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lockfile-util: Drop flock() fallback

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UNPOSIX locks were added in 3.15 which is now our minimal kernel
version, so let's drop the fallback.
This commit is contained in:
Daan De Meyer
2023-03-10 10:14:41 +01:00
parent 44777d7ad6
commit ed70a34ec0
1 changed files with 5 additions and 24 deletions
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src/shared/lockfile-util.c
+5 -24
View File
@@ -18,18 +18,11 @@
int make_lock_file(const char *p, int operation, LockFile *ret) {
_cleanup_close_ int fd = -EBADF;
_cleanup_free_ char *t = NULL;
int r;
assert(p);
assert(ret);
/*
* 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.
*/
/* We use UNPOSIX locks as they have nice semantics, and are mostly compatible with NFS. */
t = strdup(p);
if (!t)
@@ -46,14 +39,8 @@ int make_lock_file(const char *p, int operation, LockFile *ret) {
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 || ERRNO_IS_NOT_SUPPORTED(errno))
r = flock(fd, operation);
if (r < 0)
return errno == EAGAIN ? -EBUSY : -errno;
}
if (fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl) < 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
@@ -73,7 +60,7 @@ int make_lock_file(const char *p, int operation, LockFile *ret) {
.operation = operation,
};
return r;
return 0;
}
int make_lock_file_for(const char *p, int operation, LockFile *ret) {
@@ -99,8 +86,6 @@ int make_lock_file_for(const char *p, int operation, LockFile *ret) {
}
void release_lock_file(LockFile *f) {
int r;
if (!f)
return;
@@ -117,11 +102,7 @@ void release_lock_file(LockFile *f) {
.l_whence = SEEK_SET,
};
r = fcntl(f->fd, F_OFD_SETLK, &fl);
if (r < 0 && (errno == EINVAL || ERRNO_IS_NOT_SUPPORTED(errno)))
r = flock(f->fd, LOCK_EX|LOCK_NB);
if (r >= 0)
if (fcntl(f->fd, F_OFD_SETLK, &fl) >= 0)
f->operation = LOCK_EX|LOCK_NB;
}