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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 19:10:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-14 19:10:49 +0000
commitcfe5e3905201349e9cf3f95d52ff4bd100bde37d (patch)
treed0baf160cbee3195249d095f85e52d20c21acf02 /lib/sysfs.c
parentInitial commit. (diff)
downloadutil-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.tar.xz
util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.zip
Adding upstream version 2.39.3.upstream/2.39.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/sysfs.c')
-rw-r--r--lib/sysfs.c1254
1 files changed, 1254 insertions, 0 deletions
diff --git a/lib/sysfs.c b/lib/sysfs.c
new file mode 100644
index 0000000..dfacf4a
--- /dev/null
+++ b/lib/sysfs.c
@@ -0,0 +1,1254 @@
+/*
+ * No copyright is claimed. This code is in the public domain; do with
+ * it what you wish.
+ *
+ * Copyright (C) 2011 Karel Zak <kzak@redhat.com>
+ */
+#include <ctype.h>
+#include <libgen.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "c.h"
+#include "pathnames.h"
+#include "sysfs.h"
+#include "fileutils.h"
+#include "all-io.h"
+#include "debug.h"
+#include "strutils.h"
+#include "buffer.h"
+
+static void sysfs_blkdev_deinit_path(struct path_cxt *pc);
+static int sysfs_blkdev_enoent_redirect(struct path_cxt *pc, const char *path, int *dirfd);
+
+/*
+ * Debug stuff (based on include/debug.h)
+ */
+static UL_DEBUG_DEFINE_MASK(ulsysfs);
+UL_DEBUG_DEFINE_MASKNAMES(ulsysfs) = UL_DEBUG_EMPTY_MASKNAMES;
+
+#define ULSYSFS_DEBUG_INIT (1 << 1)
+#define ULSYSFS_DEBUG_CXT (1 << 2)
+
+#define DBG(m, x) __UL_DBG(ulsysfs, ULSYSFS_DEBUG_, m, x)
+#define ON_DBG(m, x) __UL_DBG_CALL(ulsysfs, ULSYSFS_DEBUG_, m, x)
+
+#define UL_DEBUG_CURRENT_MASK UL_DEBUG_MASK(ulsysfs)
+#include "debugobj.h"
+
+void ul_sysfs_init_debug(void)
+{
+ if (ulsysfs_debug_mask)
+ return;
+ __UL_INIT_DEBUG_FROM_ENV(ulsysfs, ULSYSFS_DEBUG_, 0, ULSYSFS_DEBUG);
+}
+
+struct path_cxt *ul_new_sysfs_path(dev_t devno, struct path_cxt *parent, const char *prefix)
+{
+ struct path_cxt *pc = ul_new_path(NULL);
+
+ if (!pc)
+ return NULL;
+ if (prefix)
+ ul_path_set_prefix(pc, prefix);
+
+ if (sysfs_blkdev_init_path(pc, devno, parent) != 0) {
+ ul_unref_path(pc);
+ return NULL;
+ }
+
+ DBG(CXT, ul_debugobj(pc, "alloc"));
+ return pc;
+}
+
+/*
+ * sysfs_blkdev_* is sysfs extension to ul_path_* API for block devices.
+ *
+ * The function is possible to call in loop and without sysfs_blkdev_deinit_path().
+ * The sysfs_blkdev_deinit_path() is automatically called by ul_unref_path().
+ *
+ */
+int sysfs_blkdev_init_path(struct path_cxt *pc, dev_t devno, struct path_cxt *parent)
+{
+ struct sysfs_blkdev *blk;
+ int rc;
+ char buf[sizeof(_PATH_SYS_DEVBLOCK)
+ + sizeof(stringify_value(UINT32_MAX)) * 2
+ + 3];
+
+ /* define path to devno stuff */
+ snprintf(buf, sizeof(buf), _PATH_SYS_DEVBLOCK "/%d:%d", major(devno), minor(devno));
+ rc = ul_path_set_dir(pc, buf);
+ if (rc)
+ return rc;
+
+ /* make sure path exists */
+ rc = ul_path_get_dirfd(pc);
+ if (rc < 0)
+ return rc;
+
+ /* initialize sysfs blkdev specific stuff */
+ blk = ul_path_get_dialect(pc);
+ if (!blk) {
+ DBG(CXT, ul_debugobj(pc, "alloc new sysfs handler"));
+ blk = calloc(1, sizeof(struct sysfs_blkdev));
+ if (!blk)
+ return -ENOMEM;
+
+ ul_path_set_dialect(pc, blk, sysfs_blkdev_deinit_path);
+ ul_path_set_enoent_redirect(pc, sysfs_blkdev_enoent_redirect);
+ }
+
+ DBG(CXT, ul_debugobj(pc, "init sysfs stuff"));
+
+ blk->devno = devno;
+ sysfs_blkdev_set_parent(pc, parent);
+
+ return 0;
+}
+
+static void sysfs_blkdev_deinit_path(struct path_cxt *pc)
+{
+ struct sysfs_blkdev *blk;
+
+ if (!pc)
+ return;
+
+ DBG(CXT, ul_debugobj(pc, "deinit"));
+
+ blk = ul_path_get_dialect(pc);
+ if (!blk)
+ return;
+
+ ul_unref_path(blk->parent);
+ free(blk);
+
+ ul_path_set_dialect(pc, NULL, NULL);
+}
+
+int sysfs_blkdev_set_parent(struct path_cxt *pc, struct path_cxt *parent)
+{
+ struct sysfs_blkdev *blk = ul_path_get_dialect(pc);
+
+ if (!pc || !blk)
+ return -EINVAL;
+
+ if (blk->parent) {
+ ul_unref_path(blk->parent);
+ blk->parent = NULL;
+ }
+
+ if (parent) {
+ ul_ref_path(parent);
+ blk->parent = parent;
+ } else
+ blk->parent = NULL;
+
+ DBG(CXT, ul_debugobj(pc, "new parent"));
+ return 0;
+}
+
+struct path_cxt *sysfs_blkdev_get_parent(struct path_cxt *pc)
+{
+ struct sysfs_blkdev *blk = ul_path_get_dialect(pc);
+ return blk ? blk->parent : NULL;
+}
+
+/*
+ * Redirects ENOENT errors to the parent.
+ * For example
+ *
+ * /sys/dev/block/8:1/queue/logical_block_size redirects to
+ * /sys/dev/block/8:0/queue/logical_block_size
+ */
+static int sysfs_blkdev_enoent_redirect(struct path_cxt *pc, const char *path, int *dirfd)
+{
+ struct sysfs_blkdev *blk = ul_path_get_dialect(pc);
+
+ if (blk && blk->parent && path) {
+ *dirfd = ul_path_get_dirfd(blk->parent);
+ if (*dirfd >= 0) {
+ DBG(CXT, ul_debugobj(pc, "%s redirected to parent", path));
+ return 0;
+ }
+ }
+ return 1; /* no redirect */
+}
+
+char *sysfs_blkdev_get_name(struct path_cxt *pc, char *buf, size_t bufsiz)
+{
+ char link[PATH_MAX];
+ char *name;
+ ssize_t sz;
+
+ /* read /sys/dev/block/<maj:min> link */
+ sz = ul_path_readlink(pc, link, sizeof(link), NULL);
+ if (sz < 0)
+ return NULL;
+
+ name = strrchr(link, '/');
+ if (!name)
+ return NULL;
+
+ name++;
+ sz = strlen(name);
+ if ((size_t) sz + 1 > bufsiz)
+ return NULL;
+
+ memcpy(buf, name, sz + 1);
+ sysfs_devname_sys_to_dev(buf);
+ return buf;
+}
+
+int sysfs_blkdev_is_partition_dirent(DIR *dir, struct dirent *d, const char *parent_name)
+{
+ char path[NAME_MAX + 6 + 1];
+
+#ifdef _DIRENT_HAVE_D_TYPE
+ if (d->d_type != DT_DIR &&
+ d->d_type != DT_LNK &&
+ d->d_type != DT_UNKNOWN)
+ return 0;
+#endif
+ size_t len = 0;
+
+ if (parent_name) {
+ const char *p = parent_name;
+
+ /* /dev/sda --> "sda" */
+ if (*parent_name == '/') {
+ p = strrchr(parent_name, '/');
+ if (!p)
+ return 0;
+ p++;
+ }
+
+ len = strlen(p);
+ if ((strlen(d->d_name) <= len) || (strncmp(p, d->d_name, len) != 0))
+ len = 0;
+ }
+
+ if (len > 0) {
+ /* partitions subdir name is
+ * "<parent>[:digit:]" or "<parent>p[:digit:]"
+ */
+ return ((*(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;
+}
+
+int sysfs_blkdev_count_partitions(struct path_cxt *pc, const char *devname)
+{
+ DIR *dir;
+ struct dirent *d;
+ int r = 0;
+
+ dir = ul_path_opendir(pc, NULL);
+ if (!dir)
+ return 0;
+
+ while ((d = xreaddir(dir))) {
+ if (sysfs_blkdev_is_partition_dirent(dir, d, devname))
+ r++;
+ }
+
+ closedir(dir);
+ return r;
+}
+
+/*
+ * Converts @partno (partition number) to devno of the partition.
+ * The @pc handles wholedisk device.
+ *
+ * Note that this code does not expect any special format of the
+ * partitions devnames.
+ */
+dev_t sysfs_blkdev_partno_to_devno(struct path_cxt *pc, int partno)
+{
+ DIR *dir;
+ struct dirent *d;
+ dev_t devno = 0;
+
+ dir = ul_path_opendir(pc, NULL);
+ if (!dir)
+ return 0;
+
+ while ((d = xreaddir(dir))) {
+ int n;
+
+ if (!sysfs_blkdev_is_partition_dirent(dir, d, NULL))
+ continue;
+
+ if (ul_path_readf_s32(pc, &n, "%s/partition", d->d_name))
+ continue;
+
+ if (n == partno) {
+ if (ul_path_readf_majmin(pc, &devno, "%s/dev", d->d_name) == 0)
+ break;
+ }
+ }
+
+ closedir(dir);
+ DBG(CXT, ul_debugobj(pc, "partno (%d) -> devno (%d)", (int) partno, (int) devno));
+ return devno;
+}
+
+
+/*
+ * Returns slave name if there is only one slave, otherwise returns NULL.
+ * The result should be deallocated by free().
+ */
+char *sysfs_blkdev_get_slave(struct path_cxt *pc)
+{
+ DIR *dir;
+ struct dirent *d;
+ char *name = NULL;
+
+ dir = ul_path_opendir(pc, "slaves");
+ if (!dir)
+ 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;
+}
+
+
+#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 path contains all subsystems
+ * used for the device.
+ */
+char *sysfs_blkdev_get_devchain(struct path_cxt *pc, char *buf, size_t bufsz)
+{
+ /* read /sys/dev/block/<maj>:<min> symlink */
+ ssize_t ssz;
+ size_t sz = 0;
+ struct ul_buffer tmp = UL_INIT_BUFFER;
+ const char *p;
+ char *res = NULL;
+
+ ssz = ul_path_readlink(pc, buf, bufsz, NULL);
+ if (ssz <= 0)
+ return NULL;
+
+ if ((p = ul_path_get_prefix(pc)))
+ ul_buffer_append_string(&tmp, p);
+
+ ul_buffer_append_string(&tmp, _PATH_SYS_DEVBLOCK "/");
+ ul_buffer_append_data(&tmp, buf, ssz);
+
+ p = ul_buffer_get_data(&tmp, &sz, NULL);
+ if (p && sz < bufsz) {
+ memcpy(buf, p, sz);
+ res = buf;
+ }
+ ul_buffer_free_data(&tmp);
+ return res;
+}
+
+/*
+ * 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_blkdev_next_subsystem(struct path_cxt *pc __attribute__((unused)),
+ char *devchain, char **subsys)
+{
+ char subbuf[PATH_MAX];
+ char *sub;
+
+ if (!subsys || !devchain)
+ return -EINVAL;
+
+ *subsys = NULL;
+
+ while ((sub = get_subsystem(devchain, subbuf, sizeof(subbuf)))) {
+ *subsys = strdup(sub);
+ if (!*subsys)
+ return -ENOMEM;
+ return 0;
+ }
+
+ return 1;
+}
+
+#define REMOVABLE_FILENAME "/removable"
+
+/*
+ * 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
+ */
+static int sysfs_devchain_is_removable(char *chain)
+{
+ size_t len;
+ char buf[20];
+ char *p;
+
+ if (!chain || !*chain)
+ return 0;
+
+ len = strlen(chain);
+ if (len + sizeof(REMOVABLE_FILENAME) > PATH_MAX)
+ return 0;
+
+ do {
+ int fd, rc;
+
+ /* append "/removable" to the path */
+ memcpy(chain + len, REMOVABLE_FILENAME, sizeof(REMOVABLE_FILENAME));
+
+ /* try to read it */
+ fd = open(chain, O_RDONLY);
+ if (fd != -1) {
+ rc = read_all(fd, buf, sizeof(buf));
+ close(fd);
+
+ if (rc > 0) {
+ if (strncmp(buf, "fixed", min(rc, 5)) == 0) {
+ return 0;
+ } else if (strncmp(buf, "removable", min(rc, 9)) == 0) {
+ return 1;
+ }
+ }
+ }
+
+ /* remove last subsystem from chain */
+ chain[len] = '\0';
+ p = strrchr(chain, '/');
+ if (p) {
+ *p = '\0';
+ len = p - chain;
+ }
+
+ } while (p);
+
+ return 0;
+}
+
+int sysfs_blkdev_is_hotpluggable(struct path_cxt *pc)
+{
+ char buf[PATH_MAX], *chain;
+
+ chain = sysfs_blkdev_get_devchain(pc, buf, sizeof(buf));
+ return sysfs_devchain_is_removable(chain);
+}
+
+int sysfs_blkdev_is_removable(struct path_cxt *pc)
+{
+ int rc = 0;
+
+ // FIXME usb is not actually removable
+
+ /* check /sys/dev/block/<maj>:<min>/removable attribute */
+ if (ul_path_read_s32(pc, &rc, "removable") == 0)
+ return rc;
+
+ return 0;
+}
+
+static int get_dm_wholedisk(struct path_cxt *pc, char *diskname,
+ size_t len, dev_t *diskdevno)
+{
+ int rc = 0;
+ char *name;
+
+ /* Note, sysfs_blkdev_get_slave() returns the first slave only,
+ * if there is more slaves, then return NULL
+ */
+ name = sysfs_blkdev_get_slave(pc);
+ if (!name)
+ return -1;
+
+ if (diskname && len)
+ xstrncpy(diskname, name, len);
+
+ if (diskdevno) {
+ *diskdevno = __sysfs_devname_to_devno(ul_path_get_prefix(pc), name, NULL);
+ if (!*diskdevno)
+ rc = -1;
+ }
+
+ free(name);
+ return rc;
+}
+
+/*
+ * Returns by @diskdevno whole disk device devno and (optionally) by
+ * @diskname the whole disk device name.
+ */
+int sysfs_blkdev_get_wholedisk( struct path_cxt *pc,
+ char *diskname,
+ size_t len,
+ dev_t *diskdevno)
+{
+ int is_part = 0;
+
+ if (!pc)
+ return -1;
+
+ is_part = ul_path_access(pc, F_OK, "partition") == 0;
+ if (!is_part) {
+ /*
+ * Extra case for partitions mapped by device-mapper.
+ *
+ * All regular 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 = NULL, *tmp, *prefix;
+
+ ul_path_read_string(pc, &uuid, "dm/uuid");
+ tmp = uuid;
+ prefix = uuid ? strsep(&tmp, "-") : NULL;
+
+ if (prefix && strncasecmp(prefix, "part", 4) == 0)
+ is_part = 1;
+ free(uuid);
+
+ if (is_part &&
+ get_dm_wholedisk(pc, diskname, len, diskdevno) == 0)
+ /*
+ * partitioned device, mapped by DM
+ */
+ goto done;
+
+ is_part = 0;
+ }
+
+ if (!is_part) {
+ /*
+ * unpartitioned device
+ */
+ if (diskname && !sysfs_blkdev_get_name(pc, diskname, len))
+ goto err;
+ if (diskdevno)
+ *diskdevno = sysfs_blkdev_get_devno(pc);
+
+ } 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;
+ ssize_t linklen;
+
+ linklen = ul_path_readlink(pc, linkpath, sizeof(linkpath), NULL);
+ if (linklen < 0)
+ goto err;
+
+ stripoff_last_component(linkpath); /* dirname */
+ name = stripoff_last_component(linkpath); /* basename */
+ if (!name)
+ goto err;
+
+ sysfs_devname_sys_to_dev(name);
+ if (diskname && len)
+ xstrncpy(diskname, name, len);
+
+ if (diskdevno) {
+ *diskdevno = __sysfs_devname_to_devno(ul_path_get_prefix(pc), name, NULL);
+ if (!*diskdevno)
+ goto err;
+ }
+ }
+
+done:
+ return 0;
+err:
+ return -1;
+}
+
+int sysfs_devno_to_wholedisk(dev_t devno, char *diskname,
+ size_t len, dev_t *diskdevno)
+{
+ struct path_cxt *pc;
+ int rc = 0;
+
+ if (!devno)
+ return -EINVAL;
+ pc = ul_new_sysfs_path(devno, NULL, NULL);
+ if (!pc)
+ return -ENOMEM;
+
+ rc = sysfs_blkdev_get_wholedisk(pc, diskname, len, diskdevno);
+ ul_unref_path(pc);
+ return rc;
+}
+
+/*
+ * Returns 1 if the device is private device mapper device. The @uuid
+ * (if not NULL) returns DM device UUID, use free() to deallocate.
+ */
+int sysfs_devno_is_dm_private(dev_t devno, char **uuid)
+{
+ struct path_cxt *pc = NULL;
+ char *id = NULL;
+ int rc = 0;
+
+ pc = ul_new_sysfs_path(devno, NULL, NULL);
+ if (!pc)
+ goto done;
+ if (ul_path_read_string(pc, &id, "dm/uuid") <= 0 || !id)
+ goto done;
+
+ /* Private LVM devices use "LVM-<uuid>-<name>" uuid format (important
+ * is the "LVM" prefix and "-<name>" postfix).
+ */
+ if (strncmp(id, "LVM-", 4) == 0) {
+ char *p = strrchr(id + 4, '-');
+
+ if (p && *(p + 1))
+ rc = 1;
+
+ /* Private Stratis devices prefix the UUID with "stratis-1-private"
+ */
+ } else if (strncmp(id, "stratis-1-private", 17) == 0) {
+ rc = 1;
+ }
+done:
+ ul_unref_path(pc);
+ if (uuid)
+ *uuid = id;
+ else
+ free(id);
+ 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_blkdev_scsi_get_hctl(struct path_cxt *pc, int *h, int *c, int *t, int *l)
+{
+ char buf[PATH_MAX], *hctl;
+ struct sysfs_blkdev *blk;
+ ssize_t len;
+
+ blk = ul_path_get_dialect(pc);
+
+ if (!blk || blk->hctl_error)
+ return -EINVAL;
+ if (blk->has_hctl)
+ goto done;
+
+ blk->hctl_error = 1;
+ len = ul_path_readlink(pc, buf, sizeof(buf), "device");
+ if (len < 0)
+ return len;
+
+ hctl = strrchr(buf, '/');
+ if (!hctl)
+ return -1;
+ hctl++;
+
+ if (sscanf(hctl, "%u:%u:%u:%u", &blk->scsi_host, &blk->scsi_channel,
+ &blk->scsi_target, &blk->scsi_lun) != 4)
+ return -1;
+
+ blk->has_hctl = 1;
+done:
+ if (h)
+ *h = blk->scsi_host;
+ if (c)
+ *c = blk->scsi_channel;
+ if (t)
+ *t = blk->scsi_target;
+ if (l)
+ *l = blk->scsi_lun;
+
+ blk->hctl_error = 0;
+ return 0;
+}
+
+
+static char *scsi_host_attribute_path(
+ struct path_cxt *pc,
+ const char *type,
+ char *buf,
+ size_t bufsz,
+ const char *attr)
+{
+ int len;
+ int host;
+ const char *prefix;
+
+ if (sysfs_blkdev_scsi_get_hctl(pc, &host, NULL, NULL, NULL))
+ return NULL;
+
+ prefix = ul_path_get_prefix(pc);
+ if (!prefix)
+ prefix = "";
+
+ if (attr)
+ len = snprintf(buf, bufsz, "%s%s/%s_host/host%d/%s",
+ prefix, _PATH_SYS_CLASS, type, host, attr);
+ else
+ len = snprintf(buf, bufsz, "%s%s/%s_host/host%d",
+ prefix, _PATH_SYS_CLASS, type, host);
+
+ return (len < 0 || (size_t) len >= bufsz) ? NULL : buf;
+}
+
+char *sysfs_blkdev_scsi_host_strdup_attribute(struct path_cxt *pc,
+ const char *type, const char *attr)
+{
+ char buf[1024];
+ int rc;
+ FILE *f;
+
+ if (!attr || !type ||
+ !scsi_host_attribute_path(pc, 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_blkdev_scsi_host_is(struct path_cxt *pc, const char *type)
+{
+ char buf[PATH_MAX];
+ struct stat st;
+
+ if (!type || !scsi_host_attribute_path(pc, type,
+ buf, sizeof(buf), NULL))
+ return 0;
+
+ return stat(buf, &st) == 0 && S_ISDIR(st.st_mode);
+}
+
+static char *scsi_attribute_path(struct path_cxt *pc,
+ char *buf, size_t bufsz, const char *attr)
+{
+ int len, h, c, t, l;
+ const char *prefix;
+
+ if (sysfs_blkdev_scsi_get_hctl(pc, &h, &c, &t, &l) != 0)
+ return NULL;
+
+ prefix = ul_path_get_prefix(pc);
+ if (!prefix)
+ prefix = "";
+
+ if (attr)
+ len = snprintf(buf, bufsz, "%s%s/devices/%d:%d:%d:%d/%s",
+ prefix, _PATH_SYS_SCSI,
+ h,c,t,l, attr);
+ else
+ len = snprintf(buf, bufsz, "%s%s/devices/%d:%d:%d:%d",
+ prefix, _PATH_SYS_SCSI,
+ h,c,t,l);
+ return (len < 0 || (size_t) len >= bufsz) ? NULL : buf;
+}
+
+int sysfs_blkdev_scsi_has_attribute(struct path_cxt *pc, const char *attr)
+{
+ char path[PATH_MAX];
+ struct stat st;
+
+ if (!scsi_attribute_path(pc, path, sizeof(path), attr))
+ return 0;
+
+ return stat(path, &st) == 0;
+}
+
+int sysfs_blkdev_scsi_path_contains(struct path_cxt *pc, const char *pattern)
+{
+ char path[PATH_MAX], linkc[PATH_MAX];
+ struct stat st;
+ ssize_t len;
+
+ if (!scsi_attribute_path(pc, 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;
+}
+
+static dev_t read_devno(const char *path)
+{
+ FILE *f;
+ int maj = 0, min = 0;
+ dev_t dev = 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;
+}
+
+int sysfs_devname_is_hidden(const char *prefix, const char *name)
+{
+ char buf[PATH_MAX];
+ int rc = 0, hidden = 0, len;
+ FILE *f;
+
+ if (strncmp("/dev/", name, 5) == 0)
+ return 0;
+
+ if (!prefix)
+ prefix = "";
+ /*
+ * Create path to /sys/block/<name>/hidden
+ */
+ len = snprintf(buf, sizeof(buf),
+ "%s" _PATH_SYS_BLOCK "/%s/hidden",
+ prefix, name);
+
+ if (len < 0 || (size_t) len + 1 > sizeof(buf))
+ return 0;
+
+ f = fopen(buf, "r" UL_CLOEXECSTR);
+ if (!f)
+ return 0;
+
+ rc = fscanf(f, "%d", &hidden);
+ fclose(f);
+
+ return rc == 1 ? hidden : 0;
+}
+
+
+dev_t __sysfs_devname_to_devno(const char *prefix, const char *name, const char *parent)
+{
+ char buf[PATH_MAX];
+ char *_name = NULL, *_parent = NULL; /* name as encoded in sysfs */
+ dev_t dev = 0;
+ int len;
+
+ if (!prefix)
+ prefix = "";
+
+ assert(name);
+
+ if (strncmp("/dev/", name, 5) == 0) {
+ /*
+ * Read from /dev
+ */
+ struct stat st;
+
+ if (stat(name, &st) == 0) {
+ dev = st.st_rdev;
+ goto done;
+ }
+ name += 5; /* unaccessible, or not node in /dev */
+ }
+
+ _name = strdup(name);
+ if (!_name)
+ goto done;
+ sysfs_devname_dev_to_sys(_name);
+
+ if (parent) {
+ _parent = strdup(parent);
+ if (!_parent)
+ goto done;
+ }
+
+ if (parent && strncmp("dm-", name, 3) != 0) {
+ /*
+ * Create path to /sys/block/<parent>/<name>/dev
+ */
+ sysfs_devname_dev_to_sys(_parent);
+ len = snprintf(buf, sizeof(buf),
+ "%s" _PATH_SYS_BLOCK "/%s/%s/dev",
+ prefix, _parent, _name);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ goto done;
+
+ /* don't try anything else for dm-* */
+ dev = read_devno(buf);
+ goto done;
+ }
+
+ /*
+ * Read from /sys/block/<sysname>/dev
+ */
+ len = snprintf(buf, sizeof(buf),
+ "%s" _PATH_SYS_BLOCK "/%s/dev",
+ prefix, _name);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ goto done;
+ dev = read_devno(buf);
+
+ /*
+ * Read from /sys/block/<parent>/<partition>/dev
+ */
+ if (!dev && parent && startswith(name, parent)) {
+ len = snprintf(buf, sizeof(buf),
+ "%s" _PATH_SYS_BLOCK "/%s/%s/dev",
+ prefix, _parent, _name);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ goto done;
+ dev = read_devno(buf);
+ }
+
+ /*
+ * Read from /sys/block/<sysname>/device/dev
+ */
+ if (!dev) {
+ len = snprintf(buf, sizeof(buf),
+ "%s" _PATH_SYS_BLOCK "/%s/device/dev",
+ prefix, _name);
+ if (len < 0 || (size_t) len >= sizeof(buf))
+ goto done;
+ dev = read_devno(buf);
+ }
+done:
+ free(_name);
+ free(_parent);
+ return dev;
+}
+
+dev_t sysfs_devname_to_devno(const char *name)
+{
+ return __sysfs_devname_to_devno(NULL, name, NULL);
+}
+
+char *sysfs_blkdev_get_path(struct path_cxt *pc, char *buf, size_t bufsiz)
+{
+ const char *name = sysfs_blkdev_get_name(pc, buf, bufsiz);
+ char *res = NULL;
+ size_t sz;
+ struct stat st;
+
+ if (!name)
+ goto done;
+
+ sz = strlen(name);
+ if (sz + sizeof("/dev/") > bufsiz)
+ goto done;
+
+ /* 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 == sysfs_blkdev_get_devno(pc))
+ res = buf;
+done:
+ return res;
+}
+
+dev_t sysfs_blkdev_get_devno(struct path_cxt *pc)
+{
+ return ((struct sysfs_blkdev *) ul_path_get_dialect(pc))->devno;
+}
+
+/*
+ * Returns devname (e.g. "/dev/sda1") for the given devno.
+ *
+ * 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 path_cxt *pc = ul_new_sysfs_path(devno, NULL, NULL);
+ char *res = NULL;
+
+ if (pc) {
+ res = sysfs_blkdev_get_path(pc, buf, bufsiz);
+ ul_unref_path(pc);
+ }
+ return res;
+}
+
+char *sysfs_devno_to_devname(dev_t devno, char *buf, size_t bufsiz)
+{
+ struct path_cxt *pc = ul_new_sysfs_path(devno, NULL, NULL);
+ char *res = NULL;
+
+ if (pc) {
+ res = sysfs_blkdev_get_name(pc, buf, bufsiz);
+ ul_unref_path(pc);
+ }
+ return res;
+}
+
+int sysfs_devno_count_partitions(dev_t devno)
+{
+ struct path_cxt *pc = ul_new_sysfs_path(devno, NULL, NULL);
+ int n = 0;
+
+ if (pc) {
+ char buf[PATH_MAX + 1];
+ char *name = sysfs_blkdev_get_name(pc, buf, sizeof(buf));
+
+ n = sysfs_blkdev_count_partitions(pc, name);
+ ul_unref_path(pc);
+ }
+ return n;
+}
+
+char *sysfs_chrdev_devno_to_devname(dev_t devno, char *buf, size_t bufsiz)
+{
+ char link[PATH_MAX];
+ struct path_cxt *pc;
+ char *name;
+ ssize_t sz;
+
+ pc = ul_new_path(_PATH_SYS_DEVCHAR "/%u:%u", major(devno), minor(devno));
+ if (!pc)
+ return NULL;
+
+ /* read /sys/dev/char/<maj:min> link */
+ sz = ul_path_readlink(pc, link, sizeof(link), NULL);
+ ul_unref_path(pc);
+
+ if (sz < 0)
+ return NULL;
+
+ name = strrchr(link, '/');
+ if (!name)
+ return NULL;
+
+ name++;
+ sz = strlen(name);
+ if ((size_t) sz + 1 > bufsiz)
+ return NULL;
+
+ memcpy(buf, name, sz + 1);
+ sysfs_devname_sys_to_dev(buf);
+ return buf;
+
+}
+
+enum sysfs_byteorder sysfs_get_byteorder(struct path_cxt *pc)
+{
+ int rc;
+ char buf[BUFSIZ];
+ enum sysfs_byteorder ret;
+
+ rc = ul_path_read_buffer(pc, buf, sizeof(buf), _PATH_SYS_CPU_BYTEORDER);
+ if (rc < 0)
+ goto unknown;
+
+ if (strncmp(buf, "little", sizeof(buf)) == 0) {
+ ret = SYSFS_BYTEORDER_LITTLE;
+ goto out;
+ } else if (strncmp(buf, "big", sizeof(buf)) == 0) {
+ ret = SYSFS_BYTEORDER_BIG;
+ goto out;
+ }
+
+unknown:
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ ret = SYSFS_BYTEORDER_LITTLE;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ ret = SYSFS_BYTEORDER_BIG;
+#else
+#error Unknown byte order
+#endif
+
+out:
+ return ret;
+}
+
+int sysfs_get_address_bits(struct path_cxt *pc)
+{
+ int rc;
+ int address_bits;
+
+ rc = ul_path_scanf(pc, _PATH_SYS_ADDRESS_BITS, "%d", &address_bits);
+ if (rc < 0)
+ return rc;
+ if (address_bits < 0)
+ return -EINVAL;
+ return address_bits;
+}
+
+
+#ifdef TEST_PROGRAM_SYSFS
+#include <errno.h>
+#include <err.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+ struct path_cxt *pc;
+ char *devname;
+ dev_t devno, disk_devno;
+ char path[PATH_MAX], *sub, *chain;
+ char diskname[32];
+ int i, is_part, rc = EXIT_SUCCESS;
+ uint64_t u64;
+
+ if (argc != 2)
+ errx(EXIT_FAILURE, "usage: %s <devname>", argv[0]);
+
+ ul_sysfs_init_debug();
+
+ devname = argv[1];
+ devno = sysfs_devname_to_devno(devname);
+
+ if (!devno)
+ err(EXIT_FAILURE, "failed to read devno");
+
+ printf("non-context:\n");
+ printf(" DEVNO: %u (%d:%d)\n", (unsigned int) devno, major(devno), minor(devno));
+ printf(" DEVNAME: %s\n", sysfs_devno_to_devname(devno, path, sizeof(path)));
+ printf(" DEVPATH: %s\n", sysfs_devno_to_devpath(devno, path, sizeof(path)));
+
+ sysfs_devno_to_wholedisk(devno, diskname, sizeof(diskname), &disk_devno);
+ printf(" WHOLEDISK-DEVNO: %u (%d:%d)\n", (unsigned int) disk_devno, major(disk_devno), minor(disk_devno));
+ printf(" WHOLEDISK-DEVNAME: %s\n", diskname);
+
+ pc = ul_new_sysfs_path(devno, NULL, NULL);
+ if (!pc)
+ goto done;
+
+ printf("context based:\n");
+ devno = sysfs_blkdev_get_devno(pc);
+ printf(" DEVNO: %u (%d:%d)\n", (unsigned int) devno, major(devno), minor(devno));
+ printf(" DEVNAME: %s\n", sysfs_blkdev_get_name(pc, path, sizeof(path)));
+ printf(" DEVPATH: %s\n", sysfs_blkdev_get_path(pc, path, sizeof(path)));
+
+ sysfs_devno_to_wholedisk(devno, diskname, sizeof(diskname), &disk_devno);
+ printf(" WHOLEDISK-DEVNO: %u (%d:%d)\n", (unsigned int) disk_devno, major(disk_devno), minor(disk_devno));
+ printf(" WHOLEDISK-DEVNAME: %s\n", diskname);
+
+ is_part = ul_path_access(pc, F_OK, "partition") == 0;
+ printf(" PARTITION: %s\n", is_part ? "YES" : "NOT");
+
+ if (is_part && disk_devno) {
+ struct path_cxt *disk_pc = ul_new_sysfs_path(disk_devno, NULL, NULL);
+ sysfs_blkdev_set_parent(pc, disk_pc);
+
+ ul_unref_path(disk_pc);
+ }
+
+ printf(" HOTPLUG: %s\n", sysfs_blkdev_is_hotpluggable(pc) ? "yes" : "no");
+ printf(" REMOVABLE: %s\n", sysfs_blkdev_is_removable(pc) ? "yes" : "no");
+ printf(" SLAVES: %d\n", ul_path_count_dirents(pc, "slaves"));
+
+ if (!is_part) {
+ printf("First 5 partitions:\n");
+ for (i = 1; i <= 5; i++) {
+ dev_t dev = sysfs_blkdev_partno_to_devno(pc, i);
+ if (dev)
+ printf("\t#%d %d:%d\n", i, major(dev), minor(dev));
+ }
+ }
+
+ if (ul_path_read_u64(pc, &u64, "size") != 0)
+ printf(" (!) read SIZE failed\n");
+ else
+ printf(" SIZE: %jd\n", u64);
+
+ if (ul_path_read_s32(pc, &i, "queue/hw_sector_size"))
+ printf(" (!) read SECTOR failed\n");
+ else
+ printf(" SECTOR: %d\n", i);
+
+
+ chain = sysfs_blkdev_get_devchain(pc, path, sizeof(path));
+ printf(" SUBSYSTEMS:\n");
+
+ while (chain && sysfs_blkdev_next_subsystem(pc, chain, &sub) == 0) {
+ printf("\t%s\n", sub);
+ free(sub);
+ }
+
+ rc = EXIT_SUCCESS;
+done:
+ ul_unref_path(pc);
+ return rc;
+}
+#endif /* TEST_PROGRAM_SYSFS */