30 files changed, 117 insertions, 126 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index eba790134253..9b0d5a33c8bf 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -196,8 +196,7 @@ prototypes:
         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
         int (*releasepage) (struct page *, int);
         void (*freepage)(struct page *);
-        int (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs);
+        int (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
         int (*get_xip_mem)(struct address_space *, pgoff_t, int, void **,
                                 unsigned long *);
         int (*migratepage)(struct address_space *, struct page *, struct page *);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 617f6d70c077..1846374a5add 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -589,8 +589,7 @@ struct address_space_operations {
         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
         int (*releasepage) (struct page *, int);
         void (*freepage)(struct page *);
-        ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs);
+        ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
         struct page* (*get_xip_page)(struct address_space *, sector_t,
                         int);
         /* migrate the contents of a page to the specified target */
diff --git a/drivers/staging/lustre/lustre/llite/rw26.c b/drivers/staging/lustre/lustre/llite/rw26.c
index 7e3e0967993b..66e05c6f4d27 100644
--- a/drivers/staging/lustre/lustre/llite/rw26.c
+++ b/drivers/staging/lustre/lustre/llite/rw26.c
@@ -363,15 +363,14 @@ static ssize_t ll_direct_IO_26_seg(const struct lu_env *env, struct cl_io *io,
 #define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_CACHE_SIZE) & \
                       ~(DT_MAX_BRW_SIZE - 1))
 static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
-                               const struct iovec *iov, loff_t file_offset,
-                               unsigned long nr_segs)
+                               struct iov_iter *iter, loff_t file_offset)
 {
         struct lu_env *env;
         struct cl_io *io;
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
         struct ccc_object *obj = cl_inode2ccc(inode);
-        long count = iov_length(iov, nr_segs);
+        long count = iov_length(iter->iov, iter->nr_segs);
         long tot_bytes = 0, result = 0;
         struct ll_inode_info *lli = ll_i2info(inode);
         unsigned long seg = 0;
@@ -392,9 +391,9 @@ static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
                MAX_DIO_SIZE >> PAGE_CACHE_SHIFT);
 
         /* Check that all user buffers are aligned as well */
-        for (seg = 0; seg < nr_segs; seg++) {
-                if (((unsigned long)iov[seg].iov_base & ~CFS_PAGE_MASK) ||
-                    (iov[seg].iov_len & ~CFS_PAGE_MASK))
+        for (seg = 0; seg < iter->nr_segs; seg++) {
+                if (((unsigned long)iter->iov[seg].iov_base & ~CFS_PAGE_MASK) ||
+                    (iter->iov[seg].iov_len & ~CFS_PAGE_MASK))
                         return -EINVAL;
         }
 
@@ -411,9 +410,9 @@ static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
                 mutex_lock(&inode->i_mutex);
 
         LASSERT(obj->cob_transient_pages == 0);
-        for (seg = 0; seg < nr_segs; seg++) {
-                long iov_left = iov[seg].iov_len;
-                unsigned long user_addr = (unsigned long)iov[seg].iov_base;
+        for (seg = 0; seg < iter->nr_segs; seg++) {
+                long iov_left = iter->iov[seg].iov_len;
+                unsigned long user_addr = (unsigned long)iter->iov[seg].iov_base;
 
                 if (rw == READ) {
                         if (file_offset >= i_size_read(inode))
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index c71e88602ff4..cc1cfae726b3 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -259,8 +259,7 @@ static int v9fs_launder_page(struct page *page)
  *
  */
 static ssize_t
-v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-               loff_t pos, unsigned long nr_segs)
+v9fs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
         /*
          * FIXME
@@ -269,7 +268,7 @@ v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
          */
         p9_debug(P9_DEBUG_VFS, "v9fs_direct_IO: v9fs_direct_IO (%s) off/no(%lld/%lu) EINVAL\n",
                  iocb->ki_filp->f_path.dentry->d_name.name,
-                 (long long)pos, nr_segs);
+                 (long long)pos, iter->nr_segs);
 
         return -EINVAL;
 }
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 552a8d13bc32..938fc707d769 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -165,14 +165,15 @@ blkdev_get_block(struct inode *inode, sector_t iblock,
 }
 
 static ssize_t
-blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs)
+blkdev_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
+                        loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
 
-        return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iov, offset,
-                                    nr_segs, blkdev_get_block, NULL, NULL, 0);
+        return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iter->iov,
+                                    offset, iter->nr_segs, blkdev_get_block,
+                                    NULL, NULL, 0);
 }
 
 int __sync_blockdev(struct block_device *bdev, int wait)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5f805bc944fa..30a6cc51f32c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7433,8 +7433,7 @@ out:
 }
 
 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
-                        const struct iovec *iov, loff_t offset,
-                        unsigned long nr_segs)
+                        struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
@@ -7444,8 +7443,8 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
         bool relock = false;
         ssize_t ret;
 
-        if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
-                            offset, nr_segs))
+        if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iter->iov,
+                            offset, iter->nr_segs))
                 return 0;
 
         atomic_inc(&inode->i_dio_count);
@@ -7457,7 +7456,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
          * we need to flush the dirty pages again to make absolutely sure
          * that any outstanding dirty pages are on disk.
          */
-        count = iov_length(iov, nr_segs);
+        count = iov_length(iter->iov, iter->nr_segs);
         if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
                      &BTRFS_I(inode)->runtime_flags))
                 filemap_fdatawrite_range(inode->i_mapping, offset, count);
@@ -7484,7 +7483,8 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
 
         ret = __blockdev_direct_IO(rw, iocb, inode,
                         BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
-                        iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
+                        iter->iov, offset, iter->nr_segs,
+                        btrfs_get_blocks_direct, NULL,
                         btrfs_submit_direct, flags);
         if (rw & WRITE) {
                 if (ret < 0 && ret != -EIOCBQUEUED)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index b53278c9fd97..342ca5e423f9 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1187,8 +1187,8 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
  * never get called.
  */
 static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
-                              const struct iovec *iov,
-                              loff_t pos, unsigned long nr_segs)
+                              struct iov_iter *iter,
+                              loff_t pos)
 {
         WARN_ON(1);
         return -EINVAL;
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2900d150654e..a4ccc39e6c11 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -3702,8 +3702,8 @@ void cifs_oplock_break(struct work_struct *work)
  * Direct IO is not yet supported in the cached mode. 
  */
 static ssize_t
-cifs_direct_io(int rw, struct kiocb *iocb, const struct iovec *iov,
-               loff_t pos, unsigned long nr_segs)
+cifs_direct_io(int rw, struct kiocb *iocb, struct iov_iter *iter,
+               loff_t pos)
 {
         /*
          * FIXME
diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
index d1c244d67667..3f9cafd73931 100644
--- a/fs/exofs/inode.c
+++ b/fs/exofs/inode.c
@@ -964,7 +964,7 @@ static void exofs_invalidatepage(struct page *page, unsigned int offset,
 
  /* TODO: Should be easy enough to do proprly */
 static ssize_t exofs_direct_IO(int rw, struct kiocb *iocb,
-                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+                struct iov_iter *iter, loff_t offset)
 {
         return 0;
 }
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index b1d2a4675d42..47fbe760a7f8 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -850,18 +850,19 @@ static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
 }
 
 static ssize_t
-ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs)
+ext2_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
+                        loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                 ext2_get_block);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, ext2_get_block);
         if (ret < 0 && (rw & WRITE))
-                ext2_write_failed(mapping, offset + iov_length(iov, nr_segs));
+                ext2_write_failed(mapping, offset +
+                                  iov_length(iter->iov, iter->nr_segs));
         return ret;
 }
 
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index f5157d0d1b43..7a5c501dc31b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1820,8 +1820,7 @@ static int ext3_releasepage(struct page *page, gfp_t wait)
  * VFS code falls back into buffered path in that case so we are safe.
  */
 static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
-                        const struct iovec *iov, loff_t offset,
-                        unsigned long nr_segs)
+                        struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
@@ -1829,10 +1828,10 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
         handle_t *handle;
         ssize_t ret;
         int orphan = 0;
-        size_t count = iov_length(iov, nr_segs);
+        size_t count = iov_length(iter->iov, iter->nr_segs);
         int retries = 0;
 
-        trace_ext3_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
+        trace_ext3_direct_IO_enter(inode, offset, count, rw);
 
         if (rw == WRITE) {
                 loff_t final_size = offset + count;
@@ -1856,15 +1855,15 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
         }
 
 retry:
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                 ext3_get_block);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, ext3_get_block);
         /*
          * In case of error extending write may have instantiated a few
          * blocks outside i_size. Trim these off again.
          */
         if (unlikely((rw & WRITE) && ret < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + count;
 
                 if (end > isize)
                         ext3_truncate_failed_direct_write(inode);
@@ -1909,8 +1908,7 @@ retry:
                         ret = err;
         }
 out:
-        trace_ext3_direct_IO_exit(inode, offset,
-                                iov_length(iov, nr_segs), rw, ret);
+        trace_ext3_direct_IO_exit(inode, offset, count, rw, ret);
         return ret;
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d7b7462a0e13..f51db730da39 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3222,8 +3222,7 @@ retake_lock:
 }
 
 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
-                              const struct iovec *iov, loff_t offset,
-                              unsigned long nr_segs)
+                              struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
@@ -3239,13 +3238,13 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
         if (ext4_has_inline_data(inode))
                 return 0;
 
-        trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
+        trace_ext4_direct_IO_enter(inode, offset, iov_length(iter->iov, iter->nr_segs), rw);
         if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
-                ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
+                ret = ext4_ext_direct_IO(rw, iocb, iter->iov, offset, iter->nr_segs);
         else
-                ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
+                ret = ext4_ind_direct_IO(rw, iocb, iter->iov, offset, iter->nr_segs);
         trace_ext4_direct_IO_exit(inode, offset,
-                                iov_length(iov, nr_segs), rw, ret);
+                                iov_length(iter->iov, iter->nr_segs), rw, ret);
         return ret;
 }
 
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 45abd60e2bff..3a6ef121c095 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1010,7 +1010,7 @@ static int check_direct_IO(struct inode *inode, int rw,
 }
 
 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
-                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+                struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
@@ -1019,11 +1019,11 @@ static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
         if (f2fs_has_inline_data(inode))
                 return 0;
 
-        if (check_direct_IO(inode, rw, iov, offset, nr_segs))
+        if (check_direct_IO(inode, rw, iter->iov, offset, iter->nr_segs))
                 return 0;
 
-        return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                                        get_data_block);
+        return blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                  iter->nr_segs, get_data_block);
 }
 
 static void f2fs_invalidate_data_page(struct page *page, unsigned int offset,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index b3361fe2bcb5..d5237a199055 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -185,8 +185,8 @@ static int fat_write_end(struct file *file, struct address_space *mapping,
 }
 
 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
-                             const struct iovec *iov,
-                             loff_t offset, unsigned long nr_segs)
+                             struct iov_iter *iter,
+                             loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
@@ -203,7 +203,7 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
                  *
                  * Return 0, and fallback to normal buffered write.
                  */
-                loff_t size = offset + iov_length(iov, nr_segs);
+                loff_t size = offset + iov_length(iter->iov, iter->nr_segs);
                 if (MSDOS_I(inode)->mmu_private < size)
                         return 0;
         }
@@ -212,10 +212,11 @@ static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
          * FAT need to use the DIO_LOCKING for avoiding the race
          * condition of fat_get_block() and ->truncate().
          */
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                 fat_get_block);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, fat_get_block);
         if (ret < 0 && (rw & WRITE))
-                fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
+                fat_write_failed(mapping, offset +
+                                 iov_length(iter->iov, iter->nr_segs));
 
         return ret;
 }
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 9c7f346879e7..17d96f36df15 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2890,8 +2890,8 @@ static inline loff_t fuse_round_up(loff_t off)
 }
 
 static ssize_t
-fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs)
+fuse_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
+                        loff_t offset)
 {
         ssize_t ret = 0;
         struct file *file = iocb->ki_filp;
@@ -2900,7 +2900,7 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
         loff_t pos = 0;
         struct inode *inode;
         loff_t i_size;
-        size_t count = iov_length(iov, nr_segs);
+        size_t count = iov_length(iter->iov, iter->nr_segs);
         struct fuse_io_priv *io;
 
         pos = offset;
@@ -2944,9 +2944,9 @@ fuse_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
                 io->async = false;
 
         if (rw == WRITE)
-                ret = __fuse_direct_write(io, iov, nr_segs, &pos);
+                ret = __fuse_direct_write(io, iter->iov, iter->nr_segs, &pos);
         else
-                ret = __fuse_direct_read(io, iov, nr_segs, &pos, count);
+                ret = __fuse_direct_read(io, iter->iov, iter->nr_segs, &pos, count);
 
         if (io->async) {
                 fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index ce62dcac90b6..e84ddaa42104 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -1041,8 +1041,7 @@ static int gfs2_ok_for_dio(struct gfs2_inode *ip, int rw, loff_t offset)
 
 
 static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
-                              const struct iovec *iov, loff_t offset,
-                              unsigned long nr_segs)
+                              struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
@@ -1082,7 +1081,7 @@ static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
          */
         if (mapping->nrpages) {
                 loff_t lstart = offset & (PAGE_CACHE_SIZE - 1);
-                loff_t len = iov_length(iov, nr_segs);
+                loff_t len = iov_length(iter->iov, iter->nr_segs);
                 loff_t end = PAGE_ALIGN(offset + len) - 1;
 
                 rv = 0;
@@ -1097,9 +1096,9 @@ static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
                         truncate_inode_pages_range(mapping, lstart, end);
         }
 
-        rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
-                                  offset, nr_segs, gfs2_get_block_direct,
-                                  NULL, NULL, 0);
+        rv = __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
+                                  iter->iov, offset, iter->nr_segs,
+                                  gfs2_get_block_direct, NULL, NULL, 0);
 out:
         gfs2_glock_dq(&gh);
         gfs2_holder_uninit(&gh);
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 9e2fecd62f62..09cff13528c5 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -125,15 +125,15 @@ static int hfs_releasepage(struct page *page, gfp_t mask)
 }
 
 static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
-                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+                struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = file_inode(file)->i_mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                 hfs_get_block);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, hfs_get_block);
 
         /*
          * In case of error extending write may have instantiated a few
@@ -141,7 +141,7 @@ static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
          */
         if (unlikely((rw & WRITE) && ret < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
                 if (end > isize)
                         hfs_write_failed(mapping, end);
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index a4f45bd88a63..7f894a5b5eaf 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -123,14 +123,14 @@ static int hfsplus_releasepage(struct page *page, gfp_t mask)
 }
 
 static ssize_t hfsplus_direct_IO(int rw, struct kiocb *iocb,
-                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+                struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = file_inode(file)->i_mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset, iter->nr_segs,
                                  hfsplus_get_block);
 
         /*
@@ -139,7 +139,7 @@ static ssize_t hfsplus_direct_IO(int rw, struct kiocb *iocb,
          */
         if (unlikely((rw & WRITE) && ret < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
                 if (end > isize)
                         hfsplus_write_failed(mapping, end);
diff --git a/fs/jfs/inode.c b/fs/jfs/inode.c
index 6f8fe72c2a7a..7052744d5107 100644
--- a/fs/jfs/inode.c
+++ b/fs/jfs/inode.c
@@ -331,15 +331,15 @@ static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
 }
 
 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
-        const struct iovec *iov, loff_t offset, unsigned long nr_segs)
+        struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = file->f_mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                 jfs_get_block);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, jfs_get_block);
 
         /*
          * In case of error extending write may have instantiated a few
@@ -347,7 +347,7 @@ static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
          */
         if (unlikely((rw & WRITE) && ret < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
                 if (end > isize)
                         jfs_write_failed(mapping, end);
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index b8797ae6831f..e9cde3935001 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -121,20 +121,20 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
  * shunt off direct read and write requests before the VFS gets them,
  * so this method is only ever called for swap.
  */
-ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs)
+ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 #ifndef CONFIG_NFS_SWAP
         dprintk("NFS: nfs_direct_IO (%pD) off/no(%Ld/%lu) EINVAL\n",
-                        iocb->ki_filp, (long long) pos, nr_segs);
+                        iocb->ki_filp, (long long) pos, iter->nr_segs);
 
         return -EINVAL;
 #else
         VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
 
         if (rw == READ || rw == KERNEL_READ)
-                return nfs_file_direct_read(iocb, iov, nr_segs, pos,
+                return nfs_file_direct_read(iocb, iter->iov, iter->nr_segs, pos,
                                 rw == READ ? true : false);
-        return nfs_file_direct_write(iocb, iov, nr_segs, pos,
+        return nfs_file_direct_write(iocb, iter->iov, iter->nr_segs, pos,
                                 rw == WRITE ? true : false);
 #endif /* CONFIG_NFS_SWAP */
 }
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index b9c5726120e3..1c0e8fedc095 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -298,8 +298,8 @@ static int nilfs_write_end(struct file *file, struct address_space *mapping,
 }
 
 static ssize_t
-nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
-                loff_t offset, unsigned long nr_segs)
+nilfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
+                loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
@@ -310,8 +310,8 @@ nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
                 return 0;
 
         /* Needs synchronization with the cleaner */
-        size = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                  nilfs_get_block);
+        size = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                  iter->nr_segs, nilfs_get_block);
 
         /*
          * In case of error extending write may have instantiated a few
@@ -319,7 +319,7 @@ nilfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
          */
         if (unlikely((rw & WRITE) && size < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
                 if (end > isize)
                         nilfs_write_failed(mapping, end);
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index d310d12a9adc..799fd0afcb35 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -599,9 +599,8 @@ static int ocfs2_releasepage(struct page *page, gfp_t wait)
 
 static ssize_t ocfs2_direct_IO(int rw,
                                struct kiocb *iocb,
-                               const struct iovec *iov,
-                               loff_t offset,
-                               unsigned long nr_segs)
+                               struct iov_iter *iter,
+                               loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file_inode(file)->i_mapping->host;
@@ -618,7 +617,7 @@ static ssize_t ocfs2_direct_IO(int rw,
                 return 0;
 
         return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
-                                    iov, offset, nr_segs,
+                                    iter->iov, offset, iter->nr_segs,
                                     ocfs2_direct_IO_get_blocks,
                                     ocfs2_dio_end_io, NULL, 0);
 }
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index bc8b8009897d..17bf4c41a509 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -3083,15 +3083,14 @@ static int reiserfs_releasepage(struct page *page, gfp_t unused_gfp_flags)
 /* We thank Mingming Cao for helping us understand in great detail what
    to do in this section of the code. */
 static ssize_t reiserfs_direct_IO(int rw, struct kiocb *iocb,
-                                  const struct iovec *iov, loff_t offset,
-                                  unsigned long nr_segs)
+                                  struct iov_iter *iter, loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct inode *inode = file->f_mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
-                                  reiserfs_get_blocks_direct_io);
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset,
+                                 iter->nr_segs, reiserfs_get_blocks_direct_io);
 
         /*
          * In case of error extending write may have instantiated a few
@@ -3099,7 +3098,7 @@ static ssize_t reiserfs_direct_IO(int rw, struct kiocb *iocb,
          */
         if (unlikely((rw & WRITE) && ret < 0)) {
                 loff_t isize = i_size_read(inode);
-                loff_t end = offset + iov_length(iov, nr_segs);
+                loff_t end = offset + iov_length(iter->iov, iter->nr_segs);
 
                 if ((end > isize) && inode_newsize_ok(inode, isize) == 0) {
                         truncate_setsize(inode, isize);
diff --git a/fs/udf/file.c b/fs/udf/file.c
index d2c170f8b035..ade886401658 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -119,8 +119,8 @@ static int udf_adinicb_write_end(struct file *file,
 }
 
 static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb,
-                                     const struct iovec *iov,
-                                     loff_t offset, unsigned long nr_segs)
+                                     struct iov_iter *iter,
+                                     loff_t offset)
 {
         /* Fallback to buffered I/O. */
         return 0;
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 5d643706212f..5b184c7f7dcb 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -217,18 +217,18 @@ static int udf_write_begin(struct file *file, struct address_space *mapping,
 }
 
 static ssize_t udf_direct_IO(int rw, struct kiocb *iocb,
-                             const struct iovec *iov,
-                             loff_t offset, unsigned long nr_segs)
+                             struct iov_iter *iter,
+                             loff_t offset)
 {
         struct file *file = iocb->ki_filp;
         struct address_space *mapping = file->f_mapping;
         struct inode *inode = mapping->host;
         ssize_t ret;
 
-        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
+        ret = blockdev_direct_IO(rw, iocb, inode, iter->iov, offset, iter->nr_segs,
                                   udf_get_block);
         if (unlikely(ret < 0 && (rw & WRITE)))
-                udf_write_failed(mapping, offset + iov_length(iov, nr_segs));
+                udf_write_failed(mapping, offset + iov_length(iter->iov, iter->nr_segs));
         return ret;
 }
 
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 0479c32c5eb1..330d7b1c4be3 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1449,9 +1449,8 @@ STATIC ssize_t
 xfs_vm_direct_IO(
         int                     rw,
         struct kiocb            *iocb,
-        const struct iovec      *iov,
-        loff_t                  offset,
-        unsigned long           nr_segs)
+        struct iov_iter         *iter,
+        loff_t                  offset)
 {
         struct inode            *inode = iocb->ki_filp->f_mapping->host;
         struct block_device     *bdev = xfs_find_bdev_for_inode(inode);
@@ -1459,7 +1458,7 @@ xfs_vm_direct_IO(
         ssize_t                 ret;
 
         if (rw & WRITE) {
-                size_t size = iov_length(iov, nr_segs);
+                size_t size = iov_length(iter->iov, iter->nr_segs);
 
                 /*
                  * We cannot preallocate a size update transaction here as we
@@ -1471,16 +1470,16 @@ xfs_vm_direct_IO(
                 if (offset + size > XFS_I(inode)->i_d.di_size)
                         ioend->io_isdirect = 1;
 
-                ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
-                                            offset, nr_segs,
+                ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iter->iov,
+                                            offset, iter->nr_segs,
                                             xfs_get_blocks_direct,
                                             xfs_end_io_direct_write, NULL,
                                             DIO_ASYNC_EXTEND);
                 if (ret != -EIOCBQUEUED && iocb->private)
                         goto out_destroy_ioend;
         } else {
-                ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
-                                            offset, nr_segs,
+                ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iter->iov,
+                                            offset, iter->nr_segs,
                                             xfs_get_blocks_direct,
                                             NULL, NULL, 0);
         }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 796de742fe4a..399a338c92b5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -343,8 +343,7 @@ struct address_space_operations {
         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
         int (*releasepage) (struct page *, gfp_t);
         void (*freepage)(struct page *);
-        ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
-                        loff_t offset, unsigned long nr_segs);
+        ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
         int (*get_xip_mem)(struct address_space *, pgoff_t, int,
                                                 void **, unsigned long *);
         /*
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index fa6918b0f829..5a0d78ec739d 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -459,8 +459,7 @@ extern int nfs3_removexattr (struct dentry *, const char *name);
 /*
  * linux/fs/nfs/direct.c
  */
-extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
-                        unsigned long);
+extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
 extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
                         const struct iovec *iov, unsigned long nr_segs,
                         loff_t pos, bool uio);
diff --git a/mm/filemap.c b/mm/filemap.c
index 7c1417b0bd7b..139641274f1e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1699,10 +1699,9 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
                 size = i_size_read(inode);
                 retval = filemap_write_and_wait_range(mapping, pos,
                                         pos + iov_length(iov, nr_segs) - 1);
-                if (!retval) {
-                        retval = mapping->a_ops->direct_IO(READ, iocb,
-                                                           iov, pos, nr_segs);
-                }
+                if (!retval)
+                        retval = mapping->a_ops->direct_IO(READ, iocb, &i, pos);
+
                 if (retval > 0) {
                         *ppos = pos + retval;
                         count -= retval;
@@ -2383,7 +2382,7 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
                 }
         }
 
-        written = mapping->a_ops->direct_IO(WRITE, iocb, from->iov, pos, from->nr_segs);
+        written = mapping->a_ops->direct_IO(WRITE, iocb, from, pos);
 
         /*
          * Finally, try again to invalidate clean pages which might have been
diff --git a/mm/page_io.c b/mm/page_io.c
index 7c59ef681381..0ed0644c73db 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -263,16 +263,18 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
                         .iov_base = kmap(page),
                         .iov_len  = PAGE_SIZE,
                 };
+                struct iov_iter from;
 
                 init_sync_kiocb(&kiocb, swap_file);
                 kiocb.ki_pos = page_file_offset(page);
                 kiocb.ki_nbytes = PAGE_SIZE;
+                iov_iter_init(&from, &iov, 1, PAGE_SIZE, 0);
 
                 set_page_writeback(page);
                 unlock_page(page);
                 ret = mapping->a_ops->direct_IO(KERNEL_WRITE,
-                                                &kiocb, &iov,
-                                                kiocb.ki_pos, 1);
+                                                &kiocb, &from,
+                                                kiocb.ki_pos);
                 kunmap(page);
                 if (ret == PAGE_SIZE) {
                         count_vm_event(PSWPOUT);