diff mbox series

[PULL,1/2] io_uring: fix short read slow path

Message ID 20220707081247.1416955-2-stefanha@redhat.com
State New
Headers show
Series [PULL,1/2] io_uring: fix short read slow path | expand

Commit Message

Stefan Hajnoczi July 7, 2022, 8:12 a.m. UTC 
From: Dominique Martinet <dominique.martinet@atmark-techno.com>

sqeq.off here is the offset to read within the disk image, so obviously
not 'nread' (the amount we just read), but as the author meant to write
its current value incremented by the amount we just read.

Normally recent versions of linux will not issue short reads,
but it can happen so we should fix this.

This lead to weird image corruptions when short read happened

Fixes: 6663a0a33764 ("block/io_uring: implements interfaces for io_uring")
Link: https://lkml.kernel.org/r/YrrFGO4A1jS0GI0G@atmark-techno.com
Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Message-Id: <20220630010137.2518851-1-dominique.martinet@atmark-techno.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 block/io_uring.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/block/io_uring.c b/block/io_uring.c
index d48e472e74..b238661740 100644
--- a/block/io_uring.c
+++ b/block/io_uring.c
@@ -89,7 +89,7 @@  static void luring_resubmit_short_read(LuringState *s, LuringAIOCB *luringcb,
     trace_luring_resubmit_short_read(s, luringcb, nread);
 
     /* Update read position */
-    luringcb->total_read = nread;
+    luringcb->total_read += nread;
     remaining = luringcb->qiov->size - luringcb->total_read;
 
     /* Shorten qiov */
@@ -103,7 +103,7 @@  static void luring_resubmit_short_read(LuringState *s, LuringAIOCB *luringcb,
                       remaining);
 
     /* Update sqe */
-    luringcb->sqeq.off = nread;
+    luringcb->sqeq.off += nread;
     luringcb->sqeq.addr = (__u64)(uintptr_t)luringcb->resubmit_qiov.iov;
     luringcb->sqeq.len = luringcb->resubmit_qiov.niov;