orangefs: make do_readv_writev() take iov_iter

no need to build a copy of what the caller already has;
what's more, we want the one given to caller properly
advanced *and* we shouldn't depend upon it being an
iovec-backed one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index ff7fe37..8dae04d 100644 (file)
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -264,13 +264,12 @@ out:
  * Note: File extended attributes override any mount options.
  */
 static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
-               loff_t *offset, const struct iovec *iov, unsigned long nr_segs)
+               loff_t *offset, struct iov_iter *iter)
 {
        struct inode *inode = file->f_mapping->host;
        struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
        struct pvfs2_khandle *handle = &pvfs2_inode->refn.khandle;
-       struct iov_iter iter;
-       size_t count = iov_length(iov, nr_segs);
+       size_t count = iov_iter_count(iter);
        ssize_t total_count = 0;
        ssize_t ret = -EINVAL;
 
@@ -295,18 +294,13 @@ static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
                goto out;
        }
 
-       iov_iter_init(&iter, type == PVFS_IO_READ ? READ : WRITE,
-                             iov, nr_segs, count);
-
-       while (total_count < count) {
-               size_t each_count;
+       while (iov_iter_count(iter)) {
+               size_t each_count = iov_iter_count(iter);
                size_t amt_complete;
 
                /* how much to transfer in this loop iteration */
-               each_count =
-                  (((count - total_count) > pvfs_bufmap_size_query()) ?
-                       pvfs_bufmap_size_query() :
-                       (count - total_count));
+               if (each_count > pvfs_bufmap_size_query())
+                       each_count = pvfs_bufmap_size_query();
 
                gossip_debug(GOSSIP_FILE_DEBUG,
                             "%s(%pU): size of each_count(%d)\n",
@@ -319,7 +313,7 @@ static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
                             handle,
                             (int)*offset);
 
-               ret = wait_for_direct_io(type, inode, offset, &iter,
+               ret = wait_for_direct_io(type, inode, offset, iter,
                                each_count, 0);
                gossip_debug(GOSSIP_FILE_DEBUG,
                             "%s(%pU): return from wait_for_io:%d\n",
@@ -426,7 +420,6 @@ static ssize_t pvfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
        struct file *file = iocb->ki_filp;
        loff_t pos = *(&iocb->ki_pos);
        ssize_t rc = 0;
-       unsigned long nr_segs = iter->nr_segs;
 
        BUG_ON(iocb->private);
 
@@ -434,11 +427,7 @@ static ssize_t pvfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 
        g_pvfs2_stats.reads++;
 
-       rc = do_readv_writev(PVFS_IO_READ,
-                            file,
-                            &pos,
-                            iter->iov,
-                            nr_segs);
+       rc = do_readv_writev(PVFS_IO_READ, file, &pos, iter);
        iocb->ki_pos = pos;
 
        return rc;
@@ -448,7 +437,6 @@ static ssize_t pvfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
        struct file *file = iocb->ki_filp;
        loff_t pos = *(&iocb->ki_pos);
-       unsigned long nr_segs = iter->nr_segs;
        ssize_t rc;
 
        BUG_ON(iocb->private);
@@ -482,8 +470,7 @@ static ssize_t pvfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
        rc = do_readv_writev(PVFS_IO_WRITE,
                             file,
                             &pos,
-                            iter->iov,
-                            nr_segs);
+                            iter);
        if (rc < 0) {
                gossip_err("%s: do_readv_writev failed, rc:%zd:.\n",
                           __func__, rc);