splice() may return -ERESTARTSYS if there are pending signals, and
it's not even clear how this should be dealt with. This potential
problem has been present for a long time, but as of Linux 4.4
(commit
c725bfce7968009756ed2836a8cd7ba4dc163011) seems much more
likely to happen.
Until resources are available to fix the code to handle such errors,
avoid the riskier uses of splice().
If there is a default implementation of file_splice_{write,read},
use that; on somewhat older kernels where it is not available,
use the generic version instead.
[kaduk@mit.edu: add test for default_file_splice_write]
Change-Id: Ib4477cdfb2cd0f49f516da75edc3cb9d1a8817dc
Reviewed-on: https://gerrit.openafs.org/12217
Reviewed-by: Chas Williams <3chas3@gmail.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
AC_CHECK_LINUX_FUNC([splice_direct_to_actor],
[#include <linux/splice.h>],
[splice_direct_to_actor(NULL,NULL,NULL);])
+ AC_CHECK_LINUX_FUNC([default_file_splice_read],
+ [#include <linux/fs.h>],
+ [default_file_splice_read(NULL,NULL,NULL, 0, 0);])
AC_CHECK_LINUX_FUNC([svc_addr_in],
[#include <linux/sunrpc/svc.h>],
[svc_addr_in(NULL);])
#include "afs/param.h"
#include <linux/fs.h>
-#if defined(HAVE_LINUX_SPLICE_DIRECT_TO_ACTOR)
+#if 0 && defined(HAVE_LINUX_SPLICE_DIRECT_TO_ACTOR)
# include <linux/splice.h>
#else
# include <linux/pipe_fs_i.h>
#include "afs/sysincludes.h"
#include "afsincludes.h"
-#if defined(HAVE_LINUX_SPLICE_DIRECT_TO_ACTOR)
+#if 0 && defined(HAVE_LINUX_SPLICE_DIRECT_TO_ACTOR)
static int
afs_linux_splice_actor(struct pipe_inode_info *pipe,
struct pipe_buffer *buf,
return size;
}
+#if 0
afs_int32
afs_linux_storeproc(struct storeOps *ops, void *rock, struct dcache *tdc,
int *shouldwake, afs_size_t *bytesXferred)
return code;
}
+#endif
#endif
#if defined(STRUCT_FILE_OPERATIONS_HAS_SENDFILE)
.sendfile = generic_file_sendfile,
#endif
-#if defined(STRUCT_FILE_OPERATIONS_HAS_SPLICE)
+#if defined(STRUCT_FILE_OPERATIONS_HAS_SPLICE) && !defined(HAVE_LINUX_DEFAULT_FILE_SPLICE_READ)
# if defined(HAVE_LINUX_ITER_FILE_SPLICE_WRITE)
.splice_write = iter_file_splice_write,
# else
.padd = rxfs_storePadd,
.close = rxfs_storeClose,
.destroy = rxfs_storeDestroy,
-#ifdef AFS_LINUX26_ENV
+#if 0 && defined(AFS_LINUX26_ENV)
.storeproc = afs_linux_storeproc
#else
.storeproc = afs_GenericStoreProc