qemu/block
Eric Blake 1a62d0accd block: Fragment reads to max transfer length
Drivers should be able to rely on the block layer honoring the
max transfer length, rather than needing to return -EINVAL
(iscsi) or manually fragment things (nbd).  This patch adds
the fragmentation in the block layer, after requests have been
aligned (fragmenting before alignment would lead to multiple
unaligned requests, rather than just the head and tail).

The return value was previously nebulous on success on whether
it was zero or the length read; and fragmenting may introduce
yet other non-zero values if we use the last length read.  But
as at least some callers are sloppy and expect only zero on
success, it is easiest to just guarantee 0.

[Fix uninitialized ret local variable in bdrv_aligned_preadv().
--Stefan]

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1468607524-19021-2-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20 14:11:54 +01:00
..
accounting.c block: Clean up includes 2016-01-20 13:36:23 +01:00
archipelago.c coccinelle: Remove unnecessary variables for function return value 2016-06-20 16:38:13 +02:00
backup.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
blkdebug.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
blkreplay.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
blkverify.c block: Convert bdrv_aio_writev() to BdrvChild 2016-07-05 16:46:26 +02:00
block-backend.c block/qdev: Allow configuring rerror/werror with qdev properties 2016-07-13 13:32:27 +02:00
bochs.c block: Convert bdrv_co_preadv/pwritev to BdrvChild 2016-07-05 16:46:27 +02:00
cloop.c block: Convert bdrv_pread(v) to BdrvChild 2016-07-05 16:46:27 +02:00
commit.c Improve block job rate limiting for small bandwidth values 2016-07-13 13:41:38 +02:00
crypto.c QAPI patches for 2016-07-06 2016-07-06 11:38:09 +01:00
curl.c block: always compile-check debug prints 2016-05-12 15:22:08 +02:00
dirty-bitmap.c include/qemu/osdep.h: Don't include qapi/error.h 2016-03-22 22:20:15 +01:00
dmg.c block: Convert bdrv_pread(v) to BdrvChild 2016-07-05 16:46:27 +02:00
gluster.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
io.c block: Fragment reads to max transfer length 2016-07-20 14:11:54 +01:00
iscsi.c block/iscsi: allow caching of the allocation map 2016-07-19 08:34:53 +02:00
linux-aio.c linux-aio: prevent submitting more than MAX_EVENTS 2016-07-18 15:10:52 +01:00
Makefile.objs block: Move bdrv_commit() to block/commit.c 2016-07-05 16:46:27 +02:00
mirror.c Improve block job rate limiting for small bandwidth values 2016-07-13 13:41:38 +02:00
nbd-client.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
nbd-client.h nbd: Simplify client FUA handling 2016-05-12 15:22:09 +02:00
nbd.c block: Switch discard length bounds to byte-based 2016-07-05 16:46:25 +02:00
nfs.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
null.c block/null: Implement bdrv_refresh_filename() 2016-06-16 15:20:37 +02:00
parallels.c block: Convert bdrv_pwrite_zeroes() to BdrvChild 2016-07-05 16:46:27 +02:00
qapi.c qapi: Add new visit_complete() function 2016-07-06 10:52:04 +02:00
qcow2-cache.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
qcow2-cluster.c qcow2: Fix qcow2_get_cluster_offset() 2016-07-13 13:41:38 +02:00
qcow2-refcount.c block/qcow2: Don't use cpu_to_*w() 2016-07-05 16:54:04 +02:00
qcow2-snapshot.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
qcow2.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
qcow2.h qcow2: Implement .bdrv_co_pwritev() 2016-06-16 15:19:55 +02:00
qcow.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
qed-check.c qed: Use DIV_ROUND_UP 2016-06-07 18:19:24 +03:00
qed-cluster.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-gencb.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-l2-cache.c block: Clean up includes 2016-01-20 13:36:23 +01:00
qed-table.c block: Convert bdrv_aio_writev() to BdrvChild 2016-07-05 16:46:26 +02:00
qed.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
qed.h util: move declarations out of qemu-common.h 2016-03-22 22:20:17 +01:00
quorum.c block: Convert bdrv_aio_writev() to BdrvChild 2016-07-05 16:46:26 +02:00
raw_bsd.c block: Convert bdrv_co_preadv/pwritev to BdrvChild 2016-07-05 16:46:27 +02:00
raw-posix.c linux-aio: share one LinuxAioState within an AioContext 2016-07-18 15:09:31 +01:00
raw-win32.c linux-aio: share one LinuxAioState within an AioContext 2016-07-18 15:09:31 +01:00
rbd.c coccinelle: Remove unnecessary variables for function return value 2016-06-20 16:38:13 +02:00
sheepdog.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
snapshot.c error: Remove NULL checks on error_propagate() calls 2016-06-20 16:38:13 +02:00
ssh.c coroutine: move entry argument to qemu_coroutine_create 2016-07-13 13:26:02 +02:00
stream.c Improve block job rate limiting for small bandwidth values 2016-07-13 13:41:38 +02:00
throttle-groups.c block: Move I/O throttling configuration functions to BlockBackend 2016-05-19 16:45:30 +02:00
trace-events trace: split out trace events for block/ directory 2016-06-20 17:22:14 +01:00
vdi.c block: Convert bdrv_co_preadv/pwritev to BdrvChild 2016-07-05 16:46:27 +02:00
vhdx-endian.c qemu-common: stop including qemu/bswap.h from qemu-common.h 2016-05-19 16:42:28 +02:00
vhdx-log.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
vhdx.c block: Convert bdrv_pwrite(v/_sync) to BdrvChild 2016-07-05 16:46:27 +02:00
vhdx.h block: vhdx - update PAYLOAD_BLOCK_UNMAPPED value to match 1.00 spec 2014-12-12 15:42:22 +00:00
vmdk.c vmdk: fix metadata write regression 2016-07-13 13:41:39 +02:00
vpc.c block: Convert bdrv_co_preadv/pwritev to BdrvChild 2016-07-05 16:46:27 +02:00
vvfat.c vvfat: Fix qcow write target driver specification 2016-07-13 13:41:39 +02:00
win32-aio.c linux-aio: share one LinuxAioState within an AioContext 2016-07-18 15:09:31 +01:00
write-threshold.c block: Clean up includes 2016-01-20 13:36:23 +01:00