Miscellaneous patches for 2020-04-29

[PULL 12/32] block/file-posix: Fix check_cache_dropped() error handling

Markus Armbruster posted 32 patches 5 years, 9 months ago

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Maintainers: Palmer Dabbelt <palmer@dabbelt.com>, Peter Maydell <peter.maydell@linaro.org>, Hailiang Zhang <zhang.zhanghailiang@huawei.com>, BALATON Zoltan <balaton@eik.bme.hu>, Michael Roth <mdroth@linux.vnet.ibm.com>, Gerd Hoffmann <kraxel@redhat.com>, "Gonglei (Arei)" <arei.gonglei@huawei.com>, Stefan Hajnoczi <stefanha@redhat.com>, Markus Armbruster <armbru@redhat.com>, Juan Quintela <quintela@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, Wen Congyang <wencongyang2@huawei.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Fam Zheng <fam@euphon.net>, Max Reitz <mreitz@redhat.com>, Bastian Koppelmann <kbastian@mail.uni-paderborn.de>, Stefano Stabellini <sstabellini@kernel.org>, Kevin Wolf <kwolf@redhat.com>, Aleksandar Rikalo <aleksandar.rikalo@rt-rk.com>, Richard Henderson <rth@twiddle.net>, Aurelien Jarno <aurelien@aurel32.net>, Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, John Snow <jsnow@redhat.com>, Bandan Das <bsd@redhat.com>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Xie Changlong <xiechanglong.d@gmail.com>, "Philippe Mathieu-Daudé" <philmd@redhat.com>, Anthony Perard <anthony.perard@citrix.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Alistair Francis <Alistair.Francis@wdc.com>, Jeff Cody <codyprime@gmail.com>, Sagar Karandikar <sagark@eecs.berkeley.edu>, Eduardo Habkost <ehabkost@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Alexander Bulekov <alxndr@bu.edu>, Thomas Huth <thuth@redhat.com>, Paul Durrant <paul@xen.org>, Laurent Vivier <lvivier@redhat.com>, Corey Minyard <cminyard@mvista.com>, Jason Wang <jasowang@redhat.com>

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[PULL 12/32] block/file-posix: Fix check_cache_dropped() error handling

Posted by Markus Armbruster 5 years, 9 months ago

The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

check_cache_dropped() calls error_setg() in a loop.  It fails to break
the loop in one instance.  If a subsequent iteration error_setg()s
again, it trips error_setv()'s assertion.

Fix it to break the loop.

Fixes: 31be8a2a97ecba7d31a82932286489cac318e9e9
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200422130719.28225-3-armbru@redhat.com>
---
 block/file-posix.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 7e19bbff5f..094e3b0212 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2691,10 +2691,13 @@ static void check_cache_dropped(BlockDriverState *bs, Error **errp)
         vec_end = DIV_ROUND_UP(length, page_size);
         for (i = 0; i < vec_end; i++) {
             if (vec[i] & 0x1) {
-                error_setg(errp, "page cache still in use!");
                 break;
             }
         }
+        if (i < vec_end) {
+            error_setg(errp, "page cache still in use!");
+            break;
+        }
     }
 
     if (window) {
-- 
2.21.1

Re: [PULL 12/32] block/file-posix: Fix check_cache_dropped() error handling

Posted by Stefan Hajnoczi 5 years, 9 months ago

On Wed, Apr 29, 2020 at 09:20:28AM +0200, Markus Armbruster wrote:
> The Error ** argument must be NULL, &error_abort, &error_fatal, or a
> pointer to a variable containing NULL.  Passing an argument of the
> latter kind twice without clearing it in between is wrong: if the
> first call sets an error, it no longer points to NULL for the second
> call.
> 
> check_cache_dropped() calls error_setg() in a loop.  It fails to break
> the loop in one instance.  If a subsequent iteration error_setg()s
> again, it trips error_setv()'s assertion.
> 
> Fix it to break the loop.
> 
> Fixes: 31be8a2a97ecba7d31a82932286489cac318e9e9
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Message-Id: <20200422130719.28225-3-armbru@redhat.com>
> ---
>  block/file-posix.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Thanks for fixing this bug!

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>