X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibudev%2Flibudev-queue.c;h=ae0b415e368d9f6a31894e7a75018f028935d289;hp=15a7f558b1dff40f74eaf66cfd90a52cae6fc0f8;hb=93a1e66efd4b0f4cda29c467d20d0f7510c0b3a8;hpb=20bbd54f603994a3cc211d2795de16550882ed8d diff --git a/src/libudev/libudev-queue.c b/src/libudev/libudev-queue.c index 15a7f558b..ae0b415e3 100644 --- a/src/libudev/libudev-queue.c +++ b/src/libudev/libudev-queue.c @@ -1,14 +1,22 @@ -/* - * libudev - interface to udev device information - * - * Copyright (C) 2008 Kay Sievers - * Copyright (C) 2009 Alan Jenkins - * - * 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. - */ +/*** + This file is part of systemd. + + Copyright 2008-2012 Kay Sievers + Copyright 2009 Alan Jenkins + + systemd 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. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ #include #include @@ -16,10 +24,9 @@ #include #include #include -#include -#include #include #include +#include #include "libudev.h" #include "libudev-private.h" @@ -28,10 +35,7 @@ * SECTION:libudev-queue * @short_description: access to currently active events * - * The udev daemon processes events asynchronously. All events which do not have - * interdependencies run in parallel. This exports the current state of the - * event processing queue, and the current event sequence numbers from the kernel - * and the udev daemon. + * This exports the current state of the udev processing queue. */ /** @@ -42,7 +46,7 @@ struct udev_queue { struct udev *udev; int refcount; - struct udev_list queue_list; + int fd; }; /** @@ -61,12 +65,13 @@ _public_ struct udev_queue *udev_queue_new(struct udev *udev) if (udev == NULL) return NULL; - udev_queue = calloc(1, sizeof(struct udev_queue)); + udev_queue = new0(struct udev_queue, 1); if (udev_queue == NULL) return NULL; + udev_queue->refcount = 1; udev_queue->udev = udev; - udev_list_init(udev, &udev_queue->queue_list, false); + udev_queue->fd = -1; return udev_queue; } @@ -82,6 +87,7 @@ _public_ struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue) { if (udev_queue == NULL) return NULL; + udev_queue->refcount++; return udev_queue; } @@ -92,15 +98,20 @@ _public_ struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue) * * Drop a reference of a udev queue context. If the refcount reaches zero, * the resources of the queue context will be released. + * + * Returns: #NULL **/ _public_ struct udev_queue *udev_queue_unref(struct udev_queue *udev_queue) { if (udev_queue == NULL) return NULL; + udev_queue->refcount--; if (udev_queue->refcount > 0) - return udev_queue; - udev_list_cleanup(&udev_queue->queue_list); + return NULL; + + safe_close(udev_queue->fd); + free(udev_queue); return NULL; } @@ -120,143 +131,30 @@ _public_ struct udev *udev_queue_get_udev(struct udev_queue *udev_queue) return udev_queue->udev; } -unsigned long long int udev_get_kernel_seqnum(struct udev *udev) -{ - unsigned long long int seqnum; - int fd; - char buf[32]; - ssize_t len; - - fd = open("/sys/kernel/uevent_seqnum", O_RDONLY|O_CLOEXEC); - 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); - return seqnum; -} - /** * udev_queue_get_kernel_seqnum: * @udev_queue: udev queue context * - * Get the current kernel event sequence number. + * This function is deprecated. * - * Returns: the sequence number. + * Returns: 0. **/ _public_ 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); - return seqnum; -} - -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 = alloca(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 = alloca(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]; - FILE *queue_file; - - util_strscpyl(filename, sizeof(filename), "/run/udev/queue.bin", NULL); - queue_file = fopen(filename, "re"); - if (queue_file == NULL) - return NULL; - - if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) { - udev_err(udev_queue->udev, "corrupt queue file\n"); - fclose(queue_file); - return NULL; - } - - return queue_file; -} - /** * udev_queue_get_udev_seqnum: * @udev_queue: udev queue context * - * Get the last known udev event sequence number. + * This function is deprecated. * - * Returns: the sequence number. + * Returns: 0. **/ _public_ 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; - - for (;;) { - 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; + return 0; } /** @@ -269,15 +167,7 @@ _public_ unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *ud **/ _public_ 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; + return access("/run/udev/control", F_OK) >= 0; } /** @@ -290,48 +180,7 @@ _public_ int udev_queue_get_udev_is_active(struct udev_queue *udev_queue) **/ _public_ int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue) { - 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; - queue_file = open_queue_file(udev_queue, &seqnum_udev); - if (queue_file == NULL) - return 1; - - for (;;) { - 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) - goto out; - - seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue); - if (seqnum_udev < seqnum_kernel) - goto out; - - is_empty = 1; - -out: - fclose(queue_file); - return is_empty; + return access("/run/udev/queue", F_OK) < 0; } /** @@ -340,63 +189,15 @@ out: * @start: first event sequence number * @end: last event sequence number * - * Check if udev is currently processing any events in a given sequence number range. + * This function is deprecated, it just returns the result of + * udev_queue_get_queue_is_empty(). * - * Returns: a flag indicating if any of the sequence numbers in the given range is currently active. + * Returns: a flag indicating if udev is currently handling events. **/ _public_ 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; - 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) { - fclose(queue_file); - return 1; - } - if (end - start > INT_MAX - 1) { - fclose(queue_file); - return -EOVERFLOW; - } - - /* - * we might start with 0, and handle the initial seqnum - * only when we find an entry in the queue file - **/ - unfinished = end - start; - - do { - if (udev_queue_read_seqnum(queue_file, &seqnum) < 0) - break; - devpath_len = udev_queue_skip_devpath(queue_file); - if (devpath_len < 0) - break; - - /* - * we might start with an empty or re-build queue file, where - * the initial seqnum is not recorded as finished - */ - if (start == seqnum && devpath_len > 0) - unfinished++; - - if (devpath_len == 0) { - if (seqnum >= start && seqnum <= end) - unfinished--; - } - } while (unfinished > 0); - - fclose(queue_file); - - return (unfinished == 0); + return udev_queue_get_queue_is_empty(udev_queue); } /** @@ -404,69 +205,69 @@ _public_ int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_ * @udev_queue: udev queue context * @seqnum: sequence number * - * Check if udev is currently processing a given sequence number. + * This function is deprecated, it just returns the result of + * udev_queue_get_queue_is_empty(). * - * Returns: a flag indicating if the given sequence number is currently active. + * Returns: a flag indicating if udev is currently handling events. **/ _public_ 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; - - return 1; + return udev_queue_get_queue_is_empty(udev_queue); } /** * udev_queue_get_queued_list_entry: * @udev_queue: udev queue context * - * Get the first entry of the list of queued events. + * This function is deprecated. * - * Returns: a udev_list_entry. + * Returns: NULL. **/ _public_ struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue) { - unsigned long long int seqnum; - FILE *queue_file; + return NULL; +} - if (udev_queue == NULL) - return NULL; - udev_list_cleanup(&udev_queue->queue_list); +/** + * udev_queue_get_fd: + * @udev_queue: udev queue context + * + * Returns: a file descriptor to watch for a queue to become empty. + */ +_public_ int udev_queue_get_fd(struct udev_queue *udev_queue) { + int fd; + int r; - queue_file = open_queue_file(udev_queue, &seqnum); - if (queue_file == NULL) - return NULL; + if (udev_queue->fd >= 0) + return udev_queue->fd; + + fd = inotify_init1(IN_CLOEXEC); + if (fd < 0) + return -errno; - for (;;) { - 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); - - s = syspath; - l = util_strpcpy(&s, sizeof(syspath), "/sys"); - len = udev_queue_read_devpath(queue_file, s, l); - if (len < 0) - break; - - if (len > 0) { - udev_list_entry_add(&udev_queue->queue_list, syspath, seqnum_str); - } 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; - } - } - } + r = inotify_add_watch(fd, "/run/udev" , IN_DELETE); + if (r < 0) { + r = -errno; + close(fd); + return r; } - fclose(queue_file); - return udev_list_get_entry(&udev_queue->queue_list); + udev_queue->fd = fd; + return fd; +} + +/** + * udev_queue_flush: + * @udev_queue: udev queue context + * + * Returns: the result of clearing the watch for queue changes. + */ +_public_ int udev_queue_flush(struct udev_queue *udev_queue) { + if (udev_queue->fd < 0) + return -EINVAL; + + return flush_fd(udev_queue->fd); } + +__asm__(".symver udev_queue_flush,udev_queue_flush@LIBUDEV_183"); +__asm__(".symver udev_queue_get_fd,udev_queue_get_fd@LIBUDEV_183");