[PATCH] filemap_fdatawrite_range() api: clarify -end parameter
I had trouble understanding working out whether filemap_fdatawrite_range()'s
`end' parameter describes the last-byte-to-be-written or the last-plus-one.
Clarify that in comments.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/filemap.c b/mm/filemap.c
index d4ff48e..c1b1708 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -175,7 +175,7 @@
* dirty pages that lie within the byte offsets <start, end>
* @mapping: address space structure to write
* @start: offset in bytes where the range starts
- * @end: offset in bytes where the range ends
+ * @end: offset in bytes where the range ends (inclusive)
* @sync_mode: enable synchronous operation
*
* If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
@@ -368,6 +368,12 @@
}
EXPORT_SYMBOL(filemap_write_and_wait);
+/*
+ * Write out and wait upon file offsets lstart->lend, inclusive.
+ *
+ * Note that `lend' is inclusive (describes the last byte to be written) so
+ * that this function can be used to write to the very end-of-file (end = -1).
+ */
int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend)
{
