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2014-08-22block: use bdrv_nb_sectors in bdrv_is_allocated_abovebdrv-getlength-conversionPeter Wu1-1/+7
The difference is that bdrv_nb_sectors() may do a lookup for variable-sized disks. This gets rid of another direct user of total_sectors. Signed-off-by: Peter Wu <peter@lekensteyn.nl>
2014-08-22block: convert internal refresh_total_sectors to use bytesPeter Wu1-9/+10
Make bdrv_nv_sectors() handle sector calculation from bytes instead of relying on refresh_total_sectors. This prepares for the removal of bs->total_sectors. Signed-off-by: Peter Wu <peter@lekensteyn.nl>
2014-08-22block: do not directly set total_sectorsPeter Wu1-4/+18
To prepare for expressing block sizes in bytes instead of sector counts, this patch replaces all direct assignments of bs->total_sectors. This converts the expression `bs->total_sectors = X` (where X is sector count) to `bdrv_setlength(bs, BDRV_SECTOR_SIZE * X)`. Expressions such as `bs->total_sectors = Y / 512` are changed to `bdrv_setlength(bs, BDRV_SECTOR_SIZE * (Y / 512))` to account for the floor division change. If these conditions can be relaxed, it will be done in the future. Signed-off-by: Peter Wu <peter@lekensteyn.nl>
2014-08-20block: Add bdrv_refresh_filename()Max Reitz1-0/+135
Some block devices may not have a filename in their BDS; and for some, there may not even be a normal filename at all. To work around this, add a function which tries to construct a valid filename for the BDS.filename field. If a filename exists or a block driver is able to reconstruct a valid filename (which is placed in BDS.exact_filename), this can directly be used. If no filename can be constructed, we can still construct an options QDict which is then converted to a JSON object and prefixed with the "json:" pseudo protocol prefix. The QDict is placed in BDS.full_open_options. For most block drivers, this process can be done automatically; those that need special handling may define a .bdrv_refresh_filename() method to fill BDS.exact_filename and BDS.full_open_options themselves. Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-20block: Use g_new() & friends where that makes obvious senseMarkus Armbruster1-7/+7
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer, for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. Patch created with Coccinelle, with two manual changes on top: * Add const to bdrv_iterate_format() to keep the types straight * Convert the allocation in bdrv_drop_intermediate(), which Coccinelle inexplicably misses Coccinelle semantic patch: @@ type T; @@ -g_malloc(sizeof(T)) +g_new(T, 1) @@ type T; @@ -g_try_malloc(sizeof(T)) +g_try_new(T, 1) @@ type T; @@ -g_malloc0(sizeof(T)) +g_new0(T, 1) @@ type T; @@ -g_try_malloc0(sizeof(T)) +g_try_new0(T, 1) @@ type T; expression n; @@ -g_malloc(sizeof(T) * (n)) +g_new(T, n) @@ type T; expression n; @@ -g_try_malloc(sizeof(T) * (n)) +g_try_new(T, n) @@ type T; expression n; @@ -g_malloc0(sizeof(T) * (n)) +g_new0(T, n) @@ type T; expression n; @@ -g_try_malloc0(sizeof(T) * (n)) +g_try_new0(T, n) @@ type T; expression p, n; @@ -g_realloc(p, sizeof(T) * (n)) +g_renew(T, p, n) @@ type T; expression p, n; @@ -g_try_realloc(p, sizeof(T) * (n)) +g_try_renew(T, p, n) Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15block: Catch !bs->drv in bdrv_check()Max Reitz1-0/+3
qemu-img check calls bdrv_check() twice if the first run repaired some inconsistencies. If the first run however again triggered corruption prevention (on qcow2) due to very bad inconsistencies, bs->drv may be NULL afterwards. Thus, bdrv_check() should check whether bs->drv is set. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15block: Handle failure for potentially large allocationsKevin Wolf1-7/+27
Some code in the block layer makes potentially huge allocations. Failure is not completely unexpected there, so avoid aborting qemu and handle out-of-memory situations gracefully. This patch addresses bounce buffer allocations in block.c. While at it, convert bdrv_commit() from plain g_malloc() to qemu_try_blockalign(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Introduce qemu_try_blockalign()Kevin Wolf1-0/+13
This function returns NULL instead of aborting when an allocation fails. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-08-15block: allow bdrv_unref() to be passed NULL pointersJeff Cody1-0/+3
If bdrv_unref() is passed a NULL BDS pointer, it is safe to exit with no operation. This will allow cleanup code to blindly call bdrv_unref() on a BDS that has been initialized to NULL. Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-15block: bump coroutine pool size for drivesStefan Hajnoczi1-0/+6
When a BlockDriverState is associated with a storage controller DeviceState we expect guest I/O. Use this opportunity to bump the coroutine pool size by 64. This patch ensures that the coroutine pool size scales with the number of drives attached to the guest. It should increase coroutine pool usage (which makes qemu_coroutine_create() fast) without hogging too much memory when fewer drives are attached. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-08-15block: Avoid bdrv_get_geometry() where errors should be detectedMarkus Armbruster1-3/+8
bdrv_get_geometry() hides errors. Use bdrv_nb_sectors() or bdrv_getlength() instead where that's obviously inappropriate. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Drop superfluous aligning of bdrv_getlength()'s valueMarkus Armbruster1-1/+0
It returns a multiple of the sector size. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Use bdrv_nb_sectors() where sectors, not bytes are wantedMarkus Armbruster1-2/+1
Instead of bdrv_getlength(). Aside: a few of these callers don't handle errors. I didn't investigate whether they should. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Use bdrv_nb_sectors() in bdrv_co_get_block_status()Markus Armbruster1-8/+8
Instead of bdrv_getlength(). Replace variables length, length2 by total_sectors, nb_sectors2. Bonus: use total_sectors instead of the slightly unclean bs->total_sectors. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Use bdrv_nb_sectors() in bdrv_aligned_preadv()Markus Armbruster1-5/+4
Instead of bdrv_getlength(). Eliminate variable len. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: Use bdrv_nb_sectors() in bdrv_make_zero()Markus Armbruster1-7/+5
Instead of bdrv_getlength(). Variable target_size is initially in bytes, then changes meaning to sectors. Ugh. Replace by target_sectors. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15block: New bdrv_nb_sectors()Markus Armbruster1-10/+19
A call to retrieve the image size converts between bytes and sectors several times: * BlockDriver method bdrv_getlength() returns bytes. * refresh_total_sectors() converts to sectors, rounding up, and stores in total_sectors. * bdrv_getlength() converts total_sectors back to bytes (now rounded up to a multiple of the sector size). * Callers wanting sectors rather bytes convert it right back. Example: bdrv_get_geometry(). bdrv_nb_sectors() provides a way to omit the last two conversions. It's exactly bdrv_getlength() with the conversion to bytes omitted. It's functionally like bdrv_get_geometry() without its odd error handling. Reimplement bdrv_getlength() and bdrv_get_geometry() on top of bdrv_nb_sectors(). The next patches will convert some users of bdrv_getlength() to bdrv_nb_sectors(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-18block: Add Error argument to bdrv_refresh_limits()Kevin Wolf1-10/+23
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-14block: Assert qiov length matches request lengthKevin Wolf1-0/+2
At least raw-posix relies on this because it can allocate bounce buffers based on the request length, but access it using all of the qiov entries later. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-07-14block: Make qiov match the request size until EOFKevin Wolf1-2/+14
If a read request goes across EOF, the block driver sees a shortened request that stops at EOF (the rest is memsetted in block.c), however the original qiov was used for this request. This patch makes the qiov size match the request size, avoiding a potential buffer overflow in raw-posix. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2014-07-09block: prefer aio_poll to qemu_aio_waitPaolo Bonzini1-1/+1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-07-09block: Fix bdrv_is_allocated() return valueKevin Wolf1-1/+1
bdrv_is_allocated() should return either 0 or 1 in successful cases. We're lucky that currently, the callers that rely on this (e.g. because they check for ret == 1) don't seem to break badly. They just might skip some optimisation or in the case of qemu-io 'map' print separate lines where a single line would suffice. In theory, a wrong allocation status could lead to image corruption with certain operations, so let's fix this quickly. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-07-07block: block: introduce APIs for submitting IO as a batchMing Lei1-0/+31
This patch introduces three APIs so that following patches can support queuing I/O requests and submitting them as a batch for improving I/O performance. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: extend block-commit to accept a string for the backing fileJeff Cody1-2/+6
On some image chains, QEMU may not always be able to resolve the filenames properly, when updating the backing file of an image after a block commit. For instance, certain relative pathnames may fail, or drives may have been specified originally by file descriptor (e.g. /dev/fd/???), or a relative protocol pathname may have been used. In these instances, QEMU may lack the information to be able to make the correct choice, but the user or management layer most likely does have that knowledge. With this extension to the block-commit api, the user is able to change the backing file of the overlay image as part of the block-commit operation. This allows the change to be 'safe', in the sense that if the attempt to write the overlay image metadata fails, then the block-commit operation returns failure, without disrupting the guest. If the commit top is the active layer, then specifying the backing file string will be treated as an error (there is no overlay image to modify in that case). If a backing file string is not specified in the command, the backing file string to use is determined in the same manner as it was previously. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: add helper function to determine if a BDS is in a chainJeff Cody1-0/+11
This is a small helper function, to determine if 'base' is in the chain of BlockDriverState 'top'. It returns true if it is in the chain, and false otherwise. If either argument is NULL, it will also return false. Reviewed-by: Benoit Canet <benoit@irqsave.net> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: simplify bdrv_find_base() and bdrv_find_overlay()Jeff Cody1-35/+10
This simplifies the function bdrv_find_overlay(). With this change, bdrv_find_base() is just a subset of usage of bdrv_find_overlay(), so this also takes advantage of that. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-27block.c: Don't return success for bdrv_append_temp_snapshot() failureChen Gang1-3/+4
When failure occurs, 'ret' need be set, or may return 0 to indicate success. Previously, an error was set in errp, but 0 was returned anyway. So let bdrv_append_temp_snapshot() return an error code and use that for the bdrv_open() return value. Also, error_propagate() need be called only one time within a function. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-27block: Add replaces argument to drive-mirrorBenoît Canet1-0/+25
drive-mirror will bdrv_swap the new BDS named node-name with the one pointed by replaces when the mirroring is finished. Signed-off-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-27block: check for RESIZE blocker in the QMP command, not bdrv_truncate()Jeff Cody1-3/+1
If we check for the RESIZE blocker in bdrv_truncate(), that means a commit will fail if the overlay layer is larger than the base, due to the backing blocker. This is a regression in behavior from 2.0; currently, commit will try to grow the size of the base image to match the overlay size, if the overlay size is larger. By moving this into the QMP command qmp_block_resize(), it allows usage of bdrv_truncate() within block jobs. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-26block: Remove a special case for protocolsKevin Wolf1-16/+2
The only semantic change is that bs->open_flags gets BDRV_O_PROTOCOL set now. This isn't useful, but it doesn't hurt either. The code that was previously skipped by 'goto done' is automatically disabled because protocol drivers don't support backing files (and if they did, this would probably be a fix) and can't have snapshot_flags set. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Catch backing files assigned to non-COW driversKevin Wolf1-0/+7
Since we parse backing.* options to add a backing file from the command line when the driver didn't assign one, it has been possible to have a backing file for e.g. raw images (it just was never accessed). This is obvious nonsense and should be rejected. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Remove second bdrv_open() recursionKevin Wolf1-25/+25
This recursion was introduced in commit 505d7583 in order to allow nesting image formats. It only ever takes effect when the user explicitly specifies a driver name and that driver isn't suitable for the protocol level. We can check this earlier in bdrv_open() and if the explicitly requested driver is a format driver, clear BDRV_O_PROTOCOL so that another bs->file layer is opened. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Inline bdrv_file_open()Kevin Wolf1-40/+11
It doesn't do much any more, we can move the code to bdrv_open() now. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Use common driver selection code for bdrv_open_file()Kevin Wolf1-37/+30
This moves the bdrv_open_file() call a bit down so that it can use the bdrv_open() code that selects the right block driver. The code between the old and the new call site is either common code (the error message for an unknown driver has been unified now) or doesn't run with cleared BDRV_O_PROTOCOL (added an if block in one place, whereas the right path was already asserted in another place) Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-06-26block: Always pass driver name through options QDictKevin Wolf1-36/+40
The "driver" entry in the options QDict is now only missing if we're opening an image with format probing. We also catch cases now where both the drv argument and a "driver" option is specified, e.g. by specifying -drive format=qcow2,driver=raw Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Move json: parsing to bdrv_fill_options()Kevin Wolf1-43/+45
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Move bdrv_fill_options() call to bdrv_open()Kevin Wolf1-10/+15
bs->options now contains the modified version of the options. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-26block: Create bdrv_fill_options()Kevin Wolf1-43/+69
The idea of bdrv_fill_options() is to convert every parameter for opening images, in particular the filename and flags, to entries in the options QDict. This patch starts with moving the filename parsing and driver probing part from bdrv_file_open() to the new function. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2014-06-24block.c: Remove useless 'buf' variableChen Gang1-2/+0
'buf' is not used actually, so remove it and related snprintf() statement. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-06-23qapi event: convert BLOCK_IO_ERROR and BLOCK_JOB_ERRORWenchao Xia1-33/+8
Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23qapi event: convert DEVICE_TRAY_MOVEDWenchao Xia1-14/+7
Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23qapi: adjust existing definesWenchao Xia1-8/+9
In order to let event defines use existing types later, instead of redefine new ones, some old type defines for spice and vnc are changed, and BlockErrorAction is moved from block.h to qapi schema. Note that BlockErrorAction is not merged with BlockdevOnError. At this point, VncInfo is not made a child of VncBasicInfo, because VncBasicInfo has mandatory fields where VncInfo makes them optional. Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-06-23block: asynchronously stop the VM on I/O errorsPaolo Bonzini1-2/+19
With virtio-blk dataplane, I/O errors might occur while QEMU is not in the main I/O thread. However, it's invalid to call vm_stop when we're neither in a VCPU thread nor in the main I/O thread, even if we were to take the iothread mutex around it. To avoid this problem, we can raise a request to the main I/O thread, similar to what QEMU does when vm_stop is called from a CPU thread. We know that bdrv_error_action is called from an AIO callback, and the moment at which the callback will fire is not well-defined; it depends on the moment at which the disk or OS finishes the operation, which can happen at any time. Note that QEMU is certainly not in a CPU thread and we do not need to call cpu_stop_current() like vm_stop() does. However, we need to ensure that any action taken by management will result in correct detection of the error _and_ a running VM. In particular: - the event must be raised after the iostatus has been set, so that "info block" will return an iostatus that matches the event. - the VM must be stopped after the iostatus has been set, so that "info block" will return an iostatus that matches the runstate. The ordering between the STOP and BLOCK_IO_ERROR events is preserved; BLOCK_IO_ERROR is documented to come first. This makes bdrv_error_action() thread safe (assuming QMP events are, which is attacked by a separate series). Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-16cleanup QEMUOptionParameterChunyan Liu1-80/+13
Now that all backend drivers are using QemuOpts, remove all QEMUOptionParameter related codes. Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Chunyan Liu <cyliu@suse.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-16change block layer to support both QemuOpts and QEMUOptionParamterChunyan Liu1-49/+111
Change block layer to support both QemuOpts and QEMUOptionParameter. After this patch, it will change backend drivers one by one. At the end, QEMUOptionParameter will be removed and only QemuOpts is kept. Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com> Signed-off-by: Chunyan Liu <cyliu@suse.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-04throttle: add throttle_detach/attach_aio_context()Stefan Hajnoczi1-0/+7
Block I/O throttling uses timers and currently always adds them to the main loop. Throttling will break if bdrv_set_aio_context() is used to move a BlockDriverState to a different AioContext. This patch adds throttle_detach/attach_aio_context() interfaces so the throttling timers and uses them to move timers to the new AioContext. Note that bdrv_set_aio_context() already drains all requests so we're sure no throttled requests are pending. The test cases need to be updated since the throttle_init() interface has changed. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
2014-06-04block: add bdrv_set_aio_context()Stefan Hajnoczi1-2/+55
Up until now all BlockDriverState instances have used the QEMU main loop for fd handlers, timers, and BHs. This is not scalable on SMP guests and hosts so we need to move to a model with multiple event loops on different host CPUs. bdrv_set_aio_context() assigns the AioContext event loop to use for a particular BlockDriverState. It first detaches the entire BlockDriverState graph from the current AioContext and then attaches to the new AioContext. This function will be used by virtio-blk data-plane to assign a BlockDriverState to its IOThread AioContext. Make bdrv_aio_set_context() public since data-plane should not include block_int.h. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-04block: acquire AioContext in bdrv_drain_all()Stefan Hajnoczi1-14/+11
Modify bdrv_drain_all() to take into account that BlockDriverState instances may be running in different AioContexts. This patch changes the implementation of bdrv_drain_all() while preserving the semantics. Previously kicking throttled requests and checking for pending requests were done across all BlockDriverState instances in sequence. Now we process each BlockDriverState in turn, making sure to acquire and release its AioContext. This prevents race conditions between the thread executing bdrv_drain_all() and the thread running the AioContext. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-04block: acquire AioContext in bdrv_*_all()Stefan Hajnoczi1-1/+23
bdrv_close_all(), bdrv_commit_all(), bdrv_flush_all(), bdrv_invalidate_cache_all(), and bdrv_clear_incoming_migration_all() are called by main loop code and touch all BlockDriverState instances. Some BlockDriverState instances may be running in another AioContext. Make sure to acquire the AioContext before closing the BlockDriverState. This will protect against race conditions once virtio-blk data-plane is using the BlockDriverState from another AioContext event loop. Note that this patch does not convert bdrv_drain_all() yet since that conversion is non-trivial. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-04block: use BlockDriverState AioContextStefan Hajnoczi1-9/+18
Drop the assumption that we're using the main AioContext. Convert qemu_aio_wait() to aio_poll() and qemu_bh_new() to aio_bh_new() so the BlockDriverState AioContext is used. Note there is still one qemu_aio_wait() left in bdrv_create() but we do not have a BlockDriverState there and only main loop code invokes this function. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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