+/*
+ * device-discovery.c: main function, discovering device and processing
+ * pipe request from kernel.
+ *
+ * Copyright (c) 2010 EMC Corporation, Haiying Tang <Tang_Haiying@emc.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/select.h>
+#include <linux/kdev_t.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/sg.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <errno.h>
+#include <libdevmapper.h>
+
+#include "device-discovery.h"
+
+#define BL_PIPE_FILE "/var/lib/nfs/rpc_pipefs/nfs/blocklayout"
+#define PID_FILE "/var/run/blkmapd.pid"
+
+struct bl_disk *visible_disk_list;
+
+struct bl_disk_path *bl_get_path(const char *filepath,
+ struct bl_disk_path *paths)
+{
+ struct bl_disk_path *tmp = paths;
+
+ while (tmp) {
+ if (!strcmp(tmp->full_path, filepath))
+ break;
+ tmp = tmp->next;
+ }
+ return tmp;
+}
+
+/* Check whether valid_path is a substring(partition) of path */
+int bl_is_partition(struct bl_disk_path *valid_path, struct bl_disk_path *path)
+{
+ if (!strncmp(valid_path->full_path, path->full_path,
+ strlen(valid_path->full_path)))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * For multipath devices, devices state could be PASSIVE/ACTIVE/PSEUDO,
+ * where PSEUDO > ACTIVE > PASSIVE. Device with highest state is used to
+ * create pseudo device. So if state is higher, the device path needs to
+ * be updated.
+ * If device-mapper multipath support is a must, pseudo devices should
+ * exist for each multipath device. If not, active device path will be
+ * chosen for device creation.
+ * Treat partition as invalid path.
+ */
+int bl_update_path(struct bl_disk_path *path, enum bl_path_state_e state,
+ struct bl_disk *disk)
+{
+ struct bl_disk_path *valid_path = disk->valid_path;
+
+ if (valid_path) {
+ if (valid_path->state >= state) {
+ if (bl_is_partition(valid_path, path))
+ return 0;
+ }
+ }
+ return 1;
+}
+
+void bl_release_disk(void)
+{
+ struct bl_disk *disk;
+ struct bl_disk_path *path = NULL;
+
+ while (visible_disk_list) {
+ disk = visible_disk_list;
+ path = disk->paths;
+ while (path) {
+ disk->paths = path->next;
+ free(path->full_path);
+ free(path);
+ path = disk->paths;
+ }
+ if (disk->serial)
+ free(disk->serial);
+ visible_disk_list = disk->next;
+ free(disk);
+ }
+}
+
+void bl_add_disk(char *filepath)
+{
+ struct bl_disk *disk = NULL;
+ int fd = 0;
+ struct stat sb;
+ off_t size = 0;
+ struct bl_serial *serial = NULL;
+ enum bl_path_state_e ap_state;
+ struct bl_disk_path *diskpath = NULL, *path = NULL;
+ dev_t dev;
+
+ fd = open(filepath, O_RDONLY | O_LARGEFILE);
+ if (fd < 0)
+ return;
+
+ if (fstat(fd, &sb)) {
+ close(fd);
+ return;
+ }
+
+ if (!sb.st_size)
+ ioctl(fd, BLKGETSIZE, &size);
+ else
+ size = sb.st_size;
+
+ if (!size) {
+ close(fd);
+ return;
+ }
+
+ dev = sb.st_rdev;
+ serial = bldev_read_serial(fd, filepath);
+ if (dm_is_dm_major(major(dev)))
+ ap_state = BL_PATH_STATE_PSEUDO;
+ else
+ ap_state = bldev_read_ap_state(fd);
+ close(fd);
+
+ if (ap_state != BL_PATH_STATE_ACTIVE)
+ return;
+
+ for (disk = visible_disk_list; disk != NULL; disk = disk->next) {
+ /* Already scanned or a partition?
+ * XXX: if released each time, maybe not need to compare
+ */
+ if ((serial->len == disk->serial->len) &&
+ !memcmp(serial->data, disk->serial->data, serial->len)) {
+ diskpath = bl_get_path(filepath, disk->paths);
+ break;
+ }
+ }
+
+ if (disk && diskpath)
+ return;
+
+ /* add path */
+ path = malloc(sizeof(struct bl_disk_path));
+ if (!path) {
+ BL_LOG_ERR("%s: Out of memory!\n", __func__);
+ goto out_err;
+ }
+ path->next = NULL;
+ path->state = ap_state;
+ path->full_path = strdup(filepath);
+ if (!path->full_path)
+ goto out_err;
+
+ if (!disk) { /* add disk */
+ disk = malloc(sizeof(struct bl_disk));
+ if (!disk) {
+ BL_LOG_ERR("%s: Out of memory!\n", __func__);
+ goto out_err;
+ }
+ disk->next = visible_disk_list;
+ disk->dev = dev;
+ disk->size = size;
+ disk->serial = serial;
+ disk->valid_path = path;
+ disk->paths = path;
+ visible_disk_list = disk;
+ } else {
+ path->next = disk->paths;
+ disk->paths = path;
+ /* check whether we need to update disk info */
+ if (bl_update_path(path, path->state, disk)) {
+ disk->dev = dev;
+ disk->size = size;
+ disk->valid_path = path;
+ }
+ }
+ return;
+
+ out_err:
+ if (path) {
+ if (path->full_path)
+ free(path->full_path);
+ free(path);
+ }
+ return;
+}
+
+int bl_discover_devices(void)
+{
+ FILE *f;
+ int n;
+ char buf[PATH_MAX], devname[PATH_MAX], fulldevname[PATH_MAX];
+
+ /* release previous list */
+ bl_release_disk();
+
+ /* scan all block devices */
+ f = fopen("/proc/partitions", "r");
+ if (f == NULL)
+ return 0;
+
+ while (1) {
+ if (fgets(buf, sizeof buf, f) == NULL)
+ break;
+ n = sscanf(buf, "%*d %*d %*d %31s", devname);
+ if (n != 1)
+ continue;
+ snprintf(fulldevname, sizeof fulldevname, "/sys/block/%s",
+ devname);
+ if (access(fulldevname, F_OK) < 0)
+ continue;
+ snprintf(fulldevname, sizeof fulldevname, "/dev/%s", devname);
+ bl_add_disk(fulldevname);
+ }
+
+ fclose(f);
+
+ return 0;
+}
+
+/* process kernel request
+ * return 0: request processed, and no more request waiting;
+ * return 1: request processed, and more requests waiting;
+ * return < 0: error
+ */
+int bl_disk_inquiry_process(int fd)
+{
+ int ret = 0;
+ struct bl_pipemsg_hdr head;
+ char *buf = NULL;
+ uint32_t major, minor;
+ uint16_t buflen;
+ struct bl_dev_msg reply;
+
+ /* read request */
+ if (atomicio(read, fd, &head, sizeof(head)) != sizeof(head)) {
+ /* Note that an error in this or the next read is pretty
+ * catastrophic, as there is no good way to resync into
+ * the pipe's stream.
+ */
+ BL_LOG_ERR("Read pipefs head error!\n");
+ ret = -EIO;
+ goto out;
+ }
+
+ buflen = head.totallen;
+ buf = malloc(buflen);
+ if (!buf) {
+ BL_LOG_ERR("%s: Out of memory!\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (atomicio(read, fd, buf, buflen) != buflen) {
+ BL_LOG_ERR("Read pipefs content error!\n");
+ ret = -EIO;
+ goto out;
+ }
+
+ reply.status = BL_DEVICE_REQUEST_PROC;
+
+ switch (head.type) {
+ case BL_DEVICE_MOUNT:
+ /*
+ * It shouldn't be necessary to discover devices here, since
+ * process_deviceinfo() will re-discover if it can't find
+ * the devices it needs. But in the case of multipath
+ * devices (ones that appear more than once, for example an
+ * active and a standby LUN), this will re-order them in the
+ * correct priority.
+ */
+ bl_discover_devices();
+ if (!process_deviceinfo(buf, buflen, &major, &minor)) {
+ reply.status = BL_DEVICE_REQUEST_ERR;
+ break;
+ }
+ reply.major = major;
+ reply.minor = minor;
+ break;
+ case BL_DEVICE_UMOUNT:
+ if (!dm_device_remove_all((uint64_t *) buf))
+ reply.status = BL_DEVICE_REQUEST_ERR;
+ break;
+ default:
+ reply.status = BL_DEVICE_REQUEST_ERR;
+ break;
+ }
+
+ /* write to pipefs */
+ if (atomicio((void *)write, fd, &reply, sizeof(reply))
+ != sizeof(reply)) {
+ BL_LOG_ERR("Write pipefs error!\n");
+ ret = -EIO;
+ }
+
+ out:
+ if (buf)
+ free(buf);
+ return ret;
+}
+
+/* TODO: set bl_process_stop to 1 in command */
+unsigned int bl_process_stop;
+
+int bl_run_disk_inquiry_process(int fd)
+{
+ fd_set rset;
+ int ret;
+
+ bl_process_stop = 0;
+
+ for (;;) {
+ if (bl_process_stop)
+ return 1;
+ FD_ZERO(&rset);
+ FD_SET(fd, &rset);
+ ret = 0;
+ switch (select(fd + 1, &rset, NULL, NULL, NULL)) {
+ case -1:
+ if (errno == EINTR)
+ continue;
+ else {
+ ret = -errno;
+ goto out;
+ }
+ case 0:
+ goto out;
+ default:
+ if (FD_ISSET(fd, &rset))
+ ret = bl_disk_inquiry_process(fd);
+ }
+ }
+ out:
+ return ret;
+}
+
+/* Daemon */
+int main(int argc, char **argv)
+{
+ int fd, pidfd = -1, opt, dflag = 0, fg = 0, ret = 1;
+ struct stat statbuf;
+ char pidbuf[64];
+
+ while ((opt = getopt(argc, argv, "df")) != -1) {
+ switch (opt) {
+ case 'd':
+ dflag = 1;
+ break;
+ case 'f':
+ fg = 1;
+ break;
+ }
+ }
+
+ if (fg) {
+ openlog("blkmapd", LOG_PERROR, 0);
+ } else {
+ if (!stat(PID_FILE, &statbuf)) {
+ fprintf(stderr, "Pid file %s already existed\n", PID_FILE);
+ exit(1);
+ }
+
+ if (daemon(0, 0) != 0) {
+ fprintf(stderr, "Daemonize failed\n");
+ exit(1);
+ }
+
+ openlog("blkmapd", LOG_PID, 0);
+ pidfd = open(PID_FILE, O_WRONLY | O_CREAT, 0644);
+ if (pidfd < 0) {
+ BL_LOG_ERR("Create pid file %s failed\n", PID_FILE);
+ exit(1);
+ }
+
+ if (lockf(pidfd, F_TLOCK, 0) < 0) {
+ BL_LOG_ERR("Lock pid file %s failed\n", PID_FILE);
+ close(pidfd);
+ exit(1);
+ }
+ ftruncate(pidfd, 0);
+ sprintf(pidbuf, "%d\n", getpid());
+ write(pidfd, pidbuf, strlen(pidbuf));
+ }
+
+ if (dflag) {
+ bl_discover_devices();
+ exit(0);
+ }
+
+ /* open pipe file */
+ fd = open(BL_PIPE_FILE, O_RDWR);
+ if (fd < 0) {
+ BL_LOG_ERR("open pipe file %s error\n", BL_PIPE_FILE);
+ exit(1);
+ }
+
+ while (1) {
+ /* discover device when needed */
+ bl_discover_devices();
+
+ ret = bl_run_disk_inquiry_process(fd);
+ if (ret < 0) {
+ /* what should we do with process error? */
+ BL_LOG_ERR("inquiry process return %d\n", ret);
+ }
+ }
+
+ if (pidfd >= 0) {
+ close(pidfd);
+ unlink(PID_FILE);
+ }
+
+ exit(ret);
+}
projects / nfs-utils.git / blobdiff