vfs: remove DCACHE_NEED_LOOKUP

The code that relied on that flag was ripped out of btrfs quite some
time ago, and never added back. Josef indicated that he was going to
take a different approach to the problem in btrfs, and that we
could just eliminate this flag.

Cc: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 3 insertions, 65 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 67ed24ae86bb..16d9e8e191e6 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4262,16 +4262,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
         if (dentry->d_name.len > BTRFS_NAME_LEN)
                 return ERR_PTR(-ENAMETOOLONG);
 
-        if (unlikely(d_need_lookup(dentry))) {
-                memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
-                kfree(dentry->d_fsdata);
-                dentry->d_fsdata = NULL;
-                /* This thing is hashed, drop it for now */
-                d_drop(dentry);
-        } else {
-                ret = btrfs_inode_by_name(dir, dentry, &location);
-        }
-
+        ret = btrfs_inode_by_name(dir, dentry, &location);
         if (ret < 0)
                 return ERR_PTR(ret);
 
@@ -4341,11 +4332,6 @@ static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
         struct dentry *ret;
 
         ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
-        if (unlikely(d_need_lookup(dentry))) {
-                spin_lock(&dentry->d_lock);
-                dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
-                spin_unlock(&dentry->d_lock);
-        }
         return ret;
 }
 
diff --git a/fs/dcache.c b/fs/dcache.c
index 3a463d0c4fe8..1782be3fc3ef 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -455,24 +455,6 @@ void d_drop(struct dentry *dentry)
 EXPORT_SYMBOL(d_drop);
 
 /*
- * d_clear_need_lookup - drop a dentry from cache and clear the need lookup flag
- * @dentry: dentry to drop
- *
- * This is called when we do a lookup on a placeholder dentry that needed to be
- * looked up.  The dentry should have been hashed in order for it to be found by
- * the lookup code, but now needs to be unhashed while we do the actual lookup
- * and clear the DCACHE_NEED_LOOKUP flag.
- */
-void d_clear_need_lookup(struct dentry *dentry)
-{
-        spin_lock(&dentry->d_lock);
-        __d_drop(dentry);
-        dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
-        spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL(d_clear_need_lookup);
-
-/*
  * Finish off a dentry we've decided to kill.
  * dentry->d_lock must be held, returns with it unlocked.
  * If ref is non-zero, then decrement the refcount too.
@@ -565,13 +547,7 @@ repeat:
         if (d_unhashed(dentry))
                 goto kill_it;
 
-        /*
-         * If this dentry needs lookup, don't set the referenced flag so that it
-         * is more likely to be cleaned up by the dcache shrinker in case of
-         * memory pressure.
-         */
-        if (!d_need_lookup(dentry))
-                dentry->d_flags |= DCACHE_REFERENCED;
+        dentry->d_flags |= DCACHE_REFERENCED;
         dentry_lru_add(dentry);
 
         dentry->d_count--;
@@ -1737,13 +1713,6 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
         }
 
         /*
-         * We are going to instantiate this dentry, unhash it and clear the
-         * lookup flag so we can do that.
-         */
-        if (unlikely(d_need_lookup(found)))
-                d_clear_need_lookup(found);
-
-        /*
          * Negative dentry: instantiate it unless the inode is a directory and
          * already has a dentry.
          */
diff --git a/fs/namei.c b/fs/namei.c
index 35195ff9d194..25a41e02984b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1275,9 +1275,7 @@ static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir,
         *need_lookup = false;
         dentry = d_lookup(dir, name);
         if (dentry) {
-                if (d_need_lookup(dentry)) {
-                        *need_lookup = true;
-                } else if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
+                if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
                         error = d_revalidate(dentry, flags);
                         if (unlikely(error <= 0)) {
                                 if (error < 0) {
@@ -1383,8 +1381,6 @@ static int lookup_fast(struct nameidata *nd, struct qstr *name,
                         return -ECHILD;
                 nd->seq = seq;
 
-                if (unlikely(d_need_lookup(dentry)))
-                        goto unlazy;
                 if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
                         status = d_revalidate(dentry, nd->flags);
                         if (unlikely(status <= 0)) {
@@ -1410,11 +1406,6 @@ unlazy:
         if (unlikely(!dentry))
                 goto need_lookup;
 
-        if (unlikely(d_need_lookup(dentry))) {
-                dput(dentry);
-                goto need_lookup;
-        }
-
         if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval)
                 status = d_revalidate(dentry, nd->flags);
         if (unlikely(status <= 0)) {
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 59200795482e..c1754b59ddd3 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -202,7 +202,6 @@ struct dentry_operations {
 #define DCACHE_MOUNTED          0x10000 /* is a mountpoint */
 #define DCACHE_NEED_AUTOMOUNT   0x20000 /* handle automount on this dir */
 #define DCACHE_MANAGE_TRANSIT   0x40000 /* manage transit from this dirent */
-#define DCACHE_NEED_LOOKUP      0x80000 /* dentry requires i_op->lookup */
 #define DCACHE_MANAGED_DENTRY \
         (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
 
@@ -408,13 +407,6 @@ static inline bool d_mountpoint(struct dentry *dentry)
         return dentry->d_flags & DCACHE_MOUNTED;
 }
 
-static inline bool d_need_lookup(struct dentry *dentry)
-{
-        return dentry->d_flags & DCACHE_NEED_LOOKUP;
-}
-
-extern void d_clear_need_lookup(struct dentry *dentry);
-
 extern int sysctl_vfs_cache_pressure;
 
 #endif  /* __LINUX_DCACHE_H */