diff options
Diffstat (limited to 'libblkid/lib/sysfs.c')
-rw-r--r-- | libblkid/lib/sysfs.c | 1069 |
1 files changed, 1069 insertions, 0 deletions
diff --git a/libblkid/lib/sysfs.c b/libblkid/lib/sysfs.c new file mode 100644 index 000000000..63a90dcbc --- /dev/null +++ b/libblkid/lib/sysfs.c @@ -0,0 +1,1069 @@ +/* + * No copyright is claimed. This code is in the public domain; do with + * it what you wish. + * + * Written by Karel Zak <kzak@redhat.com> + */ +#include <ctype.h> + +#include "c.h" +#include "at.h" +#include "pathnames.h" +#include "sysfs.h" +#include "fileutils.h" +#include "all-io.h" + +char *sysfs_devno_attribute_path(dev_t devno, char *buf, + size_t bufsiz, const char *attr) +{ + int len; + + if (attr) + len = snprintf(buf, bufsiz, _PATH_SYS_DEVBLOCK "/%d:%d/%s", + major(devno), minor(devno), attr); + else + len = snprintf(buf, bufsiz, _PATH_SYS_DEVBLOCK "/%d:%d", + major(devno), minor(devno)); + + return (len < 0 || (size_t) len + 1 > bufsiz) ? NULL : buf; +} + +int sysfs_devno_has_attribute(dev_t devno, const char *attr) +{ + char path[PATH_MAX]; + struct stat info; + + if (!sysfs_devno_attribute_path(devno, path, sizeof(path), attr)) + return 0; + if (stat(path, &info) == 0) + return 1; + return 0; +} + +char *sysfs_devno_path(dev_t devno, char *buf, size_t bufsiz) +{ + return sysfs_devno_attribute_path(devno, buf, bufsiz, NULL); +} + +dev_t sysfs_devname_to_devno(const char *name, const char *parent) +{ + char buf[PATH_MAX], *path = NULL; + dev_t dev = 0; + + if (strncmp("/dev/", name, 5) == 0) { + /* + * Read from /dev + */ + struct stat st; + + if (stat(name, &st) == 0) + dev = st.st_rdev; + else + name += 5; /* unaccesible, or not node in /dev */ + } + + if (!dev && parent && strncmp("dm-", name, 3)) { + /* + * Create path to /sys/block/<parent>/<name>/dev + */ + int len = snprintf(buf, sizeof(buf), + _PATH_SYS_BLOCK "/%s/%s/dev", parent, name); + if (len < 0 || (size_t) len + 1 > sizeof(buf)) + return 0; + path = buf; + + } else if (!dev) { + /* + * Create path to /sys/block/<name>/dev + */ + int len = snprintf(buf, sizeof(buf), + _PATH_SYS_BLOCK "/%s/dev", name); + if (len < 0 || (size_t) len + 1 > sizeof(buf)) + return 0; + path = buf; + } + + if (path) { + /* + * read devno from sysfs + */ + FILE *f; + int maj = 0, min = 0; + + f = fopen(path, "r" UL_CLOEXECSTR); + if (!f) + return 0; + + if (fscanf(f, "%d:%d", &maj, &min) == 2) + dev = makedev(maj, min); + fclose(f); + } + return dev; +} + +/* + * Returns devname (e.g. "/dev/sda1") for the given devno. + * + * Note that the @buf has to be large enough to store /sys/dev/block/<maj:min> + * symlinks. + * + * Please, use more robust blkid_devno_to_devname() in your applications. + */ +char *sysfs_devno_to_devpath(dev_t devno, char *buf, size_t bufsiz) +{ + struct sysfs_cxt cxt; + char *name; + size_t sz; + struct stat st; + + if (sysfs_init(&cxt, devno, NULL)) + return NULL; + + name = sysfs_get_devname(&cxt, buf, bufsiz); + sysfs_deinit(&cxt); + + if (!name) + return NULL; + + sz = strlen(name); + + if (sz + sizeof("/dev/") > bufsiz) + return NULL; + + /* create the final "/dev/<name>" string */ + memmove(buf + 5, name, sz + 1); + memcpy(buf, "/dev/", 5); + + if (!stat(buf, &st) && S_ISBLK(st.st_mode) && st.st_rdev == devno) + return buf; + + return NULL; +} + +int sysfs_init(struct sysfs_cxt *cxt, dev_t devno, struct sysfs_cxt *parent) +{ + char path[PATH_MAX]; + int fd, rc; + + memset(cxt, 0, sizeof(*cxt)); + cxt->dir_fd = -1; + + if (!sysfs_devno_path(devno, path, sizeof(path))) + goto err; + + fd = open(path, O_RDONLY|O_CLOEXEC); + if (fd < 0) + goto err; + cxt->dir_fd = fd; + + cxt->dir_path = strdup(path); + if (!cxt->dir_path) + goto err; + cxt->devno = devno; + cxt->parent = parent; + return 0; +err: + rc = errno > 0 ? -errno : -1; + sysfs_deinit(cxt); + return rc; +} + +void sysfs_deinit(struct sysfs_cxt *cxt) +{ + if (!cxt) + return; + + if (cxt->dir_fd >= 0) + close(cxt->dir_fd); + free(cxt->dir_path); + + memset(cxt, 0, sizeof(*cxt)); + + cxt->dir_fd = -1; +} + +int sysfs_stat(struct sysfs_cxt *cxt, const char *attr, struct stat *st) +{ + int rc = fstat_at(cxt->dir_fd, cxt->dir_path, attr, st, 0); + + if (rc != 0 && errno == ENOENT && + strncmp(attr, "queue/", 6) == 0 && cxt->parent) { + + /* Exception for "queue/<attr>". These attributes are available + * for parental devices only + */ + return fstat_at(cxt->parent->dir_fd, + cxt->parent->dir_path, attr, st, 0); + } + return rc; +} + +int sysfs_has_attribute(struct sysfs_cxt *cxt, const char *attr) +{ + struct stat st; + + return sysfs_stat(cxt, attr, &st) == 0; +} + +static int sysfs_open(struct sysfs_cxt *cxt, const char *attr, int flags) +{ + int fd = open_at(cxt->dir_fd, cxt->dir_path, attr, flags); + + if (fd == -1 && errno == ENOENT && + strncmp(attr, "queue/", 6) == 0 && cxt->parent) { + + /* Exception for "queue/<attr>". These attributes are available + * for parental devices only + */ + fd = open_at(cxt->parent->dir_fd, cxt->dir_path, attr, flags); + } + return fd; +} + +ssize_t sysfs_readlink(struct sysfs_cxt *cxt, const char *attr, + char *buf, size_t bufsiz) +{ + if (!cxt->dir_path) + return -1; + + if (attr) + return readlink_at(cxt->dir_fd, cxt->dir_path, attr, buf, bufsiz); + + /* read /sys/dev/block/<maj:min> link */ + return readlink(cxt->dir_path, buf, bufsiz); +} + +DIR *sysfs_opendir(struct sysfs_cxt *cxt, const char *attr) +{ + DIR *dir; + int fd = -1; + + if (attr) + fd = sysfs_open(cxt, attr, O_RDONLY|O_CLOEXEC); + + else if (cxt->dir_fd >= 0) + /* request to open root of device in sysfs (/sys/block/<dev>) + * -- we cannot use cxt->sysfs_fd directly, because closedir() + * will close this our persistent file descriptor. + */ + fd = dup(cxt->dir_fd); + + if (fd < 0) + return NULL; + + dir = fdopendir(fd); + if (!dir) { + close(fd); + return NULL; + } + if (!attr) + rewinddir(dir); + return dir; +} + + +static FILE *sysfs_fopen(struct sysfs_cxt *cxt, const char *attr) +{ + int fd = sysfs_open(cxt, attr, O_RDONLY|O_CLOEXEC); + + return fd < 0 ? NULL : fdopen(fd, "r" UL_CLOEXECSTR); +} + + +static struct dirent *xreaddir(DIR *dp) +{ + struct dirent *d; + + while ((d = readdir(dp))) { + if (!strcmp(d->d_name, ".") || + !strcmp(d->d_name, "..")) + continue; + + /* blacklist here? */ + break; + } + return d; +} + +int sysfs_is_partition_dirent(DIR *dir, struct dirent *d, const char *parent_name) +{ + char path[256]; + +#ifdef _DIRENT_HAVE_D_TYPE + if (d->d_type != DT_DIR && + d->d_type != DT_LNK && + d->d_type != DT_UNKNOWN) + return 0; +#endif + if (parent_name) { + const char *p = parent_name; + size_t len; + + /* /dev/sda --> "sda" */ + if (*parent_name == '/') { + p = strrchr(parent_name, '/'); + if (!p) + return 0; + p++; + } + + len = strlen(p); + if (strlen(d->d_name) <= len) + return 0; + + /* partitions subdir name is + * "<parent>[:digit:]" or "<parent>p[:digit:]" + */ + return strncmp(p, d->d_name, len) == 0 && + ((*(d->d_name + len) == 'p' && isdigit(*(d->d_name + len + 1))) + || isdigit(*(d->d_name + len))); + } + + /* Cannot use /partition file, not supported on old sysfs */ + snprintf(path, sizeof(path), "%s/start", d->d_name); + + return faccessat(dirfd(dir), path, R_OK, 0) == 0; +} + +/* + * Converts @partno (partition number) to devno of the partition. + * The @cxt handles wholedisk device. + * + * Note that this code does not expect any special format of the + * partitions devnames. + */ +dev_t sysfs_partno_to_devno(struct sysfs_cxt *cxt, int partno) +{ + DIR *dir; + struct dirent *d; + char path[256]; + dev_t devno = 0; + + dir = sysfs_opendir(cxt, NULL); + if (!dir) + return 0; + + while ((d = xreaddir(dir))) { + int n, maj, min; + + if (!sysfs_is_partition_dirent(dir, d, NULL)) + continue; + + snprintf(path, sizeof(path), "%s/partition", d->d_name); + if (sysfs_read_int(cxt, path, &n)) + continue; + + if (n == partno) { + snprintf(path, sizeof(path), "%s/dev", d->d_name); + if (sysfs_scanf(cxt, path, "%d:%d", &maj, &min) == 2) + devno = makedev(maj, min); + break; + } + } + + closedir(dir); + return devno; +} + + +int sysfs_scanf(struct sysfs_cxt *cxt, const char *attr, const char *fmt, ...) +{ + FILE *f = sysfs_fopen(cxt, attr); + va_list ap; + int rc; + + if (!f) + return -EINVAL; + va_start(ap, fmt); + rc = vfscanf(f, fmt, ap); + va_end(ap); + + fclose(f); + return rc; +} + + +int sysfs_read_s64(struct sysfs_cxt *cxt, const char *attr, int64_t *res) +{ + int64_t x = 0; + + if (sysfs_scanf(cxt, attr, "%"SCNd64, &x) == 1) { + if (res) + *res = x; + return 0; + } + return -1; +} + +int sysfs_read_u64(struct sysfs_cxt *cxt, const char *attr, uint64_t *res) +{ + uint64_t x = 0; + + if (sysfs_scanf(cxt, attr, "%"SCNu64, &x) == 1) { + if (res) + *res = x; + return 0; + } + return -1; +} + +int sysfs_read_int(struct sysfs_cxt *cxt, const char *attr, int *res) +{ + int x = 0; + + if (sysfs_scanf(cxt, attr, "%d", &x) == 1) { + if (res) + *res = x; + return 0; + } + return -1; +} + +int sysfs_write_string(struct sysfs_cxt *cxt, const char *attr, const char *str) +{ + int fd = sysfs_open(cxt, attr, O_WRONLY|O_CLOEXEC); + int rc, errsv; + + if (fd < 0) + return -errno; + rc = write_all(fd, str, strlen(str)); + + errsv = errno; + close(fd); + errno = errsv; + return rc; +} + +int sysfs_write_u64(struct sysfs_cxt *cxt, const char *attr, uint64_t num) +{ + char buf[sizeof(stringify_value(ULLONG_MAX))]; + int fd, rc = 0, len, errsv; + + fd = sysfs_open(cxt, attr, O_WRONLY|O_CLOEXEC); + if (fd < 0) + return -errno; + + len = snprintf(buf, sizeof(buf), "%ju", num); + if (len < 0 || (size_t) len + 1 > sizeof(buf)) + rc = -errno; + else + rc = write_all(fd, buf, len); + + errsv = errno; + close(fd); + errno = errsv; + return rc; +} + +char *sysfs_strdup(struct sysfs_cxt *cxt, const char *attr) +{ + char buf[1024]; + return sysfs_scanf(cxt, attr, "%1023[^\n]", buf) == 1 ? + strdup(buf) : NULL; +} + +int sysfs_count_dirents(struct sysfs_cxt *cxt, const char *attr) +{ + DIR *dir; + int r = 0; + + if (!(dir = sysfs_opendir(cxt, attr))) + return 0; + + while (xreaddir(dir)) r++; + + closedir(dir); + return r; +} + +int sysfs_count_partitions(struct sysfs_cxt *cxt, const char *devname) +{ + DIR *dir; + struct dirent *d; + int r = 0; + + if (!(dir = sysfs_opendir(cxt, NULL))) + return 0; + + while ((d = xreaddir(dir))) { + if (sysfs_is_partition_dirent(dir, d, devname)) + r++; + } + + closedir(dir); + return r; +} + +/* + * Returns slave name if there is only one slave, otherwise returns NULL. + * The result should be deallocated by free(). + */ +char *sysfs_get_slave(struct sysfs_cxt *cxt) +{ + DIR *dir; + struct dirent *d; + char *name = NULL; + + if (!(dir = sysfs_opendir(cxt, "slaves"))) + return NULL; + + while ((d = xreaddir(dir))) { + if (name) + goto err; /* more slaves */ + + name = strdup(d->d_name); + } + + closedir(dir); + return name; +err: + free(name); + closedir(dir); + return NULL; +} + +/* + * Note that the @buf has to be large enough to store /sys/dev/block/<maj:min> + * symlinks. + */ +char *sysfs_get_devname(struct sysfs_cxt *cxt, char *buf, size_t bufsiz) +{ + char *name = NULL; + ssize_t sz; + + sz = sysfs_readlink(cxt, NULL, buf, bufsiz - 1); + if (sz < 0) + return NULL; + + buf[sz] = '\0'; + name = strrchr(buf, '/'); + if (!name) + return NULL; + + name++; + sz = strlen(name); + + memmove(buf, name, sz + 1); + return buf; +} + +#define SUBSYSTEM_LINKNAME "/subsystem" + +/* + * For example: + * + * chain: /sys/dev/block/../../devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/ \ + * 1-1.2:1.0/host65/target65:0:0/65:0:0:0/block/sdb + * + * The function check if <chain>/subsystem symlink exists, if yes then returns + * basename of the readlink result, and remove the last subdirectory from the + * <chain> path. + */ +static char *get_subsystem(char *chain, char *buf, size_t bufsz) +{ + size_t len; + char *p; + + if (!chain || !*chain) + return NULL; + + len = strlen(chain); + if (len + sizeof(SUBSYSTEM_LINKNAME) > PATH_MAX) + return NULL; + + do { + ssize_t sz; + + /* append "/subsystem" to the path */ + memcpy(chain + len, SUBSYSTEM_LINKNAME, sizeof(SUBSYSTEM_LINKNAME)); + + /* try if subsystem symlink exists */ + sz = readlink(chain, buf, bufsz - 1); + + /* remove last subsystem from chain */ + chain[len] = '\0'; + p = strrchr(chain, '/'); + if (p) { + *p = '\0'; + len = p - chain; + } + + if (sz > 0) { + /* we found symlink to subsystem, return basename */ + buf[sz] = '\0'; + return basename(buf); + } + + } while (p); + + return NULL; +} + +/* + * Returns complete path to the device, the patch contains all all sybsystems + * used for the device. + */ +char *sysfs_get_devchain(struct sysfs_cxt *cxt, char *buf, size_t bufsz) +{ + /* read /sys/dev/block/<maj>:<min> symlink */ + size_t sz = sysfs_readlink(cxt, NULL, buf, bufsz); + if (sz <= 0 || sz + sizeof(_PATH_SYS_DEVBLOCK "/") > bufsz) + return NULL; + + buf[sz++] = '\0'; + + /* create absolute patch from the link */ + memmove(buf + sizeof(_PATH_SYS_DEVBLOCK "/") - 1, buf, sz); + memcpy(buf, _PATH_SYS_DEVBLOCK "/", sizeof(_PATH_SYS_DEVBLOCK "/") - 1); + + return buf; +} + +/* + * The @subsys returns the next subsystem in the chain. Function modifies + * @devchain string. + * + * Returns: 0 in success, <0 on error, 1 on end of chain + */ +int sysfs_next_subsystem(struct sysfs_cxt *cxt __attribute__((unused)), + char *devchain, char **subsys) +{ + char subbuf[PATH_MAX]; + char *sub; + + if (!subsys || !devchain) + return -EINVAL; + + while ((sub = get_subsystem(devchain, subbuf, sizeof(subbuf)))) { + *subsys = strdup(sub); + if (!*subsys) + return -ENOMEM; + return 0; + } + + return 1; +} + + +static int is_hotpluggable_subsystem(const char *name) +{ + static const char * const hotplug_subsystems[] = { + "usb", + "ieee1394", + "pcmcia", + "mmc", + "ccw" + }; + size_t i; + + for (i = 0; i < ARRAY_SIZE(hotplug_subsystems); i++) + if (strcmp(name, hotplug_subsystems[i]) == 0) + return 1; + + return 0; +} + +int sysfs_is_hotpluggable(struct sysfs_cxt *cxt) +{ + char buf[PATH_MAX], *chain, *sub; + int rc = 0; + + + /* check /sys/dev/block/<maj>:<min>/removable attribute */ + if (sysfs_read_int(cxt, "removable", &rc) == 0 && rc == 1) + return 1; + + chain = sysfs_get_devchain(cxt, buf, sizeof(buf)); + + while (chain && sysfs_next_subsystem(cxt, chain, &sub) == 0) { + rc = is_hotpluggable_subsystem(sub); + if (rc) { + free(sub); + break; + } + free(sub); + } + + return rc; +} + +static int get_dm_wholedisk(struct sysfs_cxt *cxt, char *diskname, + size_t len, dev_t *diskdevno) +{ + int rc = 0; + char *name; + + /* Note, sysfs_get_slave() returns the first slave only, + * if there is more slaves, then return NULL + */ + name = sysfs_get_slave(cxt); + if (!name) + return -1; + + if (diskname && len) { + strncpy(diskname, name, len); + diskname[len - 1] = '\0'; + } + + if (diskdevno) { + *diskdevno = sysfs_devname_to_devno(name, NULL); + if (!*diskdevno) + rc = -1; + } + + free(name); + return rc; +} + +/* + * Returns by @diskdevno whole disk device devno and (optionaly) by + * @diskname the whole disk device name. + */ +int sysfs_devno_to_wholedisk(dev_t dev, char *diskname, + size_t len, dev_t *diskdevno) +{ + struct sysfs_cxt cxt; + int is_part = 0; + + if (!dev || sysfs_init(&cxt, dev, NULL) != 0) + return -1; + + is_part = sysfs_has_attribute(&cxt, "partition"); + if (!is_part) { + /* + * Extra case for partitions mapped by device-mapper. + * + * All regualar partitions (added by BLKPG ioctl or kernel PT + * parser) have the /sys/.../partition file. The partitions + * mapped by DM don't have such file, but they have "part" + * prefix in DM UUID. + */ + char *uuid = sysfs_strdup(&cxt, "dm/uuid"); + char *tmp = uuid; + char *prefix = uuid ? strsep(&tmp, "-") : NULL; + + if (prefix && strncasecmp(prefix, "part", 4) == 0) + is_part = 1; + free(uuid); + + if (is_part && + get_dm_wholedisk(&cxt, diskname, len, diskdevno) == 0) + /* + * partitioned device, mapped by DM + */ + goto done; + + is_part = 0; + } + + if (!is_part) { + /* + * unpartitioned device + */ + if (diskname && len) { + if (!sysfs_get_devname(&cxt, diskname, len)) + goto err; + } + if (diskdevno) + *diskdevno = dev; + + } else { + /* + * partitioned device + * - readlink /sys/dev/block/8:1 = ../../block/sda/sda1 + * - dirname ../../block/sda/sda1 = ../../block/sda + * - basename ../../block/sda = sda + */ + char linkpath[PATH_MAX]; + char *name; + int linklen; + + linklen = sysfs_readlink(&cxt, NULL, + linkpath, sizeof(linkpath) - 1); + if (linklen < 0) + goto err; + linkpath[linklen] = '\0'; + + stripoff_last_component(linkpath); /* dirname */ + name = stripoff_last_component(linkpath); /* basename */ + if (!name) + goto err; + + if (diskname && len) { + strncpy(diskname, name, len); + diskname[len - 1] = '\0'; + } + + if (diskdevno) { + *diskdevno = sysfs_devname_to_devno(name, NULL); + if (!*diskdevno) + goto err; + } + } + +done: + sysfs_deinit(&cxt); + return 0; +err: + sysfs_deinit(&cxt); + return -1; +} + +/* + * Returns 1 if the device is private LVM device. + */ +int sysfs_devno_is_lvm_private(dev_t devno) +{ + struct sysfs_cxt cxt = UL_SYSFSCXT_EMPTY; + char *uuid = NULL; + int rc = 0; + + if (sysfs_init(&cxt, devno, NULL) != 0) + return 0; + + uuid = sysfs_strdup(&cxt, "dm/uuid"); + + /* Private LVM devices use "LVM-<uuid>-<name>" uuid format (important + * is the "LVM" prefix and "-<name>" postfix). + */ + if (uuid && strncmp(uuid, "LVM-", 4) == 0) { + char *p = strrchr(uuid + 4, '-'); + + if (p && *(p + 1)) + rc = 1; + } + + sysfs_deinit(&cxt); + free(uuid); + return rc; +} + +/* + * Return 0 or 1, or < 0 in case of error + */ +int sysfs_devno_is_wholedisk(dev_t devno) +{ + dev_t disk; + + if (sysfs_devno_to_wholedisk(devno, NULL, 0, &disk) != 0) + return -1; + + return devno == disk; +} + + +int sysfs_scsi_get_hctl(struct sysfs_cxt *cxt, int *h, int *c, int *t, int *l) +{ + char buf[PATH_MAX], *hctl; + ssize_t len; + + if (!cxt) + return -EINVAL; + if (cxt->has_hctl) + goto done; + + len = sysfs_readlink(cxt, "device", buf, sizeof(buf) - 1); + if (len < 0) + return len; + + buf[len] = '\0'; + hctl = strrchr(buf, '/'); + if (!hctl) + return -1; + hctl++; + + if (sscanf(hctl, "%u:%u:%u:%u", &cxt->scsi_host, &cxt->scsi_channel, + &cxt->scsi_target, &cxt->scsi_lun) != 4) + return -1; + + cxt->has_hctl = 1; +done: + if (h) + *h = cxt->scsi_host; + if (c) + *c = cxt->scsi_channel; + if (t) + *t = cxt->scsi_target; + if (l) + *l = cxt->scsi_lun; + return 0; +} + + +static char *sysfs_scsi_host_attribute_path(struct sysfs_cxt *cxt, + const char *type, char *buf, size_t bufsz, const char *attr) +{ + int len; + int host; + + if (sysfs_scsi_get_hctl(cxt, &host, NULL, NULL, NULL)) + return NULL; + + if (attr) + len = snprintf(buf, bufsz, _PATH_SYS_CLASS "/%s_host/host%d/%s", + type, host, attr); + else + len = snprintf(buf, bufsz, _PATH_SYS_CLASS "/%s_host/host%d", + type, host); + + return (len < 0 || (size_t) len + 1 > bufsz) ? NULL : buf; +} + +char *sysfs_scsi_host_strdup_attribute(struct sysfs_cxt *cxt, + const char *type, const char *attr) +{ + char buf[1024]; + int rc; + FILE *f; + + if (!attr || !type || + !sysfs_scsi_host_attribute_path(cxt, type, buf, sizeof(buf), attr)) + return NULL; + + if (!(f = fopen(buf, "r" UL_CLOEXECSTR))) + return NULL; + + rc = fscanf(f, "%1023[^\n]", buf); + fclose(f); + + return rc == 1 ? strdup(buf) : NULL; +} + +int sysfs_scsi_host_is(struct sysfs_cxt *cxt, const char *type) +{ + char buf[PATH_MAX]; + struct stat st; + + if (!type || !sysfs_scsi_host_attribute_path(cxt, type, + buf, sizeof(buf), NULL)) + return 0; + + return stat(buf, &st) == 0 && S_ISDIR(st.st_mode); +} + +static char *sysfs_scsi_attribute_path(struct sysfs_cxt *cxt, + char *buf, size_t bufsz, const char *attr) +{ + int len, h, c, t, l; + + if (sysfs_scsi_get_hctl(cxt, &h, &c, &t, &l) != 0) + return NULL; + + if (attr) + len = snprintf(buf, bufsz, _PATH_SYS_SCSI "/devices/%d:%d:%d:%d/%s", + h,c,t,l, attr); + else + len = snprintf(buf, bufsz, _PATH_SYS_SCSI "/devices/%d:%d:%d:%d", + h,c,t,l); + return (len < 0 || (size_t) len + 1 > bufsz) ? NULL : buf; +} + +int sysfs_scsi_has_attribute(struct sysfs_cxt *cxt, const char *attr) +{ + char path[PATH_MAX]; + struct stat st; + + if (!sysfs_scsi_attribute_path(cxt, path, sizeof(path), attr)) + return 0; + + return stat(path, &st) == 0; +} + +int sysfs_scsi_path_contains(struct sysfs_cxt *cxt, const char *pattern) +{ + char path[PATH_MAX], linkc[PATH_MAX]; + struct stat st; + ssize_t len; + + if (!sysfs_scsi_attribute_path(cxt, path, sizeof(path), NULL)) + return 0; + + if (stat(path, &st) != 0) + return 0; + + len = readlink(path, linkc, sizeof(linkc) - 1); + if (len < 0) + return 0; + + linkc[len] = '\0'; + return strstr(linkc, pattern) != NULL; +} + +#ifdef TEST_PROGRAM_SYSFS +#include <errno.h> +#include <err.h> +#include <stdlib.h> + +int main(int argc, char *argv[]) +{ + struct sysfs_cxt cxt = UL_SYSFSCXT_EMPTY; + char *devname; + dev_t devno; + char path[PATH_MAX], *sub, *chain; + int i, is_part; + uint64_t u64; + ssize_t len; + + if (argc != 2) + errx(EXIT_FAILURE, "usage: %s <devname>", argv[0]); + + devname = argv[1]; + devno = sysfs_devname_to_devno(devname, NULL); + + if (!devno) + err(EXIT_FAILURE, "failed to read devno"); + + is_part = sysfs_devno_has_attribute(devno, "partition"); + + printf("NAME: %s\n", devname); + printf("DEVNO: %u (%d:%d)\n", (unsigned int) devno, major(devno), minor(devno)); + printf("DEVNOPATH: %s\n", sysfs_devno_path(devno, path, sizeof(path))); + printf("DEVPATH: %s\n", sysfs_devno_to_devpath(devno, path, sizeof(path))); + printf("PARTITION: %s\n", is_part ? "YES" : "NOT"); + + if (sysfs_init(&cxt, devno, NULL)) + return EXIT_FAILURE; + + len = sysfs_readlink(&cxt, NULL, path, sizeof(path) - 1); + if (len > 0) { + path[len] = '\0'; + printf("DEVNOLINK: %s\n", path); + } + + if (!is_part) { + printf("First 5 partitions:\n"); + for (i = 1; i <= 5; i++) { + dev_t dev = sysfs_partno_to_devno(&cxt, i); + if (dev) + printf("\t#%d %d:%d\n", i, major(dev), minor(dev)); + } + } + + printf("SLAVES: %d\n", sysfs_count_dirents(&cxt, "slaves")); + + if (sysfs_read_u64(&cxt, "size", &u64)) + printf("read SIZE failed\n"); + else + printf("SIZE: %jd\n", u64); + + if (sysfs_read_int(&cxt, "queue/hw_sector_size", &i)) + printf("read SECTOR failed\n"); + else + printf("SECTOR: %d\n", i); + + printf("DEVNAME: %s\n", sysfs_get_devname(&cxt, path, sizeof(path))); + printf("HOTPLUG: %s\n", sysfs_is_hotpluggable(&cxt) ? "yes" : "no"); + + chain = sysfs_get_devchain(&cxt, path, sizeof(path)); + printf("SUBSUSTEMS:\n"); + + while (chain && sysfs_next_subsystem(&cxt, chain, &sub) == 0) { + printf("\t%s\n", sub); + free(sub); + } + + + sysfs_deinit(&cxt); + return EXIT_SUCCESS; +} +#endif |