diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2018-02-07 16:38:05 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2018-03-09 15:17:48 +0100 |
| commit | 89b259eeaa0f4ad3fa89cbe500da9335536e20ee (patch) | |
| tree | 01656995c7920de5b036a78703931d9928585185 /block/file-posix.c | |
| parent | 4906da7e4de3720995b644f9903879cfd5a51a40 (diff) | |
| download | qemu-89b259eeaa0f4ad3fa89cbe500da9335536e20ee.tar.gz | |
file-posix: Fix no-op bdrv_truncate() with falloc preallocation
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>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'block/file-posix.c')
| -rw-r--r-- | block/file-posix.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/block/file-posix.c b/block/file-posix.c index fbc21a9921..d7fb772c14 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1686,11 +1686,15 @@ 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 |