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2017-06-14block/iscsi: enable filename option and parsingJeff Cody
When enabling option parsing and blockdev-add for iscsi, we removed the 'filename' option. Unfortunately, this was a bit optimistic, as previous versions of QEMU allowed the use of the option in backing filenames via json. This means that without parsing this option, we cannot open existing images that used to work fine. See bug: https://bugzilla.redhat.com/show_bug.cgi?id=1457088 Tested-by: Richard W.M. Jones <rjones@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Message-id: 0789ab6c32814ab4b6896707d378804bd4424c65.1497444637.git.jcody@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-04-28block: Add .bdrv_truncate() error messagesMax Reitz
Add missing error messages for the block driver implementations of .bdrv_truncate(); drop the generic one from block.c's bdrv_truncate(). Since one of these changes touches a mis-indented block in block/file-posix.c, this patch fixes that coding style issue along the way. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-5-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28block: Add errp to BD.bdrv_truncate()Max Reitz
Add an Error parameter to the block drivers' bdrv_truncate() interface. If a block driver does not set this in case of an error, the generic bdrv_truncate() implementation will do so. Where it is obvious, this patch also makes some block drivers set this value. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-4-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-11iscsi: Fix iscsi_createFam Zheng
Since d5895fcb (iscsi: Split URL into individual options), creating qcow2 image on an iscsi LUN fails: qemu-img create -f qcow2 iscsi://$SERVER/$IQN/0 1G qemu-img: iscsi://$SERVER/$IQN/0: Could not create image: Invalid argument The problem is iscsi_open now expects that transport_name, portal and target are already parsed into structured options by iscsi_parse_filename, but it is not called in iscsi_create. Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 20170410075451.21329-1-famz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> [mreitz: Dropped now superfluous qdict_put(bs_options, "filename", ...)] Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-02iscsi: drop unused IscsiAIOCB.qiov fieldStefan Hajnoczi
The IscsiAIOCB.qiov field has been unused since commit 063c3378a9e3c25cc0afac3c72e4823d0621e352 ("block/iscsi: introduce bdrv_co_{readv, writev, flush_to_disk}") back in 2013. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20170327165005.22038-1-stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-03iscsi: fix missing unlockPaolo Bonzini
Reported by Coverity. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-27iscsi: do not use aio_context_acquire/releasePaolo Bonzini
Now that all bottom halves and callbacks take care of taking the AioContext lock, we can migrate some users away from it and to a specific QemuMutex or CoMutex. Protect libiscsi calls with a QemuMutex. Callbacks are invoked using bottom halves, so we don't even have to drop it around callback invocations. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170222180725.28611-4-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21iscsi: Add blockdev-add supportKevin Wolf
This adds blockdev-add support for iscsi devices. Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21iscsi: Add timeout optionKevin Wolf
This was previously only available with -iscsi. Again, after this patch, the -iscsi option only takes effect if an URL is given. New users are supposed to use the new driver-specific option. All -iscsi options have a corresponding driver-specific option for the iscsi block driver now. Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21iscsi: Add header-digest optionKevin Wolf
This was previously only available with -iscsi. Again, after this patch, the -iscsi option only takes effect if an URL is given. New users are supposed to use the new driver-specific option. Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21iscsi: Add initiator-name optionKevin Wolf
This was previously only available with -iscsi. Again, after this patch, the -iscsi option only takes effect if an URL is given. New users are supposed to use the new driver-specific option. Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21iscsi: Handle -iscsi user/password in bdrv_parse_filename()Kevin Wolf
This splits the logic in the old parse_chap() function into a part that parses the -iscsi options into the new driver-specific options, and another part that actually applies those options (called apply_chap() now). Note that this means that username and password specified with -iscsi only take effect when a URL is provided. This is intentional, -iscsi is a legacy interface only supported for compatibility, new users should use the proper driver-specific options. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21iscsi: Split URL into individual optionsKevin Wolf
This introduces a .bdrv_parse_filename handler for iscsi which parses an URL if given and translates it to individual options. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-21block: explicitly acquire aiocontext in aio callbacks that need itPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-16-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in bottom halves that need itPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-15-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in callbacks that need itPaolo Bonzini
This covers both file descriptor callbacks and polling callbacks, since they execute related code. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-14-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21block: explicitly acquire aiocontext in timers that need itPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170213135235.12274-13-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-27block/iscsi: avoid data corruption with cache=writebackPeter Lieven
nb_cls_shrunk in iscsi_allocmap_update can become -1 if the request starts and ends within the same cluster. This results in passing -1 to bitmap_set and bitmap_clear and they don't handle negative values properly. In the end this leads to data corruption. Fixes: e1123a3b40a1a9a625a29c8ed4debb7e206ea690 Cc: qemu-stable@nongnu.org Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1484579832-18589-1-git-send-email-pl@kamp.de> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-03aio: add AioPollFn and io_poll() interfaceStefan Hajnoczi
The new AioPollFn io_poll() argument to aio_set_fd_handler() and aio_set_event_handler() is used in the next patch. Keep this code change separate due to the number of files it touches. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-3-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-11-22block: Return -ENOTSUP rather than assert on unaligned discardsEric Blake
Right now, the block layer rounds discard requests, so that individual drivers are able to assert that discard requests will never be unaligned. But there are some ISCSI devices that track and coalesce multiple unaligned requests, turning it into an actual discard if the requests eventually cover an entire page, which implies that it is better to always pass discard requests as low down the stack as possible. In isolation, this patch has no semantic effect, since the block layer currently never passes an unaligned request through. But the block layer already has code that silently ignores drivers that return -ENOTSUP for a discard request that cannot be honored (as well as drivers that return 0 even when nothing was done). But the next patch will update the block layer to fragment discard requests, so that clients are guaranteed that they are either dealing with an unaligned head or tail, or an aligned core, making it similar to the block layer semantics of write zero fragmentation. CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-24block/iscsi: Adding new iSER transport layer optionRoy Shterman
iSER is a new transport layer supported in Libiscsi, iSER provides a zero-copy RDMA capable interface that can improve performance. In order to use the new iSER transport one need to have RDMA supported HW and to choose iser as the protocol name in Libiscsi URI. For now iSER memory buffers are pre-allocated and pre-registered, hence in order to work with iSER from QEMU, one need to enable MEMLOCK attribute in the VM to be large enough for all iSER buffers and RDMA resources. Signed-off-by: Roy Shterman <roysh@mellanox.com> Message-Id: <1476000896-18632-3-git-send-email-roysh@mellanox.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24block/iscsi: Introducing new zero-copy APIRoy Shterman
A new API to deploy zero-copy command submission. The new API takes I/O vectors list and number of I/O vectors to submit as input parameters when initiating the command. New API must be used if working with iSER transport option. Signed-off-by: Roy Shterman <roysh@mellanox.com> Message-Id: <1476000896-18632-2-git-send-email-roysh@mellanox.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-07block: use aio_bh_schedule_oneshotPaolo Bonzini
This simplifies bottom half handlers by removing calls to qemu_bh_delete and thus removing the need to stash the bottom half pointer in the opaque datum. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23Merge remote-tracking branch 'remotes/famz/tags/various-pull-request' into ↵Peter Maydell
staging # gpg: Signature made Fri 23 Sep 2016 05:58:28 BST # gpg: using RSA key 0xCA35624C6A9171C6 # gpg: Good signature from "Fam Zheng <famz@redhat.com>" # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 5003 7CB7 9706 0F76 F021 AD56 CA35 624C 6A91 71C6 * remotes/famz/tags/various-pull-request: (23 commits) docker: exec $CMD docker: Terminate instances at SIGTERM and SIGHUP docker: Support showing environment information docker: Print used options before doing configure docker: Flatten default target list in test-quick docker: Update fedora image to latest docker: Generate /packages.txt in ubuntu image docker: Generate /packages.txt in fedora image docker: Generate /packages.txt in centos6 image tests: Ignore test-uuid Add UUID files to MAINTAINERS tests: Add uuid tests uuid: Tighten uuid parse vl: Switch qemu_uuid to QemuUUID configure: Remove detection code for UUID tests: No longer dependent on CONFIG_UUID crypto: Switch to QEMU UUID API vpc: Use QEMU UUID API vdi: Use QEMU UUID API vhdx: Use QEMU UUID API ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> # Conflicts: # tests/Makefile.include
2016-09-23Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into stagingPeter Maydell
* More KVM LAPIC fixes * fix divide-by-zero regression on libiscsi SG devices * fix qemu-char segfault * add scripts/show-fixed-bugs.sh # gpg: Signature made Thu 22 Sep 2016 19:20:57 BST # gpg: using RSA key 0xBFFBD25F78C7AE83 # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * remotes/bonzini/tags/for-upstream: kvm: fix events.flags (KVM_VCPUEVENT_VALID_SMM) overwritten by 0 scripts: Add a script to check for bug URLs in the git log msmouse: Fix segfault caused by free the chr before chardev cleanup. iscsi: Fix divide-by-zero regression on raw SG devices kvm: apic: set APIC base as part of kvm_apic_put target-i386: introduce kvm_put_one_msr Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-09-23util: Add UUID APIFam Zheng
A number of different places across the code base use CONFIG_UUID. Some of them are soft dependency, some are not built if libuuid is not available, some come with dummy fallback, some throws runtime error. It is hard to maintain, and hard to reason for users. Since UUID is a simple standard with only a small number of operations, it is cleaner to have a central support in libqemuutil. This patch adds qemu_uuid_* functions that all uuid users in the code base can rely on. Except for qemu_uuid_generate which is new code, all other functions are just copy from existing fallbacks from other files. Note that qemu_uuid_parse is moved without updating the function signature to use QemuUUID, to keep this patch simple. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-Id: <1474432046-325-2-git-send-email-famz@redhat.com>
2016-09-22iscsi: Fix divide-by-zero regression on raw SG devicesEric Blake
When qemu uses iscsi devices in sg mode, iscsilun->block_size is left at 0. Prior to commits cf081fca and similar, when block limits were tracked in sectors, this did not matter: various block limits were just left at 0. But when we started scaling by block size, this caused SIGFPE. Then, in a later patch, commit a5b8dd2c added an assertion to bdrv_open_common() that request_alignment is always non-zero; which was not true for SG mode. Rather than relax that assertion, we can just provide a sane value (we don't know of any SG device with a block size smaller than qemu's default sizing of 512 bytes). One possible solution for SG mode is to just blindly skip ALL of iscsi_refresh_limits(), since we already short circuit so many other things in sg mode. But this patch takes a slightly more conservative approach, and merely guarantees that scaling will succeed, while still using multiples of the original size where possible. Resulting limits may still be zero in SG mode (that is, we mostly only fix block_size used as a denominator or which affect assertions, not all uses). Reported-by: Holger Schranz <holger@fam-schranz.de> Signed-off-by: Eric Blake <eblake@redhat.com> CC: qemu-stable@nongnu.org Message-Id: <1473283640-15756-1-git-send-email-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-20blockdev: prepare iSCSI block driver for dynamic loadingColin Lord
This commit moves the initialization of the QemuOptsList qemu_iscsi_opts struct out of block/iscsi.c in order to allow the iscsi module to be dynamically loaded. Signed-off-by: Colin Lord <clord@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1471008424-16465-2-git-send-email-clord@redhat.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-20iscsi: Switch .bdrv_co_discard() to byte-basedEric Blake
Another step towards killing off sector-based block APIs. Unlike write_zeroes, where we can be handed unaligned requests and must fail gracefully with -ENOTSUP for a fallback, we are guaranteed that discard requests are always aligned because the block layer already ignored unaligned head/tail. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 1468624988-423-13-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-20iscsi: Rely on block layer to break up large requestsEric Blake
Now that the block layer honors max_request, we don't need to bother with an EINVAL on overlarge requests, but can instead assert that requests are well-behaved. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1468607524-19021-7-git-send-email-eblake@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-19block/iscsi: allow caching of the allocation mapPeter Lieven
until now the allocation map was used only as a hint if a cluster is allocated or not. If a block was not allocated (or Qemu had no info about the allocation status) a get_block_status call was issued to check the allocation status and possibly avoid a subsequent read of unallocated sectors. If a block known to be allocated the get_block_status call was omitted. In the other case a get_block_status call was issued before every read to avoid the necessity for a consistent allocation map. To avoid the potential overhead of calling get_block_status for each and every read request this took only place for the bigger requests. This patch enhances this mechanism to cache the allocation status and avoid calling get_block_status for blocks where the allocation status has been queried before. This allows for bypassing the read request even for smaller requests and additionally omits calling get_block_status for known to be unallocated blocks. Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1468831940-15556-3-git-send-email-pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-07-19block/iscsi: fix rounding in iscsi_allocationmap_setPeter Lieven
when setting clusters as alloacted the boundaries have to be expanded. As Paolo pointed out the calculation of the number of clusters is wrong: Suppose cluster_sectors is 2, sector_num = 1, nb_sectors = 6: In the "mark allocated" case, you want to set 0..8, i.e. cluster_num=0, nb_clusters=4. 0--.--2--.--4--.--6--.--8 <--|_________________|--> (<--> = expanded) Instead you are setting nb_clusters=3, so that 6..8 is not marked. 0--.--2--.--4--.--6--.--8 <--|______________|!!! (! = wrong) Cc: qemu-stable@nongnu.org Reported-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1468831940-15556-2-git-send-email-pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@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>
2016-07-12Use #include "..." for our own headers, <...> for othersMarkus Armbruster
Tracked down with an ugly, brittle and probably buggy Perl script. Also move includes converted to <...> up so they get included before ours where that's obviously okay. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Tested-by: Eric Blake <eblake@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net>
2016-07-05block: Use bool as appropriate for BDS membersEric Blake
Using int for values that are only used as booleans is confusing. While at it, rearrange a couple of members so that all the bools are contiguous. 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: 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: 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>
2016-07-05iscsi: Set 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. 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>
2016-07-05iscsi: Advertise realistic limits to block layerEric Blake
The function sector_limits_lun2qemu() returns a value in units of the block layer's 512-byte sector, and can be as large as 0x40000000, which is much larger than the block layer's inherent limit of BDRV_REQUEST_MAX_SECTORS. The block layer already handles '0' as a synonym to the inherent limit, and it is nicer to return this value than it is to calculate an arbitrary maximum, for two reasons: we want to ensure that the block layer continues to special-case '0' as 'no limit beyond the inherent limits'; and we want to be able to someday expand the block layer to allow 64-bit limits, where auditing for uses of BDRV_REQUEST_MAX_SECTORS will help us make sure we aren't artificially constraining iscsi to old block layer limits. 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>
2016-06-29iscsi: fix assertion in is_sector_request_lun_alignedPeter Lieven
Commit 94d047a added an assertion the the request alignment check. This introduced 2 issues: a) A off-by-one error since a request of BDRV_REQUEST_MAX_SECTORS is actually allowed. b) The bdrv_get_block_status call in the read path to check the allocation status requests up to INT_MAX sectors which triggers the assertion. Fixes: 94d047a35bf663e28f8fef137544d8ea78165add Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1466414680-18383-1-git-send-email-pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-08iscsi: Convert to bdrv_co_pwrite_zeroes()Eric Blake
Another step on our continuing quest to switch to byte-based interfaces. As this is the first byte-based iscsi interface, convert is_request_lun_aligned() into two versions, one for sectors and one for bytes. Also, change from outright -EINVAL failure on an unaligned request, to instead failing with -ENOTSUP to trigger a read-modify-write fallback, particularly since the block layer should be honoring bs->request_alignment to avoid -EINVAL on read/write requests. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08block: Track write zero limits in bytesEric Blake
Another step towards removing sector-based interfaces: convert the maximum write and minimum alignment values from sectors to bytes. Rename the variables to let the compiler check that all users are converted to the new semantics. The maximum remains an int as long as BDRV_REQUEST_MAX_SECTORS is constrained by INT_MAX (this means that we can't even support a 2G write_zeroes, but just under it) - changing operation lengths to unsigned or to 64-bits is a much bigger audit, and debatable if we even want to do it (since at the core, a 32-bit platform will still have ssize_t as its underlying limit on write()). Meanwhile, alignment is changed to 'uint32_t', since it makes no sense to have an alignment larger than the maximum write, and less painful to use an unsigned type with well-defined behavior in bit operations than to have to worry about what happens if a driver mistakenly supplies a negative alignment. Add an assert that no one was trying to use sectors to get a write zeroes larger than 2G, and therefore that a later conversion to bytes won't be impacted by keeping the limit at 32 bits. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08iscsi: Use block size as minimum zero/discard alignmentEric Blake
If hardware does not advertise a minimum zero/discard alignment, we still want to guarantee that the block layer will align requests to our blocks, rather than the arbitrary 512-byte BDRV sector size. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-29block/iscsi: avoid potential overflow of acb->task->cdbPeter Lieven
at least in the path via virtio-blk the maximum size is not restricted. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1464080368-29584-1-git-send-email-pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-23iscsi: pass SCSI status back for SG_IOVadim Rozenfeld
Signed-off-by: Vadim Rozenfeld <vrozenfe@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-12block: Honor BDRV_REQ_FUA during write_zeroesEric Blake
The block layer has a couple of cases where it can lose Force Unit Access semantics when writing a large block of zeroes, such that the request returns before the zeroes have been guaranteed to land on underlying media. SCSI does not support FUA during WRITESAME(10/16); FUA is only supported if it falls back to WRITE(10/16). But where the underlying device is new enough to not need a fallback, it means that any upper layer request with FUA semantics was silently ignoring BDRV_REQ_FUA. Conversely, NBD has situations where it can support FUA but not ZERO_WRITE; when that happens, the generic block layer fallback to bdrv_driver_pwritev() (or the older bdrv_co_writev() in qemu 2.6) was losing the FUA flag. The problem of losing flags unrelated to ZERO_WRITE has been latent in bdrv_co_do_write_zeroes() since commit aa7bfbff, but back then, it did not matter because there was no FUA flag. It became observable when commit 93f5e6d8 paved the way for flags that can impact correctness, when we should have been using bdrv_co_writev_flags() with modified flags. Compare to commit 9eeb6dd, which got flag manipulation right in bdrv_co_do_zero_pwritev(). Symptoms: I tested with qemu-io with default writethrough cache (which is supposed to use FUA semantics on every write), and targetted an NBD client connected to a server that intentionally did not advertise NBD_FLAG_SEND_FUA. When doing 'write 0 512', the NBD client sent two operations (NBD_CMD_WRITE then NBD_CMD_FLUSH) to get the fallback FUA semantics; but when doing 'write -z 0 512', the NBD client sent only NBD_CMD_WRITE. The fix is do to a cleanup bdrv_co_flush() at the end of the operation if any step in the middle relied on a BDS that does not natively support FUA for that step (note that we don't need to flush after every operation, if the operation is broken into chunks based on bounce-buffer sizing). Each BDS gains a new flag .supported_zero_flags, which parallels the use of .supported_write_flags but only when accessing a zero write operation (the flags MUST be different, because of SCSI having different semantics based on WRITE vs. WRITESAME; and also because BDRV_REQ_MAY_UNMAP only makes sense on zero writes). Also fix some documentation to describe -ENOTSUP semantics, particularly since iscsi depends on those semantics. Down the road, we may want to add a driver where its .bdrv_co_pwritev() honors all three of BDRV_REQ_FUA, BDRV_REQ_ZERO_WRITE, and BDRV_REQ_MAY_UNMAP, and advertise this via bs->supported_write_flags for blocks opened by that driver; such a driver should NOT supply .bdrv_co_write_zeroes nor .supported_zero_flags. But none of the drivers touched in this patch want to do that (the act of writing zeroes is different enough from normal writes to deserve a second callback). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Make supported_write_flags a per-bds propertyEric Blake
Pre-patch, .supported_write_flags lives at the driver level, which means we are blindly declaring that all block devices using a given driver will either equally support FUA, or that we need a fallback at the block layer. But there are drivers where FUA support is a per-block decision: the NBD block driver is dependent on the remote server advertising NBD_FLAG_SEND_FUA (and has fallback code to duplicate the flush that the block layer would do if NBD had not set .supported_write_flags); and the iscsi block driver is dependent on the mode sense bits advertised by the underlying device (and is currently silently ignoring FUA requests if the underlying device does not support FUA). The fix is to make supported flags as a per-BDS option, set during .bdrv_open(). This patch moves the variable and fixes NBD and iscsi to set it only conditionally; later patches will then further simplify the NBD driver to quit duplicating work done at the block layer, as well as tackle the fact that SCSI does not support FUA semantics on WRITESAME(10/16) but only on WRITE(10/16). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12block: Introduce bdrv_driver_pwritev()Kevin Wolf
This is a function that simply calls into the block driver for doing a write, providing the byte granularity interface we want to eventually have everywhere, and using whatever interface that driver supports. This one is a bit more interesting than the version for reads: It adds support for .bdrv_co_writev_flags() everywhere, so that drivers implementing this function can drop .bdrv_co_writev() now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
2016-03-30iscsi: Support BDRV_REQ_FUAKevin Wolf
This replaces the existing hack in the iscsi driver that sent the FUA bit in writethrough mode and ignored the following flush in order to optimise the number of roundtrips (see commit 73b5394e). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
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