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2017-04-24block: use bdrv_can_set_read_only() during reopenJeff Cody1-6/+8
Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 00aed7ffdd7be4b9ed9ce1007d50028a72b34ebe.1491597120.git.jcody@redhat.com
2017-04-24block: introduce bdrv_can_set_read_only()Jeff Cody1-1/+13
Introduce check function for setting read_only flags. Will return < 0 on error, with appropriate Error value set. Does not alter any flags. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: e2bba34ac3bc76a0c42adc390413f358ae0566e8.1491597120.git.jcody@redhat.com
2017-04-24block: code movementJeff Cody1-5/+5
Move bdrv_is_read_only() up with its friends. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Message-id: 73b2399459760c32506f9407efb9dddb3a2789de.1491597120.git.jcody@redhat.com
2017-04-24block: honor BDRV_O_ALLOW_RDWR when clearing bs->read_onlyJeff Cody1-0/+7
The BDRV_O_ALLOW_RDWR flag allows / prohibits the changing of the BDS 'read_only' state, but there are a few places where it is ignored. In the bdrv_set_read_only() helper, make sure to honor the flag. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: be2e5fb2d285cbece2b6d06bed54a6f56520d251.1491597120.git.jcody@redhat.com
2017-04-24block: do not set BDS read_only if copy_on_read enabledJeff Cody1-1/+9
A few block drivers will set the BDS read_only flag from their .bdrv_open() function. This means the bs->read_only flag could be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ flag check occurs prior to the call to bdrv->bdrv_open(). This adds an error return to bdrv_set_read_only(), and an error will be return if we try to set the BDS to read_only while copy_on_read is enabled. This patch also changes the behavior of vvfat. Before, vvfat could override the drive 'readonly' flag with its own, internal 'rw' flag. For instance, this -drive parameter would result in a writable image: "-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on" This is not correct. Now, attempting to use the above -drive parameter will result in an error (i.e., 'rw' is incompatible with 'readonly=on'). Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
2017-04-24block: add bdrv_set_read_only() helper functionJeff Cody1-0/+5
We have a helper wrapper for checking for the BDS read_only flag, add a helper wrapper to set the read_only flag as well. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
2017-04-24block: Make errp the last parameter of bdrv_img_createFam Zheng1-2/+2
Signed-off-by: Fam Zheng <famz@redhat.com> Message-Id: <20170421122710.15373-6-famz@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-11block/io: Comment out permission assertionsMax Reitz1-1/+5
In case of block migration, there may be writes to BlockBackends that do not have the write permission taken. Before this issue is fixed (which is not going to happen in 2.9), we therefore cannot assert that this is the case. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Tested-by: Kevin Wolf <kwolf@redhat.com> Message-id: 20170411145050.31290-1-mreitz@redhat.com Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-04-11block: Introduce bdrv_coroutine_enterFam Zheng1-0/+5
Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11block: Quiesce old aio context during bdrv_set_aio_contextFam Zheng1-2/+5
The fact that the bs->aio_context is changing can confuse the dataplane iothread, because of the now fine granularity aio context lock. bdrv_drain should rather be a bdrv_drained_begin/end pair, but since bs->aio_context is changing, we can just use aio_disable_external and bdrv_parent_drained_begin. Reported-by: Ed Swierk <eswierk@skyportsystems.com> Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-07block: Assert attached child node has right aio contextFam Zheng1-0/+4
Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-03block: Document -drive problematic code and bugsMarkus Armbruster1-3/+45
-blockdev and blockdev_add convert their arguments via QObject to BlockdevOptions for qmp_blockdev_add(), which converts them back to QObject, then to a flattened QDict. The QDict's members are typed according to the QAPI schema. -drive converts its argument via QemuOpts to a (flat) QDict. This QDict's members are all QString. Thus, the QType of a flat QDict member depends on whether it comes from -drive or -blockdev/blockdev_add, except when the QAPI type maps to QString, which is the case for 'str' and enumeration types. The block layer core extracts generic configuration from the flat QDict, and the block driver extracts driver-specific configuration. Both commonly do so by converting (parts of) the flat QDict to QemuOpts, which turns all values into strings. Not exactly elegant, but correct. However, A few places access the flat QDict directly: * Most of them access members that are always QString. Correct. * bdrv_open_inherit() accesses a boolean, carefully. Correct. * nfs_config() uses a QObject input visitor. Correct only because the visited type contains nothing but QStrings. * nbd_config() and ssh_config() use a QObject input visitor, and the visited types contain non-QStrings: InetSocketAddress members @numeric, @to, @ipv4, @ipv6. -drive works as long as you don't try to use them (they're all optional). @to is ignored anyway. Reproducer: -drive driver=ssh,server.host=h,server.port=22,server.ipv4,path=p -drive driver=nbd,server.type=inet,server.data.host=h,server.data.port=22,server.data.ipv4 both fail with "Invalid parameter type for 'data.ipv4', expected: boolean" Add suitable comments to all these places. Mark the buggy ones FIXME. "Fortunately", -drive's driver-specific options are entirely undocumented. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-id: 1490895797-29094-5-git-send-email-armbru@redhat.com [mreitz: Fixed two typos] Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-03-17block: quiesce AioContext when detaching from itPaolo Bonzini1-0/+7
While it is true that bdrv_set_aio_context only works on a single BlockDriverState subtree (see commit message for 53ec73e, "block: Use bdrv_drain to replace uncessary bdrv_drain_all", 2015-07-07), it works at the AioContext level rather than the BlockDriverState level. Therefore, it is also necessary to trigger pending bottom halves too, even if no requests are pending. For NBD this ensures that the aio_co_schedule of a previous call to nbd_attach_aio_context is completed before detaching from the old AioContext; it fixes qemu-iotest 094. Another similar bug happens when the VM is stopped and the virtio-blk dataplane irqfd is torn down. In this case it's possible that guest I/O gets stuck if notify_guest_bh was scheduled but doesn't run. Calling aio_poll from another AioContext is safe if non-blocking; races such as the one mentioned in the commit message for c9d1a56 ("block: only call aio_poll on the current thread's AioContext", 2016-10-28) are a concern for blocking calls. I considered other options, including: - moving the bs->wakeup mechanism to AioContext, and letting the caller check. This might work for virtio which has a clear place to wakeup (notify_place_bh) and check the condition (virtio_blk_data_plane_stop). For aio_co_schedule I couldn't find a clear place to check the condition. - adding a dummy oneshot bottom half and waiting for it to trigger. This has the complication that bottom half list is LIFO for historical reasons. There were performance issues caused by bottom half ordering in the past, so I decided against it for 2.9. Fixes: 99723548561978da8ef44cf804fb7912698f5d88 Reported-by: Max Reitz <mreitz@redhat.com> Reported-by: Halil Pasic <pasic@linux.vnet.ibm.com> Tested-by: Halil Pasic <pasic@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170314111157.14464-2-pbonzini@redhat.com Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-03-17block: Propagate error in bdrv_open_backing_fileFam Zheng1-0/+1
Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-17block: Always call bdrv_child_check_perm firstFam Zheng1-4/+9
bdrv_child_set_perm alone is not very usable because the caller must call bdrv_child_check_perm first. This is already encapsulated conveniently in bdrv_child_try_set_perm, so remove the other prototypes from the header and fix the one wrong caller, block/mirror.c. Signed-off-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-13block: Refresh filename after changing backing fileKevin Wolf1-0/+2
In bdrv_open_inherit(), the filename is refreshed after opening the backing file, but we neglected to do the same when the backing file changes later. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-13block: Remove check_new_perm from bdrv_replace_child()Kevin Wolf1-7/+14
All callers pass false now, so the parameter can go away again. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-08Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell1-62/+120
Block layer fixes for 2.9.0-rc0 # gpg: Signature made Tue 07 Mar 2017 14:59:18 GMT # gpg: using RSA key 0x7F09B272C88F2FD6 # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: (27 commits) commit: Don't use error_abort in commit_start block: Don't use error_abort in blk_new_open sheepdog: Support blockdev-add qapi-schema: Rename SocketAddressFlat's variant tcp to inet qapi-schema: Rename GlusterServer to SocketAddressFlat gluster: Plug memory leaks in qemu_gluster_parse_json() gluster: Don't duplicate qapi-util.c's qapi_enum_parse() gluster: Drop assumptions on SocketTransport names sheepdog: Implement bdrv_parse_filename() sheepdog: Use SocketAddress and socket_connect() sheepdog: Report errors in pseudo-filename more usefully sheepdog: Don't truncate long VDI name in _open(), _create() sheepdog: Fix snapshot ID parsing in _open(), _create, _goto() sheepdog: Mark sd_snapshot_delete() lossage FIXME sheepdog: Fix error handling sd_create() sheepdog: Fix error handling in sd_snapshot_delete() sheepdog: Defuse time bomb in sd_open() error handling block: Fix error handling in bdrv_replace_in_backing_chain() block: Handle permission errors in change_parent_backing_link() block: Ignore multiple children in bdrv_check_update_perm() ... Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-07block: More detailed syntax error reporting for JSON filenamesMarkus Armbruster1-2/+7
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <1488317230-26248-14-git-send-email-armbru@redhat.com>
2017-03-07qobject: Propagate parse errors through qobject_from_json()Markus Armbruster1-1/+1
The next few commits will put the errors to use where appropriate. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1488317230-26248-13-git-send-email-armbru@redhat.com>
2017-03-07block: Fix error handling in bdrv_replace_in_backing_chain()Kevin Wolf1-19/+6
When adding an Error parameter, bdrv_replace_in_backing_chain() would become nothing more than a wrapper around change_parent_backing_link(). So make the latter public, renamed as bdrv_replace_node(), and remove bdrv_replace_in_backing_chain(). Most of the callers just remove a node from the graph that they just inserted, so they can use &error_abort, but completion of a mirror job with 'replaces' set can actually fail. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07block: Handle permission errors in change_parent_backing_link()Kevin Wolf1-6/+44
Instead of just trying to change parents by parent over to reference @to instead of @from, and abort()ing whenever the permissions don't allow this, do proper permission checking beforehand and pass any error to the callers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07block: Ignore multiple children in bdrv_check_update_perm()Kevin Wolf1-13/+22
change_parent_backing_link() will need to update multiple BdrvChild objects at once. Checking permissions reference by reference doesn't work because permissions need to be consistent only with all parents moved to the new child. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07block: Factor out bdrv_replace_child_noperm()Kevin Wolf1-13/+25
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07block: Factor out should_update_child()Kevin Wolf1-15/+27
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-02-28block: Add Error parameter to bdrv_append()Kevin Wolf1-6/+17
Aborting on error in bdrv_append() isn't correct. This patch fixes it and lets the callers handle failures. Test case 085 needs a reference output update. This is caused by the reversed order of bdrv_set_backing_hd() and change_parent_backing_link() in bdrv_append(): When the backing file of the new node is set, the parent nodes are still pointing to the old top, so the backing blocker is now initialised with the node name rather than the BlockBackend name. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Add Error parameter to bdrv_set_backing_hd()Kevin Wolf1-7/+23
Not all callers of bdrv_set_backing_hd() know for sure that attaching the backing file will be allowed by the permission system. Return the error from the function rather than aborting. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Assertions for resize permissionKevin Wolf1-0/+3
This adds an assertion that ensures that the necessary resize permission has been granted before bdrv_truncate() is called. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Allow backing file links in change_parent_backing_link()Kevin Wolf1-4/+3
Now that the backing file child role implements .attach/.detach callbacks, nothing prevents us from modifying the graph even if that involves changing backing file links. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: BdrvChildRole.attach/detach() callbacksKevin Wolf1-35/+60
Backing files are somewhat special compared to other kinds of children because they are attached and detached using bdrv_set_backing_hd() rather than the normal set of functions, which does a few more things like setting backing blockers, toggling the BDRV_O_NO_BACKING flag, setting parent_bs->backing_file, etc. These special features are a reason why change_parent_backing_link() can't handle backing files yet. With abstracting the additional features into .attach/.detach callbacks, we get a step closer to a function that can actually deal with this. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Fix pending requests check in bdrv_append()Kevin Wolf1-2/+2
bdrv_append() cares about isolation of the node that it modifies, but not about activity in some subtree below it. Instead of using the recursive bdrv_requests_pending(), directly check bs->in_flight, which considers only the node in question. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add BdrvChildRole.stay_at_nodeKevin Wolf1-0/+3
When the parents' child links are updated in bdrv_append() or bdrv_replace_in_backing_chain(), this should affect all child links of BlockBackends or other nodes, but not on child links held for other purposes (like for setting permissions). This patch allows to control the behaviour per BdrvChildRole. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Include details on permission errors in messageKevin Wolf1-11/+56
Instead of just telling that there was some conflict, we can be specific and tell which permissions were in conflict and which way the conflict is. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Add BdrvChildRole.get_parent_desc()Kevin Wolf1-0/+9
For meaningful error messages in the permission system, we need to get some human-readable description of the parent of a BdrvChild. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add error parameter to blk_insert_bs()Kevin Wolf1-1/+4
Now that blk_insert_bs() requests the BlockBackend permissions for the node it attaches to, it can fail. Instead of aborting, pass the errors to the callers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add permissions to blk_new()Kevin Wolf1-1/+1
We want every user to be specific about the permissions it needs, so we'll pass the initial permissions as parameters to blk_new(). A user only needs to call blk_set_perm() if it wants to change the permissions after the fact. The permissions are stored in the BlockBackend and applied whenever a BlockDriverState should be attached in blk_insert_bs(). This does not include actually choosing the right set of permissions everywhere yet. Instead, the usual FIXME comment is added to each place and will be addressed in individual patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Request real permissions in bdrv_attach_child()Kevin Wolf1-2/+8
Now that all block drivers with children tell us what permissions they need from each of their children, bdrv_attach_child() can use this information and make the right requirements while trying to attach new children. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Require .bdrv_child_perm() with child nodesKevin Wolf1-2/+4
All block drivers that can have child nodes implement .bdrv_child_perm() now. Make this officially a requirement by asserting that only drivers without children can omit .bdrv_child_perm(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28vvfat: Implement .bdrv_child_perm()Kevin Wolf1-1/+1
vvfat is the last remaining driver that can have children, but doesn't implement .bdrv_child_perm() yet. The default handlers aren't suitable here, so let's implement a very simple driver-specific one that protects the internal child from being used by other users as good as our permissions permit. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Default .bdrv_child_perm() for format driversKevin Wolf1-0/+44
Almost all format drivers have the same characteristics as far as permissions are concerned: They have one or more children for storing their own data and, more importantly, metadata (can be written to and grow even without external write requests, must be protected against other writers and present consistent data) and optionally a backing file (this is just data, so like for a filter, it only depends on what the parent nodes need). This provides a default implementation that can be shared by most of our format drivers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Default .bdrv_child_perm() for filter driversKevin Wolf1-0/+23
Most filters need permissions related to read and write for their children, but only if the node has a parent that wants to use the same operation on the filter. The same is true for resize. This adds a default implementation that simply forwards all necessary permissions to all children of the node and leaves the other permissions unchanged. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Involve block drivers in permission grantingKevin Wolf1-4/+202
In many cases, the required permissions of one node on its children depend on what its parents require from it. For example, the raw format or most filter drivers only need to request consistent reads if that's something that one of their parents wants. In order to achieve this, this patch introduces two new BlockDriver callbacks. The first one lets drivers first check (recursively) whether the requested permissions can be set; the second one actually sets the new permission bitmask. Also add helper functions that drivers can use in their implementation of the callbacks to update their permissions on a specific child. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28block: Let callers request permissions when attaching a child nodeKevin Wolf1-8/+58
When attaching a node as a child to a new parent, the required and shared permissions for this parent are checked against all other parents of the node now, and an error is returned if there is a conflict. This allows error returns to a function that previously always succeeded, and the same is true for quite a few callers and their callers. Converting all of them within the same patch would be too much, so for now everyone tells that they don't need any permissions and allow everyone else to do anything. This way we can use &error_abort initially and convert caller by caller to pass actual permission requirements and implement error handling. All these places are marked with FIXME comments and it will be the job of the next patches to clean them up again. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add Error argument to bdrv_attach_child()Kevin Wolf1-3/+13
It will have to return an error soon, so prepare the callers for it. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-26Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into stagingPeter Maydell1-95/+170
Block layer patches # gpg: Signature made Fri 24 Feb 2017 18:08:26 GMT # gpg: using RSA key 0x7F09B272C88F2FD6 # gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" # Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6 * remotes/kevin/tags/for-upstream: tests: Use opened block node for block job tests vvfat: Use opened node as backing file block: Add bdrv_new_open_driver() block: Factor out bdrv_open_driver() block: Use BlockBackend for image probing block: Factor out bdrv_open_child_bs() block: Attach bs->file only during .bdrv_open() block: Pass BdrvChild to bdrv_truncate() mirror: Resize active commit base in mirror_run() qcow2: Use BB for resizing in qcow2_amend_options() blockdev: Use BlockBackend to resize in qmp_block_resize() iotests: Fix another race in 030 qemu-img: Improve documentation for PREALLOC_MODE_FALLOC qemu-img: Truncate before full preallocation qemu-img: Add tests for raw image preallocation qemu-img: Do not truncate before preallocation qemu-iotests: redirect nbd server stdout to /dev/null qemu-iotests: add ability to exclude certain protocols from tests qemu-iotests: Test 137 only supports 'file' protocol Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-02-24block: Add bdrv_new_open_driver()Kevin Wolf1-1/+29
This function allows to create more or less normal BlockDriverStates even for BlockDrivers that aren't globally registered (e.g. helper filters for block jobs). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Factor out bdrv_open_driver()Kevin Wolf1-47/+65
This is a function that doesn't do any option parsing, but just does some basic BlockDriverState setup and calls the .bdrv_open() function of the block driver. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Use BlockBackend for image probingKevin Wolf1-17/+19
This fixes the use of a parent-less BdrvChild in bdrv_open_inherit() by converting it into a BlockBackend. Which is exactly what it should be, image probing is an external, standalone user of a node. The requests can't be considered to originate from the format driver node because that one isn't even opened yet. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Factor out bdrv_open_child_bs()Kevin Wolf1-24/+37
This is the part of bdrv_open_child() that opens a BDS with option inheritance, but doesn't attach it as a child to the parent yet. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24block: Attach bs->file only during .bdrv_open()Kevin Wolf1-11/+24
The way that attaching bs->file worked was a bit unusual in that it was the only child that would be attached to a node which is not opened yet. Because of this, the block layer couldn't know yet which permissions the driver would eventually need. This patch moves the point where bs->file is attached to the beginning of the individual .bdrv_open() implementations, so drivers already know what they are going to do with the child. This is also more consistent with how driver-specific children work. For a moment, bdrv_open() gets its own BdrvChild to perform image probing, but instead of directly assigning this BdrvChild to the BDS, it becomes a temporary one and the node name is passed as an option to the drivers, so that they can simply use bdrv_open_child() to create another reference for their own use. This duplicated child for (the not opened yet) bs is not the final state, a follow-up patch will change the image probing code to use a BlockBackend, which is completely independent of bs. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>