1 files changed, 32 insertions, 45 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index f09b9085f7d8..87bdb5329c3c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1612,6 +1612,10 @@ EXPORT_SYMBOL(d_obtain_alias);
  * If a dentry was found and moved, then it is returned.  Otherwise NULL
  * is returned.  This matches the expected return value of ->lookup.
  *
+ * Cluster filesystems may call this function with a negative, hashed dentry.
+ * In that case, we know that the inode will be a regular file, and also this
+ * will only occur during atomic_open. So we need to check for the dentry
+ * being already hashed only in the final case.
  */
 struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
 {
@@ -1636,8 +1640,11 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
                         security_d_instantiate(dentry, inode);
                         d_rehash(dentry);
                 }
-        } else
-                d_add(dentry, inode);
+        } else {
+                d_instantiate(dentry, inode);
+                if (d_unhashed(dentry))
+                        d_rehash(dentry);
+        }
         return new;
 }
 EXPORT_SYMBOL(d_splice_alias);
@@ -1723,7 +1730,7 @@ EXPORT_SYMBOL(d_add_ci);
  * Do the slow-case of the dentry name compare.
  *
  * Unlike the dentry_cmp() function, we need to atomically
- * load the name, length and inode information, so that the
+ * load the name and length information, so that the
  * filesystem can rely on them, and can use the 'name' and
  * 'len' information without worrying about walking off the
  * end of memory etc.
@@ -1741,22 +1748,18 @@ enum slow_d_compare {
 
 static noinline enum slow_d_compare slow_dentry_cmp(
                 const struct dentry *parent,
-                struct inode *inode,
                 struct dentry *dentry,
                 unsigned int seq,
                 const struct qstr *name)
 {
         int tlen = dentry->d_name.len;
         const char *tname = dentry->d_name.name;
-        struct inode *i = dentry->d_inode;
 
         if (read_seqcount_retry(&dentry->d_seq, seq)) {
                 cpu_relax();
                 return D_COMP_SEQRETRY;
         }
-        if (parent->d_op->d_compare(parent, inode,
-                                dentry, i,
-                                tlen, tname, name))
+        if (parent->d_op->d_compare(parent, dentry, tlen, tname, name))
                 return D_COMP_NOMATCH;
         return D_COMP_OK;
 }
@@ -1766,7 +1769,6 @@ static noinline enum slow_d_compare slow_dentry_cmp(
  * @parent: parent dentry
  * @name: qstr of name we wish to find
  * @seqp: returns d_seq value at the point where the dentry was found
- * @inode: returns dentry->d_inode when the inode was found valid.
  * Returns: dentry, or NULL
  *
  * __d_lookup_rcu is the dcache lookup function for rcu-walk name
@@ -1793,7 +1795,7 @@ static noinline enum slow_d_compare slow_dentry_cmp(
  */
 struct dentry *__d_lookup_rcu(const struct dentry *parent,
                                 const struct qstr *name,
-                                unsigned *seqp, struct inode *inode)
+                                unsigned *seqp)
 {
         u64 hashlen = name->hash_len;
         const unsigned char *str = name->name;
@@ -1827,11 +1829,10 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent,
 seqretry:
                 /*
                  * The dentry sequence count protects us from concurrent
-                 * renames, and thus protects inode, parent and name fields.
+                 * renames, and thus protects parent and name fields.
                  *
                  * The caller must perform a seqcount check in order
-                 * to do anything useful with the returned dentry,
-                 * including using the 'd_inode' pointer.
+                 * to do anything useful with the returned dentry.
                  *
                  * NOTE! We do a "raw" seqcount_begin here. That means that
                  * we don't wait for the sequence count to stabilize if it
@@ -1845,12 +1846,12 @@ seqretry:
                         continue;
                 if (d_unhashed(dentry))
                         continue;
-                *seqp = seq;
 
                 if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
                         if (dentry->d_name.hash != hashlen_hash(hashlen))
                                 continue;
-                        switch (slow_dentry_cmp(parent, inode, dentry, seq, name)) {
+                        *seqp = seq;
+                        switch (slow_dentry_cmp(parent, dentry, seq, name)) {
                         case D_COMP_OK:
                                 return dentry;
                         case D_COMP_NOMATCH:
@@ -1862,6 +1863,7 @@ seqretry:
 
                 if (dentry->d_name.hash_len != hashlen)
                         continue;
+                *seqp = seq;
                 if (!dentry_cmp(dentry, str, hashlen_len(hashlen)))
                         return dentry;
         }
@@ -1959,9 +1961,7 @@ struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
                 if (parent->d_flags & DCACHE_OP_COMPARE) {
                         int tlen = dentry->d_name.len;
                         const char *tname = dentry->d_name.name;
-                        if (parent->d_op->d_compare(parent, parent->d_inode,
-                                                dentry, dentry->d_inode,
-                                                tlen, tname, name))
+                        if (parent->d_op->d_compare(parent, dentry, tlen, tname, name))
                                 goto next;
                 } else {
                         if (dentry->d_name.len != len)
@@ -1998,7 +1998,7 @@ 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) {
-                int err = dir->d_op->d_hash(dir, dir->d_inode, name);
+                int err = dir->d_op->d_hash(dir, name);
                 if (unlikely(err < 0))
                         return ERR_PTR(err);
         }
@@ -2968,34 +2968,21 @@ rename_retry:
         goto again;
 }
 
-/**
- * find_inode_number - check for dentry with name
- * @dir: directory to check
- * @name: Name to find.
- *
- * Check whether a dentry already exists for the given name,
- * and return the inode number if it has an inode. Otherwise
- * 0 is returned.
- *
- * This routine is used to post-process directory listings for
- * filesystems using synthetic inode numbers, and is necessary
- * to keep getcwd() working.
- */
- 
-ino_t find_inode_number(struct dentry *dir, struct qstr *name)
+void d_tmpfile(struct dentry *dentry, struct inode *inode)
 {
-        struct dentry * dentry;
-        ino_t ino = 0;
-
-        dentry = d_hash_and_lookup(dir, name);
-        if (!IS_ERR_OR_NULL(dentry)) {
-                if (dentry->d_inode)
-                        ino = dentry->d_inode->i_ino;
-                dput(dentry);
-        }
-        return ino;
+        inode_dec_link_count(inode);
+        BUG_ON(dentry->d_name.name != dentry->d_iname ||
+                !hlist_unhashed(&dentry->d_alias) ||
+                !d_unlinked(dentry));
+        spin_lock(&dentry->d_parent->d_lock);
+        spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+        dentry->d_name.len = sprintf(dentry->d_iname, "#%llu",
+                                (unsigned long long)inode->i_ino);
+        spin_unlock(&dentry->d_lock);
+        spin_unlock(&dentry->d_parent->d_lock);
+        d_instantiate(dentry, inode);
 }
-EXPORT_SYMBOL(find_inode_number);
+EXPORT_SYMBOL(d_tmpfile);
 
 static __initdata unsigned long dhash_entries;
 static int __init set_dhash_entries(char *str)