A sample tool how to use the new ioctl
This is a standalone tool I've used to exercise the ioctl, simply pass
the name of a file and see the result. The numbers are a rough
estimate. It also takes the range arguments, but the ratio will be bogus
due to comparison to whole file (st_blocks), an exact extent length
from fiemap/filefrag is be the correct one.
david
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include sys/ioctl.h
#include sys/stat.h
#include fcntl.h
#include dirent.h
#include stdlib.h
#include stdio.h
#include string.h
#include inttypes.h
typedef uint64_t __u64;
typedef uint64_t u64;
#ifndef BTRFS_IOCTL_MAGIC
#define BTRFS_IOCTL_MAGIC 0x94
#endif
#ifndef BTRFS_IOC_COMPR_SIZE
#define BTRFS_IOC_COMPR_SIZE _IOR(BTRFS_IOCTL_MAGIC, 51, \
struct __local__btrfs_ioctl_compr_size_args)
#endif
struct __local__btrfs_ioctl_compr_size_args {
/* Range start, inclusive */
__u64 start; /* in */
/* Range end, exclusive */
__u64 end;/* in */
__u64 size; /* out */
__u64 reserved[2];
};
static u64 parse_size(char *s)
{
int len = strlen(s);
char c;
u64 mult = 1;
if (!isdigit(s[len - 1])) {
c = tolower(s[len - 1]);
switch (c) {
case 'e':
case 'E':
mult *= 1024;
case 't':
case 'T':
mult *= 1024;
case 'g':
case 'G':
mult *= 1024;
case 'm':
case 'M':
mult *= 1024;
case 'k':
case 'K':
mult *= 1024;
case 'b':
case 'B':
break;
default:
fprintf(stderr, Unknown size descriptor %c\n, c);
exit(1);
}
s[len - 1] = '\0';
}
return atoll(s) * mult;
}
static int open_file_or_dir(const char *fname)
{
int ret;
struct stat st;
DIR *dirstream;
int fd;
ret = stat(fname, st);
if (ret 0) {
perror(stat);
exit(1);
}
if (S_ISDIR(st.st_mode)) {
dirstream = opendir(fname);
if (!dirstream) {
perror(opendir);
exit(1);
}
fd = dirfd(dirstream);
} else {
fd = open(fname, O_RDONLY);
}
if (fd 0) {
perror(open);
exit(1);
}
return fd;
}
static char buf[64];
static const char* end_or_eof(u64 end)
{
if (end == (u64)-1)
return EOF;
snprintf(buf, 64, %llu, (unsigned long long)end);
return buf;
}
int main(int argc, char **argv)
{
int fd;
int ret;
u64 cblocks;
unsigned long sblocks;
struct stat st;
struct __local__btrfs_ioctl_compr_size_args args;
if (argc 2) {
printf(Usage: btrfs-compr-size file [start [end] ]\n);
exit(1);
}
fd = open_file_or_dir(argv[1]);
if (fd == -1) {
perror(open);
exit(1);
}
if (argc = 3)
args.start = parse_size(argv[2]);
else
args.start = 0;
if (argc = 4)
args.end = parse_size(argv[3]);
else
args.end = (u64)-1;
ret = ioctl(fd, BTRFS_IOC_COMPR_SIZE, args);
if (ret 0) {
perror(ioctl);
exit(1);
}
fstat(fd, st);
cblocks=args.size;
sblocks=st.st_blocks;
printf(Compressed size of %s [%llu,%s)\n, argv[1],
(unsigned long long)args.start,
end_or_eof(args.end));
printf( compr size/512: % 11lu\n, cblocks);
printf( stat blocks/512: % 11lu\n, sblocks);
if (sblocks)
printf( compr/stat*100: % 14.2f%%\n, (((float)cblocks) / sblocks) * 100);
else
printf( compr/stat*100: % 14.2f%%\n, (float)0);
return 0;
}
Re: A sample tool how to use the new ioctl
On Mon, Dec 19, 2011 at 03:25:39PM +0100, David Sterba wrote: This is a standalone tool I've used to exercise the ioctl, simply pass the name of a file and see the result. The numbers are a rough estimate. It also takes the range arguments, but the ratio will be bogus due to comparison to whole file (st_blocks), an exact extent length from fiemap/filefrag is be the correct one. Thanks Dave. Could you please add this to btrfs filesystem stat filename -chris -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: A sample tool how to use the new ioctl
On Mon, Dec 19, 2011 at 09:47:06AM -0500, Chris Mason wrote:
On Mon, Dec 19, 2011 at 03:25:39PM +0100, David Sterba wrote:
This is a standalone tool I've used to exercise the ioctl, simply pass
Could you please add this to btrfs filesystem stat filename
Here it is, but I haven't really thought about the userspace interface and
calling it 'stat' just for reading compressed size does not seem right (and I
have renamed to 'csize' for now).
I will extend the ioctl to return the uncompressed size as well, it is provided
by the extent anyway. The original implementation returned just one u64 for the
whole file, I did the range-aware version because the lock_extent blocked for a
long time when the file was being modified and it could be avoided. However I
missed the options to utilize the information provided by the extents,
so this is not a final version.
From: David Sterba dste...@suse.cz
Signed-off-by: David Sterba dste...@suse.cz
---
btrfs.c |9 -
btrfs_cmds.c | 53 +
btrfs_cmds.h |1 +
ioctl.h | 11 +++
4 files changed, 73 insertions(+), 1 deletions(-)
diff --git a/btrfs.c b/btrfs.c
index 1def354..5ce207a 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -128,7 +128,14 @@ static struct Command commands[] = {
filesystem label, device [newlabel]\n
With one argument, get the label of filesystem on device.\n
If newlabel is passed, set the filesystem label to newlabel.\n
- The filesystem must be unmounted.\n
+ The filesystem must be unmounted.
+ },
+ { do_compr_size, -1,
+ filesystem csize, [-s start] [-e end] file\n
+ Read compressed size of extents in the range [start,end)\n
+ -s start range start inclusive\n
+ -e endrange end exclusive\n,
+ NULL
},
{ do_scrub_start, -1,
scrub start, [-Bdqr] path|device\n
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index b59e9cb..4c8bf5c 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -1305,3 +1305,56 @@ out:
free(inodes);
return ret;
}
+
+int do_compr_size(int argc, char **argv)
+{
+ int ret;
+ int fd;
+ struct btrfs_ioctl_compr_size_args args;
+
+ args.start = 0;
+ args.end = (u64)-1;
+ optind = 1;
+ while (1) {
+ int c = getopt(argc, argv, s:e:);
+ if (c 0)
+ break;
+ switch (c) {
+ case 's':
+ args.start = parse_size(optarg);
+ break;
+ case 'e':
+ args.end = parse_size(optarg);
+ break;
+ default:
+ fprintf(stderr, ERROR: Invalid arguments for csize\n);
+ return 1;
+ }
+ }
+
+ if (args.start args.end) {
+ fprintf(stderr, ERROR: Invalid range for csize\n);
+ return 1;
+ }
+
+ if (argc - optind == 0) {
+ fprintf(stderr, ERROR: Invalid arguments for csize\n);
+ return 1;
+ }
+ argc -= optind;
+
+ fd = open_file_or_dir(argv[optind]);
+ if (fd 0) {
+ fprintf(stderr, ERROR: can't access '%s'\n, argv[optind]);
+ return 1;
+ }
+
+ ret = ioctl(fd, BTRFS_IOC_COMPR_SIZE, args);
+ if (ret 0) {
+ fprintf(stderr, ERROR: ioctl returned %d, errno %d %s\n, ret,
errno, strerror(errno));
+ return errno;
+ }
+
+ printf(Compressed size: %llu\n, args.size 9);
+ return 0;
+}
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 81182b1..d171214 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -42,3 +42,4 @@ int open_file_or_dir(const char *fname);
int do_ino_to_path(int nargs, char **argv);
int do_logical_to_ino(int nargs, char **argv);
char *path_for_root(int fd, u64 root);
+int do_compr_size(int argc, char **argv);
diff --git a/ioctl.h b/ioctl.h
index 1ae7537..792ffc0 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -224,6 +224,15 @@ struct btrfs_ioctl_logical_ino_args {
__u64 inodes;
};
+struct btrfs_ioctl_compr_size_args {
+ /* Range start, inclusive */
+ __u64 start; /* in */
+ /* Range end, exclusive */
+ __u64 end;/* in */
+ __u64 size; /* out */
+ __u64 reserved[2];
+};
+
/* BTRFS_IOC_SNAP_CREATE is no longer used by the btrfs command */
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
@@ -277,5 +286,7 @@ struct btrfs_ioctl_logical_ino_args {
struct btrfs_ioctl_ino_path_args)
#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
