1 files changed, 54 insertions, 44 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 5631d6b2a62d..7b48b2ad00e7 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -750,6 +750,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
 	read_unlock_irq(&mapping->tree_lock);
 	return i;
 }
+EXPORT_SYMBOL(find_get_pages_contig);
 
 /**
  * find_get_pages_tag - find and return pages that match @tag
@@ -778,6 +779,7 @@ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
 	read_unlock_irq(&mapping->tree_lock);
 	return ret;
 }
+EXPORT_SYMBOL(find_get_pages_tag);
 
 /**
  * grab_cache_page_nowait - returns locked page at given index in given cache
@@ -1110,6 +1112,45 @@ success:
 	return size;
 }
 
+/*
+ * Performs necessary checks before doing a write
+ * @iov:	io vector request
+ * @nr_segs:	number of segments in the iovec
+ * @count:	number of bytes to write
+ * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE
+ *
+ * Adjust number of segments and amount of bytes to write (nr_segs should be
+ * properly initialized first). Returns appropriate error code that caller
+ * should return or zero in case that write should be allowed.
+ */
+int generic_segment_checks(const struct iovec *iov,
+			unsigned long *nr_segs, size_t *count, int access_flags)
+{
+	unsigned long   seg;
+	size_t cnt = 0;
+	for (seg = 0; seg < *nr_segs; seg++) {
+		const struct iovec *iv = &iov[seg];
+
+		/*
+		 * If any segment has a negative length, or the cumulative
+		 * length ever wraps negative then return -EINVAL.
+		 */
+		cnt += iv->iov_len;
+		if (unlikely((ssize_t)(cnt|iv->iov_len) < 0))
+			return -EINVAL;
+		if (access_ok(access_flags, iv->iov_base, iv->iov_len))
+			continue;
+		if (seg == 0)
+			return -EFAULT;
+		*nr_segs = seg;
+		cnt -= iv->iov_len;	/* This segment is no good */
+		break;
+	}
+	*count = cnt;
+	return 0;
+}
+EXPORT_SYMBOL(generic_segment_checks);
+
 /**
  * generic_file_aio_read - generic filesystem read routine
  * @iocb:	kernel I/O control block
@@ -1131,24 +1172,9 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 	loff_t *ppos = &iocb->ki_pos;
 
 	count = 0;
-	for (seg = 0; seg < nr_segs; seg++) {
-		const struct iovec *iv = &iov[seg];
-
-		/*
-		 * If any segment has a negative length, or the cumulative
-		 * length ever wraps negative then return -EINVAL.
-		 */
-		count += iv->iov_len;
-		if (unlikely((ssize_t)(count|iv->iov_len) < 0))
-			return -EINVAL;
-		if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
-			continue;
-		if (seg == 0)
-			return -EFAULT;
-		nr_segs = seg;
-		count -= iv->iov_len;	/* This segment is no good */
-		break;
-	}
+	retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+	if (retval)
+		return retval;
 
 	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
 	if (filp->f_flags & O_DIRECT) {
@@ -1758,7 +1784,7 @@ struct page *read_cache_page_async(struct address_space *mapping,
 retry:
 	page = __read_cache_page(mapping, index, filler, data);
 	if (IS_ERR(page))
-		goto out;
+		return page;
 	mark_page_accessed(page);
 	if (PageUptodate(page))
 		goto out;
@@ -1776,9 +1802,9 @@ retry:
 	err = filler(data, page);
 	if (err < 0) {
 		page_cache_release(page);
-		page = ERR_PTR(err);
+		return ERR_PTR(err);
 	}
- out:
+out:
 	mark_page_accessed(page);
 	return page;
 }
@@ -2218,30 +2244,14 @@ __generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
 	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	struct inode 	*inode = mapping->host;
-	unsigned long	seg;
 	loff_t		pos;
 	ssize_t		written;
 	ssize_t		err;
 
 	ocount = 0;
-	for (seg = 0; seg < nr_segs; seg++) {
-		const struct iovec *iv = &iov[seg];
-
-		/*
-		 * If any segment has a negative length, or the cumulative
-		 * length ever wraps negative then return -EINVAL.
-		 */
-		ocount += iv->iov_len;
-		if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
-			return -EINVAL;
-		if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
-			continue;
-		if (seg == 0)
-			return -EFAULT;
-		nr_segs = seg;
-		ocount -= iv->iov_len;	/* This segment is no good */
-		break;
-	}
+	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+	if (err)
+		return err;
 
 	count = ocount;
 	pos = *ppos;
@@ -2301,10 +2311,10 @@ __generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
 		 * semantics.
 		 */
 		endbyte = pos + written_buffered - written - 1;
-		err = do_sync_file_range(file, pos, endbyte,
-					 SYNC_FILE_RANGE_WAIT_BEFORE|
-					 SYNC_FILE_RANGE_WRITE|
-					 SYNC_FILE_RANGE_WAIT_AFTER);
+		err = do_sync_mapping_range(file->f_mapping, pos, endbyte,
+					    SYNC_FILE_RANGE_WAIT_BEFORE|
+					    SYNC_FILE_RANGE_WRITE|
+					    SYNC_FILE_RANGE_WAIT_AFTER);
 		if (err == 0) {
 			written = written_buffered;
 			invalidate_mapping_pages(mapping,