[PATCH 1/2] btrfs-progs: Move resize into functionaly into utils.c

[Marcos Paulo de Souza <marcos@mpdesouza.com>]

From: Marcos Paulo de Souza <mpdesouza@suse.com>

This function will be used in the next patch to auto resize the
filesystem when a bigger disk is added.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
---
 cmds/filesystem.c | 58 ++-------------------------------------------
 common/utils.c    | 60 +++++++++++++++++++++++++++++++++++++++++++++++
 common/utils.h    |  1 +
 3 files changed, 63 insertions(+), 56 deletions(-)

diff --git a/cmds/filesystem.c b/cmds/filesystem.c
index 4f22089a..9d31f236 100644
--- a/cmds/filesystem.c
+++ b/cmds/filesystem.c
@@ -1074,11 +1074,7 @@ static const char * const cmd_filesystem_resize_usage[] = {
 static int cmd_filesystem_resize(const struct cmd_struct *cmd,
 				 int argc, char **argv)
 {
-	struct btrfs_ioctl_vol_args	args;
-	int	fd, res, len, e;
-	char	*amount, *path;
-	DIR	*dirstream = NULL;
-	struct stat st;
+	char *amount, *path;
 
 	clean_args_no_options_relaxed(cmd, argc, argv);
 
@@ -1088,57 +1084,7 @@ static int cmd_filesystem_resize(const struct cmd_struct *cmd,
 	amount = argv[optind];
 	path = argv[optind + 1];
 
-	len = strlen(amount);
-	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
-		error("resize value too long (%s)", amount);
-		return 1;
-	}
-
-	res = stat(path, &st);
-	if (res < 0) {
-		error("resize: cannot stat %s: %m", path);
-		return 1;
-	}
-	if (!S_ISDIR(st.st_mode)) {
-		error("resize works on mounted filesystems and accepts only\n"
-			"directories as argument. Passing file containing a btrfs image\n"
-			"would resize the underlying filesystem instead of the image.\n");
-		return 1;
-	}
-
-	fd = btrfs_open_dir(path, &dirstream, 1);
-	if (fd < 0)
-		return 1;
-
-	printf("Resize '%s' of '%s'\n", path, amount);
-	memset(&args, 0, sizeof(args));
-	strncpy_null(args.name, amount);
-	res = ioctl(fd, BTRFS_IOC_RESIZE, &args);
-	e = errno;
-	close_file_or_dir(fd, dirstream);
-	if( res < 0 ){
-		switch (e) {
-		case EFBIG:
-			error("unable to resize '%s': no enough free space",
-				path);
-			break;
-		default:
-			error("unable to resize '%s': %m", path);
-			break;
-		}
-		return 1;
-	} else if (res > 0) {
-		const char *err_str = btrfs_err_str(res);
-
-		if (err_str) {
-			error("resizing of '%s' failed: %s", path, err_str);
-		} else {
-			error("resizing of '%s' failed: unknown error %d",
-				path, res);
-		}
-		return 1;
-	}
-	return 0;
+	return resize_filesystem(amount, path);
 }
 static DEFINE_SIMPLE_COMMAND(filesystem_resize, "resize");
 
diff --git a/common/utils.c b/common/utils.c
index 4ce36836..dddf0a6f 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -461,6 +461,66 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mod
 	return snprintf(str, str_size, "%.2f%s", fraction, suffix[num_divs]);
 }
 
+int resize_filesystem(const char *amount, const char *path)
+{
+	struct btrfs_ioctl_vol_args	args;
+	int	fd, res, len, e;
+	DIR	*dirstream = NULL;
+	struct stat st;
+
+	len = strlen(amount);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		error("resize value too long (%s)", amount);
+		return 1;
+	}
+
+	res = stat(path, &st);
+	if (res < 0) {
+		error("resize: cannot stat %s: %m", path);
+		return 1;
+	}
+	if (!S_ISDIR(st.st_mode)) {
+		error("resize works on mounted filesystems and accepts only\n"
+			"directories as argument. Passing file containing a btrfs image\n"
+			"would resize the underlying filesystem instead of the image.\n");
+		return 1;
+	}
+
+	fd = btrfs_open_dir(path, &dirstream, 1);
+	if (fd < 0)
+		return 1;
+
+	printf("Resize '%s' of '%s'\n", path, amount);
+	memset(&args, 0, sizeof(args));
+	strncpy_null(args.name, amount);
+	res = ioctl(fd, BTRFS_IOC_RESIZE, &args);
+	e = errno;
+	close_file_or_dir(fd, dirstream);
+	if( res < 0 ){
+		switch (e) {
+		case EFBIG:
+			error("unable to resize '%s': no enough free space",
+				path);
+			break;
+		default:
+			error("unable to resize '%s': %m", path);
+			break;
+		}
+		return 1;
+	} else if (res > 0) {
+		const char *err_str = btrfs_err_str(res);
+
+		if (err_str) {
+			error("resizing of '%s' failed: %s", path, err_str);
+		} else {
+			error("resizing of '%s' failed: unknown error %d",
+				path, res);
+		}
+		return 1;
+	}
+	return 0;
+}
+
 /*
  * Checks to make sure that the label matches our requirements.
  * Returns:
diff --git a/common/utils.h b/common/utils.h
index 5c1afda9..8609d3c9 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -62,6 +62,7 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
 		struct btrfs_fs_devices **fs_devices_mnt, unsigned sbflags);
 
 int pretty_size_snprintf(u64 size, char *str, size_t str_bytes, unsigned unit_mode);
+int resize_filesystem(const char *amount, const char *path);
 #define pretty_size(size) 	pretty_size_mode(size, UNITS_DEFAULT)
 const char *pretty_size_mode(u64 size, unsigned mode);
 
-- 
2.25.0