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authorLinus Torvalds <torvalds@linux-foundation.org>2011-04-24 08:51:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-04-24 08:51:15 -0700
commit5dd12af05ca6b7d052c06a9ca4ff755fdfa25ae4 (patch)
tree15189e860b8fb4e20b1517c8ec2d2e145a2c0017
parent8f7544682c488dfc4117b37ed10435bb2d3d8d73 (diff)
parentdea3667bc3c2a0521e8d8855e407a49d9d70028c (diff)
downloadlinux-5dd12af05ca6b7d052c06a9ca4ff755fdfa25ae4.tar.gz
Merge branch 'dcache-cleanup'
* dcache-cleanup: vfs: get rid of insane dentry hashing rules
-rw-r--r--fs/dcache.c42
-rw-r--r--include/linux/dcache.h4
2 files changed, 18 insertions, 28 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 7108c15685d..d600a0af3b2 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -164,8 +164,8 @@ static void d_free(struct dentry *dentry)
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
- /* if dentry was never inserted into hash, immediate free is OK */
- if (hlist_bl_unhashed(&dentry->d_hash))
+ /* if dentry was never visible to RCU, immediate free is OK */
+ if (!(dentry->d_flags & DCACHE_RCUACCESS))
__d_free(&dentry->d_u.d_rcu);
else
call_rcu(&dentry->d_u.d_rcu, __d_free);
@@ -327,28 +327,19 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
*/
void __d_drop(struct dentry *dentry)
{
- if (!(dentry->d_flags & DCACHE_UNHASHED)) {
+ if (!d_unhashed(dentry)) {
struct hlist_bl_head *b;
- if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
+ if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED))
b = &dentry->d_sb->s_anon;
- spin_lock_bucket(b);
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_init(&dentry->d_hash);
- spin_unlock_bucket(b);
- } else {
- struct hlist_bl_head *b;
+ else
b = d_hash(dentry->d_parent, dentry->d_name.hash);
- spin_lock_bucket(b);
- /*
- * We may not actually need to put DCACHE_UNHASHED
- * manipulations under the hash lock, but follow
- * the principle of least surprise.
- */
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_rcu(&dentry->d_hash);
- spin_unlock_bucket(b);
- dentry_rcuwalk_barrier(dentry);
- }
+
+ spin_lock_bucket(b);
+ __hlist_bl_del(&dentry->d_hash);
+ dentry->d_hash.pprev = NULL;
+ spin_unlock_bucket(b);
+
+ dentry_rcuwalk_barrier(dentry);
}
}
EXPORT_SYMBOL(__d_drop);
@@ -1301,7 +1292,7 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
dname[name->len] = 0;
dentry->d_count = 1;
- dentry->d_flags = DCACHE_UNHASHED;
+ dentry->d_flags = 0;
spin_lock_init(&dentry->d_lock);
seqcount_init(&dentry->d_seq);
dentry->d_inode = NULL;
@@ -1603,10 +1594,9 @@ struct dentry *d_obtain_alias(struct inode *inode)
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
list_add(&tmp->d_alias, &inode->i_dentry);
- bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
- tmp->d_flags &= ~DCACHE_UNHASHED;
+ spin_lock_bucket(&tmp->d_sb->s_anon);
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
- __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
+ spin_unlock_bucket(&tmp->d_sb->s_anon);
spin_unlock(&tmp->d_lock);
spin_unlock(&inode->i_lock);
security_d_instantiate(tmp, inode);
@@ -2087,7 +2077,7 @@ static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
{
BUG_ON(!d_unhashed(entry));
spin_lock_bucket(b);
- entry->d_flags &= ~DCACHE_UNHASHED;
+ entry->d_flags |= DCACHE_RCUACCESS;
hlist_bl_add_head_rcu(&entry->d_hash, b);
spin_unlock_bucket(b);
}
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index f2afed4fa94..19d90a55541 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -197,7 +197,7 @@ struct dentry_operations {
* typically using d_splice_alias. */
#define DCACHE_REFERENCED 0x0008 /* Recently used, don't discard. */
-#define DCACHE_UNHASHED 0x0010
+#define DCACHE_RCUACCESS 0x0010 /* Entry has ever been RCU-visible */
#define DCACHE_INOTIFY_PARENT_WATCHED 0x0020
/* Parent inode is watched by inotify */
@@ -384,7 +384,7 @@ extern struct dentry *dget_parent(struct dentry *dentry);
static inline int d_unhashed(struct dentry *dentry)
{
- return (dentry->d_flags & DCACHE_UNHASHED);
+ return hlist_bl_unhashed(&dentry->d_hash);
}
static inline int d_unlinked(struct dentry *dentry)