Commit Graph

328 Commits

Author SHA1 Message Date
Alberto Garcia
81e5f78a9f block: use bdrv_get_device_or_node_name() in error messages
There are several error messages that identify a BlockDriverState by
its device name. However those errors can be produced in nodes that
don't have a device name associated.

In those cases we should use bdrv_get_device_or_node_name() to fall
back to the node name and produce a more meaningful message. The
messages are also updated to use the more generic term 'node' instead
of 'device'.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 9823a1f0514fdb0692e92868661c38a9e00a12d6.1428485266.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-04-28 15:36:09 +02:00
Fam Zheng
751ebd76e6 blockjob: Allow nested pause
This patch changes block_job_pause to increase the pause counter and
block_job_resume to decrease it.

The counter will allow calling block_job_pause/block_job_resume
unconditionally on a job when we need to suspend the IO temporarily.

From now on, each block_job_resume must be paired with a block_job_pause
to keep the counter balanced.

The user pause from QMP or HMP will only trigger block_job_pause once
until it's resumed, this is achieved by adding a user_paused flag in
BlockJob.

One occurrence of block_job_resume in mirror_complete is replaced with
block_job_enter which does what is necessary.

In block_job_cancel, the cancel flag is good enough to instruct
coroutines to quit loop, so use block_job_enter to replace the unpaired
block_job_resume.

Upon block job IO error, user is notified about the entering to the
pause state, so this pause belongs to user pause, set the flag
accordingly and expect a matching QMP resume.

[Extended doc comments as suggested by Paolo Bonzini
<pbonzini@redhat.com>.
--Stefan]

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1428069921-2957-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-04-28 15:36:09 +02:00
Markus Armbruster
5b347c5410 block: Fix blockdev-backup not to use funky error class
Error classes are a leftover from the days of "rich" error objects.
New code should always use ERROR_CLASS_GENERIC_ERROR.  Commit
b7b9d39..7c6a4ab added uses of ERROR_CLASS_DEVICE_NOT_FOUND.  Replace
them.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-03-19 16:02:59 +01:00
Fam Zheng
a0e8544cf8 blockdev: Convert bdrv_find to blk_by_name
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1425296209-1476-4-git-send-email-famz@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-03-16 12:10:30 -04:00
Markus Armbruster
a8b18f8fd2 block: Simplify setting numeric options
Don't convert numbers to strings for use with qemu_opt_set(), simply
use qemu_opt_set_number() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-26 14:51:46 +01:00
Markus Armbruster
f43e47dbf6 QemuOpts: Drop qemu_opt_set(), rename qemu_opt_set_err(), fix use
qemu_opt_set() is a wrapper around qemu_opt_set() that reports the
error with qerror_report_err().

Most of its users assume the function can't fail.  Make them use
qemu_opt_set_err() with &error_abort, so that should the assumption
ever break, it'll break noisily.

Just two users remain, in util/qemu-config.c.  Switch them to
qemu_opt_set_err() as well, then rename qemu_opt_set_err() to
qemu_opt_set().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-26 14:49:31 +01:00
Markus Armbruster
cccb7967bd QemuOpts: Convert qemu_opt_set_bool() to Error, fix its use
Return the Error object instead of reporting it with
qerror_report_err().

Change callers that assume the function can't fail to pass
&error_abort, so that should the assumption ever break, it'll break
noisily.

Turns out all callers outside its unit test assume that.  We could
drop the Error ** argument, but that would make the interface less
regular, so don't.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-26 14:46:32 +01:00
Peter Maydell
c5c6d7f81a Clean up around error_get_pretty(), qerror_report_err()
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2015-02-18' into staging

Clean up around error_get_pretty(), qerror_report_err()

# gpg: Signature made Wed Feb 18 10:10:07 2015 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-error-2015-02-18:
  qemu-char: Avoid qerror_report_err() outside QMP command handlers
  qemu-img: Avoid qerror_report_err() outside QMP command handlers
  vl: Avoid qerror_report_err() outside QMP command handlers
  tpm: Avoid qerror_report_err() outside QMP command handlers
  numa: Avoid qerror_report_err() outside QMP command handlers
  net: Avoid qerror_report_err() outside QMP command handlers
  monitor: Avoid qerror_report_err() outside QMP command handlers
  monitor: Clean up around monitor_handle_fd_param()
  error: Use error_report_err() where appropriate
  error: New convenience function error_report_err()
  vhost-scsi: Improve error reporting for invalid vhostfd

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-02-26 07:01:08 +00:00
Peter Maydell
68b459eaa6 hmp: Normalize HMP command handler names
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Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2015-02-18' into staging

hmp: Normalize HMP command handler names

# gpg: Signature made Wed Feb 18 10:59:44 2015 GMT using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-monitor-2015-02-18:
  hmp: Name HMP info handler functions hmp_info_SUBCOMMAND()
  hmp: Name HMP command handler functions hmp_COMMAND()
  hmp: Clean up declarations for long-gone info handlers

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-02-25 13:14:37 +00:00
Markus Armbruster
3e5a50d64c hmp: Name HMP command handler functions hmp_COMMAND()
Some are called do_COMMAND() (old ones, usually), some hmp_COMMAND(),
and sometimes COMMAND pointlessly differs in spelling.

Normalize to hmp_COMMAND(), where COMMAND is exactly the command name
with '-' replaced by '_'.

Exceptions:

* do_device_add() and client_migrate_info() *not* renamed to
  hmp_device_add(), hmp_client_migrate_info(), because they're also
  QMP handlers.  They still need to be converted to QAPI.

* do_memory_dump(), do_physical_memory_dump(), do_ioport_read(),
  do_ioport_write() renamed do hmp_* instead of hmp_x(), hmp_xp(),
  hmp_i(), hmp_o(), because those names are too cryptic for my taste.

* do_info_help() renamed to hmp_info_help() instead of hmp_info(),
  because it only covers help.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-02-18 11:58:30 +01:00
Markus Armbruster
565f65d271 error: Use error_report_err() where appropriate
Coccinelle semantic patch:

    @@
    expression E;
    @@
    -    error_report("%s", error_get_pretty(E));
    -    error_free(E);
    +    error_report_err(E);
    @@
    expression E, S;
    @@
    -    error_report("%s", error_get_pretty(E));
    +    error_report_err(E);
    (
         exit(S);
    |
         abort();
    )

Trivial manual touch-ups in block/sheepdog.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-18 10:51:09 +01:00
Max Reitz
e4342ce5a2 blockdev: Use blk_new_open() in blockdev_init()
Due to different error propagation, this breaks tests 051 and 087; fix
their output.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1423162705-32065-6-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-02-16 15:07:18 +00:00
Markus Armbruster
4d2855a348 block: New bdrv_add_key(), convert monitor to use it
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1422524221-8566-4-git-send-email-armbru@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-02-06 11:46:32 -05:00
Markus Armbruster
2e3a0266bd blockdev: Eliminate silly QERR_BLOCK_JOB_NOT_ACTIVE macro
The QERR_ macros are leftovers from the days of "rich" error objects.
They're used with error_set() and qerror_report(), and expand into the
first *two* arguments.  This trickiness has become pointless.  Clean
this one up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1422524221-8566-3-git-send-email-armbru@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-02-06 11:46:32 -05:00
Markus Armbruster
24d6bffe8a blockdev: Give find_block_job() an Error ** parameter
When find_block_job() fails, all its callers build the same Error
object.  Build it in find_block_job() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1422524221-8566-2-git-send-email-armbru@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-02-06 11:46:32 -05:00
Fam Zheng
bb00021de0 block: Split BLOCK_OP_TYPE_COMMIT to BLOCK_OP_TYPE_COMMIT_{SOURCE, TARGET}
Like BLOCK_OP_TYPE_BACKUP_SOURCE and BLOCK_OP_TYPE_BACKUP_TARGET,
block-commit involves two asymmetric devices.

This change is not user-visible (yet), because commit only works with
device names.

But once we enable backing reference in blockdev-add, or specifying
node-name in block-commit command, we don't want the user to start two
commit jobs on the same backing chain, which will corrupt things because
of the final bdrv_swap.

Before we have per category blockers, splitting this type is still
better.

[Resolved virtio-blk dataplane conflict by replacing
BLOCK_OP_TYPE_COMMIT with both BLOCK_OP_TYPE_COMMIT_{SOURCE, TARGET}.
They are safe since the block job runs in the same AioContext as the
dataplane IOThread.
--Stefan]

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-01-13 13:43:29 +00:00
Fam Zheng
bd8baecddc block: Add blockdev-backup to transaction
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418899027-8445-4-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-01-13 11:47:56 +00:00
Fam Zheng
c29c1dd312 qmp: Add command 'blockdev-backup'
Similar to drive-backup, but this command uses a device id as target
instead of creating/opening an image file.

Also add blocker on target bs, since the target is also a named device
now.

Add check and report error for bs == target which became possible but is
an illegal case with introduction of blockdev-backup.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1418899027-8445-3-git-send-email-famz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-01-13 11:47:56 +00:00
Stefan Hajnoczi
3dc7ca3c97 blockdev: check for BLOCK_OP_TYPE_INTERNAL_SNAPSHOT
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>
2014-12-10 10:31:13 +01:00
Stefan Hajnoczi
5d6e96efb8 blockdev: acquire AioContext in QMP 'transaction' actions
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>
2014-12-10 10:31:13 +01:00
Stefan Hajnoczi
73f1f7564d blockdev: drop unnecessary DriveBackupState field assignment
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>
2014-12-10 10:31:13 +01:00
Stefan Hajnoczi
b756b9ce8a blockdev: update outdated qmp_transaction() comments
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>
2014-12-10 10:31:13 +01:00
Stefan Hajnoczi
729962f6db blockdev: acquire AioContext in change-backing-file
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>
2014-12-10 10:25:30 +01:00
Stefan Hajnoczi
e3442099a2 blockdev: acquire AioContext in eject, change, and block_passwd
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>
2014-12-10 10:25:30 +01:00
Stefan Hajnoczi
0b92885420 blockdev: check for BLOCK_OP_TYPE_INTERNAL_SNAPSHOT_DELETE
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>
2014-12-10 10:25:30 +01:00
Stefan Hajnoczi
4ef3982a99 blockdev: acquire AioContext in blockdev-snapshot-delete-internal-sync
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>
2014-12-10 10:25:30 +01:00
Stefan Hajnoczi
9e85cd5ce0 block: let commit blockjob run in BDS AioContext
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
5a7e7a0bad block: let mirror blockjob run in BDS AioContext
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
f3e69beb94 block: let stream blockjob run in BDS AioContext
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
761731b180 block: let backup blockjob run in BDS AioContext
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
723c5d93c5 blockdev: add note that block_job_cb() must be thread-safe
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
91fddb0db6 blockdev: acquire AioContext in blockdev_mark_auto_del()
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
69691e7270 blockdev: acquire AioContext in do_qmp_query_block_jobs_one()
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
2014-11-03 11:41:49 +00:00
Stefan Hajnoczi
3d948cdf37 block: acquire AioContext in generic blockjob QMP commands
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
2014-11-03 11:41:49 +00:00
Markus Armbruster
a7f53e26a6 block: Lift device model API into BlockBackend
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>
2014-10-20 14:03:50 +02:00
Markus Armbruster
6007cdd448 blockdev: Convert qmp_eject(), qmp_change_blockdev() to BlockBackend
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>
2014-10-20 14:03:50 +02:00
Markus Armbruster
26f8b3a847 blockdev: Fix blockdev-add not to create DriveInfo
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>
2014-10-20 14:03:50 +02:00
Markus Armbruster
d3aeb1b7da blockdev: Drop superfluous DriveInfo member id
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>
2014-10-20 14:03:50 +02:00
Markus Armbruster
4be746345f hw: Convert from BlockDriverState to BlockBackend, mostly
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>
2014-10-20 14:02:25 +02:00
Markus Armbruster
fa1d36df74 block: Eliminate DriveInfo member bdrv, use blk_by_legacy_dinfo()
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>
2014-10-20 13:41:27 +02:00
Markus Armbruster
fea68bb6e9 block: Eliminate bdrv_iterate(), use bdrv_next()
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
b9fe8a7a12 blockdev: Eliminate drive_del()
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
9ba10c95a4 block: Make BlockBackend own its BlockDriverState
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
8fb3c76c94 block: Code motion to get rid of stubs/blockdev.c
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
18e46a033d block: Connect BlockBackend and DriveInfo
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
7e7d56d9e0 block: Connect BlockBackend to BlockDriverState
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
26f54e9a3c block: New BlockBackend
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>
2014-10-20 13:41:26 +02:00
Markus Armbruster
e4e9986b1c block: Split bdrv_new_root() off bdrv_new()
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>
2014-10-20 13:41:26 +02:00
John Snow
d8f94e1bb2 ide: Update ide_drive_get to be HBA agnostic
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>
2014-10-03 10:30:33 +01:00
John Snow
21dff8cf38 blockdev: Allow overriding if_max_dev property
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>
2014-10-03 10:30:33 +01:00