fs: make sure to invalidate pages if we fall back on buffered reads

Commit Message

Josef Bacik June 8, 2010, 2:24 p.m. UTC

None

Patch

diff --git a/mm/filemap.c b/mm/filemap.c
index 829ac9c..ca5aba9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1266,6 +1266,7 @@  generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 	unsigned long seg = 0;
 	size_t count;
 	loff_t *ppos = &iocb->ki_pos;
+	bool invalidate = false;
 
 	count = 0;
 	retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
@@ -1291,7 +1292,8 @@  generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 							iov, pos, nr_segs);
 			}
 			if (retval > 0) {
-				*ppos = pos + retval;
+				pos += retval;
+				*ppos = pos;
 				count -= retval;
 			}
 
@@ -1307,6 +1309,7 @@  generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 				file_accessed(filp);
 				goto out;
 			}
+			invalidate = true;
 		}
 	}
 
@@ -1343,6 +1346,10 @@  generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 		if (desc.count > 0)
 			break;
 	}
+	if (invalidate && retval > 0)
+		invalidate_mapping_pages(filp->f_mapping,
+					 pos >> PAGE_CACHE_SHIFT,
+					 (*ppos - 1) >> PAGE_CACHE_SHIFT);
 out:
 	return retval;
 }