On 3.06.19 г. 9:40 ч., Qu Wenruo wrote:
> If a filesystem doesn't map its logical address space (normally the
> bytenr/blocknr returned by fiemap) directly to its devices(s), the
> following assumptions used in the test case is no longer true:
> - trim range start beyond the end of fs should fail
> - trim range start beyond the end of fs with len set should fail
>
> Under the following example, even with just one device, btrfs can still
> trim the fs correctly while breaking above assumption:
>
> 0 1G 1.25G
> |---------------|///////////////|-----------------| <- btrfs logical
> | address space
> ------------ mapped as SINGLE
> |
> 0 V 256M
> |///////////////| <- device address space
>
> Thus trim range start=1G len=256M will cause btrfs to trim the 256M
> block group, thus return correct result.
>
> Furthermore, there is no cleared defined behavior for whether a fs should
> trim the unmapped space. (only for indirectly mapped fs)
>
> Btrfs currently will always trim the unmapped space, but the behavior
> can change as large trim can be very expensive.
>
> Despite the change to skip certain tests for btrfs, still run the
> following tests for btrfs:
> - trim start=U64_MAX with lenght set
> This will expose a bug that btrfs doesn't check overflow of the range.
> This bug will be fixed soon.
>
> - trim beyond the end of the fs
> This will expose a bug where btrfs could send trim command beyond the
> end of its device.
> This bug is a regression, can be fixed by reverting c2d1b3aae336 ("btrfs:
> Honour FITRIM range constraints during free space trim")
>
> With proper fixes for btrfs, this test case should pass on btrfs, ext4,
> xfs.
>
> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
> ---
> changelog:
> v2:
> - Return 0/1 instead of echo "1"/"0" for _is_fs_directly_mapped
> Although it may be a little confusing, but make
> "if _is_fs_directly_mapped; then" much cleaner.
> - Comment change.
> ---
Nope, the output is rather unhelpful. Current misc-next of btrfs fails
and the output is:
[+] Start = 2^64-1 and len is set (should fail)
[+] Trim an empty fs
13554941952 trimed
[+] Try to trim beyond the end of the fs
[+] Try to trim the fs with large enough len
15727198208 trimed
generic/260 [failed, exit status 1]
There is no 260.out file which is supposed to contain some of the error
strings which in turn makes the test tedious to debug...
<snip>
