add openzfs dev list where it can be interested to ZoL and others too.
i think it is additional issue what was fixed by Tom Caputi with scrub.

-Igor

> On May 19, 2019, at 9:53 PM, Bill Sommerfeld <[email protected]> wrote:
> 
> On 05/18/19 14:27, Jerry Jelinek wrote:
>> I’ll see if I can reproduce this and I’ll also spend some time looking at 
>> the code to see if I can spot anything.
> 
> I've figured out how to reproduce it.   It doesn't appear to happen with 
> compress=lz4 for reasons I haven't yet figured out but it's easy to reproduce 
> by creating a bunch of very short random files in a filesystem using either 
> compress=zle or compress=lzjb.  (I haven't tried others).
> 
> 0) use a pool with embedded_data enabled.
> 
> 1) use a compression algorithm other than lz4:
> 
> zfs set compress=lzjb path/to/filesys
> 
> 2) create a bunch of small files with random content:
> 
> cd /path/to/filesys
> 
> for f in $(seq 1024)
> do
> dd if=/dev/urandom of=$f bs=16 count=1
> done
> 
> 3) scrub, watch "issued" value go nuts when the scan reaches the embedded 
> bp's containing the above files.
> 
> I'm convinced it's the BP_IS_EMBEDDED() thing and it appears it can be fixed 
> by:
> 
> diff --git a/usr/src/uts/common/fs/zfs/dsl_scan.c 
> b/usr/src/uts/common/fs/zfs/dsl_scan.c
> index ca82195178..b15b0931ed 100644
> --- a/usr/src/uts/common/fs/zfs/dsl_scan.c
> +++ b/usr/src/uts/common/fs/zfs/dsl_scan.c
> @@ -3431,6 +3431,9 @@ count_block(dsl_scan_t *scn, zfs_all_blkstats_t *zab, 
> const blkptr_t *bp)
> {
>        int i;
> 
> +       if (BP_IS_EMBEDDED(bp))
> +               return;
> +
>        /*
>         * Update the spa's stats on how many bytes we have issued.
>         * Sequential scrubs create a zio for each DVA of the bp. Each
> 
> 
> 
> 
> 
> 
> 
> 
> ------------------------------------------
> illumos: illumos-developer
> Permalink: 
> https://illumos.topicbox.com/groups/developer/Tffb445a29bb4df78-M1acc5f95b31153f9a00599b0
> Delivery options: https://illumos.topicbox.com/groups/developer/subscription

------------------------------------------
openzfs: openzfs-developer
Permalink: 
https://openzfs.topicbox.com/groups/developer/T3a803f548745e82d-Mab73e6b58c2ce33f7831d605
Delivery options: https://openzfs.topicbox.com/groups/developer/subscription

Reply via email to