X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=409ccc7eed7df5fa61cd7b2d51b40d756665cd52;hb=a7e07206021c6484a8d33c6ee156ecfb5b90534c;hp=390ad1d83a26c18fb14f82bf77ef168c86ae3222;hpb=9bc5cd6d74d6efc7769d6a25b21e451dae39fe76;p=elogind.git

diff --git a/src/shared/util.c b/src/shared/util.c
index 390ad1d83..409ccc7ee 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -61,6 +61,7 @@
 #include <sys/personality.h>
 #include <sys/xattr.h>
 #include <libgen.h>
+#include <sys/statvfs.h>
 #undef basename
 
 #ifdef HAVE_SYS_AUXV_H
@@ -6858,6 +6859,15 @@ int umount_recursive(const char *prefix, int flags) {
         return r ? r : n;
 }
 
+static int get_mount_flags(const char *path, unsigned long *flags) {
+        struct statvfs buf;
+
+        if (statvfs(path, &buf) < 0)
+                return -errno;
+        *flags = buf.f_flag;
+        return 0;
+}
+
 int bind_remount_recursive(const char *prefix, bool ro) {
         _cleanup_set_free_free_ Set *done = NULL;
         _cleanup_free_ char *cleaned = NULL;
@@ -6892,6 +6902,7 @@ int bind_remount_recursive(const char *prefix, bool ro) {
                 _cleanup_set_free_free_ Set *todo = NULL;
                 bool top_autofs = false;
                 char *x;
+                unsigned long orig_flags;
 
                 todo = set_new(&string_hash_ops);
                 if (!todo)
@@ -6969,7 +6980,11 @@ int bind_remount_recursive(const char *prefix, bool ro) {
                         if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0)
                                 return -errno;
 
-                        if (mount(NULL, prefix, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
+                        orig_flags = 0;
+                        (void) get_mount_flags(cleaned, &orig_flags);
+                        orig_flags &= ~MS_RDONLY;
+
+                        if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0)
                                 return -errno;
 
                         x = strdup(cleaned);
@@ -6989,7 +7004,14 @@ int bind_remount_recursive(const char *prefix, bool ro) {
                         if (r < 0)
                                 return r;
 
-                        if (mount(NULL, x, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) {
+                        /* Try to reuse the original flag set, but
+                         * don't care for errors, in case of
+                         * obstructed mounts */
+                        orig_flags = 0;
+                        (void) get_mount_flags(x, &orig_flags);
+                        orig_flags &= ~MS_RDONLY;
+
+                        if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) {
 
                                 /* Deal with mount points that are
                                  * obstructed by a later mount */
@@ -7653,3 +7675,28 @@ int fd_setcrtime(int fd, usec_t usec) {
 
         return 0;
 }
+
+int same_fd(int a, int b) {
+        struct stat sta, stb;
+
+        assert(a >= 0);
+        assert(b >= 0);
+
+        if (a == b)
+                return true;
+
+        if (fstat(a, &sta) < 0)
+                return -errno;
+
+        if (fstat(b, &stb) < 0)
+                return -errno;
+
+        if ((sta.st_mode & S_IFMT) != (stb.st_mode & S_IFMT))
+                return false;
+
+        if (S_ISREG(sta.st_mode) || S_ISDIR(sta.st_mode) || S_ISFIFO(sta.st_mode) || S_ISSOCK(sta.st_mode) || S_ISLNK(sta.st_mode))
+                return (sta.st_dev == stb.st_dev) && (sta.st_ino == stb.st_ino);
+
+        /* We consider all device fds different... */
+        return false;
+}