+ ufs-ufs_get_locked_patch-race-fix.patch added to -mm tree

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The patch titled

     ufs: ufs_get_locked_page() race fix

has been added to the -mm tree.  Its filename is

     ufs-ufs_get_locked_patch-race-fix.patch

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: ufs: ufs_get_locked_page() race fix
From: Evgeniy Dushistov <dushistov@xxxxxxx>

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 <dushistov@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

 fs/ufs/util.c |   15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff -puN fs/ufs/util.c~ufs-ufs_get_locked_patch-race-fix fs/ufs/util.c
--- a/fs/ufs/util.c~ufs-ufs_get_locked_patch-race-fix
+++ a/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 != mapping ||
+			     page->index != index)) {
+			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;
 }
_

Patches currently in -mm which might be from dushistov@xxxxxxx are

ufs-remove-incorrect-unlock_kernel-from-failure-path-in-ufs_symlink.patch
ufs-ufs_get_locked_patch-race-fix.patch

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