libmount: scandirat based mnt_table_parse_dir implementation

In comment of `mnt_table_parse_dir' of libmount/src/tab_parse.c:

	/* TODO: it would be nice to have a scandir() implementation that
	 *       is able to use already opened directory */

Nowadays glibc provides `scandirat'. This patch implements `scandirat'
based `mnt_table_parse_dir'.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/configure.ac b/configure.ac
index 1e2eb1be0943f6398e468da2d5194d28f2b8aab0..2792d74b5c87dda47b32af065b366d6f946fb329 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -263,6 +263,7 @@ AC_CHECK_FUNCS(
        lchown \
        llseek \
        lseek64 \
+       scandirat \
        strtoull \
        sysconf \
        getdtablesize \

diff --git a/libmount/src/tab_parse.c b/libmount/src/tab_parse.c
index 6cd66afeb369447b27ac1ed1e3c668337638ce9b..1b0324ef4a0270c0a23a1236092567b234665b28 100644 (file)
--- a/libmount/src/tab_parse.c
+++ b/libmount/src/tab_parse.c
@@ -5,6 +5,12 @@
  * GNU Lesser General Public License.
  */
 
+#ifdef HAVE_SCANDIRAT
+#ifndef __USE_GNU
+#define __USE_GNU
+#endif /* !__USE_GNU */
+#endif /* HAVE_SCANDIRAT */
+
 #include <ctype.h>
 #include <limits.h>
 #include <dirent.h>
@@ -429,14 +435,68 @@ int mnt_table_parse_file(struct libmnt_table *tb, const char *filename)
        return rc;
 }
 
+#ifdef HAVE_SCANDIRAT
+static int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
+{
+       int n = 0, i;
+       int dd;
+       struct dirent **namelist = NULL;
+
+       dd = open(dirname, O_RDONLY|O_CLOEXEC|O_DIRECTORY);
+       if (dd < 0)
+               return -errno;
+       n = scandirat(dd, ".", &namelist, NULL, versionsort);
+       if (n <= 0) {
+               close(dd);
+               return 0;
+       }
+
+       for (i = 0; i < n; i++) {
+               struct dirent *d = namelist[i];
+               struct stat st;
+               size_t namesz;
+               FILE *f;
+
+#ifdef _DIRENT_HAVE_D_TYPE
+               if (d->d_type != DT_UNKNOWN && d->d_type != DT_REG &&
+                   d->d_type != DT_LNK)
+                       continue;
+#endif
+               if (*d->d_name == '.')
+                       continue;
+
+#define MNT_MNTTABDIR_EXTSIZ   (sizeof(MNT_MNTTABDIR_EXT) - 1)
+
+               namesz = strlen(d->d_name);
+               if (!namesz || namesz < MNT_MNTTABDIR_EXTSIZ + 1 ||
+                   strcmp(d->d_name + (namesz - MNT_MNTTABDIR_EXTSIZ),
+                           MNT_MNTTABDIR_EXT))
+                               continue;
+
+               if (fstat_at(dd, ".", d->d_name, &st, 0) ||
+                   !S_ISREG(st.st_mode))
+                       continue;
+
+               f = fopen_at(dd, ".", d->d_name, O_RDONLY, "r");
+               if (f) {
+                       mnt_table_parse_stream(tb, f, d->d_name);
+                       fclose(f);
+               }
+       }
+
+       for (i = 0; i < n; i++)
+               free(namelist[i]);
+       free(namelist);
+       close(dd);
+       return 0;
+}
+#else
 static int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
 {
        int n = 0, i;
        DIR *dir = NULL;
        struct dirent **namelist = NULL;
 
-       /* TODO: it would be nice to have a scandir() implementation that
-        *       is able to use already opened directory */
        n = scandir(dirname, &namelist, NULL, versionsort);
        if (n <= 0)
                return 0;
@@ -487,6 +547,7 @@ static int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
                closedir(dir);
        return 0;
 }
+#endif
 
 struct libmnt_table *__mnt_new_table_from_file(const char *filename, int fmt)
 {