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2012-08-10block: add BLOCK_O_CHECK for qemu-img checkStefan Hajnoczi
Image formats with a dirty bit, like qed and qcow2, repair dirty image files upon open with BDRV_O_RDWR. Performing automatic repair when qemu-img check runs is not ideal because the bdrv_open() call repairs the image before the actual bdrv_check() call from qemu-img.c. Fix this "double repair" since it leads to confusing output from qemu-img check. Tell the block driver that this image is being opened just for bdrv_check(). This skips automatic repair and qemu-img.c can invoke it manually with bdrv_check(). Update the golden output for qemu-iotests 039 to reflect the new qemu-img check output. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-10qcow2: mark image clean after repair succeedsStefan Hajnoczi
The dirty bit is cleared after image repair succeeds in qcow2_open(). Move this into qcow2_check() so that all callers benefit from this behavior when fix mode is enabled. This is necessary so qemu-img check can call .bdrv_check() and mark the image clean. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06qcow2: implement lazy refcountsStefan Hajnoczi
Lazy refcounts is a performance optimization for qcow2 that postpones refcount metadata updates and instead marks the image dirty. In the case of crash or power failure the image will be left in a dirty state and repaired next time it is opened. Reducing metadata I/O is important for cache=writethrough and cache=directsync because these modes guarantee that data is on disk after each write (hence we cannot take advantage of caching updates in RAM). Refcount metadata is not needed for guest->file block address translation and therefore does not need to be on-disk at the time of write completion - this is the motivation behind the lazy refcount optimization. The lazy refcount optimization must be enabled at image creation time: qemu-img create -f qcow2 -o compat=1.1,lazy_refcounts=on a.qcow2 10G qemu-system-x86_64 -drive if=virtio,file=a.qcow2,cache=writethrough Update qemu-iotests 031 and 036 since the extension header size changes when we add feature bit table entries. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06qcow2: introduce dirty bitStefan Hajnoczi
This patch adds an incompatible feature bit to mark images that have not been closed cleanly. When a dirty image file is opened a consistency check and repair is performed. Update qemu-iotests 031 and 036 since the extension header size changes when we add feature bit table entries. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-07-09Merge remote-tracking branch 'mjt/mjt-iov2' into stagingAnthony Liguori
* mjt/mjt-iov2: rewrite iov_send_recv() and move it to iov.c cleanup qemu_co_sendv(), qemu_co_recvv() and friends export iov_send_recv() and use it in iov_send() and iov_recv() rename qemu_sendv to iov_send, change proto and move declarations to iov.h change qemu_iovec_to_buf() to match other to,from_buf functions consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent allow qemu_iovec_from_buffer() to specify offset from which to start copying consolidate qemu_iovec_memset{,_skip}() into single function and use existing iov_memset() rewrite iov_* functions change iov_* function prototypes to be more appropriate virtio-serial-bus: use correct lengths in control_out() message Conflicts: tests/Makefile Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-07-09qcow2: fix #ifdef'd qcow2_check_refcounts() callersStefan Hajnoczi
The DEBUG_ALLOC qcow2.h macro enables additional consistency checks throughout the code. This makes it easier to spot corruptions that are introduced during development. Since consistency check is an expensive operation the DEBUG_ALLOC macro is used to compile checks out in normal builds and qcow2_check_refcounts() calls missed the addition of a new function argument. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15qcow2: fix autoclear image header updateStefan Hajnoczi
The autoclear feature bits can be used for qcow2 file format features that are safe to "drop" by old programs that do not understand the feature. Upon opening the image file unknown autoclear feature bits are cleared and the image file header is rewritten, but this was happening too early in the code when critical header fields were not yet loaded. Process autoclear feature bits after all necessary header information has been loaded. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15qcow2: always operate caches in writeback modePaolo Bonzini
Writethrough does not need special-casing anymore in the qcow2 caches. The block layer adds flushes after every guest-initiated data write, and these will also flush the qcow2 caches to the OS. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15qcow2: Support for fixing refcount inconsistenciesKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15qemu-img check -r for repairing imagesKevin Wolf
The QED block driver already provides the functionality to not only detect inconsistencies in images, but also fix them. However, this functionality cannot be manually invoked with qemu-img, but the check happens only automatically during bdrv_open(). This adds a -r switch to qemu-img check that allows manual invocation of an image repair. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-11change qemu_iovec_to_buf() to match other to,from_buf functionsMichael Tokarev
It now allows specifying offset within qiov to start from and amount of bytes to copy. Actual implementation is just a call to iov_to_buf(). Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistentMichael Tokarev
qemu_iovec_concat() is currently a wrapper for qemu_iovec_copy(), use the former (with extra "0" arg) in a few places where it is used. Change skip argument of qemu_iovec_copy() from uint64_t to size_t, since size of qiov itself is size_t, so there's no way to skip larger sizes. Rename it to soffset, to make it clear that the offset is applied to src. Also change the only usage of uint64_t in hw/9pfs/virtio-9p.c, in v9fs_init_qiov_from_pdu() - all callers of it actually uses size_t too, not uint64_t. One added restriction: as for all other iovec-related functions, soffset must point inside src. Order of argumens is already good: qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, int c, size_t bytes) vs: qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t soffset, size_t sbytes) (note soffset is after _src_ not dst, since it applies to src; for memset it applies to qiov). Note that in many places where this function is used, the previous call is qemu_iovec_reset(), which means many callers actually want copy (replacing dst content), not concat. So we may want to add a wrapper like qemu_iovec_copy() with the same arguments but which calls qemu_iovec_reset() before _concat(). Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11allow qemu_iovec_from_buffer() to specify offset from which to start copyingMichael Tokarev
Similar to qemu_iovec_memset(QEMUIOVector *qiov, size_t offset, int c, size_t bytes); the new prototype is: qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset, const void *buf, size_t bytes); The processing starts at offset bytes within qiov. This way, we may copy a bounce buffer directly to a middle of qiov. This is exactly the same function as iov_from_buf() from iov.c, so use the existing implementation and rename it to qemu_iovec_from_buf() to be shorter and to match the utility function. As with utility implementation, we now assert that the offset is inside actual iovec. Nothing changed for current callers, because `offset' parameter is new. While at it, stop using "bounce-qiov" in block/qcow2.c and copy decrypted data directly from cluster_data instead of recreating a temp qiov for doing that. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11consolidate qemu_iovec_memset{,_skip}() into single function and use ↵Michael Tokarev
existing iov_memset() This patch combines two functions into one, and replaces the implementation with already existing iov_memset() from iov.c. The new prototype of qemu_iovec_memset(): size_t qemu_iovec_memset(qiov, size_t offset, int fillc, size_t bytes) It is different from former qemu_iovec_memset_skip(), and I want to make other functions to be consistent with it too: first how much to skip, second what, and 3rd how many of it. It also returns actual number of bytes filled in, which may be less than the requested `bytes' if qiov is smaller than offset+bytes, in the same way iov_memset() does. While at it, use utility function iov_memset() from iov.h in posix-aio-compat.c, where qiov was used. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-05-25qcow2: don't leak buffer for unexpected qcow_version in headerJim Meyering
Signed-off-by: Jim Meyering <meyering@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-14qcow2: Don't ignore failure to clear autoclear flagsKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10block: push bdrv_change_backing_file error checking up from driversPaolo Bonzini
This check applies to all drivers, but QED lacks it. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-07qcow2: lock on preallocZhi Yong Wu
preallocate() will be locked. This is required because qcow2_alloc_cluster_link_l2() assumes that it runs under a lock that it can drop while COW is being performed. Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-02block/qcow2: Add missing GCC_FMT_ATTR to function report_unsupported()Stefan Weil
Cc: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20qcow2: Zero write supportKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20qcow2: Support for feature table header extensionKevin Wolf
Instead of printing an ugly bitmask, qemu can now print a more helpful string even for yet unknown features. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20qcow2: Support reading zero clustersKevin Wolf
This adds support for reading zero clusters in version 3 images. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20qcow2: Version 3 imagesKevin Wolf
This adds the basic infrastructure to qcow2 to handle version 3 images. It includes code to create v3 images, allow header updates for v3 images and checks feature bits. It still misses support for zero clusters, so this is not a fully compliant implementation of v3 yet. The default for creating new images stays at v2 for now. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20qcow2: Ignore reserved bits in get_cluster_offsetKevin Wolf
With this change, reading from a qcow2 image ignores all reserved bits that are set in an L1 or L2 table entry. Now get_cluster_offset() assigns *cluster_offset only the offset without any other flags. The cluster type is not longer encoded in the offset, but a positive return value in case of success. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05block: push recursive flushing up from driversPaolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-03-12qcow2: Add error messages in qcow2_truncateKevin Wolf
qemu-img resize has some limitations with qcow2, but the user is only told that "this image format does not support resize". Quite confusing, so add some more detailed error_report() calls and change "this image format" into "this image". Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-03-12qcow2: Add some tracingKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29qcow2: Reject too large header extensionsKevin Wolf
Image files that make qemu-img info read several gigabytes into the unknown header extensions list are bad. Just fail opening the image if an extension claims to be larger than the header extension area. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29qcow2: Fix offset in qcow2_read_extensionsKevin Wolf
The spec says that the length of extensions is padded to 8 bytes, not the offset. Currently this is the same because the header size is a multiple of 8, so this is only about compatibility with future changes to the header size. While touching it, move the calculation to a common place instead of duplicating it for each header extension type. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-02-29qcow2: Fix build with DEBUG_EXT enabledKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09qcow2: Keep unknown header extension when rewriting headerKevin Wolf
If we want header extensions to work as compatible extensions, we can't destroy yet unknown header extensions when rewriting the header (e.g. for changing the backing file). Save all unknown header extensions in a list of blobs and include them in a new header. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-02-09qcow2: Update whole header at onceKevin Wolf
In order to switch the backing file, qcow2 issues multiple write requests that only changed a part of the image header. Any failure after the first one would leave the header in an corrupted state. With this patch, the whole header is written at once, so we can't fail in the middle. At the same time, this gives us a reusable functions that updates all fields of the qcow2 header and not only the backing file. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15block/qcow2.c: call qcow2_free_snapshots in the function of qcow2_closeLi Zhi Hui
Signed-off-by: Li Zhi Hui <zhihuili@linux.vnet.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05Merge remote-tracking branch 'kwolf/for-anthony' into stagingAnthony Liguori
2011-12-05coroutine: add qemu_co_queue_restart_all()Stefan Hajnoczi
It's common to wake up all waiting coroutines. Introduce the qemu_co_queue_restart_all() function to do this instead of looping over qemu_co_queue_next() in every caller. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05block: convert qcow2, qcow2, and vmdk to .bdrv_co_is_allocated()Stefan Hajnoczi
The qcow2, qcow, and vmdk block drivers are based on coroutines. They have a coroutine mutex which protects internal state. We can convert the .bdrv_is_allocated() function to .bdrv_co_is_allocated() by holding the mutex around the cluster lookup operation. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-05qcow2: Return real error code in qcow2_read_snapshotsKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-12-05block: Add coroutine_fn marker to coroutine functionsDong Xu Wang
Looks better when reviewing these source files. Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-02fix spelling in block sub directoryDong Xu Wang
Cc: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-11-21qcow2: implement bdrv_invalidate_cache (v2)Anthony Liguori
We don't reopen the actual file, but instead invoke the close and open routines. We specifically ignore the backing file since it's contents are read-only and therefore immutable. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-11block: Introduce bdrv_co_flush_to_osKevin Wolf
qcow2 has a writeback metadata cache, so flushing a qcow2 image actually consists of writing back that cache to the protocol and only then flushes the protocol in order to get everything stable on disk. This introduces a separate bdrv_co_flush_to_os to reflect the split. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11block: Rename bdrv_co_flush to bdrv_co_flush_to_diskKevin Wolf
There are two different types of flush that you can do: Flushing one level up to the OS (i.e. writing data to the host page cache) or flushing it all the way down to the disk. The existing functions flush to the disk, reflect this in the function name. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28block: fix qcow2_co_flush deadlockDong Xu Wang
If qcow2_cache_flush failed, s->lock will not be unlock. Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21block: change discard to co_discardPaolo Bonzini
Since coroutine operation is now mandatory, convert both bdrv_discard implementations to coroutines. For qcow2, this means taking the lock around the operation. raw-posix remains synchronous. The bdrv_discard callback is then unused and can be eliminated. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21block: change flush to co_flushPaolo Bonzini
Since coroutine operation is now mandatory, convert all bdrv_flush implementations to coroutines. For qcow2, this means taking the lock. Other implementations are simpler and just forward bdrv_flush to the underlying protocol, so they can avoid the lock. The bdrv_flush callback is then unused and can be eliminated. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21qcow2: Fix bdrv_write_compressed error handlingKevin Wolf
If during allocation of compressed clusters the cluster was already allocated uncompressed, fail and properly release the l2_table (the latter avoids a failed assertion). While at it, make it return some real error numbers instead of -1. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
2011-10-21block: drop redundant bdrv_flush implementationStefan Hajnoczi
Block drivers now only need to provide either of .bdrv_co_flush, .bdrv_aio_flush() or for legacy drivers .bdrv_flush(). Remove the redundant .bdrv_flush() implementations. [Paolo Bonzini: change raw driver to bdrv_co_flush] Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12qcow2: align cluster_data to block to improve performance using O_DIRECTFrediano Ziglio
Signed-off-by: Frediano Ziglio <freddy77@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06qcow2: Fix error cases to run depedent requestsKevin Wolf
Requests depending on a failed request would end up waiting forever. This fixes the error path to continue dependent requests even when the request has failed. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-06qcow2: Properly initialise QcowL2MetaKevin Wolf
Dependency list pointers filled with random garbage from the stack aren't a good idea. Signed-off-by: Kevin Wolf <kwolf@redhat.com>