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  1. 13 3月, 2019 13 次提交
    • A
      block: Allow freezing BdrvChild links · 2cad1ebe
      由 Alberto Garcia 提交于 
      Our permission system is useful to define what operations are allowed
on a certain block node and includes things like BLK_PERM_WRITE or
BLK_PERM_RESIZE among others.

One of the permissions is BLK_PERM_GRAPH_MOD which allows "changing
the node that this BdrvChild points to". The exact meaning of this has
never been very clear, but it can be understood as "change any of the
links connected to the node". This can be used to prevent changing a
backing link, but it's too coarse.

This patch adds a new 'frozen' attribute to BdrvChild, which forbids
detaching the link from the node it points to, and new API to freeze
and unfreeze a backing chain.

After this change a few functions can fail, so they need additional
checks.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      2cad1ebe
    • K
      nvme: fix write zeroes offset and count · 9d6459d2
      由 Keith Busch 提交于 
      The implementation used blocks units rather than the expected bytes.

Fixes: c03e7ef1 ("nvme: Implement Write Zeroes")
Reported-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      9d6459d2
    • K
      file-posix: Make auto-read-only dynamic · 23dece19
      由 Kevin Wolf 提交于 
      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: NKevin Wolf <kwolf@redhat.com>
      23dece19
    • K
      file-posix: Prepare permission code for fd switching · 6ceabe6f
      由 Kevin Wolf 提交于 
      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: NKevin Wolf <kwolf@redhat.com>
      6ceabe6f
    • K
      file-posix: Lock new fd in raw_reopen_prepare() · a6aeca0c
      由 Kevin Wolf 提交于 
      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: NKevin Wolf <kwolf@redhat.com>
      a6aeca0c
    • K
      file-posix: Store BDRVRawState.reopen_state during reopen · e0c9cf3a
      由 Kevin Wolf 提交于 
      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: NKevin Wolf <kwolf@redhat.com>
      e0c9cf3a
    • K
      file-posix: Factor out raw_reconfigure_getfd() · 5cec2870
      由 Kevin Wolf 提交于 
      Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      5cec2870
    • K
      file-posix: Fix bdrv_open_flags() for snapshot=on · 30855137
      由 Kevin Wolf 提交于 
      Using a different read-only setting for bs->open_flags than for the
flags to the driver's open function is just inconsistent and a bad idea.
After this patch, the temporary snapshot keeps being opened read-only if
read-only=on,snapshot=on is passed.

If we wanted to change this behaviour to make only the orginal image
file read-only, but the temporary overlay read-write (as the comment in
the removed code suggests), that change would have to be made in
bdrv_temp_snapshot_options() (where the comment suggests otherwise).

Addressing this inconsistency before introducing dynamic auto-read-only
is important because otherwise we would immediately try to reopen the
temporary overlay even though the file is already unlinked.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      30855137
    • K
      block: Make permission changes in reopen less wrong · 69b736e7
      由 Kevin Wolf 提交于 
      The way that reopen interacts with permission changes has one big
problem: Both operations are recursive, and the permissions are changes
for each node in the reopen queue.

For a simple graph that consists just of parent and child,
.bdrv_check_perm will be called twice for the child, once recursively
when adjusting the permissions of parent, and once again when the child
itself is reopened.

Even worse, the first .bdrv_check_perm call happens before
.bdrv_reopen_prepare was called for the child and the second one is
called afterwards.

Making sure that .bdrv_check_perm (and the other permission callbacks)
are called only once is hard. We can cope with multiple calls right now,
but as soon as file-posix gets a dynamic auto-read-only that may need to
open a new file descriptor, we get the additional requirement that all
of them are after the .bdrv_reopen_prepare call.

So reorder things in bdrv_reopen_multiple() to first call
.bdrv_reopen_prepare for all involved nodes and only then adjust
permissions.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      69b736e7
    • K
      block: Avoid useless local_err · a4615ab3
      由 Kevin Wolf 提交于 
      Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      a4615ab3
    • K
      qemu-iotests: commit to backing file with auto-read-only · 12efe428
      由 Kevin Wolf 提交于 
      Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      12efe428
    • K
      tests/virtio-blk-test: Disable auto-read-only · 70304118
      由 Kevin Wolf 提交于 
      tests/virtio-blk-test uses a temporary image file that it deletes while
QEMU is still running, so it can't be reopened when writers are
attached or detached. Disable auto-read-only to keep it always writable.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
      70304118
    • V
      qapi: drop x- from x-block-latency-histogram-set · cb8aac37
      由 Vladimir Sementsov-Ogievskiy 提交于 
      Drop x- and x_ prefixes for latency histograms and update version to
4.0
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      cb8aac37
  3. 12 3月, 2019 27 次提交