aboutsummaryrefslogtreecommitdiff
path: root/block/qcow2.c
AgeCommit message (Collapse)Author
2011-02-10qcow2: Report error for version > 2Kevin Wolf
The qcow2 driver is now declared responsible for any QCOW image that has version 2 or greater (before this, version 3 would be detected as raw). For everything newer than version 2, an error is reported. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
2011-02-10qcow2: Fix error handling for reading compressed clustersKevin Wolf
When reading a compressed cluster failed, qcow2 falsely returned success. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com>
2011-02-10qcow2: Fix error handling for immediate backing file read failureKevin Wolf
Requests could return success even though they failed when bdrv_aio_readv returned NULL for a backing file read. Reported-by: Chunqiang Tang <ctang@us.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-10QCOW2: bug fix - read base image beyond its sizeChunqiang Tang
This patch fixes the following bug in QCOW2. For a QCOW2 image that is larger than its base image, when handling a read request straddling over the end of the base image, the QCOW2 driver attempts to read beyond the end of the base image and the request would fail. This bug was found by Fast Virtual Disk (FVD)'s fully automated testing tool. The following test triggered the bug. dd if=/dev/zero of=/var/ramdisk/truth.raw count=0 bs=1 seek=1098561536 dd if=/dev/zero of=/var/ramdisk/zero-500M.raw count=0 bs=1 seek=593099264 ./qemu-img create -f qcow2 -ocluster_size=65536,backing_fmt=blksim -b /var/ramdisk/zero-500M.raw /var/ramdisk/test.qcow2 1098561536 ./qemu-io --auto --seed=30477694 --truth=/var/ramdisk/truth.raw --format=qcow2 --test=blksim:/var/ramdisk/test.qcow2 --verify_write=true --compare_before=false --compare_after=true --round=100000 --parallel=100 --io_size=10485760 --fail_prob=0 --cancel_prob=0 --instant_qemubh=true Signed-off-by: Chunqiang Tang <ctang@us.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-02-07qcow2: Really use cache=unsafe for image creationKevin Wolf
For cache=unsafe we also need to set BDRV_O_CACHE_WB, otherwise we have some strange unsafe writethrough mode. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-01-31qcow2: Add bdrv_discard supportKevin Wolf
This adds a bdrv_discard function to qcow2 that frees the discarded clusters. It does not yet pass the discard on to the underlying file system driver, but the space can be reused by future writes to the image. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-01-24qcow2: Use QcowCacheKevin Wolf
Use the new functions of qcow2-cache.c for everything that works on refcount block and L2 tables. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17Add proper -errno error return values to qcow2_open()Jes Sorensen
In addition this adds missing braces to the function to be consistent with the coding style. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17block/qcow2.c: rename qcow_ functions to qcow2_Jes Sorensen
It doesn't really make sense for functions in qcow2.c to be named qcow_ so convert the names to match correctly. Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-11-04block: Allow bdrv_flush to return errorsKevin Wolf
This changes bdrv_flush to return 0 on success and -errno in case of failure. It's a requirement for implementing proper error handle in users of bdrv_flush. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-10-22Copy snapshots out of QCOW2 diskedison
In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage. The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img. Right now, it only supports to copy the full snapshot, delta snapshot is on the way. Changes from V1: all the comments from Kevin are addressed: Add read-only checking Fix coding style Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp Signed-off-by: Disheng Su <edison@cloud.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22qcow2: Remove old image creation functionKevin Wolf
They have been #ifdef'd out by the previous patch. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22qcow2: Simplify image creationKevin Wolf
Instead of doing lots of magic for setting up initial refcount blocks and stuff create a minimal (inconsistent) image, open it and initialize the rest with regular qcow2 functions. This is a complete rewrite of the image creation function. The old implementating is #ifdef'd out and will be removed by the next patch (removing it here would have made the diff unreadable because diff tries to find similarities when it's really a rewrite) Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-10-22qcow2: Support exact L1 table growthStefan Hajnoczi
The L1 table grow operation includes a size calculation that bumps up the new L1 table size in order to anticipate the size needs of vmstate data. This helps reduce the number of times that the L1 table has to be grown when vmstate data is appended. This size overhead is not necessary during image creation, bdrv_truncate(), or snapshot goto operations. In fact, existing qemu-iotests that exercise table growth are no longer able to trigger it because image creation preallocates an L1 table that is too large after changes to qcow_create2(). This patch keeps the size calculation but also adds exact growth for callers that do not want to inflate the L1 table size unnecessarily. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-09-21qcow2: Avoid bounce buffers for AIO write requestsKevin Wolf
qcow2 used to use bounce buffers for any AIO requests. This does not only imply unnecessary copying, but also unbounded allocations which should be avoided. This patch removes bounce buffers from the normal AIO write path. Encrypted images continue to use a bounce buffer, however with constant size. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-09-21qcow2: Avoid bounce buffers for AIO read requestsKevin Wolf
qcow2 used to use bounce buffers for any AIO requests. This does not only imply unnecessary copying, but also unbounded allocations which should be avoided. This patch removes bounce buffers from the normal AIO read path, and constrains them to a constant size for encrypted images. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-06qcow2/vdi: Change check to distinguish error casesKevin Wolf
This distinguishes between harmless leaks and real corruption. Hopefully users better understand what qemu-img check wants to tell them. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-07-02qcow2: Fix error handling during metadata preallocationKevin Wolf
People were wondering why qemu-img check failed after they tried to preallocate a large qcow2 file and ran out of disk space. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-22qcow2: Use bdrv_(p)write_sync for metadata writesKevin Wolf
Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-28qcow2: Allow qcow2_get_cluster_offset to return errorsKevin Wolf
qcow2_get_cluster_offset() looks up a given virtual disk offset and returns the offset of the corresponding cluster in the image file. Errors (e.g. L2 table can't be read) are currenctly indicated by a return value of 0, which is unfortuately the same as for any unallocated cluster. So in effect we can't check for errors. This makes the old return value a by-reference parameter and returns the usual 0/-errno error code. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-22Fix %lld or %llx printf format useBlue Swirl
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-17block: Avoid unchecked casts for AIOCBsKevin Wolf
Use container_of for one direction and &acb->common for the other one. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-07qcow2: Remove static forward declarationKevin Wolf
OpenBSDs gcc is said to generate warnings for this declaration, so don't reference bdrv_qcow2 directly, but look it up using bdrv_find_format. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-07Revert "Fix OpenBSD build"Kevin Wolf
This reverts commit 20d97356c9df6d68fbd37d6334fdb7063f24eab6. The BlockDriver definition should stay at the end of source files. Conflicts: block/qcow2.c Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-05-03qcow2: Implement bdrv_truncate() for growing imagesStefan Hajnoczi
This patch adds the ability to grow qcow2 images in-place using bdrv_truncate(). This enables qemu-img resize command support for qcow2. Snapshots are not supported and bdrv_truncate() will return -ENOTSUP. The notion of resizing an image with snapshots could lead to confusion: users may expect snapshots to remain unchanged, but this is not possible with the current qcow2 on-disk format where the header.size field is global instead of per-snapshot. Others may expect snapshots to change size along with the current image data. I think it is safest to not support snapshots and perhaps add behavior later if there is a consensus. Backing images continue to work. If the image is now larger than its backing image, zeroes are read when accessing beyond the end of the backing image. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03block: Open the underlying image file in generic codeKevin Wolf
Format drivers shouldn't need to bother with things like file names, but rather just get an open BlockDriverState for the underlying protocol. This patch introduces this behaviour for bdrv_open implementation. For protocols which need to access the filename to open their file/device/connection/... a new callback bdrv_file_open is introduced which doesn't get an underlying file opened. For now, also some of the more obscure formats use bdrv_file_open because they open() the file themselves instead of using the block.c functions. They need to be fixed in later patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23Fix OpenBSD buildBlue Swirl
GCC 3.3.5 generates warnings for static forward declarations of data, so rearrange code to use static forward declarations of functions instead. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-04-23qcow2: Use QLIST_FOREACH_SAFE macroStefan Hajnoczi
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23Replace calls of old bdrv_openKevin Wolf
What is known today as bdrv_open2 becomes the new bdrv_open. All remaining callers of the old function are converted to the new one. In some places they even know the right format, so they should have used bdrv_open2 from the beginning. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23qcow2: Fix creation of large imagesKevin Wolf
qcow_create2 assumes that the new image will only need one cluster for its refcount table initially. Obviously that's not true any more when the image is big enough (exact value depends on the cluster size). This patch calculates the refcount table size dynamically. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23qcow2: Trigger blkdebug eventsKevin Wolf
This adds blkdebug events to qcow2 to allow injecting I/O errors in specific places. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-10qcow2: Remove request from in-flight list after errorKevin Wolf
If we complete a request with a failure we need to remove it from the list of requests that are in flight. If we don't do it, the next time the same AIOCB is used for a cluster allocation it will create a loop in the list and qemu will hang in an endless loop. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-04-10qcow2: Don't ignore immediate read/write failuresKevin Wolf
Returning -EIO is far from optimal, but at least it's an error code. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-03-09qcow2: return errno instead of -1Juan Quintela
Signed-off-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-23qcow2: Fix image creation regressionKevin Wolf
When checking for errors, commit db89119d compares with the wrong values, failing image creation even when there was no error. Additionally, if an error has occured, we can't preallocate the image (it's likely broken). This unbreaks test 023 of qemu-iotests. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26qcow2: rename two QCowAIOCB membersChristoph Hellwig
The n member is not very descriptive and very hard to grep, rename it to cur_nr_sectors to better indicate what it is used for. Also rename nb_sectors to remaining_sectors as that is what it is used for. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26Ask for read-write permissions when opening filesNaphtali Sprei
Found some places that seems needs this explicitly, now that read-write is not the default. Signed-off-by: Naphtali Sprei <nsprei@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26block/qcow2.c: fix warnings with _FORTIFY_SOURCEKirill A. Shutemov
CC block/qcow2.o cc1: warnings being treated as errors block/qcow2.c: In function 'qcow_create2': block/qcow2.c:829: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:838: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:839: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:841: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:844: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:849: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:852: error: ignoring return value of 'write', declared with attribute warn_unused_result block/qcow2.c:855: error: ignoring return value of 'write', declared with attribute warn_unused_result make: *** [block/qcow2.o] Error 1 Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26qcow2: Return 0/-errno in qcow2_alloc_cluster_offsetKevin Wolf
Returning 0/-errno allows it to distingush different errors classes. The cluster offset of newly allocated clusters is now returned in the QCowL2Meta struct. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26qcow2: Fix error handling in qcow_save_vmstateKevin Wolf
Don't assume success but pass the bdrv_pwrite return value on. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13qcow/qcow2: implement bdrv_aio_flushKevin Wolf
Now that we do not have to flush the backing device anymore implementing the bdrv_aio_flush method for image formats is trivial. [hch: forward ported to qemu mainline from a product tree] Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-13block: Add bdrv_change_backing_fileKevin Wolf
Introduce the functions needed to change the backing file of an image. The function is implemented for qcow2. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-12-03qcow2: Store exact backing format lengthKevin Wolf
Currently qcow2 unnecessarily rounds up the length of the backing format string to the next multiple of 8. At the same time, the array in BlockDriverState can only hold 15 characters, so in effect backing formats with 9 characters or more don't work (e.g. host_device). Save the real string length and things start to work for all valid image format names. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09qcow2: Allow qcow2 disk images with size zeroStefan Weil
Images with disk size 0 may be used for VM snapshots, but not to save normal block data. It is possible to create such images using qemu-img, but opening them later fails. So even "qemu-img info image.qcow2" is not possible for an image created with "qemu-img create -f qcow2 image.qcow2 0". This is fixed here. Signed-off-by: Stefan Weil <weil@mail.berlios.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-27Revert "qcow2: Bring synchronous read/write back to life"Kevin Wolf
It was merely a workaround and the real fix is done now. This reverts commit ef845c3bf421290153154635dc18eaa677cecb43. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-15qcow2: Bring synchronous read/write back to lifeKevin Wolf
When the synchronous read and write functions were dropped, they were replaced by generic emulation functions. Unfortunately, these emulation functions don't provide the same semantics as the original functions did. The original bdrv_read would mean that we read some data synchronously and that we won't be interrupted during this read. The latter assumption is no longer true with the emulation function which needs to use qemu_aio_poll and therefore allows the callback of any other concurrent AIO request to be run during the read. Which in turn means that (meta)data read earlier could have changed and be invalid now. qcow2 is not prepared to work in this way and it's just scary how many places there are where other requests could run. I'm not sure yet where exactly it breaks, but you'll see breakage with virtio on qcow2 with a backing file. Providing synchronous functions again fixes the problem for me. Patchworks-ID: 35437 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-12Fix sys-queue.h conflict for goodBlue Swirl
Problem: Our file sys-queue.h is a copy of the BSD file, but there are some additions and it's not entirely compatible. Because of that, there have been conflicts with system headers on BSD systems. Some hacks have been introduced in the commits 15cc9235840a22c289edbe064a9b3c19c5f49896, f40d753718c72693c5f520f0d9899f6e50395e94, 96555a96d724016e13190b28cffa3bc929ac60dc and 3990d09adf4463eca200ad964cc55643c33feb50 but the fixes were fragile. Solution: Avoid the conflict entirely by renaming the functions and the file. Revert the previous hacks. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2009-09-09qcow2: Order concurrent AIO requests on the same unallocated clusterKevin Wolf
When two AIO requests write to the same cluster, and this cluster is unallocated, currently both requests allocate a new cluster and the second one merges the first one when it is completed. This means an cluster allocation, a read and a cluster deallocation which cause some overhead. If we simply let the second request wait until the first one is done, we improve overall performance with AIO requests (specifially, qcow2/virtio combinations). This patch maintains a list of in-flight requests that have allocated new clusters. A second request touching the same cluster is limited so that it either doesn't touch the allocation of the first request (so it can have a non-overlapping allocation) or it waits for the first request to complete. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-09qcow2: Fix metadata preallocationKevin Wolf
The wrong version of the preallocation patch has been applied, so this is the remaining diff. We can't use truncate to grow the image file to the right size because we don't know if metadata has been written after the last data cluster. In this case truncate would shrink the file and destroy its metadata. Write a zero sector at the end of the virtual disk instead to ensure that the file is big enough. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-08-29Fix gcc 3 warning about uninitialized variableBlue Swirl
If nb_sectors is 0, cluster_offset will not be initialized. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>