From 2c567af418e3f9380c2051aada58b4e5a4b5c2ad Mon Sep 17 00:00:00 2001 From: Ira Weiny Date: Thu, 30 Apr 2020 07:41:37 -0700 Subject: fs: Introduce DCACHE_DONTCACHE DCACHE_DONTCACHE indicates a dentry should not be cached on final dput(). Also add a helper function to mark DCACHE_DONTCACHE on all dentries pointing to a specific inode when that inode is being set I_DONTCACHE. This facilitates dropping dentry references to inodes sooner which require eviction to swap S_DAX mode. Cc: Al Viro Signed-off-by: Ira Weiny Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/dcache.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'fs/dcache.c') diff --git a/fs/dcache.c b/fs/dcache.c index b280e07e162b..0d07fb335b78 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -647,6 +647,10 @@ static inline bool retain_dentry(struct dentry *dentry) if (dentry->d_op->d_delete(dentry)) return false; } + + if (unlikely(dentry->d_flags & DCACHE_DONTCACHE)) + return false; + /* retain; LRU fodder */ dentry->d_lockref.count--; if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) @@ -656,6 +660,21 @@ static inline bool retain_dentry(struct dentry *dentry) return true; } +void d_mark_dontcache(struct inode *inode) +{ + struct dentry *de; + + spin_lock(&inode->i_lock); + hlist_for_each_entry(de, &inode->i_dentry, d_u.d_alias) { + spin_lock(&de->d_lock); + de->d_flags |= DCACHE_DONTCACHE; + spin_unlock(&de->d_lock); + } + inode->i_state |= I_DONTCACHE; + spin_unlock(&inode->i_lock); +} +EXPORT_SYMBOL(d_mark_dontcache); + /* * Finish off a dentry we've decided to kill. * dentry->d_lock must be held, returns with it unlocked. -- cgit v1.2.3-59-g8ed1b