[libmultipath] update sysfs code

This updates the sysfs code to work with the latest driver core
changes. Copied from udev sources.

diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c
index b9621ac..9f11b95 100644 (file)
--- a/libmultipath/sysfs.c
+++ b/libmultipath/sysfs.c
@@ -4,12 +4,12 @@
  *     This program is free software; you can redistribute it and/or modify it
  *     under the terms of the GNU General Public License as published by the
  *     Free Software Foundation version 2 of the License.
- * 
+ *
  *     This program is distributed in the hope that it will be useful, but
  *     WITHOUT ANY WARRANTY; without even the implied warranty of
  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *     General Public License for more details.
- * 
+ *
  *     You should have received a copy of the GNU General Public License along
  *     with this program; if not, write to the Free Software Foundation, Inc.,
  *     51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
@@ -58,7 +58,7 @@ int sysfs_init(char *path, size_t len)
                strlcpy(sysfs_path, path, len);
                remove_trailing_chars(sysfs_path, '/');
        } else
-               strlcpy(sysfs_path, "/sys", len);
+               strlcpy(sysfs_path, "/sys", sizeof(sysfs_path));
        dbg("sysfs_path='%s'", sysfs_path);
 
        INIT_LIST_HEAD(&attr_list);
@@ -80,6 +80,7 @@ void sysfs_cleanup(void)
        }
 
        list_for_each_entry_safe(sysdev_loop, sysdev_temp, &sysfs_dev_list, node) {
+               list_del(&sysdev_loop->node);
                free(sysdev_loop);
        }
 }
@@ -162,9 +163,23 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
        int len;
        char *pos;
 
+       /* we handle only these devpathes */
+       if (devpath != NULL &&
+           strncmp(devpath, "/devices/", 9) != 0 &&
+           strncmp(devpath, "/subsystem/", 11) != 0 &&
+           strncmp(devpath, "/module/", 8) != 0 &&
+           strncmp(devpath, "/bus/", 5) != 0 &&
+           strncmp(devpath, "/class/", 7) != 0 &&
+           strncmp(devpath, "/block/", 7) != 0) {
+               dbg("invalid devpath '%s'", devpath);
+               return NULL;
+       }
+
        dbg("open '%s'", devpath);
        strlcpy(devpath_real, devpath, sizeof(devpath_real));
        remove_trailing_chars(devpath_real, '/');
+       if (devpath[0] == '\0' )
+               return NULL;
 
        /* if we got a link, resolve it to the real device */
        strlcpy(path, sysfs_path, sizeof(path));
@@ -174,24 +189,26 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
                dbg("stat '%s' failed: %s", path, strerror(errno));
                list_for_each_entry(sysdev_loop, &sysfs_dev_list, node) {
                        if (strcmp(sysdev_loop->dev.devpath, devpath_real) == 0) {
-                               dbg("found vanished dev in cache '%s'", sysdev_loop->dev.devpath);
+                               dbg("found vanished dev in cache '%s'",
+                                   sysdev_loop->dev.devpath);
                                return &sysdev_loop->dev;
                        }
                }
                return NULL;
        }
+
        if (S_ISLNK(statbuf.st_mode)) {
                if (sysfs_resolve_link(devpath_real, sizeof(devpath_real)) != 0)
                        return NULL;
-
        }
 
        list_for_each_entry(sysdev_loop, &sysfs_dev_list, node) {
                if (strcmp(sysdev_loop->dev.devpath, devpath_real) == 0) {
                        dbg("found dev in cache '%s'", sysdev_loop->dev.devpath);
-                               dev = &sysdev_loop->dev;
+                       dev = &sysdev_loop->dev;
                }
        }
+
        if(!dev) {
                /* it is a new device */
                dbg("new device '%s'", devpath_real);
@@ -217,33 +234,25 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
                pos = strrchr(link_target, '/');
                if (pos != NULL)
                        strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
-       } else if (strncmp(dev->devpath, "/class/", 7) == 0) {
-               /* get subsystem from class dir */
-               strlcpy(dev->subsystem, &dev->devpath[7], sizeof(dev->subsystem));
-               pos = strchr(dev->subsystem, '/');
-               if (pos != NULL)
-                       pos[0] = '\0';
-               else
-                       dev->subsystem[0] = '\0';
-       } else if (strncmp(dev->devpath, "/block/", 7) == 0) {
-               strlcpy(dev->subsystem, "block", sizeof(dev->subsystem));
-       } else if (strncmp(dev->devpath, "/devices/", 9) == 0) {
-               /* get subsystem from "bus" link */
-               strlcpy(link_path, sysfs_path, sizeof(link_path));
-               strlcat(link_path, dev->devpath, sizeof(link_path));
-               strlcat(link_path, "/bus", sizeof(link_path));
-               len = readlink(link_path, link_target, sizeof(link_target));
-               if (len > 0) {
-                       link_target[len] = '\0';
-                       dbg("bus link '%s' points to '%s'", link_path, link_target);
-                       pos = strrchr(link_target, '/');
-                       if (pos != NULL)
-                               strlcpy(dev->subsystem, &pos[1], sizeof(dev->subsystem));
-               }
        } else if (strstr(dev->devpath, "/drivers/") != NULL) {
                strlcpy(dev->subsystem, "drivers", sizeof(dev->subsystem));
        } else if (strncmp(dev->devpath, "/module/", 8) == 0) {
                strlcpy(dev->subsystem, "module", sizeof(dev->subsystem));
+       } else if (strncmp(dev->devpath, "/subsystem/", 11) == 0) {
+               pos = strrchr(dev->devpath, '/');
+               if (pos == &dev->devpath[10])
+                       strlcpy(dev->subsystem, "subsystem",
+                               sizeof(dev->subsystem));
+       } else if (strncmp(dev->devpath, "/class/", 7) == 0) {
+               pos = strrchr(dev->devpath, '/');
+               if (pos == &dev->devpath[6])
+                       strlcpy(dev->subsystem, "subsystem",
+                               sizeof(dev->subsystem));
+       } else if (strncmp(dev->devpath, "/bus/", 5) == 0) {
+               pos = strrchr(dev->devpath, '/');
+               if (pos == &dev->devpath[4])
+                       strlcpy(dev->subsystem, "subsystem",
+                               sizeof(dev->subsystem));
        }
 
        /* get driver name */
@@ -258,6 +267,7 @@ struct sysfs_device *sysfs_device_get(const char *devpath)
                if (pos != NULL)
                        strlcpy(dev->driver, &pos[1], sizeof(dev->driver));
        }
+
        return dev;
 }
 
@@ -272,13 +282,6 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
        if (dev->parent != NULL)
                return dev->parent;
 
-       /* requesting a parent is only valid for devices */
-       if ((strncmp(dev->devpath, "/devices/", 9) != 0) &&
-           (strncmp(dev->devpath, "/subsystem/", 11) != 0) &&
-           (strncmp(dev->devpath, "/class/", 7) != 0) &&
-           (strncmp(dev->devpath, "/block/", 7) != 0))
-               return NULL;
-
        strlcpy(parent_devpath, dev->devpath, sizeof(parent_devpath));
        dbg("'%s'", parent_devpath);
 
@@ -288,20 +291,6 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
                return NULL;
        pos[0] = '\0';
 
-       /* are we at the top level of /devices */
-       if (strcmp(parent_devpath, "/devices") == 0) {
-               dbg("/devices top level");
-               return NULL;
-       }
-
-       /* at the subsystems top level we want to follow the old-style "device" link */
-       if (strncmp(parent_devpath, "/subsystem", 10) == 0) {
-               pos = strrchr(parent_devpath, '/');
-               if (pos == &parent_devpath[10] || pos == parent_devpath || strcmp(pos, "/devices") == 0) {
-                       dbg("/subsystem top level, look for device link");
-                       goto device_link;
-               }
-       }
        if (strncmp(parent_devpath, "/class", 6) == 0) {
                pos = strrchr(parent_devpath, '/');
                if (pos == &parent_devpath[6] || pos == parent_devpath) {
@@ -314,6 +303,11 @@ struct sysfs_device *sysfs_device_get_parent(struct sysfs_device *dev)
                goto device_link;
        }
 
+       /* are we at the top level? */
+       pos = strrchr(parent_devpath, '/');
+       if (pos == NULL || pos == parent_devpath)
+               return NULL;
+
        /* get parent and remember it */
        dev->parent = sysfs_device_get(parent_devpath);
        return dev->parent;
@@ -375,6 +369,8 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
 
        dbg("open '%s'/'%s'", devpath, attr_name);
        sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
+       if(sysfs_len >= sizeof(path_full))
+               sysfs_len = sizeof(path_full) - 1;
        path = &path_full[sysfs_len];
        strlcat(path_full, devpath, sizeof(path_full));
        strlcat(path_full, "/", sizeof(path_full));
@@ -419,8 +415,10 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
                        link_target[len] = '\0';
                        pos = strrchr(link_target, '/');
                        if (pos != NULL) {
-                               dbg("cache '%s' with link value '%s'", path_full, value);
-                               strlcpy(attr->value_local, &pos[1], sizeof(attr->value_local));
+                               dbg("cache '%s' with link value '%s'",
+                                   path_full, value);
+                               strlcpy(attr->value_local, &pos[1],
+                                       sizeof(attr->value_local));
                                attr->value = attr->value_local;
                        }
                }
@@ -438,7 +436,8 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
        /* read attribute value */
        fd = open(path_full, O_RDONLY);
        if (fd < 0) {
-               dbg("attribute '%s' does not exist", path_full);
+               dbg("attribute '%s' can not be opened: %s",
+                   path_full, strerror(errno));
                goto out;
        }
        size = read(fd, value, sizeof(value));
@@ -458,3 +457,95 @@ char *sysfs_attr_get_value(const char *devpath, const char *attr_name)
 out:
        return attr->value;
 }
+
+int sysfs_lookup_devpath_by_subsys_id(char *devpath_full, size_t len,
+                                     const char *subsystem, const char *id)
+{
+       size_t sysfs_len;
+       char path_full[PATH_SIZE];
+       char *path;
+       struct stat statbuf;
+
+       sysfs_len = strlcpy(path_full, sysfs_path, sizeof(path_full));
+       path = &path_full[sysfs_len];
+
+       if (strcmp(subsystem, "subsystem") == 0) {
+               strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+               strlcat(path, id, sizeof(path_full) - sysfs_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+
+               strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+               strlcat(path, id, sizeof(path_full) - sysfs_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+               goto out;
+
+               strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
+               strlcat(path, id, sizeof(path_full) - sysfs_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+       }
+
+       if (strcmp(subsystem, "module") == 0) {
+               strlcpy(path, "/module/", sizeof(path_full) - sysfs_len);
+               strlcat(path, id, sizeof(path_full) - sysfs_len);
+               if (stat(path_full, &statbuf) == 0)
+                       goto found;
+               goto out;
+       }
+
+       if (strcmp(subsystem, "drivers") == 0) {
+               char subsys[NAME_SIZE];
+               char *driver;
+
+               strlcpy(subsys, id, sizeof(subsys));
+               driver = strchr(subsys, ':');
+               if (driver != NULL) {
+                       driver[0] = '\0';
+                       driver = &driver[1];
+                       strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+                       strlcat(path, subsys, sizeof(path_full) - sysfs_len);
+                       strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
+                       strlcat(path, driver, sizeof(path_full) - sysfs_len);
+                       if (stat(path_full, &statbuf) == 0)
+                               goto found;
+
+                       strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+                       strlcat(path, subsys, sizeof(path_full) - sysfs_len);
+                       strlcat(path, "/drivers/", sizeof(path_full) - sysfs_len);
+                       strlcat(path, driver, sizeof(path_full) - sysfs_len);
+                       if (stat(path_full, &statbuf) == 0)
+                               goto found;
+               }
+               goto out;
+       }
+
+       strlcpy(path, "/subsystem/", sizeof(path_full) - sysfs_len);
+       strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+       strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
+       strlcat(path, id, sizeof(path_full) - sysfs_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+
+       strlcpy(path, "/bus/", sizeof(path_full) - sysfs_len);
+       strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+       strlcat(path, "/devices/", sizeof(path_full) - sysfs_len);
+       strlcat(path, id, sizeof(path_full) - sysfs_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+
+       strlcpy(path, "/class/", sizeof(path_full) - sysfs_len);
+       strlcat(path, subsystem, sizeof(path_full) - sysfs_len);
+       strlcat(path, "/", sizeof(path_full) - sysfs_len);
+       strlcat(path, id, sizeof(path_full) - sysfs_len);
+       if (stat(path_full, &statbuf) == 0)
+               goto found;
+out:
+       return 0;
+found:
+       if (S_ISLNK(statbuf.st_mode))
+               sysfs_resolve_link(path, sizeof(path_full) - sysfs_len);
+       strlcpy(devpath_full, path, len);
+       return 1;
+}