UPSTREAM: PM / devfreq: rk3399_dmc: Remove explictly regulator_put call in .remove

[firefly-linux-kernel-4.4.55.git] / fs / dcache.c

diff --git a/fs/dcache.c b/fs/dcache.c
index 5c33aeb0f68febdd03e6f478c7949fd847e9fdcd..7b8feb6d60c8285234d4dd7cbd82b7604addf484 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -269,9 +269,6 @@ static inline int dname_external(const struct dentry *dentry)
        return dentry->d_name.name != dentry->d_iname;
 }
 
-/*
- * Make sure other CPUs see the inode attached before the type is set.
- */
 static inline void __d_set_inode_and_type(struct dentry *dentry,
                                          struct inode *inode,
                                          unsigned type_flags)
@@ -279,28 +276,18 @@ static inline void __d_set_inode_and_type(struct dentry *dentry,
        unsigned flags;
 
        dentry->d_inode = inode;
-       smp_wmb();
        flags = READ_ONCE(dentry->d_flags);
        flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
        flags |= type_flags;
        WRITE_ONCE(dentry->d_flags, flags);
 }
 
-/*
- * Ideally, we want to make sure that other CPUs see the flags cleared before
- * the inode is detached, but this is really a violation of RCU principles
- * since the ordering suggests we should always set inode before flags.
- *
- * We should instead replace or discard the entire dentry - but that sucks
- * performancewise on mass deletion/rename.
- */
 static inline void __d_clear_type_and_inode(struct dentry *dentry)
 {
        unsigned flags = READ_ONCE(dentry->d_flags);
 
        flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
        WRITE_ONCE(dentry->d_flags, flags);
-       smp_wmb();
        dentry->d_inode = NULL;
 }
 
@@ -370,9 +357,11 @@ static void dentry_unlink_inode(struct dentry * dentry)
        __releases(dentry->d_inode->i_lock)
 {
        struct inode *inode = dentry->d_inode;
+
+       raw_write_seqcount_begin(&dentry->d_seq);
        __d_clear_type_and_inode(dentry);
        hlist_del_init(&dentry->d_u.d_alias);
-       dentry_rcuwalk_invalidate(dentry);
+       raw_write_seqcount_end(&dentry->d_seq);
        spin_unlock(&dentry->d_lock);
        spin_unlock(&inode->i_lock);
        if (!inode->i_nlink)
@@ -589,7 +578,6 @@ static struct dentry *dentry_kill(struct dentry *dentry)
 
 failed:
        spin_unlock(&dentry->d_lock);
-       cpu_relax();
        return dentry; /* try again with same dentry */
 }
 
@@ -763,6 +751,8 @@ void dput(struct dentry *dentry)
                return;
 
 repeat:
+       might_sleep();
+
        rcu_read_lock();
        if (likely(fast_dput(dentry))) {
                rcu_read_unlock();
@@ -794,8 +784,10 @@ repeat:
 
 kill_it:
        dentry = dentry_kill(dentry);
-       if (dentry)
+       if (dentry) {
+               cond_resched();
                goto repeat;
+       }
 }
 EXPORT_SYMBOL(dput);
 
@@ -1330,8 +1322,11 @@ int d_set_mounted(struct dentry *dentry)
        }
        spin_lock(&dentry->d_lock);
        if (!d_unlinked(dentry)) {
-               dentry->d_flags |= DCACHE_MOUNTED;
-               ret = 0;
+               ret = -EBUSY;
+               if (!d_mountpoint(dentry)) {
+                       dentry->d_flags |= DCACHE_MOUNTED;
+                       ret = 0;
+               }
        }
        spin_unlock(&dentry->d_lock);
 out:
@@ -1629,7 +1624,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
        struct dentry *dentry = __d_alloc(parent->d_sb, name);
        if (!dentry)
                return NULL;
-
+       dentry->d_flags |= DCACHE_RCUACCESS;
        spin_lock(&parent->d_lock);
        /*
         * don't need child lock because it is not subject
@@ -1677,7 +1672,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
                                DCACHE_OP_REVALIDATE    |
                                DCACHE_OP_WEAK_REVALIDATE       |
                                DCACHE_OP_DELETE        |
-                               DCACHE_OP_SELECT_INODE));
+                               DCACHE_OP_SELECT_INODE  |
+                               DCACHE_OP_REAL));
        dentry->d_op = op;
        if (!op)
                return;
@@ -1695,6 +1691,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
                dentry->d_flags |= DCACHE_OP_PRUNE;
        if (op->d_select_inode)
                dentry->d_flags |= DCACHE_OP_SELECT_INODE;
+       if (op->d_real)
+               dentry->d_flags |= DCACHE_OP_REAL;
 
 }
 EXPORT_SYMBOL(d_set_d_op);
@@ -1757,8 +1755,9 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
        spin_lock(&dentry->d_lock);
        if (inode)
                hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
+       raw_write_seqcount_begin(&dentry->d_seq);
        __d_set_inode_and_type(dentry, inode, add_flags);
-       dentry_rcuwalk_invalidate(dentry);
+       raw_write_seqcount_end(&dentry->d_seq);
        spin_unlock(&dentry->d_lock);
        fsnotify_d_instantiate(dentry, inode);
 }
@@ -2420,7 +2419,6 @@ static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
 {
        BUG_ON(!d_unhashed(entry));
        hlist_bl_lock(b);
-       entry->d_flags |= DCACHE_RCUACCESS;
        hlist_bl_add_head_rcu(&entry->d_hash, b);
        hlist_bl_unlock(b);
 }
@@ -2639,6 +2637,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
        /* ... and switch them in the tree */
        if (IS_ROOT(dentry)) {
                /* splicing a tree */
+               dentry->d_flags |= DCACHE_RCUACCESS;
                dentry->d_parent = target->d_parent;
                target->d_parent = target;
                list_del_init(&target->d_child);
@@ -3027,6 +3026,7 @@ char *d_absolute_path(const struct path *path,
                return ERR_PTR(error);
        return res;
 }
+EXPORT_SYMBOL(d_absolute_path);
 
 /*
  * same as __d_path but appends "(deleted)" for unlinked files.