1 files changed, 161 insertions, 109 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 513c12cf444c..33a09da16c9c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -95,7 +95,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
         struct inode *inode = file_inode(iocb->ki_filp);
         struct mutex *aio_mutex = NULL;
         struct blk_plug plug;
-        int o_direct = file->f_flags & O_DIRECT;
+        int o_direct = io_is_direct(file);
         int overwrite = 0;
         size_t length = iov_iter_count(from);
         ssize_t ret;
@@ -191,17 +191,41 @@ errout:
         return ret;
 }
 
+#ifdef CONFIG_FS_DAX
+static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        return dax_fault(vma, vmf, ext4_get_block);
+                                        /* Is this the right get_block? */
+}
+
+static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        return dax_mkwrite(vma, vmf, ext4_get_block);
+}
+
+static const struct vm_operations_struct ext4_dax_vm_ops = {
+        .fault          = ext4_dax_fault,
+        .page_mkwrite   = ext4_dax_mkwrite,
+};
+#else
+#define ext4_dax_vm_ops ext4_file_vm_ops
+#endif
+
 static const struct vm_operations_struct ext4_file_vm_ops = {
         .fault          = filemap_fault,
         .map_pages      = filemap_map_pages,
         .page_mkwrite   = ext4_page_mkwrite,
-        .remap_pages    = generic_file_remap_pages,
 };
 
 static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
         file_accessed(file);
-        vma->vm_ops = &ext4_file_vm_ops;
+        if (IS_DAX(file_inode(file))) {
+                vma->vm_ops = &ext4_dax_vm_ops;
+                vma->vm_flags |= VM_MIXEDMAP;
+        } else {
+                vma->vm_ops = &ext4_file_vm_ops;
+        }
         return 0;
 }
 
@@ -273,19 +297,24 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
  * we determine this extent as a data or a hole according to whether the
  * page cache has data or not.
  */
-static int ext4_find_unwritten_pgoff(struct inode *inode, int whence,
-                                     loff_t endoff, loff_t *offset)
+static int ext4_find_unwritten_pgoff(struct inode *inode,
+                                     int whence,
+                                     struct ext4_map_blocks *map,
+                                     loff_t *offset)
 {
         struct pagevec pvec;
+        unsigned int blkbits;
         pgoff_t index;
         pgoff_t end;
+        loff_t endoff;
         loff_t startoff;
         loff_t lastoff;
         int found = 0;
 
+        blkbits = inode->i_sb->s_blocksize_bits;
         startoff = *offset;
         lastoff = startoff;
-
+        endoff = (loff_t)(map->m_lblk + map->m_len) << blkbits;
 
         index = startoff >> PAGE_CACHE_SHIFT;
         end = endoff >> PAGE_CACHE_SHIFT;
@@ -403,144 +432,147 @@ out:
 static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
 {
         struct inode *inode = file->f_mapping->host;
-        struct fiemap_extent_info fie;
-        struct fiemap_extent ext[2];
-        loff_t next;
-        int i, ret = 0;
+        struct ext4_map_blocks map;
+        struct extent_status es;
+        ext4_lblk_t start, last, end;
+        loff_t dataoff, isize;
+        int blkbits;
+        int ret = 0;
 
         mutex_lock(&inode->i_mutex);
-        if (offset >= inode->i_size) {
+
+        isize = i_size_read(inode);
+        if (offset >= isize) {
                 mutex_unlock(&inode->i_mutex);
                 return -ENXIO;
         }
-        fie.fi_flags = 0;
-        fie.fi_extents_max = 2;
-        fie.fi_extents_start = (struct fiemap_extent __user *) &ext;
-        while (1) {
-                mm_segment_t old_fs = get_fs();
-
-                fie.fi_extents_mapped = 0;
-                memset(ext, 0, sizeof(*ext) * fie.fi_extents_max);
-
-                set_fs(get_ds());
-                ret = ext4_fiemap(inode, &fie, offset, maxsize - offset);
-                set_fs(old_fs);
-                if (ret)
+
+        blkbits = inode->i_sb->s_blocksize_bits;
+        start = offset >> blkbits;
+        last = start;
+        end = isize >> blkbits;
+        dataoff = offset;
+
+        do {
+                map.m_lblk = last;
+                map.m_len = end - last + 1;
+                ret = ext4_map_blocks(NULL, inode, &map, 0);
+                if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
+                        if (last != start)
+                                dataoff = (loff_t)last << blkbits;
                         break;
+                }
 
-                /* No extents found, EOF */
-                if (!fie.fi_extents_mapped) {
-                        ret = -ENXIO;
+                /*
+                 * If there is a delay extent at this offset,
+                 * it will be as a data.
+                 */
+                ext4_es_find_delayed_extent_range(inode, last, last, &es);
+                if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
+                        if (last != start)
+                                dataoff = (loff_t)last << blkbits;
                         break;
                 }
-                for (i = 0; i < fie.fi_extents_mapped; i++) {
-                        next = (loff_t)(ext[i].fe_length + ext[i].fe_logical);
 
-                        if (offset < (loff_t)ext[i].fe_logical)
-                                offset = (loff_t)ext[i].fe_logical;
-                        /*
-                         * If extent is not unwritten, then it contains valid
-                         * data, mapped or delayed.
-                         */
-                        if (!(ext[i].fe_flags & FIEMAP_EXTENT_UNWRITTEN))
-                                goto out;
+                /*
+                 * If there is a unwritten extent at this offset,
+                 * it will be as a data or a hole according to page
+                 * cache that has data or not.
+                 */
+                if (map.m_flags & EXT4_MAP_UNWRITTEN) {
+                        int unwritten;
+                        unwritten = ext4_find_unwritten_pgoff(inode, SEEK_DATA,
+                                                              &map, &dataoff);
+                        if (unwritten)
+                                break;
+                }
 
-                        /*
-                         * If there is a unwritten extent at this offset,
-                         * it will be as a data or a hole according to page
-                         * cache that has data or not.
-                         */
-                        if (ext4_find_unwritten_pgoff(inode, SEEK_DATA,
-                                                      next, &offset))
-                                goto out;
+                last++;
+                dataoff = (loff_t)last << blkbits;
+        } while (last <= end);
 
-                        if (ext[i].fe_flags & FIEMAP_EXTENT_LAST) {
-                                ret = -ENXIO;
-                                goto out;
-                        }
-                        offset = next;
-                }
-        }
-        if (offset > inode->i_size)
-                offset = inode->i_size;
-out:
         mutex_unlock(&inode->i_mutex);
-        if (ret)
-                return ret;
 
-        return vfs_setpos(file, offset, maxsize);
+        if (dataoff > isize)
+                return -ENXIO;
+
+        return vfs_setpos(file, dataoff, maxsize);
 }
 
 /*
- * ext4_seek_hole() retrieves the offset for SEEK_HOLE
+ * ext4_seek_hole() retrieves the offset for SEEK_HOLE.
  */
 static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
 {
         struct inode *inode = file->f_mapping->host;
-        struct fiemap_extent_info fie;
-        struct fiemap_extent ext[2];
-        loff_t next;
-        int i, ret = 0;
+        struct ext4_map_blocks map;
+        struct extent_status es;
+        ext4_lblk_t start, last, end;
+        loff_t holeoff, isize;
+        int blkbits;
+        int ret = 0;
 
         mutex_lock(&inode->i_mutex);
-        if (offset >= inode->i_size) {
+
+        isize = i_size_read(inode);
+        if (offset >= isize) {
                 mutex_unlock(&inode->i_mutex);
                 return -ENXIO;
         }
 
-        fie.fi_flags = 0;
-        fie.fi_extents_max = 2;
-        fie.fi_extents_start = (struct fiemap_extent __user *)&ext;
-        while (1) {
-                mm_segment_t old_fs = get_fs();
+        blkbits = inode->i_sb->s_blocksize_bits;
+        start = offset >> blkbits;
+        last = start;
+        end = isize >> blkbits;
+        holeoff = offset;
 
-                fie.fi_extents_mapped = 0;
-                memset(ext, 0, sizeof(*ext));
-
-                set_fs(get_ds());
-                ret = ext4_fiemap(inode, &fie, offset, maxsize - offset);
-                set_fs(old_fs);
-                if (ret)
-                        break;
+        do {
+                map.m_lblk = last;
+                map.m_len = end - last + 1;
+                ret = ext4_map_blocks(NULL, inode, &map, 0);
+                if (ret > 0 && !(map.m_flags & EXT4_MAP_UNWRITTEN)) {
+                        last += ret;
+                        holeoff = (loff_t)last << blkbits;
+                        continue;
+                }
 
-                /* No extents found */
-                if (!fie.fi_extents_mapped)
-                        break;
+                /*
+                 * If there is a delay extent at this offset,
+                 * we will skip this extent.
+                 */
+                ext4_es_find_delayed_extent_range(inode, last, last, &es);
+                if (es.es_len != 0 && in_range(last, es.es_lblk, es.es_len)) {
+                        last = es.es_lblk + es.es_len;
+                        holeoff = (loff_t)last << blkbits;
+                        continue;
+                }
 
-                for (i = 0; i < fie.fi_extents_mapped; i++) {
-                        next = (loff_t)(ext[i].fe_logical + ext[i].fe_length);
-                        /*
-                         * If extent is not unwritten, then it contains valid
-                         * data, mapped or delayed.
-                         */
-                        if (!(ext[i].fe_flags & FIEMAP_EXTENT_UNWRITTEN)) {
-                                if (offset < (loff_t)ext[i].fe_logical)
-                                        goto out;
-                                offset = next;
+                /*
+                 * If there is a unwritten extent at this offset,
+                 * it will be as a data or a hole according to page
+                 * cache that has data or not.
+                 */
+                if (map.m_flags & EXT4_MAP_UNWRITTEN) {
+                        int unwritten;
+                        unwritten = ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
+                                                              &map, &holeoff);
+                        if (!unwritten) {
+                                last += ret;
+                                holeoff = (loff_t)last << blkbits;
                                 continue;
                         }
-                        /*
-                         * If there is a unwritten extent at this offset,
-                         * it will be as a data or a hole according to page
-                         * cache that has data or not.
-                         */
-                        if (ext4_find_unwritten_pgoff(inode, SEEK_HOLE,
-                                                      next, &offset))
-                                goto out;
-
-                        offset = next;
-                        if (ext[i].fe_flags & FIEMAP_EXTENT_LAST)
-                                goto out;
                 }
-        }
-        if (offset > inode->i_size)
-                offset = inode->i_size;
-out:
+
+                /* find a hole */
+                break;
+        } while (last <= end);
+
         mutex_unlock(&inode->i_mutex);
-        if (ret)
-                return ret;
 
-        return vfs_setpos(file, offset, maxsize);
+        if (holeoff > isize)
+                holeoff = isize;
+
+        return vfs_setpos(file, holeoff, maxsize);
 }
 
 /*
@@ -592,6 +624,26 @@ const struct file_operations ext4_file_operations = {
         .fallocate      = ext4_fallocate,
 };
 
+#ifdef CONFIG_FS_DAX
+const struct file_operations ext4_dax_file_operations = {
+        .llseek         = ext4_llseek,
+        .read           = new_sync_read,
+        .write          = new_sync_write,
+        .read_iter      = generic_file_read_iter,
+        .write_iter     = ext4_file_write_iter,
+        .unlocked_ioctl = ext4_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl   = ext4_compat_ioctl,
+#endif
+        .mmap           = ext4_file_mmap,
+        .open           = ext4_file_open,
+        .release        = ext4_release_file,
+        .fsync          = ext4_sync_file,
+        /* Splice not yet supported with DAX */
+        .fallocate      = ext4_fallocate,
+};
+#endif
+
 const struct inode_operations ext4_file_inode_operations = {
         .setattr        = ext4_setattr,
         .getattr        = ext4_getattr,