[v2] Miscellaneous error handling fixes

[PATCH v2 02/14] block/file-posix: Fix check_cache_dropped() error handling

Markus Armbruster posted 14 patches 5 years, 9 months ago

Diff against v1
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Maintainers: Juan Quintela <quintela@redhat.com>, Kevin Wolf <kwolf@redhat.com>, John Snow <jsnow@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Richard Henderson <rth@twiddle.net>, Michael Roth <mdroth@linux.vnet.ibm.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, "Gonglei (Arei)" <arei.gonglei@huawei.com>, Peter Maydell <peter.maydell@linaro.org>, Max Reitz <mreitz@redhat.com>, Stefano Stabellini <sstabellini@kernel.org>, Paul Durrant <paul@xen.org>, Anthony Perard <anthony.perard@citrix.com>, Jason Wang <jasowang@redhat.com>, Hailiang Zhang <zhang.zhanghailiang@huawei.com>, Paolo Bonzini <pbonzini@redhat.com>

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[PATCH v2 02/14] 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>
---
 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