fsname)) < 0) goto out_mntloop_err; else if(!ret) continue; ret = is_same_loop_file(file, mnt->mnt_fsname); } if(ret < 0) goto out_mntloop_err; else if(ret) break; } /* Did we find an entry in mnt table? */ if (mnt && size && where) { strncpy(where, mnt->mnt_dir, size); where[size-1] = 0; } if (fs_dev_ret) *fs_dev_ret = fs_devices_mnt; ret = (mnt != NULL); out_mntloop_err: endmntent (f); return ret; } struct pending_dir { struct list_head list; char name[PATH_MAX]; }; /* * Note: this function uses a static per-thread buffer. Do not call this * function more than 10 times within one argument list! */ const char *pretty_size_mode(u64 size, unsigned mode) { static __thread int ps_index = 0; static __thread char ps_array[10][32]; char *ret; ret = ps_array[ps_index]; ps_index++; ps_index %= 10; (void)pretty_size_snprintf(size, ret, 32, mode); return ret; } static const char* unit_suffix_binary[] = { "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"}; static const char* unit_suffix_decimal[] = { "B", "kB", "MB", "GB", "TB", "PB", "EB"}; int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode) { int num_divs; float fraction; u64 base = 0; int mult = 0; const char** suffix = NULL; u64 last_size; int negative; if (str_size == 0) return 0; negative = !!(unit_mode & UNITS_NEGATIVE); unit_mode &= ~UNITS_NEGATIVE; if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) { if (negative) snprintf(str, str_size, "%lld", size); else snprintf(str, str_size, "%llu", size); return 0; } if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_BINARY) { base = 1024; mult = 1024; suffix = unit_suffix_binary; } else if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_DECIMAL) { base = 1000; mult = 1000; suffix = unit_suffix_decimal; } /* Unknown mode */ if (!base) { fprintf(stderr, "INTERNAL ERROR: unknown unit base, mode %u\n", unit_mode); assert(0); return -1; } num_divs = 0; last_size = size; switch (unit_mode & UNITS_MODE_MASK) { case UNITS_TBYTES: base *= mult; num_divs++; /* fallthrough */ case UNITS_GBYTES: base *= mult; num_divs++; /* fallthrough */ case UNITS_MBYTES: base *= mult; num_divs++; /* fallthrough */ case UNITS_KBYTES: num_divs++; break; case UNITS_BYTES: base = 1; num_divs = 0; break; default: if (negative) { s64 ssize = (s64)size; s64 last_ssize = ssize; while ((ssize < 0 ? -ssize : ssize) >= mult) { last_ssize = ssize; ssize /= mult; num_divs++; } last_size = (u64)last_ssize; } else { while (size >= mult) { last_size = size; size /= mult; num_divs++; } } /* * If the value is smaller than base, we didn't do any * division, in that case, base should be 1, not original * base, or the unit will be wrong */ if (num_divs == 0) base = 1; } if (num_divs >= ARRAY_SIZE(unit_suffix_binary)) { str[0] = '\0'; printf("INTERNAL ERROR: unsupported unit suffix, index %d\n", num_divs); assert(0); return -1; } if (negative) { fraction = (float)(s64)last_size / base; } else { fraction = (float)last_size / base; } return snprintf(str, str_size, "%.2f%s", fraction, suffix[num_divs]); } /* * Checks to make sure that the label matches our requirements. * Returns: 0 if everything is safe and usable -1 if the label is too long */ static int check_label(const char *input) { int len = strlen(input); if (len > BTRFS_LABEL_SIZE - 1) { error("label %s is too long (max %d)", input, BTRFS_LABEL_SIZE - 1); return -1; } return 0; } static int set_label_unmounted(const char *dev, const char *label) { struct btrfs_trans_handle *trans; struct btrfs_root *root; int ret; ret = check_mounted(dev); if (ret < 0) { error("checking mount status of %s failed: %d", dev, ret); return -1; } if (ret > 0) { error("device %s is mounted, use mount point", dev); return -1; } /* Open the super_block at the default location * and as read-write. */ root = open_ctree(dev, 0, OPEN_CTREE_WRITES); if (!root) /* errors are printed by open_ctree() */ return -1; trans = btrfs_start_transaction(root, 1); BUG_ON(IS_ERR(trans)); __strncpy_null(root->fs_info->super_copy->label, label, BTRFS_LABEL_SIZE - 1); btrfs_commit_transaction(trans, root); /* Now we close it since we are done. */ close_ctree(root); return 0; } static int set_label_mounted(const char *mount_path, const char *labelp) { int fd; char label[BTRFS_LABEL_SIZE]; fd = open(mount_path, O_RDONLY | O_NOATIME); if (fd < 0) { error("unable to access %s: %m", mount_path); return -1; } memset(label, 0, sizeof(label)); __strncpy_null(label, labelp, BTRFS_LABEL_SIZE - 1); if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) { error("unable to set label of %s: %m", mount_path); close(fd); return -1; } close(fd); return 0; } int get_label_unmounted(const char *dev, char *label) { struct btrfs_root *root; int ret; ret = check_mounted(dev); if (ret < 0) { error("checking mount status of %s failed: %d", dev, ret); return -1; } /* Open the super_block at the default location * and as read-only. */ root = open_ctree(dev, 0, 0); if(!root) return -1; __strncpy_null(label, root->fs_info->super_copy->label, BTRFS_LABEL_SIZE - 1); /* Now we close it since we are done. */ close_ctree(root); return 0; } /* * If a partition is mounted, try to get the filesystem label via its * mounted path rather than device. Return the corresponding error * the user specified the device path. */ int get_label_mounted(const char *mount_path, char *labelp) { char label[BTRFS_LABEL_SIZE]; int fd; int ret; fd = open(mount_path, O_RDONLY | O_NOATIME); if (fd < 0) { error("unable to access %s: %m", mount_path); return -1; } memset(label, '\0', sizeof(label)); ret = ioctl(fd, BTRFS_IOC_GET_FSLABEL, label); if (ret < 0) { if (errno != ENOTTY) error("unable to get label of %s: %m", mount_path); ret = -errno; close(fd); return ret; } __strncpy_null(labelp, label, BTRFS_LABEL_SIZE - 1); close(fd); return 0; } int get_label(const char *btrfs_dev, char *label) { int ret; ret = path_is_reg_or_block_device(btrfs_dev); if (!ret) ret = get_label_mounted(btrfs_dev, label); else if (ret > 0) ret = get_label_unmounted(btrfs_dev, label); return ret; } int set_label(const char *btrfs_dev, const char *label) { int ret; if (check_label(label)) return -1; ret = path_is_reg_or_block_device(btrfs_dev); if (!ret) ret = set_label_mounted(btrfs_dev, label); else if (ret > 0) ret = set_label_unmounted(btrfs_dev, label); return ret; } /* * A not-so-good version fls64. No fascinating optimization since * no one except parse_size_from_string uses it */ static int fls64(u64 x) { int i; for (i = 0; i <64; i++) if (x << i & (1ULL << 63)) return 64 - i; return 64 - i; } u64 parse_size_from_string(const char *s) { char c; char *endptr; u64 mult = 1; u64 ret; if (!s) { error("size value is empty"); exit(1); } if (s[0] == '-') { error("size value '%s' is less equal than 0", s); exit(1); } ret = strtoull(s, &endptr, 10); if (endptr == s) { error("size value '%s' is invalid", s); exit(1); } if (endptr[0] && endptr[1]) { error("illegal suffix contains character '%c' in wrong position", endptr[1]); exit(1); } /* * strtoll returns LLONG_MAX when overflow, if this happens, * need to call strtoull to get the real size */ if (errno == ERANGE && ret == ULLONG_MAX) { error("size value '%s' is too large for u64", s); exit(1); } if (endptr[0]) { c = tolower(endptr[0]); switch (c) { case 'e': mult *= 1024; /* fallthrough */ case 'p': mult *= 1024; /* fallthrough */ case 't': mult *= 1024; /* fallthrough */ case 'g': mult *= 1024; /* fallthrough */ case 'm': mult *= 1024; /* fallthrough */ case 'k': mult *= 1024; /* fallthrough */ case 'b': break; default: error("unknown size descriptor '%c'", c); exit(1); } } /* Check whether ret * mult overflow */ if (fls64(ret) + fls64(mult) - 1 > 64) { error("size value '%s' is too large for u64", s); exit(1); } ret *= mult; return ret; } u64 parse_qgroupid(const char *p) { char *s = strchr(p, '/'); const char *ptr_src_end = p + strlen(p); char *ptr_parse_end = NULL; enum btrfs_util_error err; u64 level; u64 id; int fd; int ret = 0; if (p[0] == '/') goto path; /* Numeric format like '0/257' is the primary case */ if (!s) { id = strtoull(p, &ptr_parse_end, 10); if (ptr_parse_end != ptr_src_end) goto path; return id; } level = strtoull(p, &ptr_parse_end, 10); if (ptr_parse_end != s) goto path; id = strtoull(s + 1, &ptr_parse_end, 10); if (ptr_parse_end != ptr_src_end) goto path; return (level << BTRFS_QGROUP_LEVEL_SHIFT) | id; path: /* Path format like subv at 'my_subvol' is the fallback case */ err = btrfs_util_is_subvolume(p); if (err) goto err; fd = open(p, O_RDONLY); if (fd < 0) goto err; ret = lookup_path_rootid(fd, &id); if (ret) { errno = -ret; error("failed to lookup root id: %m"); } close(fd); if (ret < 0) goto err; return id; err: error("invalid qgroupid or subvolume path: %s", p); exit(-1); } enum btrfs_csum_type parse_csum_type(const char *s) { if (strcasecmp(s, "crc32c") == 0) { return BTRFS_CSUM_TYPE_CRC32; } else if (strcasecmp(s, "xxhash64") == 0 || strcasecmp(s, "xxhash") == 0) { return BTRFS_CSUM_TYPE_XXHASH; } else if (strcasecmp(s, "sha256") == 0) { return BTRFS_CSUM_TYPE_SHA256; } else if (strcasecmp(s, "blake2b") == 0 || strcasecmp(s, "blake2") == 0) { return BTRFS_CSUM_TYPE_BLAKE2; } else { error("unknown csum type %s", s); exit(1); } /* not reached */ return 0; } int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags) { int ret; struct stat st; int fd; ret = stat(fname, &st); if (ret < 0) { return -1; } if (S_ISDIR(st.st_mode)) { *dirstream = opendir(fname); if (!*dirstream) return -1; fd = dirfd(*dirstream); } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) { fd = open(fname, open_flags); } else { /* * we set this on purpose, in case the caller output * strerror(errno) as success */ errno = EINVAL; return -1; } if (fd < 0) { fd = -1; if (*dirstream) { closedir(*dirstream); *dirstream = NULL; } } return fd; } int open_file_or_dir(const char *fname, DIR **dirstream) { return open_file_or_dir3(fname, dirstream, O_RDWR); } void close_file_or_dir(int fd, DIR *dirstream) { int old_errno; old_errno = errno; if (dirstream) { closedir(dirstream); } else if (fd >= 0) { close(fd); } errno = old_errno; } int get_device_info(int fd, u64 devid, struct btrfs_ioctl_dev_info_args *di_args) { int ret; di_args->devid = devid; memset(&di_args->uuid, '\0', sizeof(di_args->uuid)); ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args); return ret < 0 ? -errno : 0; } int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret) { u64 count = 0; int ret; struct btrfs_ioctl_space_args *sargs; sargs = malloc(sizeof(struct btrfs_ioctl_space_args)); if (!sargs) return -ENOMEM; sargs->space_slots = 0; sargs->total_spaces = 0; ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs); if (ret < 0) { error("cannot get space info: %m"); free(sargs); return -errno; } /* This really should never happen */ if (!sargs->total_spaces) { free(sargs); return -ENOENT; } count = sargs->total_spaces; free(sargs); sargs = malloc(sizeof(struct btrfs_ioctl_space_args) + (count * sizeof(struct btrfs_ioctl_space_info))); if (!sargs) return -ENOMEM; sargs->space_slots = count; sargs->total_spaces = 0; ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs); if (ret < 0) { error("cannot get space info with %llu slots: %m", count); free(sargs); return -errno; } *sargs_ret = sargs; return 0; } static u64 find_max_device_id(struct btrfs_ioctl_search_args *search_args, int nr_items) { struct btrfs_dev_item *dev_item; char *buf = search_args->buf; buf += (nr_items - 1) * (sizeof(struct btrfs_ioctl_search_header) + sizeof(struct btrfs_dev_item)); buf += sizeof(struct btrfs_ioctl_search_header); dev_item = (struct btrfs_dev_item *)buf; return btrfs_stack_device_id(dev_item); } static int search_chunk_tree_for_fs_info(int fd, struct btrfs_ioctl_fs_info_args *fi_args) { int ret; int max_items; u64 start_devid = 1; struct btrfs_ioctl_search_args search_args; struct btrfs_ioctl_search_key *search_key = &search_args.key; fi_args->num_devices = 0; max_items = BTRFS_SEARCH_ARGS_BUFSIZE / (sizeof(struct btrfs_ioctl_search_header) + sizeof(struct btrfs_dev_item)); search_key->tree_id = BTRFS_CHUNK_TREE_OBJECTID; search_key->min_objectid = BTRFS_DEV_ITEMS_OBJECTID; search_key->max_objectid = BTRFS_DEV_ITEMS_OBJECTID; search_key->min_type = BTRFS_DEV_ITEM_KEY; search_key->max_type = BTRFS_DEV_ITEM_KEY; search_key->min_transid = 0; search_key->max_transid = (u64)-1; search_key->nr_items = max_items; search_key->max_offset = (u64)-1; again: search_key->min_offset = start_devid; ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &search_args); if (ret < 0) return -errno; fi_args->num_devices += (u64)search_key->nr_items; if (search_key->nr_items == max_items) { start_devid = find_max_device_id(&search_args, search_key->nr_items) + 1; goto again; } /* Get the latest max_id to stay consistent with the num_devices */ if (search_key->nr_items == 0) /* * last tree_search returns an empty buf, use the devid of * the last dev_item of the previous tree_search */ fi_args->max_id = start_devid - 1; else fi_args->max_id = find_max_device_id(&search_args, search_key->nr_items); return 0; } /* * For a given path, fill in the ioctl fs_ and info_ args. * If the path is a btrfs mountpoint, fill info for all devices. * If the path is a btrfs device, fill in only that device. * * The path provided must be either on a mounted btrfs fs, * or be a mounted btrfs device. * * Returns 0 on success, or a negative errno. */ int get_fs_info(const char *path, struct btrfs_ioctl_fs_info_args *fi_args, struct btrfs_ioctl_dev_info_args **di_ret) { int fd = -1; int ret = 0; int ndevs = 0; u64 last_devid = 0; int replacing = 0; struct btrfs_fs_devices *fs_devices_mnt = NULL; struct btrfs_ioctl_dev_info_args *di_args; struct btrfs_ioctl_dev_info_args tmp; char mp[PATH_MAX]; DIR *dirstream = NULL; memset(fi_args, 0, sizeof(*fi_args)); if (path_is_block_device(path) == 1) { struct btrfs_super_block *disk_super; char buf[BTRFS_SUPER_INFO_SIZE]; /* Ensure it's mounted, then set path to the mountpoint */ fd = open(path, O_RDONLY); if (fd < 0) { ret = -errno; error("cannot open %s: %m", path); goto out; } ret = check_mounted_where(fd, path, mp, sizeof(mp), &fs_devices_mnt, SBREAD_DEFAULT); if (!ret) { ret = -EINVAL; goto out; } if (ret < 0) goto out; path = mp; /* Only fill in this one device */ fi_args->num_devices = 1; disk_super = (struct btrfs_super_block *)buf; ret = btrfs_read_dev_super(fd, disk_super, BTRFS_SUPER_INFO_OFFSET, 0); if (ret < 0) { ret = -EIO; goto out; } last_devid = btrfs_stack_device_id(&disk_super->dev_item); fi_args->max_id = last_devid; memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE); close(fd); } /* at this point path must not be for a block device */ fd = open_file_or_dir(path, &dirstream); if (fd < 0) { ret = -errno; goto out; } /* fill in fi_args if not just a single device */ if (fi_args->num_devices != 1) { ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args); if (ret < 0) { ret = -errno; goto out; } /* * The fs_args->num_devices does not include seed devices */ ret = search_chunk_tree_for_fs_info(fd, fi_args); if (ret) goto out; /* * search_chunk_tree_for_fs_info() will lacks the devid 0 * so manual probe for it here. */ ret = get_device_info(fd, 0, &tmp); if (!ret) { fi_args->num_devices++; ndevs++; replacing = 1; if (last_devid == 0) last_devid++; } } if (!fi_args->num_devices) goto out; di_args = *di_ret = malloc((fi_args->num_devices) * sizeof(*di_args)); if (!di_args) { ret = -errno; goto out; } if (replacing) memcpy(di_args, &tmp, sizeof(tmp)); for (; last_devid <= fi_args->max_id && ndevs < fi_args->num_devices; last_devid++) { ret = get_device_info(fd, last_devid, &di_args[ndevs]); if (ret == -ENODEV) continue; if (ret) goto out; ndevs++; } /* * only when the only dev we wanted to find is not there then * let any error be returned */ if (fi_args->num_devices != 1) { BUG_ON(ndevs == 0); ret = 0; } out: close_file_or_dir(fd, dirstream); return ret; } int get_fsid_fd(int fd, u8 *fsid) { int ret; struct btrfs_ioctl_fs_info_args args; ret = ioctl(fd, BTRFS_IOC_FS_INFO, &args); if (ret < 0) return -errno; memcpy(fsid, args.fsid, BTRFS_FSID_SIZE); return 0; } int get_fsid(const char *path, u8 *fsid, int silent) { int ret; int fd; fd = open(path, O_RDONLY); if (fd < 0) { if (!silent) error("failed to open %s: %m", path); return -errno; } ret = get_fsid_fd(fd, fsid); close(fd); return ret; } static int group_profile_devs_min(u64 flag) { switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) { case 0: /* single */ case BTRFS_BLOCK_GROUP_DUP: return 1; case BTRFS_BLOCK_GROUP_RAID0: case BTRFS_BLOCK_GROUP_RAID1: case BTRFS_BLOCK_GROUP_RAID5: return 2; case BTRFS_BLOCK_GROUP_RAID6: case BTRFS_BLOCK_GROUP_RAID1C3: return 3; case BTRFS_BLOCK_GROUP_RAID10: case BTRFS_BLOCK_GROUP_RAID1C4: return 4; default: return -1; } } int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile, u64 dev_cnt, int mixed, int ssd) { u64 allowed = 0; u64 profile = metadata_profile | data_profile; switch (dev_cnt) { default: case 4: allowed |= BTRFS_BLOCK_GROUP_RAID10; allowed |= BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_RAID1C4; /* fallthrough */ case 3: allowed |= BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID1C3; /* fallthrough */ case 2: allowed |= BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5; /* fallthrough */ case 1: allowed |= BTRFS_BLOCK_GROUP_DUP; } if (dev_cnt > 1 && profile & BTRFS_BLOCK_GROUP_DUP) { warning("DUP is not recommended on filesystem with multiple devices"); } if (metadata_profile & ~allowed) { fprintf(stderr, "ERROR: unable to create FS with metadata profile %s " "(have %llu devices but %d devices are required)\n", btrfs_group_profile_str(metadata_profile), dev_cnt, group_profile_devs_min(metadata_profile)); return 1; } if (data_profile & ~allowed) { fprintf(stderr, "ERROR: unable to create FS with data profile %s " "(have %llu devices but %d devices are required)\n", btrfs_group_profile_str(data_profile), dev_cnt, group_profile_devs_min(data_profile)); return 1; } if (dev_cnt == 3 && profile & BTRFS_BLOCK_GROUP_RAID6) { warning("RAID6 is not recommended on filesystem with 3 devices only"); } if (dev_cnt == 2 && profile & BTRFS_BLOCK_GROUP_RAID5) { warning("RAID5 is not recommended on filesystem with 2 devices only"); } warning_on(!mixed && (data_profile & BTRFS_BLOCK_GROUP_DUP) && ssd, "DUP may not actually lead to 2 copies on the device, see manual page"); return 0; } int group_profile_max_safe_loss(u64 flags) { switch (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) { case 0: /* single */ case BTRFS_BLOCK_GROUP_DUP: case BTRFS_BLOCK_GROUP_RAID0: return 0; case BTRFS_BLOCK_GROUP_RAID1: case BTRFS_BLOCK_GROUP_RAID5: case BTRFS_BLOCK_GROUP_RAID10: return 1; case BTRFS_BLOCK_GROUP_RAID6: case BTRFS_BLOCK_GROUP_RAID1C3: return 2; case BTRFS_BLOCK_GROUP_RAID1C4: return 3; default: return -1; } } /* * This reads a line from the stdin and only returns non-zero if the * first whitespace delimited token is a case insensitive match with yes * or y. */ int ask_user(const char *question) { char buf[30] = {0,}; char *saveptr = NULL; char *answer; printf("%s [y/N]: ", question); return fgets(buf, sizeof(buf) - 1, stdin) && (answer = strtok_r(buf, " \t\n\r", &saveptr)) && (!strcasecmp(answer, "yes") || !strcasecmp(answer, "y")); } /* * Use libmount to compare the subvol passed with the pathname of the directory * mounted in btrfs. The pathname inside btrfs is different from getmnt and * friends, since it can detect bind mounts to content from the inside of the * original mount. * * Example: * # mount -o subvol=/vol /dev/sda2 /mnt * # mount --bind /mnt/dir2 /othermnt * * # mounts * ... * /dev/sda2 on /mnt type btrfs (ro,relatime,ssd,space_cache,subvolid=256,subvol=/vol) * /dev/sda2 on /othermnt type btrfs (ro,relatime,ssd,space_cache,subvolid=256,subvol=/vol) * * # cat /proc/self/mountinfo * * 38 30 0:32 /vol /mnt ro,relatime - btrfs /dev/sda2 ro,ssd,space_cache,subvolid=256,subvol=/vol * 37 29 0:32 /vol/dir2 /othermnt ro,relatime - btrfs /dev/sda2 ro,ssd,space_cache,subvolid=256,subvol=/vol * * If we try to find a mounpoint only using subvol and subvolid from mount * options we would get mislead to belive that /othermnt has the same content * from /mnt. * * But, using mountinfo, we have the pathaname _inside_ the filesystem, so we * can filter out the mount points with bind mounts which has different content * from the original mounts, in this case the mount point with id 37. */ int find_mount_fsroot(const char *subvol, const char *subvolid, char **mount) { struct libmnt_cache *cache; struct libmnt_iter *iter; struct libmnt_fs *fs; struct libmnt_table *tb; tb = mnt_new_table_from_file("/proc/self/mountinfo"); if (!tb) return -1; iter = mnt_new_iter(MNT_ITER_FORWARD); if (!iter) goto out_table; cache = mnt_new_cache(); if (!cache) goto out_iter; if (mnt_table_set_cache(tb, cache)) goto out_cache; while (mnt_table_next_fs(tb, iter, &fs) == 0) { const char *mnt_root = mnt_fs_get_root(fs); bool found = true; char *subid = NULL; size_t id_siz; /* * Check any combination that would lead to an undesired mount * point and remove from the table. */ if (strcmp(mnt_fs_get_fstype(fs), "btrfs") != 0) found = false; else if (strlen(mnt_root) != strlen(subvol)) found = false; else if (strcmp(mnt_root, subvol) != 0) found = false; else if (mnt_fs_get_option(fs, "subvolid", &subid, &id_siz)) found = false; else if (strncmp(subid, subvolid, id_siz) != 0) found = false; if (!found) mnt_table_remove_fs(tb, fs); } /* Rewind the iterator to make second pass */ mnt_reset_iter(iter, MNT_ITER_FORWARD); /* * What remains in the list are the mount itself and possible bind mounts * referring to the same pathname mounted by the original mount. As in * this case the mount point would have the same content of the original * mount, we can safely return the first entry. */ if (!mnt_table_is_empty(tb)) { mnt_table_next_fs(tb, iter, &fs); *mount = strdup(mnt_fs_get_target(fs)); } return 0; out_cache: mnt_unref_cache(cache); out_iter: mnt_free_iter(iter); out_table: mnt_unref_table(tb); return -1; } /* * return 0 if a btrfs mount point is found * return 1 if a mount point is found but not btrfs * return <0 if something goes wrong */ int find_mount_root(const char *path, char **mount_root) { FILE *mnttab; int fd; struct mntent *ent; int len; int ret = 0; int not_btrfs = 1; int longest_matchlen = 0; char *longest_match = NULL; fd = open(path, O_RDONLY | O_NOATIME); if (fd < 0) return -errno; close(fd); mnttab = setmntent("/proc/self/mounts", "r"); if (!mnttab) return -errno; while ((ent = getmntent(mnttab))) { len = strlen(ent->mnt_dir); if (strncmp(ent->mnt_dir, path, len) == 0) { /* match found and use the latest match */ if (longest_matchlen <= len) { free(longest_match); longest_matchlen = len; longest_match = strdup(ent->mnt_dir); if (!longest_match) { ret = -errno; break; } not_btrfs = strcmp(ent->mnt_type, "btrfs"); } } } endmntent(mnttab); if (ret) return ret; if (!longest_match) return -ENOENT; if (not_btrfs) { free(longest_match); return 1; } ret = 0; *mount_root = realpath(longest_match, NULL); if (!*mount_root) ret = -errno; free(longest_match); return ret; } void units_set_mode(unsigned *units, unsigned mode) { unsigned base = *units & UNITS_MODE_MASK; *units = base | mode; } void units_set_base(unsigned *units, unsigned base) { unsigned mode = *units & ~UNITS_MODE_MASK; *units = base | mode; } int find_next_key(struct btrfs_path *path, struct btrfs_key *key) { int level; for (level = 0; level < BTRFS_MAX_LEVEL; level++) { if (!path->nodes[level]) break; if (path->slots[level] + 1 >= btrfs_header_nritems(path->nodes[level])) continue; if (level == 0) btrfs_item_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); else btrfs_node_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); return 0; } return 1; } const char* btrfs_group_type_str(u64 flag) { u64 mask = BTRFS_BLOCK_GROUP_TYPE_MASK | BTRFS_SPACE_INFO_GLOBAL_RSV; switch (flag & mask) { case BTRFS_BLOCK_GROUP_DATA: return "Data"; case BTRFS_BLOCK_GROUP_SYSTEM: return "System"; case BTRFS_BLOCK_GROUP_METADATA: return "Metadata"; case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA: return "Data+Metadata"; case BTRFS_SPACE_INFO_GLOBAL_RSV: return "GlobalReserve"; default: return "unknown"; } } const char* btrfs_group_profile_str(u64 flag) { switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) { case 0: return "single"; case BTRFS_BLOCK_GROUP_RAID0: return "RAID0"; case BTRFS_BLOCK_GROUP_RAID1: return "RAID1"; case BTRFS_BLOCK_GROUP_RAID1C3: return "RAID1C3"; case BTRFS_BLOCK_GROUP_RAID1C4: return "RAID1C4"; case BTRFS_BLOCK_GROUP_RAID5: return "RAID5"; case BTRFS_BLOCK_GROUP_RAID6: return "RAID6"; case BTRFS_BLOCK_GROUP_DUP: return "DUP"; case BTRFS_BLOCK_GROUP_RAID10: return "RAID10"; default: return "unknown"; } } /* * Check if the BTRFS_IOC_TREE_SEARCH_V2 ioctl is supported on a given * filesystem, opened at fd */ int btrfs_tree_search2_ioctl_supported(int fd) { struct btrfs_ioctl_search_args_v2 *args2; struct btrfs_ioctl_search_key *sk; int args2_size = 1024; char args2_buf[args2_size]; int ret; args2 = (struct btrfs_ioctl_search_args_v2 *)args2_buf; sk = &(args2->key); /* * Search for the extent tree item in the root tree. */ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID; sk->min_objectid = BTRFS_EXTENT_TREE_OBJECTID; sk->max_objectid = BTRFS_EXTENT_TREE_OBJECTID; sk->min_type = BTRFS_ROOT_ITEM_KEY; sk->max_type = BTRFS_ROOT_ITEM_KEY; sk->min_offset = 0; sk->max_offset = (u64)-1; sk->min_transid = 0; sk->max_transid = (u64)-1; sk->nr_items = 1; args2->buf_size = args2_size - sizeof(struct btrfs_ioctl_search_args_v2); ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH_V2, args2); if (ret == -EOPNOTSUPP) return 0; else if (ret == 0) return 1; return ret; } unsigned int get_unit_mode_from_arg(int *argc, char *argv[], int df_mode) { unsigned int unit_mode = UNITS_DEFAULT; int arg_i; int arg_end; for (arg_i = 0; arg_i < *argc; arg_i++) { if (!strcmp(argv[arg_i], "--")) break; if (!strcmp(argv[arg_i], "--raw")) { unit_mode = UNITS_RAW; argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--human-readable")) { unit_mode = UNITS_HUMAN_BINARY; argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--iec")) { units_set_mode(&unit_mode, UNITS_BINARY); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--si")) { units_set_mode(&unit_mode, UNITS_DECIMAL); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--kbytes")) { units_set_base(&unit_mode, UNITS_KBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--mbytes")) { units_set_base(&unit_mode, UNITS_MBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--gbytes")) { units_set_base(&unit_mode, UNITS_GBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "--tbytes")) { units_set_base(&unit_mode, UNITS_TBYTES); argv[arg_i] = NULL; continue; } if (!df_mode) continue; if (!strcmp(argv[arg_i], "-b")) { unit_mode = UNITS_RAW; argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-h")) { unit_mode = UNITS_HUMAN_BINARY; argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-H")) { unit_mode = UNITS_HUMAN_DECIMAL; argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-k")) { units_set_base(&unit_mode, UNITS_KBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-m")) { units_set_base(&unit_mode, UNITS_MBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-g")) { units_set_base(&unit_mode, UNITS_GBYTES); argv[arg_i] = NULL; continue; } if (!strcmp(argv[arg_i], "-t")) { units_set_base(&unit_mode, UNITS_TBYTES); argv[arg_i] = NULL; continue; } } for (arg_i = 0, arg_end = 0; arg_i < *argc; arg_i++) { if (!argv[arg_i]) continue; argv[arg_end] = argv[arg_i]; arg_end++; } *argc = arg_end; return unit_mode; } u64 div_factor(u64 num, int factor) { if (factor == 10) return num; num *= factor; num /= 10; return num; } /* * Get the length of the string converted from a u64 number. * * Result is equal to log10(num) + 1, but without the use of math library. */ int count_digits(u64 num) { int ret = 0; if (num == 0) return 1; while (num > 0) { ret++; num /= 10; } return ret; } int string_is_numerical(const char *str) { if (!str) return 0; if (!(*str >= '0' && *str <= '9')) return 0; while (*str >= '0' && *str <= '9') str++; if (*str != '\0') return 0; return 1; } int prefixcmp(const char *str, const char *prefix) { for (; ; str++, prefix++) if (!*prefix) return 0; else if (*str != *prefix) return (unsigned char)*prefix - (unsigned char)*str; } const char *subvol_strip_mountpoint(const char *mnt, const char *full_path) { int len = strlen(mnt); if (!len) return full_path; if ((strncmp(mnt, full_path, len) != 0) || ((len > 1) && (full_path[len] != '/'))) { error("not on mount point: %s", mnt); exit(1); } if (mnt[len - 1] != '/') len += 1; return full_path + len; } /* Set the seed manually */ void init_rand_seed(u64 seed) { int i; /* only use the last 48 bits */ for (i = 0; i < 3; i++) { rand_seed[i] = (unsigned short)(seed ^ (unsigned short)(-1)); seed >>= 16; } rand_seed_initialized = 1; } static void __init_seed(void) { struct timeval tv; int ret; int fd; if(rand_seed_initialized) return; /* Use urandom as primary seed source. */ fd = open("/dev/urandom", O_RDONLY); if (fd >= 0) { ret = read(fd, rand_seed, sizeof(rand_seed)); close(fd); if (ret < sizeof(rand_seed)) goto fallback; } else { fallback: /* Use time and pid as fallback seed */ warning("failed to read /dev/urandom, use time and pid as random seed"); gettimeofday(&tv, 0); rand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF); rand_seed[1] = getppid() ^ (tv.tv_usec & 0xFFFF); rand_seed[2] = (tv.tv_sec ^ tv.tv_usec) >> 16; } rand_seed_initialized = 1; } u32 rand_u32(void) { __init_seed(); /* * Don't use nrand48, its range is [0,2^31) The highest bit will always * be 0. Use jrand48 to include the highest bit. */ return (u32)jrand48(rand_seed); } /* Return random number in range [0, upper) */ unsigned int rand_range(unsigned int upper) { __init_seed(); /* * Use the full 48bits to mod, which would be more uniformly * distributed */ return (unsigned int)(jrand48(rand_seed) % upper); } int rand_int(void) { return (int)(rand_u32()); } u64 rand_u64(void) { u64 ret = 0; ret += rand_u32(); ret <<= 32; ret += rand_u32(); return ret; } u16 rand_u16(void) { return (u16)(rand_u32()); } u8 rand_u8(void) { return (u8)(rand_u32()); } void btrfs_config_init(void) { bconf.output_format = CMD_FORMAT_TEXT; bconf.verbose = BTRFS_BCONF_UNSET; } void bconf_be_verbose(void) { if (bconf.verbose == BTRFS_BCONF_UNSET) bconf.verbose = 1; else bconf.verbose++; } void bconf_be_quiet(void) { bconf.verbose = BTRFS_BCONF_QUIET; } /* Returns total size of main memory in bytes, -1UL if error. */ unsigned long total_memory(void) { struct sysinfo si; if (sysinfo(&si) < 0) { error("can't determine memory size"); return -1UL; } return si.totalram * si.mem_unit; /* bytes */ } void print_device_info(struct btrfs_device *device, char *prefix) { if (prefix) printf("%s", prefix); printf("Device: id = %llu, name = %s\n", device->devid, device->name); } void print_all_devices(struct list_head *devices) { struct btrfs_device *dev; printf("All Devices:\n"); list_for_each_entry(dev, devices, dev_list) print_device_info(dev, "\t"); printf("\n"); } static int bit_count(u64 x) { int ret = 0; while (x) { if (x & 1) ret++; x >>= 1; } return ret; } static char *sprint_profiles(u64 profiles) { int i; int maxlen = 1; char *ptr; if (bit_count(profiles) <= 1) return NULL; for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) maxlen += strlen(btrfs_raid_array[i].raid_name) + 2; ptr = calloc(1, maxlen); if (!ptr) return NULL; if (profiles & BTRFS_AVAIL_ALLOC_BIT_SINGLE) strcat(ptr, btrfs_raid_array[BTRFS_RAID_SINGLE].raid_name); for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { if (!(btrfs_raid_array[i].bg_flag & profiles)) continue; if (ptr[0]) strcat(ptr, ", "); strcat(ptr, btrfs_raid_array[i].raid_name); } return ptr; } static int btrfs_get_string_for_multiple_profiles(int fd, char **data_ret, char **metadata_ret, char **mixed_ret, char **system_ret, char **types_ret) { int ret; int i; struct btrfs_ioctl_space_args *sargs; u64 data_profiles = 0; u64 metadata_profiles = 0; u64 system_profiles = 0; u64 mixed_profiles = 0; const u64 mixed_profile_fl = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; ret = get_df(fd, &sargs); if (ret < 0) return -1; for (i = 0; i < sargs->total_spaces; i++) { u64 flags = sargs->spaces[i].flags; if (!(flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)) flags |= BTRFS_AVAIL_ALLOC_BIT_SINGLE; if ((flags & mixed_profile_fl) == mixed_profile_fl) mixed_profiles |= flags; else if (flags & BTRFS_BLOCK_GROUP_DATA) data_profiles |= flags; else if (flags & BTRFS_BLOCK_GROUP_METADATA) metadata_profiles |= flags; else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) system_profiles |= flags; } free(sargs); data_profiles &= BTRFS_EXTENDED_PROFILE_MASK; system_profiles &= BTRFS_EXTENDED_PROFILE_MASK; mixed_profiles &= BTRFS_EXTENDED_PROFILE_MASK; metadata_profiles &= BTRFS_EXTENDED_PROFILE_MASK; *data_ret = sprint_profiles(data_profiles); *metadata_ret = sprint_profiles(metadata_profiles); *mixed_ret = sprint_profiles(mixed_profiles); *system_ret = sprint_profiles(system_profiles); if (types_ret) { *types_ret = calloc(1, 64); if (!*types_ret) goto out; if (*data_ret) strcat(*types_ret, "data"); if (*metadata_ret) { if ((*types_ret)[0]) strcat(*types_ret, ", "); strcat(*types_ret, "metadata"); } if (*mixed_ret) { if ((*types_ret)[0]) strcat(*types_ret, ", "); strcat(*types_ret, "data+metadata"); } if (*system_ret) { if ((*types_ret)[0]) strcat(*types_ret, ", "); strcat(*types_ret, "system"); } } out: return *data_ret || *metadata_ret || *mixed_ret || *system_ret; } /* * Return string containing coma separated list of block group types that * contain multiple profiles. The return value must be freed by the caller. */ char *btrfs_test_for_multiple_profiles(int fd) { char *data, *metadata, *system, *mixed, *types; btrfs_get_string_for_multiple_profiles(fd, &data, &metadata, &mixed, &system, &types); free(data); free(metadata); free(mixed); free(system); return types; } int btrfs_warn_multiple_profiles(int fd) { int ret; char *data_prof, *mixed_prof, *metadata_prof, *system_prof; ret = btrfs_get_string_for_multiple_profiles(fd, &data_prof, &metadata_prof, &mixed_prof, &system_prof, NULL); if (ret != 1) return ret; fprintf(stderr, "WARNING: Multiple block group profiles detected, see 'man btrfs(5)'.\n"); if (data_prof) fprintf(stderr, "WARNING: Data: %s\n", data_prof); if (metadata_prof) fprintf(stderr, "WARNING: Metadata: %s\n", metadata_prof); if (mixed_prof) fprintf(stderr, "WARNING: Data+Metadata: %s\n", mixed_prof); if (system_prof) fprintf(stderr, "WARNING: System: %s\n", system_prof); free(data_prof); free(metadata_prof); free(mixed_prof); free(system_prof); return 1; } /* * Open a file in fsid directory in sysfs and return the file descriptor or * error */ int sysfs_open_fsid_file(int fd, const char *filename) { u8 fsid[BTRFS_UUID_SIZE]; char fsid_str[BTRFS_UUID_UNPARSED_SIZE]; char sysfs_file[PATH_MAX]; int ret; ret = get_fsid_fd(fd, fsid); if (ret < 0) return ret; uuid_unparse(fsid, fsid_str); ret = path_cat3_out(sysfs_file, "/sys/fs/btrfs", fsid_str, filename); if (ret < 0) return ret; return open(sysfs_file, O_RDONLY); } /* * Read up to @size bytes to @buf from @fd */ int sysfs_read_file(int fd, char *buf, size_t size) { lseek(fd, 0, SEEK_SET); memset(buf, 0, size); return read(fd, buf, size); } static const char exclop_def[][16] = { [BTRFS_EXCLOP_NONE] "none", [BTRFS_EXCLOP_BALANCE] "balance", [BTRFS_EXCLOP_DEV_ADD] "device add", [BTRFS_EXCLOP_DEV_REMOVE] "device remove", [BTRFS_EXCLOP_DEV_REPLACE] "device replace", [BTRFS_EXCLOP_RESIZE] "resize", [BTRFS_EXCLOP_SWAP_ACTIVATE] "swap activate", }; /* * Read currently running exclusive operation from sysfs. If this is not * available, return BTRFS_EXCLOP_UNKNOWN */ int get_fs_exclop(int fd) { int sysfs_fd; char buf[32]; int ret; int i; sysfs_fd = sysfs_open_fsid_file(fd, "exclusive_operation"); if (sysfs_fd < 0) return BTRFS_EXCLOP_UNKNOWN; memset(buf, 0, sizeof(buf)); ret = sysfs_read_file(sysfs_fd, buf, sizeof(buf)); close(sysfs_fd); if (ret <= 0) return BTRFS_EXCLOP_UNKNOWN; i = strlen(buf) - 1; while (i > 0 && isspace(buf[i])) i--; if (i > 0) buf[i + 1] = 0; for (i = 0; i < ARRAY_SIZE(exclop_def); i++) { if (strcmp(exclop_def[i], buf) == 0) return i; } return BTRFS_EXCLOP_UNKNOWN; } const char *get_fs_exclop_name(int op) { if (0 <= op && op <= ARRAY_SIZE(exclop_def)) return exclop_def[op]; return "UNKNOWN"; } /* * Check if there's another exclusive operation running and either return error * or wait until there's none in case @enqueue is true. The timeout between * checks is 1 minute as we get notification on the sysfs file when the * operation finishes. * * Return: * 0 - caller can continue, nothing running or the status is not available * 1 - another operation running * <0 - there was another error */ int check_running_fs_exclop(int fd, enum exclusive_operation start, bool enqueue) { int sysfs_fd; int exclop; int ret; sysfs_fd = sysfs_open_fsid_file(fd, "exclusive_operation"); if (sysfs_fd < 0) { if (errno == ENOENT) return 0; return -errno; } exclop = get_fs_exclop(fd); if (exclop <= 0) { ret = 0; goto out; } if (!enqueue) { error( "unable to start %s, another exclusive operation '%s' in progress", get_fs_exclop_name(start), get_fs_exclop_name(exclop)); ret = 1; goto out; } while (exclop > 0) { fd_set fds; struct timeval tv = { .tv_sec = 60, .tv_usec = 0 }; FD_ZERO(&fds); FD_SET(sysfs_fd, &fds); ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); if (ret < 0) { ret = -errno; break; } if (ret > 0) { /* * Notified before the timeout, check again before * returning. In case there are more operations * waiting, we want to reduce the chances to race so * reuse the remaining time to randomize the order. */ tv.tv_sec /= 2; ret = select(sysfs_fd + 1, NULL, NULL, &fds, &tv); exclop = get_fs_exclop(fd); continue; } } out: close(sysfs_fd); return ret; } #ifdef STATICBUILD /* * libmount links with selinux that we don't use, the following symbols are * missing. Weak aliases allow to link. */ __attribute__((weak)) int selinux_trans_to_raw_context(const char * trans, char ** rawp) { return -1; } typedef void *security_context_t; __attribute__((weak)) void freecon(security_context_t con) { } #endif