[RFC][btrfs-progs] add command btrfs filesystem info

[RFC][btrfs-progs] add command btrfs filesystem info

[Goffredo Baroncelli]

Hi all

the aim of this patch is to add the command "btrfs filesystem info" to 
show some filesystem information. Example:

$ sudo btrfs-progs/btrfs filesystem info /mnt/test
Path: /mnt/test
Max ID: 4
UUID: 1c7e4ba6-aebc-4b39-90ef-c61315fb74d1

Num devices: 3
  Dev ID: 2
  UUID: cdbda186-735e-49cd-babc-e84fffdb4105
  Bytes used: 511705088
  Total bytes: 1667235840
  Path: /dev/loop1
  Dev ID: 3
  UUID: a4cebf4e-f760-49a7-b960-142b2c14d9e6
  Bytes used: 0
  Total bytes: 1111490560
  Path: /dev/loop2
  Dev ID: 4
  UUID: 61bd5825-f86e-4708-8a5b-f48764b5c3a5
  Bytes used: 0
  Total bytes: 1111490560
  Path: /dev/loop3

I make that because it is not so trivial to get these information otherwise.

To get the information, I made public and used: scrub_device_info() and 
scrub_fs_info(). So, I moved the functions to the file utils.c changing 
scrub_ to get_. I was inspired by a patch of Stefan Behrens.

Next enhancements:
- remove the root privileges to launch the command (require change in
kernel space)
- show also the label of the filesystem (same as above)

Please review; as usual, comments are welcome.

You can pull the changes from the reposiotry
	http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch 
	filesystem-info

BR
G.Baroncelli

 Makefile          |    8 +++---
 cmds-filesystem.c |   59 ++++++++++++++++++++++++++++++++++++++++++++
 cmds-scrub.c      |   72 +-----------------------------------------------------
 man/btrfs.8.in    |    8 ++++++
 utils.c           |   68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 utils.h           |    4 +++
 6 files changed, 145 insertions(+), 74 deletions(-)

[PATCH 1/3] Btrfs-progs: make two utility functions globally available

[Goffredo Baroncelli]

This patch is ispired by a Stefan Behrens one.
---
 Makefile     |    8 +++----
 cmds-scrub.c |   72 ++--------------------------------------------------------
 utils.c      |   68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 utils.h      |    4 ++++
 4 files changed, 78 insertions(+), 74 deletions(-)

diff --git a/Makefile b/Makefile
index 79818e6..0915021 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ CFLAGS = -g -O0
 objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 	  root-tree.o dir-item.o file-item.o inode-item.o \
 	  inode-map.o crc32c.o rbtree.o extent-cache.o extent_io.o \
-	  volumes.o utils.o btrfs-list.o btrfslabel.o repair.o
+	  volumes.o utils.o btrfs-list.o btrfslabel.o repair.o common.o
 cmds_objects = cmds-subvolume.o cmds-filesystem.o cmds-device.o cmds-scrub.o \
 	       cmds-inspect.o cmds-balance.o
 
@@ -39,8 +39,8 @@ all: version $(progs) manpages
 version:
 	bash version.sh
 
-btrfs: $(objects) btrfs.o help.o common.o $(cmds_objects)
-	$(CC) $(CFLAGS) -o btrfs btrfs.o help.o common.o $(cmds_objects) \
+btrfs: $(objects) btrfs.o help.o $(cmds_objects)
+	$(CC) $(CFLAGS) -o btrfs btrfs.o help.o $(cmds_objects) \
 		$(objects) $(LDFLAGS) $(LIBS) -lpthread
 
 calc-size: $(objects) calc-size.o
@@ -52,7 +52,7 @@ btrfs-find-root: $(objects) find-root.o
 btrfs-restore: $(objects) restore.o
 	gcc $(CFLAGS) -o btrfs-restore restore.o $(objects) $(LDFLAGS) $(LIBS) $(RESTORE_LIBS)
 
-btrfsctl: $(objects) btrfsctl.o
+btrfsctl: $(objects) btrfsctl.o 
 	$(CC) $(CFLAGS) -o btrfsctl btrfsctl.o $(objects) $(LDFLAGS) $(LIBS)
 
 btrfs-vol: $(objects) btrfs-vol.o
diff --git a/cmds-scrub.c b/cmds-scrub.c
index c4503f4..37a9890 100644
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -967,74 +967,6 @@ static struct scrub_file_record *last_dev_scrub(
 	return NULL;
 }
 
-static int scrub_device_info(int fd, u64 devid,
-			     struct btrfs_ioctl_dev_info_args *di_args)
-{
-	int ret;
-
-	di_args->devid = devid;
-	memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
-
-	ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
-	return ret ? -errno : 0;
-}
-
-static int scrub_fs_info(int fd, char *path,
-				struct btrfs_ioctl_fs_info_args *fi_args,
-				struct btrfs_ioctl_dev_info_args **di_ret)
-{
-	int ret = 0;
-	int ndevs = 0;
-	int i = 1;
-	struct btrfs_fs_devices *fs_devices_mnt = NULL;
-	struct btrfs_ioctl_dev_info_args *di_args;
-	char mp[BTRFS_PATH_NAME_MAX + 1];
-
-	memset(fi_args, 0, sizeof(*fi_args));
-
-	ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
-	if (ret && errno == EINVAL) {
-		/* path is no mounted btrfs. try if it's a device */
-		ret = check_mounted_where(fd, path, mp, sizeof(mp),
-						&fs_devices_mnt);
-		if (!ret)
-			return -EINVAL;
-		if (ret < 0)
-			return ret;
-		fi_args->num_devices = 1;
-		fi_args->max_id = fs_devices_mnt->latest_devid;
-		i = fs_devices_mnt->latest_devid;
-		memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
-		close(fd);
-		fd = open_file_or_dir(mp);
-		if (fd < 0)
-			return -errno;
-	} else if (ret) {
-		return -errno;
-	}
-
-	if (!fi_args->num_devices)
-		return 0;
-
-	di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
-	if (!di_args)
-		return -errno;
-
-	for (; i <= fi_args->max_id; ++i) {
-		BUG_ON(ndevs >= fi_args->num_devices);
-		ret = scrub_device_info(fd, i, &di_args[ndevs]);
-		if (ret == -ENODEV)
-			continue;
-		if (ret)
-			return ret;
-		++ndevs;
-	}
-
-	BUG_ON(ndevs == 0);
-
-	return 0;
-}
-
 int mkdir_p(char *path)
 {
 	int i;
@@ -1155,7 +1087,7 @@ static int scrub_start(int argc, char **argv, int resume)
 		return 12;
 	}
 
-	ret = scrub_fs_info(fdmnt, path, &fi_args, &di_args);
+	ret = get_fs_info(fdmnt, path, &fi_args, &di_args);
 	if (ret) {
 		ERR(!do_quiet, "ERROR: getting dev info for scrub failed: "
 		    "%s\n", strerror(-ret));
@@ -1621,7 +1553,7 @@ static int cmd_scrub_status(int argc, char **argv)
 		return 12;
 	}
 
-	ret = scrub_fs_info(fdmnt, path, &fi_args, &di_args);
+	ret = get_fs_info(fdmnt, path, &fi_args, &di_args);
 	if (ret) {
 		fprintf(stderr, "ERROR: getting dev info for scrub failed: "
 				"%s\n", strerror(-ret));
diff --git a/utils.c b/utils.c
index ee7fa1b..d916912 100644
--- a/utils.c
+++ b/utils.c
@@ -44,6 +44,7 @@
 #include "utils.h"
 #include "volumes.h"
 #include "ioctl.h"
+#include "commands.h"
 
 #ifdef __CHECKER__
 #define BLKGETSIZE64 0
@@ -1206,3 +1207,70 @@ scan_again:
 	return 0;
 }
 
+int scrub_device_info(int fd, u64 devid,
+			     struct btrfs_ioctl_dev_info_args *di_args)
+{
+	int ret;
+
+	di_args->devid = devid;
+	memset(&di_args->uuid, '\0', sizeof(di_args->uuid));
+
+	ret = ioctl(fd, BTRFS_IOC_DEV_INFO, di_args);
+	return ret ? -errno : 0;
+}
+
+int get_fs_info(int fd, char *path,
+				struct btrfs_ioctl_fs_info_args *fi_args,
+				struct btrfs_ioctl_dev_info_args **di_ret)
+{
+	int ret = 0;
+	int ndevs = 0;
+	int i = 1;
+	struct btrfs_fs_devices *fs_devices_mnt = NULL;
+	struct btrfs_ioctl_dev_info_args *di_args;
+	char mp[BTRFS_PATH_NAME_MAX + 1];
+
+	memset(fi_args, 0, sizeof(*fi_args));
+
+	ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
+	if (ret && errno == EINVAL) {
+		/* path is no mounted btrfs. try if it's a device */
+		ret = check_mounted_where(fd, path, mp, sizeof(mp),
+						&fs_devices_mnt);
+		if (!ret)
+			return -EINVAL;
+		if (ret < 0)
+			return ret;
+		fi_args->num_devices = 1;
+		fi_args->max_id = fs_devices_mnt->latest_devid;
+		i = fs_devices_mnt->latest_devid;
+		memcpy(fi_args->fsid, fs_devices_mnt->fsid, BTRFS_FSID_SIZE);
+		close(fd);
+		fd = open_file_or_dir(mp);
+		if (fd < 0)
+			return -errno;
+	} else if (ret) {
+		return -errno;
+	}
+
+	if (!fi_args->num_devices)
+		return 0;
+
+	di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
+	if (!di_args)
+		return -errno;
+
+	for (; i <= fi_args->max_id; ++i) {
+		BUG_ON(ndevs >= fi_args->num_devices);
+		ret = scrub_device_info(fd, i, &di_args[ndevs]);
+		if (ret == -ENODEV)
+			continue;
+		if (ret)
+			return ret;
+		++ndevs;
+	}
+
+	BUG_ON(ndevs == 0);
+
+	return 0;
+}
diff --git a/utils.h b/utils.h
index c5f55e1..01220a2 100644
--- a/utils.h
+++ b/utils.h
@@ -46,4 +46,8 @@ int check_label(char *input);
 int get_mountpt(char *dev, char *mntpt, size_t size);
 
 int btrfs_scan_block_devices(int run_ioctl);
+int get_device_info(int fd, u64 devid,
+		    struct btrfs_ioctl_dev_info_args *di_args);
+int get_fs_info(int fd, char *path, struct btrfs_ioctl_fs_info_args *fi_args,
+		struct btrfs_ioctl_dev_info_args **di_ret);
 #endif
-- 
1.7.10

[PATCH 2/3] Add btrfs filesystem info command.

[Goffredo Baroncelli]

Add btrfs filesystem info command, which is capable to show some
btrfs filesystem information.
---
 cmds-filesystem.c |   59 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index 1f53d1c..9acc715 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -519,6 +519,64 @@ static int cmd_label(int argc, char **argv)
 		return get_label(argv[1]);
 }
 
+static const char * const cmd_info_usage[] = {
+	"btrfs filesystem info <path>",
+	"Get filesystem information",
+	NULL
+};
+
+static int cmd_info(int argc, char **argv){
+
+	struct btrfs_ioctl_fs_info_args 	fi_args;
+	struct btrfs_ioctl_dev_info_args 	*di_ret=NULL;
+	int    					ret,i;
+	char					uuidbuf[37];
+	int					fd;
+
+	if( argc != 2){
+		fprintf(stderr, "ERROR: missing argument\n");
+		return 102;
+	}
+
+	fd = open_file_or_dir(argv[1]);
+	if( fd < 0 ){
+		fprintf(stderr, "ERROR: cannot open '%s'\n", argv[1]);
+		return 103;
+	}
+
+	ret = get_fs_info(fd, argv[1], &fi_args, &di_ret);
+	if( ret ){
+		int e = errno;
+		fprintf(stderr, "ERROR: cannot get information about '%s'\n",
+			argv[1]);
+		fprintf(stderr, "ERROR: errno=%d, error=%s\n",
+			e, strerror(e) );
+		close(fd);
+		if(di_ret != NULL )
+			free(di_ret);
+		return 104;
+	}
+
+	printf("Path: %s\n",argv[1]);
+	printf("Max ID: %llu\n", fi_args.max_id);
+	uuid_unparse(fi_args.fsid, uuidbuf);
+	printf("UUID: %s\n", uuidbuf);
+
+	printf("\nNum devices: %llu\n", fi_args.num_devices);
+	for( i = 0 ; i < fi_args.num_devices ; i++ ){
+		printf("  Dev ID: %llu\n", di_ret[i].devid);
+		uuid_unparse(di_ret[i].uuid, uuidbuf);
+		printf("  UUID: %s\n", uuidbuf);
+		printf("  Bytes used: %llu\n", di_ret[i].bytes_used );
+		printf("  Total bytes: %llu\n", di_ret[i].total_bytes );
+		printf("  Path: %s\n", di_ret[i].path);
+	}
+
+	close(fd);
+	free(di_ret);
+	return 0;
+}
+
 const struct cmd_group filesystem_cmd_group = {
 	filesystem_cmd_group_usage, NULL, {
 		{ "df", cmd_df, cmd_df_usage, NULL, 0 },
@@ -528,6 +586,7 @@ const struct cmd_group filesystem_cmd_group = {
 		{ "balance", cmd_balance, NULL, &balance_cmd_group, 1 },
 		{ "resize", cmd_resize, cmd_resize_usage, NULL, 0 },
 		{ "label", cmd_label, cmd_label_usage, NULL, 0 },
+		{ "info", cmd_info, cmd_info_usage, NULL, 0 },
 		{ 0, 0, 0, 0, 0 },
 	}
 };
-- 
1.7.10

[PATCH 3/3] Add btrfs filesystem info man page.

[Goffredo Baroncelli]

Update the man page to document the "btrfs filesystem info <path>"
command.
---
 man/btrfs.8.in |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index be478e0..6d96bf7 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -25,6 +25,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem defrag\fP\fI [options] <file>|<dir> [<file>|<dir>...]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem info\fP\fI <path>\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -154,6 +156,12 @@ The start position and the number of bytes to deframention can be specified by \
 NOTE: defragmenting with kernels up to 2.6.37 will unlink COW-ed copies of data, don't 
 use it if you use snapshots, have de-duplicated your data or made copies with 
 \fBcp --reflink\fP.
+.TP
+
+\fBfilesystem info\fP \fI<path>\fR
+Get filesystem info.
+.TP
+
 \fBsubvolume find-new\fR\fI <subvolume> <last_gen>\fR
 List the recently modified files in a subvolume, after \fI<last_gen>\fR ID.
 .TP
-- 
1.7.10

Re: [PATCH 3/3] Add btrfs filesystem info man page.

[Jérôme Poulin]

What kind of "info" does it give? This is really unhelpful in a man
page, it just tells the obvious.

On Fri, Jun 8, 2012 at 3:12 PM, Goffredo Baroncelli <kreijack@inwind.it> wrote:
>
> Update the man page to document the "btrfs filesystem info <path>"
> command.
> ---
>  man/btrfs.8.in |    8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/man/btrfs.8.in b/man/btrfs.8.in
> index be478e0..6d96bf7 100644
> --- a/man/btrfs.8.in
> +++ b/man/btrfs.8.in
> @@ -25,6 +25,8 @@ btrfs \- control a btrfs filesystem
>  .PP
>  \fBbtrfs\fP \fBfilesystem defrag\fP\fI [options] <file>|<dir> [<file>|<dir>...]\fP
>  .PP
> +\fBbtrfs\fP \fBfilesystem info\fP\fI <path>\fP
> +.PP
>  \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
>  .PP
>  \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
> @@ -154,6 +156,12 @@ The start position and the number of bytes to deframention can be specified by \
>  NOTE: defragmenting with kernels up to 2.6.37 will unlink COW-ed copies of data, don't
>  use it if you use snapshots, have de-duplicated your data or made copies with
>  \fBcp --reflink\fP.
> +.TP
> +
> +\fBfilesystem info\fP \fI<path>\fR
> +Get filesystem info.
> +.TP
> +
>  \fBsubvolume find-new\fR\fI <subvolume> <last_gen>\fR
>  List the recently modified files in a subvolume, after \fI<last_gen>\fR ID.
>  .TP
> --
> 1.7.10
>
> --
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> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 3/3] Add btrfs filesystem info man page.

[Goffredo Baroncelli]

On 06/08/2012 09:21 PM, Jérôme Poulin wrote:
> What kind of "info" does it give? This is really unhelpful in a man
> page, it just tells the obvious.

Definitely, this is one of the point of this patch to improve.

> 
> On Fri, Jun 8, 2012 at 3:12 PM, Goffredo Baroncelli <kreijack@inwind.it> wrote:
>>
>> Update the man page to document the "btrfs filesystem info <path>"
>> command.
>> ---
>>  man/btrfs.8.in |    8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/man/btrfs.8.in b/man/btrfs.8.in
>> index be478e0..6d96bf7 100644
>> --- a/man/btrfs.8.in
>> +++ b/man/btrfs.8.in
>> @@ -25,6 +25,8 @@ btrfs \- control a btrfs filesystem
>>  .PP
>>  \fBbtrfs\fP \fBfilesystem defrag\fP\fI [options] <file>|<dir> [<file>|<dir>...]\fP
>>  .PP
>> +\fBbtrfs\fP \fBfilesystem info\fP\fI <path>\fP
>> +.PP
>>  \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
>>  .PP
>>  \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
>> @@ -154,6 +156,12 @@ The start position and the number of bytes to deframention can be specified by \
>>  NOTE: defragmenting with kernels up to 2.6.37 will unlink COW-ed copies of data, don't
>>  use it if you use snapshots, have de-duplicated your data or made copies with
>>  \fBcp --reflink\fP.
>> +.TP
>> +
>> +\fBfilesystem info\fP \fI<path>\fR
>> +Get filesystem info.
>> +.TP
>> +
>>  \fBsubvolume find-new\fR\fI <subvolume> <last_gen>\fR
>>  List the recently modified files in a subvolume, after \fI<last_gen>\fR ID.
>>  .TP
>> --
>> 1.7.10
>>
>> --
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>> the body of a message to majordomo@vger.kernel.org
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> --
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> .
>