[0/2] revert 9pfs reply truncation, wait for free room to reply

Message

Stefano Stabellini May 20, 2020, 1:47 a.m. UTC

Hi all,

This short series reverts commit 16724a173049ac29c7b5ade741da93a0f46edff
becauses it is the cause for https://bugs.launchpad.net/bugs/1877688.

The original issue addressed by 16724a173049ac29c7b5ade741da93a0f46edff
is solved differently in this series by using qemu_coroutine_yield() to
wait for the client to free more data from the ring before sending the
reply.

Cheers,

Stefano

Comments

[e-mail] May 20, 2020, 7:57 a.m. UTC | #1

Patchew URL: https://patchew.org/QEMU/alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Message-id: alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s
Subject: [PATCH 0/2] revert 9pfs reply truncation, wait for free room to reply
Type: series

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
Switched to a new branch 'test'
1fcf375 xen/9pfs: yield when there isn't enough room on the ring
8e197ec Revert "9p: init_in_iov_from_pdu can truncate the size"

=== OUTPUT BEGIN ===
1/2 Checking commit 8e197ec8340d (Revert "9p: init_in_iov_from_pdu can truncate the size")
2/2 Checking commit 1fcf3751db74 (xen/9pfs: yield when there isn't enough room on the ring)
ERROR: memory barrier without comment
#41: FILE: hw/9pfs/xen-9p-backend.c:203:
+    smp_wmb();

ERROR: memory barrier without comment
#56: FILE: hw/9pfs/xen-9p-backend.c:213:
+    smp_wmb();

ERROR: memory barrier without comment
#68: FILE: hw/9pfs/xen-9p-backend.c:302:
+    smp_rmb();

total: 3 errors, 0 warnings, 50 lines checked

Patch 2/2 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [https://patchew.org/].
Please send your feedback to [e-mail]

Greg Kurz May 20, 2020, 1:42 p.m. UTC | #2

On Wed, 20 May 2020 00:57:42 -0700 (PDT)
[e-mail] wrote:

> Patchew URL: https://patchew.org/QEMU/alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s/
> 
> 
> 
> Hi,
> 
> This series seems to have some coding style problems. See output below for
> more information:
> 
> Message-id: alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s
> Subject: [PATCH 0/2] revert 9pfs reply truncation, wait for free room to reply
> Type: series
> 
> === TEST SCRIPT BEGIN ===
> #!/bin/bash
> git rev-parse base > /dev/null || exit 0
> git config --local diff.renamelimit 0
> git config --local diff.renames True
> git config --local diff.algorithm histogram
> ./scripts/checkpatch.pl --mailback base..
> === TEST SCRIPT END ===
> 
> Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
> Switched to a new branch 'test'
> 1fcf375 xen/9pfs: yield when there isn't enough room on the ring
> 8e197ec Revert "9p: init_in_iov_from_pdu can truncate the size"
> 
> === OUTPUT BEGIN ===
> 1/2 Checking commit 8e197ec8340d (Revert "9p: init_in_iov_from_pdu can truncate the size")
> 2/2 Checking commit 1fcf3751db74 (xen/9pfs: yield when there isn't enough room on the ring)
> ERROR: memory barrier without comment
> #41: FILE: hw/9pfs/xen-9p-backend.c:203:
> +    smp_wmb();
> 
> ERROR: memory barrier without comment
> #56: FILE: hw/9pfs/xen-9p-backend.c:213:
> +    smp_wmb();
> 
> ERROR: memory barrier without comment
> #68: FILE: hw/9pfs/xen-9p-backend.c:302:
> +    smp_rmb();
> 

Indeed some comments would definitely provide better understanding.

> total: 3 errors, 0 warnings, 50 lines checked
> 
> Patch 2/2 has style problems, please review.  If any of these errors
> are false positives report them to the maintainer, see
> CHECKPATCH in MAINTAINERS.
> 
> === OUTPUT END ===
> 
> Test command exited with code: 1
> 
> 
> The full log is available at
> http://patchew.org/logs/alpine.DEB.2.21.2005191651130.27502@sstabellini-ThinkPad-T480s/testing.checkpatch/?type=message.
> ---
> Email generated automatically by Patchew [https://patchew.org/].
> Please send your feedback to [e-mail]