Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kern…

…el/git/viro/vfs

Pull more vfs updates from Al Viro:
 "Assorted cleanups and fixes.

  In the "trivial API change" department - ->d_compare() losing 'parent'
  argument"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  cachefiles: Fix race between inactivating and culling a cache object
  9p: use clone_fid()
  9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
  vfs: make dentry_needs_remove_privs() internal
  vfs: remove file_needs_remove_privs()
  vfs: fix deadlock in file_remove_privs() on overlayfs
  get rid of 'parent' argument of ->d_compare()
  cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
  affs ->d_compare(): don't bother with ->d_inode
  fold _d_rehash() and __d_rehash() together
  fold dentry_rcuwalk_invalidate() into its only remaining caller

Documentation/filesystems/Locking

@@ -12,7 +12,7 @@ prototypes:
 	int (*d_revalidate)(struct dentry *, unsigned int);
 	int (*d_weak_revalidate)(struct dentry *, unsigned int);
 	int (*d_hash)(const struct dentry *, struct qstr *);
-	int (*d_compare)(const struct dentry *, const struct dentry *,
+	int (*d_compare)(const struct dentry *,
 			unsigned int, const char *, const struct qstr *);
 	int (*d_delete)(struct dentry *);
 	int (*d_init)(struct dentry *);

Documentation/filesystems/porting

@@ -585,3 +585,10 @@ in your dentry operations instead.
 	in the instances.  Rationale: !@#!@# security_d_instantiate() needs to be
 	called before we attach dentry to inode and !@#!@##!@$!$#!@#$!@$!@$ smack
 	->d_instantiate() uses not just ->getxattr() but ->setxattr() as well.
+--
+[mandatory]
+	->d_compare() doesn't get parent as a separate argument anymore.  If you
+	used it for finding the struct super_block involved, dentry->d_sb will
+	work just as well; if it's something more complicated, use dentry->d_parent.
+	Just be careful not to assume that fetching it more than once will yield
+	the same value - in RCU mode it could change under you.

Documentation/filesystems/vfs.txt

@@ -931,7 +931,7 @@ struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, unsigned int);
 	int (*d_weak_revalidate)(struct dentry *, unsigned int);
 	int (*d_hash)(const struct dentry *, struct qstr *);
-	int (*d_compare)(const struct dentry *, const struct dentry *,
+	int (*d_compare)(const struct dentry *,
 			unsigned int, const char *, const struct qstr *);
 	int (*d_delete)(const struct dentry *);
 	int (*d_init)(struct dentry *);

drivers/staging/lustre/lustre/llite/dcache.c

@@ -78,7 +78,7 @@ static void ll_release(struct dentry *de)
  * INVALID) so d_lookup() matches it, but we have no lock on it (so
  * lock_match() fails) and we spin around real_lookup().
  */
-static int ll_dcompare(const struct dentry *parent, const struct dentry *dentry,
+static int ll_dcompare(const struct dentry *dentry,
 		       unsigned int len, const char *str,
 		       const struct qstr *name)
 {

fs/9p/fid.c

@@ -257,36 +257,12 @@ struct p9_fid *v9fs_fid_lookup(struct dentry *dentry)
 	return v9fs_fid_lookup_with_uid(dentry, uid, any);
 }
 
-struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
-{
-	struct p9_fid *fid, *ret;
-
-	fid = v9fs_fid_lookup(dentry);
-	if (IS_ERR(fid))
-		return fid;
-
-	ret = p9_client_walk(fid, 0, NULL, 1);
-	return ret;
-}
-
-static struct p9_fid *v9fs_fid_clone_with_uid(struct dentry *dentry, kuid_t uid)
-{
-	struct p9_fid *fid, *ret;
-
-	fid = v9fs_fid_lookup_with_uid(dentry, uid, 0);
-	if (IS_ERR(fid))
-		return fid;
-
-	ret = p9_client_walk(fid, 0, NULL, 1);
-	return ret;
-}
-
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry)
 {
 	int err;
 	struct p9_fid *fid;
 
-	fid = v9fs_fid_clone_with_uid(dentry, GLOBAL_ROOT_UID);
+	fid = clone_fid(v9fs_fid_lookup_with_uid(dentry, GLOBAL_ROOT_UID, 0));
 	if (IS_ERR(fid))
 		goto error_out;
 	/*

fs/9p/fid.h

@@ -28,7 +28,14 @@ static inline struct p9_fid *v9fs_parent_fid(struct dentry *dentry)
 {
 	return v9fs_fid_lookup(dentry->d_parent);
 }
-struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
 void v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
+static inline struct p9_fid *clone_fid(struct p9_fid *fid)
+{
+	return IS_ERR(fid) ? fid :  p9_client_walk(fid, 0, NULL, 1);
+}
+static inline struct p9_fid *v9fs_fid_clone(struct dentry *dentry)
+{
+	return clone_fid(v9fs_fid_lookup(dentry));
+}
 #endif

fs/9p/vfs_inode.c

@@ -661,7 +661,7 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 	}
 
 	/* clone a fid to use for creation */
-	ofid = p9_client_walk(dfid, 0, NULL, 1);
+	ofid = clone_fid(dfid);
 	if (IS_ERR(ofid)) {
 		err = PTR_ERR(ofid);
 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
@@ -975,13 +975,13 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	if (IS_ERR(oldfid))
 		return PTR_ERR(oldfid);
 
-	olddirfid = v9fs_parent_fid(old_dentry);
+	olddirfid = clone_fid(v9fs_parent_fid(old_dentry));
 	if (IS_ERR(olddirfid)) {
 		retval = PTR_ERR(olddirfid);
 		goto done;
 	}
 
-	newdirfid = v9fs_parent_fid(new_dentry);
+	newdirfid = clone_fid(v9fs_parent_fid(new_dentry));
 	if (IS_ERR(newdirfid)) {
 		retval = PTR_ERR(newdirfid);
 		goto clunk_olddir;

fs/9p/vfs_inode_dotl.c

@@ -281,7 +281,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 	}
 
 	/* clone a fid to use for creation */
-	ofid = p9_client_walk(dfid, 0, NULL, 1);
+	ofid = clone_fid(dfid);
 	if (IS_ERR(ofid)) {
 		err = PTR_ERR(ofid);
 		p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);

fs/9p/xattr.c

@@ -97,8 +97,6 @@ int v9fs_xattr_set(struct dentry *dentry, const char *name,
 		   const void *value, size_t value_len, int flags)
 {
 	struct p9_fid *fid = v9fs_fid_lookup(dentry);
-	if (IS_ERR(fid))
-		return PTR_ERR(fid);
 	return v9fs_fid_xattr_set(fid, name, value, value_len, flags);
 }
 
@@ -115,7 +113,7 @@ int v9fs_fid_xattr_set(struct p9_fid *fid, const char *name,
 		 name, value_len, flags);
 
 	/* Clone it */
-	fid = p9_client_walk(fid, 0, NULL, 1);
+	fid = clone_fid(fid);
 	if (IS_ERR(fid))
 		return PTR_ERR(fid);
 

fs/adfs/dir.c

@@ -227,7 +227,7 @@ adfs_hash(const struct dentry *parent, struct qstr *qstr)
  * requirements of the underlying filesystem.
  */
 static int
-adfs_compare(const struct dentry *parent, const struct dentry *dentry,
+adfs_compare(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
 	int i;

fs/affs/amigaffs.c

@@ -472,9 +472,7 @@ affs_warning(struct super_block *sb, const char *function, const char *fmt, ...)
 bool
 affs_nofilenametruncate(const struct dentry *dentry)
 {
-	struct inode *inode = d_inode(dentry);
-
-	return affs_test_opt(AFFS_SB(inode->i_sb)->s_flags, SF_NO_TRUNCATE);
+	return affs_test_opt(AFFS_SB(dentry->d_sb)->s_flags, SF_NO_TRUNCATE);
 }
 
 /* Check if the name is valid for a affs object. */

fs/affs/namei.c

@@ -14,11 +14,11 @@ typedef int (*toupper_t)(int);
 
 static int	 affs_toupper(int ch);
 static int	 affs_hash_dentry(const struct dentry *, struct qstr *);
-static int       affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+static int       affs_compare_dentry(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name);
 static int	 affs_intl_toupper(int ch);
 static int	 affs_intl_hash_dentry(const struct dentry *, struct qstr *);
-static int       affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+static int       affs_intl_compare_dentry(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name);
 
 const struct dentry_operations affs_dentry_operations = {
@@ -131,20 +131,20 @@ static inline int __affs_compare_dentry(unsigned int len,
 }
 
 static int
-affs_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+affs_compare_dentry(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
 
 	return __affs_compare_dentry(len, str, name, affs_toupper,
-				     affs_nofilenametruncate(parent));
+				     affs_nofilenametruncate(dentry));
 }
 
 static int
-affs_intl_compare_dentry(const struct dentry *parent, const struct dentry *dentry,
+affs_intl_compare_dentry(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
 	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
-				     affs_nofilenametruncate(parent));
+				     affs_nofilenametruncate(dentry));
 
 }
 

fs/cachefiles/namei.c

@@ -263,6 +263,8 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
 				     struct cachefiles_object *object)
 {
+	blkcnt_t i_blocks = d_backing_inode(object->dentry)->i_blocks;
+
 	write_lock(&cache->active_lock);
 	rb_erase(&object->active_node, &cache->active_nodes);
 	clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
@@ -273,8 +275,7 @@ void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
 	/* This object can now be culled, so we need to let the daemon know
 	 * that there is something it can remove if it needs to.
 	 */
-	atomic_long_add(d_backing_inode(object->dentry)->i_blocks,
-			&cache->b_released);
+	atomic_long_add(i_blocks, &cache->b_released);
 	if (atomic_inc_return(&cache->f_released))
 		cachefiles_state_changed(cache);
 }

fs/cifs/dir.c

@@ -903,10 +903,10 @@ static int cifs_ci_hash(const struct dentry *dentry, struct qstr *q)
 	return 0;
 }
 
-static int cifs_ci_compare(const struct dentry *parent, const struct dentry *dentry,
+static int cifs_ci_compare(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct nls_table *codepage = CIFS_SB(parent->d_sb)->local_nls;
+	struct nls_table *codepage = CIFS_SB(dentry->d_sb)->local_nls;
 	wchar_t c1, c2;
 	int i, l1, l2;
 

fs/dcache.c

@@ -316,20 +316,6 @@ static void dentry_free(struct dentry *dentry)
 		call_rcu(&dentry->d_u.d_rcu, __d_free);
 }
 
-/**
- * dentry_rcuwalk_invalidate - invalidate in-progress rcu-walk lookups
- * @dentry: the target dentry
- * After this call, in-progress rcu-walk path lookup will fail. This
- * should be called after unhashing, and after changing d_inode (if
- * the dentry has not already been unhashed).
- */
-static inline void dentry_rcuwalk_invalidate(struct dentry *dentry)
-{
-	lockdep_assert_held(&dentry->d_lock);
-	/* Go through am invalidation barrier */
-	write_seqcount_invalidate(&dentry->d_seq);
-}
-
 /*
  * Release the dentry's inode, using the filesystem
  * d_iput() operation if defined.
@@ -468,7 +454,8 @@ void __d_drop(struct dentry *dentry)
 		__hlist_bl_del(&dentry->d_hash);
 		dentry->d_hash.pprev = NULL;
 		hlist_bl_unlock(b);
-		dentry_rcuwalk_invalidate(dentry);
+		/* After this call, in-progress rcu-walk path lookup will fail. */
+		write_seqcount_invalidate(&dentry->d_seq);
 	}
 }
 EXPORT_SYMBOL(__d_drop);
@@ -2060,7 +2047,7 @@ static inline bool d_same_name(const struct dentry *dentry,
 			return false;
 		return dentry_cmp(dentry, name->name, name->len) == 0;
 	}
-	return parent->d_op->d_compare(parent, dentry,
+	return parent->d_op->d_compare(dentry,
 				       dentry->d_name.len, dentry->d_name.name,
 				       name) == 0;
 }
@@ -2163,7 +2150,7 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent,
 				cpu_relax();
 				goto seqretry;
 			}
-			if (parent->d_op->d_compare(parent, dentry,
+			if (parent->d_op->d_compare(dentry,
 						    tlen, tname, name) != 0)
 				continue;
 		} else {
@@ -2352,19 +2339,15 @@ void d_delete(struct dentry * dentry)
 }
 EXPORT_SYMBOL(d_delete);
 
-static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
+static void __d_rehash(struct dentry *entry)
 {
+	struct hlist_bl_head *b = d_hash(entry->d_name.hash);
 	BUG_ON(!d_unhashed(entry));
 	hlist_bl_lock(b);
 	hlist_bl_add_head_rcu(&entry->d_hash, b);
 	hlist_bl_unlock(b);
 }
 
-static void _d_rehash(struct dentry * entry)
-{
-	__d_rehash(entry, d_hash(entry->d_name.hash));
-}
-
 /**
  * d_rehash	- add an entry back to the hash
  * @entry: dentry to add to the hash
@@ -2375,7 +2358,7 @@ static void _d_rehash(struct dentry * entry)
 void d_rehash(struct dentry * entry)
 {
 	spin_lock(&entry->d_lock);
-	_d_rehash(entry);
+	__d_rehash(entry);
 	spin_unlock(&entry->d_lock);
 }
 EXPORT_SYMBOL(d_rehash);
@@ -2549,7 +2532,7 @@ static inline void __d_add(struct dentry *dentry, struct inode *inode)
 		raw_write_seqcount_end(&dentry->d_seq);
 		fsnotify_update_flags(dentry);
 	}
-	_d_rehash(dentry);
+	__d_rehash(dentry);
 	if (dir)
 		end_dir_add(dir, n);
 	spin_unlock(&dentry->d_lock);
@@ -2611,7 +2594,7 @@ struct dentry *d_exact_alias(struct dentry *entry, struct inode *inode)
 			alias = NULL;
 		} else {
 			__dget_dlock(alias);
-			_d_rehash(alias);
+			__d_rehash(alias);
 			spin_unlock(&alias->d_lock);
 		}
 		spin_unlock(&inode->i_lock);
@@ -2795,30 +2778,22 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
 	write_seqcount_begin(&dentry->d_seq);
 	write_seqcount_begin_nested(&target->d_seq, DENTRY_D_LOCK_NESTED);
 
+	/* unhash both */
 	/* __d_drop does write_seqcount_barrier, but they're OK to nest. */
-
-	/*
-	 * Move the dentry to the target hash queue. Don't bother checking
-	 * for the same hash queue because of how unlikely it is.
-	 */
 	__d_drop(dentry);
-	__d_rehash(dentry, d_hash(target->d_name.hash));
-
-	/*
-	 * Unhash the target (d_delete() is not usable here).  If exchanging
-	 * the two dentries, then rehash onto the other's hash queue.
-	 */
 	__d_drop(target);
-	if (exchange) {
-		__d_rehash(target, d_hash(dentry->d_name.hash));
-	}
 
 	/* Switch the names.. */
 	if (exchange)
 		swap_names(dentry, target);
 	else
 		copy_name(dentry, target);
 
+	/* rehash in new place(s) */
+	__d_rehash(dentry);
+	if (exchange)
+		__d_rehash(target);
+
 	/* ... and switch them in the tree */
 	if (IS_ROOT(dentry)) {
 		/* splicing a tree */

fs/efivarfs/super.c

@@ -45,8 +45,7 @@ static struct super_block *efivarfs_sb;
  * So we need to perform a case-sensitive match on part 1 and a
  * case-insensitive match on part 2.
  */
-static int efivarfs_d_compare(const struct dentry *parent,
-			      const struct dentry *dentry,
+static int efivarfs_d_compare(const struct dentry *dentry,
 			      unsigned int len, const char *str,
 			      const struct qstr *name)
 {

fs/fat/namei_msdos.c

@@ -162,10 +162,10 @@ static int msdos_hash(const struct dentry *dentry, struct qstr *qstr)
  * Compare two msdos names. If either of the names are invalid,
  * we fall back to doing the standard name comparison.
  */
-static int msdos_cmp(const struct dentry *parent, const struct dentry *dentry,
+static int msdos_cmp(const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
 {
-	struct fat_mount_options *options = &MSDOS_SB(parent->d_sb)->options;
+	struct fat_mount_options *options = &MSDOS_SB(dentry->d_sb)->options;
 	unsigned char a_msdos_name[MSDOS_NAME], b_msdos_name[MSDOS_NAME];
 	int error;