From: Ira Weiny <ira.weiny@xxxxxxxxx>
DCACHE_DONTCACHE indicates a dentry should not be cached on final
dput().
Also add a helper function which will flag I_DONTCACHE as well ad
DCACHE_DONTCACHE on all dentries point to a specified inode.
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
Changes from V7:
new patch
---
fs/dcache.c | 4 ++++
fs/inode.c | 15 +++++++++++++++
include/linux/dcache.h | 2 ++
include/linux/fs.h | 1 +
4 files changed, 22 insertions(+)
diff --git a/fs/dcache.c b/fs/dcache.c
index b280e07e162b..0030fabab2c4 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)))
diff --git a/fs/inode.c b/fs/inode.c
index 93d9252a00ab..b8b1917a324e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1526,6 +1526,21 @@ int generic_delete_inode(struct inode *inode)
}
EXPORT_SYMBOL(generic_delete_inode);
+void flag_inode_dontcache(struct inode *inode)
+{
+ struct dentry *dent;
+
+ rcu_read_lock();
+ hlist_for_each_entry(dent, &inode->i_dentry, d_u.d_alias) {
+ spin_lock(&dent->d_lock);
+ dent->d_flags |= DCACHE_DONTCACHE;
+ spin_unlock(&dent->d_lock);
+ }
+ rcu_read_unlock();
+ inode->i_state |= I_DONTCACHE;
+}
+EXPORT_SYMBOL(flag_inode_dontcache);
+
/*
* Called when we're dropping the last reference
* to an inode.
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index c1488cc84fd9..56b1482d9223 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -177,6 +177,8 @@ struct dentry_operations {
#define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */
+#define DCACHE_DONTCACHE 0x00000080 /* don't cache on final dput() */
+
#define DCACHE_CANT_MOUNT 0x00000100
#define DCACHE_GENOCIDE 0x00000200
#define DCACHE_SHRINK_LIST 0x00000400
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e2db71d150c3..f2916c99616a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3048,6 +3048,7 @@ static inline int generic_drop_inode(struct inode *inode)
return !inode->i_nlink || inode_unhashed(inode) ||
(inode->i_state & I_DONTCACHE);
}
+extern void flag_inode_dontcache(struct inode *inode);
extern struct inode *ilookup5_nowait(struct super_block *sb,
unsigned long hashval, int (*test)(struct inode *, void *),
--
2.25.1
