On Fri, Aug 23, 2019 at 03:22:59PM +0800, Eryu Guan wrote:
> 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).
^^^^ should be 8192
Thanks,
Eryu
>
> 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>
> ---
> ltp/fsx.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/ltp/fsx.c b/ltp/fsx.c
> index 06d08e4e93f3..f6eb3308e8bc 100644
> --- a/ltp/fsx.c
> +++ b/ltp/fsx.c
> @@ -1825,6 +1825,14 @@ do { \
> TRIM_LEN(off, len, size); \
> } while (0)
>
> +#define CHECK_RANGE(off, len, size) \
> +do { \
> + if ((off + len * 2) > size) { \
> + log5(op, offset, size, -1, FL_SKIPPED); \
> + goto out; \
> + } \
> +} while (0)
> +
> void
> cleanup(int sig)
> {
> @@ -1989,6 +1997,7 @@ test(void)
> TRIM_OFF_LEN(offset, size, file_size);
> offset = offset & ~(block_size - 1);
> size = size & ~(block_size - 1);
> + CHECK_RANGE(offset, size, maxfilelen);
> do {
> offset2 = random();
> TRIM_OFF(offset2, maxfilelen);
> @@ -2003,6 +2012,7 @@ test(void)
> TRIM_OFF_LEN(offset, size, file_size);
> offset = offset & ~(block_size - 1);
> size = size & ~(block_size - 1);
> + CHECK_RANGE(offset, size, file_size);
> do {
> if (tries++ >= 30) {
> size = 0;
> @@ -2020,6 +2030,7 @@ test(void)
> offset -= offset % readbdy;
> if (o_direct)
> size -= size % readbdy;
> + CHECK_RANGE(offset, size, maxfilelen);
> do {
> offset2 = random();
> TRIM_OFF(offset2, maxfilelen);
> --
> 2.14.4.44.g2045bb6
