55 files changed, 691 insertions, 861 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 7c3f187d48bf..0a926e2ba3ab 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -196,7 +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 *, struct iov_iter *iter, loff_t offset);
+        int (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
         int (*migratepage)(struct address_space *, struct page *, struct page *);
         int (*launder_page)(struct page *);
         int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 207cdca68bed..5d833b32bbcd 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -590,7 +590,7 @@ 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 *, struct iov_iter *iter, loff_t offset);
+        ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
         /* migrate the contents of a page to the specified target */
         int (*migratepage) (struct page *, struct page *);
         int (*launder_page) (struct page *);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index c4fd1e45ce1e..ae3fcb4199e9 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -88,28 +88,6 @@ static int part_shift;
 
 static struct workqueue_struct *loop_wq;
 
-/*
- * Transfer functions
- */
-static int transfer_none(struct loop_device *lo, int cmd,
-                         struct page *raw_page, unsigned raw_off,
-                         struct page *loop_page, unsigned loop_off,
-                         int size, sector_t real_block)
-{
-        char *raw_buf = kmap_atomic(raw_page) + raw_off;
-        char *loop_buf = kmap_atomic(loop_page) + loop_off;
-
-        if (cmd == READ)
-                memcpy(loop_buf, raw_buf, size);
-        else
-                memcpy(raw_buf, loop_buf, size);
-
-        kunmap_atomic(loop_buf);
-        kunmap_atomic(raw_buf);
-        cond_resched();
-        return 0;
-}
-
 static int transfer_xor(struct loop_device *lo, int cmd,
                         struct page *raw_page, unsigned raw_off,
                         struct page *loop_page, unsigned loop_off,
@@ -148,14 +126,13 @@ static int xor_init(struct loop_device *lo, const struct loop_info64 *info)
 
 static struct loop_func_table none_funcs = {
         .number = LO_CRYPT_NONE,
-        .transfer = transfer_none,
-};      
+}; 
 
 static struct loop_func_table xor_funcs = {
         .number = LO_CRYPT_XOR,
         .transfer = transfer_xor,
         .init = xor_init
-};      
+}; 
 
 /* xfer_funcs[0] is special - its release function is never called */
 static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = {
@@ -215,207 +192,169 @@ lo_do_transfer(struct loop_device *lo, int cmd,
                struct page *lpage, unsigned loffs,
                int size, sector_t rblock)
 {
-        if (unlikely(!lo->transfer))
+        int ret;
+
+        ret = lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock);
+        if (likely(!ret))
                 return 0;
 
-        return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock);
+        printk_ratelimited(KERN_ERR
+                "loop: Transfer error at byte offset %llu, length %i.\n",
+                (unsigned long long)rblock << 9, size);
+        return ret;
 }
 
-/**
- * __do_lo_send_write - helper for writing data to a loop device
- *
- * This helper just factors out common code between do_lo_send_direct_write()
- * and do_lo_send_write().
- */
-static int __do_lo_send_write(struct file *file,
-                u8 *buf, const int len, loff_t pos)
+static int lo_write_bvec(struct file *file, struct bio_vec *bvec, loff_t *ppos)
 {
-        struct kvec kvec = {.iov_base = buf, .iov_len = len};
-        struct iov_iter from;
+        struct iov_iter i;
         ssize_t bw;
 
-        iov_iter_kvec(&from, ITER_KVEC | WRITE, &kvec, 1, len);
+        iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len);
 
         file_start_write(file);
-        bw = vfs_iter_write(file, &from, &pos);
+        bw = vfs_iter_write(file, &i, ppos);
         file_end_write(file);
-        if (likely(bw == len))
+
+        if (likely(bw ==  bvec->bv_len))
                 return 0;
-        printk_ratelimited(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n",
+