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[Qemu-devel] [PATCH 11/15] fix qemu_aio_flush
From: |
Glauber Costa |
Subject: |
[Qemu-devel] [PATCH 11/15] fix qemu_aio_flush |
Date: |
Wed, 17 Jun 2009 13:10:00 -0400 |
From: Andrea Arcangeli <address@hidden>
qemu_aio_wait by invoking the bh or one of the aio completion
callbacks, could end up submitting new pending aio, breaking the
invariant that qemu_aio_flush returns only when no pending aio is
outstanding (possibly a problem for migration as such).
Signed-off-by: Andrea Arcangeli <address@hidden>
Signed-off-by: Christoph Hellwig <address@hidden>
Acked-by: Kevin Wolf <address@hidden>
Signed-off-by: Glauber Costa <address@hidden>
---
aio.c | 8 ++++++--
qemu-aio.h | 7 ++++---
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/aio.c b/aio.c
index 11fbb6c..dc9b85d 100644
--- a/aio.c
+++ b/aio.c
@@ -103,11 +103,15 @@ void qemu_aio_flush(void)
do {
ret = 0;
+ /*
+ * If there are pending emulated aio start them now so flush
+ * will be able to return 1.
+ */
+ qemu_aio_wait();
+
LIST_FOREACH(node, &aio_handlers, node) {
ret |= node->io_flush(node->opaque);
}
-
- qemu_aio_wait();
} while (ret > 0);
}
diff --git a/qemu-aio.h b/qemu-aio.h
index 7967829..f262344 100644
--- a/qemu-aio.h
+++ b/qemu-aio.h
@@ -24,9 +24,10 @@ typedef int (AioFlushHandler)(void *opaque);
* outstanding AIO operations have been completed or cancelled. */
void qemu_aio_flush(void);
-/* Wait for a single AIO completion to occur. This function will until a
- * single AIO opeartion has completed. It is intended to be used as a looping
- * primative when simulating synchronous IO based on asynchronous IO. */
+/* Wait for a single AIO completion to occur. This function will wait
+ * until a single AIO event has completed and it will ensure something
+ * has moved before returning. This can issue new pending aio as
+ * result of executing I/O completion or bh callbacks. */
void qemu_aio_wait(void);
/* Register a file descriptor and associated callbacks. Behaves very similarly
--
1.6.2.2
- [Qemu-devel] [PATCH 01/15] net: Fix -net socket, listen (Jan Kiszka), (continued)
- [Qemu-devel] [PATCH 01/15] net: Fix -net socket, listen (Jan Kiszka), Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 02/15] Minimal ethernet frame length is 64 bytes., Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 03/15] Don't send all gratuitous packets at once., Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 04/15] serial: fix lost character after sysrq, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 05/15] e1000: Ignore reset command, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 06/15] VNC: Fix memory allocation (wrong structure size)., Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 07/15] fix raw_pread_aligned return value, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 08/15] BACKPORT: Register reset functions for e1000 and rtl8139, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 09/15] BACKPORT: Update irqs on reset and device load, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 10/15] BACKPORT: Add rtc reset function., Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 11/15] fix qemu_aio_flush,
Glauber Costa <=
- [Qemu-devel] [PATCH 12/15] QEMU KVM: i386: Fix the cpu reset state, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 13/15] kvm: Fix IRQ injection into full queue, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 14/15] Prevent CD-ROM media eject while device is locked, Glauber Costa, 2009/06/17
- [Qemu-devel] [PATCH 15/15] Fix vga_screen_dump_blank() PPM generation, Glauber Costa, 2009/06/17
- [Qemu-devel] Re: [PATCH 09/15] BACKPORT: Update irqs on reset and device load, Blue Swirl, 2009/06/17
- [Qemu-devel] Re: [PATCH 09/15] BACKPORT: Update irqs on reset and device load, Glauber Costa, 2009/06/17
Re: [Qemu-devel] [GIT PULL 00/15] Stable branch update 2009-06-17, Anthony Liguori, 2009/06/17