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2016-09-29block: reintroduce bdrv_flush_allJohn Snow
Commit fe1a9cbc moved the flush_all routine from the bdrv layer to the block-backend layer. In doing so, however, the semantics of the routine changed slightly such that flush_all now used blk_flush instead of bdrv_flush. blk_flush can fail if the attached device model reports that it is not "available," (i.e. the tray is open.) This changed the semantics of flush_all such that it can now fail for e.g. open CDROM drives. Reintroduce bdrv_flush_all to regain the old semantics without having to alter the behavior of blk_flush or blk_flush_all, which are already 'doing the right thing.' Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block/io: turn on dirty_bitmaps for the compressed writesPavel Butsykin
Previously was added the assert: commit 1755da16e32c15b22a521e8a38539e4b5cf367f3 Author: Paolo Bonzini <pbonzini@redhat.com> Date: Thu Oct 18 16:49:18 2012 +0200 block: introduce new dirty bitmap functionality Now the compressed write is always in coroutine and setting the bits is done after the write, so that we can return the dirty_bitmaps for the compressed writes. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: remove BlockDriver.bdrv_write_compressedPavel Butsykin
There are no block drivers left that implement the old .bdrv_write_compressed interface, so it can be removed. Also now we have no need to use the bdrv_pwrite_compressed function and we can remove it entirely. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block/io: reuse bdrv_co_pwritev() for write compressedPavel Butsykin
For bdrv_pwrite_compressed() it looks like most of the code creating coroutine is duplicated in bdrv_prwv_co(). So we can just add a flag (BDRV_REQ_WRITE_COMPRESSED) and use bdrv_prwv_co() as a generic one. In the end we get coroutine oriented function for write compressed by using bdrv_co_pwritev/blk_co_pwritev with BDRV_REQ_WRITE_COMPRESSED flag. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: Convert bdrv_pwrite_compressed() to BdrvChildPavel Butsykin
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Eric Blake <eblake@redhat.com> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block: switch blk_write_compressed() to byte-based interfacePavel Butsykin
This is a preparatory patch, which continues the general trend of the transition to the byte-based interfaces. bdrv_check_request() and blk_check_request() are no longer used, thus we can remove them. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Jeff Cody <jcody@redhat.com> CC: Markus Armbruster <armbru@redhat.com> CC: Eric Blake <eblake@redhat.com> CC: John Snow <jsnow@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-08-18block: fix possible reorder of flush operationsDenis V. Lunev
This patch reduce CPU usage of flush operations a bit. When we have one flush completed we should kick only next operation. We should not start all pending operations in the hope that they will go back to wait on wait_queue. Also there is a technical possibility that requests will get reordered with the previous approach. After wakeup all requests are removed from the wait queue. They become active and they are processed one-by-one adding to the wait queue in the same order. Though new flush can arrive while all requests are not put into the queue. Signed-off-by: Denis V. Lunev <den@openvz.org> Tested-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Message-id: 1471457214-3994-3-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-18block: fix deadlock in bdrv_co_flushEvgeny Yakovlev
The following commit commit 3ff2f67a7c24183fcbcfe1332e5223ac6f96438c Author: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Date: Mon Jul 18 22:39:52 2016 +0300 block: ignore flush requests when storage is clean has introduced a regression. There is a problem that it is still possible for 2 requests to execute in non sequential fashion and sometimes this results in a deadlock when bdrv_drain_one/all are called for BDS with such stalled requests. 1. Current flushed_gen and flush_started_gen is 1. 2. Request 1 enters bdrv_co_flush to with write_gen 1 (i.e. the same as flushed_gen). It gets past flushed_gen != flush_started_gen and sets flush_started_gen to 1 (again, the same it was before). 3. Request 1 yields somewhere before exiting bdrv_co_flush 4. Request 2 enters bdrv_co_flush with write_gen 2. It gets past flushed_gen != flush_started_gen and sets flush_started_gen to 2. 5. Request 2 runs to completion and sets flushed_gen to 2 6. Request 1 is resumed, runs to completion and sets flushed_gen to 1. However flush_started_gen is now 2. From here on out flushed_gen is always != to flush_started_gen and all further requests will wait on flush_queue. This change replaces flush_started_gen with an explicitly tracked active flush request. Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Message-id: 1471457214-3994-2-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-08-03block: Cater to iscsi with non-power-of-2 discardEric Blake
Dell Equallogic iSCSI SANs have a very unusual advertised geometry: $ iscsi-inq -e 1 -c $((0xb0)) iscsi://XXX/0 wsnz:0 maximum compare and write length:1 optimal transfer length granularity:0 maximum transfer length:0 optimal transfer length:0 maximum prefetch xdread xdwrite transfer length:0 maximum unmap lba count:30720 maximum unmap block descriptor count:2 optimal unmap granularity:30720 ugavalid:1 unmap granularity alignment:0 maximum write same length:30720 which says that both the maximum and the optimal discard size is 15M. It is not immediately apparent if the device allows discard requests not aligned to the optimal size, nor if it allows discards at a finer granularity than the optimal size. I tried to find details in the SCSI Commands Reference Manual Rev. A on what valid values of maximum and optimal sizes are permitted, but while that document mentions a "Block Limits VPD Page", I couldn't actually find documentation of that page or what values it would have, or if a SCSI device has an advertisement of its minimal unmap granularity. So it is not obvious to me whether the Dell Equallogic device is compliance with the SCSI specification. Fortunately, it is easy enough to support non-power-of-2 sizing, even if it means we are less efficient than truly possible when targetting that device (for example, it means that we refuse to unmap anything that is not a multiple of 15M and aligned to a 15M boundary, even if the device truly does support a smaller granularity where unmapping actually works). Reported-by: Peter Lieven <pl@kamp.de> Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <1469129688-22848-5-git-send-email-eblake@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-20block: Kill .bdrv_co_discard()Eric Blake
Now that all drivers have a byte-based .bdrv_co_pdiscard(), we no longer need to worry about the sector-based version. We can also relax our minimum alignment to 1 for drivers that support it. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-18-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Add .bdrv_co_pdiscard() driver callbackEric Blake
There's enough drivers with a sector-based callback that it will be easier to switch one at a time. This patch adds a byte-based callback, and then after all drivers are swapped, we'll drop the sector-based callback. [checkpatch doesn't like the space after coroutine_fn in block_int.h, but it's consistent with the rest of the file] Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-10-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert .bdrv_aio_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based driver callback .bdrv_aio_discard() with a new byte-based .bdrv_aio_pdiscard(). Only raw-posix and RBD drivers are affected, so it was not worth splitting into multiple patches. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-9-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_aio_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_aio_discard() with a new byte-based bdrv_aio_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468624988-423-5-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Switch BlockRequest to byte-basedEric Blake
BlockRequest is the internal struct used by bdrv_aio_*. At the moment, all such calls were sector-based, but we will eventually convert to byte-based; start by changing the internal variables to be byte-based. No change to behavior, although the read and write code can now go byte-based through more of the stack. Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468624988-423-4-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_discard() with a new byte-based bdrv_pdiscard(), which silently ignores any unaligned head or tail. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-3-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Convert bdrv_co_discard() to byte-basedEric Blake
Another step towards byte-based interfaces everywhere. Replace the sector-based bdrv_co_discard() with a new byte-based bdrv_co_pdiscard(), which silently ignores any unaligned head or tail. Driver callbacks will be converted in followup patches. By calculating the alignment outside of the loop, and clamping the max discard to an aligned value, we can simplify the actions done within the loop. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-2-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Fragment writes to max transfer lengthEric Blake
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). We already fragment write zeroes at the block layer; this patch adds the fragmentation for normal writes, after requests have been aligned (fragmenting before alignment would lead to multiple unaligned requests, rather than just the head and tail). When fragmenting a large request where FUA was requested, but where we know that FUA is implemented by flushing all requests rather than the given request, then we can still get by with only one flush. Note, however, that we need a followup patch to the raw format driver to avoid a regression in the number of flushes actually issued. The return value was previously nebulous on success (sometimes zero, sometimes the length written); since we never have a short write, and since fragmenting may store yet another positive value in 'ret', change the function to always return 0 on success, matching what we do in bdrv_aligned_preadv(). Signed-off-by: Eric Blake <eblake@redhat.com> Message-id: 1468607524-19021-4-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20block: Fragment reads to max transfer lengthEric Blake
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>
2016-07-18block: ignore flush requests when storage is cleanEvgeny Yakovlev
Some guests (win2008 server for example) do a lot of unnecessary flushing when underlying media has not changed. This adds additional overhead on host when calling fsync/fdatasync. This change introduces a write generation scheme in BlockDriverState. Current write generation is checked against last flushed generation to avoid unnessesary flushes. The problem with excessive flushing was found by a performance test which does parallel directory tree creation (from 2 processes). Results improved from 0.424 loops/sec to 0.432 loops/sec. Each loop creates 10^3 directories with 10 files in each. This affected some blkdebug testcases that were expecting error logs from failure-injected flushes which are now skipped entirely (tests 026 071 089). This also affects the performance of block jobs and thus BLOCK_JOB_READY events for driver-mirror and active block-commit commands now arrives faster, before QMP send successfully returns to caller (tests 141 144). Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468870792-7411-5-git-send-email-den@openvz.org CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Fam Zheng <famz@redhat.com> CC: John Snow <jsnow@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Convert bdrv_co_preadv/pwritev to BdrvChildKevin Wolf
This is the final patch for converting the common I/O path to take a BdrvChild parameter instead of BlockDriverState. The completion of this conversion means that all users that perform I/O on an image need to actually hold a reference (in the form of BdrvChild, possible as part of a BlockBackend) to that image. This also protects against inconsistent use of BlockBackend vs. BlockDriverState functions because direct use of a BlockDriverState isn't possible any more and blk->root is private for block-backends.c. In addition, we can now distinguish different users in the I/O path, and the future op blockers work is going to add assertions based on permissions stored in BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_prwv_co() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite_zeroes() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pwrite(v/_sync) to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_pread(v) to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_write() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_read() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_co_do_readv/writev to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_aio_writev() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_aio_readv() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_co_writev() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Convert bdrv_co_readv() to BdrvChildKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05block: Move request_alignment into BlockLimitEric Blake
It makes more sense to have ALL block size limit constraints in the same struct. Improve the documentation while at it. Simplify a couple of conditionals, now that we have audited and documented that request_alignment is always non-zero. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Split bdrv_merge_limits() from bdrv_refresh_limits()Eric Blake
During bdrv_merge_limits(), we were computing initial limits based on another BDS in two places. At first glance, the two computations are not identical (one is doing straight copying, the other is doing merging towards or away from zero) - but when you realize that the first round is starting with all-0 memory, all of the merging happens to work. Factoring out the merging makes it easier to track how two BDS limits are merged, in case we have future reasons to merge in even more limits. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Switch discard length bounds to byte-basedEric Blake
Sector-based limits are awkward to think about; in our on-going quest to move to byte-based interfaces, convert max_discard and discard_alignment. Rename them, using 'pdiscard' as an aid to track which remaining discard interfaces need conversion, and so that the compiler will help us catch the change in semantics across any rebased code. The BlockLimits type is now completely byte-based; and in iscsi.c, sector_limits_lun2qemu() is no longer needed. pdiscard_alignment is made unsigned (we use power-of-2 alignments as bitmasks, where unsigned is easier to think about) while leaving max_pdiscard signed (since we still have an 'int' interface); this is comparable to what commit cf081fc did for write zeroes limits. We may later want to make everything an unsigned 64-bit limit - but that requires a bigger code audit. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Switch transfer length bounds to byte-basedEric Blake
Sector-based limits are awkward to think about; in our on-going quest to move to byte-based interfaces, convert max_transfer_length and opt_transfer_length. Rename them (dropping the _length suffix) so that the compiler will help us catch the change in semantics across any rebased code, and improve the documentation. Use unsigned values, so that we don't have to worry about negative values and so that bit-twiddling is easier; however, we are still constrained by 2^31 of signed int in most APIs. When a value comes from an external source (iscsi and raw-posix), sanitize the results to ensure that opt_transfer is a power of 2. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Set default request_alignment during bdrv_refresh_limits()Eric Blake
We want to eventually stick request_alignment alongside other BlockLimits, but first, we must ensure it is populated at the same time as all other limits, rather than being a special case that is set only when a block is first opened. Now that all drivers have been updated to supply an override of request_alignment during their .bdrv_refresh_limits(), as needed, the block layer itself can defer setting the default alignment until part of the overall bdrv_refresh_limits(). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Fix harmless off-by-one in bdrv_aligned_preadv()Eric Blake
If the amount of data to read ends exactly on the total size of the bs, then we were wasting time creating a local qiov to read the data in preparation for what would normally be appending zeroes beyond the end, even though this corner case has nothing further to do. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Document supported flags during bdrv_aligned_preadv()Eric Blake
We don't pass any flags on to drivers to handle. Tighten an assert to explain why we pass 0 to bdrv_driver_preadv(), and add some comments on things to be aware of if we want to turn on per-BDS BDRV_REQ_FUA support during reads in the future. Also, document that we may want to consider using unmap during copy-on-read operations where the read is all zeroes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05block: Tighter assertions on bdrv_aligned_pwritev()Eric Blake
For symmetry with bdrv_aligned_preadv(), assert that the caller really has aligned things properly. This requires adding an align parameter, which is used now only in the new asserts, but will come in handy in a later patch that adds auto-fragmentation to the max transfer size, since that value need not always be a multiple of the alignment, and therefore must be rounded down. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-20block: process before_write_notifiers in bdrv_co_discardDenis V. Lunev
This is mandatory for correct backup creation. In the other case the content under this area would be lost. Dirty bits are set exactly like in bdrv_aligned_pwritev, i.e. they are set even if notifier has returned a error. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1466093381-6120-4-git-send-email-den@openvz.org CC: Fam Zheng <famz@redhat.com> CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20block: fix race in bdrv_co_discard with drive-mirrorDenis V. Lunev
Actually we must set dirty bitmap dirty after we have written all our zeroes for correct processing in drive mirror code. In the other case we can face not zeroes in this area in mirror_iteration. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1466093381-6120-3-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-20block: fixed BdrvTrackedRequest filling in bdrv_co_discardDenis V. Lunev
The request area is specified in bytes, not in sectors. Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1466093381-6120-2-git-send-email-den@openvz.org CC: Stefan Hajnoczi <stefanha@redhat.com> CC: Kevin Wolf <kwolf@redhat.com> CC: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16block: use the block job list in bdrv_drain_all()Alberto Garcia
bdrv_drain_all() pauses all block jobs by using bdrv_next() to iterate over all top-level BlockDriverStates. Therefore the code is unable to find block jobs in other nodes. This patch uses block_job_next() to iterate over all block jobs. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: 55ee7d7d4a65c28aa1a1b28823897ef326f328e2.1464346103.git.berto@igalia.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16block: Remove bs->zero_beyond_eofKevin Wolf
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>
2016-06-16block: Make bdrv_load/save_vmstate coroutine_fnsKevin Wolf
This allows drivers to share code between normal I/O and vmstate accesses. 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>
2016-06-16block: Allow .bdrv_load/save_vmstate() to return 0/-errnoKevin Wolf
The return value of .bdrv_load/save_vmstate() can be any non-negative number in case of success now. It used to be bytes/-errno. 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>
2016-06-16block: Make .bdrv_load_vmstate() vectoredKevin Wolf
This brings it in line with .bdrv_save_vmstate(). 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>
2016-06-16block: Introduce bdrv_preadv()Kevin Wolf
We already have a byte-based bdrv_pwritev(), but the read counterpart was still missing. This commit adds it. 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>
2016-06-16block: Don't enforce 512 byte minimum alignmentKevin Wolf
If block drivers say that they can do an alignment < 512 bytes, let's just suppose they mean it. raw-posix used to be an offender with respect to this, but it can actually deal with byte-aligned requests now. The default is still 512 bytes for any drivers that only implement sector-based interfaces, but it is 1 now for drivers that implement .bdrv_co_preadv. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>