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Merge pull request #23088 from yuwata/udev-event-blocker

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udev: cleanups for event blocker
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2022-07-02 17:08:45 +02:00 committed by GitHub
commit 025f1279c7
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4 changed files with 59 additions and 76 deletions
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13
src/shared/udev-util.c
View File

@ -568,6 +568,19 @@ int udev_resolve_subsys_kernel(const char *string, char *result, size_t maxsize,
return 0;
}
bool devpath_conflict(const char *a, const char *b) {
/* This returns true when two paths are equivalent, or one is a child of another. */
if (!a || !b)
return false;
for (; *a != '\0' && *b != '\0'; a++, b++)
if (*a != *b)
return false;
return *a == '/' || *b == '/' || *a == *b;
}
int udev_queue_is_empty(void) {
return access("/run/udev/queue", F_OK) < 0 ?
(errno == ENOENT ? true : -errno) : false;

2
src/shared/udev-util.h
View File

@ -50,6 +50,8 @@ size_t udev_replace_ifname(char *str);
size_t udev_replace_chars(char *str, const char *allow);
int udev_resolve_subsys_kernel(const char *string, char *result, size_t maxsize, bool read_value);
bool devpath_conflict(const char *a, const char *b);
int udev_queue_is_empty(void);
int udev_queue_init(void);

13
src/test/test-udev-util.c
View File

@ -155,4 +155,17 @@ TEST(udev_resolve_subsys_kernel) {
test_udev_resolve_subsys_kernel_one("[net/lo]/address", true, 0, "00:00:00:00:00:00");
}
TEST(devpath_conflict) {
assert_se(!devpath_conflict(NULL, NULL));
assert_se(!devpath_conflict(NULL, "/devices/pci0000:00/0000:00:1c.4"));
assert_se(!devpath_conflict("/devices/pci0000:00/0000:00:1c.4", NULL));
assert_se(!devpath_conflict("/devices/pci0000:00/0000:00:1c.4", "/devices/pci0000:00/0000:00:00.0"));
assert_se(!devpath_conflict("/devices/virtual/net/veth99", "/devices/virtual/net/veth999"));
assert_se(devpath_conflict("/devices/pci0000:00/0000:00:1c.4", "/devices/pci0000:00/0000:00:1c.4"));
assert_se(devpath_conflict("/devices/pci0000:00/0000:00:1c.4", "/devices/pci0000:00/0000:00:1c.4/0000:3c:00.0"));
assert_se(devpath_conflict("/devices/pci0000:00/0000:00:1c.4/0000:3c:00.0/nvme/nvme0/nvme0n1",
"/devices/pci0000:00/0000:00:1c.4/0000:3c:00.0/nvme/nvme0/nvme0n1/nvme0n1p1"));
}
DEFINE_TEST_MAIN(LOG_INFO);

107
src/udev/udevd.c
View File

@ -131,6 +131,10 @@ typedef struct Event {
sd_device_action_t action;
uint64_t seqnum;
uint64_t blocker_seqnum;
const char *id;
const char *devpath;
const char *devpath_old;
const char *devnode;
usec_t retry_again_next_usec;
usec_t retry_again_timeout_usec;
@ -852,12 +856,8 @@ static int event_run(Event *event) {
}
static int event_is_blocked(Event *event) {
const char *subsystem, *devpath, *devpath_old = NULL;
dev_t devnum = makedev(0, 0);
Event *loop_event = NULL;
size_t devpath_len;
int r, ifindex = 0;
bool is_block;
int r;
/* lookup event for identical, parent, child device */
@ -903,89 +903,23 @@ static int event_is_blocked(Event *event) {
assert(loop_event->seqnum > event->blocker_seqnum &&
loop_event->seqnum < event->seqnum);
r = sd_device_get_subsystem(event->dev, &subsystem);
if (r < 0)
return r;
is_block = streq(subsystem, "block");
r = sd_device_get_devpath(event->dev, &devpath);
if (r < 0)
return r;
devpath_len = strlen(devpath);
r = sd_device_get_property_value(event->dev, "DEVPATH_OLD", &devpath_old);
if (r < 0 && r != -ENOENT)
return r;
r = sd_device_get_devnum(event->dev, &devnum);
if (r < 0 && r != -ENOENT)
return r;
r = sd_device_get_ifindex(event->dev, &ifindex);
if (r < 0 && r != -ENOENT)
return r;
/* check if queue contains events we depend on */
LIST_FOREACH(event, e, loop_event) {
size_t loop_devpath_len, common;
const char *loop_devpath;
loop_event = e;
/* found ourself, no later event can block us */
if (loop_event->seqnum >= event->seqnum)
goto no_blocker;
/* check major/minor */
if (major(devnum) != 0) {
const char *s;
dev_t d;
if (sd_device_get_subsystem(loop_event->dev, &s) < 0)
continue;
if (sd_device_get_devnum(loop_event->dev, &d) >= 0 &&
devnum == d && is_block == streq(s, "block"))
break;
}
/* check network device ifindex */
if (ifindex > 0) {
int i;
if (sd_device_get_ifindex(loop_event->dev, &i) >= 0 &&
ifindex == i)
break;
}
if (sd_device_get_devpath(loop_event->dev, &loop_devpath) < 0)
continue;
/* check our old name */
if (devpath_old && streq(devpath_old, loop_devpath))
if (streq_ptr(loop_event->id, event->id))
break;
loop_devpath_len = strlen(loop_devpath);
/* compare devpath */
common = MIN(devpath_len, loop_devpath_len);
/* one devpath is contained in the other? */
if (!strneq(devpath, loop_devpath, common))
continue;
/* identical device event found */
if (devpath_len == loop_devpath_len)
if (devpath_conflict(event->devpath, loop_event->devpath) ||
devpath_conflict(event->devpath, loop_event->devpath_old) ||
devpath_conflict(event->devpath_old, loop_event->devpath))
break;
/* parent device event found */
if (devpath[common] == '/')
break;
/* child device event found */
if (loop_devpath[common] == '/')
if (event->devnode && streq_ptr(event->devnode, loop_event->devnode))
break;
}
@ -1134,6 +1068,7 @@ static int event_queue_assume_block_device_unlocked(Manager *manager, sd_device
}
static int event_queue_insert(Manager *manager, sd_device *dev) {
const char *devpath, *devpath_old = NULL, *id = NULL, *devnode = NULL;
sd_device_action_t action;
uint64_t seqnum;
Event *event;
@ -1154,6 +1089,22 @@ static int event_queue_insert(Manager *manager, sd_device *dev) {
if (r < 0)
return r;
r = sd_device_get_devpath(dev, &devpath);
if (r < 0)
return r;
r = sd_device_get_property_value(dev, "DEVPATH_OLD", &devpath_old);
if (r < 0 && r != -ENOENT)
return r;
r = device_get_device_id(dev, &id);
if (r < 0 && r != -ENOENT)
return r;
r = sd_device_get_devname(dev, &devnode);
if (r < 0 && r != -ENOENT)
return r;
event = new(Event, 1);
if (!event)
return -ENOMEM;
@ -1163,6 +1114,10 @@ static int event_queue_insert(Manager *manager, sd_device *dev) {
.dev = sd_device_ref(dev),
.seqnum = seqnum,
.action = action,
.id = id,
.devpath = devpath,
.devpath_old = devpath_old,
.devnode = devnode,
.state = EVENT_QUEUED,
};