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  1. 12 9月, 2011 7 次提交
  3. 06 9月, 2011 4 次提交
  5. 27 8月, 2011 1 次提交
  7. 26 8月, 2011 1 次提交
    • C
      block: explicit I/O accounting · a597e79c
      由 Christoph Hellwig 提交于 
      Decouple the I/O accounting from bdrv_aio_readv/writev/flush and
make the hardware models call directly into the accounting helpers.

This means:
 - we do not count internal requests from image formats in addition
   to guest originating I/O
 - we do not double count I/O ops if the device model handles it
   chunk wise
 - we only account I/O once it actuall is done
 - can extent I/O accounting to synchronous or coroutine I/O easily
 - implement I/O latency tracking easily (see the next patch)

I've conveted the existing device model callers to the new model,
device models that are using synchronous I/O and weren't accounted
before haven't been updated yet.  Also scsi hasn't been converted
to the end-to-end accounting as I want to defer that after the pending
scsi layer overhaul.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      a597e79c
  9. 23 8月, 2011 1 次提交
  11. 02 8月, 2011 1 次提交
    • K
      block: Add bdrv_co_readv/writev · da1fa91d
      由 Kevin Wolf 提交于 
      Add new block driver callbacks bdrv_co_readv/writev, which work on a
QEMUIOVector like bdrv_aio_*, but don't need a callback. The function may only
be called inside a coroutine, so a block driver implementing this interface can
yield instead of blocking during I/O.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      da1fa91d
  13. 01 8月, 2011 1 次提交
  15. 19 7月, 2011 1 次提交
  17. 15 6月, 2011 1 次提交
  19. 19 5月, 2011 1 次提交
  21. 07 4月, 2011 1 次提交
    • R
      Do not delete BlockDriverState when deleting the drive · d22b2f41
      由 Ryan Harper 提交于 
      When removing a drive from the host-side via drive_del we currently have
the following path:

drive_del
qemu_aio_flush()
bdrv_close()    // zaps bs->drv, which makes any subsequent I/O get
                // dropped.  Works as designed
drive_uninit()
bdrv_delete()   // frees the bs.  Since the device is still connected to
                // bs, any subsequent I/O is a use-after-free.

The value of bs->drv becomes unpredictable on free.  As long as it
remains null, I/O still gets dropped, however it could become non-null
at any point after the free resulting SEGVs or other QEMU state
corruption.

To resolve this issue as simply as possible, we can chose to not
actually delete the BlockDriverState pointer.  Since bdrv_close()
handles setting the drv pointer to NULL, we just need to remove the
BlockDriverState from the QLIST that is used to enumerate the block
devices.  This is currently handled within bdrv_delete, so move this
into its own function, bdrv_make_anon().

The result is that we can now invoke drive_del, this closes the file
descriptors and sets BlockDriverState->drv to NULL which prevents futher
IO to the device, and since we do not free BlockDriverState, we don't
have to worry about the copy retained in the block devices.

We also don't attempt to remove the qdev property since we are no longer
deleting the BlockDriverState on drives with associated drives.  This
also allows for removing Drives with no devices associated either.
Reported-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NRyan Harper <ryanh@us.ibm.com>
Acked-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      d22b2f41
  23. 20 2月, 2011 1 次提交
  25. 07 2月, 2011 1 次提交
  27. 31 1月, 2011 1 次提交
  29. 17 12月, 2010 2 次提交
  31. 04 11月, 2010 1 次提交
  33. 22 10月, 2010 1 次提交
    • E
      Copy snapshots out of QCOW2 disk · 51ef6727
      由 edison 提交于 
      In order to backup snapshots, created from QCOW2 iamge, we want to copy snapshots out of QCOW2 disk to a seperate storage.
The following patch adds a new option in "qemu-img": qemu-img convert -f qcow2 -O qcow2 -s snapshot_name src_img bck_img.
Right now, it only supports to copy the full snapshot, delta snapshot is on the way.

Changes from V1: all the comments from Kevin are addressed:
Add read-only checking
Fix coding style
Change the name from bdrv_snapshot_load to bdrv_snapshot_load_tmp
Signed-off-by: NDisheng Su <edison@cloud.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      51ef6727
  35. 08 9月, 2010 1 次提交
    • K
      block: Fix BDRV_O_CACHE_MASK · ceb25e5c
      由 Kevin Wolf 提交于 
      BDRV_O_CACHE_MASK should have been extended when cache=unsafe introduced a new
flag BDRV_O_NO_FLUSH. There are currently no users that would change their
behaviour because of this, but let's clean it up before things break.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      ceb25e5c
  37. 26 7月, 2010 1 次提交
  39. 06 7月, 2010 1 次提交
  41. 02 7月, 2010 3 次提交
    • M
      block: Fix virtual media change for if=none · 7d0d6950
      由 Markus Armbruster 提交于 
      BlockDriverState member removable controls whether virtual media
change (monitor commands change, eject) is allowed.  It is set when
the "type hint" is BDRV_TYPE_CDROM or BDRV_TYPE_FLOPPY.

The type hint is only set by drive_init().  It sets BDRV_TYPE_FLOPPY
for if=floppy.  It sets BDRV_TYPE_CDROM for media=cdrom and if=ide,
scsi, xen, or none.

if=ide and if=scsi work, because the type hint makes it a CD-ROM.
if=xen likewise, I think.

For the same reason, if=none works when it's used by ide-drive or
scsi-disk.  For other guest devices, there are problems:

* fdc: you can't change virtual media

    $ qemu [...] -drive if=none,id=foo,... -global isa-fdc.driveA=foo
    QEMU 0.12.50 monitor - type 'help' for more information
    (qemu) eject foo
    Device 'foo' is not removable

  unless you add media=cdrom, but that makes it readonly.

* virtio: if you add media=cdrom, you can change virtual media.  If
  you eject, the guest gets I/O errors.  If you change, the guest sees
  the drive's contents suddenly change.

* scsi-generic: if you add media=cdrom, you can change virtual media.
  I didn't test what that does to the guest or the physical device,
  but it can't be pretty.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      7d0d6950
    • M
      savevm: Survive hot-unplug of snapshot device · f9092b10
      由 Markus Armbruster 提交于 
      savevm.c keeps a pointer to the snapshot block device.  If you manage
to get that device deleted, the pointer dangles, and the next snapshot
operation will crash & burn.  Unplugging a guest device that uses it
does the trick:

    $ MALLOC_PERTURB_=234 qemu-system-x86_64 [...]
    QEMU 0.12.50 monitor - type 'help' for more information
    (qemu) info snapshots
    No available block device supports snapshots
    (qemu) drive_add auto if=none,file=tmp.qcow2
    OK
    (qemu) device_add usb-storage,id=foo,drive=none1
    (qemu) info snapshots
    Snapshot devices: none1
    Snapshot list (from none1):
    ID        TAG                 VM SIZE                DATE       VM CLOCK
    (qemu) device_del foo
    (qemu) info snapshots
    Snapshot devices:
    Segmentation fault (core dumped)

Move management of that pointer to block.c, and zap it when the device
it points becomes unusable.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      f9092b10
    • M
      block: Catch attempt to attach multiple devices to a blockdev · 18846dee
      由 Markus Armbruster 提交于 
      For instance, -device scsi-disk,drive=foo -device scsi-disk,drive=foo
happily creates two SCSI disks connected to the same block device.
It's all downhill from there.

Device usb-storage deliberately attaches twice to the same blockdev,
which fails with the fix in place.  Detach before the second attach
there.

Also catch attempt to delete while a guest device model is attached.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      18846dee
  43. 22 6月, 2010 1 次提交
    • K
      block: Add bdrv_(p)write_sync · f08145fe
      由 Kevin Wolf 提交于 
      Add new functions that write and flush the written data to disk immediately.
This is what needs to be used for image format metadata to maintain integrity
for cache=... modes that don't use O_DSYNC. (Actually, we only need barriers,
and therefore the functions are defined as such, but flushes is what is
implemented in this patch - we can try to change that later)
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      f08145fe
  45. 15 6月, 2010 4 次提交
    • M
      block: New bdrv_next() · 2f399b0a
      由 Markus Armbruster 提交于 
      This is a more flexible alternative to bdrv_iterate().
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      2f399b0a
    • M
      block: Decouple block device "commit all" from DriveInfo · 6ab4b5ab
      由 Markus Armbruster 提交于 
      do_commit() and mux_proc_byte() iterate over the list of drives
defined with drive_init().  This misses host block devices defined by
other means.  Such means don't exist now, but will be introduced later
in this series.

Change them to use new bdrv_commit_all(), which iterates over all host
block devices.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      6ab4b5ab
    • M
      block: Move error actions from DriveInfo to BlockDriverState · abd7f68d
      由 Markus Armbruster 提交于 
      That's where they belong semantically (block device host part), even
though the actions are actually executed by guest device code.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      abd7f68d
    • M
      savevm: Really verify if a drive supports snapshots · feeee5ac
      由 Miguel Di Ciurcio Filho 提交于 
      Both bdrv_can_snapshot() and bdrv_has_snapshot() does not work as advertized.

First issue: Their names implies different porpouses, but they do the same thing
and have exactly the same code. Maybe copied and pasted and forgotten?
bdrv_has_snapshot() is called in various places for actually checking if there
is snapshots or not.

Second issue: the way bdrv_can_snapshot() verifies if a block driver supports or
not snapshots does not catch all cases. E.g.: a raw image.

So when do_savevm() is called, first thing it does is to set a global
BlockDriverState to save the VM memory state calling get_bs_snapshots().

static BlockDriverState *get_bs_snapshots(void)
{
    BlockDriverState *bs;
    DriveInfo *dinfo;

    if (bs_snapshots)
        return bs_snapshots;
    QTAILQ_FOREACH(dinfo, &drives, next) {
        bs = dinfo->bdrv;
        if (bdrv_can_snapshot(bs))
            goto ok;
    }
    return NULL;
 ok:
    bs_snapshots = bs;
    return bs;
}

bdrv_can_snapshot() may return a BlockDriverState that does not support
snapshots and do_savevm() goes on.

Later on in do_savevm(), we find:

    QTAILQ_FOREACH(dinfo, &drives, next) {
        bs1 = dinfo->bdrv;
        if (bdrv_has_snapshot(bs1)) {
            /* Write VM state size only to the image that contains the state */
            sn->vm_state_size = (bs == bs1 ? vm_state_size : 0);
            ret = bdrv_snapshot_create(bs1, sn);
            if (ret < 0) {
                monitor_printf(mon, "Error while creating snapshot on '%s'\n",
                               bdrv_get_device_name(bs1));
            }
        }
    }

bdrv_has_snapshot(bs1) is not checking if the device does support or has
snapshots as explained above. Only in bdrv_snapshot_create() the device is
actually checked for snapshot support.

So, in cases where the first device supports snapshots, and the second does not,
the snapshot on the first will happen anyways. I believe this is not a good
behavior. It should be an all or nothing process.

This patch addresses these issues by making bdrv_can_snapshot() actually do
what it must do and enforces better tests to avoid errors in the middle of
do_savevm(). bdrv_has_snapshot() is removed and replaced by bdrv_can_snapshot()
where appropriate.

bdrv_can_snapshot() was moved from savevm.c to block.c. It makes more sense to me.

The loadvm_state() function was updated too to enforce that when loading a VM at
least all writable devices must support snapshots too.
Signed-off-by: NMiguel Di Ciurcio Filho <miguel.filho@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      feeee5ac
  47. 04 6月, 2010 1 次提交
  49. 28 5月, 2010 1 次提交