From: Robert Milasan <rmilasan@suse.cz>
To: linux-hotplug@vger.kernel.org
Subject: Re-enable by-path links for ata device
Date: Thu, 02 Aug 2012 18:31:26 +0000 [thread overview]
Message-ID: <20120802203126.71a8f2af@coolcat.suse.cz> (raw)
Hello, just created a patch for openSUSE to re-enable by-path links for
ata devices. The patch is based on handle_scsi_default function, but
instead of using "host{NUMBER}", but "ata{NUMBER}" and it works almost
the same as for scsi devices.
The patch is not the best or the cleanest, but it works.
Index: udev-182/src/udev-builtin-path_id.c
=================================--- udev-182.orig/src/udev-builtin-path_id.c
+++ udev-182/src/udev-builtin-path_id.c
@@ -286,6 +286,85 @@ out:
return hostdev;
}
+static struct udev_device *handle_ata(struct udev_device *parent, char **path)
+{
+ struct udev_device *hostdev;
+ int host, bus, target, lun;
+ const char *name;
+ char *base;
+ char *pos;
+ DIR *dir;
+ struct dirent *dent;
+ int basenum, len;
+
+ hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
+ if (hostdev = NULL)
+ return NULL;
+
+ name = udev_device_get_sysname(parent);
+ if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
+ return NULL;
+
+ /* rebase ata offset to get the local relative number */
+ basenum = -1;
+ base = strdup(udev_device_get_syspath(hostdev));
+ if (base = NULL)
+ return NULL;
+ pos = strrchr(base, '/');
+ if (pos = NULL) {
+ parent = NULL;
+ goto out;
+ }
+ pos[0] = '\0';
+ len = strlen(base) - 5;
+ if (len <= 0) {
+ parent = NULL;
+ goto out;
+ }
+ base[len] = '\0';
+ dir = opendir(base);
+ if (dir = NULL) {
+ parent = NULL;
+ goto out;
+ }
+ for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+ char *rest;
+ int i;
+
+ if (dent->d_name[0] = '.')
+ continue;
+ if (dent->d_type != DT_DIR && dent->d_type != DT_LNK)
+ continue;
+ if (strncmp(dent->d_name, "ata", 3) != 0)
+ continue;
+ i = strtoul(&dent->d_name[3], &rest, 10);
+
+ /* ata devices start with 1, so decrease by 1 if i is bigger then 0 */
+ if (i > 0)
+ i--;
+ if (rest[0] != '\0')
+ continue;
+ /*
+ * find the smallest number; the host really needs to export its
+ * own instance number per parent device; relying on the global host
+ * enumeration and plainly rebasing the numbers sounds unreliable
+ */
+ if (basenum = -1 || i < basenum)
+ basenum = i;
+ }
+ closedir(dir);
+ if (basenum = -1) {
+ parent = NULL;
+ goto out;
+ }
+ host -= basenum;
+
+ path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
+out:
+ free(base);
+ return hostdev;
+}
+
static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
{
const char *devtype;
@@ -322,16 +401,8 @@ static struct udev_device *handle_scsi(s
goto out;
}
- /*
- * We do not support the ATA transport class, it creates duplicated link
- * names as the fake SCSI host adapters are all separated, they are all
- * re-based as host = 0. ATA should just stop faking two duplicated
- * hierarchies for a single topology and leave the SCSI stuff alone;
- * until that happens, there are no by-path/ links for ATA devices behind
- * an ATA transport class.
- */
if (strstr(name, "/ata") != NULL) {
- parent = NULL;
+ parent = handle_ata(parent, path);
goto out;
}
NOTE: The patch is for udev 182, but its easy to adapt this to systemd
187.
next reply other threads:[~2012-08-02 18:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-02 18:31 Robert Milasan [this message]
2012-08-03 8:44 ` Re-enable by-path links for ata device Kay Sievers
2012-08-03 9:31 ` Robert Milasan
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