new util: 'btrfs'

This commit introduces a new command called 'btrfs' for managing
a btrfs filesystem. 'btrfs' handles:
- snapshot/subvolume creation
- adding/removal of volume (ie: disk)
- defragment of a tree
- scan of a device searching a btrfs filesystem
- re-balancing of the chunk on the disks
- listing subvolumes and snapshots

This has also been updated to include the new defrag range ioctl.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 788 insertions, 0 deletions

diff --git a/btrfs_cmds.c b/btrfs_cmds.c
new file mode 100644
index 00000000..3a21be31
--- /dev/null
+++ b/btrfs_cmds.c
@@ -0,0 +1,788 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <limits.h>
+#include <uuid/uuid.h>
+#include <ctype.h>
+
+#undef ULONG_MAX
+
+#include "kerncompat.h"
+#include "ctree.h"
+#include "transaction.h"
+#include "utils.h"
+#include "version.h"
+#include "ioctl.h"
+#include "volumes.h"
+
+#include "btrfs_cmds.h"
+
+#ifdef __CHECKER__
+#define BLKGETSIZE64 0
+#define BTRFS_IOC_SNAP_CREATE 0
+#define BTRFS_VOL_NAME_MAX 255
+struct btrfs_ioctl_vol_args { char name[BTRFS_VOL_NAME_MAX]; };
+static inline int ioctl(int fd, int define, void *arg) { return 0; }
+#endif
+
+/*
+ * test if path is a subvolume:
+ * this function return
+ * 0-> path exists but it is not a subvolume
+ * 1-> path exists and it is  a subvolume
+ * -1 -> path is unaccessible
+ */
+static int test_issubvolume(char *path)
+{
+
+	struct stat	st;
+	int		res;
+
+	res = stat(path, &st);
+	if(res < 0 )
+		return -1;
+
+	return (st.st_ino == 256) && S_ISDIR(st.st_mode);
+
+}
+
+/*
+ * test if path is a directory
+ * this function return
+ * 0-> path exists but it is not a directory
+ * 1-> path exists and it is  a directory
+ * -1 -> path is unaccessible
+ */
+static int test_isdir(char *path)
+{
+	struct stat	st;
+	int		res;
+
+	res = stat(path, &st);
+	if(res < 0 )
+		return -1;
+
+	return S_ISDIR(st.st_mode);
+
+}
+
+static int open_file_or_dir(const char *fname)
+{
+	int ret;
+	struct stat st;
+	DIR *dirstream;
+	int fd;
+
+	ret = stat(fname, &st);
+	if (ret < 0) {
+		return -1;
+	}
+	if (S_ISDIR(st.st_mode)) {
+		dirstream = opendir(fname);
+		if (!dirstream) {
+			return -2;
+		}
+		fd = dirfd(dirstream);
+	} else {
+		fd = open(fname, O_RDWR);
+	}
+	if (fd < 0) {
+		return -3;
+	}
+	return fd;
+}
+
+static u64 parse_size(char *s)
+{
+	int len = strlen(s);
+	char c;
+	u64 mult = 1;
+
+	if (!isdigit(s[len - 1])) {
+		c = tolower(s[len - 1]);
+		switch (c) {
+		case 'g':
+			mult *= 1024;
+		case 'm':
+			mult *= 1024;
+		case 'k':
+			mult *= 1024;
+		case 'b':
+			break;
+		default:
+			fprintf(stderr, "Unknown size descriptor %c\n", c);
+			exit(1);
+		}
+		s[len - 1] = '\0';
+	}
+	return atoll(s) * mult;
+}
+
+int do_defrag(int ac, char **avp)
+{
+	int fd;
+	int compress = 0;
+	int flush = 0;
+	u64 start = 0;
+	u64 len = (u64)-1;
+	u32 thresh = 0;
+	int i;
+	int errors = 0;
+	int ret = 0;
+	int verbose = 0;
+	int fancy_ioctl = 0;
+	struct btrfs_ioctl_defrag_range_args range;
+	char **av;
+
+	/*
+	 * getopt expects av[0] to be the program name and it seems
+	 * to get confused when this isn't the case
+	 */
+	av = malloc((ac + 2) * sizeof(char *));
+	av[0] = "defrag";
+	av[ac + 1] = NULL;
+	memcpy(av + 1, avp, ac * sizeof(char *));
+	ac += 1;
+
+	optind = 1;
+	while(1) {
+		int c = getopt(ac, av, "vcfs:l:t:");
+		if (c < 0)
+			break;
+		switch(c) {
+		case 'c':
+			compress = 1;
+			fancy_ioctl = 1;
+			break;
+		case 'f':
+			flush = 1;
+			fancy_ioctl = 1;
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		case 's':
+			start = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		case 'l':
+			len = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		case 't':
+			thresh = parse_size(optarg);
+			fancy_ioctl = 1;
+			break;
+		default:
+			fprintf(stderr, "Invalid arguments for defragment\n");
+			free(av);
+			return 1;
+		}
+	}
+	if (ac - optind == 0) {
+		fprintf(stderr, "Invalid arguments for defragment\n");
+		free(av);
+		return 1;
+	}
+
+	memset(&range, 0, sizeof(range));
+	range.start = start;
+	range.len = len;
+	range.extent_thresh = thresh;
+	if (compress)
+		range.flags |= BTRFS_DEFRAG_RANGE_COMPRESS;
+	if (flush)
+		range.flags |= BTRFS_DEFRAG_RANGE_START_IO;
+
+	for (i = optind; i < ac; i++) {
+		if (verbose)
+			printf("%s\n", av[i]);
+		fd = open_file_or_dir(av[i]);
+		if (fd < 0) {
+			fprintf(stderr, "failed to open %s\n", av[i]);
+			perror("open:");
+			errors++;
+			continue;
+		}
+		if (!fancy_ioctl) {
+			ret = ioctl(fd, BTRFS_IOC_DEFRAG, NULL);
+		} else {
+			ret = ioctl(fd, BTRFS_IOC_DEFRAG_RANGE, &range);
+			if (ret && errno == ENOTTY) {
+				fprintf(stderr, "defrag range ioctl not "
+					"supported in this kernel, please try "
+					"without any options.\n");
+				errors++;
+				break;
+			}
+		}
+		if (ret) {
+			fprintf(stderr, "ioctl failed on %s ret %d errno %d\n",
+				av[i], ret, errno);
+			errors++;
+		}
+		close(fd);
+	}
+	if (verbose)
+		printf("%s\n", BTRFS_BUILD_VERSION);
+	if (errors) {
+		fprintf(stderr, "total %d failures\n", errors);
+		exit(1);
+	}
+
+	free(av);
+	return errors + 20;
+}
+
+int do_subvol_list(int argc, char **argv)
+{
+	int fd;
+	int ret;
+	char *subvol;
+
+	subvol = argv[0];
+
+	ret = test_issubvolume(subvol);
+	if (ret < 0) {
+		fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
+		return 12;
+	}
+	if (!ret) {
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
+		return 13;
+	}
+
+	fd = open_file_or_dir(subvol);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
+		return 12;
+	}
+	ret = list_subvols(fd);
+	if (ret)
+		return 19;
+	return 0;
+}
+
+int do_clone(int argc, char **argv)
+{
+	char	*subvol, *dst;
+	int	res, fd, fddst, len;
+	char	*newname;
+	char	*dstdir;
+
+	subvol = argv[0];
+	dst = argv[1];
+	struct btrfs_ioctl_vol_args	args;
+
+	res = test_issubvolume(subvol);
+	if(res<0){
+		fprintf(stderr, "ERROR: error accessing '%s'\n", subvol);
+		return 12;
+	}
+	if(!res){
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", subvol);
+		return 13;
+	}
+
+	res = test_isdir(dst);
+	if(res == 0 ){
+		fprintf(stderr, "ERROR: '%s' exists and it is not a directory\n", dst);
+		return 12;
+	}
+
+	if(res>0){
+		newname = strdup(subvol);
+		newname = basename(newname);
+		dstdir = dst;
+	}else{
+		newname = strdup(dst);
+		newname = basename(newname);
+		dstdir = strdup(dst);
+		dstdir = dirname(dstdir);
+	}
+
+	if( !strcmp(newname,".") || !strcmp(newname,"..") ||
+	     strchr(newname, '/') ){
+		fprintf(stderr, "ERROR: incorrect snapshot name ('%s')\n",
+			newname);
+		return 14;
+	}
+
+	len = strlen(newname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
+			newname);
+		return 14;
+	}
+
+	fddst = open_file_or_dir(dstdir);
+	if (fddst < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	fd = open_file_or_dir(subvol);
+	if (fd < 0) {
+		close(fddst);
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	printf("Create a snapshot of '%s' in '%s/%s'\n",
+	       subvol, dstdir, newname);
+	args.fd = fd;
+	strcpy(args.name, newname);
+	res = ioctl(fddst, BTRFS_IOC_SNAP_CREATE, &args);
+
+	close(fd);
+	close(fddst);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot snapshot '%s'\n",subvol);
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_delete_subvolume(int argc, char **argv)
+{
+	int	res, fd, len;
+	struct btrfs_ioctl_vol_args	args;
+	char	*dname, *vname, *cpath;
+	char	*path = argv[0];
+
+	res = test_issubvolume(path);
+	if(res<0){
+		fprintf(stderr, "ERROR: error accessing '%s'\n", path);
+		return 12;
+	}
+	if(!res){
+		fprintf(stderr, "ERROR: '%s' is not a subvolume\n", path);
+		return 13;
+	}
+
+	cpath = realpath(path, 0);
+	dname = strdup(cpath);
+	dname = dirname(dname);
+	vname = strdup(cpath);
+	vname = basename(vname);
+	free(cpath);
+
+	if( !strcmp(vname,".") || !strcmp(vname,"..") ||
+	     strchr(vname, '/') ){
+		fprintf(stderr, "ERROR: incorrect subvolume name ('%s')\n",
+			vname);
+		return 14;
+	}
+
+	len = strlen(vname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: snapshot name too long ('%s)\n",
+			vname);
+		return 14;
+	}
+
+	fd = open_file_or_dir(dname);
+	if (fd < 0) {
+		close(fd);
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dname);
+		return 12;
+	}
+
+	printf("Delete subvolume '%s/%s'\n", dname, vname);
+	strcpy(args.name, vname);
+	res = ioctl(fd, BTRFS_IOC_SNAP_DESTROY, &args);
+
+	close(fd);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot delete '%s/%s'\n",dname, vname);
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_create_subvol(int argc, char **argv)
+{
+	int	res, fddst, len;
+	char	*newname;
+	char	*dstdir;
+	struct btrfs_ioctl_vol_args	args;
+	char	*dst = argv[0];
+
+	res = test_isdir(dst);
+	if(res >= 0 ){
+		fprintf(stderr, "ERROR: '%s' exists\n", dst);
+		return 12;
+	}
+
+	newname = strdup(dst);
+	newname = basename(newname);
+	dstdir = strdup(dst);
+	dstdir = dirname(dstdir);
+
+	if( !strcmp(newname,".") || !strcmp(newname,"..") ||
+	     strchr(newname, '/') ){
+		fprintf(stderr, "ERROR: uncorrect subvolume name ('%s')\n",
+			newname);
+		return 14;
+	}
+
+	len = strlen(newname);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: subvolume name too long ('%s)\n",
+			newname);
+		return 14;
+	}
+
+	fddst = open_file_or_dir(dstdir);
+	if (fddst < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", dstdir);
+		return 12;
+	}
+
+	printf("Create subvolume '%s/%s'\n", dstdir, newname);
+	strcpy(args.name, newname);
+	res = ioctl(fddst, BTRFS_IOC_SUBVOL_CREATE, &args);
+
+	close(fddst);
+
+	if(res < 0 ){
+		fprintf( stderr, "ERROR: cannot create subvolume\n");
+		return 11;
+	}
+
+	return 0;
+
+}
+
+int do_fssync(int argc, char **argv)
+{
+	int fd, res;
+	char	*path = argv[0];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	printf("FSSync '%s'\n", path);
+	res = ioctl(fd, BTRFS_IOC_SYNC);
+	close(fd);
+	if( res < 0 ){
+		fprintf(stderr, "ERROR: unable to fs-syncing '%s'\n", path);
+		return 16;
+	}
+
+	return 0;
+}
+
+int do_scan(int nargs, char **argv)
+{
+	int	i, fd;
+	if(!nargs){
+		int ret;
+
+		printf("Scanning for Btrfs filesystems\n");
+		ret = btrfs_scan_one_dir("/dev", 1);
+		if (ret){
+			fprintf(stderr, "ERROR: error %d while scanning\n", ret);
+			return 18;
+		}
+		return 0;
+	}
+
+	fd = open("/dev/btrfs-control", O_RDWR);
+	if (fd < 0) {
+		perror("failed to open /dev/btrfs-control");
+		return 10;
+	}
+
+	for( i = 0 ; i < nargs ; i++ ){
+		struct btrfs_ioctl_vol_args	args;
+		int	ret;
+
+		printf("Scanning for Btrfs filesystems in '%s'\n", argv[i]);
+
+		strcpy(args.name, argv[i]);
+		/*
+		 * FIXME: which are the error code returned by this ioctl ?
+		 * it seems that is impossible to understand if there no is
+		 * a btrfs filesystem from an I/O error !!!
+		 */
+		ret = ioctl(fd, BTRFS_IOC_SCAN_DEV, &args);
+
+		if( ret < 0 ){
+			close(fd);
+			fprintf(stderr, "ERROR: unable to scan the device '%s'\n", argv[i]);
+			return 11;
+		}
+	}
+
+	close(fd);
+	return 0;
+
+}
+
+int do_resize(int argc, char **argv)
+{
+
+	struct btrfs_ioctl_vol_args	args;
+	int	fd, res, len;
+	char	*amount=argv[0], *path=argv[1];
+
+	fd = open_file_or_dir(path);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+	len = strlen(amount);
+	if (len == 0 || len >= BTRFS_VOL_NAME_MAX) {
+		fprintf(stderr, "ERROR: size value too long ('%s)\n",
+			amount);
+		return 14;
+	}
+
+	printf("Resize '%s' of '%s'\n", path, amount);
+	strcpy(args.name, amount);
+	res = ioctl(fd, BTRFS_IOC_RESIZE, &args);
+	close(fd);
+	if( res < 0 ){
+		fprintf(stderr, "ERROR: unable to resize '%s'\n", path);
+		return 30;
+	}
+	return 0;
+}
+
+static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
+{
+	struct list_head *cur;
+	struct btrfs_device *device;
+
+	list_for_each(cur, &fs_devices->devices) {
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		if ((device->label && strcmp(device->label, search) == 0) ||
+		    strcmp(device->name, search) == 0)
+			return 1;
+	}
+	return 0;
+}
+
+static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
+{
+	char uuidbuf[37];
+	struct list_head *cur;
+	struct btrfs_device *device;
+	char *super_bytes_used;
+	u64 devs_found = 0;
+	u64 total;
+
+	uuid_unparse(fs_devices->fsid, uuidbuf);
+	device = list_entry(fs_devices->devices.next, struct btrfs_device,
+			    dev_list);
+	if (device->label && device->label[0])
+		printf("Label: '%s' ", device->label);
+	else
+		printf("Label: none ");
+
+	super_bytes_used = pretty_sizes(device->super_bytes_used);
+
+	total = device->total_devs;
+	printf(" uuid: %s\n\tTotal devices %llu FS bytes used %s\n", uuidbuf,
+	       (unsigned long long)total, super_bytes_used);
+
+	free(super_bytes_used);
+
+	list_for_each(cur, &fs_devices->devices) {
+		char *total_bytes;
+		char *bytes_used;
+		device = list_entry(cur, struct btrfs_device, dev_list);
+		total_bytes = pretty_sizes(device->total_bytes);
+		bytes_used = pretty_sizes(device->bytes_used);
+		printf("\tdevid %4llu size %s used %s path %s\n",
+		       (unsigned long long)device->devid,
+		       total_bytes, bytes_used, device->name);
+		free(total_bytes);
+		free(bytes_used);
+		devs_found++;
+	}
+	if (devs_found < total) {
+		printf("\t*** Some devices missing\n");
+	}
+	printf("\n");
+}
+
+int do_show_filesystem(int argc, char **argv)
+{
+	struct list_head *all_uuids;
+	struct btrfs_fs_devices *fs_devices;
+	struct list_head *cur_uuid;
+	char *search = argv[0];
+	int ret;
+
+	ret = btrfs_scan_one_dir("/dev", 0);
+	if (ret){
+		fprintf(stderr, "ERROR: error %d while scanning\n", ret);
+		return 18;
+	}
+
+	all_uuids = btrfs_scanned_uuids();
+	list_for_each(cur_uuid, all_uuids) {
+		fs_devices = list_entry(cur_uuid, struct btrfs_fs_devices,
+					list);
+		if (search && uuid_search(fs_devices, search) == 0)
+			continue;
+		print_one_uuid(fs_devices);
+	}
+	printf("%s\n", BTRFS_BUILD_VERSION);
+	return 0;
+}
+
+int do_add_volume(int nargs, char **args)
+{
+
+	char	*mntpnt = args[nargs-1];
+	int	i, fdmnt, ret=0;
+
+
+	fdmnt = open_file_or_dir(mntpnt);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", mntpnt);
+		return 12;
+	}
+
+	for(i=0 ; i < (nargs-1) ; i++ ){
+		struct	btrfs_ioctl_vol_args ioctl_args;
+		int	devfd, res;
+		u64 dev_block_count = 0;
+		struct stat st;
+
+		devfd = open(args[i], O_RDWR);
+		if (!devfd) {
+			fprintf(stderr, "ERROR: Unable to open device '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		ret = fstat(devfd, &st);
+		if (ret) {
+			fprintf(stderr, "ERROR: Unable to stat '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		if (!S_ISBLK(st.st_mode)) {
+			fprintf(stderr, "ERROR: '%s' is not a block device\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+
+		res = btrfs_prepare_device(devfd, args[i], 1, &dev_block_count);
+		if (res) {
+			fprintf(stderr, "ERROR: Unable to init '%s'\n", args[i]);
+			close(devfd);
+			ret++;
+			continue;
+		}
+		close(devfd);
+
+		strcpy(ioctl_args.name, args[i]);
+		res = ioctl(fdmnt, BTRFS_IOC_ADD_DEV, &ioctl_args);
+		if(res<0){
+			fprintf(stderr, "ERROR: error adding the device '%s'\n", args[i]);
+			ret++;
+		}
+
+	}
+
+	close(fdmnt);
+	if( ret)
+		return ret+20;
+	else
+		return 0;
+
+}
+
+int do_balance(int argc, char **argv)
+{
+
+	int	fdmnt, ret=0;
+	char	*path = argv[0];
+	struct btrfs_ioctl_vol_args args;
+
+	fdmnt = open_file_or_dir(path);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
+	}
+
+	memset(&args, 0, sizeof(args));
+	ret = ioctl(fdmnt, BTRFS_IOC_BALANCE, &args);
+	close(fdmnt);
+	if(ret<0){
+		fprintf(stderr, "ERROR: balancing '%s'\n", path);
+
+		return 19;
+	}
+	return 0;
+}
+int do_remove_volume(int nargs, char **args)
+{
+
+	char	*mntpnt = args[nargs-1];
+	int	i, fdmnt, ret=0;
+
+	fdmnt = open_file_or_dir(mntpnt);
+	if (fdmnt < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", mntpnt);
+		return 12;
+	}
+
+	for(i=0 ; i < (nargs-1) ; i++ ){
+		struct	btrfs_ioctl_vol_args arg;
+		int	res;
+
+		strcpy(arg.name, args[i]);
+		res = ioctl(fdmnt, BTRFS_IOC_RM_DEV, &arg);
+		if(res<0){
+			fprintf(stderr, "ERROR: error removing the device '%s'\n", args[i]);
+			ret++;
+		}
+	}
+
+	close(fdmnt);
+	if( ret)
+		return ret+20;
+	else
+		return 0;
+}