static bool
preallocate_file_sparse (tr_sys_file_t fd, uint64_t length, tr_error ** error)
{
tr_error * my_error = NULL;
if (length == 0)
return true;
if (tr_sys_file_preallocate (fd, length, TR_SYS_FILE_PREALLOC_SPARSE, &my_error))
return true;
dbgmsg ("Preallocating (sparse, normal) failed (%d): %s", my_error->code, my_error->message);
if (!TR_ERROR_IS_ENOSPC (my_error->code))
{
const char zero = '\0';
tr_error_clear (&my_error);
/* fallback: the old-style seek-and-write */
if (tr_sys_file_write_at (fd, &zero, 1, length - 1, NULL, &my_error) &&
tr_sys_file_truncate (fd, length, &my_error))
return true;
dbgmsg ("Preallocating (sparse, fallback) failed (%d): %s", my_error->code, my_error->message);
}
tr_error_propagate (error, &my_error);
return false;
}
bool tr_sys_file_preallocate(tr_sys_file_t handle, uint64_t size, int flags, tr_error** error)
{
TR_ASSERT(handle != TR_BAD_SYS_FILE);
if ((flags & TR_SYS_FILE_PREALLOC_SPARSE) != 0)
{
DWORD tmp;
if (!DeviceIoControl(handle, FSCTL_SET_SPARSE, NULL, 0, NULL, 0, &tmp, NULL))
{
set_system_error(error, GetLastError());
return false;
}
}
return tr_sys_file_truncate(handle, size, error);
}
/**
* returns 0 on success, or an errno value on failure.
* errno values include ENOENT if the parent folder doesn't exist,
* plus the errno values set by tr_sys_dir_create () and tr_sys_file_open ().
*/
static int
cached_file_open (struct tr_cached_file * o,
const char * filename,
bool writable,
tr_preallocation_mode allocation,
uint64_t file_size)
{
int flags;
tr_sys_path_info info;
bool already_existed;
bool resize_needed;
tr_sys_file_t fd = TR_BAD_SYS_FILE;
tr_error * error = NULL;
/* create subfolders, if any */
if (writable)
{
char * dir = tr_sys_path_dirname (filename, NULL);
if (!tr_sys_dir_create (dir, TR_SYS_DIR_CREATE_PARENTS, 0777, &error))
{
tr_logAddError (_("Couldn't create \"%1$s\": %2$s"), dir, error->message);
tr_free (dir);
goto fail;
}
tr_free (dir);
}
already_existed = tr_sys_path_get_info (filename, 0, &info, NULL) && info.type == TR_SYS_PATH_IS_FILE;
/* we can't resize the file w/o write permissions */
resize_needed = already_existed && (file_size < info.size);
writable |= resize_needed;
/* open the file */
flags = writable ? (TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE) : 0;
flags |= TR_SYS_FILE_READ | TR_SYS_FILE_SEQUENTIAL;
fd = tr_sys_file_open (filename, flags, 0666, &error);
if (fd == TR_BAD_SYS_FILE)
{
tr_logAddError (_("Couldn't open \"%1$s\": %2$s"), filename, error->message);
goto fail;
}
if (writable && !already_existed && allocation != TR_PREALLOCATE_NONE)
{
bool success = false;
const char * type = NULL;
if (allocation == TR_PREALLOCATE_FULL)
{
success = preallocate_file_full (fd, file_size, &error);
type = _("full");
}
else if (allocation == TR_PREALLOCATE_SPARSE)
{
success = preallocate_file_sparse (fd, file_size, &error);
type = _("sparse");
}
assert (type != NULL);
if (!success)
{
tr_logAddError (_("Couldn't preallocate file \"%1$s\" (%2$s, size: %3$"PRIu64"): %4$s"),
filename, type, file_size, error->message);
goto fail;
}
tr_logAddDebug (_("Preallocated file \"%1$s\" (%2$s, size: %3$"PRIu64")"), filename, type, file_size);
}
/* If the file already exists and it's too large, truncate it.
* This is a fringe case that happens if a torrent's been updated
* and one of the updated torrent's files is smaller.
* http://trac.transmissionbt.com/ticket/2228
* https://bugs.launchpad.net/ubuntu/+source/transmission/+bug/318249
*/
if (resize_needed && !tr_sys_file_truncate (fd, file_size, &error))
{
tr_logAddError (_("Couldn't truncate \"%1$s\": %2$s"), filename, error->message);
goto fail;
}
o->fd = fd;
return 0;
fail:
{
const int err = error->code;
tr_error_free (error);
if (fd != TR_BAD_SYS_FILE)
tr_sys_file_close (fd, NULL);
return err;
}
}
