Two fixes:
1)
Check that the parent subvol actually is reachable via our root path.
The previous code wouldn't catch
parent subvol: foo/bar
root path: bar (i.e. mounted with -o subvol=bar)
where the parent isn't reachable from the root path.
(but the original "strstr(parent, root_path) == NULL" check still doesn't hold)
Also check for the slash after "root_path", i.e. throw an error on
parent subvol: foobar
root path: foo
2)
If the parent subvol is the one that is mounted we obviously can't
receive into it, as it has to be read-only by definition.
We'd get a rather cryptic:
At subvol /tmp/test/dest.snap
At snapshot dest.snap
ERROR: creating snapshot / -> dest.snap failed: Invalid cross-device link
(not sure what it says if "/" isn't even a btrfs)
But with this we get
At subvol /tmp/test/dest.snap
At snapshot dest.snap
ERROR: creating snapshot . -> dest.snap failed: Read-only file system
which is both more helpful and more correct.
Signed-off-by: Benedikt Morbach <benedikt.morbach@xxxxxxxxxxxxxx>
---
cmds-receive.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/cmds-receive.c b/cmds-receive.c
index 166d37d..790218c 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -314,8 +314,8 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
sub_len = strlen(parent_subvol->path);
/* First make sure the parent subvol is actually in our path */
- if (sub_len < root_len ||
- strstr(parent_subvol->path, rctx->full_root_path) == NULL) {
+ if (strstr(parent_subvol->path, rctx->full_root_path) != parent_subvol->path ||
+ sub_len > root_len && parent_subvol->path[root_len] != '/') {
error(
"parent subvol is not reachable from inside the root subvol");
ret = -ENOENT;
@@ -323,7 +323,7 @@ static int process_snapshot(const char *path, const u8 *uuid, u64 ctransid,
}
if (sub_len == root_len) {
- parent_subvol->path[0] = '/';
+ parent_subvol->path[0] = '.';
parent_subvol->path[1] = '\0';
} else {
/*
--
2.11.1
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
