aboutsummaryrefslogtreecommitdiff
path: root/include/block/block.h
AgeCommit message (Collapse)Author
2017-08-08block: Allow reopen rw without BDRV_O_ALLOW_RDWRKevin Wolf
BDRV_O_ALLOW_RDWR is a flag that tells whether qemu can internally reopen a node read-write temporarily because the user requested read-write for the top-level image, but qemu decided that read-only is enough for this node (a backing file). bdrv_reopen() is different, it is also used for cases where the user changed their mind and wants to update the options. There is no reason to forbid making a node read-write in that case. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: John Snow <jsnow@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 bdrv_truncate()Max Reitz
For block drivers that just pass a truncate request to the underlying protocol, we can now pass the preallocation mode instead of aborting if it is not PREALLOC_MODE_OFF. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20170613202107.10125-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: add bdrv_measure() APIStefan Hajnoczi
bdrv_measure() provides a conservative maximum for the size of a new image. This information is handy if storage needs to be allocated (e.g. a SAN or an LVM volume) ahead of time. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 20170705125738.8777-2-stefanha@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: add bdrv_can_store_new_dirty_bitmapVladimir Sementsov-Ogievskiy
This will be needed to check some restrictions before making bitmap persistent in qmp-block-dirty-bitmap-add (this functionality will be added by future patch) Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 20170628120530.31251-22-vsementsov@virtuozzo.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11block: remove all encryption handling APIsDaniel P. Berrange
Now that all encryption keys must be provided upfront via the QCryptoSecret API and associated block driver properties there is no need for any explicit encryption handling APIs in the block layer. Encryption can be handled transparently within the block driver. We only retain an API for querying whether an image is encrypted or not, since that is a potentially useful piece of metadata to report to the user. Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170623162419.26068-18-berrange@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>
2017-07-10block: Make bdrv_is_allocated() 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 on input and that *pnum is sector-aligned on return to the caller, but that can be relaxed when a later patch implements byte-based block status. Therefore, this code adds usages like DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned values, where the call might reasonbly give non-aligned results in the future; on the other hand, no rounding is needed for callers that should just continue to work with byte alignment. 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 bdrv_commit(), gets a lot simpler because it no longer has to mess with sectors; also, it is now possible to pass NULL if the caller does not care how much of the image is allocated beyond the initial offset. Leave comments where we can further simplify once a later patch eliminates the need for sector-aligned requests through bdrv_is_allocated(). For ease of review, bdrv_is_allocated_above() will be tackled separately. Signed-off-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10block: Drop unused bdrv_round_sectors_to_clusters()Eric Blake
Now that the last user [mirror_iteration()] has converted to using bytes, we no longer need a function to round sectors to clusters. 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>
2017-06-30block: Add BDRV_BLOCK_EOF to bdrv_get_block_status()Eric Blake
Just as the block layer already sets BDRV_BLOCK_ALLOCATED as a shortcut for subsequent operations, there are also some optimizations that are made easier if we can quickly tell that *pnum will advance us to the end of a file, via a new BDRV_BLOCK_EOF which gets set by the block layer. This just plumbs up the new bit; subsequent patches will make use of it. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20170505021500.19315-2-eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Fam Zheng <famz@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>
2017-06-26block: Remove bdrv_aio_readv/writev/flush()Kevin Wolf
These functions are unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-06-16block: access wakeup with atomic opsPaolo Bonzini
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20170605123908.18777-6-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-05-11block: Update comments on BDRV_BLOCK_* meaningsEric Blake
We had some conflicting documentation: a nice 8-way table that described all possible combinations of DATA, ZERO, and OFFSET_VALID, contrasted with text that implied that OFFSET_VALID always meant raw data could be read directly. Furthermore, the text refers a lot to bs->file, even though the interface was updated back in 67a0fd2a to let the driver pass back a specific BDS (not necessarily bs->file). As the 8-way table is the intended semantics, simplify the rest of the text to get rid of the confusion. ALLOCATED is always set by the block layer for convenience (drivers do not have to worry about it). RAW is used only internally, but by more than the raw driver. Document these additional items on the driver callback. Suggested-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170507000552.20847-4-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11block: Fix write/resize permissions for inactive imagesKevin Wolf
Format drivers for inactive nodes don't need write/resize permissions on their bs->file and can share write/resize with another VM (in fact, this is the whole point of keeping images inactive). Represent this fact in the op blocker system, so that image locking does the right thing without special-casing inactive images. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-11block: New BdrvChildRole.activate() for blk_resume_after_migration()Kevin Wolf
Instead of manually calling blk_resume_after_migration() in migration code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend activation with cache invalidation into a single function. This is achieved with a new callback in BdrvChildRole that is called by bdrv_invalidate_cache_all(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-11block: Add, parse and store "force-share" optionFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-11block: Make bdrv_perm_names publicFam Zheng
It can be used outside of block.c for making user friendly messages. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@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: introduce bdrv_can_set_read_only()Jeff Cody
Introduce check function for setting read_only flags. Will return < 0 on error, with appropriate Error value set. Does not alter any flags. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: e2bba34ac3bc76a0c42adc390413f358ae0566e8.1491597120.git.jcody@redhat.com
2017-04-24block: do not set BDS read_only if copy_on_read enabledJeff Cody
A few block drivers will set the BDS read_only flag from their .bdrv_open() function. This means the bs->read_only flag could be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ flag check occurs prior to the call to bdrv->bdrv_open(). This adds an error return to bdrv_set_read_only(), and an error will be return if we try to set the BDS to read_only while copy_on_read is enabled. This patch also changes the behavior of vvfat. Before, vvfat could override the drive 'readonly' flag with its own, internal 'rw' flag. For instance, this -drive parameter would result in a writable image: "-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on" This is not correct. Now, attempting to use the above -drive parameter will result in an error (i.e., 'rw' is incompatible with 'readonly=on'). Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
2017-04-24block: add bdrv_set_read_only() helper functionJeff Cody
We have a helper wrapper for checking for the BDS read_only flag, add a helper wrapper to set the read_only flag as well. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
2017-04-24block: Make errp the last parameter of bdrv_img_createFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170421122710.15373-6-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>
2017-04-18block: Drain BH in bdrv_drained_beginFam Zheng
During block job completion, nothing is preventing block_job_defer_to_main_loop_bh from being called in a nested aio_poll(), which is a trouble, such as in this code path: qmp_block_commit commit_active_start bdrv_reopen bdrv_reopen_multiple bdrv_reopen_prepare bdrv_flush aio_poll aio_bh_poll aio_bh_call block_job_defer_to_main_loop_bh stream_complete bdrv_reopen block_job_defer_to_main_loop_bh is the last step of the stream job, which should have been "paused" by the bdrv_drained_begin/end in bdrv_reopen_multiple, but it is not done because it's in the form of a main loop BH. Similar to why block jobs should be paused between drained_begin and drained_end, BHs they schedule must be excluded as well. To achieve this, this patch forces draining the BH in BDRV_POLL_WHILE. As a side effect this fixes a hang in block_job_detach_aio_context during system_reset when a block job is ready: #0 0x0000555555aa79f3 in bdrv_drain_recurse #1 0x0000555555aa825d in bdrv_drained_begin #2 0x0000555555aa8449 in bdrv_drain #3 0x0000555555a9c356 in blk_drain #4 0x0000555555aa3cfd in mirror_drain #5 0x0000555555a66e11 in block_job_detach_aio_context #6 0x0000555555a62f4d in bdrv_detach_aio_context #7 0x0000555555a63116 in bdrv_set_aio_context #8 0x0000555555a9d326 in blk_set_aio_context #9 0x00005555557e38da in virtio_blk_data_plane_stop #10 0x00005555559f9d5f in virtio_bus_stop_ioeventfd #11 0x00005555559fa49b in virtio_bus_stop_ioeventfd #12 0x00005555559f6a18 in virtio_pci_stop_ioeventfd #13 0x00005555559f6a18 in virtio_pci_reset #14 0x00005555559139a9 in qdev_reset_one #15 0x0000555555916738 in qbus_walk_children #16 0x0000555555913318 in qdev_walk_children #17 0x0000555555916738 in qbus_walk_children #18 0x00005555559168ca in qemu_devices_reset #19 0x000055555581fcbb in pc_machine_reset #20 0x00005555558a4d96 in qemu_system_reset #21 0x000055555577157a in main_loop_should_exit #22 0x000055555577157a in main_loop #23 0x000055555577157a in main The rationale is that the loop in block_job_detach_aio_context cannot make any progress in pausing/completing the job, because bs->in_flight is 0, so bdrv_drain doesn't process the block_job_defer_to_main_loop BH. With this patch, it does. Reported-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170418143044.12187-3-famz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Tested-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2017-04-11block: Introduce bdrv_coroutine_enterFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11block: Make bdrv_parent_drained_begin/end publicFam Zheng
Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-07block: Ignore guest dev permissions during incoming migrationKevin Wolf
Usually guest devices don't like other writers to the same image, so they use blk_set_perm() to prevent this from happening. In the migration phase before the VM is actually running, though, they don't have a problem with writes to the image. On the other hand, storage migration needs to be able to write to the image in this phase, so the restrictive blk_set_perm() call of qdev devices breaks it. This patch flags all BlockBackends with a qdev device as blk->disable_perm during incoming migration, which means that the requested permissions are stored in the BlockBackend, but not actually applied to its root node yet. Once migration has finished and the VM should be resumed, the permissions are applied. If they cannot be applied (e.g. because the NBD server used for block migration hasn't been shut down), resuming the VM fails. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Kashyap Chamarthy <kchamart@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>
2017-02-28block: 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>
2017-02-28block: Add BDRV_O_RESIZE for blk_new_open()Kevin Wolf
blk_new_open() is a convenience function that processes flags rather than QDict options as a simple way to just open an image file. In order to keep it convenient in the future, it must automatically request the necessary permissions. This can easily be inferred from the flags for read and write, but we need another flag that tells us whether to get the resize permission. We can't just always request it because that means that no block jobs can run on the resulting BlockBackend (which is something that e.g. qemu-img commit wants to do), but we also can't request it never because most of the .bdrv_create() implementations call blk_truncate(). The solution is to introduce another flag that is passed by all users that want to resize the image. 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 argument to bdrv_attach_child()Kevin Wolf
It will have to return an error soon, so prepare the callers for it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add op blocker permission constantsKevin Wolf
This patch defines the permission categories that will be used by the new op blocker system. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-24block: Add bdrv_new_open_driver()Kevin Wolf
This function allows to create more or less normal BlockDriverStates even for BlockDrivers that aren't globally registered (e.g. helper filters for block jobs). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Pass BdrvChild to bdrv_truncate()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-01-27block: Fix target variable of BLKSECTGET ioctlEric Farman
Commit 6f6071745bd0 ("raw-posix: Fetch max sectors for host block device") introduced a routine to call the kernel BLKSECTGET ioctl, which stores the result back to user space. However, the size of the data returned depends on the routine handling the ioctl. The (compat_)blkdev_ioctl returns a short, while sg_ioctl returns an int. Thus, on big-endian systems, we can find ourselves accidentally shifting the result to a much larger value. (On s390x, a short is 16 bits while an int is 32 bits.) Also, the two ioctl handlers return values in different scales (block returns sectors, while sg returns bytes), so some tweaking of the outputs is required such that hdev_get_max_transfer_length returns a value in a consistent set of units. Signed-off-by: Eric Farman <farman@linux.vnet.ibm.com> Message-Id: <20170120162527.66075-3-farman@linux.vnet.ibm.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-16block: get rid of bdrv_io_unplugged_begin/endPaolo Bonzini
bdrv_io_plug and bdrv_io_unplug are only called (via their BlockBackend equivalents) after starting asynchronous I/O. bdrv_drain is not going to be called while they are running, because---even if a coroutine runs for some reason---it will only drain in the next iteration of the event loop through bdrv_co_yield_to_drain. So this mechanism is unnecessary, get rid of it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161129113334.605-1-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-11-01blockjobs: split interface into public/private, Part 1John Snow
To make it a little more obvious which functions are intended to be public interface and which are intended to be for use only by jobs themselves, split the interface into "public" and "private" files. Convert blockjobs (e.g. block/backup) to using the private interface. Leave blockdev and others on the public interface. There are remaining uses of private state by qemu-img, and several cases in blockdev.c and block/io.c where we grab job->blk for the purposes of acquiring an AIOContext. These will be corrected in future patches. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-7-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-10-31block: Add bdrv_drain_all_{begin,end}()Alberto Garcia
bdrv_drain_all() doesn't allow the caller to do anything after all pending requests have been completed but before block jobs are resumed. This patch splits bdrv_drain_all() into _begin() and _end() for that purpose. It also adds aio_{disable,enable}_external() calls to disable external clients in the meantime. An important restriction of this split is that no new block jobs or BlockDriverStates can be created between the bdrv_drain_all_begin() and bdrv_drain_all_end() calls. This is not a concern now because we'll only be using this in bdrv_reopen_multiple(), but it must be dealt with if we ever have other uses cases in the future. Signed-off-by: Alberto Garcia <berto@igalia.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-28block: only call aio_poll on the current thread's AioContextPaolo Bonzini
aio_poll is not thread safe; for example bdrv_drain can hang if the last in-flight I/O operation is completed in the I/O thread after the main thread has checked bs->in_flight. The bug remains latent as long as all of it is called within aio_context_acquire/aio_context_release, but this will change soon. To fix this, if bdrv_drain is called from outside the I/O thread, signal the main AioContext through a dummy bottom half. The event loop then only runs in the I/O thread. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: prepare bdrv_reopen_multiple to release AioContextPaolo Bonzini
After the next patch bdrv_drain_all will have to be called without holding any AioContext. Prepare to do this by adding an AioContext argument to bdrv_reopen_multiple. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28block: introduce BDRV_POLL_WHILEPaolo Bonzini
We want the BDS event loop to run exclusively in the iothread that owns the BDS's AioContext. This macro will provide the synchronization between the two event loops; for now it just wraps the common idiom of a while loop around aio_poll. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-8-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-27block: Remove bdrv_aio_ioctl()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_ioctl()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Use blk_co_ioctl() for all BB level ioctlsKevin Wolf
All read/write functions already have a single coroutine-based function on the BlockBackend level through which all requests go (no matter what API style the external caller used) and which passes the requests down to the block node level. This patch exports a bdrv_co_ioctl() function and uses it to extend this mode of operation to ioctls. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-10-27block: Remove bdrv_aio_pdiscard()Kevin Wolf
It is unused now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-09-29block: Move 'discard' option to bdrv_open_common()Kevin Wolf
This enables its use for nested child nodes. The compatibility between the 'discard' and 'detect-zeroes' setting is checked in bdrv_open_common() now as the former setting isn't available before calling bdrv_open() any more. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-29block: reintroduce bdrv_flush_allJohn Snow
Commit fe1a9cbc moved the flush_all routine from the bdrv layer to the block-backend layer. In doing so, however, the semantics of the routine changed slightly such that flush_all now used blk_flush instead of bdrv_flush. blk_flush can fail if the attached device model reports that it is not "available," (i.e. the tray is open.) This changed the semantics of flush_all such that it can now fail for e.g. open CDROM drives. Reintroduce bdrv_flush_all to regain the old semantics without having to alter the behavior of blk_flush or blk_flush_all, which are already 'doing the right thing.' Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23block: Add "read-only" to the options QDictAlberto Garcia
This adds the "read-only" option to the QDict. One important effect of this change is that when a child inherits options from its parent, the existing "read-only" mode can be preserved if it was explicitly set previously. This addresses scenarios like this: [E] <- [D] <- [C] <- [B] <- [A] In this case, if we reopen [D] with read-only=off, and later reopen [B], then [D] will not inherit read-only=on from its parent during the bdrv_reopen_queue_child() stage. The BDRV_O_RDWR flag is not removed yet, but its keep in sync with the value of the "read-only" option. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>