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2015-11-11qcow2: Fix qcow2_get_cluster_offset() for zero clustersKevin Wolf
When searching for contiguous zero clusters, we only need to check the cluster type. Before this patch, an increasing offset (L2E_OFFSET_MASK) was expected, so that the function never returned more than a single zero cluster in practice. This patch fixes it to actually return as many contiguous zero clusters as it can. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1446657384-5907-1-git-send-email-kwolf@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-10-16block: Convert bs->backing_hd to BdrvChildKevin Wolf
This is the final step in converting all of the BlockDriverState pointers that block drivers use to BdrvChild. After this patch, bs->children contains the full list of child nodes that are referenced by a given BDS, and these children are only referenced through BdrvChild, so that updating the pointer in there is enough for changing edges in the graph. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16block: Convert bs->file to BdrvChildKevin Wolf
This patch removes the temporary duplication between bs->file and bs->file_child by converting everything to BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-09-14qcow2: Make size_to_clusters() return uint64_tMax Reitz
Sadly, some images may have more clusters than what can be represented using a plain int. We should be prepared for that case (in qcow2_check_refcounts() we actually were trying to catch that case, but since size_to_clusters() truncated the returned value, that check never did anything useful). Cc: qemu-stable <qemu-stable@nongnu.org> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-09-14qcow2: Rename BDRVQcowState to BDRVQcow2StateKevin Wolf
BDRVQcowState is already used by qcow1, and gdb is always confused which one to use. Rename the qcow2 one so they can be distinguished. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com>
2015-09-11maint: remove / fix many doubled wordsDaniel P. Berrange
Many source files have doubled words (eg "the the", "to to", and so on). Most of these can simply be removed, but a couple were actual mis-spellings (eg "to to" instead of "to do"). There was even one triple word score "to to to" :-) Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-07-08block: convert qcow/qcow2 to use generic cipher APIDaniel P. Berrange
Switch the qcow/qcow2 block driver over to use the generic cipher API, this allows it to use the pluggable AES implementations, instead of being hardcoded to use QEMU's built-in impl. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1435770638-25715-10-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-22qcow2/qcow: protect against uninitialized encryption keyDaniel P. Berrange
When a qcow[2] file is opened, if the header reports an encryption method, this is used to set the 'crypt_method_header' field on the BDRVQcow[2]State struct, and the 'encrypted' flag in the BDRVState struct. When doing I/O operations, the 'crypt_method' field on the BDRVQcow[2]State struct is checked to determine if encryption needs to be applied. The crypt_method_header value is copied into crypt_method when the bdrv_set_key() method is called. The QEMU code which opens a block device is expected to always do a check if (bdrv_is_encrypted(bs)) { bdrv_set_key(bs, ....key...); } If code forgets to do this, then 'crypt_method' is never set and so when I/O is performed, QEMU writes plain text data into a sector which is expected to contain cipher text, or when reading, will return cipher text instead of plain text. Change the qcow[2] code to consult bs->encrypted when deciding whether encryption is required, and assert(s->crypt_method) to protect against cases where the caller forgets to set the encryption key. Also put an assert in the set_key methods to protect against the case where the caller sets an encryption key on a block device that does not have encryption Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-05-22qcow2: make qcow2_cache_put() a void functionAlberto Garcia
This function never receives an invalid table pointer, so we can make it void and remove all the error checking code. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-05-22qcow2: use one single memory block for the L2/refcount cache tablesAlberto Garcia
The qcow2 L2/refcount cache contains one separate table for each cache entry. Doing one allocation per table adds unnecessary overhead and it also requires us to store the address of each table separately. Since the size of the cache is constant during its lifetime, it's better to have an array that contains all the tables using one single allocation. In my tests measuring freshly created caches with sizes 128MB (L2) and 32MB (refcount) this uses around 10MB of RAM less. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10qcow2: Use 64 bits for refcount valuesMax Reitz
Refcounts may have a width of up to 64 bits, so qemu should use the same width to represent refcount values internally. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10qcow2: Use unsigned addend for update_refcount()Max Reitz
update_refcount() and qcow2_update_cluster_refcount() currently take a signed addend. At least one caller passes a value directly derived from an absolute refcount that should be reached ("l2_refcount - 1" in expand_zero_clusters_in_l1()). Therefore, the addend should be unsigned as well; this will be especially important for 64 bit refcounts. Because update_refcount() then no longer knows whether the refcount should be increased or decreased, it now requires an additional flag which specified exactly that. The same applies to qcow2_update_cluster_refcount(). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-10qcow2: Only return status from qcow2_get_refcountMax Reitz
Refcounts can theoretically be of type uint64_t; in order to be able to represent the full range, qcow2_get_refcount() cannot use a single variable to represent both all refcount values and also keep some values reserved for errors. One solution would be to add an Error pointer parameter to qcow2_get_refcount(); however, no caller could (currently) pass that error message, so it would have to be emitted immediately and be passed to the next caller by returning -EIO or something similar. Therefore, an Error parameter does not offer any advantages here. The solution applied by this patch is simpler to use. Because no caller would be able to pass the error message, they would have to print it and free it, whereas with this patch the caller only needs to pass the returned integer (which is often a no-op from the code perspective, because that integer will be stored in a variable "ret" which will be returned by the fail path of many callers). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23qcow2: Add two more unalignment checksMax Reitz
This adds checks for unaligned L2 table offsets and unaligned data cluster offsets (actually the preallocated offsets for zero clusters) to the zero cluster expansion function. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10qcow2: Prevent numerical overflowMax Reitz
In qcow2_alloc_cluster_offset(), *num is limited to INT_MAX >> BDRV_SECTOR_BITS by all callers. However, since remaining is of type uint64_t, we might as well cast *num to that type before performing the shift. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-11-03block/qcow2: Simplify shared L2 handling in amendMax Reitz
Currently, we have a bitmap for keeping track of which clusters have been created during the zero cluster expansion process. This was necessary because we need to properly increase the refcount for shared L2 tables. However, now we can simply take the L2 refcount and use it for the cluster allocated for expansion. This will be the correct refcount and therefore we don't have to remember that cluster having been allocated any more. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Message-id: 1414404776-4919-7-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03block/qcow2: Implement status CB for amendMax Reitz
The only really time-consuming operation potentially performed by qcow2_amend_options() is zero cluster expansion when downgrading qcow2 images from compat=1.1 to compat=0.10, so report status of that operation and that operation only through the status CB. For this, approximate the progress as the number of L1 entries visited during the operation. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Message-id: 1414404776-4919-5-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-03qcow2: Allow "full" discardMax Reitz
Normally, discarded sectors should read back as zero. However, there are cases in which a sector (or rather cluster) should be discarded as if they were never written in the first place, that is, reading them should fall through to the backing file again. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1414159063-25977-2-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-23qcow2: Do not overflow when writing an L1 sectorMax Reitz
While writing an L1 table sector, qcow2_write_l1_entry() copies the respective range from s->l1_table to the local "buf" array. The size of s->l1_table does not have to be a multiple of L1_ENTRIES_PER_SECTOR; thus, limit the index which is used for copying all entries to the L1 size. Cc: qemu-stable@nongnu.org Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Peter Lieven <pl@kamp.de> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-22qcow2: Check L1/L2/reftable entries for alignmentMax Reitz
Offsets taken from the L1, L2 and refcount tables are generally assumed to be correctly aligned. However, this cannot be guaranteed if the image has been written to by something different than qemu, thus check all offsets taken from these tables for correct cluster alignment. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1409926039-29044-5-git-send-email-mreitz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-20block: Use g_new() & friends where that makes obvious senseMarkus Armbruster
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer, for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. Patch created with Coccinelle, with two manual changes on top: * Add const to bdrv_iterate_format() to keep the types straight * Convert the allocation in bdrv_drop_intermediate(), which Coccinelle inexplicably misses Coccinelle semantic patch: @@ type T; @@ -g_malloc(sizeof(T)) +g_new(T, 1) @@ type T; @@ -g_try_malloc(sizeof(T)) +g_try_new(T, 1) @@ type T; @@ -g_malloc0(sizeof(T)) +g_new0(T, 1) @@ type T; @@ -g_try_malloc0(sizeof(T)) +g_try_new0(T, 1) @@ type T; expression n; @@ -g_malloc(sizeof(T) * (n)) +g_new(T, n) @@ type T; expression n; @@ -g_try_malloc(sizeof(T) * (n)) +g_try_new(T, n) @@ type T; expression n; @@ -g_malloc0(sizeof(T) * (n)) +g_new0(T, n) @@ type T; expression n; @@ -g_try_malloc0(sizeof(T) * (n)) +g_try_new0(T, n) @@ type T; expression p, n; @@ -g_realloc(p, sizeof(T) * (n)) +g_renew(T, p, n) @@ type T; expression p, n; @@ -g_try_realloc(p, sizeof(T) * (n)) +g_try_renew(T, p, n) Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15qcow2: Catch !*host_offset for data allocationMax Reitz
qcow2_alloc_cluster_offset() uses host_offset == 0 as "no preferred offset" for the (data) cluster range to be allocated. However, this offset is actually valid and may be allocated on images with a corrupted refcount table or first refcount block. In this case, the corruption prevention should normally catch that write anyway (because it would overwrite the image header). But since 0 is a special value here, the function assumes that nothing has been allocated at all which it asserts against. Because this condition is not qemu's fault but rather that of a broken image, it shouldn't throw an assertion but rather mark the image corrupt and show an appropriate message, which this patch does by calling the corruption check earlier than it would be called normally (before the assertion). Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15qcow2: Handle failure for potentially large allocationsKevin Wolf
Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses the allocations in the qcow2 block driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-05-28qcow2: Fix memory leak in COW error pathKevin Wolf
This triggers if bs->drv becomes NULL in a concurrent request. This is currently only the case when corruption prevention kicks in (i.e. at most once per image, and after that it produces I/O errors). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-30qcow2: Check min_size in qcow2_grow_l1_table()Max Reitz
First, new_l1_size is an int64_t, whereas min_size is a uint64_t. Therefore, during the loop which adjusts new_l1_size until it equals or exceeds min_size, new_l1_size might overflow and become negative. The comparison in the loop condition however will take it as an unsigned value (because min_size is unsigned) and therefore recognize it as exceeding min_size. Therefore, the loop is left with a negative new_l1_size, which is not correct. This could be fixed by making new_l1_size uint64_t. On the other hand, however, by doing this, the while loop may take forever. If min_size is e.g. UINT64_MAX, it will take new_l1_size probably multiple overflows to reach the exact same value (if it reaches it at all). Then, right after the loop, new_l1_size will be recognized as being too big anyway. Both problems require a ridiculously high min_size value, which is very unlikely to occur; but both problems are also simply avoided by checking whether min_size is sane before calculating new_l1_size (which should still be checked separately, though). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-29qcow2: Fix discardMax Reitz
discard_single_l2() should not implement its own version of qcow2_get_cluster_type(), but rather rely on this already existing function. By doing so, it will work for compressed clusters as well (which it did not so far). Also, rename "old_offset" to "old_l2_entry", as both are quite different (and the value is indeed of the latter kind). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-04-04qcow2: Put cache reference in error caseKevin Wolf
When qcow2_get_cluster_offset() sees a zero cluster in a version 2 image, it (rightfully) returns an error. But in doing so it shouldn't leak an L2 table cache reference. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-04-01qcow2: Fix copy_sectors() with VM stateKevin Wolf
bs->total_sectors is not the highest possible sector number that could be involved in a copy on write operation: VM state is after the end of the virtual disk. This resulted in wrong values for the number of sectors to be copied (n). The code that checks for the end of the image isn't required any more because the code hasn't been calling the block layer's bdrv_read() for a long time; instead, it directly calls qcow2_readv(), which doesn't error out on VM state sector numbers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-04-01qcow2: Fix new L1 table size check (CVE-2014-0143)Kevin Wolf
The size in bytes is assigned to an int later, so check that instead of the number of entries. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-03-13qcow2: Check bs->drv in copy_sectors()Max Reitz
Before dereferencing bs->drv for a call to its member bdrv_co_readv(), copy_sectors() should check whether that pointer is indeed valid, since it may have been set to NULL by e.g. a concurrent write triggering the corruption prevention mechanism. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-02-21qcow2: Set zero flag for discarded clustersKevin Wolf
Instead of making the backing file contents visible again after a discard request, set the zero flag if possible (i.e. on version >= 3). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-02-09qcow2: remove n_start and n_end of qcow2_alloc_cluster_offset()Hu Tao
n_start can be actually calculated from offset. The number of sectors to be allocated(n_end - n_start) can be passed in in num. By removing n_start and n_end, we can save two parameters. The side effect is there is a bug in qcow2.c:preallocate() that passes incorrect n_start to qcow2_alloc_cluster_offset() is fixed. The bug can be triggerred by a larger cluster size than the default value(65536), for example: ./qemu-img create -f qcow2 \ -o 'cluster_size=131072,preallocation=metadata' file.img 4G Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-12-06qcow2: use start_of_cluster() and offset_into_cluster() everywhereHu Tao
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-28block: add flags to bdrv_*_write_zeroesPeter Lieven
Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-11-14qcow2: fix possible corruption when reading multiple clustersPeter Lieven
if multiple sectors spanning multiple clusters are read the function count_contiguous_clusters should ensure that the cluster type should not change between the clusters. Especially the for-loop should break when we have one or more normal clusters followed by a compressed cluster. Unfortunately the wrong macro was used in the mask to compare the flags. This was discovered while debugging a data corruption issue when converting a compressed qcow2 image to raw. qemu-img reads 2MB chunks which span multiple clusters. CC: qemu-stable@nongnu.org Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-11-05bswap.h: Remove cpu_to_be64wu()Peter Maydell
Replace the legacy cpu_to_be64wu() with stq_be_p(). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <rth@twiddle.net> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-id: 1383669517-25598-9-git-send-email-peter.maydell@linaro.org Signed-off-by: Anthony Liguori <aliguori@amazon.com>
2013-10-11qcow2: Use negated overflow check maskMax Reitz
In qcow2_check_metadata_overlap and qcow2_pre_write_overlap_check, change the parameter signifying the checks to perform from its current positive form to a negative one, i.e., it will no longer explicitly specify every check to perform but rather a mask of checks not to perform. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-07qcow2: Free allocated L2 cluster on errorMax Reitz
If an error occurs in l2_allocate, the allocated (but unused) L2 cluster should be freed. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-10-02qcow2: Switch L1 table in a single sequenceMax Reitz
Switching the L1 table in memory should be an atomic operation, as far as possible. Calling qcow2_free_clusters on the old L1 table on disk is not a good idea when the old L1 table is no longer valid and the address to the new one hasn't yet been written into the corresponding BDRVQcowState field. To be more specific, this can lead to segfaults due to qcow2_check_metadata_overlap trying to access the L1 table during the free operation. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-27qcow2: Remove useless count_contiguous_clusters() parameterKevin Wolf
All callers pass start = 0, and it's doubtful if any other value would actually do what you expect. Remove the parameter. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com>
2013-09-27qcow2: COMPRESSED on count_contiguous_clustersMax Reitz
Compressed clusters can never be contiguous, therefore the corresponding flag does not need to be given explicitly to count_contiguous_clusters. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27qcow2: count_contiguous_clusters and compressionMax Reitz
The function is not intended to be used on compressed clusters and will not work correctly, if used anyway, since L2E_OFFSET_MASK is not the right mask for determining the offset of compressed clusters. Therefore, assert that the first cluster is not compressed and always include the compression flag in the mask of significant flags, i.e., stop the search as soon as a compressed cluster occurs. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27qcow2: Free only newly allocated clusters on errorMax Reitz
In expand_zero_clusters_in_l1, a new cluster is only allocated if it was not already preallocated. On error, such preallocated clusters should not be freed, but only the newly allocated ones. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27qcow2: Always use error path in l2_allocateMax Reitz
Just returning -errno in some cases prevents trace_qcow2_l2_allocate_done from being executed (and, in one case, also the unused allocated L2 table from being freed). Always going down the error path fixes this. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27qcow2: Don't put invalid L2 table into cacheMax Reitz
In l2_allocate, the fail path is executed if qcow2_cache_flush fails. However, the L2 table has not yet been fetched from the L2 table cache. The qcow2_cache_put in the fail path therefore basically gives an undefined argument as the L2 table address (in this case). Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-27qcow2: Correct bitmap size in zero expansionMax Reitz
Since the expanded_clusters bitmap is addressed using host offsets in the underlying image file, the correct size to use for allocating the bitmap is not determined by the guest disk image but by the underlying host image file. Furthermore, this size may change during the expansion due to cluster allocations on growable image files. In this case, the bitmap needs to be resized as well to reflect the growth. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25qcow2: Assert against currently impossible overflowMax Reitz
If qcow2_alloc_cluster_link_l2 is called with a QCowL2Meta describing a request crossing L2 boundaries, a buffer overflow will occur. This is impossible right now since such requests are never generated (every request is shortened to L2 boundaries before) and probably also completely unintended (considering the name "QCowL2Meta"), however, it is still worth an assertion. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12qcow2-cluster: Expand zero clustersMax Reitz
Add functionality for expanding zero clusters. This is necessary for downgrading the image version to one without zero cluster support. For non-backed images, this function may also just discard zero clusters instead of truly expanding them. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12qcow2: Pass discard type to qcow2_discard_clusters()Kevin Wolf
The function will be used internally instead of only being called for guest discard requests. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2013-08-30qcow2-refcount: Repair OFLAG_COPIED errorsMax Reitz
Since the OFLAG_COPIED checks are now executed after the refcounts have been repaired (if repairing), it is safe to assume that they are correct but the OFLAG_COPIED flag may be not. Therefore, if its value differs from what it should be (considering the according refcount), that discrepancy can be repaired by correctly setting (or clearing that flag. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>