| Message ID | 20180208192328.16550-25-kwolf@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2018-02-08 20:23, Kevin Wolf wrote: > If bdrv_truncate() is called, but the requested size is the same as > before, don't call posix_fallocate(), which returns -EINVAL for length > zero and would therefore make bdrv_truncate() fail. > > The problem can be triggered by creating a zero-sized raw image with > 'falloc' preallocation mode. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > block/file-posix.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) Reviewed-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/file-posix.c b/block/file-posix.c index 9ae5b7dcdf..15819a00b9 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1683,11 +1683,15 @@ static int raw_regular_truncate(int fd, int64_t offset, PreallocMode prealloc, * file systems that do not support fallocate(), trying to check if a * block is allocated before allocating it, so don't do that here. */ - result = -posix_fallocate(fd, current_length, offset - current_length); - if (result != 0) { - /* posix_fallocate() doesn't set errno. */ - error_setg_errno(errp, -result, - "Could not preallocate new data"); + if (offset != current_length) { + result = -posix_fallocate(fd, current_length, offset - current_length); + if (result != 0) { + /* posix_fallocate() doesn't set errno. */ + error_setg_errno(errp, -result, + "Could not preallocate new data"); + } + } else { + result = 0; } goto out; #endif
If bdrv_truncate() is called, but the requested size is the same as before, don't call posix_fallocate(), which returns -EINVAL for length zero and would therefore make bdrv_truncate() fail. The problem can be triggered by creating a zero-sized raw image with 'falloc' preallocation mode. Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- block/file-posix.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)