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udevd: implement a more efficient queue file format

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Directory lookups show up in profiling. The queue files are responsible
for a large proportion of file-related system calls in udev coldplug.

Instead of creating a file for each event, append their details to a
log file.  The file is periodically rebuilt (garbage-collected) to
prevent it from growing indefinitely.

This single queue file replaces both the queue directory and the
uevent_seqnum file. On desktop systems the file tends not to grow
beyond one page. So it should also save a small amount of memory in
tmpfs.

Tests on a running EeePC indicate average savings of 5% *udevd* cpu time
as measured by oprofile. __link_path_walk is reduced from 1.5% to
1.3%. It is not completely clear where the rest of the gains come from.

In tests running ~400 events, the queue file is rebuilt about 5 times.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
This commit is contained in:
Alan Jenkins 2009-05-21 22:22:37 +02:00 committed by Kay Sievers
parent f9b3f88f71
commit f503f6b22f
9 changed files with 728 additions and 259 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
configure.ac
View File

@ -14,9 +14,9 @@ AC_PREFIX_DEFAULT([/usr])
test "$prefix" = NONE && test "$exec_prefix" = NONE && exec_prefix=
dnl /* libudev version */
LIBUDEV_LT_CURRENT=3
LIBUDEV_LT_CURRENT=4
LIBUDEV_LT_REVISION=0
LIBUDEV_LT_AGE=3
LIBUDEV_LT_AGE=4
AC_SUBST(LIBUDEV_LT_CURRENT)
AC_SUBST(LIBUDEV_LT_REVISION)
AC_SUBST(LIBUDEV_LT_AGE)

1
udev/Makefile.am
View File

@ -30,6 +30,7 @@ common_files = \
lib/libudev-monitor.c \
lib/libudev-enumerate.c \
lib/libudev-queue.c \
lib/libudev-queue-export.c \
lib/libudev-ctrl.c
if USE_SELINUX

1
udev/lib/exported_symbols
View File

@ -68,5 +68,6 @@ udev_queue_get_udev_seqnum
udev_queue_get_udev_is_active
udev_queue_get_queue_is_empty
udev_queue_get_seqnum_is_finished
udev_queue_get_seqnum_sequence_is_finished
udev_queue_get_queued_list_entry
udev_queue_get_failed_list_entry

16
udev/lib/libudev-private.h
View File

@ -150,10 +150,18 @@ void udev_list_entry_set_flag(struct udev_list_entry *list_entry, int flag);
entry = tmp, tmp = udev_list_entry_get_next(tmp))
/* libudev-queue */
int udev_queue_export_udev_seqnum(struct udev_queue *udev_queue, unsigned long long int seqnum);
int udev_queue_export_device_queued(struct udev_queue *udev_queue, struct udev_device *udev_device);
int udev_queue_export_device_finished(struct udev_queue *udev_queue, struct udev_device *udev_device);
int udev_queue_export_device_failed(struct udev_queue *udev_queue, struct udev_device *udev_device);
unsigned long long int udev_get_kernel_seqnum(struct udev *udev);
int udev_queue_read_seqnum(FILE *queue_file, unsigned long long int *seqnum);
ssize_t udev_queue_read_devpath(FILE *queue_file, char *devpath, size_t size);
ssize_t udev_queue_skip_devpath(FILE *queue_file);
/* libudev-queue-export */
struct udev_queue_export *udev_queue_export_new(struct udev *udev);
void udev_queue_export_unref(struct udev_queue_export *udev_queue_export);
void udev_queue_export_cleanup(struct udev_queue_export *udev_queue_export);
int udev_queue_export_device_queued(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device);
int udev_queue_export_device_finished(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device);
int udev_queue_export_device_failed(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device);
/* libudev-utils */
#define UTIL_PATH_SIZE 1024

473
udev/lib/libudev-queue-export.c Normal file
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@ -0,0 +1,473 @@
/*
* libudev - interface to udev device information
*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*/
/*
* DISCLAIMER - The file format mentioned here is private to udev/libudev,
* and may be changed without notice.
*
*
* The udev event queue is exported as a binary log file.
* Each log record consists of a sequence number followed by the device path.
*
* When a new event is queued, its details are appended to the log.
* When the event finishes, a second record is appended to the log
* with the same sequence number but a null devpath.
*
* Example:
* {1, "/devices/virtual/mem/null" },
* {2, "/devices/virtual/mem/zero" },
* {1, "" },
* Event 2 is still queued, but event 1 has been finished
*
* The queue does not grow indefinitely. It is periodically re-created
* to remove finished events. Atomic rename() makes this transparent to readers.
*
*
* The queue file starts with a single sequence number which specifies the
* minimum sequence number in the log that follows. Any events prior to this
* sequence number have already finished.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <assert.h>
#include "udev.h"
static int rebuild_queue_file(struct udev_queue_export *udev_queue_export);
struct udev_queue_export {
struct udev *udev;
int failed_count; /* number of failed events exported */
int queued_count; /* number of unfinished events exported in queue file */
FILE *queue_file;
unsigned long long int seqnum_max; /* earliest sequence number in queue file */
unsigned long long int seqnum_min; /* latest sequence number in queue file */
int waste_bytes; /* queue file bytes wasted on finished events */
};
struct udev_queue_export *udev_queue_export_new(struct udev *udev)
{
struct udev_queue_export *udev_queue_export;
unsigned long long int initial_seqnum;
if (udev == NULL)
return NULL;
udev_queue_export = calloc(1, sizeof(struct udev_queue_export));
if (udev_queue_export == NULL)
return NULL;
udev_queue_export->udev = udev;
initial_seqnum = udev_get_kernel_seqnum(udev);
udev_queue_export->seqnum_min = initial_seqnum;
udev_queue_export->seqnum_max = initial_seqnum;
udev_queue_export_cleanup(udev_queue_export);
if (rebuild_queue_file(udev_queue_export) != 0) {
free(udev_queue_export);
return NULL;
}
return udev_queue_export;
}
void udev_queue_export_unref(struct udev_queue_export *udev_queue_export)
{
if (udev_queue_export == NULL)
return;
if (udev_queue_export->queue_file != NULL)
fclose(udev_queue_export->queue_file);
free(udev_queue_export);
}
void udev_queue_export_cleanup(struct udev_queue_export *udev_queue_export)
{
char filename[UTIL_PATH_SIZE];
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue_export->udev), "/.udev/queue.tmp", NULL);
unlink(filename);
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue_export->udev), "/.udev/queue.bin", NULL);
unlink(filename);
}
static int skip_to(FILE *file, long offset)
{
long old_offset;
/* fseek may drop buffered data, avoid it for small seeks */
old_offset = ftell(file);
if (offset > old_offset && old_offset - offset <= BUFSIZ) {
size_t skip_bytes = old_offset - offset;
char buf[skip_bytes];
if (fread(buf, skip_bytes, 1, file) != skip_bytes)
return -1;
}
return fseek(file, offset, SEEK_SET);
}
struct queue_devpaths {
unsigned int devpaths_first; /* index of first queued event */
unsigned int devpaths_size;
long devpaths[]; /* seqnum -> offset of devpath in queue file (or 0) */
};
/*
* Returns a table mapping seqnum to devpath file offset for currently queued events.
* devpaths[i] represents the event with seqnum = i + udev_queue_export->seqnum_min.
*/
static struct queue_devpaths *build_index(struct udev_queue_export *udev_queue_export)
{
struct queue_devpaths *devpaths;
unsigned long long int range;
long devpath_offset;
ssize_t devpath_len;
unsigned long long int seqnum;
unsigned long long int n;
unsigned int i;
/* seek to the first event in the file */
rewind(udev_queue_export->queue_file);
udev_queue_read_seqnum(udev_queue_export->queue_file, &seqnum);
/* allocate the table */
range = udev_queue_export->seqnum_min - udev_queue_export->seqnum_max;
if (range - 1 > INT_MAX) {
err(udev_queue_export->udev, "queue file overflow\n");
return NULL;
}
devpaths = calloc(1, sizeof(struct queue_devpaths) + (range + 1) * sizeof(long));
if (index == NULL)
return NULL;
devpaths->devpaths_size = range + 1;
/* read all records and populate the table */
while(1) {
if (udev_queue_read_seqnum(udev_queue_export->queue_file, &seqnum) < 0)
break;
n = seqnum - udev_queue_export->seqnum_max;
if (n >= devpaths->devpaths_size)
goto read_error;
devpath_offset = ftell(udev_queue_export->queue_file);
devpath_len = udev_queue_skip_devpath(udev_queue_export->queue_file);
if (devpath_len < 0)
goto read_error;
if (devpath_len > 0)
devpaths->devpaths[n] = devpath_offset;
else
devpaths->devpaths[n] = 0;
}
/* find first queued event */
for (i = 0; i < devpaths->devpaths_size; i++) {
if (devpaths->devpaths[i] != 0)
break;
}
devpaths->devpaths_first = i;
return devpaths;
read_error:
err(udev_queue_export->udev, "queue file corrupted\n");
free(devpaths);
return NULL;
}
static int rebuild_queue_file(struct udev_queue_export *udev_queue_export)
{
unsigned long long int seqnum;
struct queue_devpaths *devpaths = NULL;
char filename[UTIL_PATH_SIZE];
char filename_tmp[UTIL_PATH_SIZE];
FILE *new_queue_file = NULL;
unsigned int i;
/* read old queue file */
if (udev_queue_export->queue_file != NULL) {
dbg(udev_queue_export->udev, "compacting queue file, freeing %d bytes\n",
udev_queue_export->waste_bytes);
devpaths = build_index(udev_queue_export);
if (devpaths != NULL)
udev_queue_export->seqnum_max += devpaths->devpaths_first;
}
if (devpaths == NULL) {
dbg(udev_queue_export->udev, "creating empty queue file\n");
udev_queue_export->queued_count = 0;
udev_queue_export->seqnum_max = udev_queue_export->seqnum_min;
}
/* create new queue file */
util_strscpyl(filename_tmp, sizeof(filename_tmp), udev_get_dev_path(udev_queue_export->udev), "/.udev/queue.tmp", NULL);
new_queue_file = fopen(filename_tmp, "w+");
if (new_queue_file == NULL)
goto error;
seqnum = udev_queue_export->seqnum_max;
fwrite(&seqnum, 1, sizeof(unsigned long long int), new_queue_file);
/* copy unfinished events only to the new file */
if (devpaths != NULL) {
for (i = devpaths->devpaths_first; i < devpaths->devpaths_size; i++) {
char devpath[UTIL_PATH_SIZE];
int err;
unsigned short devpath_len;
if (devpaths->devpaths[i] != 0)
{
skip_to(udev_queue_export->queue_file, devpaths->devpaths[i]);
err = udev_queue_read_devpath(udev_queue_export->queue_file, devpath, sizeof(devpath));
devpath_len = err;
fwrite(&seqnum, sizeof(unsigned long long int), 1, new_queue_file);
fwrite(&devpath_len, sizeof(unsigned short), 1, new_queue_file);
fwrite(devpath, 1, devpath_len, new_queue_file);
}
seqnum++;
}
free(devpaths);
devpaths = NULL;
}
fflush(new_queue_file);
if (ferror(new_queue_file))
goto error;
/* rename the new file on top of the old one */
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue_export->udev), "/.udev/queue.bin", NULL);
if (rename(filename_tmp, filename) != 0)
goto error;
if (udev_queue_export->queue_file != NULL)
fclose(udev_queue_export->queue_file);
udev_queue_export->queue_file = new_queue_file;
udev_queue_export->waste_bytes = 0;
return 0;
error:
err(udev_queue_export->udev, "failed to create queue file: %m\n");
udev_queue_export_cleanup(udev_queue_export);
if (udev_queue_export->queue_file != NULL) {
fclose(udev_queue_export->queue_file);
udev_queue_export->queue_file = NULL;
}
if (new_queue_file != NULL)
fclose(new_queue_file);
if (devpaths != NULL)
free(devpaths);
udev_queue_export->queued_count = 0;
udev_queue_export->waste_bytes = 0;
udev_queue_export->seqnum_max = udev_queue_export->seqnum_min;
return -1;
}
static int write_queue_record(struct udev_queue_export *udev_queue_export,
unsigned long long int seqnum, const char *devpath, size_t devpath_len)
{
unsigned short len;
if (udev_queue_export->queue_file == NULL) {
dbg(udev_queue_export->udev, "can't record event: queue file not available\n");
return -1;
}
if (fwrite(&seqnum, sizeof(unsigned long long int), 1, udev_queue_export->queue_file) != 1)
goto write_error;
len = (devpath_len < USHRT_MAX) ? devpath_len : USHRT_MAX;
if (fwrite(&len, sizeof(unsigned short), 1, udev_queue_export->queue_file) != 1)
goto write_error;
if (fwrite(devpath, 1, len, udev_queue_export->queue_file) != len)
goto write_error;
/* *must* flush output; caller may fork */
if (fflush(udev_queue_export->queue_file) != 0)
goto write_error;
return 0;
write_error:
/* if we failed half way through writing a record to a file,
we should not try to write any further records to it. */
err(udev_queue_export->udev, "error writing to queue file: %m\n");
fclose(udev_queue_export->queue_file);
udev_queue_export->queue_file = NULL;
return -1;
}
enum device_state {
DEVICE_QUEUED,
DEVICE_FINISHED,
DEVICE_FAILED,
};
static inline size_t queue_record_size(size_t devpath_len)
{
return sizeof(unsigned long long int) + sizeof(unsigned short int) + devpath_len;
}
static int update_queue(struct udev_queue_export *udev_queue_export,
struct udev_device *udev_device, enum device_state state)
{
unsigned long long int seqnum = udev_device_get_seqnum(udev_device);
const char *devpath = NULL;
size_t devpath_len = 0;
int bytes;
int err;
if (state == DEVICE_QUEUED) {
devpath = udev_device_get_devpath(udev_device);
devpath_len = strlen(devpath);
}
/* recover from an earlier failed rebuild */
if (udev_queue_export->queue_file == NULL) {
if (rebuild_queue_file(udev_queue_export) != 0)
return -1;
}
/* when the queue files grow too large, they must be garbage collected and rebuilt */
bytes = ftell(udev_queue_export->queue_file) + queue_record_size(devpath_len);
/* if we're removing the last event from the queue, that's the best time to rebuild it */
if (state != DEVICE_QUEUED && udev_queue_export->queued_count == 1 && bytes > 2048) {
/* because we don't need to read the old queue file */
fclose(udev_queue_export->queue_file);
udev_queue_export->queue_file = NULL;
rebuild_queue_file(udev_queue_export);
return 0;
}
/* try to rebuild the queue files before they grow larger than one page. */
if ((udev_queue_export->waste_bytes > bytes / 2) && bytes > 4096)
rebuild_queue_file(udev_queue_export);
/* don't record a finished event, if we already dropped the event in a failed rebuild */
if (seqnum < udev_queue_export->seqnum_max)
return 0;
/* now write to the queue */
if (state == DEVICE_QUEUED) {
udev_queue_export->queued_count++;
udev_queue_export->seqnum_min = seqnum;
} else {
udev_queue_export->waste_bytes += queue_record_size(devpath_len) + queue_record_size(0);
udev_queue_export->queued_count--;
}
err = write_queue_record(udev_queue_export, seqnum, devpath, devpath_len);
/* try to handle ENOSPC */
if (err != 0 && udev_queue_export->queued_count == 0) {
udev_queue_export_cleanup(udev_queue_export);
err = rebuild_queue_file(udev_queue_export);
}
return err;
}
static void update_failed(struct udev_queue_export *udev_queue_export,
struct udev_device *udev_device, enum device_state state)
{
struct udev *udev = udev_device_get_udev(udev_device);
char filename[UTIL_PATH_SIZE];
char *s;
size_t l;
if (state != DEVICE_FAILED && udev_queue_export->failed_count == 0)
return;
/* location of failed file */
s = filename;
l = util_strpcpyl(&s, sizeof(filename), udev_get_dev_path(udev_queue_export->udev), "/.udev/failed/", NULL);
util_path_encode(udev_device_get_devpath(udev_device), s, l);
switch (state) {
case DEVICE_FAILED:
/* record event in the failed directory */
if (udev_queue_export->failed_count == 0)
util_create_path(udev, filename);
udev_queue_export->failed_count++;
udev_selinux_setfscreatecon(udev, filename, S_IFLNK);
symlink(udev_device_get_devpath(udev_device), filename);
udev_selinux_resetfscreatecon(udev);
break;
case DEVICE_QUEUED:
/* delete failed file */
if (unlink(filename) == 0) {
util_delete_path(udev, filename);
udev_queue_export->failed_count--;
}
break;
case DEVICE_FINISHED:
if (udev_device_get_devpath_old(udev_device) != NULL) {
/* "move" event - rename failed file to current name, do not delete failed */
char filename_old[UTIL_PATH_SIZE];
s = filename_old;
l = util_strpcpyl(&s, sizeof(filename_old), udev_get_dev_path(udev_queue_export->udev), "/.udev/failed/", NULL);
util_path_encode(udev_device_get_devpath_old(udev_device), s, l);
if (rename(filename_old, filename) == 0)
info(udev, "renamed devpath, moved failed state of '%s' to %s'\n",
udev_device_get_devpath_old(udev_device), udev_device_get_devpath(udev_device));
}
break;
}
return;
}
static int update(struct udev_queue_export *udev_queue_export,
struct udev_device *udev_device, enum device_state state)
{
update_failed(udev_queue_export, udev_device, state);
if (update_queue(udev_queue_export, udev_device, state) != 0)
return -1;
return 0;
}
int udev_queue_export_device_queued(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device)
{
return update(udev_queue_export, udev_device, DEVICE_QUEUED);
}
int udev_queue_export_device_finished(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device)
{
return update(udev_queue_export, udev_device, DEVICE_FINISHED);
}
int udev_queue_export_device_failed(struct udev_queue_export *udev_queue_export, struct udev_device *udev_device)
{
return update(udev_queue_export, udev_device, DEVICE_FAILED);
}

314
udev/lib/libudev-queue.c
View File

@ -2,6 +2,7 @@
* libudev - interface to udev device information
*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -17,6 +18,7 @@
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/stat.h>
#include "libudev.h"
@ -25,7 +27,6 @@
struct udev_queue {
struct udev *udev;
int refcount;
unsigned long long int last_seen_udev_seqnum;
struct udev_list_node queue_list;
struct udev_list_node failed_list;
};
@ -74,7 +75,7 @@ struct udev *udev_queue_get_udev(struct udev_queue *udev_queue)
return udev_queue->udev;
}
unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
unsigned long long int udev_get_kernel_seqnum(struct udev *udev)
{
char filename[UTIL_PATH_SIZE];
unsigned long long int seqnum;
@ -82,9 +83,7 @@ unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queu
char buf[32];
ssize_t len;
if (udev_queue == NULL)
return -EINVAL;
util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev_queue->udev), "/kernel/uevent_seqnum", NULL);
util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev), "/kernel/uevent_seqnum", NULL);
fd = open(filename, O_RDONLY);
if (fd < 0)
return 0;
@ -94,130 +93,271 @@ unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queu
return 0;
buf[len-1] = '\0';
seqnum = strtoull(buf, NULL, 10);
return seqnum;
}
unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
{
unsigned long long int seqnum;
if (udev_queue == NULL)
return -EINVAL;
seqnum = udev_get_kernel_seqnum(udev_queue->udev);
dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
return seqnum;
}
unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
int udev_queue_read_seqnum(FILE *queue_file, unsigned long long int *seqnum)
{
if (fread(seqnum, sizeof(unsigned long long int), 1, queue_file) != 1)
return -1;
return 0;
}
ssize_t udev_queue_skip_devpath(FILE *queue_file)
{
unsigned short int len;
if (fread(&len, sizeof(unsigned short int), 1, queue_file) == 1) {
char devpath[len];
/* use fread to skip, fseek might drop buffered data */
if (fread(devpath, 1, len, queue_file) == len)
return len;
}
return -1;
}
ssize_t udev_queue_read_devpath(FILE *queue_file, char *devpath, size_t size)
{
unsigned short int read_bytes = 0;
unsigned short int len;
if (fread(&len, sizeof(unsigned short int), 1, queue_file) != 1)
return -1;
read_bytes = (len < size - 1) ? len : size - 1;
if (fread(devpath, 1, read_bytes, queue_file) != read_bytes)
return -1;
devpath[read_bytes] = '\0';
/* if devpath was too long, skip unread characters */
if (read_bytes != len) {
unsigned short int skip_bytes = len - read_bytes;
char buf[skip_bytes];
if (fread(buf, 1, skip_bytes, queue_file) != skip_bytes)
return -1;
}
return read_bytes;
}
static FILE *open_queue_file(struct udev_queue *udev_queue, unsigned long long int *seqnum_start)
{
char filename[UTIL_PATH_SIZE];
unsigned long long int seqnum;
int fd;
char buf[32];
ssize_t len;
FILE *queue_file;
if (udev_queue == NULL)
return -EINVAL;
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue->udev), "/.udev/uevent_seqnum", NULL);
fd = open(filename, O_RDONLY);
if (fd < 0)
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue->udev), "/.udev/queue.bin", NULL);
queue_file = fopen(filename, "r");
if (queue_file == NULL)
return NULL;
if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) {
err(udev_queue->udev, "corrupt queue file\n");
fclose(queue_file);
return NULL;
}
return queue_file;
}
unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
{
unsigned long long int seqnum_udev;
FILE *queue_file;
queue_file = open_queue_file(udev_queue, &seqnum_udev);
if (queue_file == NULL)
return 0;
len = read(fd, buf, sizeof(buf));
close(fd);
if (len <= 2)
return 0;
buf[len-1] = '\0';
seqnum = strtoull(buf, NULL, 10);
dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
udev_queue->last_seen_udev_seqnum = seqnum;
return seqnum;
while (1) {
unsigned long long int seqnum;
ssize_t devpath_len;
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
break;
devpath_len = udev_queue_skip_devpath(queue_file);
if (devpath_len < 0)
break;
if (devpath_len > 0)
seqnum_udev = seqnum;
}
fclose(queue_file);
return seqnum_udev;
}
int udev_queue_get_udev_is_active(struct udev_queue *udev_queue)
{
char filename[UTIL_PATH_SIZE];
struct stat statbuf;
unsigned long long int seqnum_start;
FILE *queue_file;
if (udev_queue == NULL)
queue_file = open_queue_file(udev_queue, &seqnum_start);
if (queue_file == NULL)
return 0;
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue->udev), "/.udev/uevent_seqnum", NULL);
if (stat(filename, &statbuf) == 0)
return 1;
return 0;
fclose(queue_file);
return 1;
}
int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
{
char queuename[UTIL_PATH_SIZE];
struct stat statbuf;
unsigned long long int seqnum_kernel;
unsigned long long int seqnum_udev = 0;
int queued = 0;
int is_empty = 0;
FILE *queue_file;
if (udev_queue == NULL)
return -EINVAL;
util_strscpyl(queuename, sizeof(queuename), udev_get_dev_path(udev_queue->udev), "/.udev/queue", NULL);
if (stat(queuename, &statbuf) == 0) {
queue_file = open_queue_file(udev_queue, &seqnum_udev);
if (queue_file == NULL)
return 1;
while (1) {
unsigned long long int seqnum;
ssize_t devpath_len;
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
break;
devpath_len = udev_queue_skip_devpath(queue_file);
if (devpath_len < 0)
break;
if (devpath_len > 0) {
queued++;
seqnum_udev = seqnum;
} else {
queued--;
}
}
if (queued > 0) {
dbg(udev_queue->udev, "queue is not empty\n");
return 0;
goto out;
}
seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
dbg(udev_queue->udev, "queue is empty\n");
return 1;
if (seqnum_udev < seqnum_kernel) {
dbg(udev_queue->udev, "queue is empty but kernel events still pending [%llu]<->[%llu]\n",
seqnum_kernel, seqnum_udev);
goto out;
}
/* update udev seqnum, and check if udev is still running */
if (udev_queue_get_udev_seqnum(udev_queue) == 0)
if (!udev_queue_get_udev_is_active(udev_queue))
return 1;
if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
dbg(udev_queue->udev, "queue is empty\n");
dbg(udev_queue->udev, "queue is empty\n");
is_empty = 1;
out:
fclose(queue_file);
return is_empty;
}
int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
unsigned long long int start, unsigned long long int end)
{
unsigned long long int seqnum = 0;
ssize_t devpath_len;
int unfinished;
FILE *queue_file;
if (udev_queue == NULL)
return -EINVAL;
queue_file = open_queue_file(udev_queue, &seqnum);
if (queue_file == NULL)
return 1;
if (start < seqnum)
start = seqnum;
if (start > end)
return 1;
if (end - start > INT_MAX - 1)
return -EOVERFLOW;
unfinished = (end - start) + 1;
while (unfinished > 0) {
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
break;
devpath_len = udev_queue_skip_devpath(queue_file);
if (devpath_len < 0)
break;
if (devpath_len == 0) {
if (seqnum >= start && seqnum <= end)
unfinished--;
}
}
dbg(udev_queue->udev, "queue is empty, but kernel events still pending [%llu]<->[%llu]\n",
seqnum_kernel, udev_queue->last_seen_udev_seqnum);
return 0;
fclose(queue_file);
return (unfinished == 0);
}
int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
{
char filename[UTIL_PATH_SIZE];
struct stat statbuf;
if (udev_queue == NULL)
return -EINVAL;
/* did it reach the queue? */
if (seqnum > udev_queue->last_seen_udev_seqnum)
if (seqnum > udev_queue_get_udev_seqnum(udev_queue))
return 0;
/* is it still in the queue? */
snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
udev_get_dev_path(udev_queue->udev), seqnum);
if (lstat(filename, &statbuf) == 0)
if (!udev_queue_get_seqnum_sequence_is_finished(udev_queue, seqnum, seqnum))
return 0;
dbg(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
return 1;
}
struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
{
char path[UTIL_PATH_SIZE];
DIR *dir;
struct dirent *dent;
unsigned long long int seqnum;
FILE *queue_file;
if (udev_queue == NULL)
return NULL;
udev_list_cleanup_entries(udev_queue->udev, &udev_queue->queue_list);
util_strscpyl(path, sizeof(path), udev_get_dev_path(udev_queue->udev), "/.udev/queue", NULL);
dir = opendir(path);
if (dir == NULL)
queue_file = open_queue_file(udev_queue, &seqnum);
if (queue_file == NULL)
return NULL;
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
while (1) {
char syspath[UTIL_PATH_SIZE];
char *s;
size_t l;
ssize_t len;
char seqnum_str[32];
struct udev_list_entry *list_entry;
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
break;
snprintf(seqnum_str, sizeof(seqnum_str), "%llu", seqnum);
if (dent->d_name[0] == '.')
continue;
s = syspath;
l = util_strpcpyl(&s, sizeof(syspath), udev_get_sys_path(udev_queue->udev), NULL);
len = readlinkat(dirfd(dir), dent->d_name, s, l);
if (len < 0 || (size_t)len >= l)
continue;
s[len] = '\0';
dbg(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
udev_list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, dent->d_name, 0, 0);
len = udev_queue_read_devpath(queue_file, s, l);
if (len < 0)
break;
if (len > 0) {
udev_list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, seqnum_str, 0, 0);
} else {
udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_queue->queue_list)) {
if (strcmp(seqnum_str, udev_list_entry_get_value(list_entry)) == 0) {
udev_list_entry_delete(list_entry);
break;
}
}
}
}
closedir(dir);
fclose(queue_file);
return udev_list_get_entry(&udev_queue->queue_list);
}
@ -259,23 +399,3 @@ struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev
closedir(dir);
return udev_list_get_entry(&udev_queue->failed_list);
}
int udev_queue_export_udev_seqnum(struct udev_queue *udev_queue, unsigned long long int seqnum)
{
return -1;
}
int udev_queue_export_device_queued(struct udev_queue *udev_queue, struct udev_device *udev_device)
{
return -1;
}
int udev_queue_export_device_finished(struct udev_queue *udev_queue, struct udev_device *udev_device)
{
return -1;
}
int udev_queue_export_device_failed(struct udev_queue *udev_queue, struct udev_device *udev_device)
{
return -1;
}

2
udev/lib/libudev.h
View File

@ -115,6 +115,8 @@ unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
int udev_queue_get_udev_is_active(struct udev_queue *udev_queue);
int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue);
int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum);
int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
unsigned long long int start, unsigned long long int end);
struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue);
struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue);
#endif

22
udev/udevadm-settle.c
View File

@ -173,24 +173,16 @@ int udevadm_settle(struct udev *udev, int argc, char *argv[])
}
while (!is_timeout) {
/* exit if queue is empty */
if (udev_queue_get_queue_is_empty(udev_queue))
break;
/* if asked for, wait for a specific sequence of events */
if (start > 0) {
unsigned long long seq;
int finished;
finished = 0;
for (seq = start; seq <= end; seq++) {
finished = udev_queue_get_seqnum_is_finished(udev_queue, seq);
if (!finished)
break;
}
if (finished)
/* if asked for, wait for a specific sequence of events */
if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1)
break;
} else {
/* exit if queue is empty */
if (udev_queue_get_queue_is_empty(udev_queue))
break;
}
usleep(1000 * 1000 / LOOP_PER_SECOND);
}

154
udev/udevd.c
View File

@ -65,6 +65,7 @@ static void reap_sigchilds(void);
static int debug_trace;
static struct udev_rules *rules;
static struct udev_queue_export *udev_queue_export;
static struct udev_ctrl *udev_ctrl;
static struct udev_monitor *kernel_monitor;
static volatile sig_atomic_t sigchilds_waiting;
@ -78,12 +79,6 @@ static int max_childs;
static int childs;
static struct udev_list_node event_list;
enum event_state {
EVENT_QUEUED,
EVENT_FINISHED,
EVENT_FAILED,
};
static struct udev_event *node_to_event(struct udev_list_node *node)
{
char *event;
@ -93,76 +88,15 @@ static struct udev_event *node_to_event(struct udev_list_node *node)
return (struct udev_event *)event;
}
static void export_event_state(struct udev_event *event, enum event_state state)
{
char filename[UTIL_PATH_SIZE];
char filename_failed[UTIL_PATH_SIZE];
char *s;
size_t l;
/* location of queue file */
snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
/* location of failed file */
s = filename_failed;
l = util_strpcpyl(&s, sizeof(filename_failed), udev_get_dev_path(event->udev), "/.udev/failed/", NULL);
util_path_encode(udev_device_get_devpath(event->dev), s, l);
switch (state) {
case EVENT_QUEUED:
if(unlink(filename_failed) == 0)
util_delete_path(event->udev, filename_failed);
util_create_path(event->udev, filename);
udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
symlink(udev_device_get_devpath(event->dev), filename);
udev_selinux_resetfscreatecon(event->udev);
break;
case EVENT_FINISHED:
if (udev_device_get_devpath_old(event->dev) != NULL) {
/* "move" event - rename failed file to current name, do not delete failed */
char filename_failed_old[UTIL_PATH_SIZE];
s = filename_failed_old;
l = util_strpcpyl(&s, sizeof(filename_failed_old), udev_get_dev_path(event->udev), "/.udev/failed/", NULL);
util_path_encode(udev_device_get_devpath_old(event->dev), s, l);
if (rename(filename_failed_old, filename_failed) == 0)
info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
} else {
if (unlink(filename_failed) == 0)
util_delete_path(event->udev, filename_failed);
}
unlink(filename);
/* clean up possibly empty queue directory */
if (udev_list_is_empty(&event_list))
util_delete_path(event->udev, filename);
break;
case EVENT_FAILED:
/* move failed event to the failed directory */
util_create_path(event->udev, filename_failed);
rename(filename, filename_failed);
/* clean up possibly empty queue directory */
if (udev_list_is_empty(&event_list))
util_delete_path(event->udev, filename);
break;
}
return;
}
static void event_queue_delete(struct udev_event *event)
{
udev_list_node_remove(&event->node);
/* mark as failed, if "add" event returns non-zero */
if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
export_event_state(event, EVENT_FAILED);
udev_queue_export_device_failed(udev_queue_export, event->dev);
else
export_event_state(event, EVENT_FINISHED);
udev_queue_export_device_finished(udev_queue_export, event->dev);
udev_device_unref(event->dev);
udev_event_unref(event);
@ -201,6 +135,7 @@ static void event_fork(struct udev_event *event)
switch (pid) {
case 0:
/* child */
udev_queue_export_unref(udev_queue_export);
udev_ctrl_unref(udev_ctrl);
logging_close();
logging_init("udevd-event");
@ -267,27 +202,12 @@ static void event_fork(struct udev_event *event)
static void event_queue_insert(struct udev_event *event)
{
char filename[UTIL_PATH_SIZE];
int fd;
event->queue_time = time(NULL);
export_event_state(event, EVENT_QUEUED);
udev_queue_export_device_queued(udev_queue_export, event->dev);
info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(event->udev), "/.udev/uevent_seqnum", NULL);
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
char str[32];
int len;
len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
write(fd, str, len);
close(fd);
}
udev_list_node_append(&event->node, &event_list);
run_exec_q = 1;
@ -637,59 +557,6 @@ static void reap_sigchilds(void)
}
}
static void cleanup_queue_dir(struct udev *udev)
{
char dirname[UTIL_PATH_SIZE];
char filename[UTIL_PATH_SIZE];
DIR *dir;
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/uevent_seqnum", NULL);
unlink(filename);
util_strscpyl(dirname, sizeof(dirname), udev_get_dev_path(udev), "/.udev/queue", NULL);
dir = opendir(dirname);
if (dir != NULL) {
while (1) {
struct dirent *dent;
dent = readdir(dir);
if (dent == NULL || dent->d_name[0] == '\0')
break;
if (dent->d_name[0] == '.')
continue;
unlinkat(dirfd(dir), dent->d_name, 0);
}
closedir(dir);
rmdir(dirname);
}
}
static void export_initial_seqnum(struct udev *udev)
{
char filename[UTIL_PATH_SIZE];
int fd;
char seqnum[32];
ssize_t len = 0;
util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev), "/kernel/uevent_seqnum", NULL);
fd = open(filename, O_RDONLY);
if (fd >= 0) {
len = read(fd, seqnum, sizeof(seqnum)-1);
close(fd);
}
if (len <= 0) {
strcpy(seqnum, "0\n");
len = 3;
}
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/uevent_seqnum", NULL);
util_create_path(udev, filename);
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
write(fd, seqnum, len);
close(fd);
}
}
static void startup_log(struct udev *udev)
{
FILE *f;
@ -837,8 +704,11 @@ int main(int argc, char *argv[])
goto exit;
}
udev_list_init(&event_list);
cleanup_queue_dir(udev);
export_initial_seqnum(udev);
udev_queue_export = udev_queue_export_new(udev);
if (udev_queue_export == NULL) {
err(udev, "error creating queue file\n");
goto exit;
}
if (daemonize) {
pid_t pid;
@ -1027,9 +897,11 @@ handle_signals:
settle_pid = 0;
}
}
cleanup_queue_dir(udev);
udev_queue_export_cleanup(udev_queue_export);
rc = 0;
exit:
udev_queue_export_unref(udev_queue_export);
udev_rules_unref(rules);
udev_ctrl_unref(udev_ctrl);
if (inotify_fd >= 0)