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path: root/block/stream.c
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2014-01-24block: Update BlockLimits when they might have changedKevin Wolf1-0/+2
When reopening with different flags, or when backing files disappear from the chain, the limits may change. Make sure they get updated in these cases. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit@irqsave.net>
2013-11-28block/stream: Don't stream unbacked devicesMax Reitz1-0/+5
If a block device is unbacked, a streaming blockjob should immediately finish instead of beginning to try to stream, then noticing the backing file does not contain even the first sector (since it does not exist) and then finishing normally. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11qapi: make use of new BlockJobTypeFam Zheng1-1/+1
Switch the string to enum type BlockJobType in BlockJobDriver. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11blockjob: rename BlockJobType to BlockJobDriverFam Zheng1-2/+2
We will use BlockJobType as the enum type name of block jobs in QAPI, rename current BlockJobType to BlockJobDriver, which will eventually become a set of operations, similar to block drivers. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25block: Fix compiler warning (-Werror=uninitialized)Stefan Weil1-2/+3
The patch fixes a warning from gcc (Debian 4.6.3-14+rpi1) 4.6.3: block/stream.c:141:22: error: ‘copy’ may be used uninitialized in this function [-Werror=uninitialized] This is not a real bug - a better compiler would not complain. Now 'copy' has always a defined value, so the check for ret >= 0 can be removed. Signed-off-by: Stefan Weil <sw@weilnetz.de> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-06block: expect errors from bdrv_co_is_allocatedPaolo Bonzini1-1/+1
Some bdrv_is_allocated callers do not expect errors, but the fallback in qcow2.c might make other callers trip on assertion failures or infinite loops. Fix the callers to always look for errors. Cc: qemu-stable@nongnu.org Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above distinctionPaolo Bonzini1-2/+2
Now that bdrv_is_allocated detects coroutine context, the two can use the same code. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: make bdrv_co_is_allocated staticPaolo Bonzini1-2/+2
bdrv_is_allocated can detect coroutine context and go through a fast path, similar to other block layer functions. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06block: make bdrv_delete() staticFam Zheng1-1/+1
Manage BlockDriverState lifecycle with refcnt, so bdrv_delete() is no longer public and should be called by bdrv_unref() if refcnt is decreased to 0. This is an identical change because effectively, there's no multiple reference of BDS now: no caller of bdrv_ref() yet, only bdrv_new() sets bs->refcnt to 1, so all bdrv_unref() now actually delete the BDS. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22aio / timers: convert block_job_sleep_ns and co_sleep_ns to new APIAlex Bligh1-1/+1
Convert block_job_sleep_ns and co_sleep_ns to use the new timer API. Signed-off-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19block: stop relying on io_flush() in bdrv_drain_all()Stefan Hajnoczi1-1/+5
If a block driver has no file descriptors to monitor but there are still active requests, it can return 1 from .io_flush(). This is used to spin during synchronous I/O. Stop relying on .io_flush() and instead check QLIST_EMPTY(&bs->tracked_requests) to decide whether there are active requests. This is the first step in removing .io_flush() so that event loops no longer need to have the concept of synchronous I/O. Eventually we may be able to kill synchronous I/O completely by running everything in a coroutine, but that is future work. Note this patch moves bs->throttled_reqs initialization to bdrv_new() so that bdrv_requests_pending(bs) can safely access it. In practice bs is g_malloc0() so the memory is already zeroed but it's safer to initialize the queue properly. We also need to fix up block/stream.c:close_unused_images() to prevent traversing a dangling pointer while it rearranges the backing file chain. This is necessary since the new bdrv_drain_all() traverses the backing file chain. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-06-28block: Make BlockJobTypes constKevin Wolf1-1/+1
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-19block: move include files to include/block/Paolo Bonzini1-2/+2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-11aio: Get rid of qemu_aio_flush()Kevin Wolf1-1/+1
There are no remaining users, and new users should probably be using bdrv_drain_all() in the first place. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-10-24block: rename block_job_complete to block_job_completedPaolo Bonzini1-2/+2
The imperative will be used for the QMP command. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28stream: add on-error argumentPaolo Bonzini1-1/+27
This patch adds support for error management to streaming. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-28block: move job APIs to separate filesPaolo Bonzini1-0/+1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-29stream: complete early if end of backing file is reachedStefan Hajnoczi1-0/+6
It is possible to create an image that is larger than its backing file. Reading beyond the end of the backing file produces zeroes if no writes have been made to those sectors in the image file. This patch finishes streaming early when the end of the backing file is reached. Without this patch the block job hangs and continually tries to stream the first sectors beyond the end of the backing file. To reproduce the hung block job bug: $ qemu-img create -f qcow2 backing.qcow2 128M $ qemu-img create -f qcow2 -o backing_file=backing.qcow2 image.qcow2 6G $ qemu -drive if=virtio,cache=none,file=image.qcow2 (qemu) block_stream virtio0 (qemu) info block-jobs The qemu-iotests 030 streaming test still passes. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15stream: move rate limiting to a separate header filePaolo Bonzini1-29/+2
Make the code reusable. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15stream: move is_allocated_above to block.cPaolo Bonzini1-51/+2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15stream: tweak usage of bdrv_co_is_allocatedPaolo Bonzini1-26/+25
is_allocated_base has complex semantics that are not really usable outside streaming. Split the check in two parts, where the allocated state for the top bs is moved to the caller. The resulting function is more generally useful. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10block: fix warning introduced in efcc7a23Anthony Liguori1-1/+1
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-05-10stream: do not copy unallocated sectors from the basePaolo Bonzini1-14/+4
Unallocated sectors should really never be accessed by the guest, so there's no need to copy them during the streaming process. If they are read by the guest during streaming, guest-initiated copy-on-read will copy them (we're in the base == NULL case, which enables copy on read). If they are read after we disconnect the image from the base, they will read as zeroes anyway. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10stream: fix ratelimiting corner casePaolo Bonzini1-5/+5
This fixes inability to make progress in streaming if the quota is set to less than the amount of data that an I/O operation has to write. In this case, limit->dispatched + n will always be above the quota and, due to the "goto retry" to recheck cancellation and allocation, streaming will livelock. This can be reproduced with "block_job_set_speed ide0-hd0 1b". Of course, with this patch the requested limit will not be obeyed. That could be done with another patch that caps is_allocated's n argument by the slice quota. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10stream: pass new base image format to bdrv_change_backing_filePaolo Bonzini1-2/+5
When an image is modified to point to the new backing file, the backing file format is set to NULL, which means auto-probe. This is wrong, in fact it is a small security problem. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10block: wait for job callback in block_job_cancel_syncPaolo Bonzini1-4/+3
The limitation on not having I/O after cancellation cannot really be kept. Even streaming has a very small race window where you could cancel a job and have it report completion. If this window is hit, bdrv_change_backing_file() will yield and possibly cause accesses to dangling pointers etc. So, let's just assume that we cannot know exactly what will happen after the coroutine has set busy to false. We can set a very lax condition: - if we cancel the job, the coroutine won't set it to false again (and hence will not call co_sleep_ns again). - block_job_cancel_sync will wait for the coroutine to exit, which pretty much ensures no race. Instead, we track the coroutine that executes the job and put very strict conditions on what to do while it is quiescent (busy = false). First of all, the coroutine must never set busy = false while the job has been cancelled. Second, the coroutine can be reentered arbitrarily while it is quiescent, so you cannot really do anything but co_sleep_ns at that time. This condition is obeyed by the block_job_sleep_ns function. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10block: add block_job_sleep_nsPaolo Bonzini1-14/+9
This function abstracts the pretty complex semantics of the "busy" member of BlockJob. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-10block: update in-memory backing file and formatPaolo Bonzini1-11/+0
These are needed to print "info block" output correctly. QCOW2 does this because it needs it to write the header, but QED does not, and common code is the right place to do it. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-27block: add 'speed' optional parameter to block-streamStefan Hajnoczi1-2/+3
Allow streaming operations to be started with an initial speed limit. This eliminates the window of time between starting streaming and issuing block-job-set-speed. Users should use the new optional 'speed' parameter instead so that speed limits are in effect immediately when the job starts. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27block: change block-job-set-speed argument from 'value' to 'speed'Stefan Hajnoczi1-4/+4
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27block: use Error mechanism instead of -errno for block_job_set_speed()Stefan Hajnoczi1-3/+3
There are at least two different errors that can occur in block_job_set_speed(): the job might not support setting speeds or the value might be invalid. Use the Error mechanism to report the error where it occurs. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-27block: use Error mechanism instead of -errno for block_job_create()Stefan Hajnoczi1-6/+5
The block job API uses -errno return values internally and we convert these to Error in the QMP functions. This is ugly because the Error should be created at the point where we still have all the relevant information. More importantly, it is hard to add new error cases to this case since we quickly run out of -errno values without losing information. Go ahead and use Error directly and don't convert later. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2012-04-05block stream: close unused files and update ->backing_hdMarcelo Tosatti1-0/+34
Close the now unused images that were part of the previous backing file chain and adjust ->backing_hd, backing_filename and backing_format properly. Fixes https://bugzilla.redhat.com/show_bug.cgi?id=801449 Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05block: set job->speed in block_set_speedPaolo Bonzini1-1/+0
There is no need to do this in every implementation of set_speed (even though there is only one right now). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-05block: fix streaming/closing racePaolo Bonzini1-2/+4
Streaming can issue I/O while qcow2_close is running. This causes the L2 caches to become very confused or, alternatively, could cause a segfault when the streaming coroutine is reentered after closing its block device. The fix is to cancel streaming jobs when closing their underlying device. The cancellation must be synchronous, on the other hand qemu_aio_wait will not restart a coroutine that is sleeping in co_sleep. So add a flag saying whether streaming has in-flight I/O. If the busy flag is false, the coroutine is quiescent and, when cancelled, will not issue any new I/O. This protects streaming against closing, but not against deleting. We have a reference count protecting us against concurrent deletion, but I still added an assertion to ensure nothing bad happens. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26block: add support for partial streamingMarcelo Tosatti1-4/+87
Add support for streaming data from an intermediate section of the image chain (see patch and documentation for details). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26block: rate-limit streaming operationsStefan Hajnoczi1-6/+59
This patch implements rate-limiting for image streaming. If we've exceeded the bandwidth quota for a 100 ms time slice we sleep the coroutine until the next slice begins. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26block: add image streaming block jobStefan Hajnoczi1-0/+133
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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