diff options
| -rw-r--r-- | block/file-posix.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/block/file-posix.c b/block/file-posix.c index d24e34be36..4de1abd023 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -1594,9 +1594,14 @@ static int raw_create(const char *filename, QemuOpts *opts, Error **errp) switch (prealloc) { #ifdef CONFIG_POSIX_FALLOCATE case PREALLOC_MODE_FALLOC: - /* posix_fallocate() doesn't set errno. */ + /* + * Truncating before posix_fallocate() makes it about twice slower on + * 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, 0, total_size); if (result != 0) { + /* posix_fallocate() doesn't set errno. */ error_setg_errno(errp, -result, "Could not preallocate data for the new file"); } |