[PATCH 0/2] v2, fi show, dev scan and lblkid

[PATCH 0/2] v2, fi show, dev scan and lblkid

[Anand Jain]

  This patch set is about
  use of lblkid for the btrfs disk scan and
  using this lblkid scan for the fi show and dev scan cli

  This includes the comments from David (to use lblkid)
  and Zach to show (btrfs fi show) info from kernel when
  disk is mounted and from the disks directly when disk
  is unmounted

v2:
  In an effort fix checkpath.pl errors as suggested in
  Wang's review, the two patches as below is merged
  into one

btrfs-progs: read from the kernel when disk is mounted
btrfs-progs: use lblkid to scan and filesystem show improvements

Anand Jain (2):
  btrfs-progs: v4, move out print in cmd_df to another function
  btrfs-progs: use kernel for mounted and lblkid to scan disks

 cmds-device.c     |   21 +---
 cmds-filesystem.c |  361 ++++++++++++++++++++++++++++++++++-------------------
 ctree.h           |   11 ++
 utils.c           |   55 ++++++++-
 utils.h           |    7 +-
 5 files changed, 304 insertions(+), 151 deletions(-)

[PATCH 1/2] btrfs-progs: v4, move out print in cmd_df to another function

[Anand Jain]

This is a prepatory work for the following btrfs fi show command
fixes. So that we have a function get_df to get the fs sizes

v4:
 fixes checkpatch.pl errors as suggested by Wang
v3:
 accepts Zach review comments
v2:
combined the other patches as below and rebase
 btrfs-progs: get string for the group profile and type

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 cmds-filesystem.c |  181 ++++++++++++++++++++++++++++------------------------
 ctree.h           |   11 +++
 2 files changed, 108 insertions(+), 84 deletions(-)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index a4e30ea..890d8fd 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -44,28 +44,51 @@ static const char * const cmd_df_usage[] = {
 	NULL
 };
 
-static int cmd_df(int argc, char **argv)
+static char *group_type_str(u64 flag)
 {
-	struct btrfs_ioctl_space_args *sargs, *sargs_orig;
-	u64 count = 0, i;
-	int ret;
-	int fd;
-	int e;
-	char *path;
-	DIR  *dirstream = NULL;
-
-	if (check_argc_exact(argc, 2))
-		usage(cmd_df_usage);
-
-	path = argv[1];
+	switch (flag & BTRFS_BLOCK_GROUP_TYPE_MASK) {
+	case BTRFS_BLOCK_GROUP_DATA:
+		return "data";
+	case BTRFS_BLOCK_GROUP_SYSTEM:
+		return "system";
+	case BTRFS_BLOCK_GROUP_METADATA:
+		return "metadata";
+	case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA:
+		return "mixed";
+	default:
+		return "unknown";
+	}
+}
 
-	fd = open_file_or_dir(path, &dirstream);
-	if (fd < 0) {
-		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
-		return 12;
+static char *group_profile_str(u64 flag)
+{
+	switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+	case 0:
+		return "single";
+	case BTRFS_BLOCK_GROUP_RAID0:
+		return "RAID0";
+	case BTRFS_BLOCK_GROUP_RAID1:
+		return "RAID1";
+	case BTRFS_BLOCK_GROUP_RAID5:
+		return "RAID5";
+	case BTRFS_BLOCK_GROUP_RAID6:
+		return "RAID6";
+	case BTRFS_BLOCK_GROUP_DUP:
+		return "DUP";
+	case BTRFS_BLOCK_GROUP_RAID10:
+		return "RAID10";
+	default:
+		return "unknown";
 	}
+}
 
-	sargs_orig = sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
+static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
+{
+	u64 count = 0;
+	int ret, e;
+	struct btrfs_ioctl_space_args *sargs;
+
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
 	if (!sargs)
 		return -ENOMEM;
 
@@ -75,89 +98,79 @@ static int cmd_df(int argc, char **argv)
 	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
 	e = errno;
 	if (ret) {
-		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
-			path, strerror(e));
-		goto out;
+		fprintf(stderr, "ERROR: couldn't get space info - %s\n",
+			strerror(e));
+		free(sargs);
+		return ret;
 	}
 	if (!sargs->total_spaces) {
-		ret = 0;
-		goto out;
+		free(sargs);
+		return 0;
 	}
-
 	count = sargs->total_spaces;
+	free(sargs);
 
-	sargs = realloc(sargs, sizeof(struct btrfs_ioctl_space_args) +
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args) +
 			(count * sizeof(struct btrfs_ioctl_space_info)));
-	if (!sargs) {
-		sargs = sargs_orig;
+	if (!sargs)
 		ret = -ENOMEM;
-		goto out;
-	}
 
 	sargs->space_slots = count;
 	sargs->total_spaces = 0;
-
 	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
 	e = errno;
 	if (ret) {
-		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
-			path, strerror(e));
-		goto out;
+		fprintf(stderr, "ERROR: get space info count %llu - %s\n",
+				count, strerror(e));
+		free(sargs);
+		return ret;
 	}
+	*sargs_ret = sargs;
+	return 0;
+}
 
-	for (i = 0; i < sargs->total_spaces; i++) {
-		char description[80];
-		int written = 0;
-		u64 flags = sargs->spaces[i].flags;
-
-		memset(description, 0, 80);
-
-		if (flags & BTRFS_BLOCK_GROUP_DATA) {
-			if (flags & BTRFS_BLOCK_GROUP_METADATA) {
-				snprintf(description, 14, "%s",
-					 "Data+Metadata");
-				written += 13;
-			} else {
-				snprintf(description, 5, "%s", "Data");
-				written += 4;
-			}
-		} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
-			snprintf(description, 7, "%s", "System");
-			written += 6;
-		} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
-			snprintf(description, 9, "%s", "Metadata");
-			written += 8;
-		}
+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));
+	}
+}
 
-		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
-			snprintf(description+written, 8, "%s", ", RAID0");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
-			snprintf(description+written, 8, "%s", ", RAID1");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
-			snprintf(description+written, 6, "%s", ", DUP");
-			written += 5;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
-			snprintf(description+written, 9, "%s", ", RAID10");
-			written += 8;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID5) {
-			snprintf(description+written, 9, "%s", ", RAID5");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID6) {
-			snprintf(description+written, 9, "%s", ", RAID6");
-			written += 7;
-		}
+static int cmd_df(int argc, char **argv)
+{
+	struct btrfs_ioctl_space_args *sargs = NULL;
+	int ret;
+	int fd;
+	char *path;
+	DIR  *dirstream = NULL;
 
-		printf("%s: total=%s, used=%s\n", description,
-			pretty_size(sargs->spaces[i].total_bytes),
-			pretty_size(sargs->spaces[i].used_bytes));
+	if (check_argc_exact(argc, 2))
+		usage(cmd_df_usage);
+
+	path = argv[1];
+
+	fd = open_file_or_dir(path, &dirstream);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
 	}
-out:
-	close_file_or_dir(fd, dirstream);
-	free(sargs);
+	ret = get_df(fd, &sargs);
 
-	return 0;
+	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 uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
diff --git a/ctree.h b/ctree.h
index 3c65d0a..3322c68 100644
--- a/ctree.h
+++ b/ctree.h
@@ -828,6 +828,17 @@ struct btrfs_csum_item {
 #define BTRFS_BLOCK_GROUP_RAID6    (1ULL << 8)
 #define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE
 
+#define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
+					 BTRFS_BLOCK_GROUP_SYSTEM |  \
+					 BTRFS_BLOCK_GROUP_METADATA)
+
+#define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
+					 BTRFS_BLOCK_GROUP_RAID1 |   \
+					 BTRFS_BLOCK_GROUP_RAID5 |   \
+					 BTRFS_BLOCK_GROUP_RAID6 |   \
+					 BTRFS_BLOCK_GROUP_DUP |     \
+					 BTRFS_BLOCK_GROUP_RAID10)
+
 /* used in struct btrfs_balance_args fields */
 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
 
-- 
1.7.1

[PATCH 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[Anand Jain]

As of now btrfs filesystem show reads directly from
disks. So sometimes output can be stale, mainly when
user want to verify their last operation like,
labeling or device delete or add... etc. so this
patch will read from the kernel ioctl if it finds
that disk is mounted.

Further, to scan for the disks this patch will use
lblkid, so that we don't have to manually scan the
/dev or /dev/mapper which means we don't need the
--all-devices options.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 cmds-device.c     |   21 +-----
 cmds-filesystem.c |  188 +++++++++++++++++++++++++++++++++++++++--------------
 utils.c           |   55 +++++++++++++++-
 utils.h           |    7 ++-
 4 files changed, 200 insertions(+), 71 deletions(-)

diff --git a/cmds-device.c b/cmds-device.c
index be2aaff..833ad30 100644
--- a/cmds-device.c
+++ b/cmds-device.c
@@ -186,7 +186,7 @@ static int cmd_rm_dev(int argc, char **argv)
 }
 
 static const char * const cmd_scan_dev_usage[] = {
-	"btrfs device scan [<--all-devices>|<device> [<device>...]]",
+	"btrfs device scan [<device>...]",
 	"Scan devices for a btrfs filesystem",
 	NULL
 };
@@ -194,28 +194,15 @@ static const char * const cmd_scan_dev_usage[] = {
 static int cmd_scan_dev(int argc, char **argv)
 {
 	int	i, fd, e;
-	int	where = BTRFS_SCAN_PROC;
 	int	devstart = 1;
 
-	if( argc > 1 && !strcmp(argv[1],"--all-devices")){
-		if (check_argc_max(argc, 2))
-			usage(cmd_scan_dev_usage);
-
-		where = BTRFS_SCAN_DEV;
-		devstart += 1;
-	}
-
-	if(argc<=devstart){
-		int ret;
+	if (argc <= devstart) {
 		printf("Scanning for Btrfs filesystems\n");
-		ret = scan_for_btrfs(where, 1);
-		if (ret){
-			fprintf(stderr, "ERROR: error %d while scanning\n", ret);
-			return 18;
-		}
+		scan_for_btrfs_v2(BTRFS_UPDATE_KERNEL);
 		return 0;
 	}
 
+	/* there are specific device/file to scan*/
 	fd = open("/dev/btrfs-control", O_RDWR);
 	if (fd < 0) {
 		perror("failed to open /dev/btrfs-control");
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 890d8fd..412f793 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -22,6 +22,9 @@
 #include <errno.h>
 #include <uuid/uuid.h>
 #include <ctype.h>
+#include <mntent.h>
+#include <fcntl.h>
+#include <linux/limits.h>
 
 #include "kerncompat.h"
 #include "ctree.h"
@@ -173,27 +176,6 @@ static int cmd_df(int argc, char **argv)
 	return ret;
 }
 
-static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
-{
-	char uuidbuf[37];
-	struct list_head *cur;
-	struct btrfs_device *device;
-	int search_len = strlen(search);
-
-	search_len = min(search_len, 37);
-	uuid_unparse(fs_devices->fsid, uuidbuf);
-	if (!strncmp(uuidbuf, search, search_len))
-		return 1;
-
-	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];
@@ -210,10 +192,10 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
 	else
 		printf("Label: none ");
 
-
 	total = device->total_devs;
-	printf(" uuid: %s\n\tTotal devices %llu FS bytes used %s\n", uuidbuf,
-	       (unsigned long long)total,
+
+	printf(" uuid: %s (unmounted)\n\tTotal devices %llu FS bytes used %s\n",
+		uuidbuf, (unsigned long long)total,
 	       pretty_size(device->super_bytes_used));
 
 	list_for_each(cur, &fs_devices->devices) {
@@ -232,8 +214,108 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
 	printf("\n");
 }
 
+/* adds up all the used spaces as reported by the space info ioctl
+ */
+static u64 cal_used_bytes(struct btrfs_ioctl_space_args *si)
+{
+	u64 ret = 0;
+	int i;
+	for (i = 0; i < si->total_spaces; i++)
+		ret += si->spaces[i].used_bytes;
+	return ret;
+}
+
+static int print_one_fs(struct btrfs_ioctl_fs_info_args *fi,
+		struct btrfs_ioctl_dev_info_args *di_n,
+		struct btrfs_ioctl_space_args *si_n, char *label, char *path)
+{
+	int i;
+	char uuidbuf[37];
+	struct btrfs_ioctl_dev_info_args *di = di_n;
+	u64 flags;
+
+	uuid_unparse(fi->fsid, uuidbuf);
+	printf("Label: %s  uuid: %s mounted: %s\n",
+		strlen(label) ? label : "none", uuidbuf, path);
+	printf("\tGroup profile:");
+	for (i = si_n->total_spaces - 1; i >= 0; i--) {
+		flags = si_n->spaces[i].flags;
+		if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+			continue;
+		printf(" %s: %s", group_type_str(flags),
+					group_profile_str(flags));
+		printf(" ");
+	}
+	printf("\n");
+
+	printf("\tTotal devices %llu FS bytes used %s\n",
+				fi->num_devices,
+			pretty_size(cal_used_bytes(si_n)));
+
+	for (i = 0; i < fi->num_devices; i++) {
+		di = (struct btrfs_ioctl_dev_info_args *)&di_n[i];
+		printf("\tdevid    %llu size %s used %s path %s\n",
+			di->devid,
+			pretty_size(di->total_bytes),
+			pretty_size(di->bytes_used),
+			di->path);
+	}
+
+	printf("\n");
+	return 0;
+}
+
+static int btrfs_scan_kernel(void *input, int type)
+{
+	int ret = 0, fd;
+	FILE *f;
+	struct mntent *mnt;
+	struct btrfs_ioctl_fs_info_args fi;
+	struct btrfs_ioctl_dev_info_args *di = NULL;
+	struct btrfs_ioctl_space_args *si;
+	char label[BTRFS_LABEL_SIZE];
+
+	f = setmntent("/proc/mounts", "r");
+	if (f == NULL)
+		return -errno;
+
+	while ((mnt = getmntent(f)) != NULL) {
+		if (strcmp(mnt->mnt_type, "btrfs"))
+			continue;
+		ret = get_fs_info(mnt->mnt_dir, &fi, &di);
+		if (ret)
+			return ret;
+
+		switch (type) {
+		case 0:
+			break;
+		case 1:
+			if (uuid_compare(fi.fsid, (u8 *)input))
+				continue;
+			break;
+		case 2:
+			if (strcmp(input, mnt->mnt_dir))
+				continue;
+			break;
+		default:
+			break;
+		}
+
+		fd = open(mnt->mnt_dir, O_RDONLY);
+		if (fd > 0 && !get_df(fd, &si)) {
+			get_label_mounted(mnt->mnt_dir, label);
+			print_one_fs(&fi, di, si, label, mnt->mnt_dir);
+			free(si);
+		}
+		if (fd > 0)
+			close(fd);
+		free(di);
+	}
+	return ret;
+}
+
 static const char * const cmd_show_usage[] = {
-	"btrfs filesystem show [--all-devices|<uuid>]",
+	"btrfs filesystem show [--mounted]",
 	"Show the structure of a filesystem",
 	"If no argument is given, structure of all present filesystems is shown.",
 	NULL
@@ -244,36 +326,42 @@ static int cmd_show(int argc, char **argv)
 	struct list_head *all_uuids;
 	struct btrfs_fs_devices *fs_devices;
 	struct list_head *cur_uuid;
-	char *search = 0;
-	int ret;
-	int where = BTRFS_SCAN_PROC;
-	int searchstart = 1;
-
-	if( argc > 1 && !strcmp(argv[1],"--all-devices")){
-		where = BTRFS_SCAN_DEV;
-		searchstart += 1;
-	}
+	int ret = 0;
+	int where = 0;
 
-	if (check_argc_max(argc, searchstart + 1))
+	if (check_argc_max(argc, 2))
 		usage(cmd_show_usage);
 
-	ret = scan_for_btrfs(where, 0);
-
-	if (ret){
-		fprintf(stderr, "ERROR: error %d while scanning\n", ret);
-		return 18;
-	}
-	
-	if(searchstart < argc)
-		search = argv[searchstart];
+	/* show only mounted btrfs disks */
+	if (argc > 1 && !strcmp(argv[1], "--mounted"))
+		where = BTRFS_SCAN_MOUNTED;
 
-	all_uuids = btrfs_scanned_uuids();
-	list_for_each(cur_uuid, all_uuids) {
-		fs_devices = list_entry(cur_uuid, struct btrfs_fs_devices,
+	switch (where) {
+	case 0:
+		/* no option : show both mounted and unmounted
+		 */
+		/* mounted */
+		ret = btrfs_scan_kernel(NULL, 0);
+		if (ret)
+			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
+				ret);
+
+		/* unmounted */
+		scan_for_btrfs_v2(!BTRFS_UPDATE_KERNEL);
+		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);
+			print_one_uuid(fs_devices);
+		}
+		break;
+	case BTRFS_SCAN_MOUNTED:
+		ret = btrfs_scan_kernel(NULL, 0);
+		if (ret)
+			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
+				ret);
+		break;
 	}
 	printf("%s\n", BTRFS_BUILD_VERSION);
 	return 0;
diff --git a/utils.c b/utils.c
index 86ee948..de182e0 100644
--- a/utils.c
+++ b/utils.c
@@ -680,9 +680,9 @@ int is_block_device(const char *path) {
  * Find the mount point for a mounted device.
  * On success, returns 0 with mountpoint in *mp.
  * On failure, returns -errno (not mounted yields -EINVAL)
- * Is noisy on failures, expects to be given a mounted device.
  */
-static int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
+int get_btrfs_mount(const char *dev, char *mp, size_t mp_size)
+{
 	int ret;
 	int fd = -1;
 
@@ -707,7 +707,6 @@ static int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
 
 	ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
 	if (!ret) {
-		fprintf(stderr, "%s is not a mounted btrfs device\n", dev);
 		ret = -EINVAL;
 	} else { /* mounted, all good */
 		ret = 0;
@@ -1133,6 +1132,56 @@ fail:
 	return ret;
 }
 
+int test_skip_this_disk(char *path)
+{
+	int fd;
+	/* this will eliminate disks which are mounted (btrfs)
+	 * and non-dm disk path when dm is enabled
+	 */
+	fd = open(path, O_RDWR|O_EXCL);
+	if (fd < 0)
+		return 1;
+	close(fd);
+	return 0;
+}
+
+void scan_for_btrfs_v2(int update_kernel)
+{
+	int fd = -1;
+	u64 num_devices;
+	struct btrfs_fs_devices *tmp_devices;
+	blkid_dev_iterate iter = NULL;
+	blkid_dev dev = NULL;
+	blkid_cache cache = NULL;
+	char path[PATH_MAX];
+
+	if (blkid_get_cache(&cache, 0) < 0) {
+		printf("ERROR: lblkid cache get failed\n");
+		return;
+	}
+	blkid_probe_all(cache);
+	iter = blkid_dev_iterate_begin(cache);
+	blkid_dev_set_search(iter, "TYPE", "btrfs");
+	while (blkid_dev_next(iter, &dev) == 0) {
+		dev = blkid_verify(cache, dev);
+		if (!dev)
+			continue;
+		/* if we are here its definitly a btrfs disk*/
+		strcpy(path, blkid_dev_devname(dev));
+		if (test_skip_this_disk(path))
+			continue;
+
+		fd = open(path, O_RDONLY);
+		btrfs_scan_one_device(fd, path, &tmp_devices,
+				&num_devices, BTRFS_SUPER_INFO_OFFSET);
+		close(fd);
+		fd = -1;
+		if (update_kernel)
+			btrfs_register_one_device(path);
+	}
+	blkid_dev_iterate_end(iter);
+}
+
 int btrfs_scan_for_fsid(int run_ioctls)
 {
 	int ret;
diff --git a/utils.h b/utils.h
index ec06a82..4b449b8 100644
--- a/utils.h
+++ b/utils.h
@@ -25,8 +25,11 @@
 
 #define BTRFS_MKFS_SYSTEM_GROUP_SIZE (4 * 1024 * 1024)
 
-#define BTRFS_SCAN_PROC	1
+#define BTRFS_SCAN_PROC		1
 #define BTRFS_SCAN_DEV		2
+#define BTRFS_SCAN_MOUNTED	3
+
+#define BTRFS_UPDATE_KERNEL	1
 
 int make_btrfs(int fd, const char *device, const char *label,
 	       u64 blocks[6], u64 num_bytes, u32 nodesize,
@@ -74,7 +77,9 @@ u64 btrfs_device_size(int fd, struct stat *st);
 #define strncpy_null(dest, src) __strncpy__null(dest, src, sizeof(dest))
 int test_dev_for_mkfs(char *file, int force_overwrite, char *estr);
 int scan_for_btrfs(int where, int update_kernel);
+void scan_for_btrfs_v2(int update_kernel);
 int get_label_mounted(const char *mount_path, char *labelp);
 int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
 	u64 dev_cnt, int mixed, char *estr);
+int get_btrfs_mount(const char *dev, char *mp, size_t mp_size);
 #endif
-- 
1.7.1

[PATCH 1/2 resend] btrfs-progs: v4, move out print in cmd_df to another function

[Anand Jain]

This is a prepatory work for the following btrfs fi show command
fixes. So that we have a function get_df to get the fs sizes

v4:
 fixes checkpatch.pl errors as suggested by Wang
v3:
 accepts Zach review comments
v2:
combined the other patches as below and rebase
 btrfs-progs: get string for the group profile and type

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 cmds-filesystem.c |  181 ++++++++++++++++++++++++++++------------------------
 ctree.h           |   11 +++
 2 files changed, 108 insertions(+), 84 deletions(-)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index ca0855b..61b30d3 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -44,28 +44,51 @@ static const char * const cmd_df_usage[] = {
 	NULL
 };
 
-static int cmd_df(int argc, char **argv)
+static char *group_type_str(u64 flag)
 {
-	struct btrfs_ioctl_space_args *sargs, *sargs_orig;
-	u64 count = 0, i;
-	int ret;
-	int fd;
-	int e;
-	char *path;
-	DIR  *dirstream = NULL;
-
-	if (check_argc_exact(argc, 2))
-		usage(cmd_df_usage);
-
-	path = argv[1];
+	switch (flag & BTRFS_BLOCK_GROUP_TYPE_MASK) {
+	case BTRFS_BLOCK_GROUP_DATA:
+		return "data";
+	case BTRFS_BLOCK_GROUP_SYSTEM:
+		return "system";
+	case BTRFS_BLOCK_GROUP_METADATA:
+		return "metadata";
+	case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA:
+		return "mixed";
+	default:
+		return "unknown";
+	}
+}
 
-	fd = open_file_or_dir(path, &dirstream);
-	if (fd < 0) {
-		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
-		return 12;
+static char *group_profile_str(u64 flag)
+{
+	switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+	case 0:
+		return "single";
+	case BTRFS_BLOCK_GROUP_RAID0:
+		return "RAID0";
+	case BTRFS_BLOCK_GROUP_RAID1:
+		return "RAID1";
+	case BTRFS_BLOCK_GROUP_RAID5:
+		return "RAID5";
+	case BTRFS_BLOCK_GROUP_RAID6:
+		return "RAID6";
+	case BTRFS_BLOCK_GROUP_DUP:
+		return "DUP";
+	case BTRFS_BLOCK_GROUP_RAID10:
+		return "RAID10";
+	default:
+		return "unknown";
 	}
+}
 
-	sargs_orig = sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
+static int get_df(int fd, struct btrfs_ioctl_space_args **sargs_ret)
+{
+	u64 count = 0;
+	int ret, e;
+	struct btrfs_ioctl_space_args *sargs;
+
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args));
 	if (!sargs)
 		return -ENOMEM;
 
@@ -75,89 +98,79 @@ static int cmd_df(int argc, char **argv)
 	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
 	e = errno;
 	if (ret) {
-		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
-			path, strerror(e));
-		goto out;
+		fprintf(stderr, "ERROR: couldn't get space info - %s\n",
+			strerror(e));
+		free(sargs);
+		return ret;
 	}
 	if (!sargs->total_spaces) {
-		ret = 0;
-		goto out;
+		free(sargs);
+		return 0;
 	}
-
 	count = sargs->total_spaces;
+	free(sargs);
 
-	sargs = realloc(sargs, sizeof(struct btrfs_ioctl_space_args) +
+	sargs = malloc(sizeof(struct btrfs_ioctl_space_args) +
 			(count * sizeof(struct btrfs_ioctl_space_info)));
-	if (!sargs) {
-		sargs = sargs_orig;
+	if (!sargs)
 		ret = -ENOMEM;
-		goto out;
-	}
 
 	sargs->space_slots = count;
 	sargs->total_spaces = 0;
-
 	ret = ioctl(fd, BTRFS_IOC_SPACE_INFO, sargs);
 	e = errno;
 	if (ret) {
-		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
-			path, strerror(e));
-		goto out;
+		fprintf(stderr, "ERROR: get space info count %llu - %s\n",
+				count, strerror(e));
+		free(sargs);
+		return ret;
 	}
+	*sargs_ret = sargs;
+	return 0;
+}
 
-	for (i = 0; i < sargs->total_spaces; i++) {
-		char description[80];
-		int written = 0;
-		u64 flags = sargs->spaces[i].flags;
-
-		memset(description, 0, 80);
-
-		if (flags & BTRFS_BLOCK_GROUP_DATA) {
-			if (flags & BTRFS_BLOCK_GROUP_METADATA) {
-				snprintf(description, 14, "%s",
-					 "Data+Metadata");
-				written += 13;
-			} else {
-				snprintf(description, 5, "%s", "Data");
-				written += 4;
-			}
-		} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
-			snprintf(description, 7, "%s", "System");
-			written += 6;
-		} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
-			snprintf(description, 9, "%s", "Metadata");
-			written += 8;
-		}
+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));
+	}
+}
 
-		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
-			snprintf(description+written, 8, "%s", ", RAID0");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
-			snprintf(description+written, 8, "%s", ", RAID1");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
-			snprintf(description+written, 6, "%s", ", DUP");
-			written += 5;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
-			snprintf(description+written, 9, "%s", ", RAID10");
-			written += 8;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID5) {
-			snprintf(description+written, 9, "%s", ", RAID5");
-			written += 7;
-		} else if (flags & BTRFS_BLOCK_GROUP_RAID6) {
-			snprintf(description+written, 9, "%s", ", RAID6");
-			written += 7;
-		}
+static int cmd_df(int argc, char **argv)
+{
+	struct btrfs_ioctl_space_args *sargs = NULL;
+	int ret;
+	int fd;
+	char *path;
+	DIR  *dirstream = NULL;
 
-		printf("%s: total=%s, used=%s\n", description,
-			pretty_size(sargs->spaces[i].total_bytes),
-			pretty_size(sargs->spaces[i].used_bytes));
+	if (check_argc_exact(argc, 2))
+		usage(cmd_df_usage);
+
+	path = argv[1];
+
+	fd = open_file_or_dir(path, &dirstream);
+	if (fd < 0) {
+		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+		return 12;
 	}
-out:
-	close_file_or_dir(fd, dirstream);
-	free(sargs);
+	ret = get_df(fd, &sargs);
 
-	return 0;
+	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 uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
diff --git a/ctree.h b/ctree.h
index 35d1ba4..f6b1ddc 100644
--- a/ctree.h
+++ b/ctree.h
@@ -831,6 +831,17 @@ struct btrfs_csum_item {
 #define BTRFS_BLOCK_GROUP_RAID6    (1ULL << 8)
 #define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE
 
+#define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
+					 BTRFS_BLOCK_GROUP_SYSTEM |  \
+					 BTRFS_BLOCK_GROUP_METADATA)
+
+#define BTRFS_BLOCK_GROUP_PROFILE_MASK	(BTRFS_BLOCK_GROUP_RAID0 |   \
+					 BTRFS_BLOCK_GROUP_RAID1 |   \
+					 BTRFS_BLOCK_GROUP_RAID5 |   \
+					 BTRFS_BLOCK_GROUP_RAID6 |   \
+					 BTRFS_BLOCK_GROUP_DUP |     \
+					 BTRFS_BLOCK_GROUP_RAID10)
+
 /* used in struct btrfs_balance_args fields */
 #define BTRFS_AVAIL_ALLOC_BIT_SINGLE	(1ULL << 48)
 
-- 
1.7.1

[PATCH v2 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[Anand Jain]

As of now btrfs filesystem show reads directly from
disks. So sometimes output can be stale, mainly when
user want to verify their last operation like,
labeling or device delete or add... etc. so this
patch will read from the kernel ioctl if it finds
that disk is mounted.

Further, to scan for the disks this patch will use
lblkid, so that we don't have to manually scan the
/dev or /dev/mapper which means we don't need the
all-devices options.

v2:
  rebase on the latest integration integration-20130903
  at present

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 cmds-device.c     |   21 +-----
 cmds-filesystem.c |  188 +++++++++++++++++++++++++++++++++++++++--------------
 utils.c           |   55 +++++++++++++++-
 utils.h           |    7 ++-
 4 files changed, 200 insertions(+), 71 deletions(-)

diff --git a/cmds-device.c b/cmds-device.c
index 7524d08..f3d4b67 100644
--- a/cmds-device.c
+++ b/cmds-device.c
@@ -177,7 +177,7 @@ static int cmd_rm_dev(int argc, char **argv)
 }
 
 static const char * const cmd_scan_dev_usage[] = {
-	"btrfs device scan [<--all-devices>|<device> [<device>...]]",
+	"btrfs device scan [<device>...]",
 	"Scan devices for a btrfs filesystem",
 	NULL
 };
@@ -185,28 +185,15 @@ static const char * const cmd_scan_dev_usage[] = {
 static int cmd_scan_dev(int argc, char **argv)
 {
 	int	i, fd, e;
-	int	where = BTRFS_SCAN_PROC;
 	int	devstart = 1;
 
-	if( argc > 1 && !strcmp(argv[1],"--all-devices")){
-		if (check_argc_max(argc, 2))
-			usage(cmd_scan_dev_usage);
-
-		where = BTRFS_SCAN_DEV;
-		devstart += 1;
-	}
-
-	if(argc<=devstart){
-		int ret;
+	if (argc <= devstart) {
 		printf("Scanning for Btrfs filesystems\n");
-		ret = scan_for_btrfs(where, 1);
-		if (ret){
-			fprintf(stderr, "ERROR: error %d while scanning\n", ret);
-			return 18;
-		}
+		scan_for_btrfs_v2(BTRFS_UPDATE_KERNEL);
 		return 0;
 	}
 
+	/* there are specific device/file to scan*/
 	fd = open("/dev/btrfs-control", O_RDWR);
 	if (fd < 0) {
 		perror("failed to open /dev/btrfs-control");
diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 61b30d3..21f2096 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -22,6 +22,9 @@
 #include <errno.h>
 #include <uuid/uuid.h>
 #include <ctype.h>
+#include <mntent.h>
+#include <fcntl.h>
+#include <linux/limits.h>
 
 #include "kerncompat.h"
 #include "ctree.h"
@@ -173,27 +176,6 @@ static int cmd_df(int argc, char **argv)
 	return ret;
 }
 
-static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
-{
-	char uuidbuf[37];
-	struct list_head *cur;
-	struct btrfs_device *device;
-	int search_len = strlen(search);
-
-	search_len = min(search_len, 37);
-	uuid_unparse(fs_devices->fsid, uuidbuf);
-	if (!strncmp(uuidbuf, search, search_len))
-		return 1;
-
-	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];
@@ -210,10 +192,10 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
 	else
 		printf("Label: none ");
 
-
 	total = device->total_devs;
-	printf(" uuid: %s\n\tTotal devices %llu FS bytes used %s\n", uuidbuf,
-	       (unsigned long long)total,
+
+	printf(" uuid: %s (unmounted)\n\tTotal devices %llu FS bytes used %s\n",
+		uuidbuf, (unsigned long long)total,
 	       pretty_size(device->super_bytes_used));
 
 	list_for_each(cur, &fs_devices->devices) {
@@ -232,8 +214,108 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
 	printf("\n");
 }
 
+/* adds up all the used spaces as reported by the space info ioctl
+ */
+static u64 cal_used_bytes(struct btrfs_ioctl_space_args *si)
+{
+	u64 ret = 0;
+	int i;
+	for (i = 0; i < si->total_spaces; i++)
+		ret += si->spaces[i].used_bytes;
+	return ret;
+}
+
+static int print_one_fs(struct btrfs_ioctl_fs_info_args *fi,
+		struct btrfs_ioctl_dev_info_args *di_n,
+		struct btrfs_ioctl_space_args *si_n, char *label, char *path)
+{
+	int i;
+	char uuidbuf[37];
+	struct btrfs_ioctl_dev_info_args *di = di_n;
+	u64 flags;
+
+	uuid_unparse(fi->fsid, uuidbuf);
+	printf("Label: %s  uuid: %s mounted: %s\n",
+		strlen(label) ? label : "none", uuidbuf, path);
+	printf("\tGroup profile:");
+	for (i = si_n->total_spaces - 1; i >= 0; i--) {
+		flags = si_n->spaces[i].flags;
+		if (flags & BTRFS_BLOCK_GROUP_SYSTEM)
+			continue;
+		printf(" %s: %s", group_type_str(flags),
+					group_profile_str(flags));
+		printf(" ");
+	}
+	printf("\n");
+
+	printf("\tTotal devices %llu FS bytes used %s\n",
+				fi->num_devices,
+			pretty_size(cal_used_bytes(si_n)));
+
+	for (i = 0; i < fi->num_devices; i++) {
+		di = (struct btrfs_ioctl_dev_info_args *)&di_n[i];
+		printf("\tdevid    %llu size %s used %s path %s\n",
+			di->devid,
+			pretty_size(di->total_bytes),
+			pretty_size(di->bytes_used),
+			di->path);
+	}
+
+	printf("\n");
+	return 0;
+}
+
+static int btrfs_scan_kernel(void *input, int type)
+{
+	int ret = 0, fd;
+	FILE *f;
+	struct mntent *mnt;
+	struct btrfs_ioctl_fs_info_args fi;
+	struct btrfs_ioctl_dev_info_args *di = NULL;
+	struct btrfs_ioctl_space_args *si;
+	char label[BTRFS_LABEL_SIZE];
+
+	f = setmntent("/proc/mounts", "r");
+	if (f == NULL)
+		return -errno;
+
+	while ((mnt = getmntent(f)) != NULL) {
+		if (strcmp(mnt->mnt_type, "btrfs"))
+			continue;
+		ret = get_fs_info(mnt->mnt_dir, &fi, &di);
+		if (ret)
+			return ret;
+
+		switch (type) {
+		case 0:
+			break;
+		case 1:
+			if (uuid_compare(fi.fsid, (u8 *)input))
+				continue;
+			break;
+		case 2:
+			if (strcmp(input, mnt->mnt_dir))
+				continue;
+			break;
+		default:
+			break;
+		}
+
+		fd = open(mnt->mnt_dir, O_RDONLY);
+		if (fd > 0 && !get_df(fd, &si)) {
+			get_label_mounted(mnt->mnt_dir, label);
+			print_one_fs(&fi, di, si, label, mnt->mnt_dir);
+			free(si);
+		}
+		if (fd > 0)
+			close(fd);
+		free(di);
+	}
+	return ret;
+}
+
 static const char * const cmd_show_usage[] = {
-	"btrfs filesystem show [--all-devices|<uuid>]",
+	"btrfs filesystem show [--mounted]",
 	"Show the structure of a filesystem",
 	"If no argument is given, structure of all present filesystems is shown.",
 	NULL
@@ -244,36 +326,42 @@ static int cmd_show(int argc, char **argv)
 	struct list_head *all_uuids;
 	struct btrfs_fs_devices *fs_devices;
 	struct list_head *cur_uuid;
-	char *search = NULL;
-	int ret;
-	int where = BTRFS_SCAN_PROC;
-	int searchstart = 1;
-
-	if( argc > 1 && !strcmp(argv[1],"--all-devices")){
-		where = BTRFS_SCAN_DEV;
-		searchstart += 1;
-	}
+	int ret = 0;
+	int where = 0;
 
-	if (check_argc_max(argc, searchstart + 1))
+	if (check_argc_max(argc, 2))
 		usage(cmd_show_usage);
 
-	ret = scan_for_btrfs(where, 0);
-
-	if (ret){
-		fprintf(stderr, "ERROR: error %d while scanning\n", ret);
-		return 18;
-	}
-	
-	if(searchstart < argc)
-		search = argv[searchstart];
+	/* show only mounted btrfs disks */
+	if (argc > 1 && !strcmp(argv[1], "--mounted"))
+		where = BTRFS_SCAN_MOUNTED;
 
-	all_uuids = btrfs_scanned_uuids();
-	list_for_each(cur_uuid, all_uuids) {
-		fs_devices = list_entry(cur_uuid, struct btrfs_fs_devices,
+	switch (where) {
+	case 0:
+		/* no option : show both mounted and unmounted
+		 */
+		/* mounted */
+		ret = btrfs_scan_kernel(NULL, 0);
+		if (ret)
+			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
+				ret);
+
+		/* unmounted */
+		scan_for_btrfs_v2(!BTRFS_UPDATE_KERNEL);
+		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);
+			print_one_uuid(fs_devices);
+		}
+		break;
+	case BTRFS_SCAN_MOUNTED:
+		ret = btrfs_scan_kernel(NULL, 0);
+		if (ret)
+			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
+				ret);
+		break;
 	}
 	printf("%s\n", BTRFS_BUILD_VERSION);
 	return 0;
diff --git a/utils.c b/utils.c
index d022d58..82672a7 100644
--- a/utils.c
+++ b/utils.c
@@ -685,9 +685,9 @@ int is_block_device(const char *path) {
  * Find the mount point for a mounted device.
  * On success, returns 0 with mountpoint in *mp.
  * On failure, returns -errno (not mounted yields -EINVAL)
- * Is noisy on failures, expects to be given a mounted device.
  */
-static int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
+int get_btrfs_mount(const char *dev, char *mp, size_t mp_size)
+{
 	int ret;
 	int fd = -1;
 
@@ -712,7 +712,6 @@ static int get_btrfs_mount(const char *dev, char *mp, size_t mp_size) {
 
 	ret = check_mounted_where(fd, dev, mp, mp_size, NULL);
 	if (!ret) {
-		fprintf(stderr, "%s is not a mounted btrfs device\n", dev);
 		ret = -EINVAL;
 	} else { /* mounted, all good */
 		ret = 0;
@@ -1138,6 +1137,56 @@ fail:
 	return ret;
 }
 
+int test_skip_this_disk(char *path)
+{
+	int fd;
+	/* this will eliminate disks which are mounted (btrfs)
+	 * and non-dm disk path when dm is enabled
+	 */
+	fd = open(path, O_RDWR|O_EXCL);
+	if (fd < 0)
+		return 1;
+	close(fd);
+	return 0;
+}
+
+void scan_for_btrfs_v2(int update_kernel)
+{
+	int fd = -1;
+	u64 num_devices;
+	struct btrfs_fs_devices *tmp_devices;
+	blkid_dev_iterate iter = NULL;
+	blkid_dev dev = NULL;
+	blkid_cache cache = NULL;
+	char path[PATH_MAX];
+
+	if (blkid_get_cache(&cache, 0) < 0) {
+		printf("ERROR: lblkid cache get failed\n");
+		return;
+	}
+	blkid_probe_all(cache);
+	iter = blkid_dev_iterate_begin(cache);
+	blkid_dev_set_search(iter, "TYPE", "btrfs");
+	while (blkid_dev_next(iter, &dev) == 0) {
+		dev = blkid_verify(cache, dev);
+		if (!dev)
+			continue;
+		/* if we are here its definitly a btrfs disk*/
+		strcpy(path, blkid_dev_devname(dev));
+		if (test_skip_this_disk(path))
+			continue;
+
+		fd = open(path, O_RDONLY);
+		btrfs_scan_one_device(fd, path, &tmp_devices,
+				&num_devices, BTRFS_SUPER_INFO_OFFSET);
+		close(fd);
+		fd = -1;
+		if (update_kernel)
+			btrfs_register_one_device(path);
+	}
+	blkid_dev_iterate_end(iter);
+}
+
 int btrfs_scan_for_fsid(int run_ioctls)
 {
 	int ret;
diff --git a/utils.h b/utils.h
index dc795f4..6446e0a 100644
--- a/utils.h
+++ b/utils.h
@@ -25,8 +25,11 @@
 
 #define BTRFS_MKFS_SYSTEM_GROUP_SIZE (4 * 1024 * 1024)
 
-#define BTRFS_SCAN_PROC	1
+#define BTRFS_SCAN_PROC		1
 #define BTRFS_SCAN_DEV		2
+#define BTRFS_SCAN_MOUNTED	3
+
+#define BTRFS_UPDATE_KERNEL	1
 
 int make_btrfs(int fd, const char *device, const char *label,
 	       u64 blocks[6], u64 num_bytes, u32 nodesize,
@@ -74,8 +77,10 @@ u64 btrfs_device_size(int fd, struct stat *st);
 #define strncpy_null(dest, src) __strncpy__null(dest, src, sizeof(dest))
 int test_dev_for_mkfs(char *file, int force_overwrite, char *estr);
 int scan_for_btrfs(int where, int update_kernel);
+void scan_for_btrfs_v2(int update_kernel);
 int get_label_mounted(const char *mount_path, char *labelp);
 int test_num_disk_vs_raid(u64 metadata_profile, u64 data_profile,
 	u64 dev_cnt, int mixed, char *estr);
 int is_vol_small(char *file);
+int get_btrfs_mount(const char *dev, char *mp, size_t mp_size);
 #endif
-- 
1.7.1

Re: [PATCH 1/2 resend] btrfs-progs: v4, move out print in cmd_df to another function

[David Sterba]

On Fri, Sep 06, 2013 at 05:37:52PM +0800, Anand Jain wrote:
> +static char *group_type_str(u64 flag)
>  {
> -	struct btrfs_ioctl_space_args *sargs, *sargs_orig;
> -	u64 count = 0, i;
> -	int ret;
> -	int fd;
> -	int e;
> -	char *path;
> -	DIR  *dirstream = NULL;
> -
> -	if (check_argc_exact(argc, 2))
> -		usage(cmd_df_usage);
> -
> -	path = argv[1];
> +	switch (flag & BTRFS_BLOCK_GROUP_TYPE_MASK) {
> +	case BTRFS_BLOCK_GROUP_DATA:
> +		return "data";
> +	case BTRFS_BLOCK_GROUP_SYSTEM:
> +		return "system";
> +	case BTRFS_BLOCK_GROUP_METADATA:
> +		return "metadata";
> +	case BTRFS_BLOCK_GROUP_DATA|BTRFS_BLOCK_GROUP_METADATA:
> +		return "mixed";

I think the profile names should stay unchanged, ie Data, System etc,
and Data+Metadata instead of mixed. We can change the output format
later, but for this preparatory patch I'd stick with what it is.

> +	default:
> +		return "unknown";
> +	}
> +}
>  
> -	fd = open_file_or_dir(path, &dirstream);
> -	if (fd < 0) {
> -		fprintf(stderr, "ERROR: can't access to '%s'\n", path);
> -		return 12;
> +static char *group_profile_str(u64 flag)
> +{
> +	switch (flag & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
> +	case 0:
> +		return "single";

The 'single' profile was not explicitly mentioned before, I tend to
think that it's better to be consistent with the rest and add it as you
do in this patch.

Sample output:

$ ./btrfs fi df /mnt/enospc/mnt
data, single: total=5.92GiB, used=4.41GiB
system, DUP: total=8.00MiB, used=4.00KiB
system, single: total=4.00MiB, used=0.00
metadata, DUP: total=1.02GiB, used=828.10MiB
metadata, single: total=8.00MiB, used=0.00

looks imho ok.

Re: [PATCH v2 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[David Sterba]

On Fri, Sep 06, 2013 at 05:37:53PM +0800, Anand Jain wrote:
> Further, to scan for the disks this patch will use
> lblkid, so that we don't have to manually scan the
> /dev or /dev/mapper which means we don't need the
> all-devices options.

Thanks for implementing it! I found a few things to fix, comments below.

I wonder if we should keep --all-devices as a last resort fallback eg.
when blkid cache is not available.

> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> -static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
> -{
> -	char uuidbuf[37];
> -	struct list_head *cur;
> -	struct btrfs_device *device;
> -	int search_len = strlen(search);
> -
> -	search_len = min(search_len, 37);
> -	uuid_unparse(fs_devices->fsid, uuidbuf);
> -	if (!strncmp(uuidbuf, search, search_len))
> -		return 1;
> -
> -	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;
> -}

This is removing functionality and I don't understand why. It's used for

$ btrfs fi show 9f135b48-cc15-424b-8730-a6432c67dc34
[prints only the given filesystem]

and with your patch does not work as such. Can it be implemented on top
of the code you're adding in this patch? If yes, please make a separate
patch for that.

> @@ -232,8 +214,108 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
>  	printf("\n");
>  }
>  
> +/* adds up all the used spaces as reported by the space info ioctl
> + */
> +static u64 cal_used_bytes(struct btrfs_ioctl_space_args *si)

calc_used_bytes

> +static int btrfs_scan_kernel(void *input, int type)
> +{
> +	int ret = 0, fd;
> +	FILE *f;
> +	struct mntent *mnt;
> +	struct btrfs_ioctl_fs_info_args fi;
> +	struct btrfs_ioctl_dev_info_args *di = NULL;
> +	struct btrfs_ioctl_space_args *si;

the variable names are not very descriptive

> +	char label[BTRFS_LABEL_SIZE];
> +
> +	f = setmntent("/proc/mounts", "r");

should be /proc/self/mounts

> +	if (f == NULL)
> +		return -errno;

man says that setmntent does not set errno 

> +
> +	while ((mnt = getmntent(f)) != NULL) {
> +		if (strcmp(mnt->mnt_type, "btrfs"))
> +			continue;
> +		ret = get_fs_info(mnt->mnt_dir, &fi, &di);
> +		if (ret)
> +			return ret;
> +
> +		switch (type) {

Please add defines instead of the integers representing 'type'.

> +		case 0:
> +			break;
> +		case 1:
> +			if (uuid_compare(fi.fsid, (u8 *)input))
> +				continue;
> +			break;
> +		case 2:
> +			if (strcmp(input, mnt->mnt_dir))
> +				continue;
> +			break;

I haven't seen 1 and 2 used anywhere

> +		default:
> +			break;
> +		}
> +
> +		fd = open(mnt->mnt_dir, O_RDONLY);
> +		if (fd > 0 && !get_df(fd, &si)) {
> +			get_label_mounted(mnt->mnt_dir, label);
> +			print_one_fs(&fi, di, si, label, mnt->mnt_dir);
> +			free(si);
> +		}
> +		if (fd > 0)
> +			close(fd);
> +		free(di);
> +	}
> +	return ret;
> +}
> @@ -244,36 +326,42 @@ static int cmd_show(int argc, char **argv)
> +	/* show only mounted btrfs disks */
> +	if (argc > 1 && !strcmp(argv[1], "--mounted"))
> +		where = BTRFS_SCAN_MOUNTED;
>  
> -	all_uuids = btrfs_scanned_uuids();
> -	list_for_each(cur_uuid, all_uuids) {
> -		fs_devices = list_entry(cur_uuid, struct btrfs_fs_devices,
> +	switch (where) {
> +	case 0:
> +		/* no option : show both mounted and unmounted
> +		 */
> +		/* mounted */
> +		ret = btrfs_scan_kernel(NULL, 0);
> +		if (ret)
> +			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
> +				ret);

I see this warning and there are no mounted filesystems listed in the
output:

$ ./btrfs fi show
ERROR: scan kernel failed, -1


> +
> +		/* unmounted */
> +		scan_for_btrfs_v2(!BTRFS_UPDATE_KERNEL);
> +		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);
> +			print_one_uuid(fs_devices);
> +		}
> +		break;
> +	case BTRFS_SCAN_MOUNTED:
> +		ret = btrfs_scan_kernel(NULL, 0);
> +		if (ret)
> +			fprintf(stderr, "ERROR: scan kernel failed, %d\n",
> +				ret);
> +		break;
>  	}
>  	printf("%s\n", BTRFS_BUILD_VERSION);
>  	return 0;

Re: [PATCH v2 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[Anand Jain]

> Thanks for implementing it! I found a few things to fix, comments below.
>
> I wonder if we should keep --all-devices as a last resort fallback eg.

  Any idea whats the real use of --all-devices option anyway
  I am unsure. Anyway will restore --all-devices so now.

  all other suggestion were considered as well.

> I see this warning and there are no mounted filesystems listed in the
> output:
>
> $ ./btrfs fi show
> ERROR: scan kernel failed, -1
>

when does this happen ? I can't reproduce it.

Thanks, Anand

Re: [PATCH v2 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[David Sterba]

On Fri, Sep 13, 2013 at 06:49:10PM +0800, Anand Jain wrote:
> >I wonder if we should keep --all-devices as a last resort fallback eg.
> 
>  Any idea whats the real use of --all-devices option anyway
>  I am unsure. Anyway will restore --all-devices so now.

That's when udev breaks or is not present on the system at all.

http://thread.gmane.org/gmane.comp.file-systems.btrfs/11336

It's hard to know if there are users or not, from the thread above there
is at least one.

A good practice is to leave some deprecation period before removing a
functionality, so we should rather add a warning that the option is
about to be removed -- because udev is everywhere and computers don't
break, right?

> >I see this warning and there are no mounted filesystems listed in the
> >output:
> >
> >$ ./btrfs fi show
> >ERROR: scan kernel failed, -1
> 
> when does this happen ? I can't reproduce it.

Reproduced with today's linus tree (btrfs pull is there), progs contain the
patches in question:

blkid lists btrfs filesysems:
/dev/sda5
/dev/sda6
/dev/sda7
/dev/sda8
/dev/sda9
/dev/sda11
/dev/sda15
/dev/sdb

mounted filesystems:
/dev/sda5 /mnt/a1 btrfs rw,relatime,space_cache 0 0
/dev/sdb /mnt/test btrfs rw,relatime,space_cache 0 0

$ ./btrfs fi show
ERROR: scan kernel failed, -1
Label: none  uuid: 7c7c948e-c8bc-40fb-88e3-19a3dd4fe6f9 (unmounted)
        Total devices 2 FS bytes used 288.00KiB
        devid    2 size 4.04GiB used 0.00 path /dev/sda15
        *** Some devices missing

Label: none  uuid: a7e96a20-eceb-4593-a836-a8657c66e24b (unmounted)
        Total devices 2 FS bytes used 6.87GiB
        devid    1 size 10.00GiB used 9.03GiB path /dev/sda11
        devid    0 size 10.00GiB used 4.01GiB path /dev/sda9

sda6/7/8/9 belong to sda5 and are not listed here

Re: [PATCH v2 2/2] btrfs-progs: use kernel for mounted and lblkid to scan disks

[David Sterba]

On Fri, Sep 13, 2013 at 05:56:46PM +0200, David Sterba wrote:
> Reproduced with today's linus tree (btrfs pull is there), progs contain the
> patches in question:

Reproduces with the updated patches you sent today.