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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: Make bdrv_round_to_clusters() signature more usefulEric Blake
In the process of converting sector-based interfaces to bytes, I'm finding it easier to represent a byte count as a 64-bit integer at the block layer (even if we are internally capped by SIZE_MAX or even INT_MAX for individual transactions, it's still nicer to not have to worry about truncation/overflow issues on as many variables). Update the signature of bdrv_round_to_clusters() to uniformly use int64_t, matching the signature already chosen for bdrv_is_allocated and the fact that off_t is also a signed type, then adjust clients according to the required fallout (even where the result could now exceed 32 bits, no client is directly assigning the result into a 32-bit value without breaking things into a loop first). Signed-off-by: Eric Blake <eblake@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>
2017-10-06block/mirror: check backing in bdrv_mirror_top_flushVladimir Sementsov-Ogievskiy
Backing may be zero after failed bdrv_append in mirror_start_job, which leads to SIGSEGV. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20170929152255.5431-1-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-06block/mirror: check backing in bdrv_mirror_top_refresh_filenameVladimir Sementsov-Ogievskiy
Backing may be zero after failed bdrv_attach_child in bdrv_set_backing_hd, which leads to SIGSEGV. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-id: 20170928120300.58164-1-vsementsov@virtuozzo.com Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-10-06mirror: Switch mirror_dirty_init() to byte-based iterationEric Blake
Now that we have adjusted the majority of the calls this function makes to be byte-based, it is easier to read the code if it makes passes over the image using bytes rather than sectors. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06dirty-bitmap: Change bdrv_[re]set_dirty_bitmap() to use bytesEric Blake
Some of the callers were already scaling bytes to sectors; others can be easily converted to pass byte offsets, all in our shift towards a consistent byte interface everywhere. Making the change will also make it easier to write the hold-out callers to use byte rather than sectors for their iterations; it also makes it easier for a future dirty-bitmap patch to offload scaling over to the internal hbitmap. Although all callers happen to pass sector-aligned values, make the internal scaling robust to any sub-sector requests. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06dirty-bitmap: Change bdrv_get_dirty_locked() to take bytesEric Blake
Half the callers were already scaling bytes to sectors; the other half can eventually be simplified to use byte iteration. Both callers were already using the result as a bool, so make that explicit. Making the change also makes it easier for a future dirty-bitmap patch to offload scaling over to the internal hbitmap. Remember, asking whether a byte is dirty is effectively asking whether the entire granularity containing the byte is dirty, since we only track dirtiness by granularity. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06dirty-bitmap: Change bdrv_get_dirty_count() to report bytesEric Blake
Thanks to recent cleanups, all callers were scaling a return value of sectors into bytes; do the scaling internally instead. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06dirty-bitmap: Change bdrv_dirty_iter_next() to report byte offsetEric Blake
Thanks to recent cleanups, most callers were scaling a return value of sectors into bytes (the exception, in qcow2-bitmap, will be converted to byte-based iteration later). Update the interface to do the scaling internally instead. In qcow2-bitmap, the code was specifically checking for an error return of -1. To avoid a regression, we either have to make sure we continue to return -1 (rather than a scaled -512) on error, or we have to fix the caller to treat all negative values as error rather than just one magic value. It's easy enough to make both changes at the same time, even though either one in isolation would work. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06dirty-bitmap: Set iterator start by offset, not sectorEric Blake
All callers to bdrv_dirty_iter_new() passed 0 for their initial starting point, drop that parameter. Most callers to bdrv_set_dirty_iter() were scaling a byte offset to a sector number; the exception qcow2-bitmap will be converted later to use byte rather than sector iteration. Move the scaling to occur internally to dirty bitmap code instead, so that callers now pass in bytes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-26block: Add reopen_queue to bdrv_child_perm()Kevin Wolf
In the context of bdrv_reopen(), we'll have to look at the state of the graph as it will be after the reopen. This interface addition is in preparation for the change. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-04block: add default implementations for bdrv_co_get_block_status()Manos Pitsidianakis
bdrv_co_get_block_status_from_file() and bdrv_co_get_block_status_from_backing() set *file to bs->file and bs->backing respectively, so that bdrv_co_get_block_status() can recurse to them. Future block drivers won't have to duplicate code to implement this. Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-23mirror: Mark target BB as "force allow inactivate"Fam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170823134242.12080-4-famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
2017-07-24block: Skip implicit nodes in query-block/blockstatsKevin Wolf
Commits 0db832f and 6cdbceb introduced the automatic insertion of filter nodes above the top layer of mirror and commit block jobs. The assumption made there was that since libvirt doesn't do node-level management of the block layer yet, it shouldn't be affected by added nodes. This is true as far as commands issued by libvirt are concerned. It only uses BlockBackend names to address nodes, so any operations it performs still operate on the root of the tree as intended. However, the assumption breaks down when you consider query commands, which return data for the wrong node now. These commands also return information on some child nodes (bs->file and/or bs->backing), which libvirt does make use of, and which refer to the wrong nodes, too. One of the consequences is that oVirt gets wrong information about the image size and stops the VM in response as long as a mirror or commit job is running: https://bugzilla.redhat.com/show_bug.cgi?id=1470634 This patch fixes the problem by hiding the implicit nodes created automatically by the mirror and commit block jobs in the output of query-block and BlockBackend-based query-blockstats as long as the user doesn't indicate that they are aware of those nodes by providing a node name for them in the QMP command to start the block job. The node-based commands query-named-block-nodes and query-blockstats with query-nodes=true still show all nodes, including implicit ones. This ensures that users that are capable of node-level management can still access the full information; users that only know BlockBackends won't use these commands. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Tested-by: Eric Blake <eblake@redhat.com>
2017-07-11block: Add PreallocMode to blk_truncate()Max Reitz
blk_truncate() itself will pass that value to bdrv_truncate(), and all callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF for now. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20170613202107.10125-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-10block: Make bdrv_is_allocated_above() byte-basedEric 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 signature of the function to use int64_t *pnum 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. Therefore, for the most part this patch is just the addition of scaling at the callers followed by inverse scaling at bdrv_is_allocated(). But some code, particularly stream_run(), gets a lot simpler because it no longer has to mess with sectors. Leave comments where we can further simplify by switching to byte-based iterations, once later patches eliminate the need for sector-aligned operations. For ease of review, bdrv_is_allocated() was tackled separately. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Switch mirror_iteration() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Change the internal loop iteration of mirroring to track by bytes instead of sectors (although we are still guaranteed that we iterate by steps that are both sector-aligned and multiples of the granularity). Drop the now-unused mirror_clip_sectors(). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Switch mirror_do_read() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Convert another internal function, preserving all existing semantics, and adding one more assertion that things are still sector-aligned (so that conversions to sectors in mirror_read_complete don't need to round). Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Switch mirror_cow_align() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Convert another internal function (no semantic change), and add mirror_clip_bytes() as a counterpart to mirror_clip_sectors(). Some of the conversion is a bit tricky, requiring temporaries to convert between units; it will be cleared up in a following patch. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Update signature of mirror_clip_sectors()Eric Blake
Rather than having a void function that modifies its input in-place as the output, change the signature to reduce a layer of indirection and return the result. Suggested-by: John Snow <jsnow@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Switch mirror_do_zero_or_discard() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Convert another internal function (no semantic change). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10mirror: Switch MirrorBlockJob 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 structure (no semantic change), and all references to the buffer size. Add an assertion that our use of s->granularity >> BDRV_SECTOR_BITS (necessary for interaction with sector-based dirty bitmaps, until a later patch converts those to be byte-based) does not suffer from truncation problems. [checkpatch has a false positive on use of MIN() in this patch] Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10trace: Show blockjob actions via bytes, not sectorsEric Blake
Upcoming patches are going to switch to byte-based interfaces instead of sector-based. Even worse, trace_backup_do_cow_enter() had a weird mix of cluster and sector indices. The trace interface is low enough that there are no stability guarantees, and therefore nothing wrong with changing our units, even in cases like trace_backup_do_cow_skip() where we are not changing the trace output. So make the tracing uniformly use bytes. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10blockjob: Track job ratelimits via bytes, not sectorsEric Blake
The user interface specifies job rate limits in bytes/second. It's pointless to have our internal representation track things in sectors/second, particularly since we want to move away from sector-based interfaces. Fix up a doc typo found while verifying that the ratelimit code handles the scaling difference. Repetition of expressions like 'n * BDRV_SECTOR_SIZE' will be cleaned up later when functions are converted to iterate over images by bytes rather than by sectors. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10block: Simplify use of BDRV_BLOCK_RAWEric Blake
The lone caller that cares about a return of BDRV_BLOCK_RAW (namely, io.c:bdrv_co_get_block_status) completely replaces the return value, so there is no point in passing BDRV_BLOCK_DATA. 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>
2017-06-26block: change variable names in BlockDriverStateManos Pitsidianakis
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related functions (and some others) to 'int bytes', as they both refer to bytes. This helps with code legibility. Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr> Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-16block: protect modification of dirty bitmaps with a mutexPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-17-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16block: introduce dirty_bitmap_mutexPaolo Bonzini
It protects only the list of dirty bitmaps; in the next patch we will also protect their content. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-15-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-05-30Merge remote-tracking branch 'kwolf/tags/for-upstream' into stagingStefan Hajnoczi
Block layer patches # gpg: Signature made Mon 29 May 2017 03:34:59 PM BST # gpg: using RSA key 0x7F09B272C88F2FD6 # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * kwolf/tags/for-upstream: block/file-*: *_parse_filename() and colons block: Fix backing paths for filenames with colons block: Tweak error message related to qemu-img amend qemu-img: Fix leakage of options on error qemu-img: copy *key-secret opts when opening newly created files qemu-img: introduce --target-image-opts for 'convert' command qemu-img: fix --image-opts usage with dd command qemu-img: add support for --object with 'dd' command qemu-img: Fix documentation of convert qcow2: remove extra local_error variable mirror: Drop permissions on s->target on completion nvme: Add support for Controller Memory Buffers iotests: 147: Don't test inet6 if not available qemu-iotests: Test streaming with missing job ID stream: fix crash in stream_start() when block_job_create() fails Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-29mirror: Drop permissions on s->target on completionKevin Wolf
This fixes an assertion failure that was triggered by qemu-iotests 129 on some CI host, while the same test case didn't seem to fail on other hosts. Essentially the problem is that the blk_unref(s->target) in mirror_exit() doesn't necessarily mean that the BlockBackend goes away immediately. It is possible that the job completion was triggered nested in mirror_drain(), which looks like this: BlockBackend *target = s->target; blk_ref(target); blk_drain(target); blk_unref(target); In this case, the write permissions for s->target are retained until after blk_drain(), which makes removing mirror_top_bs fail for the active commit case (can't have a writable backing file in the chain without the filter driver). Explicitly dropping the permissions first means that the additional reference doesn't hurt and the job can complete successfully even if called from the nested blk_drain(). Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-05-24blockjob: introduce block_job_early_failPaolo Bonzini
Outside blockjob.c, block_job_unref is only used when a block job fails to start, and block_job_ref is not used at all. The reference counting thus is pretty well hidden. Introduce a separate function to be used by block jobs; because block_job_ref and block_job_unref now become static, move them earlier in blockjob.c. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170508141310.8674-4-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-04-28block: Add errp to b{lk,drv}_truncate()Max Reitz
For one thing, this allows us to drop the error message generation from qemu-img.c and blockdev.c and instead have it unified in bdrv_truncate(). Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20170328205129.15138-3-mreitz@redhat.com Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-24block: Make errp the last parameter of commit_active_startFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170421122710.15373-9-famz@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24mirror: Make errp the last parameter of mirror_start_jobFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170421122710.15373-8-famz@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-07mirror: Fix aio context of mirror_top_bsFam Zheng
It should be moved to the same context as source, before inserting to the graph. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-07block/mirror: Fix use-after-freeMax Reitz
If @bs does not have any parents, the only reference to @mirror_top_bs will be held by the BlockJob object after the bdrv_unref() following block_job_create(). However, if block_job_create() fails, this reference will not exist and @mirror_top_bs will have been deleted when we goto fail. The issue comes back at all later entries to the fail label: We delete the BlockJob object before rolling back our changes to the node graph. This means that we will delete @mirror_top_bs in the process. All in all, whenever @bs does not have any parents and we go down the fail path we will dereference @mirror_top_bs after it has been deleted. Fix this by invoking bdrv_unref() only when block_job_create() was successful and by bdrv_ref()'ing @mirror_top_bs in the fail path before deleting the BlockJob object. Finally, bdrv_unref() it at the end of the fail path after we actually no longer need it. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-24trace: Fix backwards mirror_yield parametersEric Blake
block/trace-events lists the parameters for mirror_yield consistently with other mirror events (cnt just after s, like in mirror_before_sleep; in_flight last, like in mirror_yield_in_flight). But the callers were passing parameters in the wrong order, leading to poor trace messages, including type truncation when there are more than 4G dirty sectors involved. Broken since its introduction in commit bd48bde. While touching this, ensure that all callers use the same type (uint64_t) for cnt, as a later patch will enable the compiler to do stricter type-checking. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-03-17block: Always call bdrv_child_check_perm firstFam Zheng
bdrv_child_set_perm alone is not very usable because the caller must call bdrv_child_check_perm first. This is already encapsulated conveniently in bdrv_child_try_set_perm, so remove the other prototypes from the header and fix the one wrong caller, block/mirror.c. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-13mirror: Implement .bdrv_refresh_filenameKevin Wolf
We want query-block to return the right filename, even if a mirror job put a bdrv_mirror_top on top of the actual image format driver. Let bdrv_mirror_top.bdrv_refresh_filename get the filename from its backing file. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07block: Fix error handling in bdrv_replace_in_backing_chain()Kevin Wolf
When adding an Error parameter, bdrv_replace_in_backing_chain() would become nothing more than a wrapper around change_parent_backing_link(). So make the latter public, renamed as bdrv_replace_node(), and remove bdrv_replace_in_backing_chain(). Most of the callers just remove a node from the graph that they just inserted, so they can use &error_abort, but completion of a mirror job with 'replaces' set can actually fail. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07mirror: Fix error path for dirty bitmap creationKevin Wolf
mirror_top_bs must be removed from the graph again when creating the dirty bitmap fails. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07mirror: Fix permissions for removing mirror_top_bsKevin Wolf
mirror_top_bs takes write permissions on its backing file, which can make it impossible to attach that backing file node to another parent. However, this is exactly what needs to be done in order to remove mirror_top_bs from the backing chain. So give up the write permission first. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07mirror: Fix permission problem with 'replaces'Kevin Wolf
The 'replaces' option of drive-mirror can be used to mirror a Quorum node to a new image and then let the target image replace one of the Quorum children. In order for this graph modification to succeed, the mirror job needs to lift its restrictions on the target node first before actually replacing the child. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-02-28block: Add Error parameter to bdrv_append()Kevin Wolf
Aborting on error in bdrv_append() isn't correct. This patch fixes it and lets the callers handle failures. Test case 085 needs a reference output update. This is caused by the reversed order of bdrv_set_backing_hd() and change_parent_backing_link() in bdrv_append(): When the backing file of the new node is set, the parent nodes are still pointing to the old top, so the backing blocker is now initialised with the node name rather than the BlockBackend name. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Add Error parameter to bdrv_set_backing_hd()Kevin Wolf
Not all callers of bdrv_set_backing_hd() know for sure that attaching the backing file will be allowed by the permission system. Return the error from the function rather than aborting. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28commit: Add filter-node-name to block-commitKevin Wolf
Management tools need to be able to know about every node in the graph and need a way to address them. Changing the graph structure was okay because libvirt doesn't really manage the node level yet, but future libvirt versions need to deal with both new and old version of qemu. This new option to blockdev-commit allows the client to set a node-name for the automatically inserted filter driver, and at the same time serves as a witness for a future libvirt that this version of qemu does automatically insert a filter driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28mirror: Add filter-node-name to blockdev-mirrorKevin Wolf
Management tools need to be able to know about every node in the graph and need a way to address them. Changing the graph structure was okay because libvirt doesn't really manage the node level yet, but future libvirt versions need to deal with both new and old version of qemu. This new option to blockdev-mirror allows the client to set a node-name for the automatically inserted filter driver, and at the same time serves as a witness for a future libvirt that this version of qemu does automatically insert a filter driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28mirror: Use real permissions in mirror/active commit block jobKevin Wolf
The mirror block job is mainly used for two different scenarios: Mirroring to an otherwise unused, independent target node, or for active commit where the target node is part of the backing chain of the source. Similarly to the commit block job patch, we need to insert a new filter node to keep the permissions correct during active commit. Note that one change this implies is that job->blk points to mirror_top_bs as its root now, and mirror_top_bs (rather than the actual source node) contains the bs->job pointer. This requires qemu-img commit to get the job by name now rather than just taking bs->job. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Acked-by: Max Reitz <mreitz@redhat.com>
2017-02-28blockjob: Add permissions to block_job_add_bdrv()Kevin Wolf
Block jobs don't actually do I/O through the the reference they create with block_job_add_bdrv(), but they might want to use the permisssion system to express what the block job does to intermediate nodes. This adds permissions to block_job_add_bdrv() to provide the means to request permissions. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>