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block: Remove bs->zero_beyond_eof

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It is always true for open images now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Kevin Wolf 2016-06-01 17:13:47 +02:00
parent 734a77584a
commit c9d20029f4
3 changed files with 25 additions and 36 deletions
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2
block.c
View file

@ -938,7 +938,6 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
}
bs->request_alignment = drv->bdrv_co_preadv ? 1 : 512;
bs->zero_beyond_eof = true;
bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
@ -2192,7 +2191,6 @@ static void bdrv_close(BlockDriverState *bs)
bs->encrypted = 0;
bs->valid_key = 0;
bs->sg = 0;
bs->zero_beyond_eof = false;
QDECREF(bs->options);
QDECREF(bs->explicit_options);
bs->options = NULL;

56
block/io.c
View file

@ -967,6 +967,7 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
int64_t align, QEMUIOVector *qiov, int flags)
{
int64_t total_bytes, max_bytes;
int ret;
assert(is_power_of_2(align));
@ -1008,40 +1009,33 @@ static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
}
/* Forward the request to the BlockDriver */
if (!bs->zero_beyond_eof) {
total_bytes = bdrv_getlength(bs);
if (total_bytes < 0) {
ret = total_bytes;
goto out;
}
max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align);
if (bytes < max_bytes) {
ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
} else if (max_bytes > 0) {
QEMUIOVector local_qiov;
qemu_iovec_init(&local_qiov, qiov->niov);
qemu_iovec_concat(&local_qiov, qiov, 0, max_bytes);
ret = bdrv_driver_preadv(bs, offset, max_bytes, &local_qiov, 0);
qemu_iovec_destroy(&local_qiov);
} else {
/* Read zeros after EOF */
int64_t total_bytes, max_bytes;
ret = 0;
}
total_bytes = bdrv_getlength(bs);
if (total_bytes < 0) {
ret = total_bytes;
goto out;
}
max_bytes = ROUND_UP(MAX(0, total_bytes - offset), align);
if (bytes < max_bytes) {
ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
} else if (max_bytes > 0) {
QEMUIOVector local_qiov;
qemu_iovec_init(&local_qiov, qiov->niov);
qemu_iovec_concat(&local_qiov, qiov, 0, max_bytes);
ret = bdrv_driver_preadv(bs, offset, max_bytes, &local_qiov, 0);
qemu_iovec_destroy(&local_qiov);
} else {
ret = 0;
}
/* Reading beyond end of file is supposed to produce zeroes */
if (ret == 0 && total_bytes < offset + bytes) {
uint64_t zero_offset = MAX(0, total_bytes - offset);
uint64_t zero_bytes = offset + bytes - zero_offset;
qemu_iovec_memset(qiov, zero_offset, 0, zero_bytes);
}
/* Reading beyond end of file is supposed to produce zeroes */
if (ret == 0 && total_bytes < offset + bytes) {
uint64_t zero_offset = MAX(0, total_bytes - offset);
uint64_t zero_bytes = offset + bytes - zero_offset;
qemu_iovec_memset(qiov, zero_offset, 0, zero_bytes);
}
out:

3
include/block/block_int.h
View file

@ -451,9 +451,6 @@ struct BlockDriverState {
/* I/O Limits */
BlockLimits bl;
/* Whether produces zeros when read beyond eof */
bool zero_beyond_eof;
/* Alignment requirement for offset/length of I/O requests */
unsigned int request_alignment;
/* Flags honored during pwrite (so far: BDRV_REQ_FUA) */