From 1fb32b7bd8203d0175649a75ede3ee7634d6a941 Mon Sep 17 00:00:00 2001 From: Evgeniy Dushistov Date: Sat, 5 Aug 2006 12:13:55 -0700 Subject: [PATCH] [PATCH] ufs: ufs_get_locked_page() race fix As discussed earlier: http://lkml.org/lkml/2006/6/28/136 this patch fixes such issue: `ufs_get_locked_page' takes page from cache after that `vmtruncate' takes page and deletes it from cache `ufs_get_locked_page' locks page, and reports about EIO error. Also because of find_lock_page always return valid page or NULL, we have no need to check it if page not NULL. Signed-off-by: Evgeniy Dushistov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ufs/util.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/fs/ufs/util.c b/fs/ufs/util.c index 337cf2c46d10..005d6815adf5 100644 --- a/fs/ufs/util.c +++ b/fs/ufs/util.c @@ -257,6 +257,7 @@ try_again: page = read_cache_page(mapping, index, (filler_t*)mapping->a_ops->readpage, NULL); + if (IS_ERR(page)) { printk(KERN_ERR "ufs_change_blocknr: " "read_cache_page error: ino %lu, index: %lu\n", @@ -266,6 +267,13 @@ try_again: lock_page(page); + if (unlikely(page->mapping == NULL)) { + /* Truncate got there first */ + unlock_page(page); + page_cache_release(page); + goto try_again; + } + if (!PageUptodate(page) || PageError(page)) { unlock_page(page); page_cache_release(page); @@ -275,15 +283,8 @@ try_again: mapping->host->i_ino, index); page = ERR_PTR(-EIO); - goto out; } } - - if (unlikely(!page->mapping || !page_has_buffers(page))) { - unlock_page(page); - page_cache_release(page); - goto try_again;/*we really need these buffers*/ - } out: return page; } -- 2.20.1