From de22c28ef31d9721606ba05965a093a8044be0de Mon Sep 17 00:00:00 2001
From: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date: Wed, 23 Jul 2014 13:47:35 +0800
Subject: [PATCH] btrfs-progs: Check fstype in find_mount_root()

When calling find_mount_root(), caller in fact wants to find the mount
point of *BTRFS*.

So also check ent->fstype in find_mount_root() and do special error
string output in caller.

This will suppress a lot of "Inapproiate ioctl for device" error
message.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
---
 cmds-receive.c   |  7 +++++++
 cmds-send.c      | 14 ++++++++++++++
 cmds-subvolume.c |  7 +++++++
 utils.c          | 11 +++++++++++
 4 files changed, 39 insertions(+)

diff --git a/cmds-receive.c b/cmds-receive.c
index 20b3db09..03d21e90 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -848,6 +848,13 @@ static int do_receive(struct btrfs_receive *r, const char *tomnt, int r_fd,
 		ret = -EINVAL;
 		goto out;
 	}
+	if (ret > 0) {
+		fprintf(stderr,
+			"ERROR: %s doesn't belong to btrfs mount point\n",
+			dest_dir_full_path);
+		ret = -EINVAL;
+		goto out;
+	}
 	r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
 	if (r->mnt_fd < 0) {
 		ret = -errno;
diff --git a/cmds-send.c b/cmds-send.c
index 9ec52dcd..7141c073 100644
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -355,6 +355,13 @@ static int init_root_path(struct btrfs_send *s, const char *subvol)
 		ret = -EINVAL;
 		goto out;
 	}
+	if (ret > 0) {
+		fprintf(stderr,
+			"ERROR: %s doesn't belong to btrfs mount point\n",
+			subvol);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	s->mnt_fd = open(s->root_path, O_RDONLY | O_NOATIME);
 	if (s->mnt_fd < 0) {
@@ -587,6 +594,13 @@ int cmd_send(int argc, char **argv)
 				strerror(-ret));
 			goto out;
 		}
+		if (ret > 0) {
+			fprintf(stderr,
+			"ERROR: %s doesn't belong to btrfs mount point\n",
+				subvol);
+			ret = -EINVAL;
+			goto out;
+		}
 		if (strcmp(send.root_path, mount_root) != 0) {
 			ret = -EINVAL;
 			fprintf(stderr, "ERROR: all subvols must be from the "
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 5e821c71..9ab5287b 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -933,6 +933,13 @@ static int cmd_subvol_show(int argc, char **argv)
 				"%s\n", fullpath, strerror(-ret));
 		goto out;
 	}
+	if (ret > 0) {
+		fprintf(stderr,
+			"ERROR: %s doesn't belong to btrfs mount point\n",
+			fullpath);
+		ret = -EINVAL;
+		goto out;
+	}
 	ret = 1;
 	svpath = get_subvol_name(mnt, fullpath);
 
diff --git a/utils.c b/utils.c
index 3d467c56..73fcd15f 100644
--- a/utils.c
+++ b/utils.c
@@ -2324,6 +2324,11 @@ int lookup_ino_rootid(int fd, u64 *rootid)
 	return 0;
 }
 
+/*
+ * return 0 if a btrfs mount point is found
+ * return 1 if a mount point is found but not btrfs
+ * return <0 if something goes wrong
+ */
 int find_mount_root(const char *path, char **mount_root)
 {
 	FILE *mnttab;
@@ -2331,6 +2336,7 @@ int find_mount_root(const char *path, char **mount_root)
 	struct mntent *ent;
 	int len;
 	int ret;
+	int not_btrfs = 1;
 	int longest_matchlen = 0;
 	char *longest_match = NULL;
 
@@ -2351,6 +2357,7 @@ int find_mount_root(const char *path, char **mount_root)
 				free(longest_match);
 				longest_matchlen = len;
 				longest_match = strdup(ent->mnt_dir);
+				not_btrfs = strcmp(ent->mnt_type, "btrfs");
 			}
 		}
 	}
@@ -2358,6 +2365,10 @@ int find_mount_root(const char *path, char **mount_root)
 
 	if (!longest_match)
 		return -ENOENT;
+	if (not_btrfs) {
+		free(longest_match);
+		return 1;
+	}
 
 	ret = 0;
 	*mount_root = realpath(longest_match, NULL);