TODO list for agedu
===================
-Before it's non-embarrassingly releasable:
-
- - now we have a configure framework, actually use it to:
- * configure use of stat64
- * configure use of Linux syscall magic replacing readdir
- + later glibcs have fdopendir, hooray! So we can use that
- too, if it's available and O_NOATIME is too.
-
Future possibilities:
+ - integrate more usefully with the output of configure. It's
+ generating oodles of automatic boilerplate in config.h and I'm
+ sure three quarters of it _ought_ to be usable to add
+ portability, if only I had the gumption to actually pay attention
+ to all those HAVE_FOO macros it's defined for me.
+
- IPv6 support in the HTTP server
* of course, Linux magic auth can still work in this context; we
merely have to be prepared to open one of /proc/net/tcp or
#include <sys/stat.h>
#include <unistd.h>
+#include "agedu.h"
#include "du.h"
#include "alloc.h"
-#ifdef __linux__
+#if !defined __linux__ || defined HAVE_FDOPENDIR
/*
- * On Linux, we have the O_NOATIME flag. This means we can read
- * the contents of directories without affecting their atimes,
- * which enables us to at least try to include them in the age
- * display rather than exempting them.
- *
- * Unfortunately, opendir() doesn't let us open a directory with
- * O_NOATIME. In later glibcs we can open one manually using
- * open() and then use fdopendir() to translate the fd into a
- * POSIX dir handle; in earlier glibcs fdopendir() is not
- * available, so we have no option but to talk directly to the
- * kernel system call interface which underlies the POSIX
- * opendir/readdir machinery.
+ * Wrappers around POSIX opendir, readdir and closedir, which
+ * permit me to replace them with different wrappers in special
+ * circumstances.
*/
-#define __KERNEL__
-#include <unistd.h>
-#include <fcntl.h>
-#include <linux/types.h>
-#include <linux/dirent.h>
-#include <linux/unistd.h>
-
-_syscall3(int, getdents, uint, fd, struct dirent *, dirp, uint, count)
-
-typedef struct {
- int fd;
- struct dirent data[32];
- struct dirent *curr;
- int pos, endpos;
-} dirhandle;
+#include <dirent.h>
+typedef DIR *dirhandle;
int open_dir(const char *path, dirhandle *dh)
{
- dh->fd = open(path, O_RDONLY | O_NOATIME | O_DIRECTORY);
- if (dh->fd < 0) {
+#if defined O_NOATIME && defined HAVE_FDOPENDIR
+
+ /*
+ * On Linux, we have the O_NOATIME flag. This means we can
+ * read the contents of directories without affecting their
+ * atimes, which enables us to at least try to include them in
+ * the age display rather than exempting them.
+ *
+ * Unfortunately, opendir() doesn't let us open a directory
+ * with O_NOATIME. So instead, we have to open the directory
+ * with vanilla open(), and then use fdopendir() to translate
+ * the fd into a POSIX dir handle.
+ */
+ int fd;
+
+ fd = open(path, O_RDONLY | O_NONBLOCK | O_NOCTTY | O_LARGEFILE |
+ O_NOATIME | O_DIRECTORY);
+ if (fd < 0) {
/*
* Opening a file with O_NOATIME is not unconditionally
* permitted by the Linux kernel. As far as I can tell,
* we receive EPERM.
*/
if (errno == EPERM)
- dh->fd = open(path, O_RDONLY | O_DIRECTORY);
+ fd = open(path, O_RDONLY | O_NONBLOCK | O_NOCTTY |
+ O_LARGEFILE | O_DIRECTORY);
+ if (fd < 0)
+ return -1;
+ }
+
+ *dh = fdopendir(fd);
+#else
+ *dh = opendir(path);
+#endif
+
+ if (!*dh)
+ return -1;
+ return 0;
+}
+
+const char *read_dir(dirhandle *dh)
+{
+ struct dirent *de = readdir(*dh);
+ return de ? de->d_name : NULL;
+}
+
+void close_dir(dirhandle *dh)
+{
+ closedir(*dh);
+}
+
+#else /* defined __linux__ && !defined HAVE_FDOPENDIR */
+
+/*
+ * Earlier versions of glibc do not have fdopendir(). Therefore,
+ * if we are on Linux and still wish to make use of O_NOATIME, we
+ * have no option but to talk directly to the kernel system call
+ * interface which underlies the POSIX opendir/readdir machinery.
+ */
+
+#define __KERNEL__
+#include <unistd.h>
+#include <fcntl.h>
+#include <linux/types.h>
+#include <linux/dirent.h>
+#include <linux/unistd.h>
+
+_syscall3(int, getdents, uint, fd, struct dirent *, dirp, uint, count)
+
+typedef struct {
+ int fd;
+ struct dirent data[32];
+ struct dirent *curr;
+ int pos, endpos;
+} dirhandle;
+
+int open_dir(const char *path, dirhandle *dh)
+{
+ /*
+ * As above, we try with O_NOATIME and then fall back to
+ * trying without it.
+ */
+ dh->fd = open(path, O_RDONLY | O_NONBLOCK | O_NOCTTY | O_LARGEFILE |
+ O_NOATIME | O_DIRECTORY);
+ if (dh->fd < 0) {
+ if (errno == EPERM)
+ dh->fd = open(path, O_RDONLY | O_NONBLOCK | O_NOCTTY |
+ O_LARGEFILE | O_DIRECTORY);
if (dh->fd < 0)
return -1;
}
close(dh->fd);
}
-#else /* __linux__ */
-
-/*
- * This branch of the ifdef is a simple exercise of ordinary POSIX
- * opendir/readdir.
- */
-
-#include <dirent.h>
-typedef DIR *dirhandle;
-
-int open_dir(const char *path, dirhandle *dh)
-{
- *dh = opendir(path);
- if (!*dh)
- return -1;
- return 0;
-}
-
-const char *read_dir(dirhandle *dh)
-{
- struct dirent *de = readdir(*dh);
- return de ? de->d_name : NULL;
-}
-
-void close_dir(dirhandle *dh)
-{
- closedir(*dh);
-}
-
-#endif
+#endif /* !defined __linux__ || defined HAVE_FDOPENDIR */
static int str_cmp(const void *av, const void *bv)
{
{
const char *name;
dirhandle d;
- struct stat64 st;
+ STRUCT_STAT st;
char **names;
size_t i, nnames, namesize;
- if (lstat64(*path, &st) < 0) {
+ if (LSTAT(*path, &st) < 0) {
fprintf(stderr, "%s: lstat: %s\n", *path, strerror(errno));
return;
}
~mdw / sgt / agedu / commitdiff