gluster: Query current size in do_truncate()

Instead of expecting the current size to be 0, query it and allocate
only the area [current_size, offset) if preallocation is requested.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2018-02-13 14:03:52 +01:00 committed by Kevin Wolf
parent 36e87909f8
commit f3a33f795c

View file

@ -968,10 +968,27 @@ static coroutine_fn int qemu_gluster_co_pwrite_zeroes(BlockDriverState *bs,
static int qemu_gluster_do_truncate(struct glfs_fd *fd, int64_t offset,
PreallocMode prealloc, Error **errp)
{
int64_t current_length;
current_length = glfs_lseek(fd, 0, SEEK_END);
if (current_length < 0) {
error_setg_errno(errp, errno, "Failed to determine current size");
return -errno;
}
if (current_length > offset && prealloc != PREALLOC_MODE_OFF) {
error_setg(errp, "Cannot use preallocation for shrinking files");
return -ENOTSUP;
}
if (current_length == offset) {
return 0;
}
switch (prealloc) {
#ifdef CONFIG_GLUSTERFS_FALLOCATE
case PREALLOC_MODE_FALLOC:
if (glfs_fallocate(fd, 0, 0, offset)) {
if (glfs_fallocate(fd, 0, current_length, offset - current_length)) {
error_setg_errno(errp, errno, "Could not preallocate data");
return -errno;
}
@ -983,7 +1000,7 @@ static int qemu_gluster_do_truncate(struct glfs_fd *fd, int64_t offset,
error_setg_errno(errp, errno, "Could not resize file");
return -errno;
}
if (glfs_zerofill(fd, 0, offset)) {
if (glfs_zerofill(fd, current_length, offset - current_length)) {
error_setg_errno(errp, errno, "Could not zerofill the new area");
return -errno;
}