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-rw-r--r--lib/libzutil/os/linux/zutil_device_path_os.c252
1 files changed, 142 insertions, 110 deletions
diff --git a/lib/libzutil/os/linux/zutil_device_path_os.c b/lib/libzutil/os/linux/zutil_device_path_os.c
index 36331fd72..1f767bb7a 100644
--- a/lib/libzutil/os/linux/zutil_device_path_os.c
+++ b/lib/libzutil/os/linux/zutil_device_path_os.c
@@ -155,14 +155,123 @@ zfs_strip_path(char *path)
}
/*
+ * Given a dev name like "sda", return the full enclosure sysfs path to
+ * the disk. You can also pass in the name with "/dev" prepended
+ * to it (like /dev/sda).
+ *
+ * For example, disk "sda" in enclosure slot 1:
+ * dev: "sda"
+ * returns: "/sys/class/enclosure/1:0:3:0/Slot 1"
+ *
+ * 'dev' must be a non-devicemapper device.
+ *
+ * Returned string must be freed.
+ */
+char *
+zfs_get_enclosure_sysfs_path(const char *dev_name)
+{
+ DIR *dp = NULL;
+ struct dirent *ep;
+ char buf[MAXPATHLEN];
+ char *tmp1 = NULL;
+ char *tmp2 = NULL;
+ char *tmp3 = NULL;
+ char *path = NULL;
+ size_t size;
+ int tmpsize;
+
+ if (dev_name == NULL)
+ return (NULL);
+
+ /* If they preface 'dev' with a path (like "/dev") then strip it off */
+ tmp1 = strrchr(dev_name, '/');
+ if (tmp1 != NULL)
+ dev_name = tmp1 + 1; /* +1 since we want the chr after '/' */
+
+ tmpsize = asprintf(&tmp1, "/sys/block/%s/device", dev_name);
+ if (tmpsize == -1 || tmp1 == NULL) {
+ tmp1 = NULL;
+ goto end;
+ }
+
+ dp = opendir(tmp1);
+ if (dp == NULL) {
+ tmp1 = NULL; /* To make free() at the end a NOP */
+ goto end;
+ }
+
+ /*
+ * Look though all sysfs entries in /sys/block/<dev>/device for
+ * the enclosure symlink.
+ */
+ while ((ep = readdir(dp))) {
+ /* Ignore everything that's not our enclosure_device link */
+ if (strstr(ep->d_name, "enclosure_device") == NULL)
+ continue;
+
+ if (asprintf(&tmp2, "%s/%s", tmp1, ep->d_name) == -1 ||
+ tmp2 == NULL)
+ break;
+
+ size = readlink(tmp2, buf, sizeof (buf));
+
+ /* Did readlink fail or crop the link name? */
+ if (size == -1 || size >= sizeof (buf)) {
+ free(tmp2);
+ tmp2 = NULL; /* To make free() at the end a NOP */
+ break;
+ }
+
+ /*
+ * We got a valid link. readlink() doesn't terminate strings
+ * so we have to do it.
+ */
+ buf[size] = '\0';
+
+ /*
+ * Our link will look like:
+ *
+ * "../../../../port-11:1:2/..STUFF../enclosure/1:0:3:0/SLOT 1"
+ *
+ * We want to grab the "enclosure/1:0:3:0/SLOT 1" part
+ */
+ tmp3 = strstr(buf, "enclosure");
+ if (tmp3 == NULL)
+ break;
+
+ if (asprintf(&path, "/sys/class/%s", tmp3) == -1) {
+ /* If asprintf() fails, 'path' is undefined */
+ path = NULL;
+ break;
+ }
+
+ if (path == NULL)
+ break;
+ }
+
+end:
+ free(tmp2);
+ free(tmp1);
+
+ if (dp != NULL)
+ closedir(dp);
+
+ return (path);
+}
+
+/*
* Allocate and return the underlying device name for a device mapper device.
- * If a device mapper device maps to multiple devices, return the first device.
*
* For example, dm_name = "/dev/dm-0" could return "/dev/sda". Symlinks to a
* DM device (like /dev/disk/by-vdev/A0) are also allowed.
*
- * Returns device name, or NULL on error or no match. If dm_name is not a DM
- * device then return NULL.
+ * If the DM device has multiple underlying devices (like with multipath
+ * DM devices), then favor underlying devices that have a symlink back to their
+ * back to their enclosure device in sysfs. This will be useful for the
+ * zedlet scripts that toggle the fault LED.
+ *
+ * Returns an underlying device name, or NULL on error or no match. If dm_name
+ * is not a DM device then return NULL.
*
* NOTE: The returned name string must be *freed*.
*/
@@ -176,6 +285,8 @@ dm_get_underlying_path(const char *dm_name)
char *path = NULL;
char *dev_str;
int size;
+ char *first_path = NULL;
+ char *enclosure_path;
if (dm_name == NULL)
return (NULL);
@@ -204,13 +315,27 @@ dm_get_underlying_path(const char *dm_name)
goto end;
/*
- * Return first entry (that isn't itself a directory) in the
- * directory containing device-mapper dependent (underlying)
- * devices.
+ * A device-mapper device can have multiple paths to it (multipath).
+ * Favor paths that have a symlink back to their enclosure device.
+ * We have to do this since some enclosures may only provide a symlink
+ * back for one underlying path to a disk and not the other.
+ *
+ * If no paths have links back to their enclosure, then just return the
+ * first path.
*/
while ((ep = readdir(dp))) {
if (ep->d_type != DT_DIR) { /* skip "." and ".." dirs */
+ if (!first_path)
+ first_path = strdup(ep->d_name);
+
+ enclosure_path =
+ zfs_get_enclosure_sysfs_path(ep->d_name);
+
+ if (!enclosure_path)
+ continue;
+
size = asprintf(&path, "/dev/%s", ep->d_name);
+ free(enclosure_path);
break;
}
}
@@ -220,6 +345,17 @@ end:
closedir(dp);
free(tmp);
free(realp);
+
+ if (!path) {
+ /*
+ * None of the underlying paths had a link back to their
+ * enclosure devices. Throw up out hands and return the first
+ * underlying path.
+ */
+ size = asprintf(&path, "/dev/%s", first_path);
+ }
+
+ free(first_path);
return (path);
}
@@ -331,110 +467,6 @@ zfs_get_underlying_path(const char *dev_name)
return (name);
}
-/*
- * Given a dev name like "sda", return the full enclosure sysfs path to
- * the disk. You can also pass in the name with "/dev" prepended
- * to it (like /dev/sda).
- *
- * For example, disk "sda" in enclosure slot 1:
- * dev: "sda"
- * returns: "/sys/class/enclosure/1:0:3:0/Slot 1"
- *
- * 'dev' must be a non-devicemapper device.
- *
- * Returned string must be freed.
- */
-char *
-zfs_get_enclosure_sysfs_path(const char *dev_name)
-{
- DIR *dp = NULL;
- struct dirent *ep;
- char buf[MAXPATHLEN];
- char *tmp1 = NULL;
- char *tmp2 = NULL;
- char *tmp3 = NULL;
- char *path = NULL;
- size_t size;
- int tmpsize;
-
- if (dev_name == NULL)
- return (NULL);
-
- /* If they preface 'dev' with a path (like "/dev") then strip it off */
- tmp1 = strrchr(dev_name, '/');
- if (tmp1 != NULL)
- dev_name = tmp1 + 1; /* +1 since we want the chr after '/' */
-
- tmpsize = asprintf(&tmp1, "/sys/block/%s/device", dev_name);
- if (tmpsize == -1 || tmp1 == NULL) {
- tmp1 = NULL;
- goto end;
- }
-
- dp = opendir(tmp1);
- if (dp == NULL) {
- tmp1 = NULL; /* To make free() at the end a NOP */
- goto end;
- }
-
- /*
- * Look though all sysfs entries in /sys/block/<dev>/device for
- * the enclosure symlink.
- */
- while ((ep = readdir(dp))) {
- /* Ignore everything that's not our enclosure_device link */
- if (strstr(ep->d_name, "enclosure_device") == NULL)
- continue;
-
- if (asprintf(&tmp2, "%s/%s", tmp1, ep->d_name) == -1 ||
- tmp2 == NULL)
- break;
-
- size = readlink(tmp2, buf, sizeof (buf));
-
- /* Did readlink fail or crop the link name? */
- if (size == -1 || size >= sizeof (buf)) {
- free(tmp2);
- tmp2 = NULL; /* To make free() at the end a NOP */
- break;
- }
-
- /*
- * We got a valid link. readlink() doesn't terminate strings
- * so we have to do it.
- */
- buf[size] = '\0';
-
- /*
- * Our link will look like:
- *
- * "../../../../port-11:1:2/..STUFF../enclosure/1:0:3:0/SLOT 1"
- *
- * We want to grab the "enclosure/1:0:3:0/SLOT 1" part
- */
- tmp3 = strstr(buf, "enclosure");
- if (tmp3 == NULL)
- break;
-
- if (asprintf(&path, "/sys/class/%s", tmp3) == -1) {
- /* If asprintf() fails, 'path' is undefined */
- path = NULL;
- break;
- }
-
- if (path == NULL)
- break;
- }
-
-end:
- free(tmp2);
- free(tmp1);
-
- if (dp != NULL)
- closedir(dp);
-
- return (path);
-}
#ifdef HAVE_LIBUDEV
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 05:48:21 +0000