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* block: Introduce .bdrv_co_preadv/pwritev BlockDriver functionKevin Wolf2016-05-121-6/+22
| | | | | | | | | | | | Many parts of the block layer are already byte granularity. The block driver interface, however, was still missing an interface that allows making use of this. This patch introduces a new BlockDriver interface, which is based on coroutines, vectored, has flags and uses a byte granularity. This is now the preferred interface for new drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* block: Rename bdrv_co_do_preadv/writev to bdrv_co_preadv/writevKevin Wolf2016-05-121-12/+12
| | | | | | | | | | It used to be an internal helper function just for implementing bdrv_co_do_readv/writev(), but now that it's a public interface, it deserves a name without "do" in it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* block: Support AIO drivers in bdrv_driver_preadv/pwritev()Kevin Wolf2016-05-121-74/+52Star
| | | | | | | | | | | | Instead of registering emulation functions as .bdrv_co_writev, just directly check whether the function is there or not, and use the AIO interface if it isn't. This makes the read/write functions more consistent with how things are done in other places (flush, discard, etc.) Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* block: Introduce bdrv_driver_pwritev()Kevin Wolf2016-05-121-15/+36
| | | | | | | | | | | | | | This is a function that simply calls into the block driver for doing a write, providing the byte granularity interface we want to eventually have everywhere, and using whatever interface that driver supports. This one is a bit more interesting than the version for reads: It adds support for .bdrv_co_writev_flags() everywhere, so that drivers implementing this function can drop .bdrv_co_writev() now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* block: Introduce bdrv_driver_preadv()Kevin Wolf2016-05-121-7/+23
| | | | | | | | | | | | This is a function that simply calls into the block driver for doing a read, providing the byte granularity interface we want to eventually have everywhere, and using whatever interface that driver supports. For now, this is just a wrapper for calling bs->drv->bdrv_co_readv(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* block: plug whole tree at once, introduce bdrv_io_unplugged_begin/endPaolo Bonzini2016-05-121-18/+58
| | | | | | | | | | | | | | Extract the handling of io_plug "depth" from linux-aio.c and let the main bdrv_drain loop do nothing but wait on I/O. Like the two newly introduced functions, bdrv_io_plug and bdrv_io_unplug now operate on all children. The visit order is now symmetrical between plug and unplug, making it possible for formats to implement plug/unplug. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: introduce bdrv_no_throttling_begin/endPaolo Bonzini2016-05-121-12/+21
| | | | | | | | | | | Extract the handling of throttling from bdrv_flush_io_queue. These new functions will soon become BdrvChildRole callbacks, as they can be generalized to "beginning of drain" and "end of drain". Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: extract bdrv_drain_poll/bdrv_co_yield_to_drain from ↵Paolo Bonzini2016-05-121-12/+23
| | | | | | | | | | | | bdrv_drain/bdrv_co_drain Do not call bdrv_drain_recurse twice in bdrv_co_drain. A small tweak to the logic in Fam's patch, which is harmless since no one implements bdrv_drain anyway. But better get it right. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: move restarting of throttled reqs to block/throttle-groups.cPaolo Bonzini2016-05-121-14/+1Star
| | | | | | | | | | We want to remove throttled_reqs from block/io.c. This is the easy part---hide the handling of throttled_reqs during disable/enable of throttling within throttle-groups.c. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: make bdrv_start_throttled_reqs return voidPaolo Bonzini2016-05-121-6/+2Star
| | | | | | | | | The return value is unused and I am not sure why it would be useful. Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Don't disable I/O throttling on sync requestsKevin Wolf2016-05-121-11/+0Star
| | | | | | | | | | | | | | | | | | We had to disable I/O throttling with synchronous requests because we didn't use to run timers in nested event loops when the code was introduced. This isn't true any more, and throttling works just fine even when using the synchronous API. The removed code is in fact dead code since commit a8823a3b ('block: Use blk_co_pwritev() for blk_write()') because I/O throttling can only be set on the top layer, but BlockBackend always uses the coroutine interface now instead of using the sync API emulation in block.c. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <1458660792-3035-2-git-send-email-kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Fix bdrv_drain in coroutineFam Zheng2016-04-111-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the nested aio_poll() in coroutine is a bad idea. This patch replaces the aio_poll loop in bdrv_drain with a BH, if called in coroutine. For example, the bdrv_drain() in mirror.c can hang when a guest issued request is pending on it in qemu_co_mutex_lock(). Mirror coroutine in this case has just finished a request, and the block job is about to complete. It calls bdrv_drain() which waits for the other coroutine to complete. The other coroutine is a scsi-disk request. The deadlock happens when the latter is in turn pending on the former to yield/terminate, in qemu_co_mutex_lock(). The state flow is as below (assuming a qcow2 image): mirror coroutine scsi-disk coroutine ------------------------------------------------------------- do last write qcow2:qemu_co_mutex_lock() ... scsi disk read tracked request begin qcow2:qemu_co_mutex_lock.enter qcow2:qemu_co_mutex_unlock() bdrv_drain while (has tracked request) aio_poll() In the scsi-disk coroutine, the qemu_co_mutex_lock() will never return because the mirror coroutine is blocked in the aio_poll(blocking=true). With this patch, the added qemu_coroutine_yield() allows the scsi-disk coroutine to make progress as expected: mirror coroutine scsi-disk coroutine ------------------------------------------------------------- do last write qcow2:qemu_co_mutex_lock() ... scsi disk read tracked request begin qcow2:qemu_co_mutex_lock.enter qcow2:qemu_co_mutex_unlock() bdrv_drain.enter > schedule BH > qemu_coroutine_yield() > qcow2:qemu_co_mutex_lock.return > ... tracked request end ... (resumed from BH callback) bdrv_drain.return ... Reported-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1459855253-5378-2-git-send-email-famz@redhat.com Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Introduce bdrv_co_writev_flags()Kevin Wolf2016-03-301-1/+8
| | | | | | | | This function will allow drivers to implement BDRV_REQ_FUA natively instead of sending a separate flush after the write. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* block: Move enable_write_cache to BB levelKevin Wolf2016-03-301-1/+1
| | | | | | | | | | | | | | Whether a write cache is used or not is a decision that concerns the user (e.g. the guest device) rather than the backend. It was already logically part of the BB level as bdrv_move_feature_fields() always kept it on top of the BDS tree; with this patch, the core of it (the actual flag and the additional flushes) is also implemented there. Direct callers of bdrv_open() must pass BDRV_O_CACHE_WB now if bs doesn't have a BlockBackend attached. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* block: Handle flush error in bdrv_pwrite_sync()Kevin Wolf2016-03-301-3/+3
| | | | | | | | | | | We don't want to silently ignore a flush error. Also, there is little point in avoiding the flush for writethrough modes and once WCE is moved to the BB layer, we definitely need the flush here because bdrv_pwrite() won't involve one any more. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* block: add flush callbackPavel Dovgalyuk2016-03-301-0/+7
| | | | | | | | | | This patch adds callback for flush request. This callback is responsible for flushing whole block devices stack. bdrv_flush function does not proceed to underlying devices. It should be performed by this callback function, if needed. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: add flag to indicate that no I/O will be performedDaniel P. Berrange2016-03-301-0/+2
| | | | | | | | | | | | | | | | | When opening an image it is useful to know whether the caller intends to perform I/O on the image or not. In the case of encrypted images this will allow the block driver to avoid having to prompt for decryption keys when we merely want to query header metadata about the image. eg qemu-img info This flag is enforced at the top level only, since even if we don't want todo I/O on the 'qcow2' file payload, the underlying 'file' driver will still need todo I/O to read the qcow2 header, for example. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* util: move declarations out of qemu-common.hVeronia Bahaa2016-03-221-0/+1
| | | | | | | | | | Move declarations out of qemu-common.h for functions declared in utils/ files: e.g. include/qemu/path.h for utils/path.c. Move inline functions out of qemu-common.h and into new files (e.g. include/qemu/bcd.h) Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster2016-03-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* block: Pull up blk_read_unthrottled() implementationKevin Wolf2016-03-171-14/+0Star
| | | | | | | Use blk_read(), so that it goes through blk_co_preadv() like all read requests from the BB to the BDS. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Use blk_co_pwritev() for blk_write()Kevin Wolf2016-03-171-4/+1Star
| | | | Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Use blk_co_preadv() for blk_read()Kevin Wolf2016-03-171-4/+1Star
| | | | | | | | This patch introduces blk_co_preadv() as a central function on the BlockBackend level that is supposed to handle all read requests from the BB to its root BDS eventually. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Move some bdrv_*_all() functions to BBMax Reitz2016-03-171-20/+0Star
| | | | | | | Move bdrv_commit_all() and bdrv_flush_all() to the BlockBackend level. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: add missing call to bdrv_drain_recursePaolo Bonzini2016-02-091-0/+1
| | | | | | | | | | This is also needed in bdrv_drain_all, not just in bdrv_drain. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1450867706-19860-3-git-send-email-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Use returned *file in bdrv_co_get_block_statusFam Zheng2016-02-021-2/+2
| | | | | | | | | Now that all drivers return the right "file" pointer, we can use it. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1453780743-16806-14-git-send-email-famz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* block: Add "file" output parameter to block status query functionsFam Zheng2016-02-021-12/+28
| | | | | | | | | | | | | | | | | | The added parameter can be used to return the BDS pointer which the valid offset is referring to. Its value should be ignored unless BDRV_BLOCK_OFFSET_VALID in ret is set. Until block drivers fill in the right value, let's clear it explicitly right before calling .bdrv_get_block_status. The "bs->file" condition in bdrv_co_get_block_status is kept now to keep iotest case 102 passing, and will be fixed once all drivers return the right file pointer. Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1453780743-16806-2-git-send-email-famz@redhat.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* block: Rename BDRV_O_INCOMING to BDRV_O_INACTIVEKevin Wolf2016-01-201-2/+2
| | | | | | | | | | | | Instead of covering only the state of images on the migration destination before the migration is completed, the flag will also cover the state of images on the migration source after completion. This common state implies that the image is technically still open, but no writes will happen and any cached contents will be reloaded from disk if and when the image leaves this state. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
* block: Assert no write requests under BDRV_O_INCOMINGKevin Wolf2016-01-201-0/+2
| | | | | | | | | As long as BDRV_O_INCOMING is set, the image file is only opened so we have a file descriptor for it. We're definitely not supposed to modify the image, it's still owned by the migration source. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
* block: Clean up includesPeter Maydell2016-01-201-0/+1
| | | | | | | | | | | Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: replace IOV_MAX with BlockLimits.max_iovStefan Hajnoczi2015-12-221-1/+2
| | | | | | | | Request merging must not result in a huge request that exceeds the maximum number of iovec elements. Use BlockLimits.max_iov instead of hardcoding IOV_MAX. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: add BlockLimits.max_iov fieldStefan Hajnoczi2015-12-221-0/+7
| | | | | | | | | | The maximum number of struct iovec elements depends on the BlockDriverState. The raw-posix and iSCSI protocols have a maximum of IOV_MAX but others could have different values. Cc: Peter Lieven <pl@kamp.de> Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: fix bdrv_ioctl called from coroutinePaolo Bonzini2015-12-181-3/+4
| | | | | | | | | | When called from a coroutine, bdrv_ioctl must be asynchronous just like e.g. bdrv_flush. The code was incorrectly making it synchronous, fix it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Don't wait serialising for non-COR read requestsFam Zheng2015-12-031-5/+7
| | | | | | | | | | | | | | | The assertion problem was noticed in 06c3916b35a, but it wasn't completely fixed, because even though the req is not marked as serialising, it still gets serialised by wait_serialising_requests against other serialising requests, which could lead to the same assertion failure. Fix it by even more explicitly skipping the serialising for this specific case. Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1448962590-2842-2-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Introduce BlockDriver.bdrv_drain callbackFam Zheng2015-11-121-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | Drivers can have internal request sources that generate IO, like the need_check_timer in QED. Since we want quiesced periods that contain nested event loops in block layer, we need to have a way to disable such event sources. Block drivers must implement the "bdrv_drain" callback if it has any internal sources that can generate I/O activity, like a timer or a worker thread (even in a library) that can schedule QEMUBH in an asynchronous callback. Update the comments of bdrv_drain and bdrv_drained_begin accordingly. Like bdrv_requests_pending(), we should consider all the children of bs. Before, the while loop just works, as bdrv_requests_pending() already tracks its children; now we mustn't miss the callback, so recurse down explicitly. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1447064214-29930-9-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Emulate bdrv_ioctl with bdrv_aio_ioctl and track bothFam Zheng2015-11-121-9/+92
| | | | | | | | | | | | | Currently all drivers that support .bdrv_aio_ioctl also implement .bdrv_ioctl redundantly. To track ioctl requests in block layer it is easier if we unify the two paths, because we'll need to run it in a coroutine, as required by tracked_request_begin. While we're at it, use .bdrv_aio_ioctl plus aio_poll() to emulate bdrv_ioctl(). Signed-off-by: Fam Zheng <famz@redhat.com> Message-id: 1447064214-29930-7-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Track discard requestsFam Zheng2015-11-121-3/+10
| | | | | | | | | | | Both bdrv_discard and bdrv_aio_discard will call into bdrv_co_discard, so add tracked_request_begin/end calls around the loop. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1447064214-29930-4-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Track flush requestsFam Zheng2015-11-121-3/+8
| | | | | | | | | | | | Both bdrv_flush and bdrv_aio_flush eventually call bdrv_co_flush, add tracked_request_begin and tracked_request_end pair in that function so that all flush requests are now tracked. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1447064214-29930-3-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Add more types for tracked requestFam Zheng2015-11-121-4/+5
| | | | | | | | | | | We'll track more request types besides read and write, change the boolean field to an enum. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1447064214-29930-2-git-send-email-famz@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Consider all child nodes in bdrv_requests_pending()Kevin Wolf2015-10-291-5/+8
| | | | | | | | | | | | | | | The function manually recursed into bs->file and bs->backing to check whether there were any requests pending, but it ignored other children. There's no need to special case file and backing here, so just replace these two explicit recursions by a loop recursing for all child nodes. Reported-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1446029211-27148-1-git-send-email-kwolf@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Introduce "drained begin/end" APIFam Zheng2015-10-231-0/+17
| | | | | | | | The semantics is that after bdrv_drained_begin(bs), bs will not get new external requests until the matching bdrv_drained_end(bs). Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Move BlockAcctStats into BlockBackendMax Reitz2015-10-231-1/+5
| | | | | | | | | | | | As the comment above bdrv_get_stats() says, BlockAcctStats is something which belongs to the device instead of each BlockDriverState. This patch therefore moves it into the BlockBackend. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block: Remove wr_highest_sector from BlockAcctStatsMax Reitz2015-10-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | BlockAcctStats contains statistics about the data transferred from and to the device; wr_highest_sector does not fit in with the rest. Furthermore, those statistics are supposed to be specific for a certain device and not necessarily for a BDS (see the comment above bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather important information to know for each BDS. When BlockAcctStats is finally removed from the BDS, we will want to keep wr_highest_sector in the BDS. Finally, wr_highest_sector is renamed to wr_highest_offset and given the appropriate meaning. Externally, it is represented as an offset so there is no point in doing something different internally. Its definition is changed to match that in qapi/block-core.json which is "the offset after the greatest byte written to". Doing so should not cause any harm since if external programs tried to calculate the volume usage by (wr_highest_offset + 512) / volume_size, after this patch they will just assume the volume to be full slightly earlier than before. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* block/io: Make bdrv_requests_pending() publicKevin Wolf2015-10-161-1/+1
| | | | | | | | 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>
* block: Convert bs->backing_hd to BdrvChildKevin Wolf2015-10-161-12/+12
| | | | | | | | | | | | | | | 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>
* block: Convert bs->file to BdrvChildKevin Wolf2015-10-161-25/+25
| | | | | | | | | | | 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>
* block: switch from g_slice allocator to mallocPaolo Bonzini2015-10-121-2/+2
| | | | | | | | Simplify memory allocation by sticking with a single API. GSlice is not that fast anyway (tcmalloc/jemalloc are better). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Introduce a new API bdrv_co_no_copy_on_readv()Wen Congyang2015-09-251-1/+11
| | | | | | | | | In some cases, we need to disable copy-on-read, and just read the data. Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Message-id: 1441682913-14320-2-git-send-email-wency@cn.fujitsu.com Signed-off-by: Jeff Cody <jcody@redhat.com>
* block: update bdrv_drain_all()/bdrv_drain() commentsStefan Hajnoczi2015-07-071-10/+10
| | | | | | | | | | | | | | | | | | | | | | | The doc comments for bdrv_drain_all() and bdrv_drain() are outdated: * The bdrv_drain() comment is a poor man's bdrv_lock()/bdrv_unlock() which Fam Zheng is currently developing. Unfortunately this warning was never really enough because devices keep submitting I/O and op blockers don't prevent that. * The bdrv_drain_all() comment is still partially correct but reflects the nature of the implementation rather than API documentation. Do make it clear that bdrv_drain() is only appropriate within an AioContext. For anything spanning AioContexts you need bdrv_drain_all(). Cc: Markus Armbruster <armbru@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1435854281-6078-1-git-send-email-stefanha@redhat.com
* block: remove redundant check before g_slist_find()Alberto Garcia2015-07-021-1/+1
| | | | | | | | | | An empty GSList is represented by a NULL pointer, therefore it's a perfectly valid argument for g_slist_find() and there's no need to make any additional check. Signed-off-by: Alberto Garcia <berto@igalia.com> Message-id: 1435583533-5758-1-git-send-email-berto@igalia.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* block: Fix dirty bitmap in bdrv_co_discardFam Zheng2015-07-021-2/+2
| | | | | | | | | | | | | | | | | | Unsetting dirty globally with discard is not very correct. The discard may zero out sectors (depending on can_write_zeroes_with_unmap), we should replicate this change to destination side to make sure that the guest sees the same data. Calling bdrv_reset_dirty also troubles mirror job because the hbitmap iterator doesn't expect unsetting of bits after current position. So let's do it the opposite way which fixes both problems: set the dirty bits if we are to discard it. Reported-by: wangxiaolong@ucloud.cn Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>