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path: root/block/stream.c
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2012-05-10stream: pass new base image format to bdrv_change_backing_filePaolo Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Hajnoczi
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 Hajnoczi
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 Hajnoczi
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 Hajnoczi
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 Tosatti
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 Bonzini
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 Bonzini
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 Tosatti
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 Hajnoczi
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 Hajnoczi
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>