diff options
| -rw-r--r-- | fs/dcache.c | 13 | ||||
| -rw-r--r-- | fs/namei.c | 4 | ||||
| -rw-r--r-- | include/linux/dcache.h | 18 |
3 files changed, 35 insertions, 0 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 20394fb6f967..0f1d93866e69 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -761,6 +761,8 @@ repeat: /* Slow case: now with the dentry lock held */ rcu_read_unlock(); + WARN_ON(d_in_lookup(dentry)); + /* Unreachable? Get rid of it */ if (unlikely(d_unhashed(dentry))) goto kill_it; @@ -1746,6 +1748,7 @@ type_determined: static void __d_instantiate(struct dentry *dentry, struct inode *inode) { unsigned add_flags = d_flags_for_inode(inode); + WARN_ON(d_in_lookup(dentry)); spin_lock(&dentry->d_lock); hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); @@ -2361,12 +2364,20 @@ void d_rehash(struct dentry * entry) } EXPORT_SYMBOL(d_rehash); +void __d_lookup_done(struct dentry *dentry) +{ + dentry->d_flags &= ~DCACHE_PAR_LOOKUP; + /* more stuff will land here */ +} +EXPORT_SYMBOL(__d_lookup_done); /* inode->i_lock held if inode is non-NULL */ static inline void __d_add(struct dentry *dentry, struct inode *inode) { spin_lock(&dentry->d_lock); + if (unlikely(d_in_lookup(dentry))) + __d_lookup_done(dentry); if (inode) { unsigned add_flags = d_flags_for_inode(inode); hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); @@ -2612,6 +2623,8 @@ static void __d_move(struct dentry *dentry, struct dentry *target, BUG_ON(d_ancestor(target, dentry)); dentry_lock_for_move(dentry, target); + if (unlikely(d_in_lookup(target))) + __d_lookup_done(target); write_seqcount_begin(&dentry->d_seq); write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED); diff --git a/fs/namei.c b/fs/namei.c index c275635c4b9e..26e5f84e0c36 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1634,7 +1634,11 @@ static struct dentry *lookup_slow(const struct qstr *name, inode_unlock(inode); return ERR_PTR(-ENOMEM); } + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_PAR_LOOKUP; + spin_unlock(&dentry->d_lock); old = inode->i_op->lookup(inode, dentry, flags); + d_lookup_done(dentry); if (unlikely(old)) { dput(dentry); dentry = old; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 4bb4de8d95ea..9a7aa890b642 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -232,6 +232,8 @@ struct dentry_operations { #define DCACHE_ENCRYPTED_WITH_KEY 0x04000000 /* dir is encrypted with a valid key */ #define DCACHE_OP_REAL 0x08000000 +#define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */ + extern seqlock_t rename_lock; /* @@ -367,6 +369,22 @@ static inline void dont_mount(struct dentry *dentry) spin_unlock(&dentry->d_lock); } +extern void __d_lookup_done(struct dentry *); + +static inline int d_in_lookup(struct dentry *dentry) +{ + return dentry->d_flags & DCACHE_PAR_LOOKUP; +} + +static inline void d_lookup_done(struct dentry *dentry) +{ + if (unlikely(d_in_lookup(dentry))) { + spin_lock(&dentry->d_lock); + __d_lookup_done(dentry); + spin_unlock(&dentry->d_lock); + } +} + extern void dput(struct dentry *); static inline bool d_managed(const struct dentry *dentry) |