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  • Anton Anton anjo
1 author
  1. Jan 26, 2012
  3. Dec 05, 2011
  5. Nov 21, 2011
    • Anthony Liguori's avatar
      block: allow migration to work with image files (v3) · 0f15423c
      Anthony Liguori authored 
      
Image files have two types of data: immutable data that describes things like
image size, backing files, etc. and mutable data that includes offset and
reference count tables.

Today, image formats aggressively cache mutable data to improve performance.  In
some cases, this happens before a guest even starts.  When dealing with live
migration, since a file is open on two machines, the caching of meta data can
lead to data corruption.

This patch addresses this by introducing a mechanism to invalidate any cached
mutable data a block driver may have which is then used by the live migration
code.

NB, this still requires coherent shared storage.  Addressing migration without
coherent shared storage (i.e. NFS) requires additional work.

Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
      0f15423c
  7. Nov 11, 2011
    • Kevin Wolf's avatar
      block: Introduce bdrv_co_flush_to_os · eb489bb1
      Kevin Wolf authored 
      
qcow2 has a writeback metadata cache, so flushing a qcow2 image actually
consists of writing back that cache to the protocol and only then flushes the
protocol in order to get everything stable on disk.

This introduces a separate bdrv_co_flush_to_os to reflect the split.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      eb489bb1
    • Kevin Wolf's avatar
      block: Rename bdrv_co_flush to bdrv_co_flush_to_disk · c68b89ac
      Kevin Wolf authored 
      
There are two different types of flush that you can do: Flushing one level up
to the OS (i.e. writing data to the host page cache) or flushing it all the way
down to the disk. The existing functions flush to the disk, reflect this in the
function name.

Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      c68b89ac
  9. Oct 27, 2011
  11. Oct 21, 2011
  13. Oct 11, 2011
    • Luiz Capitulino's avatar
      block: Keep track of devices' I/O status · 28a7282a
      Luiz Capitulino authored 
      
This commit adds support to the BlockDriverState type to keep track
of devices' I/O status.

There are three possible status: BDRV_IOS_OK (no error), BDRV_IOS_ENOSPC
(no space error) and BDRV_IOS_FAILED (any other error). The distinction
between no space and other errors is important because a management
application may want to watch for no space in order to extend the
space assigned to the VM and put it to run again.

Qemu devices supporting the I/O status feature have to enable it
explicitly by calling bdrv_iostatus_enable() _and_ have to be
configured to stop the VM on errors (ie. werror=stop|enospc or
rerror=stop).

In case of multiple errors being triggered in sequence only the first
one is stored. The I/O status is always reset to BDRV_IOS_OK when the
'cont' command is issued.

Next commits will add support to some devices and extend the
query-block/info block commands to return the I/O status information.

Signed-off-by: default avatarLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      28a7282a
  15. Sep 12, 2011
  17. Sep 06, 2011
  19. Aug 26, 2011
  21. Aug 25, 2011
    • Christoph Hellwig's avatar
      block: explicit I/O accounting · a597e79c
      Christoph Hellwig authored 
      
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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
      a597e79c
  23. Aug 23, 2011
  25. Aug 02, 2011
    • Kevin Wolf's avatar
      block: Add bdrv_co_readv/writev · da1fa91d
      Kevin Wolf authored 
      
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: default avatarKevin Wolf <kwolf@redhat.com>
      da1fa91d
  27. Aug 01, 2011
  29. Jul 19, 2011
  31. Jun 15, 2011
  33. May 19, 2011