2 files changed, 91 insertions, 99 deletions

diff --git a/fs/read_write.c b/fs/read_write.c
index c0bcc1a20650..e4d295d0d236 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1753,6 +1753,97 @@ static int generic_remap_check_len(struct inode *inode_in,
 }
 
 /*
+ * Read a page's worth of file data into the page cache.  Return the page
+ * locked.
+ */
+static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
+{
+        struct page *page;
+
+        page = read_mapping_page(inode->i_mapping, offset >> PAGE_SHIFT, NULL);
+        if (IS_ERR(page))
+                return page;
+        if (!PageUptodate(page)) {
+                put_page(page);
+                return ERR_PTR(-EIO);
+        }
+        lock_page(page);
+        return page;
+}
+
+/*
+ * Compare extents of two files to see if they are the same.
+ * Caller must have locked both inodes to prevent write races.
+ */
+static int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
+                                         struct inode *dest, loff_t destoff,
+                                         loff_t len, bool *is_same)
+{
+        loff_t src_poff;
+        loff_t dest_poff;
+        void *src_addr;
+        void *dest_addr;
+        struct page *src_page;
+        struct page *dest_page;
+        loff_t cmp_len;
+        bool same;
+        int error;
+
+        error = -EINVAL;
+        same = true;
+        while (len) {
+                src_poff = srcoff & (PAGE_SIZE - 1);
+                dest_poff = destoff & (PAGE_SIZE - 1);
+                cmp_len = min(PAGE_SIZE - src_poff,
+                              PAGE_SIZE - dest_poff);
+                cmp_len = min(cmp_len, len);
+                if (cmp_len <= 0)
+                        goto out_error;
+
+                src_page = vfs_dedupe_get_page(src, srcoff);
+                if (IS_ERR(src_page)) {
+                        error = PTR_ERR(src_page);
+                        goto out_error;
+                }
+                dest_page = vfs_dedupe_get_page(dest, destoff);
+                if (IS_ERR(dest_page)) {
+                        error = PTR_ERR(dest_page);
+                        unlock_page(src_page);
+                        put_page(src_page);
+                        goto out_error;
+                }
+                src_addr = kmap_atomic(src_page);
+                dest_addr = kmap_atomic(dest_page);
+
+                flush_dcache_page(src_page);
+                flush_dcache_page(dest_page);
+
+                if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
+                        same = false;
+
+                kunmap_atomic(dest_addr);
+                kunmap_atomic(src_addr);
+                unlock_page(dest_page);
+                unlock_page(src_page);
+                put_page(dest_page);
+                put_page(src_page);
+
+                if (!same)
+                        break;
+
+                srcoff += cmp_len;
+                destoff += cmp_len;
+                len -= cmp_len;
+        }
+
+        *is_same = same;
+        return 0;
+
+out_error:
+        return error;
+}
+
+/*
  * Check that the two inodes are eligible for cloning, the ranges make
  * sense, and then flush all dirty data.  Caller must ensure that the
  * inodes have been locked against any other modifications.
@@ -1923,102 +2014,6 @@ loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
 }
 EXPORT_SYMBOL(vfs_clone_file_range);
 
-/*
- * Read a page's worth of file data into the page cache.  Return the page
- * locked.
- */
-static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
-{
-        struct address_space *mapping;
-        struct page *page;
-        pgoff_t n;
-
-        n = offset >> PAGE_SHIFT;
-        mapping = inode->i_mapping;
-        page = read_mapping_page(mapping, n, NULL);
-        if (IS_ERR(page))
-                return page;
-        if (!PageUptodate(page)) {
-                put_page(page);
-                return ERR_PTR(-EIO);
-        }
-        lock_page(page);
-        return page;
-}
-
-/*
- * Compare extents of two files to see if they are the same.
- * Caller must have locked both inodes to prevent write races.
- */
-int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
-                                  struct inode *dest, loff_t destoff,
-                                  loff_t len, bool *is_same)
-{
-        loff_t src_poff;
-        loff_t dest_poff;
-        void *src_addr;
-        void *dest_addr;
-        struct page *src_page;
-        struct page *dest_page;
-        loff_t cmp_len;
-        bool same;
-        int error;
-
-        error = -EINVAL;
-        same = true;
-        while (len) {
-                src_poff = srcoff & (PAGE_SIZE - 1);
-                dest_poff = destoff & (PAGE_SIZE - 1);
-                cmp_len = min(PAGE_SIZE - src_poff,
-                              PAGE_SIZE - dest_poff);
-                cmp_len = min(cmp_len, len);
-                if (cmp_len <= 0)
-                        goto out_error;
-
-                src_page = vfs_dedupe_get_page(src, srcoff);
-                if (IS_ERR(src_page)) {
-                        error = PTR_ERR(src_page);
-                        goto out_error;
-                }
-                dest_page = vfs_dedupe_get_page(dest, destoff);
-                if (IS_ERR(dest_page)) {
-                        error = PTR_ERR(dest_page);
-                        unlock_page(src_page);
-                        put_page(src_page);
-                        goto out_error;
-                }
-                src_addr = kmap_atomic(src_page);
-                dest_addr = kmap_atomic(dest_page);
-
-                flush_dcache_page(src_page);
-                flush_dcache_page(dest_page);
-
-                if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
-                        same = false;
-
-                kunmap_atomic(dest_addr);
-                kunmap_atomic(src_addr);
-                unlock_page(dest_page);
-                unlock_page(src_page);
-                put_page(dest_page);
-                put_page(src_page);
-
-                if (!same)
-                        break;
-
-                srcoff += cmp_len;
-                destoff += cmp_len;
-                len -= cmp_len;
-        }
-
-        *is_same = same;
-        return 0;
-
-out_error:
-        return error;
-}
-EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
-
 loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
                                  struct file *dst_file, loff_t dst_pos,
                                  loff_t len, unsigned int remap_flags)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 34c22d695011..346036a84f18 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1853,9 +1853,6 @@ extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
 extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
                                    struct file *file_out, loff_t pos_out,
                                    loff_t len, unsigned int remap_flags);
-extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
-                                         struct inode *dest, loff_t destoff,
-                                         loff_t len, bool *is_same);
 extern int vfs_dedupe_file_range(struct file *file,
                                  struct file_dedupe_range *same);
 extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,