--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ 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 <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <limits.h>
+#include <sys/file.h>
+
+#include "util.h"
+#include "lockfile-util.h"
+#include "fileio.h"
+
+int make_lock_file(const char *p, int operation, LockFile *ret) {
+ _cleanup_close_ int fd = -1;
+ _cleanup_free_ char *t = NULL;
+ int r;
+
+ /*
+ * We use UNPOSIX locks if they are available. They have nice
+ * semantics, and are mostly compatible with NFS. However,
+ * they are only available on new kernels. When we detect we
+ * are running on an older kernel, then we fall back to good
+ * old BSD locks. They also have nice semantics, but are
+ * slightly problematic on NFS, where they are upgraded to
+ * POSIX locks, even though locally they are orthogonal to
+ * POSIX locks.
+ */
+
+ t = strdup(p);
+ if (!t)
+ return -ENOMEM;
+
+ for (;;) {
+ struct flock fl = {
+ .l_type = (operation & ~LOCK_NB) == LOCK_EX ? F_WRLCK : F_RDLCK,
+ .l_whence = SEEK_SET,
+ };
+ struct stat st;
+
+ fd = open(p, O_CREAT|O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NOCTTY, 0600);
+ if (fd < 0)
+ return -errno;
+
+ r = fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl);
+ if (r < 0) {
+
+ /* If the kernel is too old, use good old BSD locks */
+ if (errno == EINVAL)
+ r = flock(fd, operation);
+
+ if (r < 0)
+ return errno == EAGAIN ? -EBUSY : -errno;
+ }
+
+ /* If we acquired the lock, let's check if the file
+ * still exists in the file system. If not, then the
+ * previous exclusive owner removed it and then closed
+ * it. In such a case our acquired lock is worthless,
+ * hence try again. */
+
+ r = fstat(fd, &st);
+ if (r < 0)
+ return -errno;
+ if (st.st_nlink > 0)
+ break;
+
+ fd = safe_close(fd);
+ }
+
+ ret->path = t;
+ ret->fd = fd;
+ ret->operation = operation;
+
+ fd = -1;
+ t = NULL;
+
+ return r;
+}
+
+int make_lock_file_for(const char *p, int operation, LockFile *ret) {
+ const char *fn;
+ char *t;
+
+ assert(p);
+ assert(ret);
+
+ fn = basename(p);
+ if (!filename_is_valid(fn))
+ return -EINVAL;
+
+ t = newa(char, strlen(p) + 2 + 4 + 1);
+ stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), ".lck");
+
+ return make_lock_file(t, operation, ret);
+}
+
+void release_lock_file(LockFile *f) {
+ int r;
+
+ if (!f)
+ return;
+
+ if (f->path) {
+
+ /* If we are the exclusive owner we can safely delete
+ * the lock file itself. If we are not the exclusive
+ * owner, we can try becoming it. */
+
+ if (f->fd >= 0 &&
+ (f->operation & ~LOCK_NB) == LOCK_SH) {
+ static const struct flock fl = {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ };
+
+ r = fcntl(f->fd, F_OFD_SETLK, &fl);
+ if (r < 0 && errno == EINVAL)
+ r = flock(f->fd, LOCK_EX|LOCK_NB);
+
+ if (r >= 0)
+ f->operation = LOCK_EX|LOCK_NB;
+ }
+
+ if ((f->operation & ~LOCK_NB) == LOCK_EX)
+ unlink_noerrno(f->path);
+
+ free(f->path);
+ f->path = NULL;
+ }
+
+ f->fd = safe_close(f->fd);
+ f->operation = 0;
+}
--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+ This file is part of systemd.
+
+ Copyright 2011 Lennart Poettering
+
+ 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 <http://www.gnu.org/licenses/>.
+***/
+
+#include "macro.h"
+#include "missing.h"
+
+typedef struct LockFile {
+ char *path;
+ int fd;
+ int operation;
+} LockFile;
+
+int make_lock_file(const char *p, int operation, LockFile *ret);
+int make_lock_file_for(const char *p, int operation, LockFile *ret);
+void release_lock_file(LockFile *f);
+
+#define _cleanup_release_lock_file_ _cleanup_(release_lock_file)
+
+#define LOCK_FILE_INIT { .fd = -1, .path = NULL }
***/
#include "time-util.h"
+#include "lockfile-util.h"
#include "hashmap.h"
typedef enum ImageType {
#include "util.h"
#include "process-util.h"
+#include "lockfile-util.h"
#include "mkdir.h"
#include "btrfs-util.h"
#include "path-util.h"
return read_attr_fd(fd, ret);
}
-int make_lock_file(const char *p, int operation, LockFile *ret) {
- _cleanup_close_ int fd = -1;
- _cleanup_free_ char *t = NULL;
- int r;
-
- /*
- * We use UNPOSIX locks if they are available. They have nice
- * semantics, and are mostly compatible with NFS. However,
- * they are only available on new kernels. When we detect we
- * are running on an older kernel, then we fall back to good
- * old BSD locks. They also have nice semantics, but are
- * slightly problematic on NFS, where they are upgraded to
- * POSIX locks, even though locally they are orthogonal to
- * POSIX locks.
- */
-
- t = strdup(p);
- if (!t)
- return -ENOMEM;
-
- for (;;) {
- struct flock fl = {
- .l_type = (operation & ~LOCK_NB) == LOCK_EX ? F_WRLCK : F_RDLCK,
- .l_whence = SEEK_SET,
- };
- struct stat st;
-
- fd = open(p, O_CREAT|O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NOCTTY, 0600);
- if (fd < 0)
- return -errno;
-
- r = fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl);
- if (r < 0) {
-
- /* If the kernel is too old, use good old BSD locks */
- if (errno == EINVAL)
- r = flock(fd, operation);
-
- if (r < 0)
- return errno == EAGAIN ? -EBUSY : -errno;
- }
-
- /* If we acquired the lock, let's check if the file
- * still exists in the file system. If not, then the
- * previous exclusive owner removed it and then closed
- * it. In such a case our acquired lock is worthless,
- * hence try again. */
-
- r = fstat(fd, &st);
- if (r < 0)
- return -errno;
- if (st.st_nlink > 0)
- break;
-
- fd = safe_close(fd);
- }
-
- ret->path = t;
- ret->fd = fd;
- ret->operation = operation;
-
- fd = -1;
- t = NULL;
-
- return r;
-}
-
-int make_lock_file_for(const char *p, int operation, LockFile *ret) {
- const char *fn;
- char *t;
-
- assert(p);
- assert(ret);
-
- fn = basename(p);
- if (!filename_is_valid(fn))
- return -EINVAL;
-
- t = newa(char, strlen(p) + 2 + 4 + 1);
- stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), ".lck");
-
- return make_lock_file(t, operation, ret);
-}
-
-void release_lock_file(LockFile *f) {
- int r;
-
- if (!f)
- return;
-
- if (f->path) {
-
- /* If we are the exclusive owner we can safely delete
- * the lock file itself. If we are not the exclusive
- * owner, we can try becoming it. */
-
- if (f->fd >= 0 &&
- (f->operation & ~LOCK_NB) == LOCK_SH) {
- static const struct flock fl = {
- .l_type = F_WRLCK,
- .l_whence = SEEK_SET,
- };
-
- r = fcntl(f->fd, F_OFD_SETLK, &fl);
- if (r < 0 && errno == EINVAL)
- r = flock(f->fd, LOCK_EX|LOCK_NB);
-
- if (r >= 0)
- f->operation = LOCK_EX|LOCK_NB;
- }
-
- if ((f->operation & ~LOCK_NB) == LOCK_EX)
- unlink_noerrno(f->path);
-
- free(f->path);
- f->path = NULL;
- }
-
- f->fd = safe_close(f->fd);
- f->operation = 0;
-}
-
static size_t nul_length(const uint8_t *p, size_t sz) {
size_t n = 0;
int read_attr_fd(int fd, unsigned *ret);
int read_attr_path(const char *p, unsigned *ret);
-typedef struct LockFile {
- char *path;
- int fd;
- int operation;
-} LockFile;
-
-int make_lock_file(const char *p, int operation, LockFile *ret);
-int make_lock_file_for(const char *p, int operation, LockFile *ret);
-void release_lock_file(LockFile *f);
-
-#define _cleanup_release_lock_file_ _cleanup_(release_lock_file)
-
-#define LOCK_FILE_INIT { .fd = -1, .path = NULL }
-
#define RLIMIT_MAKE_CONST(lim) ((struct rlimit) { lim, lim })
ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length);
~ianmdlvl / elogind.git / commitdiff