On 8/23/17 10:11 AM, Nikolay Borisov wrote:
> Introduce two optional arguments which can be used to perform fiemap queries
> for a particular range in a file. Those are 'offset' and 'length' they can be
> used like so:
>
> xfs_io -c "fiemap 0 12k" - query for extents covering the first 12kb of the
> target file.
>
> Now that such queries are supposed also modify the logic for printing the last
> hole to only cover the range which is asked. So if we ask for 0-10kb and the
> range 8k-12k is actually a whole, then limit the last whole only to this range:
>
> So for a file which has the following contents :
>
> |-----hole-------|-------data--------|-----hole-----|
> 0 8k 12k 16k
>
> The output would be:
>
> xfs_io -c "fiemap -v 0 13k" test-dir/fragmented-file
> test-dir/fragmented-file:
> EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
> 0: [0..15]: hole 16
> 1: [16..23]: 897847296..897847303 8 0x0
> 2: [24..25]: hole 2
>
> Furthermore in cases where the queried range is covered by a whole then the
> existing while() loop would have never executed, due to num_exents = 0. Fix this
> by converting it to a do {} while ()
>
> _
>
> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> io/fiemap.c | 75 +++++++++++++++++++++++++++++++++++++++----------------
> man/man8/xfs_io.8 | 6 +++--
> 2 files changed, 57 insertions(+), 24 deletions(-)
>
> diff --git a/io/fiemap.c b/io/fiemap.c
> index ef54b265ab91..2e03a81dc57a 100644
> --- a/io/fiemap.c
> +++ b/io/fiemap.c
> @@ -27,7 +27,7 @@
>
> static cmdinfo_t fiemap_cmd;
> static const __u64 blocksize = 512;
> -static int max_extents = 0;
> +static int max_extents = -1;
>
> static void
> fiemap_help(void)
> @@ -38,6 +38,7 @@ fiemap_help(void)
> "\n"
> " Example:\n"
> " 'fiemap -v' - tabular format verbose map\n"
> +" 'fiemap 0 4k' - print fiemap extents for 0-4k range\n"
> "\n"
> " fiemap prints the map of disk blocks used by the current file.\n"
> " The map lists each extent used by the file, as well as regions in the\n"
> @@ -231,9 +232,14 @@ fiemap_f(
> int boff_w = 16;
> int tot_w = 5; /* 5 since its just one number */
> int flg_w = 5;
> - __u64 last_logical = 0;
> + __u64 start_offset = 0, last_logical = 0;
> + __u64 len = -1;
> + __u64 end_offset = 0, llast;
> + size_t fsblocksize, fssectsize;
> struct stat st;
>
> + init_cvtnum(&fsblocksize, &fssectsize);
> +
> while ((c = getopt(argc, argv, "aln:v")) != EOF) {
> switch (c) {
> case 'a':
> @@ -253,7 +259,41 @@ fiemap_f(
> }
> }
>
> - ret = get_extent_count(file->fd, last_logical, -1);
> +
> + if (optind < argc) {
> + off64_t start = cvtnum(fsblocksize, fssectsize, argv[optind]);
> + if (start_offset < 0) {
This is testing the wrong var.
Ok, I got totally distracted on this; looking to see if it can't just be
cleaned up wholesale... it's still so full of weird special cases :/
-Eric
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