Use 'overlay' as fs name when needed

Close #389

We will probably also want to switch the order of the mount attempts, as
the new overlay fs should quickly become the more common scenario.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: KATOH Yasufumi <karma@jazz.email.ne.jp>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
This commit is contained in:
Serge Hallyn 2015-01-26 05:58:50 +00:00 committed by Stéphane Graber
parent ab35147cde
commit 38b34913fa

View File

@ -2138,6 +2138,28 @@ static int overlayfs_detect(const char *path)
return 0;
}
static char *overlayfs_name;
static char *detect_overlayfs_name(void)
{
char *v = "overlayfs";
char *line = NULL;
size_t len = 0;
FILE *f = fopen("/proc/filesystems", "r");
if (!f)
return v;
while (getline(&line, &len, f) != -1) {
if (strcmp(line, "nodev\toverlay\n") == 0) {
v = "overlay";
break;
}
}
fclose(f);
free(line);
return v;
}
//
// XXXXXXX plain directory bind mount ops
//
@ -2156,6 +2178,9 @@ static int overlayfs_mount(struct bdev *bdev)
if (!bdev->src || !bdev->dest)
return -22;
if (!overlayfs_name)
overlayfs_name = detect_overlayfs_name();
// separately mount it first
// mount -t overlayfs -oupperdir=${upper},lowerdir=${lower} lower dest
dup = alloca(strlen(bdev->src)+1);
@ -2216,13 +2241,13 @@ static int overlayfs_mount(struct bdev *bdev)
}
// mount without workdir option for overlayfs before v21
ret = mount(lower, bdev->dest, "overlayfs", MS_MGC_VAL | mntflags, options);
ret = mount(lower, bdev->dest, overlayfs_name, MS_MGC_VAL | mntflags, options);
if (ret < 0) {
INFO("overlayfs: error mounting %s onto %s options %s. retry with workdir",
lower, bdev->dest, options);
// retry with workdir option for overlayfs v22 and higher
ret = mount(lower, bdev->dest, "overlayfs", MS_MGC_VAL | mntflags, options_work);
ret = mount(lower, bdev->dest, overlayfs_name, MS_MGC_VAL | mntflags, options_work);
if (ret < 0)
SYSERROR("overlayfs: error mounting %s onto %s options %s",
lower, bdev->dest, options_work);