[02/11,RESEND] filefrag: Output fragmentation score

This patch adds the fragmentation score to the output of filefrag.
The threshold that shows whether a fragment is good or not comes from
"blocksize * 8 - 2048". "blocksize * 8 - 2048" is the maximum number of
contiguous blocks which we can get from empty blockgroup containing some
metadata blocks.

For example, filefrag shows fragmentation score as follows:

# filefrag /mnt/mp1/testfile
/mnt/mp1/testfile: 4 extents found
Fragmentation score: 33 (found a little bit fragmentation)

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
---
 misc/Makefile.in |    4 ++--
 misc/filefrag.c  |   28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 2 deletions(-)

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

On 2011-06-15, at 12:33 AM, Kazuya Mio <k-mio@sx.jp.nec.com> wrote:
> This patch adds the fragmentation score to the output of filefrag.
> The threshold that shows whether a fragment is good or not comes from
> "blocksize * 8 - 2048". "blocksize * 8 - 2048" is the maximum number of
> contiguous blocks which we can get from empty blockgroup containing some
> metadata blocks.
> 
> For example, filefrag shows fragmentation score as follows:
> 
> # filefrag /mnt/mp1/testfile
> /mnt/mp1/testfile: 4 extents found
> Fragmentation score: 33 (found a little bit fragmentation)

It would probably be just as clear, and a lot more compact to keep only a single line per file:  

# filefrag /mnt/mp1/testfile
/mnt/mp1/testfile: 4 extents found, 33% fragmented

or similar like "..., fragmentation score 33/100" if we don't like to use percent. 

> Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
> ---
> misc/Makefile.in |    4 ++--
> misc/filefrag.c  |   28 ++++++++++++++++++++++++++++
> 2 files changed, 30 insertions(+), 2 deletions(-)
> diff --git a/misc/Makefile.in b/misc/Makefile.in
> index 86ee53f..19eaa43 100644
> --- a/misc/Makefile.in
> +++ b/misc/Makefile.in
> @@ -306,9 +306,9 @@ e2freefrag: $(E2FREEFRAG_OBJS)
>    $(E) "    LD $@"
>    $(Q) $(CC) $(ALL_LDFLAGS) -o e2freefrag $(E2FREEFRAG_OBJS) $(LIBS)
> 
> -filefrag: $(FILEFRAG_OBJS)
> +filefrag: $(FILEFRAG_OBJS) $(DEPLIBS_E2P)
>    $(E) "    LD $@"
> -    $(Q) $(CC) $(ALL_LDFLAGS) -o filefrag $(FILEFRAG_OBJS) 
> +    $(Q) $(CC) $(ALL_LDFLAGS) -o filefrag $(FILEFRAG_OBJS) $(DEPLIBS_E2P)
> 
> filefrag.profiled: $(PROFILED_FILEFRAG_OBJS)
>    $(E) "    LD $@"
> diff --git a/misc/filefrag.c b/misc/filefrag.c
> index 2795e15..ca9833a 100644
> --- a/misc/filefrag.c
> +++ b/misc/filefrag.c
> @@ -41,6 +41,7 @@ extern int optind;
> #include <linux/fd.h>
> #include <ext2fs/ext2_types.h>
> #include <ext2fs/fiemap.h>
> +#include "e2p/e2p.h"
> 
> int verbose = 0;
> int no_bs = 0;        /* Don't use the files blocksize, use 1K blocksize */
> @@ -279,6 +280,7 @@ static void frag_report(const char *filename)
>    int        is_ext2 = 0;
>    static int    once = 1;
>    unsigned int    flags;
> +    int score;
>    int rc;
> 
> #ifdef HAVE_OPEN64
> @@ -379,6 +381,32 @@ static void frag_report(const char *filename)
>            (expected>1) ? "s" : "");
>    else
>        fputc('\n', stdout);
> +
> +    if (!xattr_map) {
> +        /*
> +         * Get the fragmentation score.
> +         * NOTE: 2048 means the maximum block region of mballoc.
> +         */
> +        score = get_fragment_score(fd,
> +            (fsinfo.f_bsize * 8 - 2048) * fsinfo.f_bsize);
> +
> +        /*
> +         * Print fragmentation score with some comments
> +         * 0-30 no problem, 31-55 a little bit fragmented,
> +         * 56- needs defrag
> +         */
> +        if (score < 0)
> +            ;
> +        else if (score <= 30)
> +            printf("Fragmentation score: %d (no problem)\n", score);
> +        else if (score <= 55)
> +            printf("Fragmentation score: %d "
> +                "(found a little bit fragmentation)\n", score);
> +        else
> +            printf("Fragmentation score: %d "
> +                "(need to do e4defrag command)\n", score);
> +    }
> +
>    close(fd);
>    once = 0;
> }
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html