X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Fbtrfs-util.c;h=b34ac8b15a80260c13cef09701bf1673d79d84df;hb=86caf09519c702f38552ba4f789b55a562fc29c5;hp=e648121b47fe593d0ad87cb8d125b63a1080c2e2;hpb=f27a386430cc7a27ebd06899d93310fb3bd4cee7;p=elogind.git diff --git a/src/shared/btrfs-util.c b/src/shared/btrfs-util.c index e648121b4..b34ac8b15 100644 --- a/src/shared/btrfs-util.c +++ b/src/shared/btrfs-util.c @@ -228,14 +228,18 @@ int btrfs_subvol_remove(const char *path) { return 0; } -int btrfs_subvol_set_read_only(const char *path, bool b) { - _cleanup_close_ int fd = -1; +int btrfs_subvol_set_read_only_fd(int fd, bool b) { uint64_t flags, nflags; + struct stat st; - fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC); - if (fd < 0) + assert(fd >= 0); + + if (fstat(fd, &st) < 0) return -errno; + if (!S_ISDIR(st.st_mode) || st.st_ino != 256) + return -EINVAL; + if (ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags) < 0) return -errno; @@ -253,6 +257,16 @@ int btrfs_subvol_set_read_only(const char *path, bool b) { return 0; } +int btrfs_subvol_set_read_only(const char *path, bool b) { + _cleanup_close_ int fd = -1; + + fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (fd < 0) + return -errno; + + return btrfs_subvol_set_read_only_fd(fd, b); +} + int btrfs_subvol_get_read_only_fd(int fd) { uint64_t flags; @@ -275,6 +289,26 @@ int btrfs_reflink(int infd, int outfd) { return 0; } +int btrfs_clone_range(int infd, uint64_t in_offset, int outfd, uint64_t out_offset, uint64_t sz) { + struct btrfs_ioctl_clone_range_args args = { + .src_fd = infd, + .src_offset = in_offset, + .src_length = sz, + .dest_offset = out_offset, + }; + int r; + + assert(infd >= 0); + assert(outfd >= 0); + assert(sz > 0); + + r = ioctl(outfd, BTRFS_IOC_CLONE_RANGE, &args); + if (r < 0) + return -errno; + + return 0; +} + int btrfs_get_block_device(const char *path, dev_t *dev) { struct btrfs_ioctl_fs_info_args fsi = {}; _cleanup_close_ int fd = -1; @@ -338,6 +372,77 @@ int btrfs_subvol_get_id_fd(int fd, uint64_t *ret) { return 0; } +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_t) -1) { + args->key.min_offset++; + return true; + } + + if (args->key.min_type < (uint8_t) -1) { + args->key.min_type++; + args->key.min_offset = 0; + return true; + } + + if (args->key.min_objectid < (uint64_t) -1) { + 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) { + assert(args); + + /* Compare min and max */ + + if (args->key.min_objectid < args->key.max_objectid) + return -1; + if (args->key.min_objectid > args->key.max_objectid) + return 1; + + if (args->key.min_type < args->key.max_type) + return -1; + if (args->key.min_type > args->key.max_type) + return 1; + + if (args->key.min_offset < args->key.max_offset) + return -1; + if (args->key.min_offset > args->key.max_offset) + return 1; + + return 0; +} + +#define FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) \ + for ((i) = 0, \ + (sh) = (const struct btrfs_ioctl_search_header*) (args).buf; \ + (i) < (args).key.nr_items; \ + (i)++, \ + (sh) = (const struct btrfs_ioctl_search_header*) ((uint8_t*) (sh) + sizeof(struct btrfs_ioctl_search_header) + (sh)->len)) + +#define BTRFS_IOCTL_SEARCH_HEADER_BODY(sh) \ + ((void*) ((uint8_t*) sh + sizeof(struct btrfs_ioctl_search_header))) + int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *ret) { struct btrfs_ioctl_search_args args = { /* Tree of tree roots */ @@ -347,9 +452,10 @@ int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *ret) { .key.min_type = BTRFS_ROOT_ITEM_KEY, .key.max_type = BTRFS_ROOT_ITEM_KEY, - /* No restrictions on the other components */ .key.min_offset = 0, .key.max_offset = (uint64_t) -1, + + /* No restrictions on the other components */ .key.min_transid = 0, .key.max_transid = (uint64_t) -1, }; @@ -367,7 +473,7 @@ int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *ret) { args.key.min_objectid = args.key.max_objectid = subvol_id; - for (;;) { + while (btrfs_ioctl_search_args_compare(&args) <= 0) { const struct btrfs_ioctl_search_header *sh; unsigned i; @@ -378,25 +484,23 @@ int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *ret) { if (args.key.nr_items <= 0) break; - for (i = 0, - sh = (const struct btrfs_ioctl_search_header*) args.buf; - i < args.key.nr_items; - i++, - args.key.min_type = sh->type, - args.key.min_offset = sh->offset, - args.key.min_objectid = sh->objectid, - sh = (const struct btrfs_ioctl_search_header*) ((uint8_t*) sh + sizeof(struct btrfs_ioctl_search_header) + sh->len)) { + FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) { const struct btrfs_root_item *ri; + /* 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; - ri = (const struct btrfs_root_item *)(args.buf + sizeof(struct btrfs_ioctl_search_header)); + ri = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh); ret->otime = (usec_t) le64toh(ri->otime.sec) * USEC_PER_SEC + (usec_t) le32toh(ri->otime.nsec) / NSEC_PER_USEC; @@ -412,8 +516,8 @@ int btrfs_subvol_get_info_fd(int fd, BtrfsSubvolInfo *ret) { goto finish; } - args.key.min_offset++; - if (!args.key.min_offset) /* overflow */ + /* Increase search key by one, to read the next item, if we can. */ + if (!btrfs_ioctl_search_args_inc(&args)) break; } @@ -430,13 +534,14 @@ int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *ret) { /* 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, - .key.min_objectid = 0, - .key.max_objectid = 0, - /* No restrictions on the other components */ .key.min_transid = 0, .key.max_transid = (uint64_t) -1, @@ -455,7 +560,7 @@ int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *ret) { args.key.min_offset = args.key.max_offset = subvol_id; - for (;;) { + while (btrfs_ioctl_search_args_compare(&args) <= 0) { const struct btrfs_ioctl_search_header *sh; unsigned i; @@ -466,26 +571,18 @@ int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *ret) { if (args.key.nr_items <= 0) break; - for (i = 0, - sh = (const struct btrfs_ioctl_search_header*) args.buf; - i < args.key.nr_items; - i++, - args.key.min_type = sh->type, - args.key.min_offset = sh->offset, - args.key.min_objectid = sh->objectid, - sh = (const struct btrfs_ioctl_search_header*) ((uint8_t*) sh + sizeof(struct btrfs_ioctl_search_header) + sh->len)) { + FOREACH_BTRFS_IOCTL_SEARCH_HEADER(i, sh, args) { - const void *body; + /* 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 != subvol_id) continue; - body = (uint8_t*) sh + sizeof(struct btrfs_ioctl_search_header); - if (sh->type == BTRFS_QGROUP_INFO_KEY) { - const struct btrfs_qgroup_info_item *qii = body; + const struct btrfs_qgroup_info_item *qii = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh); ret->referred = le64toh(qii->rfer); ret->exclusive = le64toh(qii->excl); @@ -493,7 +590,7 @@ int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *ret) { found_info = true; } else if (sh->type == BTRFS_QGROUP_LIMIT_KEY) { - const struct btrfs_qgroup_limit_item *qli = body; + const struct btrfs_qgroup_limit_item *qli = BTRFS_IOCTL_SEARCH_HEADER_BODY(sh); ret->referred_max = le64toh(qli->max_rfer); ret->exclusive_max = le64toh(qli->max_excl); @@ -510,8 +607,8 @@ int btrfs_subvol_get_quota_fd(int fd, BtrfsQuotaInfo *ret) { goto finish; } - args.key.min_offset++; - if (!args.key.min_offset) + /* Increase search key by one, to read the next item, if we can. */ + if (!btrfs_ioctl_search_args_inc(&args)) break; }