From: Alan Jenkins Date: Thu, 21 May 2009 20:22:37 +0000 (+0200) Subject: udevd: implement a more efficient queue file format X-Git-Tag: 174~1031 X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=f503f6b22fa54d1a65156a51d8b3311190c73ae5;hp=f9b3f88f71f5bdfb18aa4bfba00d72fa41fdf286;ds=sidebyside udevd: implement a more efficient queue file format 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 --- diff --git a/configure.ac b/configure.ac index a6b53dbe5..f1d008e00 100644 --- a/configure.ac +++ b/configure.ac @@ -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) diff --git a/udev/Makefile.am b/udev/Makefile.am index fa8279dd6..6cd2f23dc 100644 --- a/udev/Makefile.am +++ b/udev/Makefile.am @@ -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 diff --git a/udev/lib/exported_symbols b/udev/lib/exported_symbols index 24a659546..8e7749e48 100644 --- a/udev/lib/exported_symbols +++ b/udev/lib/exported_symbols @@ -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 diff --git a/udev/lib/libudev-private.h b/udev/lib/libudev-private.h index 9ec5e1aae..3eb3d7957 100644 --- a/udev/lib/libudev-private.h +++ b/udev/lib/libudev-private.h @@ -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 index 000000000..ddb1974db --- /dev/null +++ b/udev/lib/libudev-queue-export.c @@ -0,0 +1,473 @@ +/* + * 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. + */ + +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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); +} diff --git a/udev/lib/libudev-queue.c b/udev/lib/libudev-queue.c index 8dce6c314..cf1ddf3a0 100644 --- a/udev/lib/libudev-queue.c +++ b/udev/lib/libudev-queue.c @@ -2,6 +2,7 @@ * 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 @@ -17,6 +18,7 @@ #include #include #include +#include #include #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; -} diff --git a/udev/lib/libudev.h b/udev/lib/libudev.h index 9346eb4dd..9b51ea330 100644 --- a/udev/lib/libudev.h +++ b/udev/lib/libudev.h @@ -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 diff --git a/udev/udevadm-settle.c b/udev/udevadm-settle.c index 52d9c0b24..f1052aa14 100644 --- a/udev/udevadm-settle.c +++ b/udev/udevadm-settle.c @@ -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); } diff --git a/udev/udevd.c b/udev/udevd.c index 23d594f55..5ee61d2e2 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -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)