]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - bcache.c
Fix help for --compression-type
[bcachefs-tools-debian] / bcache.c
index fe214833672cb356e38d7a165c0f10149f047ea8..3cb5dfe99db03eef41954f9a556a54bcfe5f7602 100644 (file)
--- a/bcache.c
+++ b/bcache.c
 
 #include "bcache.h"
 
-#define __KERNEL__
-#include <linux/bcache-ioctl.h>
-#undef __KERNEL__
-
 const char * const cache_state[] = {
        "active",
        "ro",
@@ -48,6 +44,21 @@ const char * const csum_types[] = {
        NULL
 };
 
+const char * const compression_types[] = {
+       "none",
+       "lzo1x",
+       "gzip",
+       "xz",
+       NULL
+};
+
+const char * const error_actions[] = {
+       "continue",
+       "readonly",
+       "panic",
+       NULL
+};
+
 const char * const bdev_cache_mode[] = {
        "writethrough",
        "writeback",
@@ -150,11 +161,8 @@ ssize_t read_string_list_or_die(const char *opt, const char * const list[],
                                const char *msg)
 {
        ssize_t v = read_string_list(opt, list);
-       if (v < 0) {
-               fprintf(stderr, "Bad %s %s\n", msg, opt);
-               exit(EXIT_FAILURE);
-
-       }
+       if (v < 0)
+               die("Bad %s %s", msg, opt);
 
        return v;
 }
@@ -391,8 +399,7 @@ static uint64_t bch_checksum_update(unsigned type, uint64_t crc, const void *dat
        case BCH_CSUM_CRC64:
                return bch_crc64_update(crc, data, len);
        default:
-               fprintf(stderr, "Unknown checksum type %u\n", type);
-               exit(EXIT_FAILURE);
+               die("Unknown checksum type %u", type);
        }
 }
 
@@ -447,258 +454,51 @@ unsigned hatoi_validate(const char *s, const char *msg)
 {
        uint64_t v = hatoi(s);
 
-       if (v & (v - 1)) {
-               fprintf(stderr, "%s must be a power of two\n", msg);
-               exit(EXIT_FAILURE);
-       }
+       if (v & (v - 1))
+               die("%s must be a power of two", msg);
 
        v /= 512;
 
-       if (v > USHRT_MAX) {
-               fprintf(stderr, "%s too large\n", msg);
-               exit(EXIT_FAILURE);
-       }
+       if (v > USHRT_MAX)
+               die("%s too large\n", msg);
 
-       if (!v) {
-               fprintf(stderr, "%s too small\n", msg);
-               exit(EXIT_FAILURE);
-       }
+       if (!v)
+               die("%s too small\n", msg);
 
        return v;
 }
 
-static void do_write_sb(int fd, struct cache_sb *sb)
-{
-       char zeroes[SB_START] = {0};
-       size_t bytes = ((void *) __bset_bkey_last(sb)) - (void *) sb;
-
-       /* Zero start of disk */
-       if (pwrite(fd, zeroes, SB_START, 0) != SB_START) {
-               perror("write error trying to zero start of disk\n");
-               exit(EXIT_FAILURE);
-       }
-       /* Write superblock */
-       if (pwrite(fd, sb, bytes, SB_START) != bytes) {
-               perror("write error trying to write superblock\n");
-               exit(EXIT_FAILURE);
-       }
-
-       fsync(fd);
-       close(fd);
-}
-
-void write_backingdev_sb(int fd, unsigned block_size, unsigned *bucket_sizes,
-                        unsigned mode, uint64_t data_offset, const char *label,
-                        uuid_le user_uuid, uuid_le set_uuid)
-{
-       char uuid_str[40], set_uuid_str[40];
-       struct cache_sb sb;
-
-       memset(&sb, 0, sizeof(struct cache_sb));
-
-       sb.offset       = SB_SECTOR;
-       sb.version      = BCACHE_SB_VERSION_BDEV;
-       sb.magic        = BCACHE_MAGIC;
-       uuid_generate(sb.disk_uuid.b);
-       sb.user_uuid    = user_uuid;
-       sb.set_uuid     = set_uuid;
-       sb.block_size   = block_size;
-
-       uuid_unparse(sb.disk_uuid.b, uuid_str);
-       uuid_unparse(sb.user_uuid.b, set_uuid_str);
-       if (label)
-               memcpy(sb.label, label, SB_LABEL_SIZE);
-
-       SET_BDEV_CACHE_MODE(&sb, mode);
-
-       if (data_offset != BDEV_DATA_START_DEFAULT) {
-               sb.version = BCACHE_SB_VERSION_BDEV_WITH_OFFSET;
-               sb.bdev_data_offset = data_offset;
-       }
-
-       sb.csum = csum_set(&sb, BCH_CSUM_CRC64);
-
-       printf("UUID:                   %s\n"
-              "Set UUID:               %s\n"
-              "version:                %u\n"
-              "block_size:             %u\n"
-              "data_offset:            %ju\n",
-              uuid_str, set_uuid_str,
-              (unsigned) sb.version,
-              sb.block_size,
-              data_offset);
-
-       do_write_sb(fd, &sb);
-}
-
-int dev_open(const char *dev, bool wipe_bcache)
+int dev_open(const char *dev)
 {
-       struct cache_sb sb;
        blkid_probe pr;
        int fd;
-       char err[MAX_PATH];
 
-       if ((fd = open(dev, O_RDWR|O_EXCL)) == -1) {
-               sprintf(err, "Can't open dev %s: %s\n", dev, strerror(errno));
-               goto err;
-       }
+       if ((fd = open(dev, O_RDWR|O_EXCL)) == -1)
+               die("Can't open dev %s: %s\n", dev, strerror(errno));
 
-       if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
-               sprintf(err, "Failed to read superblock");
-               goto err;
-       }
+       if (!(pr = blkid_new_probe()))
+               die("Failed to create a new probe");
+       if (blkid_probe_set_device(pr, fd, 0, 0))
+               die("failed to set probe to device");
 
-       if (!memcmp(&sb.magic, &BCACHE_MAGIC, 16) && !wipe_bcache) {
-               sprintf(err, "Already a bcache device on %s, "
-                       "overwrite with --wipe-bcache\n", dev);
-               goto err;
-       }
-
-       if (!(pr = blkid_new_probe())) {
-               sprintf(err, "Failed to create a new probe");
-               goto err;
-       }
-       if (blkid_probe_set_device(pr, fd, 0, 0)) {
-               sprintf(err, "failed to set probe to device");
-               goto err;
-       }
        /* enable ptable probing; superblock probing is enabled by default */
-       if (blkid_probe_enable_partitions(pr, true)) {
-               sprintf(err, "Failed to enable partitions on probe");
-               goto err;
-       }
-       if (!blkid_do_probe(pr)) {
+       if (blkid_probe_enable_partitions(pr, true))
+               die("Failed to enable partitions on probe");
+
+       if (!blkid_do_probe(pr))
                /* XXX wipefs doesn't know how to remove partition tables */
-               sprintf(err, "Device %s already has a non-bcache superblock, "
-                       "remove it using wipefs and wipefs -a\n", dev);
-               goto err;
-       }
+               die("Device %s already has a non-bcache superblock, "
+                   "remove it using wipefs and wipefs -a\n", dev);
 
        return fd;
-
-       err:
-               fprintf(stderr, "dev_open failed with: %s", err);
-               exit(EXIT_FAILURE);
 }
 
-static unsigned min_bucket_size(int num_bucket_sizes, unsigned *bucket_sizes)
-{
-       int i;
-       unsigned min = bucket_sizes[0];
-
-       for (i = 0; i < num_bucket_sizes; i++)
-               min = bucket_sizes[i] < min ? bucket_sizes[i] : min;
-
-       return min;
-}
-
-void write_cache_sbs(int *fds, struct cache_sb *sb,
-                    unsigned block_size, unsigned *bucket_sizes,
-                    int num_bucket_sizes)
-{
-       char uuid_str[40], set_uuid_str[40];
-       size_t i;
-       unsigned min_size = min_bucket_size(num_bucket_sizes, bucket_sizes);
-
-       sb->offset      = SB_SECTOR;
-       sb->version     = BCACHE_SB_VERSION_CDEV_V3;
-       sb->magic       = BCACHE_MAGIC;
-       sb->block_size  = block_size;
-       sb->u64s        = bch_journal_buckets_offset(sb);
-
-       /*
-        * don't have a userspace crc32c implementation handy, just always use
-        * crc64
-        */
-       SET_CACHE_SB_CSUM_TYPE(sb, BCH_CSUM_CRC64);
-
-       for (i = 0; i < sb->nr_in_set; i++) {
-               struct cache_member *m = sb->members + i;
-
-               if (num_bucket_sizes <= 1) {
-                       m->bucket_size = bucket_sizes[0];
-               } else {
-                       if (!bucket_sizes[i]) {
-                               printf("No bucket size specified for cache %zu,"
-                                      " using the default of %u",
-                                      i, bucket_sizes[0]);
-                               m->bucket_size = bucket_sizes[0];
-                       } else {
-                               m->bucket_size  = bucket_sizes[i];
-                       }
-               }
-
-               m->nbuckets             = getblocks(fds[i]) / m->bucket_size;
-               m->first_bucket         = (23 / m->bucket_size) + 1;
-
-               if (m->nbuckets < 1 << 7) {
-                       fprintf(stderr, "Not enough buckets: %llu, need %u\n",
-                               m->nbuckets, 1 << 7);
-                       exit(EXIT_FAILURE);
-               }
-       }
-
-       for (i = 0; i < sb->nr_in_set; i++) {
-               struct cache_member *m = sb->members + i;
-
-               SET_CACHE_BTREE_NODE_SIZE(sb, min_size);
-
-
-               sb->disk_uuid = m->uuid;
-               sb->nr_this_dev         = i;
-
-               sb->csum = csum_set(sb, CACHE_SB_CSUM_TYPE(sb));
-
-               uuid_unparse(sb->disk_uuid.b, uuid_str);
-               uuid_unparse(sb->user_uuid.b, set_uuid_str);
-               printf("UUID:                   %s\n"
-                      "Set UUID:               %s\n"
-                      "version:                %u\n"
-                      "nbuckets:               %llu\n"
-                      "block_size:             %u\n"
-                      "bucket_size:            %u\n"
-                      "nr_in_set:              %u\n"
-                      "nr_this_dev:            %u\n"
-                      "first_bucket:           %u\n",
-                      uuid_str, set_uuid_str,
-                      (unsigned) sb->version,
-                      m->nbuckets,
-                      sb->block_size,
-                      m->bucket_size,
-                      sb->nr_in_set,
-                      sb->nr_this_dev,
-                      m->first_bucket);
-
-               do_write_sb(fds[i], sb);
-       }
-}
-
-void next_cache_device(struct cache_sb *sb,
-                             unsigned replication_set,
-                             int tier,
-                             unsigned replacement_policy,
-                             bool discard)
-{
-       struct cache_member *m = sb->members + sb->nr_in_set;
-
-       SET_CACHE_REPLICATION_SET(m, replication_set);
-       SET_CACHE_TIER(m, tier);
-       SET_CACHE_REPLACEMENT(m, replacement_policy);
-       SET_CACHE_DISCARD(m, discard);
-       uuid_generate(m->uuid.b);
-
-       sb->nr_in_set++;
-}
-
-unsigned get_blocksize(const char *path)
+unsigned get_blocksize(const char *path, int fd)
 {
        struct stat statbuf;
 
-       if (stat(path, &statbuf)) {
-               fprintf(stderr, "Error statting %s: %s\n",
-                       path, strerror(errno));
-               exit(EXIT_FAILURE);
-       }
+       if (fstat(fd, &statbuf))
+               die("Error statting %s: %s", path, strerror(errno));
 
        if (S_ISBLK(statbuf.st_mode)) {
                /* check IO limits:
@@ -714,17 +514,9 @@ unsigned get_blocksize(const char *path)
                 * we want to use logical_block_size.
                 */
                unsigned int logical_block_size;
-               int fd = open(path, O_RDONLY);
+               if (ioctl(fd, BLKSSZGET, &logical_block_size))
+                       die("ioctl(%s, BLKSSZGET) failed: %m", path);
 
-               if (fd < 0) {
-                       fprintf(stderr, "open(%s) failed: %m\n", path);
-                       exit(EXIT_FAILURE);
-               }
-               if (ioctl(fd, BLKSSZGET, &logical_block_size)) {
-                       fprintf(stderr, "ioctl(%s, BLKSSZGET) failed: %m\n", path);
-                       exit(EXIT_FAILURE);
-               }
-               close(fd);
                return logical_block_size / 512;
 
        }
@@ -738,10 +530,8 @@ long strtoul_or_die(const char *p, size_t max, const char *msg)
 {
        errno = 0;
        long v = strtol(p, NULL, 10);
-       if (errno || v < 0 || v >= max) {
-               fprintf(stderr, "Invalid %s %zi\n", msg, v);
-               exit(EXIT_FAILURE);
-       }
+       if (errno || v < 0 || v >= max)
+               die("Invalid %s %zi", msg, v);
 
        return v;
 }
@@ -771,8 +561,7 @@ static void show_super_common(struct cache_sb *sb, bool force_csum)
                printf("ok\n");
        } else {
                printf("bad magic\n");
-               fprintf(stderr, "Invalid superblock (bad magic)\n");
-               exit(2);
+               die("Invalid superblock (bad magic)");
        }
 
        printf("sb.first_sector\t\t%ju", (uint64_t) sb->offset);
@@ -780,8 +569,7 @@ static void show_super_common(struct cache_sb *sb, bool force_csum)
                printf(" [match]\n");
        } else {
                printf(" [expected %ds]\n", SB_SECTOR);
-               fprintf(stderr, "Invalid superblock (bad sector)\n");
-               exit(2);
+               die("Invalid superblock (bad sector)");
        }
 
        printf("sb.csum\t\t\t%ju", (uint64_t) sb->csum);
@@ -793,10 +581,8 @@ static void show_super_common(struct cache_sb *sb, bool force_csum)
                printf(" [match]\n");
        } else {
                printf(" [expected %" PRIX64 "]\n", expected_csum);
-               if (force_csum) {
-                       fprintf(stderr, "Corrupt superblock (bad csum)\n");
-                       exit(2);
-               }
+               if (force_csum)
+                       die("Corrupt superblock (bad csum)");
        }
 
        printf("sb.version\t\t%ju", (uint64_t) sb->version);
@@ -835,6 +621,10 @@ static void show_super_common(struct cache_sb *sb, bool force_csum)
 
        uuid_unparse(sb->user_uuid.b, uuid);
        printf("cset.uuid\t\t%s\n", uuid);
+
+       uuid_unparse(sb->set_uuid.b, uuid);
+       printf("internal.uuid\t%s\n", uuid);
+
 }
 
 void show_super_backingdev(struct cache_sb *sb, bool force_csum)
@@ -860,9 +650,13 @@ void show_super_backingdev(struct cache_sb *sb, bool force_csum)
 void show_super_cache(struct cache_sb *sb, bool force_csum)
 {
        struct cache_member *m = sb->members + sb->nr_this_dev;
+       char uuid[16];
 
        show_super_common(sb, force_csum);
 
+       uuid_unparse(m->uuid.b, uuid);
+       printf("dev.cache.uuid\t%s\n", uuid);
+
        printf("dev.sectors_per_block\t%u\n"
               "dev.sectors_per_bucket\t%u\n",
               sb->block_size,
@@ -887,8 +681,6 @@ void show_super_cache(struct cache_sb *sb, bool force_csum)
        printf("cache.tier\t%llu\n",            CACHE_TIER(m));
 
        printf("cache.replication_set\t%llu\n", CACHE_REPLICATION_SET(m));
-       printf("cache.cur_meta_replicas\t%llu\n", REPLICATION_SET_CUR_META_REPLICAS(m));
-       printf("cache.cur_data_replicas\t%llu\n", REPLICATION_SET_CUR_DATA_REPLICAS(m));
 
        printf("cache.has_metadata\t%llu\n",    CACHE_HAS_METADATA(m));
        printf("cache.has_data\t%llu\n",        CACHE_HAS_DATA(m));
@@ -1000,55 +792,6 @@ char *dev_name(const char *ugly_path) {
        return strdup(buf);
 }
 
-static void list_cacheset_devs(char *cset_dir, char *cset_name, bool parse_dev_name)
-{
-       DIR *cachedir, *dir;
-       struct stat cache_stat;
-       char entry[MAX_PATH];
-       struct dirent *ent;
-       snprintf(entry, MAX_PATH, "%s/%s", cset_dir, cset_name);
-
-       if((dir = opendir(entry)) != NULL) {
-               while((ent = readdir(dir)) != NULL) {
-                       char buf[MAX_PATH];
-                       int len;
-                       char *tmp;
-
-                       /*
-                        * We are looking for all cache# directories
-                        * do a strlen < 9 to skip over other entries
-                        * that also start with "cache"
-                        */
-                       if(strncmp(ent->d_name, "cache", 5) ||
-                                       !(strlen(ent->d_name) < 9))
-                               continue;
-
-                       snprintf(entry, MAX_PATH, "%s/%s/%s",
-                                       cset_dir,
-                                       cset_name,
-                                       ent->d_name);
-
-                       if((cachedir = opendir(entry)) == NULL)
-                               continue;
-
-                       if(stat(entry, &cache_stat))
-                               continue;
-
-                       if((len = readlink(entry, buf, sizeof(buf) - 1)) !=
-                                       -1) {
-                               buf[len] = '\0';
-                               if(parse_dev_name) {
-                                       tmp = dev_name(buf);
-                                       printf("/dev%s\n", tmp);
-                                       free(tmp);
-                               } else {
-                                       printf("\t%s\n", buf);
-                               }
-                       }
-               }
-       }
-}
-
 char *find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uuid)
 {
        /* Do a query-dev --uuid only to get the uuid
@@ -1121,373 +864,21 @@ char *find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uu
        return err;
 }
 
-char *list_cachesets(char *cset_dir, bool list_devs)
+int bcachectl_open(void)
 {
-       struct dirent *ent;
-       DIR *dir;
-       char *err = NULL;
-
-       dir = opendir(cset_dir);
-       if (!dir) {
-               err = "Failed to open cacheset dir";
-               goto err;
-       }
-
-       while ((ent = readdir(dir)) != NULL) {
-               struct stat statbuf;
-               char entry[MAX_PATH];
-
-               if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
-                       continue;
-
-               snprintf(entry, MAX_PATH, "%s/%s", cset_dir, ent->d_name);
-               if(stat(entry, &statbuf) == -1) {
-                       err = "Failed to stat cacheset subdir";
-                       goto err;
-               }
+       int fd = open("/dev/bcache-ctl", O_RDWR);
+       if (fd < 0)
+               die("Can't open bcache device: %s", strerror(errno));
 
-               if (S_ISDIR(statbuf.st_mode)) {
-                       printf("%s\n", ent->d_name);
-
-                       if(list_devs) {
-                               list_cacheset_devs(cset_dir, ent->d_name, true);
-                       }
-               }
-       }
-
-err:
-       closedir(dir);
-       return err;
-}
-
-char *register_bcache(char *const *devs)
-{
-       int ret, bcachefd;
-       char *err = NULL;
-
-       bcachefd = open("/dev/bcache", O_RDWR);
-       if (bcachefd < 0) {
-               err = "Can't open bcache device";
-               goto err;
-       }
-
-       ret = ioctl(bcachefd, BCH_IOCTL_REGISTER, devs);
-       if (ret < 0) {
-               char tmp[64];
-               snprintf(tmp, 64, "ioctl register error: %s\n",
-                               strerror(ret));
-               err = strdup(tmp);
-               goto err;
-       }
-
-err:
-       if (bcachefd)
-               close(bcachefd);
-       return err;
-}
-
-char *unregister_bcache(char *const *devs)
-{
-       int ret, bcachefd;
-       char *err = NULL;
-
-       bcachefd = open("/dev/bcache_extent0", O_RDWR);
-       if (bcachefd < 0) {
-               err = "Can't open bcache device";
-               goto err;
-       }
-
-       ret = ioctl(bcachefd, BCH_IOCTL_STOP);
-       if (ret < 0) {
-               char tmp[64];
-               snprintf(tmp, 64, "ioctl unregister error: %s\n",
-                               strerror(ret));
-               err = strdup(tmp);
-               goto err;
-       }
-
-err:
-       close(bcachefd);
-       return err;
-}
-
-char *add_devices(char *const *devs)
-{
-       int ret, bcachefd;
-       char *err = NULL;
-
-       bcachefd = open("/dev/bcache_extent0", O_RDWR);
-       if (bcachefd < 0) {
-               err = "Can't open bcache device";
-               goto err;
-       }
-
-       struct bch_ioctl_add_disks ia;
-       ia.devs = devs;
-
-       ret = ioctl(bcachefd, BCH_IOCTL_ADD_DISKS, &ia);
-       if (ret < 0) {
-               char tmp[128];
-               snprintf(tmp, 128, "ioctl add disk error: %s\n",
-                               strerror(ret));
-               err = strdup(tmp);
-       }
-
-err:
-       close(bcachefd);
-       return err;
-}
-
-char *remove_device(const char *dev, bool force)
-{
-       int ret, bcachefd;
-       char *err = NULL;
-
-       bcachefd = open("/dev/bcache_extent0", O_RDWR);
-       if (bcachefd < 0) {
-               err = "Can't open bcache device";
-               goto err;
-       }
-
-       struct bch_ioctl_rm_disk ir;
-       ir.dev = dev;
-       ir.force = force ? 1 : 0;
-
-       ret = ioctl(bcachefd, BCH_IOCTL_RM_DISK, &ir);
-       if (ret < 0) {
-               char tmp[128];
-               snprintf(tmp, 128, "ioctl add disk error: %s\n",
-                               strerror(ret));
-               err = strdup(tmp);
-       }
-
-err:
-       close(bcachefd);
-       return err;
-}
-
-char *device_set_failed(const char *dev_uuid) {
-       int ret, bcachefd;
-       char *err = NULL;
-       uuid_le dev;
-       struct bch_ioctl_disk_failed df;
-
-       bcachefd = open("/dev/bcache_extent0", O_RDWR);
-       if (bcachefd < 0) {
-               err = "Can't open bcache device";
-               goto err;
-       }
-
-       uuid_parse(dev_uuid, dev.b);
-       df.dev_uuid = dev;
-
-       ret = ioctl(bcachefd, BCH_IOCTL_SET_DISK_FAILED, &df);
-       if (ret < 0) {
-               char tmp[128];
-               snprintf(tmp, 128, "ioctl set disk failed error %s\n",
-                               strerror(ret));
-               err = strdup(tmp);
-       }
-
-err:
-       close(bcachefd);
-       return err;
-}
-
-char *probe(char *dev, int udev)
-{
-       struct cache_sb sb;
-       char uuid[40];
-       blkid_probe pr;
-       char *err = NULL;
-
-       int fd = open(dev, O_RDONLY);
-       if (fd == -1) {
-               err = "Got file descriptor -1 trying to open dev";
-               goto err;
-       }
-
-       if (!(pr = blkid_new_probe())) {
-               err = "Failed trying to get a blkid for new probe";
-               goto err;
-       }
-
-       if (blkid_probe_set_device(pr, fd, 0, 0)) {
-               err = "Failed blkid probe set device";
-               goto err;
-       }
-
-       /* probe partitions too */
-       if (blkid_probe_enable_partitions(pr, true)) {
-               err = "Enable probe partitions";
-               goto err;
-       }
-
-       /* bail if anything was found
-        * probe-bcache isn't needed once blkid recognizes bcache */
-       if (!blkid_do_probe(pr)) {
-               err = "blkid recognizes bcache";
-               goto err;
-       }
-
-       if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
-               err = "Failed to read superblock";
-               goto err;
-       }
-
-       if (memcmp(&sb.magic, &BCACHE_MAGIC, sizeof(sb.magic))) {
-               err = "Bcache magic incorrect";
-               goto err;
-       }
-
-       uuid_unparse(sb.disk_uuid.b, uuid);
-
-       if (udev)
-               printf("ID_FS_UUID=%s\n"
-                      "ID_FS_UUID_ENC=%s\n"
-                      "ID_FS_TYPE=bcache\n",
-                      uuid, uuid);
-       else
-               printf("%s: UUID=\"\" TYPE=\"bcache\"\n", uuid);
-
-       return 0;
-
-err:
-       return err;
+       return fd;
 }
 
-char *read_stat_dir(DIR *dir, char *stats_dir, char *stat_name, char *ret)
+unsigned nr_args(char *const *args)
 {
-       struct stat statbuf;
-       char entry[MAX_PATH];
-       char *err = NULL;
-
-       snprintf(entry, MAX_PATH, "%s/%s", stats_dir, stat_name);
-       if(stat(entry, &statbuf) == -1) {
-               char tmp[MAX_PATH];
-               snprintf(tmp, MAX_PATH, "Failed to stat %s\n", entry);
-               err = strdup(tmp);
-               goto err;
-       }
-
-       if (S_ISREG(statbuf.st_mode)) {
-               FILE *fp = NULL;
+       unsigned i;
 
-               fp = fopen(entry, "r");
-               if(!fp) {
-                       /* If we can't open the file, this is probably because
-                        * of permissions, just move to the next file */
-                       return NULL;
-               }
+       for (i = 0; args[i]; i++)
+               ;
 
-               while(fgets(ret, MAX_PATH, fp));
-               fclose(fp);
-       }
-err:
-       return err;
-}
-
-char *bcache_get_capacity(const char *cset_dir, const char *capacity_uuid,
-                         bool show_devs)
-{
-       char *err = NULL;
-       char bucket_size_path[MAX_PATH];
-       char nbuckets_path[MAX_PATH];
-       char avail_buckets_path[MAX_PATH];
-       char cache_path[MAX_PATH];
-
-       double bucket_sizes[MAX_DEVS];
-       double nbuckets[MAX_DEVS];
-       double avail_buckets[MAX_DEVS];
-       char *dev_names[MAX_DEVS];
-       int dev_count = 0, i;
-       char intbuf[4];
-       double total_cap = 0, total_free = 0;
-       int precision = 2;
-
-       snprintf(bucket_size_path, MAX_PATH, "%s/%s/%s/%s", cset_dir,
-                       capacity_uuid, "cache0", "bucket_size_bytes");
-       snprintf(nbuckets_path, MAX_PATH, "%s/%s/%s/%s", cset_dir,
-                       capacity_uuid, "cache0", "nbuckets");
-       snprintf(avail_buckets_path, MAX_PATH, "%s/%s/%s/%s", cset_dir,
-                       capacity_uuid, "cache0", "available_buckets");
-       snprintf(cache_path, MAX_PATH, "%s/%s/%s", cset_dir, capacity_uuid,
-                       "cache0");
-
-       while (true) {
-               char buf[MAX_PATH];
-               int len;
-               DIR *cache_dir;
-
-               if((cache_dir = opendir(cache_path)) == NULL)
-                       break;
-
-               err = read_stat_dir(cache_dir, cache_path,
-                               "bucket_size_bytes", buf);
-               if (err)
-                       goto err;
-               else
-                       bucket_sizes[dev_count] = atof(buf);
-
-               err = read_stat_dir(cache_dir, cache_path,
-                               "nbuckets", buf);
-               if (err)
-                       goto err;
-               else
-                       nbuckets[dev_count] = atof(buf);
-
-               err = read_stat_dir(cache_dir, cache_path,
-                               "available_buckets", buf);
-               if (err)
-                       goto err;
-               else
-                       avail_buckets[dev_count] = atof(buf);
-
-               if((len = readlink(cache_path, buf, sizeof(buf) - 1)) != -1) {
-                       buf[len] = '\0';
-                       dev_names[dev_count] = dev_name(buf);
-               }
-
-               snprintf(intbuf, 4, "%d", dev_count);
-
-               /* remove i/stat and append i++/stat */
-               bucket_size_path[strlen(cache_path) - strlen(intbuf)] = 0;
-               nbuckets_path[strlen(cache_path) - strlen(intbuf)] = 0;
-               avail_buckets_path[strlen(cache_path) - strlen(intbuf)] = 0;
-               cache_path[strlen(cache_path) - strlen(intbuf)] = 0;
-
-               dev_count++;
-
-               strcat(cache_path, intbuf);
-               strcat(bucket_size_path, intbuf);
-               strcat(nbuckets_path, intbuf);
-               strcat(avail_buckets_path, intbuf);
-       }
-
-       printf("%-15s%-25s%-25s\n", "Device Name", "Capacity (512 Blocks)", "Free (512 Blocks)");
-
-       if (show_devs) {
-               for (i = 0; i < dev_count; i++) {
-                       printf("%s%-11s%-25.*f%-25.*f\n", "/dev", dev_names[i],
-                               precision,
-                               (bucket_sizes[i] * nbuckets[i]) / 512,
-                               precision,
-                               (bucket_sizes[i] * avail_buckets[i]) / 512);
-               }
-       }
-
-       for (i = 0; i < dev_count; i++) {
-               total_cap += (bucket_sizes[i] * nbuckets[i]) / 512;
-               total_free += (bucket_sizes[i] * avail_buckets[i]) / 512;
-
-       }
-
-       printf("%-15s%-25.*f%-25.*f\n", "Total", precision, total_cap,
-                       precision, total_free);
-
-err:
-       for (i = 0; i < dev_count; i++)
-               if (dev_names[i])
-                       free(dev_names[i]);
-       return err;
+       return i;
 }