[PATCH 1/4] btrfs-progs: Remove fprintf() in find_mount_root().

[PATCH 1/4] btrfs-progs: Remove fprintf() in find_mount_root().

[Qu Wenruo]

find_mount_root() function in utils.c should not print error string.
Caller should be responsible to print error string.

This patch will remove the only fprintf in find_mount_root() and modify
the caller a little to use strerror() to prompt users.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 cmds-receive.c | 4 ++--
 cmds-send.c    | 4 ++--
 utils.c        | 6 +-----
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/cmds-receive.c b/cmds-receive.c
index 48380a5..72afe2a 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -980,9 +980,9 @@ static int do_receive(struct btrfs_receive *r, const char *tomnt, int r_fd,
 
 	ret = find_mount_root(dest_dir_full_path, &r->root_path);
 	if (ret < 0) {
-		ret = -EINVAL;
 		fprintf(stderr, "ERROR: failed to determine mount point "
-			"for %s\n", dest_dir_full_path);
+			"for %s: %s\n", dest_dir_full_path, strerror(-ret));
+		ret = -EINVAL;
 		goto out;
 	}
 	r->mnt_fd = open(r->root_path, O_RDONLY | O_NOATIME);
diff --git a/cmds-send.c b/cmds-send.c
index 9a73b32..48c3df4 100644
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -356,9 +356,9 @@ static int init_root_path(struct btrfs_send *s, const char *subvol)
 
 	ret = find_mount_root(subvol, &s->root_path);
 	if (ret < 0) {
-		ret = -EINVAL;
 		fprintf(stderr, "ERROR: failed to determine mount point "
-				"for %s\n", subvol);
+				"for %s: %s\n", subvol, strerror(-ret));
+		ret = -EINVAL;
 		goto out;
 	}
 
diff --git a/utils.c b/utils.c
index 11250d9..2d0f18e 100644
--- a/utils.c
+++ b/utils.c
@@ -2422,12 +2422,8 @@ int find_mount_root(const char *path, char **mount_root)
 	}
 	endmntent(mnttab);
 
-	if (!longest_match) {
-		fprintf(stderr,
-			"ERROR: Failed to find mount root for path %s.\n",
-			path);
+	if (!longest_match)
 		return -ENOENT;
-	}
 
 	ret = 0;
 	*mount_root = realpath(longest_match, NULL);
-- 
2.0.2

[PATCH v2 2/4] btrfs-progs: Check fstype in find_mount_root()

[Qu Wenruo]

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>
---
changelog:
v2:
   move error message to caller.
---
 cmds-receive.c   |  7 +++++++
 cmds-send.c      | 14 ++++++++++++++
 cmds-subvolume.c |  7 +++++++
 utils.c          |  9 +++++++++
 4 files changed, 37 insertions(+)

diff --git a/cmds-receive.c b/cmds-receive.c
index 72afe2a..0644b59 100644
--- a/cmds-receive.c
+++ b/cmds-receive.c
@@ -985,6 +985,13 @@ 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 48c3df4..d6b1855 100644
--- a/cmds-send.c
+++ b/cmds-send.c
@@ -361,6 +361,13 @@ 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) {
@@ -628,6 +635,13 @@ 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 639fb10..64a66e3 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -986,6 +986,13 @@ 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 2d0f18e..b96d5b4 100644
--- a/utils.c
+++ b/utils.c
@@ -2390,6 +2390,9 @@ int lookup_ino_rootid(int fd, u64 *rootid)
 	return 0;
 }
 
+/* return 0 if a btrfs mount point if 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;
@@ -2397,6 +2400,7 @@ int find_mount_root(const char *path, char **mount_root)
 	struct mntent *ent;
 	int len;
 	int ret;
+	int not_btrfs;
 	int longest_matchlen = 0;
 	char *longest_match = NULL;
 
@@ -2417,6 +2421,7 @@ 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");
 			}
 		}
 	}
@@ -2424,6 +2429,10 @@ 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);
-- 
2.0.2

[PATCH 3/4] btrfs-progs: Fix wrong indent in btrfs-progs.

[Qu Wenruo]

When editing cmds-filesystem.c, I found cmd_filesystem_df() uses 7
spaces as indent instead of 1 tab (or 8 spaces). which makes indent
quite embarrassing.
Such problem is especillay hard to detect when reviewing patches,
since the leading '+' makes a tab only 7 spaces long, makeing 7 spaces
look the same with a tab.

This patch fixes all the 7 spaces indent.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 cmds-filesystem.c | 79 +++++++++++++++++++++++++++----------------------------
 ctree.h           | 15 ++++++-----
 utils.c           | 10 +++----
 3 files changed, 52 insertions(+), 52 deletions(-)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index bf87bbe..108d9b7 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -114,23 +114,23 @@ static const char * const filesystem_cmd_group_usage[] = {
 };
 
 static const char * const cmd_filesystem_df_usage[] = {
-       "btrfs filesystem df <path>",
-       "Show space usage information for a mount point",
-       NULL
+	"btrfs filesystem df <path>",
+	"Show space usage information for a mount point",
+	NULL
 };
 
 static void print_df(struct btrfs_ioctl_space_args *sargs)
 {
-       u64 i;
-       struct btrfs_ioctl_space_info *sp = sargs->spaces;
-
-       for (i = 0; i < sargs->total_spaces; i++, sp++) {
-               printf("%s, %s: total=%s, used=%s\n",
-                       group_type_str(sp->flags),
-                       group_profile_str(sp->flags),
-                       pretty_size(sp->total_bytes),
-                       pretty_size(sp->used_bytes));
-       }
+	u64 i;
+	struct btrfs_ioctl_space_info *sp = sargs->spaces;
+
+	for (i = 0; i < sargs->total_spaces; i++, sp++) {
+		printf("%s, %s: total=%s, used=%s\n",
+		       group_type_str(sp->flags),
+		       group_profile_str(sp->flags),
+		       pretty_size(sp->total_bytes),
+		       pretty_size(sp->used_bytes));
+	}
 }
 
 static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
@@ -183,33 +183,32 @@ static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
 
 static int cmd_filesystem_df(int argc, char **argv)
 {
-       struct btrfs_ioctl_space_args *sargs = NULL;
-       int ret;
-       int fd;
-       char *path;
-       DIR *dirstream = NULL;
-
-       if (check_argc_exact(argc, 2))
-               usage(cmd_filesystem_df_usage);
-
-       path = argv[1];
-
-       fd = open_file_or_dir(path, &dirstream);
-       if (fd < 0) {
-               fprintf(stderr, "ERROR: can't access '%s'\n", path);
-               return 1;
-       }
-       ret = get_df(fd, &sargs);
-
-       if (!ret && sargs) {
-               print_df(sargs);
-               free(sargs);
-       } else {
-               fprintf(stderr, "ERROR: get_df failed %s\n", strerror(-ret));
-       }
-
-       close_file_or_dir(fd, dirstream);
-       return !!ret;
+	struct btrfs_ioctl_space_args *sargs = NULL;
+	int ret;
+	int fd;
+	char *path;
+	DIR *dirstream = NULL;
+
+	if (check_argc_exact(argc, 2))
+		usage(cmd_filesystem_df_usage);
+
+	path = argv[1];
+
+	fd = open_file_or_dir(path, &dirstream);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", path);
+		return 1;
+	}
+	ret = get_df(fd, &sargs);
+	if (!ret && sargs) {
+		print_df(sargs);
+		free(sargs);
+	} else {
+		fprintf(stderr, "ERROR: get_df failed %s\n", strerror(-ret));
+	}
+
+	close_file_or_dir(fd, dirstream);
+	return !!ret;
 }
 
 static int match_search_item_kernel(__u8 *fsid, char *mnt, char *label,
diff --git a/ctree.h b/ctree.h
index 35d3633..83d85b3 100644
--- a/ctree.h
+++ b/ctree.h
@@ -939,10 +939,10 @@ struct btrfs_block_group_cache {
 };
 
 struct btrfs_extent_ops {
-       int (*alloc_extent)(struct btrfs_root *root, u64 num_bytes,
-		           u64 hint_byte, struct btrfs_key *ins);
-       int (*free_extent)(struct btrfs_root *root, u64 bytenr,
-		          u64 num_bytes);
+	int (*alloc_extent)(struct btrfs_root *root, u64 num_bytes,
+			    u64 hint_byte, struct btrfs_key *ins);
+	int (*free_extent)(struct btrfs_root *root, u64 bytenr,
+			   u64 num_bytes);
 };
 
 struct btrfs_device;
@@ -2117,9 +2117,10 @@ BTRFS_SETGET_STACK_FUNCS(stack_qgroup_limit_rsv_exclusive,
 static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,
 						    struct btrfs_item *e)
 {
-       unsigned long offset;
-       offset = offsetof(struct btrfs_file_extent_item, disk_bytenr);
-       return btrfs_item_size(eb, e) - offset;
+	unsigned long offset;
+
+	offset = offsetof(struct btrfs_file_extent_item, disk_bytenr);
+	return btrfs_item_size(eb, e) - offset;
 }
 
 /* this returns the number of file bytes represented by the inline item.
diff --git a/utils.c b/utils.c
index b96d5b4..8befd57 100644
--- a/utils.c
+++ b/utils.c
@@ -1467,15 +1467,15 @@ char *__strncpy__null(char *dest, const char *src, size_t n)
  */
 static int check_label(const char *input)
 {
-       int len = strlen(input);
+	int len = strlen(input);
 
-       if (len > BTRFS_LABEL_SIZE - 1) {
+	if (len > BTRFS_LABEL_SIZE - 1) {
 		fprintf(stderr, "ERROR: Label %s is too long (max %d)\n",
 			input, BTRFS_LABEL_SIZE - 1);
-               return -1;
-       }
+		return -1;
+	}
 
-       return 0;
+	return 0;
 }
 
 static int set_label_unmounted(const char *dev, const char *label)
-- 
2.0.2

[PATCH v3 4/4] btrfs-progs: Add mount point output for 'btrfs fi df'

[Qu Wenruo]

Add mount point output for 'btrfs fi df'.
Also since the patch uses find_mount_root() to find mount point,
now 'btrfs fi df' can output more meaningful error message when given a
non-btrfs path.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
changelog:
v2:
  Call realpath() before find_mount_root() to deal with relative path
v3:
  Only output mount point when get_df() successed.
---

 cmds-filesystem.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 108d9b7..ca6bcad 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -187,6 +187,8 @@ static int cmd_filesystem_df(int argc, char **argv)
 	int ret;
 	int fd;
 	char *path;
+	char *real_path = NULL;
+	char *mount_point = NULL;
 	DIR *dirstream = NULL;
 
 	if (check_argc_exact(argc, 2))
@@ -194,6 +196,29 @@ static int cmd_filesystem_df(int argc, char **argv)
 
 	path = argv[1];
 
+	real_path = realpath(path, NULL);
+	if (!real_path) {
+		fprintf(stderr,
+			"ERROR: Failed to resolve real path for %s: %s\n",
+			path, strerror(errno));
+		return 1;
+	}
+	ret = find_mount_root(real_path, &mount_point);
+	if (ret < 0) {
+		fprintf(stderr,
+			"ERROR: failed to determine mount point for %s: %s\n",
+			path, strerror(-ret));
+		free(real_path);
+		return 1;
+	}
+	if (ret > 0) {
+		fprintf(stderr,
+			"ERROR: %s does not belong to a btrfs mount point\n",
+			path);
+		free(real_path);
+		return 1;
+	}
+
 	fd = open_file_or_dir(path, &dirstream);
 	if (fd < 0) {
 		fprintf(stderr, "ERROR: can't access '%s'\n", path);
@@ -201,12 +226,15 @@ static int cmd_filesystem_df(int argc, char **argv)
 	}
 	ret = get_df(fd, &sargs);
 	if (!ret && sargs) {
+		printf("Mounted on: %s\n", mount_point);
 		print_df(sargs);
 		free(sargs);
 	} else {
 		fprintf(stderr, "ERROR: get_df failed %s\n", strerror(-ret));
 	}
 
+	free(real_path);
+	free(mount_point);
 	close_file_or_dir(fd, dirstream);
 	return !!ret;
 }
-- 
2.0.2

Re: [PATCH v2 2/4] btrfs-progs: Check fstype in find_mount_root()

[David Sterba]

On Wed, Jul 23, 2014 at 01:47:35PM +0800, Qu Wenruo wrote:
> --- a/utils.c
> +++ b/utils.c
> @@ -2390,6 +2390,9 @@ int lookup_ino_rootid(int fd, u64 *rootid)
>  	return 0;
>  }
>  
> +/* return 0 if a btrfs mount point if 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;
> @@ -2397,6 +2400,7 @@ int find_mount_root(const char *path, char **mount_root)
>  	struct mntent *ent;
>  	int len;
>  	int ret;
> +	int not_btrfs;

    [CC]     utils.o
utils.c: In function ‘find_mount_root’:
utils.c:2342:6: warning: ‘not_btrfs’ may be used uninitialized in this function

I've initialized to 1 to fix it, no need to resend the patch.