From 3f988c91763682afc1242de844a901837ab4863a Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu@suse.com>
Date: Wed, 10 Jan 2024 13:23:31 +1030
Subject: [PATCH] btrfs-progs: subvolume: fix return value when the target
 exists

[BUG]
When try to create a subvolume where the target path already exists, the
"btrfs" command doesn't return error code correctly.

  # mkfs.btrfs -f $dev
  # mount $dev $mnt
  # touch $mnt/subv1
  # btrfs subvolume create $mnt/subv1
  ERROR: target path already exists: $mnt/subv1
  # echo $?
  0

[CAUSE]
The check on whether target exists is done by path_is_dir(), if it
returns 0 or 1, it means there is something in that path already.

But unfortunately commit 5aa959fb3440 ("btrfs-progs: subvolume create:
accept multiple arguments") only changed the out label, which would
directly return @ret, not updating the return value correctly.

[FIX]
Make sure all error out branch has their @ret manually updated.

Fixes: 5aa959fb3440 ("btrfs-progs: subvolume create: accept multiple arguments")
Issue: #730
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 cmds/subvolume.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/cmds/subvolume.c b/cmds/subvolume.c
index 57be9ea..b01d5c8 100644
--- a/cmds/subvolume.c
+++ b/cmds/subvolume.c
@@ -160,12 +160,14 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 	}
 	if (ret >= 0) {
 		error("target path already exists: %s", dst);
+		ret = -EEXIST;
 		goto out;
 	}
 
 	dupname = strdup(dst);
 	if (!dupname) {
 		error_msg(ERROR_MSG_MEMORY, "duplicating %s", dst);
+		ret = -ENOMEM;
 		goto out;
 	}
 	newname = basename(dupname);
@@ -173,18 +175,21 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 	dupdir = strdup(dst);
 	if (!dupdir) {
 		error_msg(ERROR_MSG_MEMORY, "duplicating %s", dst);
+		ret = -ENOMEM;
 		goto out;
 	}
 	dstdir = dirname(dupdir);
 
 	if (!test_issubvolname(newname)) {
 		error("invalid subvolume name: %s", newname);
+		ret = -EINVAL;
 		goto out;
 	}
 
 	len = strlen(newname);
 	if (len > BTRFS_VOL_NAME_MAX) {
 		error("subvolume name too long: %s", newname);
+		ret = -EINVAL;
 		goto out;
 	}
 
@@ -208,6 +213,8 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 					goto out;
 				}
 			} else if (ret <= 0) {
+				if (ret == 0)
+					ret = -EEXIST;
 				errno = ret ;
 				error("failed to check directory %s before creation: %m", p);
 				goto out;
@@ -218,8 +225,10 @@ static int create_one_subvolume(const char *dst, struct btrfs_qgroup_inherit *in
 	}
 
 	fddst = btrfs_open_dir(dstdir, &dirstream, 1);
-	if (fddst < 0)
+	if (fddst < 0) {
+		ret = fddst;
 		goto out;
+	}
 
 	pr_verbose(LOG_DEFAULT, "Create subvolume '%s/%s'\n", dstdir, newname);
 	if (inherit) {
-- 
2.33.0