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2018-06-15qemu-img: Fix assert when mapping unaligned raw fileEric Blake
Commit a290f085 exposed a latent bug in qemu-img map introduced during the conversion of block status to be byte-based. Earlier in commit 5e344dd8, the internal interface get_block_status() switched to take byte-based parameters, but still called a sector-based block layer function; as such, rounding was added in the lone caller to obey the contract. However, commit 237d78f8 changed get_block_status() to truly be byte-based, at which point rounding to sector boundaries can result in calling bdrv_block_status() with 'bytes == 0' (a coding error) when the boundary between data and a hole falls mid-sector (true for the past-EOF implicit hole present in POSIX files). Fix things by removing the rounding that is now no longer necessary. See also https://bugzilla.redhat.com/1589738 Fixes: 237d78f8 Reported-by: Dan Kenigsberg <danken@redhat.com> Reported-by: Nir Soffer <nsoffer@redhat.com> Reported-by: Maor Lipchuk <mlipchuk@redhat.com> CC: qemu-stable@nongnu.org Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-11qemu-img: Remove deprecated -s snapshot_id_or_name optionThomas Huth
It has been marked as deprecated since QEMU v2.0 already, so it is time now to finally remove it. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-id: 1528288551-31641-1-git-send-email-thuth@redhat.com Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-img: Special post-backing convert handlingMax Reitz
Currently, qemu-img convert writes zeroes when it reads zeroes. Sometimes it does not because the target is initialized to zeroes anyway, so we do not need to overwrite (and thus potentially allocate) it. This is never the case for targets with backing files, though. But even they may have an area that is initialized to zeroes, and that is the area past the end of the backing file (if that is shorter than the overlay). So if the target format's unallocated blocks are zero and there is a gap between the target's backing file's end and the target's end, we do not have to explicitly write zeroes there. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1527898 Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180501165750.19242-2-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-img: Resolve relative backing paths in rebaseMax Reitz
Currently, rebase interprets a relative path for the new backing image as follows: (1) Open the new backing image with the given relative path (thus relative to qemu-img's working directory). (2) Write it directly into the overlay's backing path field (thus relative to the overlay). If the overlay is not in qemu-img's working directory, both will be different interpretations, which may either lead to an error somewhere (either rebase fails because it cannot open the new backing image, or your overlay becomes unusable because its backing path does not point to a file), or, even worse, it may result in your rebase being performed for a different backing file than what your overlay will point to after the rebase. Fix this by interpreting the target backing path as relative to the overlay, like qemu-img does everywhere else. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1569835 Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180509182002.8044-2-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-img: Recognize no creation support in -o helpMax Reitz
The only users of print_block_option_help() are qemu-img create and qemu-img convert for the output image, so this function is always used for image creation (it used to be used for amendment also, but that is no longer the case). So if image creation is not supported by either the format or the protocol, there is no need to print any option description, because the user cannot create an image like this anyway. This also fixes an assertion failure: $ qemu-img create -f bochs -o help Supported options: qemu-img: util/qemu-option.c:219: qemu_opts_print_help: Assertion `list' failed. [1] 24831 abort (core dumped) qemu-img create -f bochs -o help Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20180509210023.20283-6-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-img: Add print_amend_option_help()Max Reitz
The more generic print_block_option_help() function is not really suitable for qemu-img amend, for a couple of reasons: (1) We do not need to append the protocol-level options, as amendment happens only on one node and does not descend downwards to its children. (2) print_block_option_help() says those options are "supported". For option amendment, we do not really know that. So this new function explicitly says that those options are the creation options, and not all of them may be supported. (3) If the driver does not support option amendment, we should not print anything (except for an error message that amendment is not supported). Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1537956 Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20180509210023.20283-5-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-option: Pull out "Supported options" printMax Reitz
It really is up to the caller to decide what this list of options means. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20180509210023.20283-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11block: Add Error parameter to bdrv_amend_optionsMax Reitz
Looking at the qcow2 code that is riddled with error_report() calls, this is really how it should have been from the start. Along the way, turn the target_version/current_version comparisons at the beginning of qcow2_downgrade() into assertions (the caller has to make sure these conditions are met), and rephrase the error message on using compat=1.1 to get refcount widths other than 16 bits. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180509210023.20283-3-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11qemu-img: Amendment support implies create_optsMax Reitz
Instead of checking whether a driver has a non-NULL create_opts we should check whether it supports image amendment in the first place. If it does, it must have create_opts. On the other hand, if it does not have create_opts (so it does not support amendment either), the error message "does not support any options" is a bit useless. Stating clearly that the driver has no amendment support whatsoever is probably better. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 20180509210023.20283-2-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-01qemu-img: Convert with copy offloadingFam Zheng
The new blk_co_copy_range interface offers a more efficient way in the case of network based storage. Make use of it to allow faster convert operation. Since copy offloading cannot do zero detection ('-S') and compression (-c), only try it when these options are not used. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20180601092648.24614-11-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-05-23job: Move progress fields to JobKevin Wolf
BlockJob has fields .offset and .len, which are actually misnomers today because they are no longer tied to block device sizes, but just progress counters. As such they make a lot of sense in generic Jobs. This patch moves the fields to Job and renames them to .progress_current and .progress_total to describe their function better. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23job: Add job_is_ready()Kevin Wolf
Instead of having a 'bool ready' in BlockJob, add a function that derives its value from the job status. At the same time, this fixes the behaviour to match what the QAPI documentation promises for query-block-job: 'true if the job may be completed'. When the ready flag was introduced in commit ef6dbf1e46e, the flag never had to be reset to match the description because after being ready, the jobs would immediately complete and disappear. Job transactions and manual job finalisation were introduced only later. With these changes, jobs may stay around even after having completed (and they are not ready to be completed a second time), however their patches forgot to reset the ready flag. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23job: Move completion and cancellation to JobKevin Wolf
This moves the top-level job completion and cancellation functions from BlockJob to Job. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23job: Move single job finalisation to JobKevin Wolf
This moves the finalisation of a single job from BlockJob to Job. Some part of this code depends on job transactions, and job transactions call this code, we introduce some temporary calls from Job functions to BlockJob ones. This will be fixed once transactions move to Job, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23job: Move BlockJobCreateFlags to JobKevin Wolf
This renames the BlockJobCreateFlags constants, moves a few JOB_INTERNAL checks to job_create() and the auto_{finalize,dismiss} fields from BlockJob to Job. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23job: Replace BlockJob.completed with job_is_completed()Kevin Wolf
Since we introduced an explicit status to block job, BlockJob.completed is redundant because it can be derived from the status. Remove the field from BlockJob and add a function to derive it from the status at the Job level. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23job: Add reference countingKevin Wolf
This moves reference counting from BlockJob to Job. In order to keep calling the BlockJob cleanup code when the job is deleted via job_unref(), introduce a new JobDriver.free callback. Every block job must use block_job_free() for this callback, this is asserted in block_job_create(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-20qemu-img: remove references to GEN_DOCSJohn Snow
Nothing seemingly uses this. (jcody: commit 77bd1119ba even mentions that it appears unused) Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2018-05-15qemu-img: Use only string options in img_open_optsMax Reitz
img_open_opts() takes a QemuOpts and converts them to a QDict, so all values therein are strings. Then it may try to call qdict_get_bool(), however, which will fail with a segmentation fault every time: $ ./qemu-img info -U --image-opts \ driver=file,filename=/dev/null,force-share=off [1] 27869 segmentation fault (core dumped) ./qemu-img info -U --image-opts driver=file,filename=/dev/null,force-share=off Fix this by using qdict_get_str() and comparing the value as a string. Also, when adding a force-share value to the QDict, add it as a string so it fits the rest of the dict. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180502202051.15493-3-mreitz@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15qemu-img: Check post-truncation sizeMax Reitz
Some block drivers (iscsi and file-posix when dealing with device files) do not actually support truncation, even though they provide a .bdrv_truncate() method and will happily return success when providing a new size that does not exceed the current size. This is because these drivers expect the user to resize the image outside of qemu and then provide qemu with that information through the block_resize command (compare cb1b83e740384b4e0d950f3d7c81c02b8ce86c2e). Of course, anyone using qemu-img resize will find that behavior useless. So we should check the actual size of the image after the supposedly successful truncation took place, emit an error if nothing changed and emit a warning if the target size was not met. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1523065 Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180421163957.29872-1-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-04qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREFMarc-André Lureau
Now that we can safely call QOBJECT() on QObject * as well as its subtypes, we can have macros qobject_ref() / qobject_unref() that work everywhere instead of having to use QINCREF() / QDECREF() for QObject and qobject_incref() / qobject_decref() for its subtypes. The replacement is mechanical, except I broke a long line, and added a cast in monitor_qmp_cleanup_req_queue_locked(). Unlike qobject_decref(), qobject_unref() doesn't accept void *. Note that the new macros evaluate their argument exactly once, thus no need to shout them. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20180419150145.24795-4-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> [Rebased, semantic conflict resolved, commit message improved] Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-03-12Polish the version strings containing the package versionThomas Huth
Since commit 67a1de0d195a there is no space anymore between the version number and the parentheses when running configure with --with-pkgversion=foo : $ qemu-system-s390x --version QEMU emulator version 2.11.50(foo) But the space is included when building without that option when building from a git checkout: $ qemu-system-s390x --version QEMU emulator version 2.11.50 (v2.11.0-1494-gbec9c64-dirty) The same confusion exists with the "query-version" QMP command. Let's fix this by introducing a proper QEMU_FULL_VERSION definition that includes the space and parentheses, while the QEMU_PKGVERSION should just cleanly contain the package version string itself. Note that this also changes the behavior of the "query-version" QMP command (the space and parentheses are not included there anymore), but that's supposed to be OK since the strings there are not meant to be parsed by other tools. Fixes: 67a1de0d195a6185c39b436159c9ffc7720bf979 Buglink: https://bugs.launchpad.net/qemu/+bug/1673373 Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <1518692807-25859-1-git-send-email-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-06Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell
Block layer patches # gpg: Signature made Mon 05 Mar 2018 17:45:51 GMT # gpg: using RSA key 7F09B272C88F2FD6 # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: (38 commits) block: Fix NULL dereference on empty drive error qcow2: Replace align_offset() with ROUND_UP() block/ssh: Add basic .bdrv_truncate() block/ssh: Make ssh_grow_file() blocking block/ssh: Pull ssh_grow_file() from ssh_create() qemu-img: Make resize error message more general qcow2: make qcow2_co_create2() a coroutine_fn block: rename .bdrv_create() to .bdrv_co_create_opts() Revert "IDE: Do not flush empty CDROM drives" block: test blk_aio_flush() with blk->root == NULL block: add BlockBackend->in_flight counter block: extract AIO_WAIT_WHILE() from BlockDriverState aio: rename aio_context_in_iothread() to in_aio_context_home_thread() docs: document how to use the l2-cache-entry-size parameter specs/qcow2: Fix documentation of the compressed cluster descriptor iotest 033: add misaligned write-zeroes test via truncate block: fix write with zero flag set and iovector provided block: Drop unused .bdrv_co_get_block_status() vvfat: Switch to .bdrv_co_block_status() vpc: Switch to .bdrv_co_block_status() ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org> # Conflicts: # include/block/block.h
2018-03-02Include less of the generated modular QAPI headersMarkus Armbruster
In my "build everything" tree, a change to the types in qapi-schema.json triggers a recompile of about 4800 out of 5100 objects. The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h, qapi-types.h. Each of these headers still includes all its shards. Reduce compile time by including just the shards we actually need. To illustrate the benefits: adding a type to qapi/migration.json now recompiles some 2300 instead of 4800 objects. The next commit will improve it further. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180211093607.27351-24-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> [eblake: rebase to master] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02qemu-img: Make resize error message more generalMax Reitz
The issue: $ qemu-img resize -f qcow2 foo.qcow2 qemu-img: Expecting one image file name Try 'qemu-img --help' for more information So we gave an image file name, but we omitted the length. qemu-img thinks the last argument is always the size and removes it immediately from argv (by decrementing argc), and tries to verify that it is a valid size only at a later point. So we do not actually know whether that last argument we called "size" is indeed a size or whether the user instead forgot to specify that size but did give a file name. Therefore, the error message should be more general. Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1523458 Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180205162745.23650-1-mreitz@redhat.com Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-09Include qapi/qmp/qbool.h exactly where neededMarkus Armbruster
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-15-armbru@redhat.com>
2018-02-09Include qapi/qmp/qstring.h exactly where neededMarkus Armbruster
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-14-armbru@redhat.com>
2018-02-09Include qapi/qmp/qdict.h exactly where neededMarkus Armbruster
This cleanup makes the number of objects depending on qapi/qmp/qdict.h drop from 4550 (out of 4743) to 368 in my "build everything" tree. For qapi/qmp/qobject.h, the number drops from 4552 to 390. While there, separate #include from file comment with a blank line. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-13-armbru@redhat.com>
2018-02-09Drop superfluous includes of qapi/qmp/qerror.hMarkus Armbruster
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-6-armbru@redhat.com>
2018-02-08qemu-img: Map bench bufferFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20180116060901.17413-7-famz@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-11-21block: Add errp to bdrv_snapshot_goto()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: John Snow <jsnow@redhat.com>
2017-10-26qemu-img: Change img_compare() to be byte-basedEric Blake
In the continuing quest to make more things byte-based, change the internal iteration of img_compare(). We can finally drop the TODO assertions added earlier, now that the entire algorithm is byte-based and no longer has to shift from bytes to sectors. Most of the change is mechanical ('total_sectors' becomes 'total_size', 'sector_num' becomes 'offset', 'nb_sectors' becomes 'chunk', 'progress_base' goes from sectors to bytes); some of it is also a cleanup (sectors_to_bytes() is now unused, loss of variable 'count' added earlier in commit 51b0a488). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Change img_rebase() to be byte-basedEric Blake
In the continuing quest to make more things byte-based, change the internal iteration of img_rebase(). We can finally drop the TODO assertion added earlier, now that the entire algorithm is byte-based and no longer has to shift from bytes to sectors. Most of the change is mechanical ('num_sectors' becomes 'size', 'sector' becomes 'offset', 'n' goes from sectors to bytes); some of it is also a cleanup (use of MIN() instead of open-coding, loss of variable 'count' added earlier in commit d6a644bb). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Change compare_sectors() to be byte-basedEric Blake
In the continuing quest to make more things byte-based, change compare_sectors(), renaming it to compare_buffers() in the process. Note that one caller (qemu-img compare) only cares about the first difference, while the other (qemu-img rebase) cares about how many consecutive sectors have the same equal/different status; however, this patch does not bother to micro-optimize the compare case to avoid the comparisons of sectors beyond the first mismatch. Both callers are always passing valid buffers in, so the initial check for buffer size can be turned into an assertion. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Change check_empty_sectors() to byte-basedEric Blake
Continue on the quest to make more things byte-based instead of sector-based. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Drop redundant error message in compareEric Blake
If a read error is encountered during 'qemu-img compare', we were printing the "Error while reading offset ..." message twice; this was because our helper function was awkward, printing output on some but not all paths. Fix it to consistently report errors on all paths, so that the callers do not risk a redundant message, and update the testsuite for the improved output. Further simplify the code by hoisting the conversion from an error message to an exit code into the helper function, rather than repeating that logic at all callers (yes, the helper function is now less generic, but it's a net win in lines of code). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Add find_nonzero()Eric Blake
During 'qemu-img compare', when we are checking that an allocated portion of one file is all zeros, we don't need to waste time computing how many additional sectors after the first non-zero byte are also non-zero. Create a new helper find_nonzero() to do the check for a first non-zero sector, and rebase check_empty_sectors() to use it. The new interface intentionally uses bytes in its interface, even though it still crawls the buffer a sector at a time; it is robust to a partial sector at the end of the buffer. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Speed up compare on pre-allocated larger fileEric Blake
Compare the following images with all-zero contents: $ truncate --size 1M A $ qemu-img create -f qcow2 -o preallocation=off B 1G $ qemu-img create -f qcow2 -o preallocation=metadata C 1G On my machine, the difference is noticeable for pre-patch speeds, with more than an order of magnitude in difference caused by the choice of preallocation in the qcow2 file: $ time ./qemu-img compare -f raw -F qcow2 A B Warning: Image size mismatch! Images are identical. real 0m0.014s user 0m0.007s sys 0m0.007s $ time ./qemu-img compare -f raw -F qcow2 A C Warning: Image size mismatch! Images are identical. real 0m0.341s user 0m0.144s sys 0m0.188s Why? Because bdrv_is_allocated() returns false for image B but true for image C, throwing away the fact that both images know via lseek(SEEK_HOLE) that the entire image still reads as zero. From there, qemu-img ends up calling bdrv_pread() for every byte of the tail, instead of quickly looking for the next allocation. The solution: use block_status instead of is_allocated, giving: $ time ./qemu-img compare -f raw -F qcow2 A C Warning: Image size mismatch! Images are identical. real 0m0.014s user 0m0.011s sys 0m0.003s which is on par with the speeds for no pre-allocation. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Simplify logic in img_compare()Eric Blake
As long as we are querying the status for a chunk smaller than the known image size, we are guaranteed that a successful return will have set pnum to a non-zero size (pnum is zero only for queries beyond the end of the file). Use that to slightly simplify the calculation of the current chunk size being compared. Likewise, we don't have to shrink the amount of data operated on until we know we have to read the file, and therefore have to fit in the bounds of our buffer. Also, note that 'total_sectors_over' is equivalent to 'progress_base'. With these changes in place, sectors_to_process() is now dead code, and can be removed. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26block: Convert bdrv_get_block_status_above() to bytesEric Blake
We are gradually moving away from sector-based interfaces, towards byte-based. In the common case, allocation is unlikely to ever use values that are not naturally sector-aligned, but it is possible that byte-based values will let us be more precise about allocation at the end of an unaligned file that can do byte-based access. Changing the name of the function from bdrv_get_block_status_above() to bdrv_block_status_above() ensures that the compiler enforces that all callers are updated. Likewise, since it a byte interface allows an offset mapping that might not be sector aligned, split the mapping out of the return value and into a pass-by-reference parameter. For now, the io.c layer still assert()s that all uses are sector-aligned, but that can be relaxed when a later patch implements byte-based block status in the drivers. For the most part this patch is just the addition of scaling at the callers followed by inverse scaling at bdrv_block_status(), plus updates for the new split return interface. But some code, particularly bdrv_block_status(), gets a lot simpler because it no longer has to mess with sectors. Likewise, mirror code no longer computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop an assertion about alignment because the loop no longer depends on alignment (never mind that we don't really have a driver that reports sub-sector alignments, so it's not really possible to test the effect of sub-sector mirroring). Fix a neighboring assertion to use is_power_of_2 while there. For ease of review, bdrv_get_block_status() was tackled separately. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26block: Convert bdrv_get_block_status() to bytesEric Blake
We are gradually moving away from sector-based interfaces, towards byte-based. In the common case, allocation is unlikely to ever use values that are not naturally sector-aligned, but it is possible that byte-based values will let us be more precise about allocation at the end of an unaligned file that can do byte-based access. Changing the name of the function from bdrv_get_block_status() to bdrv_block_status() ensures that the compiler enforces that all callers are updated. For now, the io.c layer still assert()s that all callers are sector-aligned, but that can be relaxed when a later patch implements byte-based block status in the drivers. There was an inherent limitation in returning the offset via the return value: we only have room for BDRV_BLOCK_OFFSET_MASK bits, which means an offset can only be mapped for sector-aligned queries (or, if we declare that non-aligned input is at the same relative position modulo 512 of the answer), so the new interface also changes things to return the offset via output through a parameter by reference rather than mashed into the return value. We'll have some glue code that munges between the two styles until we finish converting all uses. For the most part this patch is just the addition of scaling at the callers followed by inverse scaling at bdrv_block_status(), coupled with the tweak in calling convention. But some code, particularly bdrv_is_allocated(), gets a lot simpler because it no longer has to mess with sectors. For ease of review, bdrv_get_block_status_above() will be tackled separately. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26qemu-img: Switch get_block_status() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Continue by converting an internal function (no semantic change), and simplifying its caller accordingly. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26block: Allow NULL file for bdrv_get_block_status()Eric Blake
Not all callers care about which BDS owns the mapping for a given range of the file. This patch merely simplifies the callers by consolidating the logic in the common call point, while guaranteeing a non-NULL file to all the driver callbacks, for no semantic change. The only caller that does not care about pnum is bdrv_is_allocated, as invoked by vvfat; we can likewise add assertions that the rest of the stack does not have to worry about a NULL pnum. Furthermore, this will also set the stage for a future cleanup: when a caller does not care about which BDS owns an offset, it would be nice to allow the driver to optimize things to not have to return BDRV_BLOCK_OFFSET_VALID in the first place. In the case of fragmented allocation (for example, it's fairly easy to create a qcow2 image where consecutive guest addresses are not at consecutive host addresses), the current contract requires bdrv_get_block_status() to clamp *pnum to the limit where host addresses are no longer consecutive, but allowing a NULL file means that *pnum could be set to the full length of known-allocated data. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-26qemu-img: add --shrink flag for resizePavel Butsykin
The flag is additional precaution against data loss. Perhaps in the future the operation shrink without this flag will be blocked for all formats, but for now we need to maintain compatibility with raw. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20170918124230.8152-2-pbutsykin@virtuozzo.com [mreitz: Added a missing space to a warning] Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-09-04qapi: Change data type of the FOO_lookup generated for enum FOOMarc-André Lureau
Currently, a FOO_lookup is an array of strings terminated by a NULL sentinel. A future patch will generate enums with "holes". NULL-termination will cease to work then. To prepare for that, store the length in the FOO_lookup by wrapping it in a struct and adding a member for the length. The sentinel will be dropped next. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com> [Basically redone] Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com> [Rebased]
2017-09-04qapi: Generate FOO_str() macro for QAPI enum FOOMarkus Armbruster
The next commit will put it to use. May look pointless now, but we're going to change the FOO_lookup's type, and then it'll help. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-09-04qapi: Drop superfluous qapi_enum_parse() parameter maxMarkus Armbruster
The lookup tables have a sentinel, no need to make callers pass their size. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> [Rebased, commit message corrected]
2017-08-08maint: Include bug-reporting info in --help outputEric Blake
These days, many programs are including a bug-reporting address, or better yet, a link to the project web site, at the tail of their --help output. However, we were not very consistent at doing so: only qemu-nbd and qemu-qa mentioned anything, with the latter pointing to an individual person instead of the project. Add a new #define that sets up a uniform string, mentioning both bug reporting instructions and overall project details, and which a downstream vendor could tweak if they want bugs to go to a downstream database. Then use it in all of our binaries which have --help output. The canned text intentionally references http:// instead of https:// because our https website currently causes certificate errors in some browsers. That can be tweaked later once we have resolved the web site issued. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20170803163353.19558-5-eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-24maint: Reorder include directives for qemu-{nbd, io}Eric Blake
HACKING recommends listing system includes right after osdep.h, and before any other in-project headers. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170721135047.25005-3-eblake@redhat.com>
2017-07-18qemu-img: Check for backing image if specified during createJohn Snow
Or, rather, force the open of a backing image if one was specified for creation. Using a similar -unsafe option as rebase, allow qemu-img to ignore the backing file validation if possible. It may not always be possible, as in the existing case when a filesize for the new image was not specified. This is accomplished by shifting around the conditionals in bdrv_img_create, such that a backing file is always opened unless we provide BDRV_O_NO_BACKING. qemu-img is adjusted to pass this new flag when -u is provided to create. Sorry for the heinous looking diffstat, but it's mostly whitespace. Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1213786 Signed-off-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>