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authorLennart Poettering <lennart@poettering.net>2014-03-18 19:22:43 +0100
committerLennart Poettering <lennart@poettering.net>2014-03-18 19:31:34 +0100
commit03e334a1c7dc8c20c38902aa039440763acc9b17 (patch)
treebc30b522de8ef9c251bf3ff2fe2d52c92dd8b1ea /src/shared/util.c
parent9459781ee66eb57709c8b8701701365ba60a9f1c (diff)
util: replace close_nointr_nofail() by a more useful safe_close()
safe_close() automatically becomes a NOP when a negative fd is passed, and returns -1 unconditionally. This makes it easy to write lines like this: fd = safe_close(fd); Which will close an fd if it is open, and reset the fd variable correctly. By making use of this new scheme we can drop a > 200 lines of code that was required to test for non-negative fds or to reset the closed fd variable afterwards.
Diffstat (limited to 'src/shared/util.c')
-rw-r--r--src/shared/util.c76
1 files changed, 37 insertions, 39 deletions
diff --git a/src/shared/util.c b/src/shared/util.c
index 75870fcbe2..a8c4523905 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -183,13 +183,22 @@ int close_nointr(int fd) {
return -errno;
}
-void close_nointr_nofail(int fd) {
- PROTECT_ERRNO;
+int safe_close(int fd) {
+
+ /*
+ * Like close_nointr() but cannot fail. Guarantees errno is
+ * unchanged. Is a NOP with negative fds passed, and returns
+ * -1, so that it can be used in this syntax:
+ *
+ * fd = safe_close(fd);
+ */
- /* like close_nointr() but cannot fail, and guarantees errno
- * is unchanged */
+ if (fd >= 0) {
+ PROTECT_ERRNO;
+ assert_se(close_nointr(fd) == 0);
+ }
- assert_se(close_nointr(fd) == 0);
+ return -1;
}
void close_many(const int fds[], unsigned n_fd) {
@@ -198,7 +207,7 @@ void close_many(const int fds[], unsigned n_fd) {
assert(fds || n_fd <= 0);
for (i = 0; i < n_fd; i++)
- close_nointr_nofail(fds[i]);
+ safe_close(fds[i]);
}
int unlink_noerrno(const char *path) {
@@ -1693,16 +1702,13 @@ finish:
}
int reset_terminal(const char *name) {
- int fd, r;
+ _cleanup_close_ int fd = -1;
fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
if (fd < 0)
return fd;
- r = reset_terminal_fd(fd, true);
- close_nointr_nofail(fd);
-
- return r;
+ return reset_terminal_fd(fd, true);
}
int open_terminal(const char *name, int mode) {
@@ -1741,12 +1747,12 @@ int open_terminal(const char *name, int mode) {
r = isatty(fd);
if (r < 0) {
- close_nointr_nofail(fd);
+ safe_close(fd);
return -errno;
}
if (!r) {
- close_nointr_nofail(fd);
+ safe_close(fd);
return -ENOTTY;
}
@@ -1935,11 +1941,10 @@ int acquire_terminal(
* ended our handle will be dead. It's important that
* we do this after sleeping, so that we don't enter
* an endless loop. */
- close_nointr_nofail(fd);
+ safe_close(fd);
}
- if (notify >= 0)
- close_nointr_nofail(notify);
+ safe_close(notify);
r = reset_terminal_fd(fd, true);
if (r < 0)
@@ -1948,11 +1953,8 @@ int acquire_terminal(
return fd;
fail:
- if (fd >= 0)
- close_nointr_nofail(fd);
-
- if (notify >= 0)
- close_nointr_nofail(notify);
+ safe_close(fd);
+ safe_close(notify);
return r;
}
@@ -2262,7 +2264,7 @@ int make_stdio(int fd) {
t = dup3(fd, STDERR_FILENO, 0);
if (fd >= 3)
- close_nointr_nofail(fd);
+ safe_close(fd);
if (r < 0 || s < 0 || t < 0)
return -errno;
@@ -2640,7 +2642,7 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct
d = fdopendir(fd);
if (!d) {
- close_nointr_nofail(fd);
+ safe_close(fd);
return errno == ENOENT ? 0 : -errno;
}
@@ -2736,7 +2738,7 @@ int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root
assert(fd >= 0);
if (fstatfs(fd, &s) < 0) {
- close_nointr_nofail(fd);
+ safe_close(fd);
return -errno;
}
@@ -2745,7 +2747,7 @@ int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root
* non-state data */
if (!is_temporary_fs(&s)) {
log_error("Attempted to remove disk file system, and we can't allow that.");
- close_nointr_nofail(fd);
+ safe_close(fd);
return -EPERM;
}
@@ -2791,13 +2793,13 @@ static int rm_rf_internal(const char *path, bool only_dirs, bool delete_root, bo
if (!dangerous) {
if (fstatfs(fd, &s) < 0) {
- close_nointr_nofail(fd);
+ safe_close(fd);
return -errno;
}
if (!is_temporary_fs(&s)) {
log_error("Attempted to remove disk file system, and we can't allow that.");
- close_nointr_nofail(fd);
+ safe_close(fd);
return -EPERM;
}
}
@@ -3318,7 +3320,7 @@ char *ellipsize(const char *s, size_t length, unsigned percent) {
}
int touch(const char *path) {
- int fd;
+ _cleanup_close_ int fd;
assert(path);
@@ -3330,7 +3332,6 @@ int touch(const char *path) {
if (fd < 0)
return -errno;
- close_nointr_nofail(fd);
return 0;
}
@@ -3493,7 +3494,7 @@ DIR *xopendirat(int fd, const char *name, int flags) {
d = fdopendir(nfd);
if (!d) {
- close_nointr_nofail(nfd);
+ safe_close(nfd);
return NULL;
}
@@ -3987,16 +3988,13 @@ int terminal_vhangup_fd(int fd) {
}
int terminal_vhangup(const char *name) {
- int fd, r;
+ _cleanup_close_ int fd;
fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
if (fd < 0)
return fd;
- r = terminal_vhangup_fd(fd);
- close_nointr_nofail(fd);
-
- return r;
+ return terminal_vhangup_fd(fd);
}
int vt_disallocate(const char *name) {
@@ -4023,7 +4021,7 @@ int vt_disallocate(const char *name) {
"\033[H" /* move home */
"\033[2J", /* clear screen */
10, false);
- close_nointr_nofail(fd);
+ safe_close(fd);
return 0;
}
@@ -4044,7 +4042,7 @@ int vt_disallocate(const char *name) {
return fd;
r = ioctl(fd, VT_DISALLOCATE, u);
- close_nointr_nofail(fd);
+ safe_close(fd);
if (r >= 0)
return 0;
@@ -4063,7 +4061,7 @@ int vt_disallocate(const char *name) {
"\033[H" /* move home */
"\033[3J", /* clear screen including scrollback, requires Linux 2.6.40 */
10, false);
- close_nointr_nofail(fd);
+ safe_close(fd);
return 0;
}
@@ -5640,7 +5638,7 @@ int on_ac_power(void) {
if (n != 6 || memcmp(contents, "Mains\n", 6))
continue;
- close_nointr_nofail(fd);
+ safe_close(fd);
fd = openat(device, "online", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0) {
if (errno == ENOENT)