On Sat, Aug 24, 2019 at 10:41:07PM +0800, Eryu Guan wrote:
> From: Eryu Guan <eguan@xxxxxxxxxxxxxxxxx>
>
> In CLONE/DEDUPE/COPY RANGE operations, we pick a "offset" and "size"
> first, then find a suitable "offset2" by looping if there's overlap
> (|offset2-offset| < size) or final file size is greater than max
> file size (offset2 + size > maxfilelen).
>
> But it's possible that there's no such suitable offset2 and we loop
> forever. e.g. block_size = 4096, offset = 0, size = 4096 and
> maxfilelen is a value smaller than 8212 (which could be set via '-l'
> option).
>
> Fix it by making sure maxfilelen/file_size is big enough to hold
> 'size' bytes from 'offset2', and just skip this operation if not.
>
> Signed-off-by: Eryu Guan <eguan@xxxxxxxxxxxxxxxxx>
Ping on this patch.
Eryu
> ---
> v2:
> - don't use macro with ugly hacks, use an inline function instead
>
> ltp/fsx.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/ltp/fsx.c b/ltp/fsx.c
> index 06d08e4e93f3..890666ab6140 100644
> --- a/ltp/fsx.c
> +++ b/ltp/fsx.c
> @@ -1911,6 +1911,15 @@ fail:
> return 0;
> }
>
> +/* Check if range operations are possible to find a suitable offset */
> +static inline bool check_range(unsigned long op, unsigned long off,
> + unsigned long len, unsigned long size)
> +{
> + bool ret = ((off + len * 2) <= size);
> + if (!ret)
> + log5(op, off, len, -1, FL_SKIPPED);
> + return ret;
> +}
>
> int
> test(void)
> @@ -1989,6 +1998,8 @@ test(void)
> TRIM_OFF_LEN(offset, size, file_size);
> offset = offset & ~(block_size - 1);
> size = size & ~(block_size - 1);
> + if (!check_range(op, offset, size, maxfilelen))
> + goto out;
> do {
> offset2 = random();
> TRIM_OFF(offset2, maxfilelen);
> @@ -2003,6 +2014,8 @@ test(void)
> TRIM_OFF_LEN(offset, size, file_size);
> offset = offset & ~(block_size - 1);
> size = size & ~(block_size - 1);
> + if (!check_range(op, offset, size, file_size))
> + goto out;
> do {
> if (tries++ >= 30) {
> size = 0;
> @@ -2020,6 +2033,8 @@ test(void)
> offset -= offset % readbdy;
> if (o_direct)
> size -= size % readbdy;
> + if (!check_range(op, offset, size, maxfilelen))
> + goto out;
> do {
> offset2 = random();
> TRIM_OFF(offset2, maxfilelen);
> --
> 2.21.0
