This code pulls the multipath path validation code out of configure(),
and puts it into its own function, check_path_valid(). This function
calls a new libmultipath function, is_path_valid() to check just path
requested. This seperation exists so that is_path_valid() can be reused
by future code. This code will give almost the same answer as the
existing code, with the exception that now, if a device is currently
multipathed, it will always be a valid multipath path.

Reviewed-by: Martin Wilck <mwi...@suse.com>
Signed-off-by: Benjamin Marzinski <bmarz...@redhat.com>
---
 libmultipath/Makefile    |   2 +-
 libmultipath/devmapper.c |  45 ++++++
 libmultipath/devmapper.h |   1 +
 libmultipath/structs.h   |  24 +---
 libmultipath/valid.c     | 118 ++++++++++++++++
 libmultipath/valid.h     |  42 ++++++
 libmultipath/wwids.c     |  10 +-
 multipath/main.c         | 296 +++++++++++++++++----------------------
 8 files changed, 343 insertions(+), 195 deletions(-)
 create mode 100644 libmultipath/valid.c
 create mode 100644 libmultipath/valid.h

diff --git a/libmultipath/Makefile b/libmultipath/Makefile
index f19b7ad2..e5dac5ea 100644
--- a/libmultipath/Makefile
+++ b/libmultipath/Makefile
@@ -48,7 +48,7 @@ OBJS = memory.o parser.o vector.o devmapper.o callout.o \
        log.o configure.o structs_vec.o sysfs.o prio.o checkers.o \
        lock.o file.o wwids.o prioritizers/alua_rtpg.o prkey.o \
        io_err_stat.o dm-generic.o generic.o foreign.o nvme-lib.o \
-       libsg.o
+       libsg.o valid.o
 
 all: $(LIBS)
 
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 7ed494a1..27d52398 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -770,6 +770,51 @@ out:
        return r;
 }
 
+/*
+ * Return
+ *   1 : map with uuid exists
+ *   0 : map with uuid doesn't exist
+ *  -1 : error
+ */
+int
+dm_map_present_by_uuid(const char *uuid)
+{
+       struct dm_task *dmt;
+       struct dm_info info;
+       char prefixed_uuid[WWID_SIZE + UUID_PREFIX_LEN];
+       int r = -1;
+
+       if (!uuid || uuid[0] == '\0')
+               return 0;
+
+       if (safe_sprintf(prefixed_uuid, UUID_PREFIX "%s", uuid))
+               goto out;
+
+       if (!(dmt = dm_task_create(DM_DEVICE_INFO)))
+               goto out;
+
+       dm_task_no_open_count(dmt);
+
+       if (!dm_task_set_uuid(dmt, prefixed_uuid))
+               goto out_task;
+
+       if (!dm_task_run(dmt))
+               goto out_task;
+
+       if (!dm_task_get_info(dmt, &info))
+               goto out_task;
+
+       r = !!info.exists;
+
+out_task:
+       dm_task_destroy(dmt);
+out:
+       if (r < 0)
+               condlog(3, "%s: dm command failed in %s: %s", uuid,
+                       __FUNCTION__, strerror(errno));
+       return r;
+}
+
 static int
 dm_dev_t (const char * mapname, char * dev_t, int len)
 {
diff --git a/libmultipath/devmapper.h b/libmultipath/devmapper.h
index 17fc9faf..5ed7edc5 100644
--- a/libmultipath/devmapper.h
+++ b/libmultipath/devmapper.h
@@ -39,6 +39,7 @@ int dm_simplecmd_noflush (int, const char *, uint16_t);
 int dm_addmap_create (struct multipath *mpp, char *params);
 int dm_addmap_reload (struct multipath *mpp, char *params, int flush);
 int dm_map_present (const char *);
+int dm_map_present_by_uuid(const char *uuid);
 int dm_get_map(const char *, unsigned long long *, char *);
 int dm_get_status(const char *, char *);
 int dm_type(const char *, char *);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index 9bd39eb1..d69bc2e9 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -101,29 +101,13 @@ enum yes_no_undef_states {
        YNU_YES,
 };
 
-#define _FIND_MULTIPATHS_F (1 << 1)
-#define _FIND_MULTIPATHS_I (1 << 2)
-#define _FIND_MULTIPATHS_N (1 << 3)
-/*
- * _FIND_MULTIPATHS_F must have the same value as YNU_YES.
- * Generate a compile time error if that isn't the case.
- */
-extern char ___error1___[-(_FIND_MULTIPATHS_F != YNU_YES)];
-
-#define find_multipaths_on(conf) \
-       (!!((conf)->find_multipaths & _FIND_MULTIPATHS_F))
-#define ignore_wwids_on(conf) \
-       (!!((conf)->find_multipaths & _FIND_MULTIPATHS_I))
-#define ignore_new_devs_on(conf) \
-       (!!((conf)->find_multipaths & _FIND_MULTIPATHS_N))
-
 enum find_multipaths_states {
        FIND_MULTIPATHS_UNDEF = YNU_UNDEF,
        FIND_MULTIPATHS_OFF = YNU_NO,
-       FIND_MULTIPATHS_ON = _FIND_MULTIPATHS_F,
-       FIND_MULTIPATHS_GREEDY = _FIND_MULTIPATHS_I,
-       FIND_MULTIPATHS_SMART = _FIND_MULTIPATHS_F|_FIND_MULTIPATHS_I,
-       FIND_MULTIPATHS_STRICT = _FIND_MULTIPATHS_F|_FIND_MULTIPATHS_N,
+       FIND_MULTIPATHS_ON = YNU_YES,
+       FIND_MULTIPATHS_GREEDY,
+       FIND_MULTIPATHS_SMART,
+       FIND_MULTIPATHS_STRICT,
        __FIND_MULTIPATHS_LAST,
 };
 
diff --git a/libmultipath/valid.c b/libmultipath/valid.c
new file mode 100644
index 00000000..456b1f6e
--- /dev/null
+++ b/libmultipath/valid.c
@@ -0,0 +1,118 @@
+/*
+  Copyright (c) 2020 Benjamin Marzinski, IBM
+
+  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; either version 2
+  of the License, or (at your option) any later version.
+
+  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, see <https://www.gnu.org/licenses/>.
+ */
+#include <stddef.h>
+#include <errno.h>
+#include <libudev.h>
+
+#include "vector.h"
+#include "config.h"
+#include "debug.h"
+#include "util.h"
+#include "devmapper.h"
+#include "discovery.h"
+#include "wwids.h"
+#include "sysfs.h"
+#include "blacklist.h"
+#include "mpath_cmd.h"
+#include "valid.h"
+
+int
+is_path_valid(const char *name, struct config *conf, struct path *pp,
+             bool check_multipathd)
+{
+       int r;
+       int fd;
+
+       if (!pp || !name || !conf)
+               return PATH_IS_ERROR;
+
+       if (conf->find_multipaths <= FIND_MULTIPATHS_UNDEF ||
+           conf->find_multipaths >= __FIND_MULTIPATHS_LAST)
+               return PATH_IS_ERROR;
+
+       if (safe_sprintf(pp->dev, "%s", name))
+               return PATH_IS_ERROR;
+
+       if (sysfs_is_multipathed(pp, true)) {
+               if (pp->wwid[0] == '\0')
+                       return PATH_IS_ERROR;
+               return PATH_IS_VALID_NO_CHECK;
+       }
+
+       /*
+        * "multipath -u" may be run before the daemon is started. In this
+        * case, systemd might own the socket but might delay multipathd
+        * startup until some other unit (udev settle!)  has finished
+        * starting. With many LUNs, the listen backlog may be exceeded, which
+        * would cause connect() to block. This causes udev workers calling
+        * "multipath -u" to hang, and thus creates a deadlock, until "udev
+        * settle" times out.  To avoid this, call connect() in non-blocking
+        * mode here, and take EAGAIN as indication for a filled-up systemd
+        * backlog.
+        */
+
+       if (check_multipathd) {
+               fd = __mpath_connect(1);
+               if (fd < 0) {
+                       if (errno != EAGAIN && !systemd_service_enabled(name)) {
+                               condlog(3, "multipathd not running or enabled");
+                               return PATH_IS_NOT_VALID;
+                       }
+               } else
+                       mpath_disconnect(fd);
+       }
+
+       pp->udev = udev_device_new_from_subsystem_sysname(udev, "block", name);
+       if (!pp->udev)
+               return PATH_IS_ERROR;
+
+       r = pathinfo(pp, conf, DI_SYSFS | DI_WWID | DI_BLACKLIST);
+       if (r == PATHINFO_SKIPPED)
+               return PATH_IS_NOT_VALID;
+       else if (r)
+               return PATH_IS_ERROR;
+
+       if (pp->wwid[0] == '\0')
+               return PATH_IS_NOT_VALID;
+
+       if (pp->udev && pp->uid_attribute &&
+           filter_property(conf, pp->udev, 3, pp->uid_attribute) > 0)
+               return PATH_IS_NOT_VALID;
+
+       r = is_failed_wwid(pp->wwid);
+       if (r != WWID_IS_NOT_FAILED) {
+               if (r == WWID_IS_FAILED)
+                       return PATH_IS_NOT_VALID;
+               return PATH_IS_ERROR;
+       }
+
+       if (conf->find_multipaths == FIND_MULTIPATHS_GREEDY)
+               return PATH_IS_VALID;
+
+       if (check_wwids_file(pp->wwid, 0) == 0)
+               return PATH_IS_VALID_NO_CHECK;
+
+       if (dm_map_present_by_uuid(pp->wwid) == 1)
+               return PATH_IS_VALID;
+
+       /* all these act like FIND_MULTIPATHS_STRICT for finding if a
+        * path is valid */
+       if (conf->find_multipaths != FIND_MULTIPATHS_SMART)
+               return PATH_IS_NOT_VALID;
+
+       return PATH_IS_MAYBE_VALID;
+}
diff --git a/libmultipath/valid.h b/libmultipath/valid.h
new file mode 100644
index 00000000..ce1c7cbf
--- /dev/null
+++ b/libmultipath/valid.h
@@ -0,0 +1,42 @@
+/*
+  Copyright (c) 2020 Benjamin Marzinski, IBM
+
+  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; either version 2
+  of the License, or (at your option) any later version.
+
+  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, see <https://www.gnu.org/licenses/>.
+ */
+#ifndef _VALID_H
+#define _VALID_H
+
+/*
+ * PATH_IS_VALID_NO_CHECK is returned when multipath should claim
+ * the path, regardless of whether is has been released to systemd
+ * already.
+ * PATH_IS_VALID is returned by is_path_valid, when the path is
+ * valid only if it hasn't been released to systemd already.
+ * PATH_IS_MAYBE_VALID is returned when the the path would be valid
+ * if other paths with the same wwid existed. It is up to the caller
+ * to check for these other paths.
+ */
+enum is_path_valid_result {
+       PATH_IS_ERROR = -1,
+       PATH_IS_NOT_VALID,
+       PATH_IS_VALID,
+       PATH_IS_VALID_NO_CHECK,
+       PATH_IS_MAYBE_VALID,
+       PATH_MAX_VALID_RESULT, /* only for bounds checking */
+};
+
+int is_path_valid(const char *name, struct config *conf, struct path *pp,
+                 bool check_multipathd);
+
+#endif /* _VALID_D */
diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
index 28a2150d..637cb0ab 100644
--- a/libmultipath/wwids.c
+++ b/libmultipath/wwids.c
@@ -289,19 +289,19 @@ out:
 int
 should_multipath(struct path *pp1, vector pathvec, vector mpvec)
 {
-       int i, ignore_new_devs, find_multipaths;
+       int i, find_multipaths;
        struct path *pp2;
        struct config *conf;
 
        conf = get_multipath_config();
-       ignore_new_devs = ignore_new_devs_on(conf);
-       find_multipaths = find_multipaths_on(conf);
+       find_multipaths = conf->find_multipaths;
        put_multipath_config(conf);
-       if (!find_multipaths && !ignore_new_devs)
+       if (find_multipaths == FIND_MULTIPATHS_OFF ||
+           find_multipaths == FIND_MULTIPATHS_GREEDY)
                return 1;
 
        condlog(4, "checking if %s should be multipathed", pp1->dev);
-       if (!ignore_new_devs) {
+       if (find_multipaths != FIND_MULTIPATHS_STRICT) {
                char tmp_wwid[WWID_SIZE];
                struct multipath *mp = find_mp_by_wwid(mpvec, pp1->wwid);
 
diff --git a/multipath/main.c b/multipath/main.c
index 545ead87..953fab27 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -63,21 +63,18 @@
 #include "propsel.h"
 #include "time-util.h"
 #include "file.h"
+#include "valid.h"
 
 int logsink;
 struct udev *udev;
 struct config *multipath_conf;
 
 /*
- * Return values of configure(), print_cmd_valid(), and main().
- * RTVL_{YES,NO} are synonyms for RTVL_{OK,FAIL} for the CMD_VALID_PATH case.
+ * Return values of configure(), check_path_valid(), and main().
  */
 enum {
        RTVL_OK = 0,
-       RTVL_YES = RTVL_OK,
        RTVL_FAIL = 1,
-       RTVL_NO = RTVL_FAIL,
-       RTVL_MAYBE, /* only used internally, never returned */
        RTVL_RETRY, /* returned by configure(), not by main() */
 };
 
@@ -269,9 +266,6 @@ get_dm_mpvec (enum mpath_cmds cmd, vector curmp, vector 
pathvec, char * refwwid)
                        continue;
                }
 
-               if (cmd == CMD_VALID_PATH)
-                       continue;
-
                dm_get_map(mpp->alias, &mpp->size, params);
                condlog(3, "params = %s", params);
                dm_get_status(mpp->alias, status);
@@ -491,10 +485,11 @@ static int print_cmd_valid(int k, const vector pathvec,
        struct timespec until;
        struct path *pp;
 
-       if (k != RTVL_YES && k != RTVL_NO && k != RTVL_MAYBE)
-               return RTVL_NO;
+       if (k != PATH_IS_VALID && k != PATH_IS_NOT_VALID &&
+           k != PATH_IS_MAYBE_VALID)
+               return PATH_IS_NOT_VALID;
 
-       if (k == RTVL_MAYBE) {
+       if (k == PATH_IS_MAYBE_VALID) {
                /*
                 * Caller ensures that pathvec[0] is the path to
                 * examine.
@@ -504,7 +499,7 @@ static int print_cmd_valid(int k, const vector pathvec,
                wait = find_multipaths_check_timeout(
                        pp, pp->find_multipaths_timeout, &until);
                if (wait != FIND_MULTIPATHS_WAITING)
-                       k = RTVL_NO;
+                       k = PATH_IS_NOT_VALID;
        } else if (pathvec != NULL && (pp = VECTOR_SLOT(pathvec, 0)))
                wait = find_multipaths_check_timeout(pp, 0, &until);
        if (wait == FIND_MULTIPATHS_WAITING)
@@ -513,9 +508,9 @@ static int print_cmd_valid(int k, const vector pathvec,
        else if (wait == FIND_MULTIPATHS_WAIT_DONE)
                printf("FIND_MULTIPATHS_WAIT_UNTIL=\"0\"\n");
        printf("DM_MULTIPATH_DEVICE_PATH=\"%d\"\n",
-              k == RTVL_MAYBE ? 2 : k == RTVL_YES ? 1 : 0);
+              k == PATH_IS_MAYBE_VALID ? 2 : k == PATH_IS_VALID ? 1 : 0);
        /* Never return RTVL_MAYBE */
-       return k == RTVL_NO ? RTVL_NO : RTVL_YES;
+       return k == PATH_IS_NOT_VALID ? PATH_IS_NOT_VALID : PATH_IS_VALID;
 }
 
 /*
@@ -548,7 +543,6 @@ configure (struct config *conf, enum mpath_cmds cmd,
        int di_flag = 0;
        char * refwwid = NULL;
        char * dev = NULL;
-       bool released = released_to_systemd();
 
        /*
         * allocate core vectors to store paths and multipaths
@@ -573,7 +567,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
            cmd != CMD_REMOVE_WWID &&
            (filter_devnode(conf->blist_devnode,
                            conf->elist_devnode, dev) > 0)) {
-               goto print_valid;
+               goto out;
        }
 
        /*
@@ -581,14 +575,10 @@ configure (struct config *conf, enum mpath_cmds cmd,
         * failing the translation is fatal (by policy)
         */
        if (devpath) {
-               int failed = get_refwwid(cmd, devpath, dev_type,
-                                        pathvec, &refwwid);
+               get_refwwid(cmd, devpath, dev_type, pathvec, &refwwid);
                if (!refwwid) {
                        condlog(4, "%s: failed to get wwid", devpath);
-                       if (failed == 2 && cmd == CMD_VALID_PATH)
-                               goto print_valid;
-                       else
-                               condlog(3, "scope is null");
+                       condlog(3, "scope is null");
                        goto out;
                }
                if (cmd == CMD_REMOVE_WWID) {
@@ -614,53 +604,6 @@ configure (struct config *conf, enum mpath_cmds cmd,
                        goto out;
                }
                condlog(3, "scope limited to %s", refwwid);
-               /* If you are ignoring the wwids file and find_multipaths is
-                * set, you need to actually check if there are two available
-                * paths to determine if this path should be multipathed. To
-                * do this, we put off the check until after discovering all
-                * the paths.
-                * Paths listed in the wwids file are always considered valid.
-                */
-               if (cmd == CMD_VALID_PATH) {
-                       if (is_failed_wwid(refwwid) == WWID_IS_FAILED) {
-                               r = RTVL_NO;
-                               goto print_valid;
-                       }
-                       if ((!find_multipaths_on(conf) &&
-                                   ignore_wwids_on(conf)) ||
-                                  check_wwids_file(refwwid, 0) == 0)
-                               r = RTVL_YES;
-                       if (!ignore_wwids_on(conf))
-                               goto print_valid;
-                       /* At this point, either r==0 or find_multipaths_on. */
-
-                       /*
-                        * Shortcut for find_multipaths smart:
-                        * Quick check if path is already multipathed.
-                        */
-                       if (sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0),
-                                                false)) {
-                               r = RTVL_YES;
-                               goto print_valid;
-                       }
-
-                       /*
-                        * DM_MULTIPATH_DEVICE_PATH=="0" means that we have
-                        * been called for this device already, and have
-                        * released it to systemd. Unless the device is now
-                        * already multipathed (see above), we can't try to
-                        * grab it, because setting SYSTEMD_READY=0 would
-                        * cause file systems to be unmounted.
-                        * Leave DM_MULTIPATH_DEVICE_PATH="0".
-                        */
-                       if (released) {
-                               r = RTVL_NO;
-                               goto print_valid;
-                       }
-                       if (r == RTVL_YES)
-                               goto print_valid;
-                       /* find_multipaths_on: Fall through to path detection */
-               }
        }
 
        /*
@@ -701,59 +644,6 @@ configure (struct config *conf, enum mpath_cmds cmd,
                goto out;
        }
 
-       if (cmd == CMD_VALID_PATH) {
-               struct path *pp;
-               int fd;
-
-               /* This only happens if find_multipaths and
-                * ignore_wwids is set, and the path is not in WWIDs
-                * file, not currently multipathed, and has
-                * never been released to systemd.
-                * If there is currently a multipath device matching
-                * the refwwid, or there is more than one path matching
-                * the refwwid, then the path is valid */
-               if (VECTOR_SIZE(curmp) != 0) {
-                       r = RTVL_YES;
-                       goto print_valid;
-               } else if (VECTOR_SIZE(pathvec) > 1)
-                       r = RTVL_YES;
-               else
-                       r = RTVL_MAYBE;
-
-               /*
-                * If opening the path with O_EXCL fails, the path
-                * is in use (e.g. mounted during initramfs processing).
-                * We know that it's not used by dm-multipath.
-                * We may not set SYSTEMD_READY=0 on such devices, it
-                * might cause systemd to umount the device.
-                * Use O_RDONLY, because udevd would trigger another
-                * uevent for close-after-write.
-                *
-                * The O_EXCL check is potentially dangerous, because it may
-                * race with other tasks trying to access the device. Therefore
-                * this code is only executed if the path hasn't been released
-                * to systemd earlier (see above).
-                *
-                * get_refwwid() above stores the path we examine in slot 0.
-                */
-               pp = VECTOR_SLOT(pathvec, 0);
-               fd = open(udev_device_get_devnode(pp->udev),
-                         O_RDONLY|O_EXCL);
-               if (fd >= 0)
-                       close(fd);
-               else {
-                       condlog(3, "%s: path %s is in use: %s",
-                               __func__, pp->dev,
-                               strerror(errno));
-                       /*
-                        * Check if we raced with multipathd
-                        */
-                       r = sysfs_is_multipathed(VECTOR_SLOT(pathvec, 0),
-                                                false) ? RTVL_YES : RTVL_NO;
-               }
-               goto print_valid;
-       }
-
        if (cmd != CMD_CREATE && cmd != CMD_DRY_RUN) {
                r = RTVL_OK;
                goto out;
@@ -766,10 +656,6 @@ configure (struct config *conf, enum mpath_cmds cmd,
                           conf->force_reload, cmd);
        r = rc == CP_RETRY ? RTVL_RETRY : rc == CP_OK ? RTVL_OK : RTVL_FAIL;
 
-print_valid:
-       if (cmd == CMD_VALID_PATH)
-               r = print_cmd_valid(r, pathvec, conf);
-
 out:
        if (refwwid)
                FREE(refwwid);
@@ -780,6 +666,112 @@ out:
        return r;
 }
 
+static int
+check_path_valid(const char *name, struct config *conf, bool is_uevent)
+{
+       int fd, r = PATH_IS_ERROR;
+       struct path *pp = NULL;
+       vector pathvec = NULL;
+
+       pp = alloc_path();
+       if (!pp)
+               return RTVL_FAIL;
+
+       r = is_path_valid(name, conf, pp, is_uevent);
+       if (r <= PATH_IS_ERROR || r >= PATH_MAX_VALID_RESULT)
+               goto fail;
+
+       /* set path values if is_path_valid() didn't */
+       if (!pp->udev)
+               pp->udev = udev_device_new_from_subsystem_sysname(udev, "block",
+                                                                 name);
+       if (!pp->udev)
+               goto fail;
+
+       if (!strlen(pp->dev_t)) {
+               dev_t devt = udev_device_get_devnum(pp->udev);
+               if (major(devt) == 0 && minor(devt) == 0)
+                       goto fail;
+               snprintf(pp->dev_t, BLK_DEV_SIZE, "%d:%d", major(devt),
+                        minor(devt));
+       }
+
+       pathvec = vector_alloc();
+       if (!pathvec)
+               goto fail;
+
+       if (store_path(pathvec, pp) != 0) {
+               free_path(pp);
+               goto fail;
+       }
+
+       if ((r == PATH_IS_VALID || r == PATH_IS_MAYBE_VALID) &&
+           released_to_systemd())
+               r = PATH_IS_NOT_VALID;
+
+       /* This state is only used to skip the released_to_systemd() check */
+       if (r == PATH_IS_VALID_NO_CHECK)
+               r = PATH_IS_VALID;
+
+       if (r != PATH_IS_MAYBE_VALID)
+               goto out;
+
+       /*
+        * If opening the path with O_EXCL fails, the path
+        * is in use (e.g. mounted during initramfs processing).
+        * We know that it's not used by dm-multipath.
+        * We may not set SYSTEMD_READY=0 on such devices, it
+        * might cause systemd to umount the device.
+        * Use O_RDONLY, because udevd would trigger another
+        * uevent for close-after-write.
+        *
+        * The O_EXCL check is potentially dangerous, because it may
+        * race with other tasks trying to access the device. Therefore
+        * this code is only executed if the path hasn't been released
+        * to systemd earlier (see above).
+        */
+       fd = open(udev_device_get_devnode(pp->udev), O_RDONLY|O_EXCL);
+       if (fd >= 0)
+               close(fd);
+       else {
+               condlog(3, "%s: path %s is in use: %m", __func__, pp->dev);
+               /* Check if we raced with multipathd */
+               if (sysfs_is_multipathed(pp, false))
+                       r = PATH_IS_VALID;
+               else
+                       r = PATH_IS_NOT_VALID;
+               goto out;
+       }
+
+       /* For find_multipaths = SMART, if there is more than one path
+        * matching the refwwid, then the path is valid */
+       if (path_discovery(pathvec, DI_SYSFS | DI_WWID) < 0)
+               goto fail;
+       filter_pathvec(pathvec, pp->wwid);
+       if (VECTOR_SIZE(pathvec) > 1)
+               r = PATH_IS_VALID;
+       else
+               r = PATH_IS_MAYBE_VALID;
+
+out:
+       r = print_cmd_valid(r, pathvec, conf);
+       free_pathvec(pathvec, FREE_PATHS);
+       /*
+        * multipath -u must exit with status 0, otherwise udev won't
+        * import its output.
+        */
+       if (!is_uevent && r == PATH_IS_NOT_VALID)
+               return RTVL_FAIL;
+       return RTVL_OK;
+
+fail:
+       if (pathvec)
+               free_pathvec(pathvec, FREE_PATHS);
+       else
+               free_path(pp);
+       return RTVL_FAIL;
+}
+
 static int
 get_dev_type(char *dev) {
        struct stat buf;
@@ -861,32 +853,6 @@ out:
        return r;
 }
 
-static int test_multipathd_socket(void)
-{
-       int fd;
-       /*
-        * "multipath -u" may be run before the daemon is started. In this
-        * case, systemd might own the socket but might delay multipathd
-        * startup until some other unit (udev settle!)  has finished
-        * starting. With many LUNs, the listen backlog may be exceeded, which
-        * would cause connect() to block. This causes udev workers calling
-        * "multipath -u" to hang, and thus creates a deadlock, until "udev
-        * settle" times out.  To avoid this, call connect() in non-blocking
-        * mode here, and take EAGAIN as indication for a filled-up systemd
-        * backlog.
-        */
-
-       fd = __mpath_connect(1);
-       if (fd == -1) {
-               if (errno == EAGAIN)
-                       condlog(3, "daemon backlog exceeded");
-               else
-                       return 0;
-       } else
-               close(fd);
-       return 1;
-}
-
 int
 main (int argc, char *argv[])
 {
@@ -970,7 +936,11 @@ main (int argc, char *argv[])
                        conf->force_reload = FORCE_RELOAD_YES;
                        break;
                case 'i':
-                       conf->find_multipaths |= _FIND_MULTIPATHS_I;
+                       if (conf->find_multipaths == FIND_MULTIPATHS_ON ||
+                           conf->find_multipaths == FIND_MULTIPATHS_STRICT)
+                               conf->find_multipaths = FIND_MULTIPATHS_SMART;
+                       else if (conf->find_multipaths == FIND_MULTIPATHS_OFF)
+                               conf->find_multipaths = FIND_MULTIPATHS_GREEDY;
                        break;
                case 't':
                        r = dump_config(conf, NULL, NULL) ? RTVL_FAIL : RTVL_OK;
@@ -1064,15 +1034,10 @@ main (int argc, char *argv[])
                condlog(0, "the -c option requires a path to check");
                goto out;
        }
-       if (cmd == CMD_VALID_PATH &&
-           dev_type == DEV_UEVENT) {
-               if (!test_multipathd_socket()) {
-                       condlog(3, "%s: daemon is not running", dev);
-                       if (!systemd_service_enabled(dev)) {
-                               r = print_cmd_valid(RTVL_NO, NULL, conf);
-                               goto out;
-                       }
-               }
+       if (cmd == CMD_VALID_PATH) {
+               char * name = convert_dev(dev, (dev_type == DEV_DEVNODE));
+               r = check_path_valid(name, conf, dev_type == DEV_UEVENT);
+               goto out;
        }
 
        if (cmd == CMD_REMOVE_WWID && !dev) {
@@ -1136,13 +1101,6 @@ out:
        cleanup_prio();
        cleanup_checkers();
 
-       /*
-        * multipath -u must exit with status 0, otherwise udev won't
-        * import its output.
-        */
-       if (cmd == CMD_VALID_PATH && dev_type == DEV_UEVENT && r == RTVL_NO)
-               r = RTVL_OK;
-
        if (dev_type == DEV_UEVENT)
                closelog();
 
-- 
2.17.2

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