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2021-09-15block: bdrv_inactivate_recurse(): check for permissions and fix crashVladimir Sementsov-Ogievskiy1-0/+8
We must not inactivate child when parent has write permissions on it. Calling .bdrv_inactivate() doesn't help: actually only qcow2 has this handler and it is used to flush caches, not for permission manipulations. So, let's simply check cumulative parent permissions before inactivating the node. This commit fixes a crash when we do migration during backup: prior to the commit nothing prevents all nodes inactivation at migration finish and following backup write to the target crashes on assertion "assert(!(bs->open_flags & BDRV_O_INACTIVE));" in bdrv_co_write_req_prepare(). After the commit, we rely on the fact that copy-before-write filter keeps write permission on target node to be able to write to it. So inactivation fails and migration fails as expected. Corresponding test now passes, so, enable it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210911120027.8063-3-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-15block: block-status cache for data regionsHanna Reitz1-0/+80
As we have attempted before (https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg06451.html, "file-posix: Cache lseek result for data regions"; https://lists.nongnu.org/archive/html/qemu-block/2021-02/msg00934.html, "file-posix: Cache next hole"), this patch seeks to reduce the number of SEEK_DATA/HOLE operations the file-posix driver has to perform. The main difference is that this time it is implemented as part of the general block layer code. The problem we face is that on some filesystems or in some circumstances, SEEK_DATA/HOLE is unreasonably slow. Given the implementation is outside of qemu, there is little we can do about its performance. We have already introduced the want_zero parameter to bdrv_co_block_status() to reduce the number of SEEK_DATA/HOLE calls unless we really want zero information; but sometimes we do want that information, because for files that consist largely of zero areas, special-casing those areas can give large performance boosts. So the real problem is with files that consist largely of data, so that inquiring the block status does not gain us much performance, but where such an inquiry itself takes a lot of time. To address this, we want to cache data regions. Most of the time, when bad performance is reported, it is in places where the image is iterated over from start to end (qemu-img convert or the mirror job), so a simple yet effective solution is to cache only the current data region. (Note that only caching data regions but not zero regions means that returning false information from the cache is not catastrophic: Treating zeroes as data is fine. While we try to invalidate the cache on zero writes and discards, such incongruences may still occur when there are other processes writing to the image.) We only use the cache for nodes without children (i.e. protocol nodes), because that is where the problem is: Drivers that rely on block-status implementations outside of qemu (e.g. SEEK_DATA/HOLE). Resolves: https://gitlab.com/qemu-project/qemu/-/issues/307 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Message-Id: <20210812084148.14458-3-hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> [hreitz: Added `local_file == bs` assertion, as suggested by Vladimir] Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-09-01block: introduce bdrv_replace_child_bs()Vladimir Sementsov-Ogievskiy1-0/+31
Add function to transactionally replace bs inside BdrvChild. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-2-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-07-20block: Add option to use driver whitelist even in toolsKevin Wolf1-0/+3
Currently, the block driver whitelists are only applied for the system emulator. All other binaries still give unrestricted access to all block drivers. There are use cases where this made sense because the main concern was avoiding customers running VMs on less optimised block drivers and getting bad performance. Allowing the same image format e.g. as a target for 'qemu-img convert' is not a problem then. However, if the concern is the supportability of the driver in general, either in full or when used read-write, not applying the list driver whitelist in tools doesn't help - especially since qemu-nbd and qemu-storage-daemon now give access to more or less the same operations in block drivers as running a system emulator. In order to address this, introduce a new configure option that enforces the driver whitelist in all binaries. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210709164141.254097-1-kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09block: Acquire AioContexts during bdrv_reopen_multiple()Kevin Wolf1-7/+42
As the BlockReopenQueue can contain nodes in multiple AioContexts, only one of which may be locked when AIO_WAIT_WHILE() can be called, we can't let the caller lock the right contexts. Instead, individually lock the AioContext of a single node when iterating the queue. Reintroduce bdrv_reopen() as a wrapper for reopening a single node that drains the node and temporarily drops the AioContext lock for bdrv_reopen_multiple(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210708114709.206487-4-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09block: Add bdrv_reopen_queue_free()Alberto Garcia1-6/+16
Move the code to free a BlockReopenQueue to a separate function. It will be used in a subsequent patch. [ kwolf: Also free explicit_options and options, and explicitly qobject_ref() the value when it continues to be used. This makes future memory leaks less likely. ] Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210708114709.206487-3-kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-07-09qemu-img: Require -F with -b backing imageEric Blake1-26/+11
Back in commit d9f059aa6c (qemu-img: Deprecate use of -b without -F), we deprecated the ability to create a file with a backing image that requires qemu to perform format probing. Qemu can still probe older files for backwards compatibility, but it is time to finish off the ability to create such images, due to the potential security risk they present. Update a couple of iotests affected by the change. Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20210503213600.569128-3-eblake@redhat.com> Reviewed-by: Connor Kuehl <ckuehl@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: Allow changing bs->file on reopenAlberto Garcia1-24/+54
When the x-blockdev-reopen was added it allowed reconfiguring the graph by replacing backing files, but changing the 'file' option was forbidden. Because of this restriction some operations are not possible, notably inserting and removing block filters. This patch adds support for replacing the 'file' option. This is similar to replacing the backing file and the user is likewise responsible for the correctness of the resulting graph, otherwise this can lead to data corruption. Signed-off-by: Alberto Garcia <berto@igalia.com> [vsementsov: bdrv_reopen_parse_file_or_backing() is modified a lot] Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-9-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: BDRVReopenState: drop replace_backing_bs fieldVladimir Sementsov-Ogievskiy1-6/+4
It's used only in bdrv_reopen_commit(). "backing" is covered by the loop through all children except for case when we removed backing child during reopen. Make it more obvious and drop extra boolean field: qdict_del will not fail if there is no such entry. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-8-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: move supports_backing check to bdrv_set_file_or_backing_noperm()Vladimir Sementsov-Ogievskiy1-14/+15
Move supports_backing check of bdrv_reopen_parse_backing to called (through bdrv_set_backing_noperm()) bdrv_set_file_or_backing_noperm() function. The check applies to general case, so it's appropriate for bdrv_set_file_or_backing_noperm(). We have to declare backing support for two test drivers, otherwise new check fails. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-7-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: bdrv_reopen_parse_backing(): simplify handling implicit filtersVladimir Sementsov-Ogievskiy1-37/+16
The logic around finding overlay here is not obvious. Actually it does two simple things: 1. If new bs is already in backing chain, split from parent bs by several implicit filters we are done, do nothing. 2. Otherwise, don't try to replace implicit filter. Let's rewrite this in more obvious way. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-6-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: bdrv_reopen_parse_backing(): don't check frozen childVladimir Sementsov-Ogievskiy1-13/+1
bdrv_set_backing_noperm() takes care of it (actual check is in bdrv_set_file_or_backing_noperm()), so we don't need to check it here. While being here, improve error message a bit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-5-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: bdrv_reopen_parse_backing(): don't check aio contextVladimir Sementsov-Ogievskiy1-33/+0
We don't need this check: bdrv_set_backing_noperm() will do it anyway (actually in bdrv_attach_child_common()). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-4-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: introduce bdrv_set_file_or_backing_noperm()Vladimir Sementsov-Ogievskiy1-20/+63
To be used for reopen in future commit. Notes: - It seems OK to update inherits_from if new bs is recursively inherits from parent bs. Let's just not check for backing_chain_contains, to support file child of non-filters. - Simply check child->frozen instead of bdrv_is_backing_chain_frozen(), as we really interested only in this one child. - Role determination of new child is a bit more complex: it remains the same for backing child, it's obvious for filter driver. But for non-filter file child let's for now restrict to only replacing existing child (and keeping its role). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-3-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: introduce bdrv_remove_file_or_backing_child()Vladimir Sementsov-Ogievskiy1-7/+17
To be used for reopen in future commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210610120537.196183-2-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: comment graph-modifying function not updating permissionsVladimir Sementsov-Ogievskiy1-0/+8
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210610112618.127378-3-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: rename bdrv_replace_child to bdrv_replace_child_tranVladimir Sementsov-Ogievskiy1-6/+8
We have bdrv_replace_child() wrapper on bdrv_replace_child_noperm(). But bdrv_replace_child() doesn't update permissions. It's rather strange, as normally it's expected that foo() should call foo_noperm() and update permissions. Let's rename and add comment. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210610112618.127378-2-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29block: BDRV_O_NO_IO for backing file on creationMax Reitz1-1/+5
When creating an image file with a backing file, we generally try to open the backing file (unless -u was specified), mostly to verify that it is there, but also to get the file size if none was specified for the new image. For neither of these things do we need data I/O, and so we can pass BDRV_O_NO_IO when opening the backing file. This allows us to open even encrypted backing images without requiring the user to provide a secret. This makes the -u switch in iotests 189 and 198 unnecessary (and the $size parameter), so drop it, because this way we get regression tests for this patch here. Fixes: https://gitlab.com/qemu-project/qemu/-/issues/441 Signed-off-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210622140030.212487-1-mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-29Prevent compiler warning on block.cMiroslav Rezanina1-1/+1
Commit 3108a15cf (block: introduce bdrv_drop_filter()) introduced uninitialized variable to_cow_parent in bdrv_replace_node_common function that is used only when detach_subchain is true. It is used in two places. First if block properly initialize the variable and second block use it. However, compiler may treat these two blocks as two independent cases so it thinks first block can fail test and second one pass (although both use same condition). This cause warning that variable can be uninitialized in second block. The warning was observed with GCC 8.4.1 and 11.0.1. To prevent this warning, initialize the variable with NULL. Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> Message-Id: <1162368493.17178530.1620201543649.JavaMail.zimbra@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-25block: check for sys/disk.hJoelle van Dyne1-1/+1
Some BSD platforms do not have this header. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Joelle van Dyne <j@getutm.app> Message-Id: <20210315180341.31638-3-j@getutm.app> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-02block: improve permission conflict error messageVladimir Sementsov-Ogievskiy1-7/+22
Now permissions are updated as follows: 1. do graph modifications ignoring permissions 2. do permission update (of course, we rollback [1] if [2] fails) So, on stage [2] we can't say which users are "old" and which are "new" and exist only since [1]. And current error message is a bit outdated. Let's improve it, to make everything clean. While being here, add also a comment and some good assertions. iotests 283, 307, qsd-jobs outputs are updated. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210601075218.79249-7-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: simplify bdrv_child_user_desc()Vladimir Sementsov-Ogievskiy1-5/+2
All child classes have this callback. So, drop unreachable code. Still add an assertion to bdrv_attach_child_common(), to early detect bad classes. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210601075218.79249-6-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: improve bdrv_child_get_parent_desc()Vladimir Sementsov-Ogievskiy1-1/+1
We have different types of parents: block nodes, block backends and jobs. So, it makes sense to specify type together with name. Next, this handler us used to compose an error message about permission conflict. And permission conflict occurs in a specific place of block graph. We shouldn't report name of parent device (as it refers another place in block graph), but exactly and only the name of the node. So, use bdrv_get_node_name() directly. iotest 283 output is updated. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-Id: <20210601075218.79249-4-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: document child argument of bdrv_attach_child_common()Vladimir Sementsov-Ogievskiy1-9/+15
The logic around **child is not obvious: this reference is used not only to return resulting child, but also to rollback NULL value on transaction abort. So, let's add documentation and some assertions. While being here, drop extra declaration of bdrv_attach_child_noperm(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210601075218.79249-2-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: drop BlockDriverState::read_onlyVladimir Sementsov-Ogievskiy1-6/+1
This variable is just a cache for !(bs->open_flags & BDRV_O_RDWR), which we have to synchronize everywhere. Let's just drop it and consistently use bdrv_is_read_only(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210527154056.70294-3-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block: consistently use bdrv_is_read_only()Vladimir Sementsov-Ogievskiy1-4/+7
It's better to use accessor function instead of bs->read_only directly. In some places use bdrv_is_writable() instead of checking both BDRV_O_RDWR set and BDRV_O_INACTIVE not set. In bdrv_open_common() it's a bit strange to add one more variable, but we are going to drop bs->read_only in the next patch, so new ro local variable substitutes it here. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210527154056.70294-2-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-06-02block/vvfat: child_vvfat_qcow: add .get_parent_aio_context, fix crashVladimir Sementsov-Ogievskiy1-2/+2
Commit 3ca1f3225727419ba573673b744edac10904276f "block: BdrvChildClass: add .get_parent_aio_context handler" introduced new handler and commit 228ca37e12f97788e05bd0c92f89b3e5e4019607 "block: drop ctx argument from bdrv_root_attach_child" made a generic use of it. But 3ca1f3225727419ba573673b744edac10904276f didn't update child_vvfat_qcow. Fix that. Before that fix the command ./build/qemu-system-x86_64 -usb -device usb-storage,drive=fat16 \ -drive file=fat:rw:fat-type=16:"<path of a host folder>",id=fat16,format=raw,if=none crashes: 1 bdrv_child_get_parent_aio_context (c=0x559d62426d20) at ../block.c:1440 2 bdrv_attach_child_common (child_bs=0x559d62468190, child_name=0x559d606f9e3d "write-target", child_class=0x559d60c58d20 <child_vvfat_qcow>, child_role=3, perm=3, shared_perm=4, opaque=0x559d62445690, child=0x7ffc74c2acc8, tran=0x559d6246ddd0, errp=0x7ffc74c2ae60) at ../block.c:2795 3 bdrv_attach_child_noperm (parent_bs=0x559d62445690, child_bs=0x559d62468190, child_name=0x559d606f9e3d "write-target", child_class=0x559d60c58d20 <child_vvfat_qcow>, child_role=3, child=0x7ffc74c2acc8, tran=0x559d6246ddd0, errp=0x7ffc74c2ae60) at ../block.c:2855 4 bdrv_attach_child (parent_bs=0x559d62445690, child_bs=0x559d62468190, child_name=0x559d606f9e3d "write-target", child_class=0x559d60c58d20 <child_vvfat_qcow>, child_role=3, errp=0x7ffc74c2ae60) at ../block.c:2953 5 bdrv_open_child (filename=0x559d62464b80 "/var/tmp/vl.h3TIS4", options=0x559d6246ec20, bdref_key=0x559d606f9e3d "write-target", parent=0x559d62445690, child_class=0x559d60c58d20 <child_vvfat_qcow>, child_role=3, allow_none=false, errp=0x7ffc74c2ae60) at ../block.c:3351 6 enable_write_target (bs=0x559d62445690, errp=0x7ffc74c2ae60) at ../block/vvfat.c:3176 7 vvfat_open (bs=0x559d62445690, options=0x559d6244adb0, flags=155650, errp=0x7ffc74c2ae60) at ../block/vvfat.c:1236 8 bdrv_open_driver (bs=0x559d62445690, drv=0x559d60d4f7e0 <bdrv_vvfat>, node_name=0x0, options=0x559d6244adb0, open_flags=155650, errp=0x7ffc74c2af70) at ../block.c:1557 9 bdrv_open_common (bs=0x559d62445690, file=0x0, options=0x559d6244adb0, errp=0x7ffc74c2af70) at ... (gdb) fr 1 #1 0x0000559d603ea3bf in bdrv_child_get_parent_aio_context (c=0x559d62426d20) at ../block.c:1440 1440 return c->klass->get_parent_aio_context(c); (gdb) p c->klass $1 = (const BdrvChildClass *) 0x559d60c58d20 <child_vvfat_qcow> (gdb) p c->klass->get_parent_aio_context $2 = (AioContext *(*)(BdrvChild *)) 0x0 Fixes: 3ca1f3225727419ba573673b744edac10904276f Fixes: 228ca37e12f97788e05bd0c92f89b3e5e4019607 Reported-by: John Arbuckle <programmingkidx@gmail.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210524101257.119377-2-vsementsov@virtuozzo.com> Tested-by: John Arbuckle <programmingkidx@gmail.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-05-18block: Fix Transaction leak in bdrv_reopen_multiple()Kevin Wolf1-1/+1
Like other error paths, this one needs to call tran_finalize() and clean up the BlockReopenQueue, too. Fixes: CID 1452772 Fixes: 72373e40fbc7e4218061a8211384db362d3e7348 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210503110555.24001-3-kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-05-18block: Fix Transaction leak in bdrv_root_attach_child()Kevin Wolf1-3/+4
The error path needs to call tran_finalize(), too. Fixes: CID 1452773 Fixes: 548a74c0dbc858edd1a7ee3045b5f2fe710bd8b1 Signed-off-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210503110555.24001-2-kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-05-14block: drop write notifiersVladimir Sementsov-Ogievskiy1-1/+0
They are unused now. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210506090621.11848-3-vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2021-05-02Do not include sysemu/sysemu.h if it's not really necessaryThomas Huth1-1/+0
Stop including sysemu/sysemu.h in files that don't need it. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20210416171314.2074665-2-thuth@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-04-30block: refactor bdrv_node_check_perm()Vladimir Sementsov-Ogievskiy1-27/+11
Now, bdrv_node_check_perm() is called only with fresh cumulative permissions, so its actually "refresh_perm". Move permission calculation to the function. Also, drop unreachable error message and rewrite the remaining one to be more generic (as now we don't know which node is added and which was already here). Add also Virtuozzo copyright, as big work is done at this point. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-37-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: rename bdrv_replace_child_safe() to bdrv_replace_child()Vladimir Sementsov-Ogievskiy1-5/+5
We don't have bdrv_replace_child(), so it's time for bdrv_replace_child_safe() to take its place. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-36-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: refactor bdrv_child_set_perm_safe() transaction actionVladimir Sementsov-Ogievskiy1-41/+22
Old interfaces dropped, nobody directly calls bdrv_child_set_perm_abort() and bdrv_child_set_perm_commit(), so we can use personal state structure for the action and stop exploiting BdrvChild structure. Also, drop "_safe" suffix which is redundant now. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-35-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: inline bdrv_replace_child()Vladimir Sementsov-Ogievskiy1-83/+18
bdrv_replace_child() has only one caller, the second argument is unused. Inline it now. This triggers deletion of some more unused interfaces. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-34-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: inline bdrv_check_perm_common()Vladimir Sementsov-Ogievskiy1-29/+3
bdrv_check_perm_common() has only one caller, so no more sense in "common". Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-33-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: drop unused permission update functionsVladimir Sementsov-Ogievskiy1-103/+0
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-32-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: bdrv_reopen_multiple: refresh permissions on updated graphVladimir Sementsov-Ogievskiy1-133/+54
Move bdrv_reopen_multiple to new paradigm of permission update: first update graph relations, then do refresh the permissions. We have to modify reopen process in file-posix driver: with new scheme we don't have prepared permissions in raw_reopen_prepare(), so we should reconfigure fd in raw_check_perm(). Still this seems more native and simple anyway. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-31-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepareVladimir Sementsov-Ogievskiy1-6/+8
During reopen we may add backing bs from other aio context, which may lead to changing original context of top bs. We are going to move graph modification to prepare stage. So, it will be possible that bdrv_flush() in bdrv_reopen_prepare called on bs in non-original aio context, which we didn't aquire which leads to crash. To avoid this problem move bdrv_flush() to be a separate reopen stage before bdrv_reopen_prepare(). This doesn't seem correct to acquire only one aio context and not all contexts participating in reopen. But it's not obvious how to do it correctly, keeping in mind: 1. rules of bdrv_set_aio_context_ignore() that requires new_context lock not being held 2. possible deadlocks because of holding all (or several?) AioContext locks Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-30-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: add bdrv_set_backing_noperm() transaction actionVladimir Sementsov-Ogievskiy1-17/+37
Split out no-perm part of bdrv_set_backing_hd() as a separate transaction action. Note the in case of existing BdrvChild we reuse it, not recreate, just to do less actions. We don't need to create extra reference to backing_hd as we don't lose it in bdrv_attach_child(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-29-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: make bdrv_refresh_limits() to be a transaction actionVladimir Sementsov-Ogievskiy1-5/+4
To be used in further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-28-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: make bdrv_unset_inherits_from to be a transaction actionVladimir Sementsov-Ogievskiy1-4/+42
To be used in the further commit. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-27-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: drop ignore_children for permission update functionsVladimir Sementsov-Ogievskiy1-27/+11
This argument is always NULL. Drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-26-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: introduce bdrv_drop_filter()Vladimir Sementsov-Ogievskiy1-4/+39
Using bdrv_replace_node() for removing filter is not good enough: it keeps child reference of the filter, which may conflict with original top node during permission update. Instead let's create new interface, which will do all graph modifications first and then update permissions. Let's modify bdrv_replace_node_common(), allowing it additionally drop backing chain child link pointing to new node. This is quite appropriate for bdrv_drop_intermediate() and makes possible to add new bdrv_drop_filter() as a simple wrapper. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-24-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: add bdrv_remove_filter_or_cow transaction actionVladimir Sementsov-Ogievskiy1-2/+82
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-23-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: adapt bdrv_append() for inserting filtersVladimir Sementsov-Ogievskiy1-7/+20
bdrv_append is not very good for inserting filters: it does extra permission update as part of bdrv_set_backing_hd(). During this update filter may conflict with other parents of top_bs. Instead, let's first do all graph modifications and after it update permissions. append-greedy-filter test-case in test-bdrv-graph-mod is now works, so move it out of debug option. Note: bdrv_append() is still only works for backing-child based filters. It's something to improve later. Note2: we use the fact that bdrv_append() is used to append new nodes, without backing child, so we don't need frozen check and inherits_from logic from bdrv_set_backing_hd(). Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-22-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: split out bdrv_replace_node_noperm()Vladimir Sementsov-Ogievskiy1-19/+31
Split part of bdrv_replace_node_common() to be used separately. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-21-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: add bdrv_attach_child_noperm() transaction actionVladimir Sementsov-Ogievskiy1-13/+58
Split no-perm part of bdrv_attach_child as separate transaction action. It will be used in later commits. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-20-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: add bdrv_attach_child_common() transaction actionVladimir Sementsov-Ogievskiy1-54/+136
Split out no-perm part of bdrv_root_attach_child() into separate transaction action. bdrv_root_attach_child() now moves to new permission update paradigm: first update graph relations then update permissions. qsd-jobs test output updated. Seems now permission update goes in another order. Still, the test comment say that we only want to check that command doesn't crash, and it's still so. Error message is a bit misleading as it looks like job was added first. But actually in new paradigm of graph update we can't distinguish such things. We should update the error message, but let's not do it now. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210428151804.439460-19-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-04-30block: fix bdrv_replace_node_commonVladimir Sementsov-Ogievskiy1-25/+18
inore_children thing doesn't help to track all propagated permissions of children we want to ignore. The simplest way to correctly update permissions is update graph first and then do permission update. In this case we just referesh permissions for the whole subgraph (in topological-sort defined order) and everything is correctly calculated automatically without any ignore_children. So, refactor bdrv_replace_node_common to first do graph update and then refresh the permissions. Test test_parallel_exclusive_write() now pass, so move it out of debugging "if". Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20210428151804.439460-18-vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>