new helper: generic_file_read_iter()

iov_iter-using variant of generic_file_aio_read().  Some callers
converted.  Note that it's still not quite there for use as ->read_iter() -
we depend on having zero iter->iov_offset in O_DIRECT case.  Fortunately,
that's true for all converted callers (and for generic_file_aio_read() itself).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 2 insertions, 15 deletions

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index d8f383d59449..910a3022eb27 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -833,24 +833,11 @@ again:
                 /* hmm, this isn't really async... */
                 ret = ceph_sync_read(iocb, &i, &checkeof);
         } else {
-                /*
-                 * We can't modify the content of iov,
-                 * so we only read from beginning.
-                 *
-                 * When we switch generic_file_aio_read() to iov_iter, the
-                 * if () below will be removed -- AV
-                 */
-                if (read) {
-                        iocb->ki_pos = pos;
-                        len = iocb->ki_nbytes;
-                        read = 0;
-                        iov_iter_init(&i, iov, nr_segs, len, 0);
-                }
                 dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
                      inode, ceph_vinop(inode), pos, (unsigned)len,
                      ceph_cap_string(got));
 
-                ret = generic_file_aio_read(iocb, iov, nr_segs, pos);
+                ret = generic_file_read_iter(iocb, &i);
         }
         dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
              inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 3d01b152894e..a352bc6d613f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -184,7 +184,7 @@ nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
 
         result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
         if (!result) {
-                result = generic_file_aio_read(iocb, iov, nr_segs, pos);
+                result = generic_file_read_iter(iocb, &to);
                 if (result > 0)
                         nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
         }