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2023-06-28block: mark another function as coroutine_fns and GRAPH_UNLOCKEDPaolo Bonzini
Mark functions as coroutine_fn when they are only called by other coroutine_fns and they can suspend. Because this function operates on a BlockBackend, mark it GRAPH_UNLOCKED. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20230601115145.196465-6-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28graph-lock: Unlock the AioContext while pollingKevin Wolf
If the caller keeps the AioContext lock for a block node in an iothread, polling in bdrv_graph_wrlock() deadlocks if the condition isn't fulfilled immediately. Now that all callers make sure to actually have the AioContext locked when they call bdrv_replace_child_noperm() like they should, we can change bdrv_graph_wrlock() to take a BlockDriverState whose AioContext lock the caller holds (NULL if it doesn't) and unlock it temporarily while polling. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-11-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28block: Fix AioContext locking in bdrv_open_backing_file()Kevin Wolf
bdrv_set_backing() requires the caller to hold the AioContext lock for @backing_hd. Take it in bdrv_open_backing_file() before calling the function. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-9-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28block: Fix AioContext locking in bdrv_open_inherit()Kevin Wolf
bdrv_open_inherit() calls several functions for which it needs to hold the AioContext lock, but currently doesn't. This includes calls in bdrv_append_temp_snapshot(), for which bdrv_open_inherit() is the only caller. Fix the locking in these places. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-8-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28block: Fix AioContext locking in bdrv_reopen_parse_file_or_backing()Kevin Wolf
bdrv_set_file_or_backing_noperm() requires the caller to hold the AioContext lock for the child node, but we hold the one for the parent node in bdrv_reopen_parse_file_or_backing(). Take the other one temporarily. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-7-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28block: Fix AioContext locking in bdrv_attach_child_common()Kevin Wolf
The function can move the child node to a different AioContext. In this case, it also must take the AioContext lock for the new context before calling functions that require the caller to hold the AioContext for the child node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-6-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-28block: Fix AioContext locking in bdrv_open_child()Kevin Wolf
bdrv_attach_child() requires that the caller holds the AioContext lock for the new child node. Take it in bdrv_open_child() and document that the caller must not hold any AioContext apart from the main AioContext. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-ID: <20230605085711.21261-5-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-06-09block.c: add newline for "Detected format" warningMichael Tokarev
Add the forgotten trailing newline. Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-05-30aio: remove aio_disable_external() APIStefan Hajnoczi
All callers now pass is_external=false to aio_set_fd_handler() and aio_set_event_notifier(). The aio_disable_external() API that temporarily disables fd handlers that were registered is_external=true is therefore dead code. Remove aio_disable_external(), aio_enable_external(), and the is_external arguments to aio_set_fd_handler() and aio_set_event_notifier(). The entire test-fdmon-epoll test is removed because its sole purpose was testing aio_disable_external(). Parts of this patch were generated using the following coccinelle (https://coccinelle.lip6.fr/) semantic patch: @@ expression ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque; @@ - aio_set_fd_handler(ctx, fd, is_external, io_read, io_write, io_poll, io_poll_ready, opaque) + aio_set_fd_handler(ctx, fd, io_read, io_write, io_poll, io_poll_ready, opaque) @@ expression ctx, notifier, is_external, io_read, io_poll, io_poll_ready; @@ - aio_set_event_notifier(ctx, notifier, is_external, io_read, io_poll, io_poll_ready) + aio_set_event_notifier(ctx, notifier, io_read, io_poll, io_poll_ready) Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230516190238.8401-21-stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30block: Fix AioContext locking in bdrv_insert_node()Kevin Wolf
While calling bdrv_new_open_driver_opts(), the main AioContext lock must be held, not the lock of the AioContext of the block subtree it will be added to afterwards. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-11-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30block: Take AioContext lock in bdrv_open_driver()Kevin Wolf
bdrv_refresh_total_sectors() and bdrv_refresh_limits() expect to be called under the AioContext lock of the node. Take the lock. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-10-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30qcow2: Fix open with 'file' in iothreadKevin Wolf
qcow2_open() doesn't work correctly when opening the 'file' child moves bs to an iothread, for several reasons: - It uses BDRV_POLL_WHILE() to wait for the qcow2_open_entry() coroutine, which involves dropping the AioContext lock for bs when it is not in the main context - but we don't hold it, so this crashes. - It runs the qcow2_open_entry() coroutine in the current thread instead of the new AioContext of bs. - qcow2_open_entry() doesn't notify the main loop when it's done. This patches fixes these issues around delegating work to a coroutine. Temporarily dropping the main AioContext lock is not necessary because we know we run in the main thread. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-7-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30mirror: Hold main AioContext lock for calling bdrv_open_backing_file()Kevin Wolf
bdrv_open_backing_file() calls bdrv_open_inherit(), so all callers must hold the main AioContext lock. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-6-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30block: Take main AioContext lock when calling bdrv_open()Kevin Wolf
The function documentation already says that all callers must hold the main AioContext lock, but not all of them do. This can cause assertion failures when functions called by bdrv_open() try to drop the lock. Fix a few more callers to take the lock before calling bdrv_open(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-4-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-30block: Clarify locking rules for bdrv_open(_inherit)()Kevin Wolf
These functions specify that the caller must hold the "@filename AioContext lock". This doesn't make sense, file names don't have an AioContext. New BlockDriverStates always start in the main AioContext, so this is what we really need here. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230525124713.401149-3-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-19block: Call .bdrv_co_create(_opts) unlockedKevin Wolf
These are functions that modify the graph, so they must be able to take a writer lock. This is impossible if they already hold the reader lock. If they need a reader lock for some of their operations, they should take it internally. Many of them go through blk_*(), which will always take the lock itself. Direct calls of bdrv_*() need to take the reader lock. Note that while locking for bdrv_co_*() calls is checked by TSA, this is not the case for the mixed_coroutine_fns bdrv_*(). Holding the lock is still required when they are called from coroutine context like here! This effectively reverts 4ec8df0183, but adds some internal locking instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230510203601.418015-2-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-15block: add zoned BlockDriver check to block layerSam Li
Putting zoned/non-zoned BlockDrivers on top of each other is not allowed. Signed-off-by: Sam Li <faithilikerun@gmail.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com> Acked-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20230508045533.175575-6-faithilikerun@gmail.com Message-id: 20230324090605.28361-6-faithilikerun@gmail.com [Adjust commit message prefix as suggested by Philippe Mathieu-Daudé <philmd@linaro.org> and clarify that the check is about zoned BlockDrivers. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-05-10block: Mark bdrv_refresh_limits() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_refresh_limits() need to hold a reader lock for the graph because it accesses the children list of a node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-21-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: Mark bdrv_co_debug_event() GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_debug_event() need to hold a reader lock for the graph. Unfortunately we cannot use a co_wrapper_bdrv_rdlock (i.e. make the coroutine wrapper a no_coroutine_fn), because the function is called (using the BLKDBG_EVENT macro) by mixed functions that run both in coroutine and non-coroutine context (for example many of the functions in qcow2-cluster.c and qcow2-refcount.c). Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-16-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: Mark bdrv_co_get_info() and callers GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_get_info() need to hold a reader lock for the graph. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-15-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: Mark bdrv_co_get_allocated_file_size() and callers GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_get_allocated_file_size() need to hold a reader lock for the graph. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20230504115750.54437-14-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: .bdrv_open is non-coroutine and unlockedKevin Wolf
Drivers were a bit confused about whether .bdrv_open can run in a coroutine and whether or not it holds a graph lock. It cannot keep a graph lock from the caller across the whole function because it both changes the graph (requires a writer lock) and does I/O (requires a reader lock). Therefore, it should take these locks internally as needed. The functions used to be called in coroutine context during image creation. This was buggy for other reasons, and as of commit 32192301, all block drivers go through no_co_wrappers. So it is not called in coroutine context any more. Fix qcow2 and qed to work with the correct assumptions: The graph lock needs to be taken internally instead of just assuming it's already there, and the coroutine path is dead code that can be removed. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-9-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-05-10block: bdrv/blk_co_unref() for calls in coroutine contextKevin Wolf
These functions must not be called in coroutine context, because they need write access to the graph. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230504115750.54437-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-25block: add missing coroutine_fn to bdrv_sum_allocated_file_size()Stefan Hajnoczi
Not a coroutine_fn, you say? static int64_t bdrv_sum_allocated_file_size(BlockDriverState *bs) { BdrvChild *child; int64_t child_size, sum = 0; QLIST_FOREACH(child, &bs->children, next) { if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA | BDRV_CHILD_FILTERED)) { child_size = bdrv_co_get_allocated_file_size(child->bs); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Well what do we have here?! I rest my case, your honor. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20230308211435.346375-1-stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-11block, block-backend: write some hot coroutine wrappers by handPaolo Bonzini
The introduction of the graph lock is causing blk_get_geometry, a hot function used in the I/O path, to create a coroutine. However, the only part that really needs to run in coroutine context is the call to bdrv_co_refresh_total_sectors, which in turn only happens in the rare case of host CD-ROM devices. So, write by hand the three wrappers on the path from blk_co_get_geometry to bdrv_co_refresh_total_sectors, so that the coroutine wrapper is only created if bdrv_nb_sectors actually calls bdrv_refresh_total_sectors. Reported-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20230407153303.391121-9-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-11block-backend: inline bdrv_co_get_geometryPaolo Bonzini
bdrv_co_get_geometry is only used in blk_co_get_geometry. Inline it in there, to reduce the number of wrappers for bs->total_sectors. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20230407153303.391121-7-pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-11block: refresh bs->total_sectors on reopenPaolo Bonzini
After reopening a BlockDriverState, it's possible that the size of the underlying file has changed. This for example is covered by test 171. Right now, this is handled by the raw driver's has_variable_length = true setting. Since this will be removed by the next patch, handle it on reopen instead, together with the existing bdrv_refresh_limits. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20230407153303.391121-4-pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-04-11block: move has_variable_length to BlockLimitsPaolo Bonzini
At the protocol level, has_variable_length only needs to be true in the very special case of host CD-ROM drives, so that they do not need an explicit monitor command to read the new size when a disc is loaded in the tray. However, at the format level has_variable_length has to be true for all raw blockdevs and for all filters, even though in practice the length depends on the underlying file and thus will not change except in the case of host CD-ROM drives. As a first step towards computing an accurate value of has_variable_length, add the value into the BlockLimits structure and initialize the field from the BlockDriver. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20230407153303.391121-2-pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-03-27block/export: Fix graph locking in blk_get_geometry() callKevin Wolf
blk_get_geometry() eventually calls bdrv_nb_sectors(), which is a co_wrapper_mixed_bdrv_rdlock. This means that when it is called from coroutine context, it already assume to have the graph locked. However, virtio_blk_sect_range_ok() in block/export/virtio-blk-handler.c (used by vhost-user-blk and VDUSE exports) runs in a coroutine, but doesn't take the graph lock - blk_*() functions are generally expected to do that internally. This causes an assertion failure when accessing an export for the first time if it runs in an iothread. This is an example of the crash: $ ./storage-daemon/qemu-storage-daemon --object iothread,id=th0 --blockdev file,filename=/home/kwolf/images/hd.img,node-name=disk --export vhost-user-blk,addr.type=unix,addr.path=/tmp/vhost.sock,node-name=disk,id=exp0,iothread=th0 qemu-storage-daemon: ../block/graph-lock.c:268: void assert_bdrv_graph_readable(void): Assertion `qemu_in_main_thread() || reader_count()' failed. (gdb) bt #0 0x00007ffff6eafe5c in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x00007ffff6e5fa76 in raise () from /lib64/libc.so.6 #2 0x00007ffff6e497fc in abort () from /lib64/libc.so.6 #3 0x00007ffff6e4971b in __assert_fail_base.cold () from /lib64/libc.so.6 #4 0x00007ffff6e58656 in __assert_fail () from /lib64/libc.so.6 #5 0x00005555556337a3 in assert_bdrv_graph_readable () at ../block/graph-lock.c:268 #6 0x00005555555fd5a2 in bdrv_co_nb_sectors (bs=0x5555564c5ef0) at ../block.c:5847 #7 0x00005555555ee949 in bdrv_nb_sectors (bs=0x5555564c5ef0) at block/block-gen.c:256 #8 0x00005555555fd6b9 in bdrv_get_geometry (bs=0x5555564c5ef0, nb_sectors_ptr=0x7fffef7fedd0) at ../block.c:5884 #9 0x000055555562ad6d in blk_get_geometry (blk=0x5555564cb200, nb_sectors_ptr=0x7fffef7fedd0) at ../block/block-backend.c:1624 #10 0x00005555555ddb74 in virtio_blk_sect_range_ok (blk=0x5555564cb200, block_size=512, sector=0, size=512) at ../block/export/virtio-blk-handler.c:44 #11 0x00005555555dd80d in virtio_blk_process_req (handler=0x5555564cbb98, in_iov=0x7fffe8003830, out_iov=0x7fffe8003860, in_num=1, out_num=0) at ../block/export/virtio-blk-handler.c:189 #12 0x00005555555dd546 in vu_blk_virtio_process_req (opaque=0x7fffe8003800) at ../block/export/vhost-user-blk-server.c:66 #13 0x00005555557bf4a1 in coroutine_trampoline (i0=-402635264, i1=32767) at ../util/coroutine-ucontext.c:177 #14 0x00007ffff6e75c20 in ?? () from /lib64/libc.so.6 #15 0x00007fffefffa870 in ?? () #16 0x0000000000000000 in ?? () Fix this by creating a new blk_co_get_geometry() that takes the lock, and changing blk_get_geometry() to be a co_wrapper_mixed around it. To make the resulting code cleaner, virtio-blk-handler.c can directly call the coroutine version now (though that wouldn't be necessary for fixing the bug, taking the lock in blk_co_get_geometry() is what fixes it). Fixes: 8ab8140a04cf771d63e9754d6ba6c1e676bfe507 Reported-by: Lukáš Doktor <ldoktor@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230327113959.60071-1-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_refresh_total_sectors() need to hold a reader lock for the graph. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-24-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_delete_file() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_delete_file() need to hold a reader lock for the graph. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-22-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_eject/lock_medium() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_eject() and bdrv_co_lock_medium() need to hold a reader lock for the graph. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-20-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_is_inserted() and callers GRAPH_RDLOCKEmanuele Giuseppe Esposito
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_is_inserted() need to hold a reader lock for the graph. blk_is_inserted() is done as a co_wrapper_mixed_bdrv_rdlock (unlike most other blk_* functions) because it is called a lot from other blk_co_*() functions that already hold the lock. These calls go through blk_is_available(), which becomes a co_wrapper_mixed_bdrv_rdlock, too, for the same reason. Functions that run in a coroutine and can call bdrv_co_is_available() directly are changed to do so, which results in better TSA coverage. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-19-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Mark bdrv_co_create() and callers GRAPH_RDLOCKKevin Wolf
This adds GRAPH_RDLOCK annotations to declare that callers of bdrv_co_create() need to hold a reader lock for the graph. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-17-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-23block: Make bdrv_can_set_read_only() staticKevin Wolf
It is never called outside of block.c. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230203152202.49054-2-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17block: temporarily hold the new AioContext of bs_top in bdrv_append()Stefano Garzarella
bdrv_append() is called with bs_top AioContext held, but bdrv_attach_child_noperm() could change the AioContext of bs_top. bdrv_replace_node_noperm() calls bdrv_drained_begin() starting from commit 2398747128 ("block: Don't poll in bdrv_replace_child_noperm()"). bdrv_drained_begin() can call BDRV_POLL_WHILE that assumes the new lock is taken, so let's temporarily hold the new AioContext to prevent QEMU from failing in BDRV_POLL_WHILE when it tries to release the wrong AioContext. Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2168209 Reported-by: Aihua Liang <aliang@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20230214171621.11574-1-sgarzare@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17block: Assert non-coroutine context for bdrv_open_inherit()Kevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230126172432.436111-14-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-17block: Fix bdrv_co_create_opts_simple() to open images with no_co_wrapperKevin Wolf
bdrv_co_create_opts_simple() runs in a coroutine. Therefore it is not allowed to open images directly. Fix the call to use the corresponding no_co_wrapper instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230126172432.436111-13-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Hanna Czenczek <hreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_debug_event() to co_wrapper_mixedEmanuele Giuseppe Esposito
bdrv_debug_event() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper_mixed to move the actual function into a coroutine where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-14-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_lock_medium() to co_wrapperEmanuele Giuseppe Esposito
bdrv_lock_medium() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. The only caller of this function is blk_lock_medium(). Therefore make blk_lock_medium() a co_wrapper, so that it always creates a new coroutine, and then make bdrv_lock_medium() a coroutine_fn where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-13-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_eject() to co_wrapperEmanuele Giuseppe Esposito
bdrv_eject() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. The only caller of this function is blk_eject(). Therefore make blk_eject() a co_wrapper, so that it always creates a new coroutine, and then make bdrv_eject() coroutine_fn where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-12-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_get_info() to co_wrapper_mixedEmanuele Giuseppe Esposito
bdrv_get_info() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper to move the actual function into a coroutine where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-11-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_get_allocated_file_size() to co_wrapperEmanuele Giuseppe Esposito
bdrv_get_allocated_file_size() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper to move the actual function into a coroutine where the lock can be taken. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-10-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixedEmanuele Giuseppe Esposito
BlockDriver->bdrv_getlength is categorized as IO callback, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since the callback traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper to move the actual function into a coroutine where the lock can be taken. Because now this function creates a new coroutine and polls, we need to take the AioContext lock where it is missing, for the only reason that internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the AioContext lock. This is especially messy when a co_wrapper creates a coroutine and polls in bdrv_open_driver, because this function has so many callers in so many context that it can easily lead to deadlocks. Therefore the new rule for bdrv_open_driver is that the caller must always hold the AioContext lock of the given bs (except if it is a coroutine), because the function calls bdrv_refresh_total_sectors() which is now a co_wrapper. Once the rwlock is ultimated and placed in every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext lock. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-7-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Rename refresh_total_sectors to bdrv_refresh_total_sectorsEmanuele Giuseppe Esposito
The name is not good, not the least because we are going to convert this to a generated co_wrapper, which adds a _co infix after the first part of the name. No functional change intended. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-6-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-02-01block: Convert bdrv_is_inserted() to co_wrapperEmanuele Giuseppe Esposito
bdrv_is_inserted() is categorized as an I/O function, and it currently doesn't run in a coroutine. We should let it take a graph rdlock since it traverses the block nodes graph, which however is only possible in a coroutine. Therefore turn it into a co_wrapper to move the actual function into a coroutine where the lock can be taken. At the same time, add also blk_is_inserted as co_wrapper_mixed, since it is called in both coroutine and non-coroutine contexts. Because now this function creates a new coroutine and polls, we need to take the AioContext lock where it is missing, for the only reason that internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to release the AioContext lock. Once the rwlock is ultimated and placed in every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext lock. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20230113204212.359076-5-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-01-24block: remove bdrv_coroutine_enterPaolo Bonzini
It has only one caller---inline it and remove the function. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20221215130225.476477-2-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-01-20include/block: Untangle inclusion loopsMarkus Armbruster
We have two inclusion loops: block/block.h -> block/block-global-state.h -> block/block-common.h -> block/blockjob.h -> block/block.h block/block.h -> block/block-io.h -> block/block-common.h -> block/blockjob.h -> block/block.h I believe these go back to Emanuele's reorganization of the block API, merged a few months ago in commit d7e2fe4aac8. Fortunately, breaking them is merely a matter of deleting unnecessary includes from headers, and adding them back in places where they are now missing. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2022-12-15block: GRAPH_RDLOCK for functions only called by co_wrappersKevin Wolf
The generated coroutine wrappers already take care to take the lock in the non-coroutine path, and assume that the lock is already taken in the coroutine path. The only thing we need to do for the wrapped function is adding the GRAPH_RDLOCK annotation. Doing so also allows us to mark the corresponding callbacks in BlockDriver as GRAPH_RDLOCK_PTR. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-19-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-12-15Mark assert_bdrv_graph_readable/writable() GRAPH_RD/WRLOCKKevin Wolf
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20221207131838.239125-16-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>