[v3,2/4] libmultipath: add helper function check_path_wwid_change

Commit Message

Benjamin Marzinski April 2, 2025, 11:13 p.m. UTC

Wrap some code from select_recheck_wwid() in a helper function. A future
patch will call this code from a different function.

Signed-off-by: Benjamin Marzinski <[e-mail]>
---
 libmultipath/discovery.c | 12 +++++++++++-
 libmultipath/discovery.h |  2 +-
 libmultipath/propsel.c   |  4 +---
 3 files changed, 13 insertions(+), 5 deletions(-)

Patch

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index 846101d0..c4bc6df6 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -2245,7 +2245,7 @@  static ssize_t uid_fallback(struct path *pp, int path_state,
 	return len;
 }
 
-bool has_uid_fallback(struct path *pp)
+static bool has_uid_fallback(const struct path *pp)
 {
 	/*
 	 * Falling back to direct WWID determination is dangerous
@@ -2266,6 +2266,16 @@  bool has_uid_fallback(struct path *pp)
 		  !strcmp(pp->uid_attribute, ""))));
 }
 
+bool can_recheck_wwid(const struct path *pp)
+{
+	/*
+	 * check_path_wwid_change() only works for scsi devices, and it
+	 * is only guaranteed to give the same WWID if the path uses
+	 * the default uid_attribute
+	 */
+	return (pp->bus == SYSFS_BUS_SCSI && has_uid_fallback(pp));
+}
+
 int
 get_uid (struct path * pp, int path_state, struct udev_device *udev,
 	 int allow_fallback)
diff --git a/libmultipath/discovery.h b/libmultipath/discovery.h
index 2b39eb04..2ef1d94b 100644
--- a/libmultipath/discovery.h
+++ b/libmultipath/discovery.h
@@ -55,7 +55,7 @@  ssize_t sysfs_get_inquiry(struct udev_device *udev,
 			  unsigned char *buff, size_t len);
 int sysfs_get_asymmetric_access_state(struct path *pp,
 				      char *buff, int buflen);
-bool has_uid_fallback(struct path *pp);
+bool can_recheck_wwid(const struct path *pp);
 int get_uid(struct path * pp, int path_state, struct udev_device *udev,
 	    int allow_fallback);
 bool is_vpd_page_supported(int fd, int pg);
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 664e62fc..367a9839 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -739,9 +739,7 @@  int select_recheck_wwid(struct config *conf, struct path * pp)
 	pp_set_conf(recheck_wwid);
 	pp_set_default(recheck_wwid, DEFAULT_RECHECK_WWID);
 out:
-	if (pp->recheck_wwid == RECHECK_WWID_ON &&
-	    (pp->bus != SYSFS_BUS_SCSI ||
-	     !has_uid_fallback(pp))) {
+	if (pp->recheck_wwid == RECHECK_WWID_ON && !can_recheck_wwid(pp)) {
 		pp->recheck_wwid = RECHECK_WWID_OFF;
 		origin = "(setting: unsupported by device type/config)";
 	}