sysfs_is_multipathed reads the wwid of the dm device holding a path to
check if its a multipath device. Add code to optinally set pp->wwid to
that wwid. This will be used by a future patch.
Reviewed-by: Martin Wilck <mwilck@xxxxxxxx>
Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
---
libmultipath/sysfs.c | 24 +++++++++++++++++++-----
libmultipath/sysfs.h | 2 +-
multipath/main.c | 7 ++++---
3 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c
index 62ec2ed7..12a82d95 100644
--- a/libmultipath/sysfs.c
+++ b/libmultipath/sysfs.c
@@ -295,7 +295,7 @@ static int select_dm_devs(const struct dirent *di)
return fnmatch("dm-*", di->d_name, FNM_FILE_NAME) == 0;
}
-bool sysfs_is_multipathed(const struct path *pp)
+bool sysfs_is_multipathed(struct path *pp, bool set_wwid)
{
char pathbuf[PATH_MAX];
struct scandir_result sr;
@@ -325,7 +325,7 @@ bool sysfs_is_multipathed(const struct path *pp)
for (i = 0; i < r && !found; i++) {
long fd;
int nr;
- char uuid[6];
+ char uuid[WWID_SIZE + UUID_PREFIX_LEN];
if (safe_snprintf(pathbuf + n, sizeof(pathbuf) - n,
"/%s/dm/uuid", di[i]->d_name))
@@ -339,12 +339,26 @@ bool sysfs_is_multipathed(const struct path *pp)
pthread_cleanup_push(close_fd, (void *)fd);
nr = read(fd, uuid, sizeof(uuid));
- if (nr == sizeof(uuid) && !memcmp(uuid, "mpath-", sizeof(uuid)))
+ if (nr > (int)UUID_PREFIX_LEN &&
+ !memcmp(uuid, UUID_PREFIX, UUID_PREFIX_LEN))
found = true;
else if (nr < 0) {
- condlog(1, "%s: error reading from %s: %s",
- __func__, pathbuf, strerror(errno));
+ condlog(1, "%s: error reading from %s: %m",
+ __func__, pathbuf);
}
+ if (found && set_wwid) {
+ nr -= UUID_PREFIX_LEN;
+ memcpy(pp->wwid, uuid + UUID_PREFIX_LEN, nr);
+ if (nr == WWID_SIZE) {
+ condlog(4, "%s: overflow while reading from %s",
+ __func__, pathbuf);
+ pp->wwid[0] = '\0';
+ } else {
+ pp->wwid[nr] = '\0';
+ strchop(pp->wwid);
+ }
+ }
+
pthread_cleanup_pop(1);
}
pthread_cleanup_pop(1);
diff --git a/libmultipath/sysfs.h b/libmultipath/sysfs.h
index 9ae30b39..72b39ab2 100644
--- a/libmultipath/sysfs.h
+++ b/libmultipath/sysfs.h
@@ -14,5 +14,5 @@ ssize_t sysfs_bin_attr_get_value(struct udev_device *dev, const char *attr_name,
unsigned char * value, size_t value_len);
int sysfs_get_size (struct path *pp, unsigned long long * size);
int sysfs_check_holders(char * check_devt, char * new_devt);
-bool sysfs_is_multipathed(const struct path *pp);
+bool sysfs_is_multipathed(struct path *pp, bool set_wwid);
#endif
diff --git a/multipath/main.c b/multipath/main.c
index cf9d2a28..545ead87 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -638,7 +638,8 @@ configure (struct config *conf, enum mpath_cmds cmd,
* Shortcut for find_multipaths smart:
* Quick check if path is already multipathed.
*/
- if (sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0))) {
+ if (sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0),
+ false)) {
r = RTVL_YES;
goto print_valid;
}
@@ -747,8 +748,8 @@ configure (struct config *conf, enum mpath_cmds cmd,
/*
* Check if we raced with multipathd
*/
- r = sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0)) ?
- RTVL_YES : RTVL_NO;
+ r = sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0),
+ false) ? RTVL_YES : RTVL_NO;
}
goto print_valid;
}
--
2.17.2
--
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