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2014-12-10blockdev: check for BLOCK_OP_TYPE_INTERNAL_SNAPSHOTStefan Hajnoczi1-0/+4
The BLOCK_OP_TYPE_INTERNAL_SNAPSHOT op blocker exists but was never used! Let's fix that so internal snapshots can be blocked. [Fixed s/external/internal/ typo as pointed out by Paolo Bonzini and Max Reitz. --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1416566940-4430-5-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: acquire AioContext in QMP 'transaction' actionsStefan Hajnoczi1-1/+51
The transaction QMP command performs operations atomically on a group of drives. This command needs to acquire AioContext in order to work safely when virtio-blk dataplane IOThreads are accessing drives. The transactional nature of the command means that actions are split into prepare, commit, abort, and clean functions. Acquire the AioContext in prepare and don't release it until one of the other functions is called. This prevents the IOThread from running the AioContext before the transaction has completed. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1416566940-4430-4-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: drop unnecessary DriveBackupState field assignmentStefan Hajnoczi1-2/+0
drive_backup_prepare() assigns DriveBackupState fields to NULL in the error path. This is unnecessary because the DriveBackupState is allocated using g_malloc0() and other functions like external_snapshot_prepare() already rely on this. Do not explicitly assign fields to NULL so that the error path is concise and does not require modification when fields are added to DriveBackupState. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1416566940-4430-3-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: update outdated qmp_transaction() commentsStefan Hajnoczi1-10/+6
Originally the transaction QMP command was just for taking snapshots. The command became more general when drive-backup and abort were added. It is more accurate to say the command is about performing operations on an atomic group than to say it is about snapshots. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1416566940-4430-2-git-send-email-stefanha@redhat.com Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: acquire AioContext in change-backing-fileStefan Hajnoczi1-6/+13
Add dataplane support to the change-backing-file QMP commands. By acquiring the AioContext we avoid race conditions with the dataplane thread which may also be accessing the BlockDriverState. Note that this command operates on both bs and a node in its chain (image_bs). The bdrv_chain_contains(bs, image_bs) check guarantees that bs and image_bs are in the same AioContext. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: acquire AioContext in eject, change, and block_passwdStefan Hajnoczi1-7/+29
By acquiring the AioContext we avoid race conditions with the dataplane thread which may also be accessing the BlockDriverState. Fix up eject, change, and block_passwd in a single patch because qmp_eject() and qmp_change_blockdev() both call eject_device(). Also fix block_passwd while we're tackling a command that takes a block encryption password. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: check for BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETEStefan Hajnoczi1-0/+4
The BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE op blocker exists but was never used! Let's fix that so snapshot delete can be blocked. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10blockdev: acquire AioContext in blockdev-snapshot-delete-internal-syncStefan Hajnoczi1-3/+13
Add dataplane support to the blockdev-snapshot-delete-internal-sync QMP command. By acquiring the AioContext we avoid race conditions with the dataplane thread which may also be accessing the BlockDriverState. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-11-03block: let commit blockjob run in BDS AioContextStefan Hajnoczi1-9/+20
The commit block job must run in the BlockDriverState AioContext so that it works with dataplane. Acquire the AioContext in blockdev.c so starting the block job is safe. One detail here is that the bdrv_drain_all() must be moved inside the aio_context_acquire() region so requests cannot sneak in between the drain and acquire. The completion code in block/commit.c must perform backing chain manipulation and bdrv_reopen() from the main loop. Use block_job_defer_to_main_loop() to achieve that. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-11-git-send-email-stefanha@redhat.com
2014-11-03block: let mirror blockjob run in BDS AioContextStefan Hajnoczi1-11/+27
The mirror block job must run in the BlockDriverState AioContext so that it works with dataplane. Acquire the AioContext in blockdev.c so starting the block job is safe. Note that to_replace is treated separately from other BlockDriverStates in that it does not need to be in the same AioContext. Explicitly acquire/release to_replace's AioContext when accessing it. The completion code in block/mirror.c must perform BDS graph manipulation and bdrv_reopen() from the main loop. Use block_job_defer_to_main_loop() to achieve that. The bdrv_drain_all() call is not allowed outside the main loop since it could lead to lock ordering problems. Use bdrv_drain(bs) instead because we have acquired the AioContext so nothing else can sneak in I/O. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-10-git-send-email-stefanha@redhat.com
2014-11-03block: let stream blockjob run in BDS AioContextStefan Hajnoczi1-4/+12
The stream block job must run in the BlockDriverState AioContext so that it works with dataplane. The basics of acquiring the AioContext are easy in blockdev.c. The tricky part is the completion code which drops part of the backing file chain. This must be done in the main loop where bdrv_unref() and bdrv_close() are safe to call. Use block_job_defer_to_main_loop() to achieve that. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-9-git-send-email-stefanha@redhat.com
2014-11-03block: let backup blockjob run in BDS AioContextStefan Hajnoczi1-7/+16
The backup block job must run in the BlockDriverState AioContext so that it works with dataplane. The basics of acquiring the AioContext are easy in blockdev.c. The completion code in block/backup.c must call bdrv_unref() from the main loop. Use block_job_defer_to_main_loop() to achieve that. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-8-git-send-email-stefanha@redhat.com
2014-11-03blockdev: add note that block_job_cb() must be thread-safeStefan Hajnoczi1-0/+5
This function is correct but we should document the constraint that everything must be thread-safe. Emitting QMP events and scheduling BHs are both thread-safe so nothing needs to be done here. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-5-git-send-email-stefanha@redhat.com
2014-11-03blockdev: acquire AioContext in blockdev_mark_auto_del()Stefan Hajnoczi1-0/+7
When an emulated storage controller is unrealized it will call blockdev_mark_auto_del(). This will cancel any running block job (and that eventually releases its reference to the BDS so it can be freed). Since the block job may be executing in another AioContext we must acquire/release to ensure thread safety. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-4-git-send-email-stefanha@redhat.com
2014-11-03blockdev: acquire AioContext in do_qmp_query_block_jobs_one()Stefan Hajnoczi1-0/+6
Make sure that query-block-jobs acquires the BlockDriverState AioContext so that the blockjob isn't running in another thread while we access its state. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-3-git-send-email-stefanha@redhat.com
2014-11-03block: acquire AioContext in generic blockjob QMP commandsStefan Hajnoczi1-13/+39
block-job-set-speed, block-job-cancel, block-job-pause, block-job-resume, and block-job-complete must acquire the BlockDriverState AioContext so that it is safe to access bs. At the moment bs->job is always NULL when dataplane is active because op blockers prevent blockjobs from starting. Once the rest of the blockjob API has been made aware of AioContext we can drop the op blocker. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1413889440-32577-2-git-send-email-stefanha@redhat.com
2014-10-20block: Lift device model API into BlockBackendMarkus Armbruster1-5/+5
Move device model attachment / detachment and the BlockDevOps device model callbacks and their wrappers from BlockDriverState to BlockBackend. Wrapper calls in block.c change from bdrv_dev_FOO_cb(bs, ...) to if (bs->blk) { bdrv_dev_FOO_cb(bs->blk, ...); } No change, because both bdrv_dev_change_media_cb() and bdrv_dev_resize_cb() do nothing when no device model is attached, and a device model can be attached only when bs->blk. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Convert qmp_eject(), qmp_change_blockdev() to BlockBackendMarkus Armbruster1-8/+12
Much more command code needs conversion. I'm converting these now because they're using bdrv_dev_* functions, which I'm about to lift into BlockBackend. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Fix blockdev-add not to create DriveInfoMarkus Armbruster1-15/+7
blockdev_init() always creates a DriveInfo, but only drive_new() fills it in. qmp_blockdev_add() leaves it blank. This results in a drive with type = IF_IDE, bus = 0, unit = 0. Screwed up in commit ee13ed1c. Board initialization code looking for IDE drive (0,0) can pick up one of these bogus drives. The QMP command has to execute really early to be visible. Not sure how likely that is in practice. Fix by creating DriveInfo in drive_new(). Block backends created by blockdev-add don't get one. Breaks the test for "has been created by qmp_blockdev_add()" in blockdev_mark_auto_del() and do_drive_del(), because it changes the value of dinfo && !dinfo->enable_auto_del from true to false. Simply test !dinfo instead. Leaves DriveInfo member enable_auto_del unused. Drop it. A few places assume a block backend always has a DriveInfo. Fix them up. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Drop superfluous DriveInfo member idMarkus Armbruster1-3/+2
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20hw: Convert from BlockDriverState to BlockBackend, mostlyMarkus Armbruster1-9/+3
Device models should access their block backends only through the block-backend.h API. Convert them, and drop direct includes of inappropriate headers. Just four uses of BlockDriverState are left: * The Xen paravirtual block device backend (xen_disk.c) opens images itself when set up via xenbus, bypassing blockdev.c. I figure it should go through qmp_blockdev_add() instead. * Device model "usb-storage" prompts for keys. No other device model does, and this one probably shouldn't do it, either. * ide_issue_trim_cb() uses bdrv_aio_discard() instead of blk_aio_discard() because it fishes its backend out of a BlockAIOCB, which has only the BlockDriverState. * PC87312State has an unused BlockDriverState[] member. The next two commits take care of the latter two. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Eliminate DriveInfo member bdrv, use blk_by_legacy_dinfo()Markus Armbruster1-4/+3
The patch is big, but all it really does is replacing dinfo->bdrv by blk_bs(blk_by_legacy_dinfo(dinfo)) The replacement is repetitive, but the conversion of device models to BlockBackend is imminent, and will shorten it to just blk_legacy_dinfo(dinfo). Line wrapping muddies the waters a bit. I also omit tests whether dinfo->bdrv is null, because it never is. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Eliminate bdrv_iterate(), use bdrv_next()Markus Armbruster1-16/+11
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20blockdev: Eliminate drive_del()Markus Armbruster1-7/+2
drive_del() has become a trivial wrapper around blk_unref(). Get rid of it. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Make BlockBackend own its BlockDriverStateMarkus Armbruster1-6/+1
On BlockBackend destruction, unref its BlockDriverState. Replaces the callers' unrefs. This turns the pointer from BlockBackend to BlockDriverState into a strong reference, managed with bdrv_ref() / bdrv_unref(). The back-pointer remains weak. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Code motion to get rid of stubs/blockdev.cMarkus Armbruster1-11/+0
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Connect BlockBackend and DriveInfoMarkus Armbruster1-36/+37
Make the BlockBackend own the DriveInfo. Change blockdev_init() to return the BlockBackend instead of the DriveInfo. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Connect BlockBackend to BlockDriverStateMarkus Armbruster1-11/+8
Convenience function blk_new_with_bs() creates a BlockBackend with its BlockDriverState. Callers have to unref both. The commit after next will relieve them of the need to unref the BlockDriverState. Complication: due to the silly way drive_del works, we need a way to hide a BlockBackend, just like bdrv_make_anon(). To emphasize its "special" status, give the function a suitably off-putting name: blk_hide_on_behalf_of_do_drive_del(). Unfortunately, hiding turns the BlockBackend's name into the empty string. Can't avoid that without breaking the blk->bs->device_name equals blk->name invariant. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: New BlockBackendMarkus Armbruster1-1/+12
A block device consists of a frontend device model and a backend. A block backend has a tree of block drivers doing the actual work. The tree is managed by the block layer. We currently use a single abstraction BlockDriverState both for tree nodes and the backend as a whole. Drawbacks: * Its API includes both stuff that makes sense only at the block backend level (root of the tree) and stuff that's only for use within the block layer. This makes the API bigger and more complex than necessary. Moreover, it's not obvious which interfaces are meant for device models, and which really aren't. * Since device models keep a reference to their backend, the backend object can't just be destroyed. But for media change, we need to replace the tree. Our solution is to make the BlockDriverState generic, with actual driver state in a separate object, pointed to by member opaque. That lets us replace the tree by deinitializing and reinitializing its root. This special need of the root makes the data structure awkward everywhere in the tree. The general plan is to separate the APIs into "block backend", for use by device models, monitor and whatever other code dealing with block backends, and "block driver", for use by the block layer and whatever other code (if any) dealing with trees and tree nodes. Code dealing with block backends, device models in particular, should become completely oblivious of BlockDriverState. This should let us clean up both APIs, and the tree data structures. This commit is a first step. It creates a minimal "block backend" API: type BlockBackend and functions to create, destroy and find them. BlockBackend objects are created and destroyed exactly when root BlockDriverState objects are created and destroyed. "Root" in the sense of "in bdrv_states". They're not yet used for anything; that'll come shortly. A root BlockDriverState is created with bdrv_new_root(), so where to create a BlockBackend is obvious. Where these roots get destroyed isn't always as obvious. It is obvious in qemu-img.c, qemu-io.c and qemu-nbd.c, and in error paths of blockdev_init(), blk_connect(). That leaves destruction of objects successfully created by blockdev_init() and blk_connect(). blockdev_init() is used only by drive_new() and qmp_blockdev_add(). Objects created by the latter are currently indestructible (see commit 48f364d "blockdev: Refuse to drive_del something added with blockdev-add" and commit 2d246f0 "blockdev: Introduce DriveInfo.enable_auto_del"). Objects created by the former get destroyed by drive_del(). Objects created by blk_connect() get destroyed by blk_disconnect(). BlockBackend is reference-counted. Its reference count never exceeds one so far, but that's going to change. In drive_del(), the BB's reference count is surely one now. The BDS's reference count is greater than one when something else is holding a reference, such as a block job. In this case, the BB is destroyed right away, but the BDS lives on until all extra references get dropped. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20block: Split bdrv_new_root() off bdrv_new()Markus Armbruster1-1/+1
Creating an anonymous BDS can't fail. Make that obvious. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-03ide: Update ide_drive_get to be HBA agnosticJohn Snow1-0/+17
Instead of duplicating the logic for the if_ide (bus,unit) mappings, rely on the blockdev layer for managing those mappings for us, and use the drive_get_by_index call instead. This allows ide_drive_get to work for AHCI HBAs as well, and can be used in the Q35 initialization. Lastly, change the nature of the argument to ide_drive_get so that represents the number of total drives we can support, and not the total number of buses. This will prevent array overflows if the units-per-default-bus property ever needs to be adjusted for compatibility reasons. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Message-id: 1412187569-23452-5-git-send-email-jsnow@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-03blockdev: Allow overriding if_max_dev propertyJohn Snow1-1/+25
The if_max_devs table as in the past been an immutable default that controls the mapping of index => (bus,unit) for all boards and all HBAs for each interface type. Since adding this mapping information to the HBA device itself is currently unwieldly from the perspective of retrieving this information at option parsing time (e.g, within drive_new), we consider the alternative of marking the if_max_devs table mutable so that later configuration and initialization can adjust the mapping at will, but only up until a drive is added, at which point the mapping is finalized. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-id: 1412187569-23452-3-git-send-email-jsnow@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-03blockdev: Orphaned drive searchJohn Snow1-0/+21
When users use command line options like -hda, -cdrom, or even -drive if=ide, it is up to the board initialization routines to pick up these drives and create backing devices for them. Some boards, like Q35, have not been doing this. However, there is no warning explaining why certain drive specifications are just silently ignored, so this function adds a check to print some warnings to assist users in debugging these sorts of issues in the future. This patch will not warn about drives added with if_none, for which it is not possible to tell in advance if the omission of a backing device is an issue. A warning in these cases is considered appropriate. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Message-id: 1412187569-23452-2-git-send-email-jsnow@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-03Modify qemu_opt_rename to realize renaming all items in optsJun Li1-0/+4
Add realization of rename all items in opts for qemu_opt_rename. e.g: When add bps twice in command line, need to rename all bps to throttling.bps-total. This patch solved following bug: Bug 1145586 - qemu-kvm will give strange hint when add bps twice for a drive ref:https://bugzilla.redhat.com/show_bug.cgi?id=1145586 [Resolved conflict with commit 5abbf0ee4d87c695deb1c3fca9bb994b93a3e3be ("block: Catch simultaneous usage of options and their aliases"). Check for simultaneous use first, and then loop over all options. --Stefan] Signed-off-by: Jun Li <junmuzi@gmail.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1411537527-16715-1-git-send-email-junmuzi@gmail.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-10-03block: Drop superfluous conditionals around qemu_opts_del()Markus Armbruster1-3/+1
Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-id: 1411999675-14533-1-git-send-email-armbru@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-25block: Catch simultaneous usage of options and their aliasesKevin Wolf1-2/+14
While thinking about precedence of conflicting block device options from different sources, I noticed that you can specify both an option and its legacy alias at the same time (e.g. readonly=on,read-only=off). Rather than specifying the order of precedence, we should simply forbid such combinations. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Markus Armbruster <armbru@redhat.com>
2014-09-25block: Specify -drive legacy option aliases in arrayKevin Wolf1-15/+24
Instead of a series of qemu_opt_rename() calls, use an array that contains all of the renames and call qemu_opt_rename() in a loop. This will keep the code readable even when we add an error return to qemu_opt_rename(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Reviewed-by: Markus Armbruster <armbru@redhat.com>
2014-09-25block: Keep DriveInfo alive until BlockDriverState diesMarkus Armbruster1-5/+8
If the BDS's refcnt > 0, drive_del() destroys the DriveInfo, but not the BDS. This can happen in three places: * Device model destruction during unplug: blockdev_auto_del() * Xen IDE unplug: pci_piix3_xen_ide_unplug() * drive_del command when no device model is attached: do_drive_del() The other callers of drive_del are on error paths where refcnt == 1. If the user somehow manages to plug in a device model using a BDS that has gone through drive_del(), the legacy configuration passed in DriveInfo doesn't reach the device model, and automatic deletion on unplug doesn't work. Worse, some device models such as scsi-disk crash when DriveInfo doesn't exist. This is theoretical; I didn't research an actual reproducer. The problem was introduced when we replaced DriveInfo reference counting by BDS reference counting in commit a94a3fa..fa510eb. Fix by keeping DriveInfo alive until its BDS dies. This affects qemu_drive_opts: now you can't reuse the same ID for new drive options until the BDS dies. Before, you could, but since the code always attempts to create a BDS with the same ID next, the enclosing operation "create a new drive" failed anyway. Different error path, same result. Unfortunately, the fix involves use of blockdev.c stuff from block.c, which is a layering violation. Fortunately, my forthcoming BlockBackend work will get rid of it again. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-25blockdev: Disentangle BlockDriverState and DriveInfo creationMarkus Armbruster1-17/+20
blockdev_init() mixes up BlockDriverState and DriveInfo initialization Finish the BlockDriverState job before starting to mess with DriveInfo. Easier on the eyes. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-11blockdev: Refuse to drive_del something added with blockdev-addMarkus Armbruster1-1/+9
For some device models, the guest can prevent unplug. Some users need a way to forcibly revoke device model access to the block backend then, so the underlying images can be safely used for something else. drive_del lets you do that. Unfortunately, it conflates revoking access with destroying the backend. Commit 9063f81 made drive_del immediately destroy the root BDS. Nice: the device name becomes available for reuse immediately. Not so nice: the device model's pointer to the root BDS dangles, and we're prone to crash when the memory gets reused. Commit d22b2f4 fixed that by hiding the root BDS instead of destroying it. Destruction only happens on unplug. "Hiding" means removing it from bdrv_states and graph_bdrv_states; see bdrv_make_anon(). This "destroy on revoke" is a misfeature we don't want to carry forward to blockdev-add, just like "destroy on unplug" (commit 2d246f0). So make drive_del fail on anything added with blockdev-add. We'll add separate QMP commands to revoke device model access and to destroy backends. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-08rename parse_enum_option to qapi_enum_parse and make it publicPeter Lieven1-24/+6
relaxing the license to LGPLv2+ is intentional. Suggested-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit.canet@nodalink.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29block: acquire AioContext in do_drive_del()Stefan Hajnoczi1-0/+7
Make drive_del safe for dataplane where another thread may be running the BlockDriverState's AioContext. Note the assumption that AioContext's lifetime exceeds DriveInfo and BlockDriverState. We release AioContext after DriveInfo and BlockDriverState are potentially freed. This is clearly safe with the global AioContext but also with -object iothread and implicit iothreads created by -device virtio-blk-pci,x-data-plane=on (their lifetime is tied to DeviceState, not BlockDriverState). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-29blockdev: fix drive-mirror 'granularity' error messageStefan Hajnoczi1-2/+3
Name the 'granularity' parameter and give its expected value range. Previously the device name was mistakenly reported as the parameter name. Note that the error class is unchanged from ERROR_CLASS_GENERIC_ERROR. Reported-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
2014-08-20block: acquire AioContext in qmp_block_resize()Stefan Hajnoczi1-3/+10
Make block_resize safe for dataplane where another thread may be running the BlockDriverState's AioContext. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-08-20block: Use g_new() & friends where that makes obvious senseMarkus Armbruster1-1/+1
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer, for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. Patch created with Coccinelle, with two manual changes on top: * Add const to bdrv_iterate_format() to keep the types straight * Convert the allocation in bdrv_drop_intermediate(), which Coccinelle inexplicably misses Coccinelle semantic patch: @@ type T; @@ -g_malloc(sizeof(T)) +g_new(T, 1) @@ type T; @@ -g_try_malloc(sizeof(T)) +g_try_new(T, 1) @@ type T; @@ -g_malloc0(sizeof(T)) +g_new0(T, 1) @@ type T; @@ -g_try_malloc0(sizeof(T)) +g_try_new0(T, 1) @@ type T; expression n; @@ -g_malloc(sizeof(T) * (n)) +g_new(T, n) @@ type T; expression n; @@ -g_try_malloc(sizeof(T) * (n)) +g_try_new(T, n) @@ type T; expression n; @@ -g_malloc0(sizeof(T) * (n)) +g_new0(T, n) @@ type T; expression n; @@ -g_try_malloc0(sizeof(T) * (n)) +g_try_new0(T, n) @@ type T; expression p, n; @@ -g_realloc(p, sizeof(T) * (n)) +g_renew(T, p, n) @@ type T; expression p, n; @@ -g_try_realloc(p, sizeof(T) * (n)) +g_try_renew(T, p, n) Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-07-01block: add backing-file option to block-streamJeff Cody1-4/+19
On some image chains, QEMU may not always be able to resolve the filenames properly, when updating the backing file of an image after a block job. For instance, certain relative pathnames may fail, or drives may have been specified originally by file descriptor (e.g. /dev/fd/???), or a relative protocol pathname may have been used. In these instances, QEMU may lack the information to be able to make the correct choice, but the user or management layer most likely does have that knowledge. With this extension to the block-stream api, the user is able to change the backing file of the active layer as part of the block-stream operation. This allows the change to be 'safe', in the sense that if the attempt to write the active image metadata fails, then the block-stream operation returns failure, without disrupting the guest. If a backing file string is not specified in the command, the backing file string to use is determined in the same manner as it was previously. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: extend block-commit to accept a string for the backing fileJeff Cody1-1/+7
On some image chains, QEMU may not always be able to resolve the filenames properly, when updating the backing file of an image after a block commit. For instance, certain relative pathnames may fail, or drives may have been specified originally by file descriptor (e.g. /dev/fd/???), or a relative protocol pathname may have been used. In these instances, QEMU may lack the information to be able to make the correct choice, but the user or management layer most likely does have that knowledge. With this extension to the block-commit api, the user is able to change the backing file of the overlay image as part of the block-commit operation. This allows the change to be 'safe', in the sense that if the attempt to write the overlay image metadata fails, then the block-commit operation returns failure, without disrupting the guest. If the commit top is the active layer, then specifying the backing file string will be treated as an error (there is no overlay image to modify in that case). If a backing file string is not specified in the command, the backing file string to use is determined in the same manner as it was previously. Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: add QAPI command to allow live backing file changeJeff Cody1-0/+79
This allows a user to make a live change to the backing file recorded in an open image. The image file to modify can be specified 2 ways: 1) image filename 2) image node-name Note: this does not cause the backing file itself to be reopened; it merely changes the backing filename in the image file structure, and in internal BDS structures. It is the responsibility of the user to pass a filename string that can be resolved when the image chain is reopened, and the filename string is not validated. A good analogy for this command is that it is a live version of 'qemu-img rebase -u', with respect to changing the backing file string. [Jeff is offline so I respun this patch in his absence. Dropped image filename since using node-name is preferred and this is a new command. No need to introduce the limitations of finding images by filename. --Stefan] Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01block: make 'top' argument to block-commit optionalJeff Cody1-2/+14
Now that active layer block-commit is supported, the 'top' argument no longer needs to be mandatory. Change it to optional, with the default being the active layer in the device chain. [kwolf: Rebased and resolved conflict in tests/qemu-iotests/040] Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-06-27block: Add replaces argument to drive-mirrorBenoît Canet1-1/+30
drive-mirror will bdrv_swap the new BDS named node-name with the one pointed by replaces when the mirroring is finished. Signed-off-by: Benoit Canet <benoit@irqsave.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-15 03:50:29 +0000