Commit Graph

66 Commits

Author SHA1 Message Date
Eric Blake 51e72bc1dd qapi: Swap visit_* arguments for consistent 'name' placement
JSON uses "name":value, but many of our visitor interfaces were
called with visit_type_FOO(v, &value, name, errp).  This can be
a bit confusing to have to mentally swap the parameter order to
match JSON order.  It's particularly bad for visit_start_struct(),
where the 'name' parameter is smack in the middle of the
otherwise-related group of 'obj, kind, size' parameters! It's
time to do a global swap of the parameter ordering, so that the
'name' parameter is always immediately after the Visitor argument.

Additional reason in favor of the swap: the existing include/qjson.h
prefers listing 'name' first in json_prop_*(), and I have plans to
unify that file with the qapi visitors; listing 'name' first in
qapi will minimize churn to the (admittedly few) qjson.h clients.

Later patches will then fix docs, object.h, visitor-impl.h, and
those clients to match.

Done by first patching scripts/qapi*.py by hand to make generated
files do what I want, then by running the following Coccinelle
script to affect the rest of the code base:
 $ spatch --sp-file script `git grep -l '\bvisit_' -- '**/*.[ch]'`
I then had to apply some touchups (Coccinelle insisted on TAB
indentation in visitor.h, and botched the signature of
visit_type_enum() by rewriting 'const char *const strings[]' to
the syntactically invalid 'const char*const[] strings').  The
movement of parameters is sufficient to provoke compiler errors
if any callers were missed.

    // Part 1: Swap declaration order
    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_start_struct
    -(TV v, TObj OBJ, T1 ARG1, const char *name, T2 ARG2, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type bool, TV, T1;
    identifier ARG1;
    @@
     bool visit_optional
    -(TV v, T1 ARG1, const char *name)
    +(TV v, const char *name, T1 ARG1)
     { ... }

    @@
    type TV, TErr, TObj, T1;
    identifier OBJ, ARG1;
    @@
     void visit_get_next_type
    -(TV v, TObj OBJ, T1 ARG1, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj, T1, T2;
    identifier OBJ, ARG1, ARG2;
    @@
     void visit_type_enum
    -(TV v, TObj OBJ, T1 ARG1, T2 ARG2, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, T1 ARG1, T2 ARG2, TErr errp)
     { ... }

    @@
    type TV, TErr, TObj;
    identifier OBJ;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
     void VISIT_TYPE
    -(TV v, TObj OBJ, const char *name, TErr errp)
    +(TV v, const char *name, TObj OBJ, TErr errp)
     { ... }

    // Part 2: swap caller order
    @@
    expression V, NAME, OBJ, ARG1, ARG2, ERR;
    identifier VISIT_TYPE =~ "^visit_type_";
    @@
    (
    -visit_start_struct(V, OBJ, ARG1, NAME, ARG2, ERR)
    +visit_start_struct(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -visit_optional(V, ARG1, NAME)
    +visit_optional(V, NAME, ARG1)
    |
    -visit_get_next_type(V, OBJ, ARG1, NAME, ERR)
    +visit_get_next_type(V, NAME, OBJ, ARG1, ERR)
    |
    -visit_type_enum(V, OBJ, ARG1, ARG2, NAME, ERR)
    +visit_type_enum(V, NAME, OBJ, ARG1, ARG2, ERR)
    |
    -VISIT_TYPE(V, OBJ, NAME, ERR)
    +VISIT_TYPE(V, NAME, OBJ, ERR)
    )

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1454075341-13658-19-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-02-08 17:29:56 +01:00
Paolo Bonzini 1963f8d52e block: acquire in bdrv_query_image_info
NFS calls aio_poll inside bdrv_get_allocated_size.  This requires
acquiring the AioContext.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1450867706-19860-1-git-send-email-pbonzini@redhat.com
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-02-02 17:50:47 +01:00
Max Reitz 327032ce74 block/qapi: Emit tray_open only if there is a tray
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1454096953-31773-5-git-send-email-mreitz@redhat.com
2016-02-02 17:47:06 +01:00
Peter Maydell 80c71a241a block: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-20 13:36:23 +01:00
Fam Zheng 0fa296eb00 block/qapi: Clear err for further error
Since a5002d5 (block/qapi: allow best-effort query) we don't return at
this error, however err must be cleared before passing to
bdrv_query_snapshot_info_list below, as required by error API.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 1450779107-26765-1-git-send-email-famz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-01-07 21:30:17 +01:00
John Snow a5002d5302 block/qapi: allow best-effort query
For more complex BDS trees that can be created under normal circumstances,
we lose the ability to issue query commands because of our inability to
re-construct the absolute filename.

Instead, omit this field when it is a problem and present as much information
as we can.

This will change the expected output in iotest 110, where we will now see a
json filename and the lack of an absolute filename instead of an error.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1450122916-4706-6-git-send-email-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-12-18 14:36:17 +01:00
John Snow 5c9d9ca597 block/qapi: explicitly warn if !has_full_backing_filename
Disambiguate "Backing filename and full backing filename are equivalent"
from "full backing filename could not be determined."

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 1450122916-4706-4-git-send-email-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-12-18 14:36:17 +01:00
John Snow 12dcb1c018 block/qapi: always report full_backing_filename
Always report full_backing_filename, even if it's the same as
backing_filename. In the next patch, full_backing_filename may be
omitted if it cannot be generated instead of allowing e.g. drive_query
to abort if it runs into this scenario.

The presence or absence of the "full" field becomes useful information.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1450122916-4706-3-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-12-18 14:36:17 +01:00
John Snow 548e1ff379 block/qapi: do not redundantly print "actual path"
If it happens to match the backing path, that was the actual path.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1450122916-4706-2-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2015-12-18 14:36:17 +01:00
Eric Blake 1310a3d3bd qobject: Rename qtype_code to QType
The name QType matches our CODING_STYLE conventions for type names
in CamelCase.  It also matches the fact that we are already naming
all the enum members with a prefix of QTYPE, not QTYPE_CODE.  And
doing the rename will also make it easier for the next patch to use
QAPI for providing the enum, which also wants CamelCase type names.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1449033659-25497-3-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-12-17 08:21:28 +01:00
Markus Armbruster 903c341d57 block/qapi: Plug memory leak on query-block error path
Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-25 14:27:43 +01:00
Alberto Garcia 96e4dedaff block: Add average I/O queue depth to BlockDeviceTimedStats
This patch adds two new fields to BlockDeviceTimedStats that track the
average number of pending read and write requests for a block device.

The values are calculated for the period of time defined for that
interval.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: fd31fef53e2714f2f30d59ed58ca2f67ec9ab926.1446044837.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12 16:22:46 +01:00
Alberto Garcia 979e9b03fc block: Compute minimum, maximum and average I/O latencies
This patch keeps track of the minimum, maximum and average latencies
of I/O operations during a certain interval of time.

The values are exposed in the BlockDeviceTimedStats structure.

An option to define the intervals to collect these statistics will be
added in a separate patch.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: c7382dc89622c64f918d09f32815827772628f8e.1446044837.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12 16:22:45 +01:00
Alberto Garcia 362e9299b3 block: Allow configuring whether to account failed and invalid ops
This patch adds two options, "stats-account-invalid" and
"stats-account-failed", that can be used to decide whether invalid and
failed I/O operations must be used when collecting statistics for
latency and last access time.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: ebc7e5966511a342cad428a392c5f5ad56b15213.1446044837.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12 16:22:45 +01:00
Alberto Garcia 7ee12dafe9 block: Add statistics for failed and invalid I/O operations
This patch adds the block_acct_failed() and block_acct_invalid()
functions to allow keeping track of failed and invalid I/O operations.

The number of failed and invalid operations is exposed in
BlockDeviceStats.

We don't keep track of the time spent on invalid operations because
they are cancelled immediately when they are started.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: a7256ccb883a86356b1c6c46b5a29ed5448546a5.1446044837.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12 16:22:45 +01:00
Alberto Garcia cb38fffbc9 block: Add idle_time_ns to BlockDeviceStats
This patch adds the new field 'idle_time_ns' to the BlockDeviceStats
structure, indicating the time that has passed since the previous I/O
operation.

It also adds the block_acct_idle_time_ns() call, to ensure that all
references to the clock type used for accounting are in the same
place. This will later allow us to use a different clock for iotests.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 7d8cfcf931453e1a2443e6626e8c1edc347c7c8a.1446044837.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-12 16:22:45 +01:00
Alberto Garcia a0d64a61db throttle: Use bs->throttle_state instead of bs->io_limits_enabled
There are two ways to check for I/O limits in a BlockDriverState:

- bs->throttle_state: if this pointer is not NULL, it means that this
  BDS is member of a throttling group, its ThrottleTimers structure
  has been initialized and its I/O limits are ready to be applied.

- bs->io_limits_enabled: if true it means that the throttle_state
  pointer is valid _and_ the limits are currently enabled.

The latter is used in several places to check whether a BDS has I/O
limits configured, but what it really checks is whether requests
are being throttled or not. For example, io_limits_enabled can be
temporarily set to false in cases like bdrv_read_unthrottled() without
otherwise touching the throtting configuration of that BDS.

This patch replaces bs->io_limits_enabled with bs->throttle_state in
all cases where what we really want to check is the existence of I/O
limits, not whether they are currently enabled or not.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:25:47 +01:00
Max Reitz 5433c24f0f block: Prepare for NULL BDS
blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Max Reitz 373340b26c block: Move I/O status and error actions into BB
These options are only relevant for the user of a whole BDS tree (like a
guest device or a block job) and should thus be moved into the
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Max Reitz 7f0e9da6f1 block: Move BlockAcctStats into BlockBackend
As the comment above bdrv_get_stats() says, BlockAcctStats is something
which belongs to the device instead of each BlockDriverState. This patch
therefore moves it into the BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Max Reitz 53d8f9d8fb block: Remove wr_highest_sector from BlockAcctStats
BlockAcctStats contains statistics about the data transferred from and
to the device; wr_highest_sector does not fit in with the rest.

Furthermore, those statistics are supposed to be specific for a certain
device and not necessarily for a BDS (see the comment above
bdrv_get_stats()); on the other hand, wr_highest_sector may be a rather
important information to know for each BDS. When BlockAcctStats is
finally removed from the BDS, we will want to keep wr_highest_sector in
the BDS.

Finally, wr_highest_sector is renamed to wr_highest_offset and given the
appropriate meaning. Externally, it is represented as an offset so there
is no point in doing something different internally. Its definition is
changed to match that in qapi/block-core.json which is "the offset after
the greatest byte written to". Doing so should not cause any harm since
if external programs tried to calculate the volume usage by
(wr_highest_offset + 512) / volume_size, after this patch they will just
assume the volume to be full slightly earlier than before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Kevin Wolf 760e006384 block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.

After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16 15:34:29 +02:00
Kevin Wolf 9a4f4c3156 block: Convert bs->file to BdrvChild
This patch removes the temporary duplication between bs->file and
bs->file_child by converting everything to BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-16 15:34:29 +02:00
Markus Armbruster 4629ed1e98 qerror: Finally unused, clean up
Remove it except for two things in qerror.h:

* Two #include to be cleaned up separately to avoid cluttering this
  patch.

* The QERR_ macros.  Mark as obsolete.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Eric Blake fc48ffc39e qobject: Use 'bool' for qbool
We require a C99 compiler, so let's use 'bool' instead of 'int'
when dealing with boolean values.  There are few enough clients
to fix them all in one pass.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2015-06-22 17:40:00 +02:00
Alberto Garcia b8fe1694e5 throttle: add the name of the ThrottleGroup to BlockDeviceInfo
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 172df91f09c69c6f0440a697bbd1b3f95b077ee4.1433779731.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-06-12 14:00:00 +01:00
Alberto Garcia 76f4afb40f throttle: Add throttle group support
The throttle group support use a cooperative round robin scheduling
algorithm.

The principles of the algorithm are simple:
- Each BDS of the group is used as a token in a circular way.
- The active BDS computes if a wait must be done and arms the right
  timer.
- If a wait must be done the token timer will be armed so the token
  will become the next active BDS.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: f0082a86f3ac01c46170f7eafe2101a92e8fde39.1433779731.git.berto@igalia.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-06-12 14:00:00 +01:00
Markus Armbruster a7c3181628 qobject: Clean up around qtype_code
QTYPE_NONE is a sentinel value.  No QObject has this type code.
Document it properly.

Fix dump_qobject() to abort() on QTYPE_NONE, just like for any other
invalid type code.

Fix to_json() to abort() on all invalid type codes, not just
QTYPE_MAX.

Clean up Property member qtype's type: it's a qtype_code.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-05-11 08:59:07 -04:00
Alberto Garcia d5a8ee60a0 qmp: fill in the image field in BlockDeviceInfo
The image field in BlockDeviceInfo is supposed to contain an ImageInfo
object. However that is being filled in by bdrv_query_info(), not by
bdrv_block_device_info(), which is where BlockDeviceInfo is actually
created.

Anyone calling bdrv_block_device_info() directly will get a null image
field. As a consequence of this, the HMP command 'info block -n -v'
crashes QEMU.

This patch moves the code that fills in that field from
bdrv_query_info() to bdrv_block_device_info().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 1429271563-3765-1-git-send-email-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
Stefan Weil 2c20fa2cc2 block/qapi: Fix Sparse warning
Sparse reports this warning:

block/qapi.c:417:47: warning:
 too long initializer-string for array of char(no space for nul char)

Replacing the string by an array of characters fixes this warning.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-03-19 11:11:55 +03:00
Francesco Romani e2462113b2 block: add event when disk usage exceeds threshold
Managing applications, like oVirt (http://www.ovirt.org), make extensive
use of thin-provisioned disk images.
To let the guest run smoothly and be not unnecessarily paused, oVirt sets
a disk usage threshold (so called 'high water mark') based on the occupation
of the device,  and automatically extends the image once the threshold
is reached or exceeded.

In order to detect the crossing of the threshold, oVirt has no choice but
aggressively polling the QEMU monitor using the query-blockstats command.
This lead to unnecessary system load, and is made even worse under scale:
deployments with hundreds of VMs are no longer rare.

To fix this, this patch adds:
* A new monitor command `block-set-write-threshold', to set a mark for
  a given block device.
* A new event `BLOCK_WRITE_THRESHOLD', to report if a block device
  usage exceeds the threshold.
* A new `write_threshold' field into the `BlockDeviceInfo' structure,
  to report the configured threshold.

This will allow the managing application to use smarter and more
efficient monitoring, greatly reducing the need of polling.

[Updated qemu-iotests 067 output to add the new 'write_threshold'
property. --Stefan]
[Changed g_assert_false() to !g_assert() to fix the build on older glib
versions. --Kevin]

Signed-off-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1421068273-692-1-git-send-email-fromani@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06 17:24:21 +01:00
Peter Lieven f4564d53c6 block: add accounting for merged requests
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-02-06 17:24:21 +01:00
Jeff Cody 9a29e18f7d block: update string sizes for filename,backing_file,exact_filename
The string field entries 'filename', 'backing_file', and
'exact_filename' in the BlockDriverState struct are defined as 1024
bytes.

However, many places that use these values accept a maximum of PATH_MAX
bytes, so we have a mixture of 1024 byte and PATH_MAX byte allocations.
This patch makes the BlockDriverStruct field string sizes match usage.

This patch also does a few fixes related to the size that needs to
happen now:

    * the block qapi driver is updated to use PATH_MAX bytes
    * the qcow and qcow2 drivers have an additional safety check
    * the block vvfat driver is updated to use PATH_MAX bytes
      for the size of backing_file, for systems where PATH_MAX is < 1024
      bytes.
    * qemu-img uses PATH_MAX rather than 1024.  These instances were not
      changed to be dynamically allocated, however, as the extra
      temporary 3K in stack usage for qemu-img does not seem worrisome.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23 18:17:06 +01:00
Jeff Cody 564d64bdde block: qapi - move string allocation from stack to the heap
Rather than declaring 'backing_filename2' on the stack in
bdrv_query_image_info(), dynamically allocate it on the heap.

Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-23 18:17:06 +01:00
Max Reitz 9f07429e88 block: JSON filenames and relative backing files
When using a relative backing file name, qemu needs to know the
directory of the top image file. For JSON filenames, such a directory
cannot be easily determined (e.g. how do you determine the directory of
a qcow2 BDS directly on top of a quorum BDS?). Therefore, do not allow
relative filenames for the backing file of BDSs only having a JSON
filename.

Furthermore, BDS::exact_filename should be used whenever possible. If
BDS::filename is not equal to BDS::exact_filename, the former will
always be a JSON object.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-01-13 11:47:56 +00:00
Kevin Wolf 9e193c5a65 block/qapi: Add cache information to query-block
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2014-12-10 10:31:09 +01:00
Fam Zheng f71eaa74c0 qmp: Add optional switch "query-nodes" in query-blockstats
This bool option will allow query all the node names. It iterates all
the BDSes that are assigned a name, also in this case don't query up the
backing chain.

Signed-off-by: Fam Zheng <famz@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 10:25:29 +01:00
Fam Zheng 4875a77950 block: Include "node-name" if present in query-blockstats
Node name is a better identifier of BDS.

We will want to query statistics of a BDS node buried in the BDS graph,
so reporting the node's name if there is one will do the trick.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-12-10 10:25:29 +01:00
Kevin Wolf 24bf10dac3 Revert "qemu-img info: show nocow info"
This reverts commit 000c4dfff4.

The main reason for reverting this commit before the 2.2 release is that
it adds a QAPI interface that we don't want to keep: The 'nocow' flag
doesn't generally make sense for block nodes, but only for the raw-posix
driver. It should therefore be part of ImageInfoSpecific rather than
ImageInfo.

The commit contains more problems, but unlike the API stability issue
they wouldn't justify reverting it.

Conflicts:
	block/qapi.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-11-24 13:52:10 +01:00
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 d829a2115f block/qapi: Convert qmp_query_block() to BlockBackend
Much more command code needs conversion.  I start with this one
because it's using bdrv_dev_* functions, which I'm about to lift into
BlockBackend.

While there, give bdrv_query_info() internal linkage.

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 bfb197e0d9 block: Eliminate BlockDriverState member device_name[]
device_name[] can become non-empty only in bdrv_new_root() and
bdrv_move_feature_fields().  The latter is used only to undo damage
done by bdrv_swap().  The former is called only by blk_new_with_bs().
Therefore, when a BlockDriverState's device_name[] is non-empty, then
it's been created with a BlockBackend, and vice versa.  Furthermore,
blk_new_with_bs() keeps the two names equal.

Therefore, device_name[] is redundant.  Eliminate 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
Benoît Canet 28298fd3d9 block: rename BlockAcctType members to start with BLOCK_ instead of BDRV_
The middle term goal is to move the BlockAcctStats structure in the device models.
(Capturing I/O accounting statistics in the device models is good for billing)
This patch make a small step in this direction by removing a reference to BDRV.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Keith Busch <keith.busch@intel.com>
CC: Anthony Liguori <aliguori@amazon.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: John Snow <jsnow@redhat.com>
CC: Richard Henderson <rth@twiddle.net>
CC: Markus Armbruster <armbru@redhat.com>
CC: Alexander Graf <agraf@suse.de>i

Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10 10:41:29 +02:00
Benoît Canet 0ddd0ad96a block: Extract the BlockAcctStats structure
Extract the block accounting statistics into a structure so the block device
models can hold them in the future.

CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Eric Blake <eblake@redhat.com>

Signed-off-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-09-10 10:41:29 +02:00
Chunyan Liu 000c4dfff4 qemu-img info: show nocow info
Add nocow info in 'qemu-img info' output to show whether the file
currently has NOCOW flag set or not.

Signed-off-by: Chunyan Liu <cyliu@suse.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15 15:07:14 +02:00
Markus Armbruster 52bf1e722d block: Avoid bdrv_get_geometry() where errors should be detected
bdrv_get_geometry() hides errors.  Use bdrv_nb_sectors() or
bdrv_getlength() instead where that's obviously inappropriate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-08-15 15:07:13 +02:00
Stefan Hajnoczi 13344f3a17 block: acquire AioContext in qmp_query_blockstats()
Make query-blockstats safe for dataplane by acquiring the
BlockDriverState's AioContext.  This ensures that the dataplane IOThread
and the main loop's monitor code do not race.

Note the assumption that acquiring the drive's BDS AioContext also
protects ->file and ->backing_hd.  This assumption is made by other
aio_context_acquire() callers too.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-27 18:20:29 +02:00
Stefan Hajnoczi ac46821f2c block: make bdrv_query_stats() static
This function is only called from block/qapi.c.  There is no need to
keep it public.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-06-27 18:19:57 +02:00
Markus Armbruster f25391c2a6 block/qapi: Plug memory leak in dump_qobject() case QTYPE_QERROR
Introduced in commit a8d8ecb.  Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-30 14:26:54 +02:00
Peter Lieven 465bee1da8 block: optimize zero writes with bdrv_write_zeroes
this patch tries to optimize zero write requests
by automatically using bdrv_write_zeroes if it is
supported by the format.

This significantly speeds up file system initialization and
should speed zero write test used to test backend storage
performance.

I ran the following 2 tests on my internal SSD with a
50G QCOW2 container and on an attached iSCSI storage.

a) mkfs.ext4 -E lazy_itable_init=0,lazy_journal_init=0 /dev/vdX

QCOW2         [off]     [on]     [unmap]
-----
runtime:       14secs    1.1secs  1.1secs
filesize:      937M      18M      18M

iSCSI         [off]     [on]     [unmap]
----
runtime:       9.3s      0.9s     0.9s

b) dd if=/dev/zero of=/dev/vdX bs=1M oflag=direct

QCOW2         [off]     [on]     [unmap]
-----
runtime:       246secs   18secs   18secs
filesize:      51G       192K     192K
throughput:    203M/s    2.3G/s   2.3G/s

iSCSI*        [off]     [on]     [unmap]
----
runtime:       8mins     45secs   33secs
throughput:    106M/s    1.2G/s   1.6G/s
allocated:     100%      100%     0%

* The storage was connected via an 1Gbit interface.
  It seems to internally handle writing zeroes
  via WRITESAME16 very fast.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-05-19 13:42:27 +02:00