From b39bab4d48937298f80a898b41f9124c506efda5 Mon Sep 17 00:00:00 2001
From: fanyong <fanyong>
Date: Fri, 20 Mar 2009 08:52:32 +0000
Subject: [PATCH] Branch b1_8 b=17336 i=robert.read i=jinshan.xiong

Do not trigger readpage when objective page index exceeds the end-of-file page index.
---
 lustre/liblustre/rw.c |  9 +++++++++
 lustre/llite/file.c   | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/lustre/liblustre/rw.c b/lustre/liblustre/rw.c
index 96a4b95..12e52e1 100644
--- a/lustre/liblustre/rw.c
+++ b/lustre/liblustre/rw.c
@@ -704,6 +704,15 @@ ssize_t llu_file_prwv(const struct iovec *iovec, int iovlen,
                          */
                         if ((err = llu_glimpse_size(inode))) {
                                 GOTO(err_unlock, err);
+                        } else {
+                                /* If objective page index exceed end-of-file
+                                 * page index, return directly. --bug 17336 */
+                                size_t size = st->st_size;
+                                unsigned long cur_index = pos >> CFS_PAGE_SHIFT;
+
+                                if ((size == 0 && cur_index != 0) ||
+                                    (((size - 1) >> CFS_PAGE_SHIFT) < cur_index))
+                                        GOTO(err_unlock, err);
                         }
                 } else {
                         st->st_size = kms;
diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index a99040a..d62d915 100644
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -1549,6 +1549,24 @@ repeat:
                                 up_read(&lli->lli_truncate_rwsem);
                         }
                         goto out;
+                } else {
+                        /* If objective page index exceed the end-of-file page
+                         * index, return directly. Do not expect kernel will
+                         * check such case correctly. linux-2.6.18-128.1.1 miss
+                         * to do that. --bug 17336 */
+                        size_t size = i_size_read(inode);
+                        unsigned long cur_index = *ppos >> CFS_PAGE_SHIFT;
+
+                        if ((size == 0 && cur_index != 0) ||
+                            (((size - 1) >> CFS_PAGE_SHIFT) < cur_index)) {
+                                if (lock_style != LL_LOCK_STYLE_NOLOCK) {
+                                        ll_file_put_lock(inode, end, lock_style,
+                                                         cookie, &tree,
+                                                         OBD_BRW_READ);
+                                        up_read(&lli->lli_truncate_rwsem);
+                                }
+                                goto out;
+                        }
                 }
         } else {
                 /* region is within kms and, hence, within real file size (A).
-- 
1.8.3.1