Linux 4.1: Don't define or use ->write directly

We no longer have to define a ->write operation, and we can't
expect the underlying disk cache filesystem to have one.  Use
the new __vfs_read/write helpers that will select the operation
to use based on what's available for that particular filesystem.

Change-Id: Iab923235308ff57348ffc2dc6d718dd64040656b
Reviewed-on: http://gerrit.openafs.org/11849
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams <3chas3@gmail.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>

diff --git a/acinclude.m4 b/acinclude.m4
index f82248c..959e3c5 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -966,6 +966,9 @@ case $AFS_SYSNAME in *_linux* | *_umlinux*)
 
                 dnl Function existence checks
 
+                AC_CHECK_LINUX_FUNC([__vfs_read],
+                                    [#include <linux/fs.h>],
+                                    [__vfs_read(NULL, NULL, 0, NULL);])
                  AC_CHECK_LINUX_FUNC([bdi_init],
                                     [#include <linux/backing-dev.h>],
                                     [bdi_init(NULL);])

diff --git a/src/afs/LINUX/osi_compat.h b/src/afs/LINUX/osi_compat.h
index e8816d5..e9f6ca1 100644 (file)
--- a/src/afs/LINUX/osi_compat.h
+++ b/src/afs/LINUX/osi_compat.h
@@ -631,4 +631,24 @@ afs_d_invalidate(struct dentry *dp)
 #endif
 }
 
+static inline int
+afs_file_read(struct file *filp, char __user *buf, size_t len, loff_t *pos)
+{
+#if defined(HAVE_LINUX___VFS_READ)
+    return __vfs_read(filp, buf, len, pos);
+#else
+    return filp->f_op->read(filp, buf, len, pos);
+#endif
+}
+
+static inline int
+afs_file_write(struct file *filp, char __user *buf, size_t len, loff_t *pos)
+{
+#if defined(HAVE_LINUX___VFS_READ)
+    return __vfs_write(filp, buf, len, pos);
+#else
+    return filp->f_op->write(filp, buf, len, pos);
+#endif
+}
+
 #endif /* AFS_LINUX_OSI_COMPAT_H */

diff --git a/src/afs/LINUX/osi_file.c b/src/afs/LINUX/osi_file.c
index 8cdff4b..c050715 100644 (file)
--- a/src/afs/LINUX/osi_file.c
+++ b/src/afs/LINUX/osi_file.c
@@ -375,9 +375,9 @@ osi_rdwr(struct osi_file *osifile, struct uio *uiop, int rw)
 
        pos = uiop->uio_offset;
        if (rw == UIO_READ)
-           code = filp->f_op->read(filp, iov->iov_base, count, &pos);
+           code = afs_file_read(filp, iov->iov_base, count, &pos);
        else
-           code = filp->f_op->write(filp, iov->iov_base, count, &pos);
+           code = afs_file_write(filp, iov->iov_base, count, &pos);
 
        if (code < 0) {
            code = -code;

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 5869eb9..5b9d5aa 100644 (file)
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -819,8 +819,10 @@ struct file_operations afs_file_fops = {
 #ifdef STRUCT_FILE_OPERATIONS_HAS_READ_ITER
   .read_iter = afs_linux_read_iter,
   .write_iter =        afs_linux_write_iter,
+# if !defined(HAVE_LINUX___VFS_READ)
   .read =      new_sync_read,
   .write =     new_sync_write,
+# endif
 #elif defined(HAVE_LINUX_GENERIC_FILE_AIO_READ)
   .aio_read =  afs_linux_aio_read,
   .aio_write = afs_linux_aio_write,