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authorZach Brown <zach.brown@oracle.com>2005-12-16 01:28:17 +0300
committerJoel Becker <joel.becker@oracle.com>2006-01-03 22:45:42 +0300
commit994fc28c7b1e697ac56befe4aecabf23f0689f46 (patch)
treeda36d162e9bd077e9b5be385b28e2db90475c263 /mm/readahead.c
parent7063fbf2261194f72ee75afca67b3b38b554b5fa (diff)
downloadlinux-994fc28c7b1e697ac56befe4aecabf23f0689f46.tar.xz
[PATCH] add AOP_TRUNCATED_PAGE, prepend AOP_ to WRITEPAGE_ACTIVATE
readpage(), prepare_write(), and commit_write() callers are updated to understand the special return code AOP_TRUNCATED_PAGE in the style of writepage() and WRITEPAGE_ACTIVATE. AOP_TRUNCATED_PAGE tells the caller that the callee has unlocked the page and that the operation should be tried again with a new page. OCFS2 uses this to detect and work around a lock inversion in its aop methods. There should be no change in behaviour for methods that don't return AOP_TRUNCATED_PAGE. WRITEPAGE_ACTIVATE is also prepended with AOP_ for consistency and they are made enums so that kerneldoc can be used to document their semantics. Signed-off-by: Zach Brown <zach.brown@oracle.com>
Diffstat (limited to 'mm/readahead.c')
-rw-r--r--mm/readahead.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/mm/readahead.c b/mm/readahead.c
index 72e7adbb87c7..8d6eeaaa6296 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -158,7 +158,7 @@ static int read_pages(struct address_space *mapping, struct file *filp,
{
unsigned page_idx;
struct pagevec lru_pvec;
- int ret = 0;
+ int ret;
if (mapping->a_ops->readpages) {
ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
@@ -171,14 +171,17 @@ static int read_pages(struct address_space *mapping, struct file *filp,
list_del(&page->lru);
if (!add_to_page_cache(page, mapping,
page->index, GFP_KERNEL)) {
- mapping->a_ops->readpage(filp, page);
- if (!pagevec_add(&lru_pvec, page))
- __pagevec_lru_add(&lru_pvec);
- } else {
- page_cache_release(page);
+ ret = mapping->a_ops->readpage(filp, page);
+ if (ret != AOP_TRUNCATED_PAGE) {
+ if (!pagevec_add(&lru_pvec, page))
+ __pagevec_lru_add(&lru_pvec);
+ continue;
+ } /* else fall through to release */
}
+ page_cache_release(page);
}
pagevec_lru_add(&lru_pvec);
+ ret = 0;
out:
return ret;
}