1 files changed, 81 insertions, 19 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index d5c7d09919f3..c7dbb4661119 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -32,6 +32,7 @@
 #include <linux/buffer_head.h>
 #include <linux/mpage.h>
 #include <linux/fiemap.h>
+#include <linux/iomap.h>
 #include <linux/namei.h>
 #include <linux/uio.h>
 #include "ext2.h"
@@ -618,7 +619,7 @@ static void ext2_splice_branch(struct inode *inode,
  */
 static int ext2_get_blocks(struct inode *inode,
                            sector_t iblock, unsigned long maxblocks,
-                           struct buffer_head *bh_result,
+                           u32 *bno, bool *new, bool *boundary,
                            int create)
 {
         int err = -EIO;
@@ -644,7 +645,6 @@ static int ext2_get_blocks(struct inode *inode,
         /* Simplest case - block found, no allocation needed */
         if (!partial) {
                 first_block = le32_to_cpu(chain[depth - 1].key);
-                clear_buffer_new(bh_result); /* What's this do? */
                 count++;
                 /*map more blocks*/
                 while (count < maxblocks && count <= blocks_to_boundary) {
@@ -699,7 +699,6 @@ static int ext2_get_blocks(struct inode *inode,
                         mutex_unlock(&ei->truncate_mutex);
                         if (err)
                                 goto cleanup;
-                        clear_buffer_new(bh_result);
                         goto got_it;
                 }
         }
@@ -745,15 +744,16 @@ static int ext2_get_blocks(struct inode *inode,
                         mutex_unlock(&ei->truncate_mutex);
                         goto cleanup;
                 }
-        } else
-                set_buffer_new(bh_result);
+        } else {
+                *new = true;
+        }
 
         ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
         mutex_unlock(&ei->truncate_mutex);
 got_it:
-        map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
+        *bno = le32_to_cpu(chain[depth-1].key);
         if (count > blocks_to_boundary)
-                set_buffer_boundary(bh_result);
+                *boundary = true;
         err = count;
         /* Clean up and exit */
         partial = chain + depth - 1;    /* the whole chain */
@@ -765,19 +765,82 @@ cleanup:
         return err;
 }
 
-int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+int ext2_get_block(struct inode *inode, sector_t iblock,
+                struct buffer_head *bh_result, int create)
 {
         unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
-        int ret = ext2_get_blocks(inode, iblock, max_blocks,
-                              bh_result, create);
-        if (ret > 0) {
-                bh_result->b_size = (ret << inode->i_blkbits);
-                ret = 0;
+        bool new = false, boundary = false;
+        u32 bno;
+        int ret;
+
+        ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
+                        create);
+        if (ret <= 0)
+                return ret;
+
+        map_bh(bh_result, inode->i_sb, bno);
+        bh_result->b_size = (ret << inode->i_blkbits);
+        if (new)
+                set_buffer_new(bh_result);
+        if (boundary)
+                set_buffer_boundary(bh_result);
+        return 0;
+
+}
+
+#ifdef CONFIG_FS_DAX
+static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
+                unsigned flags, struct iomap *iomap)
+{
+        unsigned int blkbits = inode->i_blkbits;
+        unsigned long first_block = offset >> blkbits;
+        unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
+        bool new = false, boundary = false;
+        u32 bno;
+        int ret;
+
+        ret = ext2_get_blocks(inode, first_block, max_blocks,
+                        &bno, &new, &boundary, flags & IOMAP_WRITE);
+        if (ret < 0)
+                return ret;
+
+        iomap->flags = 0;
+        iomap->bdev = inode->i_sb->s_bdev;
+        iomap->offset = (u64)first_block << blkbits;
+
+        if (ret == 0) {
+                iomap->type = IOMAP_HOLE;
+                iomap->blkno = IOMAP_NULL_BLOCK;
+                iomap->length = 1 << blkbits;
+        } else {
+                iomap->type = IOMAP_MAPPED;
+                iomap->blkno = (sector_t)bno << (blkbits - 9);
+                iomap->length = (u64)ret << blkbits;
+                iomap->flags |= IOMAP_F_MERGED;
         }
-        return ret;
 
+        if (new)
+                iomap->flags |= IOMAP_F_NEW;
+        return 0;
 }
 
+static int
+ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
+                ssize_t written, unsigned flags, struct iomap *iomap)
+{
+        if (iomap->type == IOMAP_MAPPED &&
+            written < length &&
+            (flags & IOMAP_WRITE))
+                ext2_write_failed(inode->i_mapping, offset + length);
+        return 0;
+}
+
+struct iomap_ops ext2_iomap_ops = {
+        .iomap_begin            = ext2_iomap_begin,
+        .iomap_end              = ext2_iomap_end,
+};
+#endif /* CONFIG_FS_DAX */
+
 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 u64 start, u64 len)
 {
@@ -863,11 +926,10 @@ ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
         loff_t offset = iocb->ki_pos;
         ssize_t ret;
 
-        if (IS_DAX(inode))
-                ret = dax_do_io(iocb, inode, iter, ext2_get_block, NULL,
-                                DIO_LOCKING);
-        else
-                ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
+        if (WARN_ON_ONCE(IS_DAX(inode)))
+                return -EIO;
+
+        ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
         if (ret < 0 && iov_iter_rw(iter) == WRITE)
                 ext2_write_failed(mapping, offset + count);
         return ret;