block: bdrv_aio_* do not return NULL

Initially done with the following semantic patch:

@ rule1 @
expression E;
statement S;
@@
  E =
(
   bdrv_aio_readv
|  bdrv_aio_writev
|  bdrv_aio_flush
|  bdrv_aio_discard
|  bdrv_aio_ioctl
)
     (...);
(
- if (E == NULL) { ... }
|
- if (E)
    { <... S ...> }
)

which however missed the occurrence in block/blkverify.c
(as it should have done), and left behind some unused
variables.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

4 files changed, 31 insertions, 95 deletions

diff --git a/block/blkverify.c b/block/blkverify.c
index 483f3b3..4ca8584 100644
--- a/block/blkverify.c
+++ b/block/blkverify.c
@@ -310,14 +310,10 @@ static BlockDriverAIOCB *blkverify_aio_readv(BlockDriverState *bs,
     qemu_iovec_init(&acb->raw_qiov, acb->qiov->niov);
     blkverify_iovec_clone(&acb->raw_qiov, qiov, acb->buf);
 
-    if (!bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors,
-                        blkverify_aio_cb, acb)) {
-        blkverify_aio_cb(acb, -EIO);
-    }
-    if (!bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors,
-                        blkverify_aio_cb, acb)) {
-        blkverify_aio_cb(acb, -EIO);
-    }
+    bdrv_aio_readv(s->test_file, sector_num, qiov, nb_sectors,
+                   blkverify_aio_cb, acb);
+    bdrv_aio_readv(bs->file, sector_num, &acb->raw_qiov, nb_sectors,
+                   blkverify_aio_cb, acb);
     return &acb->common;
 }
 
@@ -329,14 +325,10 @@ static BlockDriverAIOCB *blkverify_aio_writev(BlockDriverState *bs,
     BlkverifyAIOCB *acb = blkverify_aio_get(bs, true, sector_num, qiov,
                                             nb_sectors, cb, opaque);
 
-    if (!bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors,
-                         blkverify_aio_cb, acb)) {
-        blkverify_aio_cb(acb, -EIO);
-    }
-    if (!bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors,
-                         blkverify_aio_cb, acb)) {
-        blkverify_aio_cb(acb, -EIO);
-    }
+    bdrv_aio_writev(s->test_file, sector_num, qiov, nb_sectors,
+                    blkverify_aio_cb, acb);
+    bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors,
+                    blkverify_aio_cb, acb);
     return &acb->common;
 }
 
diff --git a/block/qed-table.c b/block/qed-table.c
index 8ee8443..ce07b05 100644
--- a/block/qed-table.c
+++ b/block/qed-table.c
@@ -54,7 +54,6 @@ static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     QEDReadTableCB *read_table_cb = gencb_alloc(sizeof(*read_table_cb),
                                                 cb, opaque);
     QEMUIOVector *qiov = &read_table_cb->qiov;
-    BlockDriverAIOCB *aiocb;
 
     trace_qed_read_table(s, offset, table);
 
@@ -64,12 +63,9 @@ static void qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     read_table_cb->iov.iov_len = s->header.cluster_size * s->header.table_size,
 
     qemu_iovec_init_external(qiov, &read_table_cb->iov, 1);
-    aiocb = bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
-                           qiov->size / BDRV_SECTOR_SIZE,
-                           qed_read_table_cb, read_table_cb);
-    if (!aiocb) {
-        qed_read_table_cb(read_table_cb, -EIO);
-    }
+    bdrv_aio_readv(s->bs->file, offset / BDRV_SECTOR_SIZE, qiov,
+                   qiov->size / BDRV_SECTOR_SIZE,
+                   qed_read_table_cb, read_table_cb);
 }
 
 typedef struct {
@@ -127,7 +123,6 @@ static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
                             BlockDriverCompletionFunc *cb, void *opaque)
 {
     QEDWriteTableCB *write_table_cb;
-    BlockDriverAIOCB *aiocb;
     unsigned int sector_mask = BDRV_SECTOR_SIZE / sizeof(uint64_t) - 1;
     unsigned int start, end, i;
     size_t len_bytes;
@@ -158,13 +153,10 @@ static void qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     /* Adjust for offset into table */
     offset += start * sizeof(uint64_t);
 
-    aiocb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
-                            &write_table_cb->qiov,
-                            write_table_cb->qiov.size / BDRV_SECTOR_SIZE,
-                            qed_write_table_cb, write_table_cb);
-    if (!aiocb) {
-        qed_write_table_cb(write_table_cb, -EIO);
-    }
+    bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
+                    &write_table_cb->qiov,
+                    write_table_cb->qiov.size / BDRV_SECTOR_SIZE,
+                    qed_write_table_cb, write_table_cb);
 }
 
 /**
diff --git a/block/qed.c b/block/qed.c
index 22e4672..8da3ebe 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -123,7 +123,6 @@ static void qed_write_header_read_cb(void *opaque, int ret)
 {
     QEDWriteHeaderCB *write_header_cb = opaque;
     BDRVQEDState *s = write_header_cb->s;
-    BlockDriverAIOCB *acb;
 
     if (ret) {
         qed_write_header_cb(write_header_cb, ret);
@@ -133,12 +132,9 @@ static void qed_write_header_read_cb(void *opaque, int ret)
     /* Update header */
     qed_header_cpu_to_le(&s->header, (QEDHeader *)write_header_cb->buf);
 
-    acb = bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov,
-                          write_header_cb->nsectors, qed_write_header_cb,
-                          write_header_cb);
-    if (!acb) {
-        qed_write_header_cb(write_header_cb, -EIO);
-    }
+    bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov,
+                    write_header_cb->nsectors, qed_write_header_cb,
+                    write_header_cb);
 }
 
 /**
@@ -156,7 +152,6 @@ static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb,
      * them, and write back.
      */
 
-    BlockDriverAIOCB *acb;
     int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) /
                    BDRV_SECTOR_SIZE;
     size_t len = nsectors * BDRV_SECTOR_SIZE;
@@ -170,11 +165,8 @@ static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb,
     write_header_cb->iov.iov_len = len;
     qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1);
 
-    acb = bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors,
-                         qed_write_header_read_cb, write_header_cb);
-    if (!acb) {
-        qed_write_header_cb(write_header_cb, -EIO);
-    }
+    bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors,
+                   qed_write_header_read_cb, write_header_cb);
 }
 
 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
@@ -728,7 +720,6 @@ static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
                                   QEMUIOVector *qiov,
                                   BlockDriverCompletionFunc *cb, void *opaque)
 {
-    BlockDriverAIOCB *aiocb;
     uint64_t backing_length = 0;
     size_t size;
 
@@ -760,11 +751,8 @@ static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
     size = MIN((uint64_t)backing_length - pos, qiov->size);
 
     BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING);
-    aiocb = bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE,
-                           qiov, size / BDRV_SECTOR_SIZE, cb, opaque);
-    if (!aiocb) {
-        cb(opaque, -EIO);
-    }
+    bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE,
+                   qiov, size / BDRV_SECTOR_SIZE, cb, opaque);
 }
 
 typedef struct {
@@ -786,7 +774,6 @@ static void qed_copy_from_backing_file_write(void *opaque, int ret)
 {
     CopyFromBackingFileCB *copy_cb = opaque;
     BDRVQEDState *s = copy_cb->s;
-    BlockDriverAIOCB *aiocb;
 
     if (ret) {
         qed_copy_from_backing_file_cb(copy_cb, ret);
@@ -794,13 +781,9 @@ static void qed_copy_from_backing_file_write(void *opaque, int ret)
     }
 
     BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
-    aiocb = bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE,
-                            &copy_cb->qiov,
-                            copy_cb->qiov.size / BDRV_SECTOR_SIZE,
-                            qed_copy_from_backing_file_cb, copy_cb);
-    if (!aiocb) {
-        qed_copy_from_backing_file_cb(copy_cb, -EIO);
-    }
+    bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE,
+                    &copy_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE,
+                    qed_copy_from_backing_file_cb, copy_cb);
 }
 
 /**
@@ -1022,7 +1005,6 @@ static void qed_aio_write_main(void *opaque, int ret)
     uint64_t offset = acb->cur_cluster +
                       qed_offset_into_cluster(s, acb->cur_pos);
     BlockDriverCompletionFunc *next_fn;
-    BlockDriverAIOCB *file_acb;
 
     trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size);
 
@@ -1042,13 +1024,9 @@ static void qed_aio_write_main(void *opaque, int ret)
     }
 
     BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);
-    file_acb = bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
-                               &acb->cur_qiov,
-                               acb->cur_qiov.size / BDRV_SECTOR_SIZE,
-                               next_fn, acb);
-    if (!file_acb) {
-        qed_aio_complete(acb, -EIO);
-    }
+    bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE,
+                    &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE,
+                    next_fn, acb);
 }
 
 /**
@@ -1215,7 +1193,6 @@ static void qed_aio_read_data(void *opaque, int ret,
     QEDAIOCB *acb = opaque;
     BDRVQEDState *s = acb_to_s(acb);
     BlockDriverState *bs = acb->common.bs;
-    BlockDriverAIOCB *file_acb;
 
     /* Adjust offset into cluster */
     offset += qed_offset_into_cluster(s, acb->cur_pos);
@@ -1240,14 +1217,9 @@ static void qed_aio_read_data(void *opaque, int ret,
     }
 
     BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
-    file_acb = bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE,
-                              &acb->cur_qiov,
-                              acb->cur_qiov.size / BDRV_SECTOR_SIZE,
-                              qed_aio_next_io, acb);
-    if (!file_acb) {
-        ret = -EIO;
-        goto err;
-    }
+    bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE,
+                   &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE,
+                   qed_aio_next_io, acb);
     return;
 
 err:
diff --git a/block/vdi.c b/block/vdi.c
index e1d8cff..6bb43b8 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -633,10 +633,6 @@ static void vdi_aio_read_cb(void *opaque, int ret)
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
         acb->hd_aiocb = bdrv_aio_readv(bs->file, offset, &acb->hd_qiov,
                                        n_sectors, vdi_aio_read_cb, acb);
-        if (acb->hd_aiocb == NULL) {
-            ret = -EIO;
-            goto done;
-        }
     }
     return;
 done:
@@ -708,10 +704,6 @@ static void vdi_aio_write_cb(void *opaque, int ret)
             qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
             acb->hd_aiocb = bdrv_aio_writev(bs->file, 0, &acb->hd_qiov, 1,
                                             vdi_aio_write_cb, acb);
-            if (acb->hd_aiocb == NULL) {
-                ret = -EIO;
-                goto done;
-            }
             return;
         } else if (VDI_IS_ALLOCATED(acb->bmap_first)) {
             /* One or more new blocks were allocated. */
@@ -738,10 +730,6 @@ static void vdi_aio_write_cb(void *opaque, int ret)
                    n_sectors, bmap_first);
             acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
                                             n_sectors, vdi_aio_write_cb, acb);
-            if (acb->hd_aiocb == NULL) {
-                ret = -EIO;
-                goto done;
-            }
             return;
         }
         ret = 0;
@@ -789,10 +777,6 @@ static void vdi_aio_write_cb(void *opaque, int ret)
         acb->hd_aiocb = bdrv_aio_writev(bs->file, offset,
                                         &acb->hd_qiov, s->block_sectors,
                                         vdi_aio_write_cb, acb);
-        if (acb->hd_aiocb == NULL) {
-            ret = -EIO;
-            goto done;
-        }
     } else {
         uint64_t offset = s->header.offset_data / SECTOR_SIZE +
                           (uint64_t)bmap_entry * s->block_sectors +
@@ -802,10 +786,6 @@ static void vdi_aio_write_cb(void *opaque, int ret)
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
         acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov,
                                         n_sectors, vdi_aio_write_cb, acb);
-        if (acb->hd_aiocb == NULL) {
-            ret = -EIO;
-            goto done;
-        }
     }
 
     return;