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Diffstat (limited to 'block/io.c')
-rw-r--r--block/io.c101
1 files changed, 72 insertions, 29 deletions
diff --git a/block/io.c b/block/io.c
index 5518a9d..34b30e3 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1130,8 +1130,7 @@ static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
int ret;
bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort);
- assert(!(flags & ~BDRV_REQ_MASK));
- assert(!(flags & BDRV_REQ_NO_FALLBACK));
+ assert(!(flags & ~bs->supported_read_flags));
if (!drv) {
return -ENOMEDIUM;
@@ -1195,23 +1194,29 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
BdrvRequestFlags flags)
{
BlockDriver *drv = bs->drv;
+ bool emulate_fua = false;
int64_t sector_num;
unsigned int nb_sectors;
QEMUIOVector local_qiov;
int ret;
bdrv_check_qiov_request(offset, bytes, qiov, qiov_offset, &error_abort);
- assert(!(flags & ~BDRV_REQ_MASK));
- assert(!(flags & BDRV_REQ_NO_FALLBACK));
if (!drv) {
return -ENOMEDIUM;
}
+ if ((flags & BDRV_REQ_FUA) &&
+ (~bs->supported_write_flags & BDRV_REQ_FUA)) {
+ flags &= ~BDRV_REQ_FUA;
+ emulate_fua = true;
+ }
+
+ flags &= bs->supported_write_flags;
+
if (drv->bdrv_co_pwritev_part) {
ret = drv->bdrv_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset,
- flags & bs->supported_write_flags);
- flags &= ~bs->supported_write_flags;
+ flags);
goto emulate_flags;
}
@@ -1221,9 +1226,7 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
}
if (drv->bdrv_co_pwritev) {
- ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov,
- flags & bs->supported_write_flags);
- flags &= ~bs->supported_write_flags;
+ ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, flags);
goto emulate_flags;
}
@@ -1233,10 +1236,8 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
.coroutine = qemu_coroutine_self(),
};
- acb = drv->bdrv_aio_pwritev(bs, offset, bytes, qiov,
- flags & bs->supported_write_flags,
+ acb = drv->bdrv_aio_pwritev(bs, offset, bytes, qiov, flags,
bdrv_co_io_em_complete, &co);
- flags &= ~bs->supported_write_flags;
if (acb == NULL) {
ret = -EIO;
} else {
@@ -1254,12 +1255,10 @@ static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
assert(bytes <= BDRV_REQUEST_MAX_BYTES);
assert(drv->bdrv_co_writev);
- ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov,
- flags & bs->supported_write_flags);
- flags &= ~bs->supported_write_flags;
+ ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov, flags);
emulate_flags:
- if (ret == 0 && (flags & BDRV_REQ_FUA)) {
+ if (ret == 0 && emulate_fua) {
ret = bdrv_co_flush(bs);
}
@@ -1487,11 +1486,14 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
max_transfer = QEMU_ALIGN_DOWN(MIN_NON_ZERO(bs->bl.max_transfer, INT_MAX),
align);
- /* TODO: We would need a per-BDS .supported_read_flags and
+ /*
+ * TODO: We would need a per-BDS .supported_read_flags and
* potential fallback support, if we ever implement any read flags
* to pass through to drivers. For now, there aren't any
- * passthrough flags. */
- assert(!(flags & ~(BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH)));
+ * passthrough flags except the BDRV_REQ_REGISTERED_BUF optimization hint.
+ */
+ assert(!(flags & ~(BDRV_REQ_COPY_ON_READ | BDRV_REQ_PREFETCH |
+ BDRV_REQ_REGISTERED_BUF)));
/* Handle Copy on Read and associated serialisation */
if (flags & BDRV_REQ_COPY_ON_READ) {
@@ -1532,7 +1534,7 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child,
goto out;
}
- assert(!(flags & ~bs->supported_read_flags));
+ assert(!(flags & ~(bs->supported_read_flags | BDRV_REQ_REGISTERED_BUF)));
max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align);
if (bytes <= max_bytes && bytes <= max_transfer) {
@@ -1721,7 +1723,8 @@ static void bdrv_padding_destroy(BdrvRequestPadding *pad)
static int bdrv_pad_request(BlockDriverState *bs,
QEMUIOVector **qiov, size_t *qiov_offset,
int64_t *offset, int64_t *bytes,
- BdrvRequestPadding *pad, bool *padded)
+ BdrvRequestPadding *pad, bool *padded,
+ BdrvRequestFlags *flags)
{
int ret;
@@ -1749,6 +1752,10 @@ static int bdrv_pad_request(BlockDriverState *bs,
if (padded) {
*padded = true;
}
+ if (flags) {
+ /* Can't use optimization hint with bounce buffer */
+ *flags &= ~BDRV_REQ_REGISTERED_BUF;
+ }
return 0;
}
@@ -1803,7 +1810,7 @@ int coroutine_fn bdrv_co_preadv_part(BdrvChild *child,
}
ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad,
- NULL);
+ NULL, &flags);
if (ret < 0) {
goto fail;
}
@@ -1848,6 +1855,11 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
return -ENOTSUP;
}
+ /* By definition there is no user buffer so this flag doesn't make sense */
+ if (flags & BDRV_REQ_REGISTERED_BUF) {
+ return -EINVAL;
+ }
+
/* Invalidate the cached block-status data range if this write overlaps */
bdrv_bsc_invalidate_range(bs, offset, bytes);
@@ -2133,6 +2145,9 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child,
bool padding;
BdrvRequestPadding pad;
+ /* This flag doesn't make sense for padding or zero writes */
+ flags &= ~BDRV_REQ_REGISTERED_BUF;
+
padding = bdrv_init_padding(bs, offset, bytes, &pad);
if (padding) {
assert(!(flags & BDRV_REQ_NO_WAIT));
@@ -2250,7 +2265,7 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child,
* alignment only if there is no ZERO flag.
*/
ret = bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad,
- &padded);
+ &padded, &flags);
if (ret < 0) {
return ret;
}
@@ -3262,29 +3277,57 @@ void bdrv_io_unplug(BlockDriverState *bs)
}
}
-void bdrv_register_buf(BlockDriverState *bs, void *host, size_t size)
+/* Helper that undoes bdrv_register_buf() when it fails partway through */
+static void bdrv_register_buf_rollback(BlockDriverState *bs,
+ void *host,
+ size_t size,
+ BdrvChild *final_child)
+{
+ BdrvChild *child;
+
+ QLIST_FOREACH(child, &bs->children, next) {
+ if (child == final_child) {
+ break;
+ }
+
+ bdrv_unregister_buf(child->bs, host, size);
+ }
+
+ if (bs->drv && bs->drv->bdrv_unregister_buf) {
+ bs->drv->bdrv_unregister_buf(bs, host, size);
+ }
+}
+
+bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
+ Error **errp)
{
BdrvChild *child;
GLOBAL_STATE_CODE();
if (bs->drv && bs->drv->bdrv_register_buf) {
- bs->drv->bdrv_register_buf(bs, host, size);
+ if (!bs->drv->bdrv_register_buf(bs, host, size, errp)) {
+ return false;
+ }
}
QLIST_FOREACH(child, &bs->children, next) {
- bdrv_register_buf(child->bs, host, size);
+ if (!bdrv_register_buf(child->bs, host, size, errp)) {
+ bdrv_register_buf_rollback(bs, host, size, child);
+ return false;
+ }
}
+ return true;
}
-void bdrv_unregister_buf(BlockDriverState *bs, void *host)
+void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size)
{
BdrvChild *child;
GLOBAL_STATE_CODE();
if (bs->drv && bs->drv->bdrv_unregister_buf) {
- bs->drv->bdrv_unregister_buf(bs, host);
+ bs->drv->bdrv_unregister_buf(bs, host, size);
}
QLIST_FOREACH(child, &bs->children, next) {
- bdrv_unregister_buf(child->bs, host);
+ bdrv_unregister_buf(child->bs, host, size);
}
}
generated by cgit v1.1 at 2025-01-12 18:08:41 +0000