writeback: fix comment, use helper function
There's a comment in there which claims that the inode is left on s_io
if nfs chickened out of writing some data.
But that's not been true for three years.
9290280ced13c85689adeffa587e9a53bd3a5873 fixed a livelock by moving these
inodes back onto s_dirty. Fix the comment.
In the second leg of the `if', use redirty_tail() rather than open-coding it.
Add weaselly comment indicating lack of confidence in the code and lack of the
fortitude which would be needed to fiddle with it.
Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index eb8dc1f..a3d7a82 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -201,7 +201,6 @@
{
unsigned dirty;
struct address_space *mapping = inode->i_mapping;
- struct super_block *sb = inode->i_sb;
int wait = wbc->sync_mode == WB_SYNC_ALL;
int ret;
@@ -237,7 +236,16 @@
/*
* We didn't write back all the pages. nfs_writepages()
* sometimes bales out without doing anything. Redirty
- * the inode. It is still on sb->s_io.
+ * the inode. It is moved from s_io onto s_dirty.
+ */
+ /*
+ * akpm: if the caller was the kupdate function we put
+ * this inode at the head of s_dirty so it gets first
+ * consideration. Otherwise, move it to the tail, for
+ * the reasons described there. I'm not really sure
+ * how much sense this makes. Presumably I had a good
+ * reasons for doing it this way, and I'd rather not
+ * muck with it at present.
*/
if (wbc->for_kupdate) {
/*
@@ -257,8 +265,7 @@
* all the other files.
*/
inode->i_state |= I_DIRTY_PAGES;
- inode->dirtied_when = jiffies;
- list_move(&inode->i_list, &sb->s_dirty);
+ redirty_tail(inode);
}
} else if (inode->i_state & I_DIRTY) {
/*