d_hash_and_lookup(): export, switch open-coded instances

* calling conventions change - ERR_PTR() is returned on ->d_hash() errors;
NULL is just for dcache miss now.
* exported, open-coded instances in ncpfs and cifs converted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 18 insertions, 24 deletions

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 7255b0c7aa7e..df40cc5fd13a 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -82,12 +82,10 @@ cifs_prime_dcache(struct dentry *parent, struct qstr *name,
 
         cFYI(1, "%s: for %s", __func__, name->name);
 
-        if (parent->d_op && parent->d_op->d_hash)
-                parent->d_op->d_hash(parent, parent->d_inode, name);
-        else
-                name->hash = full_name_hash(name->name, name->len);
+        dentry = d_hash_and_lookup(parent, name);
+        if (unlikely(IS_ERR(dentry)))
+                return;
 
-        dentry = d_lookup(parent, name);
         if (dentry) {
                 int err;
 
diff --git a/fs/dcache.c b/fs/dcache.c
index ada6123414ae..ebab049826c0 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1672,7 +1672,6 @@ EXPORT_SYMBOL(d_splice_alias);
 struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
                         struct qstr *name)
 {
-        int error;
         struct dentry *found;
         struct dentry *new;
 
@@ -1681,10 +1680,12 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
          * if not go ahead and create it now.
          */
         found = d_hash_and_lookup(dentry->d_parent, name);
+        if (unlikely(IS_ERR(found)))
+                goto err_out;
         if (!found) {
                 new = d_alloc(dentry->d_parent, name);
                 if (!new) {
-                        error = -ENOMEM;
+                        found = ERR_PTR(-ENOMEM);
                         goto err_out;
                 }
 
@@ -1725,7 +1726,7 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
 
 err_out:
         iput(inode);
-        return ERR_PTR(error);
+        return found;
 }
 EXPORT_SYMBOL(d_add_ci);
 
@@ -1997,12 +1998,10 @@ next:
  * @dir: Directory to search in
  * @name: qstr of name we wish to find
  *
- * On hash failure or on lookup failure NULL is returned.
+ * On lookup failure NULL is returned; on bad name - ERR_PTR(-error)
  */
 struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
 {
-        struct dentry *dentry = NULL;
-
         /*
          * Check for a fs-specific hash function. Note that we must
          * calculate the standard hash first, as the d_op->d_hash()
@@ -2010,13 +2009,13 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
          */
         name->hash = full_name_hash(name->name, name->len);
         if (dir->d_flags & DCACHE_OP_HASH) {
-                if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
-                        goto out;
+                int err = dir->d_op->d_hash(dir, dir->d_inode, name);
+                if (unlikely(err < 0))
+                        return ERR_PTR(err);
         }
-        dentry = d_lookup(dir, name);
-out:
-        return dentry;
+        return d_lookup(dir, name);
 }
+EXPORT_SYMBOL(d_hash_and_lookup);
 
 /**
  * d_validate - verify dentry provided from insecure source (deprecated)
@@ -2995,7 +2994,7 @@ ino_t find_inode_number(struct dentry *dir, struct qstr *name)
         ino_t ino = 0;
 
         dentry = d_hash_and_lookup(dir, name);
-        if (dentry) {
+        if (!IS_ERR_OR_NULL(dentry)) {
                 if (dentry->d_inode)
                         ino = dentry->d_inode->i_ino;
                 dput(dentry);
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 4117e7b377bb..816326093656 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -593,14 +593,10 @@ ncp_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
                 return 1; /* I'm not sure */
 
         qname.name = __name;
-        qname.hash = full_name_hash(qname.name, qname.len);
-
-        if (dentry->d_op && dentry->d_op->d_hash)
-                if (dentry->d_op->d_hash(dentry, dentry->d_inode, &qname) != 0)
-                        goto end_advance;
-
-        newdent = d_lookup(dentry, &qname);
 
+        newdent = d_hash_and_lookup(dentry, &qname);
+        if (unlikely(IS_ERR(newdent)))
+                goto end_advance;
         if (!newdent) {
                 newdent = d_alloc(dentry, &qname);
                 if (!newdent)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 760268d6cba6..9d9625559727 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2618,6 +2618,7 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
 
         name.name = buf;
         name.len = snprintf(buf, sizeof(buf), "%d", pid);
+        /* no ->d_hash() rejects on procfs */
         dentry = d_hash_and_lookup(mnt->mnt_root, &name);
         if (dentry) {
                 shrink_dcache_parent(dentry);