From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Result will be massaged to saner shape in the next commits. It is
ugly, no questions - the point of that one is to be a provably
equivalent transformation (and it might be worth splitting a bit
more).
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
(cherry picked from commit ff2fde9929feb2aef45377ce56b8b12df85dda69)
---
fs/dcache.c | 30 +++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 9a0ea05..5cdd171 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -800,6 +800,7 @@ static void shrink_dentry_list(struct list_head *list)
struct dentry *dentry, *parent;
while (!list_empty(list)) {
+ struct inode *inode;
dentry = list_entry(list->prev, struct dentry, d_lru);
spin_lock(&dentry->d_lock);
/*
@@ -827,23 +828,26 @@ static void shrink_dentry_list(struct list_head *list)
continue;
}
- parent = dentry_kill(dentry, 0);
- /*
- * If dentry_kill returns NULL, we have nothing more to do.
- */
- if (!parent)
- continue;
-
- if (unlikely(parent == dentry)) {
- /*
- * trylocks have failed and d_lock has been held the
- * whole time, so it could not have been added to any
- * other lists. Just add it back to the shrink list.
- */
+ inode = dentry->d_inode;
+ if (inode && unlikely(!spin_trylock(&inode->i_lock))) {
d_shrink_add(dentry, list);
spin_unlock(&dentry->d_lock);
continue;
}
+
+ parent = NULL;
+ if (!IS_ROOT(dentry)) {
+ parent = dentry->d_parent;
+ if (unlikely(!spin_trylock(&parent->d_lock))) {
+ if (inode)
+ spin_unlock(&inode->i_lock);
+ d_shrink_add(dentry, list);
+ spin_unlock(&dentry->d_lock);
+ continue;
+ }
+ }
+
+ __dentry_kill(dentry);
/*
* We need to prune ancestors too. This is necessary to prevent
* quadratic behavior of shrink_dcache_parent(), but is also
--
1.8.3.1
--
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