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  1. 15 11月, 2013 1 次提交
  3. 14 11月, 2013 1 次提交
    • F
      block: Print its file name if backing file opening failed · b04b6b6e
      由 Fam Zheng 提交于 
      If backing file doesn't exist, the error message is confusing and
misleading:

    $ qemu /tmp/a.qcow2
    qemu: could not open disk image /tmp/a.qcow2: Could not open file: No
    such file or directory

But...

    $ ls /tmp/a.qcow2
    /tmp/a.qcow2

    $ qemu-img info /tmp/a.qcow2
    image: /tmp/a.qcow2
    file format: qcow2
    virtual size: 8.0G (8589934592 bytes)
    disk size: 196K
    cluster_size: 65536
    backing file: /tmp/b.qcow2

Because...

    $ ls /tmp/b.qcow2
    ls: cannot access /tmp/b.qcow2: No such file or directory

This is not intuitive. It's better to have the missing file's name in
the error message. With this patch:

    $ qemu-io -c 'read 0 512' /tmp/a.qcow2
    qemu-io: can't open device /tmp/a.qcow2: Could not open backing
    file: Could not open '/stor/vm/arch.raw': No such file or directory
    no file open, try 'help open'

Which is a little bit better.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      b04b6b6e
  5. 08 11月, 2013 1 次提交
  7. 07 11月, 2013 1 次提交
  9. 29 10月, 2013 3 次提交
    • K
      block: Avoid unecessary drv->bdrv_getlength() calls · b94a2610
      由 Kevin Wolf 提交于 
      The block layer generally keeps the size of an image cached in
bs->total_sectors so that it doesn't have to perform expensive
operations to get the size whenever it needs it.

This doesn't work however when using a backend that can change its size
without qemu being aware of it, i.e. passthrough of removable media like
CD-ROMs or floppy disks. For this reason, the caching is disabled when a
removable device is used.

It is obvious that checking whether the _guest_ device has removable
media isn't the right thing to do when we want to know whether the size
of the host backend can change. To make things worse, non-top-level
BlockDriverStates never have any device attached, which makes qemu
assume they are removable, so drv->bdrv_getlength() is always called on
the protocol layer. In the case of raw-posix, this causes unnecessary
lseek() system calls, which turned out to be rather expensive.

This patch completely changes the logic and disables bs->total_sectors
caching only for certain block driver types, for which a size change is
expected: host_cdrom and host_floppy on POSIX, host_device on win32; also
the raw format in case it sits on top of one of these protocols, but in
the common case the nested bdrv_getlength() call on the protocol driver
will use the cache again and avoid an expensive drv->bdrv_getlength()
call.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
      b94a2610
    • T
      block: Disable BDRV_O_COPY_ON_READ for the backing file · 87a5debd
      由 Thibaut LAURENT 提交于 
      Since commit 0ebd24e0,
bdrv_open_common will throw an error when trying to open a file
read-only with the BDRV_O_COPY_ON_READ flag set.
Although BDRV_O_RDWR is unset for the backing files,
BDRV_O_COPY_ON_READ is still passed on if copy-on-read was requested
for the drive. Let's unset this flag too before opening the backing
file, or bdrv_open_common will fail.
Signed-off-by: NThibaut LAURENT <thibaut.laurent@gmail.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      87a5debd
    • M
      block: Don't copy backing file name on error · 61ed2684
      由 Max Reitz 提交于 
      bdrv_open_backing_file() tries to copy the backing file name using
pstrcpy directly after calling bdrv_open() to open the backing file
without checking whether that was actually successful. If it was not,
ps->backing_hd->file will probably be NULL and qemu will crash.

Fix this by moving pstrcpy after checking whether bdrv_open() succeeded.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: Amos_沧海桑田's avatarAmos Kong <kongjianjun@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      61ed2684
  11. 11 10月, 2013 5 次提交
  13. 07 10月, 2013 1 次提交
  15. 02 10月, 2013 1 次提交
  17. 26 9月, 2013 1 次提交
  19. 25 9月, 2013 5 次提交
  21. 21 9月, 2013 1 次提交
  23. 12 9月, 2013 5 次提交
  25. 06 9月, 2013 14 次提交