From c5774d112de7663c0773bf4e4a4e5523131bcdb1 Mon Sep 17 00:00:00 2001
From: nikita <nikita>
Date: Wed, 12 Oct 2005 20:46:16 +0000
Subject: [PATCH] cleanup llap_from_page():

 - add explicit LLAP_FROM_REMOVEPAGE

 - make llap_from_page() static

 - fix inverted condition in llap_from_page().

b=5047
r=adilger
---
 lustre/llite/llite_internal.h | 6 +++++-
 lustre/llite/rw.c             | 7 ++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/lustre/llite/llite_internal.h b/lustre/llite/llite_internal.h
index c3d963a..dfefb72 100644
--- a/lustre/llite/llite_internal.h
+++ b/lustre/llite/llite_internal.h
@@ -275,12 +275,17 @@ struct ll_async_page {
         __u32 llap_checksum;
 };
 
+/*
+ * enumeration of llap_from_page() call-sites. Used to export statistics in
+ * /proc/fs/lustre/llite/fsN/dump_page_cache.
+ */
 enum {
         LLAP_ORIGIN_UNKNOWN = 0,
         LLAP_ORIGIN_READPAGE,
         LLAP_ORIGIN_READAHEAD,
         LLAP_ORIGIN_COMMIT_WRITE,
         LLAP_ORIGIN_WRITEPAGE,
+        LLAP_ORIGIN_REMOVEPAGE,
         LLAP__ORIGIN_MAX,
 };
 extern char *llap_origins[];
@@ -337,7 +342,6 @@ extern struct cache_definition ll_cache_definition;
 void ll_removepage(struct page *page);
 int ll_readpage(struct file *file, struct page *page);
 struct ll_async_page *llap_from_cookie(void *cookie);
-struct ll_async_page *llap_from_page(struct page *page, unsigned origin);
 struct ll_async_page *llap_cast_private(struct page *page);
 void ll_readahead_init(struct inode *inode, struct ll_readahead_state *ras);
 void ll_ra_accounting(struct page *page, struct address_space *mapping);
diff --git a/lustre/llite/rw.c b/lustre/llite/rw.c
index 1b86074..5f64cbc 100644
--- a/lustre/llite/rw.c
+++ b/lustre/llite/rw.c
@@ -492,7 +492,7 @@ int llap_shrink_cache(struct ll_sb_info *sbi, int shrink_fraction)
         return count;
 }
 
-struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
+static struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
 {
         struct ll_async_page *llap;
         struct obd_export *exp;
@@ -506,8 +506,9 @@ struct ll_async_page *llap_from_page(struct page *page, unsigned origin)
 
         llap = llap_cast_private(page);
         if (llap != NULL) {
-                /* move to end of LRU list */
-                if (origin == 0) {
+                /* move to end of LRU list, except when page is just about to
+                 * die */
+                if (origin != LLAP_ORIGIN_REMOVEPAGE) {
                         spin_lock(&sbi->ll_lock);
                         sbi->ll_pglist_gen++;
                         list_del_init(&llap->llap_pglist_item);
-- 
1.8.3.1