From 6b8fedd82c23f1d8c334c3081a1befebedc40f1f Mon Sep 17 00:00:00 2001 From: Lennart Poettering 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; }