From 43c1c9cd244098012441b90c32304f11f1258d43 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 7 Jun 2011 14:09:30 +0100 Subject: [PATCH] VFS: Reorganise shrink_dcache_for_umount_subtree() after demise of dcache_lock Reorganise shrink_dcache_for_umount_subtree() in light of the demise of dcache_lock. Without that dcache_lock, there is no need for the batching of removal of dentries from the system under it (we wanted to make intensive use of the locked data whilst we held it, but didn't want to hold it for long at a time). This works, provided the preceding patch is correct in its removal of locking on dentry->d_lock on the basis that no one should be locking these dentries any more as the whole superblock is defunct. With this patch, the calls to dentry_lru_del() and __d_shrink() are placed at the point where each dentry is detached handled. It is possible that, as an alternative, the batching should still be done - but only for dentry_lru_del() of all a dentry's children in one go. In such a case, the batching would be done under dcache_lru_lock. Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/dcache.c | 22 +++++----------------- 1 file changed, 5 insertions(+), 17 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 9df8b861e18e..2347cdb15abb 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -842,33 +842,21 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) BUG_ON(!IS_ROOT(dentry)); - /* detach this root from the system */ - dentry_lru_del(dentry); - __d_shrink(dentry); - for (;;) { /* descend to the first leaf in the current subtree */ - while (!list_empty(&dentry->d_subdirs)) { - struct dentry *loop; - - /* this is a branch with children - detach all of them - * from the system in one go */ - list_for_each_entry(loop, &dentry->d_subdirs, - d_u.d_child) { - dentry_lru_del(loop); - __d_shrink(loop); - } - - /* move to the first child */ + while (!list_empty(&dentry->d_subdirs)) dentry = list_entry(dentry->d_subdirs.next, struct dentry, d_u.d_child); - } /* consume the dentries from this leaf up through its parents * until we find one with children or run out altogether */ do { struct inode *inode; + /* detach from the system */ + dentry_lru_del(dentry); + __d_shrink(dentry); + if (dentry->d_count != 0) { printk(KERN_ERR "BUG: Dentry %p{i=%lx,n=%s}"