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authorAlexander Shishkin <virtuoso@slind.org>2010-10-28 04:10:03 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-10-28 04:10:03 (GMT)
commit776509544123c68bbc128c0fdb2f699062d294cf (patch)
treebda6c568102334dca82da268b9aa42b012a4ed69
parent78b286fea51ef137d660b91037c89376115a1994 (diff)
downloadbusybox-776509544123c68bbc128c0fdb2f699062d294cf.tar.gz
busybox-776509544123c68bbc128c0fdb2f699062d294cf.tar.bz2
mount: pass NULL, not "", as "data" to mount syscall if we have no opts
When mounting a filesystem without any additional options (data parameter to the mount(2) syscall), pass NULL instead of an empty string like GNU mount does. This fixes, for example mounting cgroup fs with bbox mount. Signed-off-by: Alexander Shishkin <virtuoso@slind.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--util-linux/mount.c34
1 files changed, 22 insertions, 12 deletions
diff --git a/util-linux/mount.c b/util-linux/mount.c
index 3ac8ce0..0f213bb 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -332,7 +332,7 @@ static void append_mount_options(char **oldopts, const char *newopts)
}
// Use the mount_options list to parse options into flags.
-// Also return list of unrecognized options if unrecognized != NULL
+// Also update list of unrecognized options if unrecognized != NULL
static long parse_mount_options(char *options, char **unrecognized)
{
long flags = MS_SILENT;
@@ -348,25 +348,35 @@ static long parse_mount_options(char *options, char **unrecognized)
// FIXME: use hasmntopt()
// Find this option in mount_options
for (i = 0; i < ARRAY_SIZE(mount_options); i++) {
- if (!strcasecmp(option_str, options)) {
+ if (strcasecmp(option_str, options) == 0) {
long fl = mount_options[i];
- if (fl < 0) flags &= fl;
- else flags |= fl;
- break;
+ if (fl < 0)
+ flags &= fl;
+ else
+ flags |= fl;
+ goto found;
}
option_str += strlen(option_str) + 1;
}
- // If unrecognized not NULL, append unrecognized mount options
- if (unrecognized && i == ARRAY_SIZE(mount_options)) {
+ // We did not recognize this option.
+ // If "unrecognized" is not NULL, append option there.
+ // Note that we should not append *empty* option -
+ // in this case we want to pass NULL, not "", to "data"
+ // parameter of mount(2) syscall.
+ // This is crucial for filesystems that don't accept
+ // any arbitrary mount options, like cgroup fs:
+ // "mount -t cgroup none /mnt"
+ if (options[0] && unrecognized) {
// Add it to strflags, to pass on to kernel
- i = *unrecognized ? strlen(*unrecognized) : 0;
- *unrecognized = xrealloc(*unrecognized, i + strlen(options) + 2);
+ char *p = *unrecognized;
+ unsigned len = p ? strlen(p) : 0;
+ *unrecognized = p = xrealloc(p, len + strlen(options) + 2);
// Comma separated if it's not the first one
- if (i) (*unrecognized)[i++] = ',';
- strcpy((*unrecognized)+i, options);
+ if (len) p[len++] = ',';
+ strcpy(p + len, options);
}
-
+ found:
if (!comma)
break;
// Advance to next option