Commit Graph

127 Commits

Author SHA1 Message Date
Markus Armbruster
77ed971b9d block/file-posix: Fix check_cache_dropped() error handling
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

check_cache_dropped() calls error_setg() in a loop.  It fails to break
the loop in one instance.  If a subsequent iteration error_setg()s
again, it trips error_setv()'s assertion.

Fix it to break the loop.

Fixes: 31be8a2a97
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200422130719.28225-3-armbru@redhat.com>
2020-04-29 08:01:52 +02:00
Maxim Levitsky
5a5e7f8cd8 block: trickle down the fallback image creation function use to the block drivers
Instead of checking the .bdrv_co_create_opts to see if we need the
fallback, just implement the .bdrv_co_create_opts in the drivers that
need it.

This way we don't break various places that need to know if the
underlying protocol/format really supports image creation, and this way
we still allow some drivers to not support image creation.

Fixes: fd17146cd9
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1816007

Note that technically this driver reverts the image creation fallback
for the vxhs driver since I don't have a means to test it, and IMHO it
is better to leave it not supported as it was prior to generic image
creation patches.

Also drop iscsi_create_opts which was left accidentally.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-3-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
[mreitz: Fixed alignment, and moved bdrv_co_create_opts_simple() and
         bdrv_create_opts_simple from block.h into block_int.h]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26 14:44:33 +01:00
Maxim Levitsky
b92902dfea block: pass BlockDriver reference to the .bdrv_co_create
This will allow the reuse of a single generic .bdrv_co_create
implementation for several drivers.
No functional changes.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200326011218.29230-2-mlevitsk@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-03-26 14:44:33 +01:00
Daniel Henrique Barboza
9bffae14df block: introducing 'bdrv_co_delete_file' interface
Adding to Block Drivers the capability of being able to clean up
its created files can be useful in certain situations. For the
LUKS driver, for instance, a failure in one of its authentication
steps can leave files in the host that weren't there before.

This patch adds the 'bdrv_co_delete_file' interface to block
drivers and add it to the 'file' driver in file-posix.c. The
implementation is given by 'raw_co_delete_file'.

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20200130213907.2830642-2-danielhb413@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11 15:54:38 +01:00
Chen Qun
76e91cda07 block/file-posix: Remove redundant statement in raw_handle_perm_lock()
Clang static code analyzer show warning:
  block/file-posix.c:891:9: warning: Value stored to 'op' is never read
        op = RAW_PL_ABORT;
        ^    ~~~~~~~~~~~~

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200302130715.29440-5-kuhn.chenqun@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-03-09 15:59:31 +01:00
Max Reitz
87ca3b8fa6 file-posix: Drop hdev_co_create_opts()
The generic fallback implementation effectively does the same.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200122164532.178040-4-mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2020-02-20 16:43:42 +01:00
Aarushi Mehta
c644751069 block/file-posix.c: extend to use io_uring
Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200120141858.587874-9-stefanha@redhat.com
Message-Id: <20200120141858.587874-9-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30 20:59:42 +00:00
Paolo Bonzini
18fbd0dec7 block/io: wait for serialising requests when a request becomes serialising
Marking without waiting would not result in actual serialising behavior.
Thus, make a call bdrv_mark_request_serialising sufficient for
serialisation to happen.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1578495356-46219-3-git-send-email-pbonzini@redhat.com
Message-Id: <1578495356-46219-3-git-send-email-pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-01-30 20:59:41 +00:00
Markus Armbruster
cb09104ea8 block/file-posix: Fix laio_init() error handling crash bug
raw_aio_attach_aio_context() passes uninitialized Error *local_err by
reference to laio_init() via aio_setup_linux_aio().  When laio_init()
fails, it passes it on to error_setg_errno(), tripping error_setv()'s
assertion unless @local_err is null by dumb luck.

Fix by initializing @local_err properly.

Fixes: ed6e216171
Cc: Nishanth Aravamudan <naravamudan@digitalocean.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191130194240.10517-4-armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2019-12-02 16:14:41 +01:00
Max Reitz
292d06b925 block/file-posix: Let post-EOF fallocate serialize
The XFS kernel driver has a bug that may cause data corruption for qcow2
images as of qemu commit c8bb23cbdb.  We can work around it by
treating post-EOF fallocates as serializing up until infinity (INT64_MAX
in practice).

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20191101152510.11719-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-11-04 09:33:51 +01:00
Peter Maydell
aaffb85335 Block patches for softfreeze:
- iotest patches
 - Improve performance of the mirror block job in write-blocking mode
 - Limit memory usage for the backup block job
 - Add discard and write-zeroes support to the NVMe host block driver
 - Fix a bug in the mirror job
 - Prevent the qcow2 driver from creating technically non-compliant qcow2
   v3 images (where there is not enough extra data for snapshot table
   entries)
 - Allow callers of bdrv_truncate() (etc.) to determine whether the file
   must be resized to the exact given size or whether it is OK for block
   devices not to shrink
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Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-10-28' into staging

Block patches for softfreeze:
- iotest patches
- Improve performance of the mirror block job in write-blocking mode
- Limit memory usage for the backup block job
- Add discard and write-zeroes support to the NVMe host block driver
- Fix a bug in the mirror job
- Prevent the qcow2 driver from creating technically non-compliant qcow2
  v3 images (where there is not enough extra data for snapshot table
  entries)
- Allow callers of bdrv_truncate() (etc.) to determine whether the file
  must be resized to the exact given size or whether it is OK for block
  devices not to shrink

# gpg: Signature made Mon 28 Oct 2019 12:13:53 GMT
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-10-28: (69 commits)
  qemu-iotests: restrict 264 to qcow2 only
  Revert "qemu-img: Check post-truncation size"
  block: Pass truncate exact=true where reasonable
  block: Let format drivers pass @exact
  block: Evaluate @exact in protocol drivers
  block: Add @exact parameter to bdrv_co_truncate()
  block: Do not truncate file node when formatting
  block/cor: Drop cor_co_truncate()
  block: Handle filter truncation like native impl.
  iotests: Test qcow2's snapshot table handling
  iotests: Add peek_file* functions
  qcow2: Fix v3 snapshot table entry compliancy
  qcow2: Repair snapshot table with too many entries
  qcow2: Fix overly long snapshot tables
  qcow2: Keep track of the snapshot table length
  qcow2: Fix broken snapshot table entries
  qcow2: Add qcow2_check_fix_snapshot_table()
  qcow2: Separate qcow2_check_read_snapshot_table()
  qcow2: Write v3-compliant snapshot list on upgrade
  qcow2: Put qcow2_upgrade() into its own function
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-28 14:40:01 +00:00
Max Reitz
82325ae5f2 block: Evaluate @exact in protocol drivers
We have two protocol drivers that return success when trying to shrink a
block device even though they cannot shrink it.  This behavior is now
only allowed with exact=false, so they should return an error with
exact=true.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-6-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:05:24 +01:00
Max Reitz
c80d8b06cf block: Add @exact parameter to bdrv_co_truncate()
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk.  Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.

This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around.  All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior.  Future patches take care
of that.

Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-28 12:00:07 +01:00
Wei Yang
038adc2f58 core: replace getpagesize() with qemu_real_host_page_size
There are three page size in qemu:

  real host page size
  host page size
  target page size

All of them have dedicate variable to represent. For the last two, we
use the same form in the whole qemu project, while for the first one we
use two forms: qemu_real_host_page_size and getpagesize().

qemu_real_host_page_size is defined to be a replacement of
getpagesize(), so let it serve the role.

[Note] Not fully tested for some arch or device.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20191013021145.16011-3-richardw.yang@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-26 15:38:06 +02:00
Anton Nefedov
d924559953 qapi: query-blockstat: add driver specific file-posix stats
A block driver can provide a callback to report driver-specific
statistics.

file-posix driver now reports discard statistics

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20190923121737.83281-10-anton.nefedov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10 10:56:18 +02:00
Anton Nefedov
1c45036636 file-posix: account discard operations
This will help to identify how many of the user-issued discard operations
(accounted on a device level) have actually suceeded down on the host file
(even though the numbers will not be exactly the same if non-raw format
driver is used (e.g. qcow2 sending metadata discards)).

Note that these numbers will not include discards triggered by
write-zeroes + MAY_UNMAP calls.

Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190923121737.83281-9-anton.nefedov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10 10:56:18 +02:00
Kevin Wolf
effecce6bc file-posix: Fix has_write_zeroes after NO_FALLBACK
If QEMU_AIO_NO_FALLBACK is given, we always return failure and don't
even try to use the BLKZEROOUT ioctl. In this failure case, we shouldn't
disable has_write_zeroes because we didn't learn anything about the
ioctl. The next request might not set QEMU_AIO_NO_FALLBACK and we can
still use the ioctl then.

Fixes: 738301e117
Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-09-10 08:58:43 +02:00
Max Reitz
b2c6f23f4a block/file-posix: Reduce xfsctl() use
This patch removes xfs_write_zeroes() and xfs_discard().  Both functions
have been added just before the same feature was present through
fallocate():

- fallocate() has supported PUNCH_HOLE for XFS since Linux 2.6.38 (March
  2011); xfs_discard() was added in December 2010.

- fallocate() has supported ZERO_RANGE for XFS since Linux 3.15 (June
  2014); xfs_write_zeroes() was added in November 2013.

Nowadays, all systems that qemu runs on should support both fallocate()
features (RHEL 7's kernel does).

xfsctl() is still useful for getting the request alignment for O_DIRECT,
so this patch does not remove our dependency on it completely.

Note that xfs_write_zeroes() had a bug: It calls ftruncate() when the
file is shorter than the specified range (because ZERO_RANGE does not
increase the file length).  ftruncate() may yield and then discard data
that parallel write requests have written past the EOF in the meantime.
Dropping the function altogether fixes the bug.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Fixes: 50ba5b2d99
Reported-by: Lukáš Doktor <ldoktor@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Tested-by: Stefano Garzarella <sgarzare@redhat.com>
Tested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-09-10 08:58:43 +02:00
Andrey Shinkevich
294682cc3a block: workaround for unaligned byte range in fallocate()
Revert the commit 118f99442d 'block/io.c: fix for the allocation failure'
and use better error handling for file systems that do not support
fallocate() for an unaligned byte range. Allow falling back to pwrite
in case fallocate() returns EINVAL.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-Id: <1566913973-15490-1-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-09-05 16:01:31 -05:00
Stefan Hajnoczi
236094c738 file-posix: fix request_alignment typo
Fixes: a6b257a08e
       ("file-posix: Handle undetectable alignment")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190827101328.4062-1-stefanha@redhat.com
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-03 14:55:35 +02:00
Nir Soffer
3a20013fbb block: posix: Always allocate the first block
When creating an image with preallocation "off" or "falloc", the first
block of the image is typically not allocated. When using Gluster
storage backed by XFS filesystem, reading this block using direct I/O
succeeds regardless of request length, fooling alignment detection.

In this case we fallback to a safe value (4096) instead of the optimal
value (512), which may lead to unneeded data copying when aligning
requests.  Allocating the first block avoids the fallback.

Since we allocate the first block even with preallocation=off, we no
longer create images with zero disk size:

    $ ./qemu-img create -f raw test.raw 1g
    Formatting 'test.raw', fmt=raw size=1073741824

    $ ls -lhs test.raw
    4.0K -rw-r--r--. 1 nsoffer nsoffer 1.0G Aug 16 23:48 test.raw

And converting the image requires additional cluster:

    $ ./qemu-img measure -f raw -O qcow2 test.raw
    required size: 458752
    fully allocated size: 1074135040

When using format like vmdk with multiple files per image, we allocate
one block per file:

    $ ./qemu-img create -f vmdk -o subformat=twoGbMaxExtentFlat test.vmdk 4g
    Formatting 'test.vmdk', fmt=vmdk size=4294967296 compat6=off hwversion=undefined subformat=twoGbMaxExtentFlat

    $ ls -lhs test*.vmdk
    4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f001.vmdk
    4.0K -rw-r--r--. 1 nsoffer nsoffer 2.0G Aug 27 03:23 test-f002.vmdk
    4.0K -rw-r--r--. 1 nsoffer nsoffer  353 Aug 27 03:23 test.vmdk

I did quick performance test for copying disks with qemu-img convert to
new raw target image to Gluster storage with sector size of 512 bytes:

    for i in $(seq 10); do
        rm -f dst.raw
        sleep 10
        time ./qemu-img convert -f raw -O raw -t none -T none src.raw dst.raw
    done

Here is a table comparing the total time spent:

Type    Before(s)   After(s)    Diff(%)
---------------------------------------
real      530.028    469.123      -11.4
user       17.204     10.768      -37.4
sys        17.881      7.011      -60.7

We can see very clear improvement in CPU usage.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827010528.8818-2-nsoffer@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-03 14:55:35 +02:00
Max Reitz
1dcaf52760 block: Implement .bdrv_has_zero_init_truncate()
We need to implement .bdrv_has_zero_init_truncate() for every block
driver that supports truncation and has a .bdrv_has_zero_init()
implementation.

Implement it the same way each driver implements .bdrv_has_zero_init().
This is at least not any more unsafe than what we had before.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
Paolo Bonzini
f6fc1e30cf block: fix NetBSD qemu-iotests failure
Opening a block device on NetBSD has an additional step compared to other OSes,
corresponding to raw_normalize_devicepath.  The error message in that function
is slightly different from that in raw_open_common and this was causing spurious
failures in qemu-iotests.  However, in general it is not important to know what
exact step was failing, for example in the qemu-iotests case the error message
contains the fairly unequivocal "No such file or directory" text from strerror.
We can thus fix the failures by standardizing on a single error message for
both raw_open_common and raw_normalize_devicepath; in fact, we can even
use error_setg_file_open to make sure the error message is the same as in
the rest of QEMU.

Message-Id: <20190725095920.28419-1-pbonzini@redhat.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-08-17 09:02:59 +02:00
Nir Soffer
a6b257a08e file-posix: Handle undetectable alignment
In some cases buf_align or request_alignment cannot be detected:

1. With Gluster, buf_align cannot be detected since the actual I/O is
   done on Gluster server, and qemu buffer alignment does not matter.
   Since we don't have alignment requirement, buf_align=1 is the best
   value.

2. With local XFS filesystem, buf_align cannot be detected if reading
   from unallocated area. In this we must align the buffer, but we don't
   know what is the correct size. Using the wrong alignment results in
   I/O error.

3. With Gluster backed by XFS, request_alignment cannot be detected if
   reading from unallocated area. In this case we need to use the
   correct alignment, and failing to do so results in I/O errors.

4. With NFS, the server does not use direct I/O, so both buf_align cannot
   be detected. In this case we don't need any alignment so we can use
   buf_align=1 and request_alignment=1.

These cases seems to work when storage sector size is 512 bytes, because
the current code starts checking align=512. If the check succeeds
because alignment cannot be detected we use 512. But this does not work
for storage with 4k sector size.

To determine if we can detect the alignment, we probe first with
align=1. If probing succeeds, maybe there are no alignment requirement
(cases 1, 4) or we are probing unallocated area (cases 2, 3). Since we
don't have any way to tell, we treat this as undetectable alignment. If
probing with align=1 fails with EINVAL, but probing with one of the
expected alignments succeeds, we know that we found a working alignment.

Practically the alignment requirements are the same for buffer
alignment, buffer length, and offset in file. So in case we cannot
detect buf_align, we can use request alignment. If we cannot detect
request alignment, we can fallback to a safe value. To use this logic,
we probe first request alignment instead of buf_align.

Here is a table showing the behaviour with current code (the value in
parenthesis is the optimal value).

Case    Sector    buf_align (opt)   request_alignment (opt)     result
======================================================================
1       512       512   (1)          512   (512)                 OK
1       4096      512   (1)          4096  (4096)                FAIL
----------------------------------------------------------------------
2       512       512   (512)        512   (512)                 OK
2       4096      512   (4096)       4096  (4096)                FAIL
----------------------------------------------------------------------
3       512       512   (1)          512   (512)                 OK
3       4096      512   (1)          512   (4096)                FAIL
----------------------------------------------------------------------
4       512       512   (1)          512   (1)                   OK
4       4096      512   (1)          512   (1)                   OK

Same cases with this change:

Case    Sector    buf_align (opt)   request_alignment (opt)     result
======================================================================
1       512       512   (1)          512   (512)                 OK
1       4096      4096  (1)          4096  (4096)                OK
----------------------------------------------------------------------
2       512       512   (512)        512   (512)                 OK
2       4096      4096  (4096)       4096  (4096)                OK
----------------------------------------------------------------------
3       512       4096  (1)          4096  (512)                 OK
3       4096      4096  (1)          4096  (4096)                OK
----------------------------------------------------------------------
4       512       4096  (1)          4096  (1)                   OK
4       4096      4096  (1)          4096  (1)                   OK

I tested that provisioning VMs and copying disks on local XFS and
Gluster with 4k bytes sector size work now, resolving bugs [1],[2].
I tested also on XFS, NFS, Gluster with 512 bytes sector size.

[1] https://bugzilla.redhat.com/1737256
[2] https://bugzilla.redhat.com/1738657

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-08-16 11:29:11 +02:00
Maxim Levitsky
867eccfed8 file-posix: Use max transfer length/segment count only for SCSI passthrough
Regular kernel block devices (/dev/sda*, /dev/nvme*, etc) don't have
max segment size/max segment count hardware requirements exposed
to the userspace, but rather the kernel block layer
takes care to split the incoming requests that
violate these requirements.

Allowing the kernel to do the splitting allows qemu to avoid
various overheads that arise otherwise from this.

This is especially visible in nbd server,
exposing as a raw file, a mostly empty qcow2 image over the net.
In this case most of the reads by the remote user
won't even hit the underlying kernel block device,
and therefore most of the  overhead will be in the
nbd traffic which increases significantly with lower max transfer size.

In addition to that even for local block device
access the peformance improves a bit due to less
traffic between qemu and the kernel when large
transfer sizes are used (e.g for image conversion)

More info can be found at:
https://bugzilla.redhat.com/show_bug.cgi?id=1647104

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-12 15:42:23 +02:00
Max Reitz
094e363944 file-posix: Update open_flags in raw_set_perm()
raw_check_perm() + raw_set_perm() can change the flags associated with
the current FD.  If so, we have to update BDRVRawState.open_flags
accordingly.  Otherwise, we may keep reopening the FD even though the
current one already has the correct flags.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Stefano Garzarella
abea00533f block/file-posix: update .help of BLOCK_OPT_PREALLOC option
Show 'falloc' among the allowed values of 'preallocation'
option, only when it is supported (if defined CONFIG_POSIX_FALLOCATE)

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190524075848.23781-3-sgarzare@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-06-12 18:31:46 +02:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Max Reitz
9c3db310ff block/file-posix: Unaligned O_DIRECT block-status
Currently, qemu crashes whenever someone queries the block status of an
unaligned image tail of an O_DIRECT image:
$ echo > foo
$ qemu-img map --image-opts driver=file,filename=foo,cache.direct=on
Offset          Length          Mapped to       File
qemu-img: block/io.c:2093: bdrv_co_block_status: Assertion `*pnum &&
QEMU_IS_ALIGNED(*pnum, align) && align > offset - aligned_offset'
failed.

This is because bdrv_co_block_status() checks that the result returned
by the driver's implementation is aligned to the request_alignment, but
file-posix can fail to do so, which is actually mentioned in a comment
there: "[...] possibly including a partial sector at EOF".

Fix this by rounding up those partial sectors.

There are two possible alternative fixes:
(1) We could refuse to open unaligned image files with O_DIRECT
    altogether.  That sounds reasonable until you realize that qcow2
    does necessarily not fill up its metadata clusters, and that nobody
    runs qemu-img create with O_DIRECT.  Therefore, unpreallocated qcow2
    files usually have an unaligned image tail.

(2) bdrv_co_block_status() could ignore unaligned tails.  It actually
    throws away everything past the EOF already, so that sounds
    reasonable.
    Unfortunately, the block layer knows file lengths only with a
    granularity of BDRV_SECTOR_SIZE, so bdrv_co_block_status() usually
    would have to guess whether its file length information is inexact
    or whether the driver is broken.

Fixing what raw_co_block_status() returns is the safest thing to do.

There seems to be no other block driver that sets request_alignment and
does not make sure that it always returns aligned values.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20 17:08:57 +02:00
Max Reitz
50ba5b2d99 block/file-posix: Truncate in xfs_write_zeroes()
XFS_IOC_ZERO_RANGE does not increase the file length:
$ touch foo
$ xfs_io -c 'zero 0 65536' foo
$ stat -c "size=%s, blocks=%b" foo
size=0, blocks=128

We do want writes beyond the EOF to automatically increase the file
length, however.  This is evidenced by the fact that iotest 061 is
broken on XFS since qcow2's check implementation checks for blocks
beyond the EOF.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20 17:08:56 +02:00
Vladimir Sementsov-Ogievskiy
696aaaed57 block/file-posix: do not fail on unlock bytes
bdrv_replace_child() calls bdrv_check_perm() with error_abort on
loosening permissions. However file-locking operations may fail even
in this case, for example on NFS. And this leads to Qemu crash.

Let's avoid such errors. Note, that we ignore such things anyway on
permission update commit and abort.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-02 12:04:44 +02:00
Kevin Wolf
738301e117 file-posix: Support BDRV_REQ_NO_FALLBACK for zero writes
We know that the kernel implements a slow fallback code path for
BLKZEROOUT, so if BDRV_REQ_NO_FALLBACK is given, we shouldn't call it.
The other operations we call in the context of .bdrv_co_pwrite_zeroes
should usually be quick, so no modification should be needed for them.
If we ever notice that there are additional problematic cases, we can
still make these conditional as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26 11:37:51 +01:00
Peter Maydell
dbbc277510 Pull request
* Add 'drop-cache=on|off' option to file-posix.c.  The default is on.
    Disabling the option fixes a QEMU 3.0.0 performance regression when live
    migrating on the same host with cache.direct=off.
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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Pull request

 * Add 'drop-cache=on|off' option to file-posix.c.  The default is on.
   Disabling the option fixes a QEMU 3.0.0 performance regression when live
   migrating on the same host with cache.direct=off.

# gpg: Signature made Wed 13 Mar 2019 11:07:48 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  file-posix: add drop-cache=on|off option

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-03-14 09:34:51 +00:00
Stefan Hajnoczi
f357fcd890 file-posix: add drop-cache=on|off option
Commit dd577a26ff ("block/file-posix:
implement bdrv_co_invalidate_cache() on Linux") introduced page cache
invalidation so that cache.direct=off live migration is safe on Linux.

The invalidation takes a significant amount of time when the file is
large and present in the page cache.  Normally this is not the case for
cross-host live migration but it can happen when migrating between QEMU
processes on the same host.

On same-host migration we don't need to invalidate pages for correctness
anyway, so an option to skip page cache invalidation is useful.  I
investigated optimizing invalidation and detecting same-host migration,
but both are hard to achieve so a user-visible option will suffice.

As a bonus this option means that the cache invalidation feature will
now be detectable by libvirt via QMP schema introspection.

Suggested-by: Neil Skrypuch <neil@tembosocial.com>
Tested-by: Neil Skrypuch <neil@tembosocial.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190307164941.3322-1-stefanha@redhat.com
Message-Id: <20190307164941.3322-1-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-13 10:54:55 +00:00
Alberto Garcia
8a2ce0bc1e block: Add a 'mutable_opts' field to BlockDriver
If we reopen a BlockDriverState and there is an option that is present
in bs->options but missing from the new set of options then we have to
return an error unless the driver is able to reset it to its default
value.

This patch adds a new 'mutable_opts' field to BlockDriver. This is
a list of runtime options that can be modified during reopen. If an
option in this list is unspecified on reopen then it must be reset (or
return an error).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Kevin Wolf
23dece19da file-posix: Make auto-read-only dynamic
Until now, with auto-read-only=on we tried to open the file read-write
first and if that failed, read-only was tried. This is actually not good
enough for libvirt, which gives QEMU SELinux permissions for read-write
only as soon as it actually intends to write to the image. So we need to
be able to switch between read-only and read-write at runtime.

This patch makes auto-read-only dynamic, i.e. the file is opened
read-only as long as no user of the node has requested write
permissions, but it is automatically reopened read-write as soon as the
first writer is attached. Conversely, if the last writer goes away, the
file is reopened read-only again.

bs->read_only is no longer set for auto-read-only=on files even if the
file descriptor is opened read-only because it will be transparently
upgraded as soon as a writer is attached. This changes the output of
qemu-iotests 232.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Kevin Wolf
6ceabe6f77 file-posix: Prepare permission code for fd switching
In order to be able to dynamically reopen the file read-only or
read-write, depending on the users that are attached, we need to be able
to switch to a different file descriptor during the permission change.

This interacts with reopen, which also creates a new file descriptor and
performs permission changes internally. In this case, the permission
change code must reuse the reopen file descriptor instead of creating a
third one.

In turn, reopen can drop its code to copy file locks to the new file
descriptor because that is now done when applying the new permissions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Kevin Wolf
a6aeca0ca5 file-posix: Lock new fd in raw_reopen_prepare()
There is no reason why we can take locks on the new file descriptor only
in raw_reopen_commit() where error handling isn't possible any more.
Instead, we can already do this in raw_reopen_prepare().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Kevin Wolf
e0c9cf3a48 file-posix: Store BDRVRawState.reopen_state during reopen
We'll want to access the file descriptor in the reopen_state while
processing permission changes in the context of the repoen.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Kevin Wolf
5cec287025 file-posix: Factor out raw_reconfigure_getfd()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Laurent Vivier
4f7d28d738 block/file-posix: Convert from DPRINTF() macro to trace events
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181213162727.17438-4-lvivier@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Paolo Bonzini
7d37435bd5 avoid TABs in files that only contain a few
Most files that have TABs only contain a handful of them.  Change
them to spaces so that we don't confuse people.

disas, standard-headers, linux-headers and libdecnumber are imported
from other projects and probably should be exempted from the check.
Outside those, after this patch the following files still contain both
8-space and TAB sequences at the beginning of the line.  Many of them
have a majority of TABs, or were initially committed with all tabs.

    bsd-user/i386/target_syscall.h
    bsd-user/x86_64/target_syscall.h
    crypto/aes.c
    hw/audio/fmopl.c
    hw/audio/fmopl.h
    hw/block/tc58128.c
    hw/display/cirrus_vga.c
    hw/display/xenfb.c
    hw/dma/etraxfs_dma.c
    hw/intc/sh_intc.c
    hw/misc/mst_fpga.c
    hw/net/pcnet.c
    hw/sh4/sh7750.c
    hw/timer/m48t59.c
    hw/timer/sh_timer.c
    include/crypto/aes.h
    include/disas/bfd.h
    include/hw/sh4/sh.h
    libdecnumber/decNumber.c
    linux-headers/asm-generic/unistd.h
    linux-headers/linux/kvm.h
    linux-user/alpha/target_syscall.h
    linux-user/arm/nwfpe/double_cpdo.c
    linux-user/arm/nwfpe/fpa11_cpdt.c
    linux-user/arm/nwfpe/fpa11_cprt.c
    linux-user/arm/nwfpe/fpa11.h
    linux-user/flat.h
    linux-user/flatload.c
    linux-user/i386/target_syscall.h
    linux-user/ppc/target_syscall.h
    linux-user/sparc/target_syscall.h
    linux-user/syscall.c
    linux-user/syscall_defs.h
    linux-user/x86_64/target_syscall.h
    slirp/cksum.c
    slirp/if.c
    slirp/ip.h
    slirp/ip_icmp.c
    slirp/ip_icmp.h
    slirp/ip_input.c
    slirp/ip_output.c
    slirp/mbuf.c
    slirp/misc.c
    slirp/sbuf.c
    slirp/socket.c
    slirp/socket.h
    slirp/tcp_input.c
    slirp/tcpip.h
    slirp/tcp_output.c
    slirp/tcp_subr.c
    slirp/tcp_timer.c
    slirp/tftp.c
    slirp/udp.c
    slirp/udp.h
    target/cris/cpu.h
    target/cris/mmu.c
    target/cris/op_helper.c
    target/sh4/helper.c
    target/sh4/op_helper.c
    target/sh4/translate.c
    tcg/sparc/tcg-target.inc.c
    tests/tcg/cris/check_addo.c
    tests/tcg/cris/check_moveq.c
    tests/tcg/cris/check_swap.c
    tests/tcg/multiarch/test-mmap.c
    ui/vnc-enc-hextile-template.h
    ui/vnc-enc-zywrle.h
    util/envlist.c
    util/readline.c

The following have only TABs:

    bsd-user/i386/target_signal.h
    bsd-user/sparc64/target_signal.h
    bsd-user/sparc64/target_syscall.h
    bsd-user/sparc/target_signal.h
    bsd-user/sparc/target_syscall.h
    bsd-user/x86_64/target_signal.h
    crypto/desrfb.c
    hw/audio/intel-hda-defs.h
    hw/core/uboot_image.h
    hw/sh4/sh7750_regnames.c
    hw/sh4/sh7750_regs.h
    include/hw/cris/etraxfs_dma.h
    linux-user/alpha/termbits.h
    linux-user/arm/nwfpe/fpopcode.h
    linux-user/arm/nwfpe/fpsr.h
    linux-user/arm/syscall_nr.h
    linux-user/arm/target_signal.h
    linux-user/cris/target_signal.h
    linux-user/i386/target_signal.h
    linux-user/linux_loop.h
    linux-user/m68k/target_signal.h
    linux-user/microblaze/target_signal.h
    linux-user/mips64/target_signal.h
    linux-user/mips/target_signal.h
    linux-user/mips/target_syscall.h
    linux-user/mips/termbits.h
    linux-user/ppc/target_signal.h
    linux-user/sh4/target_signal.h
    linux-user/sh4/termbits.h
    linux-user/sparc64/target_syscall.h
    linux-user/sparc/target_signal.h
    linux-user/x86_64/target_signal.h
    linux-user/x86_64/termbits.h
    pc-bios/optionrom/optionrom.h
    slirp/mbuf.h
    slirp/misc.h
    slirp/sbuf.h
    slirp/tcp.h
    slirp/tcp_timer.h
    slirp/tcp_var.h
    target/i386/svm.h
    target/sparc/asi.h
    target/xtensa/core-dc232b/xtensa-modules.inc.c
    target/xtensa/core-dc233c/xtensa-modules.inc.c
    target/xtensa/core-de212/core-isa.h
    target/xtensa/core-de212/xtensa-modules.inc.c
    target/xtensa/core-fsf/xtensa-modules.inc.c
    target/xtensa/core-sample_controller/core-isa.h
    target/xtensa/core-sample_controller/xtensa-modules.inc.c
    target/xtensa/core-test_kc705_be/core-isa.h
    target/xtensa/core-test_kc705_be/xtensa-modules.inc.c
    tests/tcg/cris/check_abs.c
    tests/tcg/cris/check_addc.c
    tests/tcg/cris/check_addcm.c
    tests/tcg/cris/check_addoq.c
    tests/tcg/cris/check_bound.c
    tests/tcg/cris/check_ftag.c
    tests/tcg/cris/check_int64.c
    tests/tcg/cris/check_lz.c
    tests/tcg/cris/check_openpf5.c
    tests/tcg/cris/check_sigalrm.c
    tests/tcg/cris/crisutils.h
    tests/tcg/cris/sys.c
    tests/tcg/i386/test-i386-ssse3.c
    ui/vgafont.h

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181213223737.11793-3-pbonzini@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11 15:46:56 +01:00
Kevin Wolf
0342567115 file-posix: Avoid aio_worker() for QEMU_AIO_IOCTL
aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.

This was the last user of aio_worker(), so the function goes away now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:54:49 +01:00
Kevin Wolf
2f3a7ab39b file-posix: Switch to .bdrv_co_ioctl
No real reason to keep using the callback based mechanism here when the
rest of the file-posix driver is coroutine based. Changing it brings
ioctls more in line with how other request types work.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
c9db2b6489 file-posix: Remove paio_submit_co()
The function is not used any more, remove it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
999e6b69ce file-posix: Avoid aio_worker() for QEMU_AIO_READ/WRITE
aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
54c7ca1b81 file-posix: Move read/write operation logic out of aio_worker()
aio_worker() for reads and writes isn't boring enough yet. It still does
some postprocessing for handling short reads and turning the result into
the right return value.

However, there is no reason why handle_aiocb_rw() couldn't do the same,
and even without duplicating code between the read and write path. So
move the code there.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
06dc9bd571 file-posix: Avoid aio_worker() for QEMU_AIO_FLUSH
aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
46ee0f462b file-posix: Avoid aio_worker() for QEMU_AIO_DISCARD
aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00
Kevin Wolf
7154d8ae66 file-posix: Avoid aio_worker() for QEMU_AIO_WRITE_ZEROES
aio_worker() doesn't add anything interesting, it's only a useless
indirection. Call the handler function directly instead.

As we know that this handler function is only called from coroutine
context and the coroutine stays around until the worker thread finishes,
we can keep RawPosixAIOData on the stack.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:41 +01:00