[Qemu-devel] [PATCH v6 01/22] ide/ahci: Check for -ECANCELED in aio callbacks

[Fam Zheng <famz@redhat.com>]

Before, bdrv_aio_cancel will either complete the request (like normal)
and call CB with an actual return code, or skip calling the request (for
example when the IO req is not submitted by thread pool yet).

We will change bdrv_aio_cancel to do it differently: always call CB
before return, with either [1] a normal req completion ret code, or [2]
ret == -ECANCELED. So the callers' callback must accept both cases. The
existing logic works with case [1], but not [2].

The simplest transition of callback code is do nothing in case [2], just
as if the CB is not called by the bdrv_aio_cancel() call.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 hw/ide/ahci.c |  3 +++
 hw/ide/core.c | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 0ee713b..3067aa2 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -791,6 +791,9 @@ static void ncq_cb(void *opaque, int ret)
     NCQTransferState *ncq_tfs = (NCQTransferState *)opaque;
     IDEState *ide_state = &ncq_tfs->drive->port.ifs[0];
 
+    if (ret == -ECANCELED) {
+        return;
+    }
     /* Clear bit for this tag in SActive */
     ncq_tfs->drive->port_regs.scr_act &= ~(1 << ncq_tfs->tag);
 
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 191f893..2f2d3b4 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -568,6 +568,9 @@ static void ide_sector_read_cb(void *opaque, int ret)
     s->pio_aiocb = NULL;
     s->status &= ~BUSY_STAT;
 
+    if (ret == -ECANCELED) {
+        return;
+    }
     bdrv_acct_done(s->bs, &s->acct);
     if (ret != 0) {
         if (ide_handle_rw_error(s, -ret, IDE_RETRY_PIO |
@@ -677,6 +680,9 @@ void ide_dma_cb(void *opaque, int ret)
     int64_t sector_num;
     bool stay_active = false;
 
+    if (ret == -ECANCELED) {
+        return;
+    }
     if (ret < 0) {
         int op = IDE_RETRY_DMA;
 
@@ -802,6 +808,9 @@ static void ide_sector_write_cb(void *opaque, int ret)
     IDEState *s = opaque;
     int n;
 
+    if (ret == -ECANCELED) {
+        return;
+    }
     bdrv_acct_done(s->bs, &s->acct);
 
     s->pio_aiocb = NULL;
@@ -880,6 +889,9 @@ static void ide_flush_cb(void *opaque, int ret)
 
     s->pio_aiocb = NULL;
 
+    if (ret == -ECANCELED) {
+        return;
+    }
     if (ret < 0) {
         /* XXX: What sector number to set here? */
         if (ide_handle_rw_error(s, -ret, IDE_RETRY_FLUSH)) {
-- 
1.9.3