[PATCH 2/2] Update help page

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..3215216 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem disk-usage\fP\fI [-s][-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem disk-usage\fP [-s][-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Don't show the summary section
+
+\fB-d\fP Don't show the detail section
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem disk-usage\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem disk-usage\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..ed20448 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-s][-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-s][-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Don't show the summary section
+
+\fB-d\fP Don't show the detail section
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH][BTRFS-PROGS][V2] btrfs filesystem df

[Goffredo Baroncelli]

>From the man page (see 2nd patch):

[...]
The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
[...]

$ ./btrfs filesystem df --help
usage: btrfs filesystem disk-usage [-d|-s][-k] <path> [<path>..]

    Show space usage information for a mount point(s).

    -k  Set KB (1024 bytes) as unit
    -s  Show the summary section only
    -d  Show the detail section only

$ ./btrfs filesystem df /
Path: /
Summary:
  Disk_size:                 72.57GB
  Disk_allocated:            25.10GB
  Disk_unallocated:          47.48GB
  Logical_size:              23.06GB
  Used:                      11.01GB
  Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
  Data_to_disk_ratio:           92 %

Details:
  Chunk-type  Mode      Chunk_size Logical_size        Used
  Data        Single       21.01GB      21.01GB     10.34GB
  System      DUP          80.00MB      40.00MB      4.00KB
  System      Single        4.00MB       4.00MB        0.00
  Metadata    DUP           4.00GB       2.00GB    686.93MB
  Metadata    Single        8.00MB       8.00MB        0.00

Where:
        Disk_size                       -> sum of sizes of teh disks
        Disk_allocated                  -> sum of chunk sizes
        Disk_unallocated                -> Disk_size - Disk_allocated
        Logical_size                    -> sum of logical area sizes
        Used                            -> logical area used
        Free_(Estimated)                -> on the basis of allocated
                                           chunk, an estrapolation of
                                           the free space
        Data_to_disk_ratio              -> ration between the space occuped
                                           by a chunk and the real space
                                           available ( due to duplication
                                           and/or RAID level)
        Chunk_type                      -> kind of chunk
        Mode                            -> allocation policy of a chunk
        Chunk_size                      -> area of disk(s) occuped by the
                                           chunk (see it as raw space used)
        Logical_size                    -> logical area size of the chunk
        Used                            -> portion of the logical area
                                           used by the filesystem



You can pull this change from
   http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
   disk_free

Please pull.

BR
Goffredo Baroncelli

Changelog:
V0->V1          Change the name of command from disk-usage to df
V1->V2		Uses getopt(); replace "-" with "_"; change the behaviour
		of the switches '-s' and '-d'.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>

[PATCH 1/2] Update btrfs filesystem df command

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

The  command  btrfs  filesystem  df is used to query the
status of the chunks, how many space on the disk(s) are used  by
the  chunks,  how many space are available in the chunks, and an
estimation of the free space of the filesystem.
---
 cmds-filesystem.c |  284 ++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 235 insertions(+), 49 deletions(-)

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index b1457de..2701904 100644
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <uuid/uuid.h>
 #include <ctype.h>
+#include <sys/vfs.h>
 
 #include "kerncompat.h"
 #include "ctree.h"
@@ -39,25 +40,55 @@ static const char * const filesystem_cmd_group_usage[] = {
 	NULL
 };
 
-static const char * const cmd_df_usage[] = {
-	"btrfs filesystem df <path>",
-	"Show space usage information for a mount point",
-	NULL
-};
+static u64 disk_size( char *path){
+	struct statfs	sfs;
+
+	if( statfs(path, &sfs) < 0 )
+		return 0;
+	else
+		return sfs.f_bsize * sfs.f_blocks;
+
+}
+
+static void print_string(char *s, int w)
+{
+	int	i;
+
+	printf("%s", s);
+	for( i = strlen(s) ; i < w ; i++ ) 
+		putchar(' ');
+}
+
+#define DF_SHOW_SUMMARY 	(1<<1)
+#define DF_SHOW_DETAIL		(1<<2)
+#define DF_HUMAN_UNIT		(1<<3)
+
+static void pretty_sizes_r(u64 size, int w, int mode)
+{
+	if( mode & DF_HUMAN_UNIT ){
+		char *s = pretty_sizes(size);
+		printf("%*s", w, s);
+		free(s);
+	} else {
+		printf("%*llu", w, size/1024);
+
+	}
+}
 
-static int cmd_df(int argc, char **argv)
+static int _cmd_disk_free(char *path, int mode)
 {
 	struct btrfs_ioctl_space_args *sargs;
 	u64 count = 0, i;
 	int ret;
 	int fd;
-	int e;
-	char *path;
-
-	if (check_argc_exact(argc, 2))
-		usage(cmd_df_usage);
-
-	path = argv[1];
+	int e, width;
+	u64  total_disk;		/* filesystem size == sum of
+					   disks sizes */
+	u64  total_chunks;		/* sum of chunks sizes on disk(s) */
+	u64  total_used;		/* logical space used */
+	u64  total_free;		/* logical space un-used */
+	double K;
+	
 
 	fd = open_file_or_dir(path);
 	if (fd < 0) {
@@ -103,56 +134,211 @@ static int cmd_df(int argc, char **argv)
 		return ret;
 	}
 
-	for (i = 0; i < sargs->total_spaces; i++) {
-		char description[80];
-		char *total_bytes;
-		char *used_bytes;
-		int written = 0;
-		u64 flags = sargs->spaces[i].flags;
+	total_disk = disk_size(path);
+	e = errno;
+	if( total_disk == 0 ){
+		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
+			path, strerror(e));
+		close(fd);
+		free(sargs);
+		return 19;
+	}
+		
+	total_chunks = total_used = total_free = 0;
 
-		memset(description, 0, 80);
+	for (i = 0; i < sargs->total_spaces; i++) {
+		int  ratio=1;
+		u64  allocated;
 
-		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;
-		}
+		u64 flags = sargs->spaces[i].flags;
 
 		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
-			snprintf(description+written, 8, "%s", ", RAID0");
-			written += 7;
+			ratio=1;
 		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
-			snprintf(description+written, 8, "%s", ", RAID1");
-			written += 7;
+			ratio=2;
 		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
-			snprintf(description+written, 6, "%s", ", DUP");
-			written += 5;
+			ratio=2;
 		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
-			snprintf(description+written, 9, "%s", ", RAID10");
-			written += 8;
+			ratio=2;
+		} else {
+			ratio=1;
 		}
 
-		total_bytes = pretty_sizes(sargs->spaces[i].total_bytes);
-		used_bytes = pretty_sizes(sargs->spaces[i].used_bytes);
-		printf("%s: total=%s, used=%s\n", description, total_bytes,
-		       used_bytes);
+		allocated = sargs->spaces[i].total_bytes * ratio;
+
+		total_chunks += allocated;
+		total_used += sargs->spaces[i].used_bytes;
+		total_free += (sargs->spaces[i].total_bytes - 
+					sargs->spaces[i].used_bytes);
+
+	}
+	K = ((double)total_used + (double)total_free) /
+	                (double)total_chunks;
+
+	if( mode & DF_HUMAN_UNIT )
+		width = 12;
+	else
+		width = 18;
+
+	printf("Path: %s\n", path);
+	if( mode & DF_SHOW_SUMMARY ){
+		printf("Summary:\n");
+		printf("  Disk_size:\t\t");
+		pretty_sizes_r(total_disk, width, mode);
+		printf("\n  Disk_allocated:\t");
+		pretty_sizes_r(total_chunks, width, mode);
+		printf("\n  Disk_unallocated:\t"); 
+		pretty_sizes_r(total_disk-total_chunks, width, mode);
+		printf("\n  Logical_size:\t\t"); 
+		pretty_sizes_r(total_used+total_free, width, mode);
+		printf("\n  Used:\t\t\t"); 
+		pretty_sizes_r(total_used, width, mode);
+		printf("\n  Free_(Estimated):\t");
+		pretty_sizes_r((u64)(K*total_disk-total_used), width, mode);
+		printf("\t(Max: ");
+		pretty_sizes_r(total_disk-total_chunks+total_free, 
+				0, mode );
+		printf(", Min: ");
+		pretty_sizes_r((total_disk-total_chunks)/2+total_free, 
+				0, mode );
+		printf(")\n  Data_to_disk_ratio:\t%*.0f %%\n",
+			width-2, K*100);
+	}
+
+	if( ( mode & DF_SHOW_DETAIL ) && ( mode & DF_SHOW_SUMMARY ) )
+		printf("\n");
+
+	if( mode & DF_SHOW_DETAIL ){
+		/* Remember: the terminals have maximum 80 columns
+		   do not believe to who says otherwise */
+		printf("Details:\n");
+		printf("  %-12s%-8s%*s%*s%*s\n",
+			"Chunk_type", 
+			"Mode",
+			width, "Chunk_size", 
+			width+1, "Logical_size", 
+			width, "Used"
+		);
+
+		for (i = 0; i < sargs->total_spaces; i++) {
+			char *description="";
+			int  ratio=1;
+			char *r_mode;
+			u64 allocated;
+
+			u64 flags = sargs->spaces[i].flags;
+
+			if (flags & BTRFS_BLOCK_GROUP_DATA) {
+				if (flags & BTRFS_BLOCK_GROUP_METADATA){
+					description = "Data+M.data";
+				} else {
+					description = "Data";
+				}
+			} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+				description = "System";
+			} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
+				description = "Metadata";
+			}
+
+			if (flags & BTRFS_BLOCK_GROUP_RAID0) {
+				r_mode = "RAID0";
+				ratio=1;
+			} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
+				r_mode = "RAID1";
+				ratio=2;
+			} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
+				r_mode = "DUP";
+				ratio=2;
+			} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
+				r_mode = "RAID10";
+				ratio=2;
+			} else {
+				r_mode = "Single";
+				ratio=1;
+			}
+
+			allocated = sargs->spaces[i].total_bytes * ratio;
+
+			printf("  ");
+			print_string(description,12);
+			print_string(r_mode, 8);
+			pretty_sizes_r(allocated, width, mode);
+			pretty_sizes_r(sargs->spaces[i].total_bytes ,
+				    width+1, mode);
+	
+			pretty_sizes_r(sargs->spaces[i].used_bytes, 
+						width, mode);
+			printf("\n");
+
+		}
 	}
 	free(sargs);
 
 	return 0;
 }
 
+static const char * const cmd_disk_free_usage[] = {
+	"btrfs filesystem df [-d|-s][-k] <path> [<path>..]",
+	"Show space usage information for a mount point(s).",
+	"",
+	"-k\tSet KB (1024 bytes) as unit",
+	"-s\tShow the summary section only",
+	"-d\tShow the detail section only",
+	NULL
+};
+
+static int cmd_disk_free(int argc, char **argv)
+{
+
+	int 	flags=DF_SHOW_SUMMARY|DF_SHOW_DETAIL|DF_HUMAN_UNIT;
+	int	i, more_than_one=0;
+
+	optind = 1;
+	while(1){
+		char	c = getopt(argc, argv, "dsk");
+		if(c<0)
+			break;
+		switch(c){
+			case 'd':
+				flags &= ~DF_SHOW_SUMMARY;
+				break;
+			case 's':
+				flags &= ~DF_SHOW_DETAIL;
+				break;
+			case 'k':
+				flags &= ~DF_HUMAN_UNIT;
+				break;
+			default:
+				usage(cmd_disk_free_usage);
+		}
+	}
+
+	if( !(flags & (DF_SHOW_SUMMARY|DF_SHOW_DETAIL)) ){
+		fprintf(stderr, "btrfs filesystem df: it is not possible to specify -s AND -d\n");
+		usage(cmd_disk_free_usage);
+		return 20;
+	}
+
+	if (check_argc_min(argc - optind, 1)){
+		usage(cmd_disk_free_usage);
+		return 21;
+	}
+
+	for(i=optind; i< argc ; i++){
+		int r;
+		if(more_than_one)
+			printf("\n");
+		r = _cmd_disk_free(argv[i], flags);
+		if( r ) return r;
+		more_than_one=1;
+
+	}
+
+	return 0;
+}	
+	
+
+	
 static int uuid_search(struct btrfs_fs_devices *fs_devices, char *search)
 {
 	char uuidbuf[37];
@@ -529,7 +715,7 @@ static int cmd_label(int argc, char **argv)
 
 const struct cmd_group filesystem_cmd_group = {
 	filesystem_cmd_group_usage, NULL, {
-		{ "df", cmd_df, cmd_df_usage, NULL, 0 },
+		{ "df", cmd_disk_free, cmd_disk_free_usage, NULL, 0 },
 		{ "show", cmd_show, cmd_show_usage, NULL, 0 },
 		{ "sync", cmd_sync, cmd_sync_usage, NULL, 0 },
 		{ "defragment", cmd_defrag, cmd_defrag_usage, NULL, 0 },
-- 
1.7.10.4

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |   94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..0db588f 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-s|-d][-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,98 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-s|-d][-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fB-s\fP Show the summary section only
+
+\fB-d\fP Show the detail section only
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+A chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space two time greater than the logical one. Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Because some files (the small ones) are stored in the 
+metadata chunks the computation of the \fIfree space\fP and \fIused space\fP
+is complex: depending by the file size different allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP Disk\ size 
+the total size of the disks which compose the filesystem.
+
+.IP Disk\ allocated 
+the size of the area of the disks used by the chunks.
+
+.IP Disk\ unallocated 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP Logical\ size 
+the available logical space of chunk. 
+
+.IP Used 
+the portion of the logical space used by the file and metadata.
+
+.IP Free\ (estimated) 
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP Data\ to\ disk\ ratio
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP Mode
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

Re: [PATCH][BTRFS-PROGS][V2] btrfs filesystem df

[David Sterba]

On Wed, Oct 03, 2012 at 07:22:30PM +0200, Goffredo Baroncelli wrote:
> $ ./btrfs filesystem df /
> Path: /
> Summary:
>   Disk_size:                 72.57GB
>   Disk_allocated:            25.10GB
>   Disk_unallocated:          47.48GB
>   Logical_size:              23.06GB
>   Used:                      11.01GB
>   Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
>   Data_to_disk_ratio:           92 %
> 
> Details:
>   Chunk-type  Mode      Chunk_size Logical_size        Used
>   Data        Single       21.01GB      21.01GB     10.34GB
>   System      DUP          80.00MB      40.00MB      4.00KB
>   System      Single        4.00MB       4.00MB        0.00
>   Metadata    DUP           4.00GB       2.00GB    686.93MB
>   Metadata    Single        8.00MB       8.00MB        0.00

Please snip the following help text from basic output, eg. when I'm
running the 'df' command before/after some actions from scripts, this
is unnecessary.

> Where:
>         Disk_size                       -> sum of sizes of teh disks
>         Disk_allocated                  -> sum of chunk sizes
>         Disk_unallocated                -> Disk_size - Disk_allocated
>         Logical_size                    -> sum of logical area sizes
>         Used                            -> logical area used
>         Free_(Estimated)                -> on the basis of allocated
>                                            chunk, an estrapolation of
>                                            the free space
>         Data_to_disk_ratio              -> ration between the space occuped
>                                            by a chunk and the real space
>                                            available ( due to duplication
>                                            and/or RAID level)
>         Chunk_type                      -> kind of chunk
>         Mode                            -> allocation policy of a chunk
>         Chunk_size                      -> area of disk(s) occuped by the
>                                            chunk (see it as raw space used)
>         Logical_size                    -> logical area size of the chunk
>         Used                            -> portion of the logical area
>                                            used by the filesystem


david

Re: [PATCH][BTRFS-PROGS][V2] btrfs filesystem df

[Goffredo Baroncelli]

On 10/03/2012 09:32 PM, David Sterba wrote:
> On Wed, Oct 03, 2012 at 07:22:30PM +0200, Goffredo Baroncelli wrote:
>> $ ./btrfs filesystem df /
>> Path: /
>> Summary:
>>    Disk_size:                 72.57GB
>>    Disk_allocated:            25.10GB
>>    Disk_unallocated:          47.48GB
>>    Logical_size:              23.06GB
>>    Used:                      11.01GB
>>    Free_(Estimated):          55.66GB    (Max: 59.52GB, Min: 35.78GB)
>>    Data_to_disk_ratio:           92 %
>>
>> Details:
>>    Chunk-type  Mode      Chunk_size Logical_size        Used
>>    Data        Single       21.01GB      21.01GB     10.34GB
>>    System      DUP          80.00MB      40.00MB      4.00KB
>>    System      Single        4.00MB       4.00MB        0.00
>>    Metadata    DUP           4.00GB       2.00GB    686.93MB
>>    Metadata    Single        8.00MB       8.00MB        0.00
>
> Please snip the following help text from basic output, eg. when I'm
> running the 'df' command before/after some actions from scripts, this
> is unnecessary.

Hi David,

the output of the program ends with the "Metadata Single....". What you 
called "Help text" is a short description in the email.

BR
Goffredo


>
>> Where:
>>          Disk_size                       ->  sum of sizes of teh disks
>>          Disk_allocated                  ->  sum of chunk sizes
>>          Disk_unallocated                ->  Disk_size - Disk_allocated
>>          Logical_size                    ->  sum of logical area sizes
>>          Used                            ->  logical area used
>>          Free_(Estimated)                ->  on the basis of allocated
>>                                             chunk, an estrapolation of
>>                                             the free space
>>          Data_to_disk_ratio              ->  ration between the space occuped
>>                                             by a chunk and the real space
>>                                             available ( due to duplication
>>                                             and/or RAID level)
>>          Chunk_type                      ->  kind of chunk
>>          Mode                            ->  allocation policy of a chunk
>>          Chunk_size                      ->  area of disk(s) occuped by the
>>                                             chunk (see it as raw space used)
>>          Logical_size                    ->  logical area size of the chunk
>>          Used                            ->  portion of the logical area
>>                                             used by the filesystem
>
>
> david
>

Re: [PATCH 1/2] Update btrfs filesystem df command

[Ilya Dryomov]

On Wed, Oct 03, 2012 at 07:22:31PM +0200, Goffredo Baroncelli wrote:
> From: Goffredo Baroncelli <kreijack@inwind.it>
> 
> The  command  btrfs  filesystem  df is used to query the
> status of the chunks, how many space on the disk(s) are used  by
> the  chunks,  how many space are available in the chunks, and an
> estimation of the free space of the filesystem.
> ---
>  cmds-filesystem.c |  284 ++++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 235 insertions(+), 49 deletions(-)
> 
> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
> index b1457de..2701904 100644
> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> @@ -22,6 +22,7 @@
>  #include <errno.h>
>  #include <uuid/uuid.h>
>  #include <ctype.h>
> +#include <sys/vfs.h>
>  
>  #include "kerncompat.h"
>  #include "ctree.h"
> @@ -39,25 +40,55 @@ static const char * const filesystem_cmd_group_usage[] = {
>  	NULL
>  };
>  
> -static const char * const cmd_df_usage[] = {
> -	"btrfs filesystem df <path>",
> -	"Show space usage information for a mount point",
> -	NULL
> -};
> +static u64 disk_size( char *path){
> +	struct statfs	sfs;
> +
> +	if( statfs(path, &sfs) < 0 )
> +		return 0;
> +	else
> +		return sfs.f_bsize * sfs.f_blocks;
> +
> +}
> +
> +static void print_string(char *s, int w)
> +{
> +	int	i;
> +
> +	printf("%s", s);
> +	for( i = strlen(s) ; i < w ; i++ ) 
> +		putchar(' ');
> +}
> +
> +#define DF_SHOW_SUMMARY 	(1<<1)
> +#define DF_SHOW_DETAIL		(1<<2)
> +#define DF_HUMAN_UNIT		(1<<3)
> +
> +static void pretty_sizes_r(u64 size, int w, int mode)
> +{
> +	if( mode & DF_HUMAN_UNIT ){
> +		char *s = pretty_sizes(size);
> +		printf("%*s", w, s);
> +		free(s);
> +	} else {
> +		printf("%*llu", w, size/1024);
> +
> +	}
> +}
>  
> -static int cmd_df(int argc, char **argv)
> +static int _cmd_disk_free(char *path, int mode)
>  {
>  	struct btrfs_ioctl_space_args *sargs;
>  	u64 count = 0, i;
>  	int ret;
>  	int fd;
> -	int e;
> -	char *path;
> -
> -	if (check_argc_exact(argc, 2))
> -		usage(cmd_df_usage);
> -
> -	path = argv[1];
> +	int e, width;
> +	u64  total_disk;		/* filesystem size == sum of
> +					   disks sizes */
> +	u64  total_chunks;		/* sum of chunks sizes on disk(s) */
> +	u64  total_used;		/* logical space used */
> +	u64  total_free;		/* logical space un-used */
> +	double K;
> +	
>  
>  	fd = open_file_or_dir(path);
>  	if (fd < 0) {
> @@ -103,56 +134,211 @@ static int cmd_df(int argc, char **argv)
>  		return ret;
>  	}
>  
> -	for (i = 0; i < sargs->total_spaces; i++) {
> -		char description[80];
> -		char *total_bytes;
> -		char *used_bytes;
> -		int written = 0;
> -		u64 flags = sargs->spaces[i].flags;
> +	total_disk = disk_size(path);
> +	e = errno;
> +	if( total_disk == 0 ){
> +		fprintf(stderr, "ERROR: couldn't get space info on '%s' - %s\n",
> +			path, strerror(e));
> +		close(fd);
> +		free(sargs);
> +		return 19;
> +	}
> +		
> +	total_chunks = total_used = total_free = 0;
>  
> -		memset(description, 0, 80);
> +	for (i = 0; i < sargs->total_spaces; i++) {
> +		int  ratio=1;
> +		u64  allocated;
>  
> -		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;
> -		}
> +		u64 flags = sargs->spaces[i].flags;
>  
>  		if (flags & BTRFS_BLOCK_GROUP_RAID0) {
> -			snprintf(description+written, 8, "%s", ", RAID0");
> -			written += 7;
> +			ratio=1;
>  		} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
> -			snprintf(description+written, 8, "%s", ", RAID1");
> -			written += 7;
> +			ratio=2;
>  		} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
> -			snprintf(description+written, 6, "%s", ", DUP");
> -			written += 5;
> +			ratio=2;
>  		} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
> -			snprintf(description+written, 9, "%s", ", RAID10");
> -			written += 8;
> +			ratio=2;
> +		} else {
> +			ratio=1;
>  		}
>  
> -		total_bytes = pretty_sizes(sargs->spaces[i].total_bytes);
> -		used_bytes = pretty_sizes(sargs->spaces[i].used_bytes);
> -		printf("%s: total=%s, used=%s\n", description, total_bytes,
> -		       used_bytes);
> +		allocated = sargs->spaces[i].total_bytes * ratio;
> +
> +		total_chunks += allocated;
> +		total_used += sargs->spaces[i].used_bytes;
> +		total_free += (sargs->spaces[i].total_bytes - 
> +					sargs->spaces[i].used_bytes);
> +
> +	}
> +	K = ((double)total_used + (double)total_free) /
> +	                (double)total_chunks;
> +
> +	if( mode & DF_HUMAN_UNIT )
> +		width = 12;
> +	else
> +		width = 18;
> +
> +	printf("Path: %s\n", path);
> +	if( mode & DF_SHOW_SUMMARY ){
> +		printf("Summary:\n");
> +		printf("  Disk_size:\t\t");
> +		pretty_sizes_r(total_disk, width, mode);
> +		printf("\n  Disk_allocated:\t");
> +		pretty_sizes_r(total_chunks, width, mode);
> +		printf("\n  Disk_unallocated:\t"); 
> +		pretty_sizes_r(total_disk-total_chunks, width, mode);
> +		printf("\n  Logical_size:\t\t"); 
> +		pretty_sizes_r(total_used+total_free, width, mode);
> +		printf("\n  Used:\t\t\t"); 
> +		pretty_sizes_r(total_used, width, mode);
> +		printf("\n  Free_(Estimated):\t");
> +		pretty_sizes_r((u64)(K*total_disk-total_used), width, mode);
> +		printf("\t(Max: ");
> +		pretty_sizes_r(total_disk-total_chunks+total_free, 
> +				0, mode );
> +		printf(", Min: ");
> +		pretty_sizes_r((total_disk-total_chunks)/2+total_free, 
> +				0, mode );
> +		printf(")\n  Data_to_disk_ratio:\t%*.0f %%\n",
> +			width-2, K*100);
> +	}
> +
> +	if( ( mode & DF_SHOW_DETAIL ) && ( mode & DF_SHOW_SUMMARY ) )
> +		printf("\n");
> +
> +	if( mode & DF_SHOW_DETAIL ){
> +		/* Remember: the terminals have maximum 80 columns
> +		   do not believe to who says otherwise */
> +		printf("Details:\n");
> +		printf("  %-12s%-8s%*s%*s%*s\n",
> +			"Chunk_type", 
> +			"Mode",
> +			width, "Chunk_size", 
> +			width+1, "Logical_size", 
> +			width, "Used"
> +		);
> +
> +		for (i = 0; i < sargs->total_spaces; i++) {
> +			char *description="";
> +			int  ratio=1;
> +			char *r_mode;
> +			u64 allocated;
> +
> +			u64 flags = sargs->spaces[i].flags;
> +
> +			if (flags & BTRFS_BLOCK_GROUP_DATA) {
> +				if (flags & BTRFS_BLOCK_GROUP_METADATA){
> +					description = "Data+M.data";
> +				} else {
> +					description = "Data";
> +				}
> +			} else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
> +				description = "System";
> +			} else if (flags & BTRFS_BLOCK_GROUP_METADATA) {
> +				description = "Metadata";
> +			}
> +
> +			if (flags & BTRFS_BLOCK_GROUP_RAID0) {
> +				r_mode = "RAID0";
> +				ratio=1;
> +			} else if (flags & BTRFS_BLOCK_GROUP_RAID1) {
> +				r_mode = "RAID1";
> +				ratio=2;
> +			} else if (flags & BTRFS_BLOCK_GROUP_DUP) {
> +				r_mode = "DUP";
> +				ratio=2;
> +			} else if (flags & BTRFS_BLOCK_GROUP_RAID10) {
> +				r_mode = "RAID10";
> +				ratio=2;
> +			} else {
> +				r_mode = "Single";
> +				ratio=1;
> +			}
> +
> +			allocated = sargs->spaces[i].total_bytes * ratio;
> +
> +			printf("  ");
> +			print_string(description,12);
> +			print_string(r_mode, 8);
> +			pretty_sizes_r(allocated, width, mode);
> +			pretty_sizes_r(sargs->spaces[i].total_bytes ,
> +				    width+1, mode);
> +	
> +			pretty_sizes_r(sargs->spaces[i].used_bytes, 
> +						width, mode);
> +			printf("\n");
> +
> +		}
>  	}
>  	free(sargs);
>  
>  	return 0;
>  }
>  
> +static const char * const cmd_disk_free_usage[] = {
> +	"btrfs filesystem df [-d|-s][-k] <path> [<path>..]",
> +	"Show space usage information for a mount point(s).",
> +	"",
> +	"-k\tSet KB (1024 bytes) as unit",
> +	"-s\tShow the summary section only",
> +	"-d\tShow the detail section only",
> +	NULL
> +};
> +
> +static int cmd_disk_free(int argc, char **argv)
> +{
> +
> +	int 	flags=DF_SHOW_SUMMARY|DF_SHOW_DETAIL|DF_HUMAN_UNIT;
> +	int	i, more_than_one=0;
> +
> +	optind = 1;
> +	while(1){
> +		char	c = getopt(argc, argv, "dsk");
> +		if(c<0)
> +			break;
> +		switch(c){
> +			case 'd':
> +				flags &= ~DF_SHOW_SUMMARY;
> +				break;
> +			case 's':
> +				flags &= ~DF_SHOW_DETAIL;
> +				break;
> +			case 'k':
> +				flags &= ~DF_HUMAN_UNIT;
> +				break;
> +			default:
> +				usage(cmd_disk_free_usage);
> +		}
> +	}
> +
> +	if( !(flags & (DF_SHOW_SUMMARY|DF_SHOW_DETAIL)) ){
> +		fprintf(stderr, "btrfs filesystem df: it is not possible to specify -s AND -d\n");

This doesn't look right at all.  You are adding two switches and
specifying both of them is an error?  A little too much for a command
whose job is to do some basic math and pretty-print the result.

How about displaying just the summary by default and then adding a
*single* switch (-v or whatever) for summary+details?

Thanks,

		Ilya

Re: [PATCH 1/2] Update btrfs filesystem df command

[Hugo Mills]

[-- Attachment #1: Type: text/plain, Size: 2234 bytes --]

On Wed, Oct 03, 2012 at 11:34:00PM +0300, Ilya Dryomov wrote:
> On Wed, Oct 03, 2012 at 07:22:31PM +0200, Goffredo Baroncelli wrote:
[snip]
> > +static const char * const cmd_disk_free_usage[] = {
> > +	"btrfs filesystem df [-d|-s][-k] <path> [<path>..]",
> > +	"Show space usage information for a mount point(s).",
> > +	"",
> > +	"-k\tSet KB (1024 bytes) as unit",
> > +	"-s\tShow the summary section only",
> > +	"-d\tShow the detail section only",
> > +	NULL
> > +};
> > +
> > +static int cmd_disk_free(int argc, char **argv)
> > +{
> > +
> > +	int 	flags=DF_SHOW_SUMMARY|DF_SHOW_DETAIL|DF_HUMAN_UNIT;
> > +	int	i, more_than_one=0;
> > +
> > +	optind = 1;
> > +	while(1){
> > +		char	c = getopt(argc, argv, "dsk");
> > +		if(c<0)
> > +			break;
> > +		switch(c){
> > +			case 'd':
> > +				flags &= ~DF_SHOW_SUMMARY;
> > +				break;
> > +			case 's':
> > +				flags &= ~DF_SHOW_DETAIL;
> > +				break;
> > +			case 'k':
> > +				flags &= ~DF_HUMAN_UNIT;
> > +				break;
> > +			default:
> > +				usage(cmd_disk_free_usage);
> > +		}
> > +	}
> > +
> > +	if( !(flags & (DF_SHOW_SUMMARY|DF_SHOW_DETAIL)) ){
> > +		fprintf(stderr, "btrfs filesystem df: it is not possible to specify -s AND -d\n");
> 
> This doesn't look right at all.  You are adding two switches and
> specifying both of them is an error?  A little too much for a command
> whose job is to do some basic math and pretty-print the result.
> 
> How about displaying just the summary by default and then adding a
> *single* switch (-v or whatever) for summary+details?

   I'd prefer to see both sections by default. The reason for this is
that without both sections, people tend to get confused because they
don't know they're looking at half the story (e.g. some numbers change
twice as fast as they think they should).

   I think supplying both options should probably show both sections
again, and make it not an error to do so, but I'm happy either way.

   Hugo.

-- 
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
  PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
  --- "He's a nutcase, you know. There's no getting away from it -- ---  
                     he'll end up with a knighthood"                     

[-- Attachment #2: Digital signature --]
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Re: [PATCH 1/2] Update btrfs filesystem df command

[Ilya Dryomov]

On Wed, Oct 03, 2012 at 09:38:52PM +0100, Hugo Mills wrote:
> On Wed, Oct 03, 2012 at 11:34:00PM +0300, Ilya Dryomov wrote:
> > On Wed, Oct 03, 2012 at 07:22:31PM +0200, Goffredo Baroncelli wrote:
> [snip]
> > > +static const char * const cmd_disk_free_usage[] = {
> > > +	"btrfs filesystem df [-d|-s][-k] <path> [<path>..]",
> > > +	"Show space usage information for a mount point(s).",
> > > +	"",
> > > +	"-k\tSet KB (1024 bytes) as unit",
> > > +	"-s\tShow the summary section only",
> > > +	"-d\tShow the detail section only",
> > > +	NULL
> > > +};
> > > +
> > > +static int cmd_disk_free(int argc, char **argv)
> > > +{
> > > +
> > > +	int 	flags=DF_SHOW_SUMMARY|DF_SHOW_DETAIL|DF_HUMAN_UNIT;
> > > +	int	i, more_than_one=0;
> > > +
> > > +	optind = 1;
> > > +	while(1){
> > > +		char	c = getopt(argc, argv, "dsk");
> > > +		if(c<0)
> > > +			break;
> > > +		switch(c){
> > > +			case 'd':
> > > +				flags &= ~DF_SHOW_SUMMARY;
> > > +				break;
> > > +			case 's':
> > > +				flags &= ~DF_SHOW_DETAIL;
> > > +				break;
> > > +			case 'k':
> > > +				flags &= ~DF_HUMAN_UNIT;
> > > +				break;
> > > +			default:
> > > +				usage(cmd_disk_free_usage);
> > > +		}
> > > +	}
> > > +
> > > +	if( !(flags & (DF_SHOW_SUMMARY|DF_SHOW_DETAIL)) ){
> > > +		fprintf(stderr, "btrfs filesystem df: it is not possible to specify -s AND -d\n");
> > 
> > This doesn't look right at all.  You are adding two switches and
> > specifying both of them is an error?  A little too much for a command
> > whose job is to do some basic math and pretty-print the result.
> > 
> > How about displaying just the summary by default and then adding a
> > *single* switch (-v or whatever) for summary+details?
> 
>    I'd prefer to see both sections by default. The reason for this is
> that without both sections, people tend to get confused because they
> don't know they're looking at half the story (e.g. some numbers change
> twice as fast as they think they should).

If we want both sections by default, there is no need for any switches
whatsoever, I think.

Thanks,

		Ilya

Re: [PATCH 1/2] Update btrfs filesystem df command

[Goffredo Baroncelli]

On 10/03/2012 10:38 PM, Hugo Mills wrote:
>>> +	if( !(flags&  (DF_SHOW_SUMMARY|DF_SHOW_DETAIL)) ){
>>> >  >  +		fprintf(stderr, "btrfs filesystem df: it is not possible to specify -s AND -d\n");
>> >
>> >  This doesn't look right at all.  You are adding two switches and
>> >  specifying both of them is an error?  A little too much for a command
>> >  whose job is to do some basic math and pretty-print the result.
>> >
>> >  How about displaying just the summary by default and then adding a
>> >  *single*  switch (-v or whatever) for summary+details?
>     I'd prefer to see both sections by default. The reason for this is
> that without both sections, people tend to get confused because they
> don't know they're looking at half the story (e.g. some numbers change
> twice as fast as they think they should).

I agree with Hugo. As default both the section should be showed.

>     I think supplying both options should probably show both sections
> again, and make it not an error to do so, but I'm happy either way.

Because the default is to show both the sections, passing a switch means 
"hide the other section". So passing both the switches means: "hide both 
the sections"...

This is the reason of the check.

I am thinking to remove both the switches... But today is too late...
Now I am seeing a reply by Ilya which reached this same conclusion... 
But today is still to late. Tomorrow I will rearrange the patch...



>
>     Hugo.

Goffredp

Re: [PATCH][BTRFS-PROGS][V2] btrfs filesystem df

[David Sterba]

On Wed, Oct 03, 2012 at 09:38:29PM +0200, Goffredo Baroncelli wrote:
> the output of the program ends with the "Metadata Single....". What you
> called "Help text" is a short description in the email.

Ah, I see. I still find it useful, would be good to include it in help
text or under a separate option.

david

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..96c9239 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBChunk\ type\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 4b0a9f9..ecd0916 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -214,6 +216,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBType\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4

[PATCH 2/2] Update help page

[Goffredo Baroncelli]

From: Goffredo Baroncelli <kreijack@inwind.it>

---
 man/btrfs.8.in |  100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)

diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index 9222580..7048273 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -27,6 +27,8 @@ btrfs \- control a btrfs filesystem
 .PP
 \fBbtrfs\fP \fBfilesystem label\fP\fI <dev> [newlabel]\fP
 .PP
+\fBbtrfs\fP \fBfilesystem df\fP\fI [-k] \fIpath [path..]\fR\fP
+.PP
 \fBbtrfs\fP \fBsubvolume find-new\fP\fI <subvolume> <last_gen>\fP
 .PP
 \fBbtrfs\fP \fBfilesystem balance\fP\fI <path> \fP
@@ -242,6 +244,104 @@ NOTE: Currently there are the following limitations:
 - the filesystem should not have more than one device.
 .TP
 
+\fBfilesystem df\fP [-k] \fIpath [path..]\fR
+
+Show space usage information for a mount point.
+
+\fIOptions\fP
+
+\fB-k\fP Set KB (1024 bytes) as unit
+
+\fIUsage information\fP
+
+.\"
+.\" this section is extract from 
+.\"	http://en.wikipedia.org/wiki/Btrfs#Chunk_and_device_trees
+The disk(s) of a btrfs filesystem are divided into chunks of 256 MB or more. 
+Chunks may be mirrored or striped across multiple devices, depending by
+the allocation policy.
+The mirroring/striping arrangement is transparent to the rest of the 
+file system, which simply sees the single, logical address space that 
+chunks are mapped into.
+Chunks are allocated on demand. In the default allocation policy 
+the data chunks are not duplicated and the metadata chunks
+are duplicated. This default can be changed during the filesystem
+creation, and in general the chunks allocation policy may change
+during the filesystem life. 
+
+Depending by the allocation policy a chunk may require a space on
+the disk greater than the logical space that it provides. E.g.
+a chunk DUPlicated or with a RAID1/RAID10 level 
+requires a space on the disk 
+two times greater than the logical space provided. 
+Different RAID levels
+have a different ratio disk-usage / logical space offered.
+
+Normally the file contents are stored in the Data chunks; however
+small files (which fit into a btree leaf) are stored in the 
+metadata chunks. So the computation of the \fIfree space\fP 
+and \fIused space\fP
+is complex: depending by the file size different 
+allocation policies are used.
+
+The command \fBbtrfs filesystem df\fP is used to query the status
+of the chunks, how many space on the disk(s) are used by the chunks, 
+how many space are available in the chunks, and an estimation of the free
+space of the filesystem.
+The output of the command \fBbtrfs filesystem df\fP shows:
+
+.RS
+.IP \fBDisk\ size\fP
+the total size of the disks which compose the filesystem.
+
+.IP \fBDisk\ allocated\fP\ or\ \fBSize_(disk)\fP
+the size of the area of the disks used by the chunks.
+
+.IP \fBDisk\ unallocated\fP 
+the size of the area of the disks which is free (i.e.
+the differences of the values above).
+
+.IP \fBLogical\ size\fP\ or\ \fBSize_(logical)\fP
+the available logical space of chunk. 
+
+.IP \fBUsed\fP
+the portion of the logical space used by the file and metadata.
+
+.IP \fBFree\ (estimated)\fP
+the estimated free space available. The evaluation 
+cannot be rigorous because it depends by the allocation policy (DUP,Single,
+RAID1...) of the metadata and data chunks. If every chunks is stored as
+"Single" the sum of the \fBfree (estimated)\fP space and the \fBused\fP 
+space  is equal to the \fBdisk size\fP.
+Otherwise if all the chunk are mirrored (raid1 or raid10) or duplicated
+the sum of the \fBfree (estimated)\fP space and the \fBused\fP space is
+half of the \fBdisk size\fP. Normally the \fBfree (estimated)\fP is between
+these two limits.
+
+.IP \fBData\ to\ disk\ ratio\fP
+the ratio betwen the \fBlogical size\fP and the \fBdisk allocated\fP.
+
+.IP \fBMode\fP
+the kind of allocation policy used by the chunk (e.g. DUPlicated,
+RAID1, RAID10, Single....)
+
+.IP \fBType\fP
+the kind of chunk (Data, Metdata, System...)
+
+.RE
+.RS
+\fINOTE\fP
+
+When a chunk is allocated, its disk-area is used and its allocation
+policy is fixed.
+A rebalance operation could rearrange the chunks, moving data in the chunks
+and resizing the allocated chunks. This causes the change of all the values 
+discussed above, with the exception of the \fBused\fP and 
+\fBdisk size\fP values.
+
+.RE
+.TP
+
 \fBfilesystem show\fR [--all-devices|<uuid>|<label>]\fR
 Show the btrfs filesystem with some additional info. If no \fIUUID\fP or 
 \fIlabel\fP is passed, \fBbtrfs\fR show info of all the btrfs filesystem.
-- 
1.7.10.4