From 6b8fedd82c23f1d8c334c3081a1befebedc40f1f Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Tue, 19 May 2015 13:50:36 +0200

Subject: [PATCH] mount: don't claim a device is gone from /proc/self/mountinfo

 before it is gone from *all* lines

Devices might be referenced by multiple mount points in

/proc/self/mountinfo, hence we should consider them unmounted only after

they disappeared from all lines, not just from one.

http://lists.freedesktop.org/archives/systemd-devel/2015-May/032026.html

(cherry picked from commit fcd8b266edf0df2b85079fcf7b099cd4028740e6)

Cherry-picked from:

Resolves: #1222517

---

 src/core/mount.c | 30 +++++++++++++++++++++++++++---

 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/core/mount.c b/src/core/mount.c

index fd4fb6f1b2..fa63f2426f 100644

--- a/src/core/mount.c

+++ b/src/core/mount.c

@@ -1698,7 +1698,10 @@ fail:

 }

 static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {

+        _cleanup_set_free_ Set *around = NULL, *gone = NULL;

         Manager *m = userdata;

+        const char *what;

+        Iterator i;

         Unit *u;

         int r;

@@ -1765,6 +1768,8 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents,

                 if (!mount->is_mounted) {

+                        /* A mount point is gone */

+

                         mount->from_proc_self_mountinfo = false;

                         switch (mount->state) {

@@ -1780,13 +1785,17 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents,

                                 break;

                         }

-                        if (mount->parameters_proc_self_mountinfo.what)

-                                (void) device_found_node(m, mount->parameters_proc_self_mountinfo.what, false, DEVICE_FOUND_MOUNT, true);

+                        /* Remember that this device might just have disappeared */

+                        if (mount->parameters_proc_self_mountinfo.what) {

+                                if (set_ensure_allocated(&gone, &string_hash_ops) < 0 ||

+                                    set_put(gone, mount->parameters_proc_self_mountinfo.what) < 0)

+                                        log_oom(); /* we don't care too much about OOM here... */

+                        }

                 } else if (mount->just_mounted || mount->just_changed) {

-                        /* New or changed mount entry */

+                        /* A mount point was added or changed */

                         switch (mount->state) {

@@ -1811,12 +1820,27 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents,

                                 mount_set_state(mount, mount->state);

                                 break;

                         }

+

+                        if (mount->parameters_proc_self_mountinfo.what) {

+

+                                if (set_ensure_allocated(&around, &string_hash_ops) < 0 ||

+                                    set_put(around, mount->parameters_proc_self_mountinfo.what) < 0)

+                                        log_oom();

+                        }

                 }

                 /* Reset the flags for later calls */

                 mount->is_mounted = mount->just_mounted = mount->just_changed = false;

         }

+        SET_FOREACH(what, gone, i) {

+                if (set_contains(around, what))

+                        continue;

+

+                /* Let the device units know that the device is no longer mounted */

+                (void) device_found_node(m, what, false, DEVICE_FOUND_MOUNT, true);

+        }

+

         return 0;

 }