chiark / gitweb /
udevd: implement a more efficient queue file format
authorAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Thu, 21 May 2009 20:22:37 +0000 (22:22 +0200)
committerKay Sievers <kay.sievers@vrfy.org>
Thu, 21 May 2009 20:22:37 +0000 (22:22 +0200)
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>
configure.ac
udev/Makefile.am
udev/lib/exported_symbols
udev/lib/libudev-private.h
udev/lib/libudev-queue-export.c [new file with mode: 0644]
udev/lib/libudev-queue.c
udev/lib/libudev.h
udev/udevadm-settle.c
udev/udevd.c

index a6b53db..f1d008e 100644 (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)
index fa8279d..6cd2f23 100644 (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
index 24a6595..8e7749e 100644 (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
index 9ec5e1a..3eb3d79 100644 (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
diff --git a/udev/lib/libudev-queue-export.c b/udev/lib/libudev-queue-export.c
new file mode 100644 (file)
index 0000000..ddb1974
--- /dev/null
@@ -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);
+}
index 8dce6c3..cf1ddf3 100644 (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);
-       dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
        return seqnum;
 }
 
-unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
+unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
 {
-       char filename[UTIL_PATH_SIZE];
        unsigned long long int seqnum;
-       int fd;
-       char buf[32];
-       ssize_t len;
 
        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)
-               return 0;
-       len = read(fd, buf, sizeof(buf));
-       close(fd);
-       if (len <= 2)
-               return 0;
-       buf[len-1] = '\0';
-       seqnum = strtoull(buf, NULL, 10);
+
+       seqnum = udev_get_kernel_seqnum(udev_queue->udev);
        dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
-       udev_queue->last_seen_udev_seqnum = seqnum;
        return seqnum;
 }
 
-int udev_queue_get_udev_is_active(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];
-       struct stat statbuf;
+       FILE *queue_file;
 
-       if (udev_queue == NULL)
+       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;
-       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;
+
+       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)
+{
+       unsigned long long int seqnum_start;
+       FILE *queue_file;
+
+       queue_file = open_queue_file(udev_queue, &seqnum_start);
+       if (queue_file == NULL)
+               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;
-       }
-       /* 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");
-               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;
        }
-       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;
+
+       dbg(udev_queue->udev, "queue is empty\n");
+       is_empty = 1;
+
+out:
+       fclose(queue_file);
+       return is_empty;
 }
 
-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)
 {
-       char filename[UTIL_PATH_SIZE];
-       struct stat statbuf;
+       unsigned long long int seqnum = 0;
+       ssize_t devpath_len;
+       int unfinished;
+       FILE *queue_file;
 
        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)
+       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--;
+               }
+       }
+       fclose(queue_file);
+
+       return (unfinished == 0);
+}
+
+int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
+{
+       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;
-}
index 9346eb4..9b51ea3 100644 (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
index 52d9c0b..f1052aa 100644 (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);
        }
 
index 23d594f..5ee61d2 100644 (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)