iomap: switch iomap_seek_hole to use iomap_iter

Rewrite iomap_seek_hole to use iomap_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/fs/iomap/seek.c b/fs/iomap/seek.c
index ce6fb81..fed8f90 100644 (file)
--- a/fs/iomap/seek.c
+++ b/fs/iomap/seek.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2017 Red Hat, Inc.
- * Copyright (c) 2018 Christoph Hellwig.
+ * Copyright (c) 2018-2021 Christoph Hellwig.
  */
 #include <linux/module.h>
 #include <linux/compiler.h>
@@ -10,21 +10,20 @@
 #include <linux/pagemap.h>
 #include <linux/pagevec.h>
 
-static loff_t
-iomap_seek_hole_actor(struct inode *inode, loff_t start, loff_t length,
-                     void *data, struct iomap *iomap, struct iomap *srcmap)
+static loff_t iomap_seek_hole_iter(const struct iomap_iter *iter,
+               loff_t *hole_pos)
 {
-       loff_t offset = start;
+       loff_t length = iomap_length(iter);
 
-       switch (iomap->type) {
+       switch (iter->iomap.type) {
        case IOMAP_UNWRITTEN:
-               offset = mapping_seek_hole_data(inode->i_mapping, start,
-                               start + length, SEEK_HOLE);
-               if (offset == start + length)
+               *hole_pos = mapping_seek_hole_data(iter->inode->i_mapping,
+                               iter->pos, iter->pos + length, SEEK_HOLE);
+               if (*hole_pos == iter->pos + length)
                        return length;
-               fallthrough;
+               return 0;
        case IOMAP_HOLE:
-               *(loff_t *)data = offset;
+               *hole_pos = iter->pos;
                return 0;
        default:
                return length;
@@ -32,26 +31,28 @@ iomap_seek_hole_actor(struct inode *inode, loff_t start, loff_t length,
 }
 
 loff_t
-iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
+iomap_seek_hole(struct inode *inode, loff_t pos, const struct iomap_ops *ops)
 {
        loff_t size = i_size_read(inode);
-       loff_t ret;
+       struct iomap_iter iter = {
+               .inode  = inode,
+               .pos    = pos,
+               .flags  = IOMAP_REPORT,
+       };
+       int ret;
 
        /* Nothing to be found before or beyond the end of the file. */
-       if (offset < 0 || offset >= size)
+       if (pos < 0 || pos >= size)
                return -ENXIO;
 
-       while (offset < size) {
-               ret = iomap_apply(inode, offset, size - offset, IOMAP_REPORT,
-                                 ops, &offset, iomap_seek_hole_actor);
-               if (ret < 0)
-                       return ret;
-               if (ret == 0)
-                       break;
-               offset += ret;
-       }
-
-       return offset;
+       iter.len = size - pos;
+       while ((ret = iomap_iter(&iter, ops)) > 0)
+               iter.processed = iomap_seek_hole_iter(&iter, &pos);
+       if (ret < 0)
+               return ret;
+       if (iter.len) /* found hole before EOF */
+               return pos;
+       return size;
 }
 EXPORT_SYMBOL_GPL(iomap_seek_hole);