On 2018-02-14 21:49, Max Reitz wrote: > For (x-)blockdev-create, all protocol drivers that support image > creation also need to offer a .bdrv_truncate() implementation that > matches in features. A previous series of mine brought gluster's and > sheepdog's implementation up to par regarding preallocated truncation; > but I forgot about drivers that have a .bdrv_create() but no > .bdrv_truncate() at all. > > There is only one of these, and that is ssh. Since libssh2 does not > seem to know any way of truncating files, we can only support growing > files -- but that is what we need for (x-)blockdev-create. > > Note that there are also drivers which do not support growing files, > namely iscsi and file-posix for host devices (maybe more? I hope not). > But these also pretty much ignore the specified size on .bdrv_create() > and just use the size of the existing device. They just check that the > specified size does not exceed the actual size, so that pretty much > matches what their .bdrv_truncate() supports, and we should be fine > there. > > > Max Reitz (3): > block/ssh: Pull ssh_grow_file() from ssh_create() > block/ssh: Make ssh_grow_file() blocking > block/ssh: Add basic .bdrv_truncate() > > block/ssh.c | 61 > +++++++++++++++++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 53 insertions(+), 8 deletions(-)
Applied to my block branch. Max
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