Commit Graph

12 Commits

Author SHA1 Message Date
Kevin Wolf
205ef7961f block: Allow bdrv_flush to return errors
This changes bdrv_flush to return 0 on success and -errno in case of failure.
It's a requirement for implementing proper error handle in users of bdrv_flush.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2010-11-04 12:52:16 +01:00
Kevin Wolf
b0ad5a455d cow: Use bdrv_(p)write_sync for metadata writes
Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash.
While at it, correct the wrong usage of errno.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-22 14:38:02 +02:00
Christoph Hellwig
2063392ae5 cow: use qemu block API
Use bdrv_pwrite to access the backing device instead of pread, and
convert the driver to implementing the bdrv_open method which gives
it an already opened BlockDriverState for the underlying device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15 09:41:59 +02:00
Christoph Hellwig
893a9cb47c cow: stop using mmap
We don't have an equivalent to mmap in the qemu block API, so read and
write the bitmap directly.  At least in the dumb implementation added
in this patch this is a lot less efficient, but it means cow can also
work on windows, and over nbd or curl.  And it fixes qemu-iotests testcase
012 which did not work properly due to issues with read-only mmap access.

In addition we can also get rid of the now unused get_mmap_addr function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15 09:41:59 +02:00
Christoph Hellwig
122bb9e32d cow: use pread/pwrite
Use pread/pwrite instead of lseek + read/write in preparation of using the
qemu block API.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-06-15 09:41:59 +02:00
Kevin Wolf
66f82ceed6 block: Open the underlying image file in generic code
Format drivers shouldn't need to bother with things like file names, but rather
just get an open BlockDriverState for the underlying protocol. This patch
introduces this behaviour for bdrv_open implementation. For protocols which
need to access the filename to open their file/device/connection/... a new
callback bdrv_file_open is introduced which doesn't get an underlying file
opened.

For now, also some of the more obscure formats use bdrv_file_open because they
open() the file themselves instead of using the block.c functions. They need to
be fixed in later patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-05-03 10:07:30 +02:00
Juan Quintela
48b66db9ea cow: return errno instead of -1
Remove not needed ret = 0 assignment.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-09 11:22:59 -06:00
Kirill A. Shutemov
31f38120a9 block/cow.c: fix warnings with _FORTIFY_SOURCE
CC    block/cow.o
cc1: warnings being treated as errors
block/cow.c: In function 'cow_create':
block/cow.c:251: error: ignoring return value of 'write', declared with attribute warn_unused_result
block/cow.c:253: error: ignoring return value of 'ftruncate', declared with attribute warn_unused_result
make: *** [block/cow.o] Error 1

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-01-26 14:59:20 -06:00
Christoph Hellwig
6f1953c4c1 block: use fdatasync instead of fsync if possible
If we are flushing the caches for our image files we only care about the
data (including the metadata required for accessing it) but not things
like timestamp updates.  So try to use fdatasync instead of fsync to
implement the flush operations.

Unfortunately many operating systems still do not support fdatasync,
so we add a qemu_fdatasync wrapper that uses fdatasync if available
as per the _POSIX_SYNCHRONIZED_IO feature macro or fsync otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-09-11 10:19:46 -05:00
Kevin Wolf
db08adf526 qemu-img: Print available options with -o ?
This patch adds a small help text to each of the options in the block drivers
which can be displayed by using qemu-img create -f fmt -o ?

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2009-06-06 18:38:57 +03:00
Kevin Wolf
0e7e1989f7 Convert all block drivers to new bdrv_create
Now we can make use of the newly introduced option structures. Instead of
having bdrv_create carry more and more parameters (which are format specific in
most cases), just pass a option structure as defined by the driver itself.

bdrv_create2() contains an emulation of the old interface to simplify the
transition.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-22 10:50:31 -05:00
Anthony Liguori
019d6b8ff0 Move block drivers into their own directory
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-05-14 16:13:46 -05:00