From b0c6108ecf64fce3987f80c1610472a56d480d9a Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Wed, 16 May 2018 10:55:01 -0400
Subject: nfs_instantiate(): prevent multiple aliases for directory inode

Since NFS allows open-by-fhandle, we have to cope with the possibility
of mkdir vs. open-by-guessed-handle races.  A local filesystem could
decide what the inumber of the new object will be and insert a locked
inode with that inumber into icache _before_ the on-disk data structures
begin to look good and unlock it only once it has a dentry alias, so
that open-by-handle coming first would quietly fail and mkdir coming
first would have open-by-handle grab its dentry.

For NFS it's a non-starter - the icache key is server-supplied fhandle
and we do not get that until the object has been fully created on server.
We really have to deal with the possibility that open-by-handle gets
the in-core inode and attaches a dentry to it before mkdir does.

Solution: let nfs_mkdir() use d_splice_alias() to catch those.  We can
	* get an error.  Just return it to our caller.
	* get NULL - no preexisting dentry aliases, we'd just done what
d_add() would've done.  Success.
	* get a reference to preexisting alias.  In that case the alias
had been moved in place of nfs_mkdir() argument (and hashed there), while
nfs_mkdir() argument is left unhashed negative.  Which is just fine for
->mkdir() callers, all we need is to release the reference we'd got from
d_splice_alias() and report success.

Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/dir.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 7a9c14426855..df6fd4e5b068 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1641,6 +1641,7 @@ int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
 	struct dentry *parent = dget_parent(dentry);
 	struct inode *dir = d_inode(parent);
 	struct inode *inode;
+	struct dentry *d;
 	int error = -EACCES;
 
 	d_drop(dentry);
@@ -1662,10 +1663,12 @@ int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
 			goto out_error;
 	}
 	inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
-	error = PTR_ERR(inode);
-	if (IS_ERR(inode))
+	d = d_splice_alias(inode, dentry);
+	if (IS_ERR(d)) {
+		error = PTR_ERR(d);
 		goto out_error;
-	d_add(dentry, inode);
+	}
+	dput(d);
 out:
 	dput(parent);
 	return 0;
-- 
cgit v1.2.3-55-g7522


From c971e6a006175bd0f195c6346c4e8bc4089bec00 Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Mon, 28 May 2018 18:27:19 -0400
Subject: kill d_instantiate_no_diralias()

The only user is fuse_create_new_entry(), and there it's used to
mitigate the same mkdir/open-by-handle race as in nfs_mkdir().
The same solution applies - unhash the mkdir argument, then
call d_splice_alias() and if that returns a reference to preexisting
alias, dput() and report success.  ->mkdir() argument left unhashed
negative with the preexisting alias moved in the right place is just
fine from the ->mkdir() callers point of view.

Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c            | 27 ---------------------------
 fs/fuse/dir.c          | 15 +++++++++++----
 include/linux/dcache.h |  1 -
 3 files changed, 11 insertions(+), 32 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 0e8e5de3c48a..a7d9e7a4c283 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1899,33 +1899,6 @@ void d_instantiate_new(struct dentry *entry, struct inode *inode)
 }
 EXPORT_SYMBOL(d_instantiate_new);
 
-/**
- * d_instantiate_no_diralias - instantiate a non-aliased dentry
- * @entry: dentry to complete
- * @inode: inode to attach to this dentry
- *
- * Fill in inode information in the entry.  If a directory alias is found, then
- * return an error (and drop inode).  Together with d_materialise_unique() this
- * guarantees that a directory inode may never have more than one alias.
- */
-int d_instantiate_no_diralias(struct dentry *entry, struct inode *inode)
-{
-	BUG_ON(!hlist_unhashed(&entry->d_u.d_alias));
-
-	security_d_instantiate(entry, inode);
-	spin_lock(&inode->i_lock);
-	if (S_ISDIR(inode->i_mode) && !hlist_empty(&inode->i_dentry)) {
-		spin_unlock(&inode->i_lock);
-		iput(inode);
-		return -EBUSY;
-	}
-	__d_instantiate(entry, inode);
-	spin_unlock(&inode->i_lock);
-
-	return 0;
-}
-EXPORT_SYMBOL(d_instantiate_no_diralias);
-
 struct dentry *d_make_root(struct inode *root_inode)
 {
 	struct dentry *res = NULL;
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 56231b31f806..4bbae6ac75c3 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -539,6 +539,7 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
 {
 	struct fuse_entry_out outarg;
 	struct inode *inode;
+	struct dentry *d;
 	int err;
 	struct fuse_forget_link *forget;
 
@@ -570,11 +571,17 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
 	}
 	kfree(forget);
 
-	err = d_instantiate_no_diralias(entry, inode);
-	if (err)
-		return err;
+	d_drop(entry);
+	d = d_splice_alias(inode, entry);
+	if (IS_ERR(d))
+		return PTR_ERR(d);
 
-	fuse_change_entry_timeout(entry, &outarg);
+	if (d) {
+		fuse_change_entry_timeout(d, &outarg);
+		dput(d);
+	} else {
+		fuse_change_entry_timeout(entry, &outarg);
+	}
 	fuse_invalidate_attr(dir);
 	return 0;
 
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 66c6e17e61e5..0b83629a3d8f 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -227,7 +227,6 @@ extern void d_instantiate(struct dentry *, struct inode *);
 extern void d_instantiate_new(struct dentry *, struct inode *);
 extern struct dentry * d_instantiate_unique(struct dentry *, struct inode *);
 extern struct dentry * d_instantiate_anon(struct dentry *, struct inode *);
-extern int d_instantiate_no_diralias(struct dentry *, struct inode *);
 extern void __d_drop(struct dentry *dentry);
 extern void d_drop(struct dentry *dentry);
 extern void d_delete(struct dentry *);
-- 
cgit v1.2.3-55-g7522


From c2b6d621c4ffe9936adf7a55c8b1c769672c306f Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Thu, 28 Jun 2018 15:53:17 -0400
Subject: new primitive: discard_new_inode()

	We don't want open-by-handle picking half-set-up in-core
struct inode from e.g. mkdir() having failed halfway through.
In other words, we don't want such inodes returned by iget_locked()
on their way to extinction.  However, we can't just have them
unhashed - otherwise open-by-handle immediately *after* that would've
ended up creating a new in-core inode over the on-disk one that
is in process of being freed right under us.

	Solution: new flag (I_CREATING) set by insert_inode_locked() and
removed by unlock_new_inode() and a new primitive (discard_new_inode())
to be used by such halfway-through-setup failure exits instead of
unlock_new_inode() / iput() combinations.  That primitive unlocks new
inode, but leaves I_CREATING in place.

	iget_locked() treats finding an I_CREATING inode as failure
(-ESTALE, once we sort out the error propagation).
	insert_inode_locked() treats the same as instant -EBUSY.
	ilookup() treats those as icache miss.

[Fix by Dan Carpenter <dan.carpenter@oracle.com> folded in]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/dcache.c        |  2 +-
 fs/inode.c         | 45 +++++++++++++++++++++++++++++++++++++++++----
 include/linux/fs.h |  6 +++++-
 3 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index a7d9e7a4c283..11b753d29409 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1892,7 +1892,7 @@ void d_instantiate_new(struct dentry *entry, struct inode *inode)
 	spin_lock(&inode->i_lock);
 	__d_instantiate(entry, inode);
 	WARN_ON(!(inode->i_state & I_NEW));
-	inode->i_state &= ~I_NEW;
+	inode->i_state &= ~I_NEW & ~I_CREATING;
 	smp_mb();
 	wake_up_bit(&inode->i_state, __I_NEW);
 	spin_unlock(&inode->i_lock);
diff --git a/fs/inode.c b/fs/inode.c
index 2c300e981796..6cd2e7ba9f4d 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -804,6 +804,10 @@ repeat:
 			__wait_on_freeing_inode(inode);
 			goto repeat;
 		}
+		if (unlikely(inode->i_state & I_CREATING)) {
+			spin_unlock(&inode->i_lock);
+			return ERR_PTR(-ESTALE);
+		}
 		__iget(inode);
 		spin_unlock(&inode->i_lock);
 		return inode;
@@ -831,6 +835,10 @@ repeat:
 			__wait_on_freeing_inode(inode);
 			goto repeat;
 		}
+		if (unlikely(inode->i_state & I_CREATING)) {
+			spin_unlock(&inode->i_lock);
+			return ERR_PTR(-ESTALE);
+		}
 		__iget(inode);
 		spin_unlock(&inode->i_lock);
 		return inode;
@@ -961,13 +969,26 @@ void unlock_new_inode(struct inode *inode)
 	lockdep_annotate_inode_mutex_key(inode);
 	spin_lock(&inode->i_lock);
 	WARN_ON(!(inode->i_state & I_NEW));
-	inode->i_state &= ~I_NEW;
+	inode->i_state &= ~I_NEW & ~I_CREATING;
 	smp_mb();
 	wake_up_bit(&inode->i_state, __I_NEW);
 	spin_unlock(&inode->i_lock);
 }
 EXPORT_SYMBOL(unlock_new_inode);
 
+void discard_new_inode(struct inode *inode)
+{
+	lockdep_annotate_inode_mutex_key(inode);
+	spin_lock(&inode->i_lock);
+	WARN_ON(!(inode->i_state & I_NEW));
+	inode->i_state &= ~I_NEW;
+	smp_mb();
+	wake_up_bit(&inode->i_state, __I_NEW);
+	spin_unlock(&inode->i_lock);
+	iput(inode);
+}
+EXPORT_SYMBOL(discard_new_inode);
+
 /**
  * lock_two_nondirectories - take two i_mutexes on non-directory objects
  *
@@ -1039,6 +1060,8 @@ again:
 		 * Use the old inode instead of the preallocated one.
 		 */
 		spin_unlock(&inode_hash_lock);
+		if (IS_ERR(old))
+			return NULL;
 		wait_on_inode(old);
 		if (unlikely(inode_unhashed(old))) {
 			iput(old);
@@ -1128,6 +1151,8 @@ again:
 	inode = find_inode_fast(sb, head, ino);
 	spin_unlock(&inode_hash_lock);
 	if (inode) {
+		if (IS_ERR(inode))
+			return NULL;
 		wait_on_inode(inode);
 		if (unlikely(inode_unhashed(inode))) {
 			iput(inode);
@@ -1165,6 +1190,8 @@ again:
 		 */
 		spin_unlock(&inode_hash_lock);
 		destroy_inode(inode);
+		if (IS_ERR(old))
+			return NULL;
 		inode = old;
 		wait_on_inode(inode);
 		if (unlikely(inode_unhashed(inode))) {
@@ -1282,7 +1309,7 @@ struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval,
 	inode = find_inode(sb, head, test, data);
 	spin_unlock(&inode_hash_lock);
 
-	return inode;
+	return IS_ERR(inode) ? NULL : inode;
 }
 EXPORT_SYMBOL(ilookup5_nowait);
 
@@ -1338,6 +1365,8 @@ again:
 	spin_unlock(&inode_hash_lock);
 
 	if (inode) {
+		if (IS_ERR(inode))
+			return NULL;
 		wait_on_inode(inode);
 		if (unlikely(inode_unhashed(inode))) {
 			iput(inode);
@@ -1421,12 +1450,17 @@ int insert_inode_locked(struct inode *inode)
 		}
 		if (likely(!old)) {
 			spin_lock(&inode->i_lock);
-			inode->i_state |= I_NEW;
+			inode->i_state |= I_NEW | I_CREATING;
 			hlist_add_head(&inode->i_hash, head);
 			spin_unlock(&inode->i_lock);
 			spin_unlock(&inode_hash_lock);
 			return 0;
 		}
+		if (unlikely(old->i_state & I_CREATING)) {
+			spin_unlock(&old->i_lock);
+			spin_unlock(&inode_hash_lock);
+			return -EBUSY;
+		}
 		__iget(old);
 		spin_unlock(&old->i_lock);
 		spin_unlock(&inode_hash_lock);
@@ -1443,7 +1477,10 @@ EXPORT_SYMBOL(insert_inode_locked);
 int insert_inode_locked4(struct inode *inode, unsigned long hashval,
 		int (*test)(struct inode *, void *), void *data)
 {
-	struct inode *old = inode_insert5(inode, hashval, test, NULL, data);
+	struct inode *old;
+
+	inode->i_state |= I_CREATING;
+	old = inode_insert5(inode, hashval, test, NULL, data);
 
 	if (old != inode) {
 		iput(old);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5c91108846db..a42600565925 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2016,6 +2016,8 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
  * I_OVL_INUSE		Used by overlayfs to get exclusive ownership on upper
  *			and work dirs among overlayfs mounts.
  *
+ * I_CREATING		New object's inode in the middle of setting up.
+ *
  * Q: What is the difference between I_WILL_FREE and I_FREEING?
  */
 #define I_DIRTY_SYNC		(1 << 0)
@@ -2036,7 +2038,8 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
 #define __I_DIRTY_TIME_EXPIRED	12
 #define I_DIRTY_TIME_EXPIRED	(1 << __I_DIRTY_TIME_EXPIRED)
 #define I_WB_SWITCH		(1 << 13)
-#define I_OVL_INUSE			(1 << 14)
+#define I_OVL_INUSE		(1 << 14)
+#define I_CREATING		(1 << 15)
 
 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
@@ -2919,6 +2922,7 @@ extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
 #endif
 extern void unlock_new_inode(struct inode *);
+extern void discard_new_inode(struct inode *);
 extern unsigned int get_next_ino(void);
 extern void evict_inodes(struct super_block *sb);
 
-- 
cgit v1.2.3-55-g7522


From 32955c5422a8a5460bbefe2a6fc51eadcafff4c9 Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Wed, 16 May 2018 12:20:05 -0400
Subject: btrfs: switch to discard_new_inode()

Make sure that no partially set up inodes can be returned by
open-by-handle.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/inode.c | 106 ++++++++++++++++++++-----------------------------------
 1 file changed, 39 insertions(+), 67 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e9482f0db9d0..9382e0881900 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6335,8 +6335,10 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	location->type = BTRFS_INODE_ITEM_KEY;
 
 	ret = btrfs_insert_inode_locked(inode);
-	if (ret < 0)
+	if (ret < 0) {
+		iput(inode);
 		goto fail;
+	}
 
 	path->leave_spinning = 1;
 	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
@@ -6395,12 +6397,11 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
 	return inode;
 
 fail_unlock:
-	unlock_new_inode(inode);
+	discard_new_inode(inode);
 fail:
 	if (dir && name)
 		BTRFS_I(dir)->index_cnt--;
 	btrfs_free_path(path);
-	iput(inode);
 	return ERR_PTR(ret);
 }
 
@@ -6505,7 +6506,6 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 	struct btrfs_root *root = BTRFS_I(dir)->root;
 	struct inode *inode = NULL;
 	int err;
-	int drop_inode = 0;
 	u64 objectid;
 	u64 index = 0;
 
@@ -6527,6 +6527,7 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 			mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
+		inode = NULL;
 		goto out_unlock;
 	}
 
@@ -6541,31 +6542,24 @@ static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
 
 	err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
 	if (err)
-		goto out_unlock_inode;
+		goto out_unlock;
 
 	err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
 			0, index);
-	if (err) {
-		goto out_unlock_inode;
-	} else {
-		btrfs_update_inode(trans, root, inode);
-		d_instantiate_new(dentry, inode);
-	}
+	if (err)
+		goto out_unlock;
+
+	btrfs_update_inode(trans, root, inode);
+	d_instantiate_new(dentry, inode);
 
 out_unlock:
 	btrfs_end_transaction(trans);
 	btrfs_btree_balance_dirty(fs_info);
-	if (drop_inode) {
+	if (err && inode) {
 		inode_dec_link_count(inode);
-		iput(inode);
+		discard_new_inode(inode);
 	}
 	return err;
-
-out_unlock_inode:
-	drop_inode = 1;
-	unlock_new_inode(inode);
-	goto out_unlock;
-
 }
 
 static int btrfs_create(struct inode *dir, struct dentry *dentry,
@@ -6575,7 +6569,6 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 	struct btrfs_trans_handle *trans;
 	struct btrfs_root *root = BTRFS_I(dir)->root;
 	struct inode *inode = NULL;
-	int drop_inode_on_err = 0;
 	int err;
 	u64 objectid;
 	u64 index = 0;
@@ -6598,9 +6591,9 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 			mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
+		inode = NULL;
 		goto out_unlock;
 	}
-	drop_inode_on_err = 1;
 	/*
 	* If the active LSM wants to access the inode during
 	* d_instantiate it needs these. Smack checks to see
@@ -6613,33 +6606,28 @@ static int btrfs_create(struct inode *dir, struct dentry *dentry,
 
 	err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
 	if (err)
-		goto out_unlock_inode;
+		goto out_unlock;
 
 	err = btrfs_update_inode(trans, root, inode);
 	if (err)
-		goto out_unlock_inode;
+		goto out_unlock;
 
 	err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
 			0, index);
 	if (err)
-		goto out_unlock_inode;
+		goto out_unlock;
 
 	BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
 	d_instantiate_new(dentry, inode);
 
 out_unlock:
 	btrfs_end_transaction(trans);
-	if (err && drop_inode_on_err) {
+	if (err && inode) {
 		inode_dec_link_count(inode);
-		iput(inode);
+		discard_new_inode(inode);
 	}
 	btrfs_btree_balance_dirty(fs_info);
 	return err;
-
-out_unlock_inode:
-	unlock_new_inode(inode);
-	goto out_unlock;
-
 }
 
 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
@@ -6748,6 +6736,7 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 			S_IFDIR | mode, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
+		inode = NULL;
 		goto out_fail;
 	}
 
@@ -6758,34 +6747,30 @@ static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 
 	err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
 	if (err)
-		goto out_fail_inode;
+		goto out_fail;
 
 	btrfs_i_size_write(BTRFS_I(inode), 0);
 	err = btrfs_update_inode(trans, root, inode);
 	if (err)
-		goto out_fail_inode;
+		goto out_fail;
 
 	err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
 			dentry->d_name.name,
 			dentry->d_name.len, 0, index);
 	if (err)
-		goto out_fail_inode;
+		goto out_fail;
 
 	d_instantiate_new(dentry, inode);
 	drop_on_err = 0;
 
 out_fail:
 	btrfs_end_transaction(trans);
-	if (drop_on_err) {
+	if (err && inode) {
 		inode_dec_link_count(inode);
-		iput(inode);
+		discard_new_inode(inode);
 	}
 	btrfs_btree_balance_dirty(fs_info);
 	return err;
-
-out_fail_inode:
-	unlock_new_inode(inode);
-	goto out_fail;
 }
 
 static noinline int uncompress_inline(struct btrfs_path *path,
@@ -10112,7 +10097,6 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 	struct btrfs_key key;
 	struct inode *inode = NULL;
 	int err;
-	int drop_inode = 0;
 	u64 objectid;
 	u64 index = 0;
 	int name_len;
@@ -10145,6 +10129,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 				objectid, S_IFLNK|S_IRWXUGO, &index);
 	if (IS_ERR(inode)) {
 		err = PTR_ERR(inode);
+		inode = NULL;
 		goto out_unlock;
 	}
 
@@ -10161,12 +10146,12 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 
 	err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
 	if (err)
-		goto out_unlock_inode;
+		goto out_unlock;
 
 	path = btrfs_alloc_path();
 	if (!path) {
 		err = -ENOMEM;
-		goto out_unlock_inode;
+		goto out_unlock;
 	}
 	key.objectid = btrfs_ino(BTRFS_I(inode));
 	key.offset = 0;
@@ -10176,7 +10161,7 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 				      datasize);
 	if (err) {
 		btrfs_free_path(path);
-		goto out_unlock_inode;
+		goto out_unlock;
 	}
 	leaf = path->nodes[0];
 	ei = btrfs_item_ptr(leaf, path->slots[0],
@@ -10208,26 +10193,19 @@ static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
 	if (!err)
 		err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
 				BTRFS_I(inode), 0, index);
-	if (err) {
-		drop_inode = 1;
-		goto out_unlock_inode;
-	}
+	if (err)
+		goto out_unlock;
 
 	d_instantiate_new(dentry, inode);
 
 out_unlock:
 	btrfs_end_transaction(trans);
-	if (drop_inode) {
+	if (err && inode) {
 		inode_dec_link_count(inode);
-		iput(inode);
+		discard_new_inode(inode);
 	}
 	btrfs_btree_balance_dirty(fs_info);
 	return err;
-
-out_unlock_inode:
-	drop_inode = 1;
-	unlock_new_inode(inode);
-	goto out_unlock;
 }
 
 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
@@ -10436,14 +10414,14 @@ static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 
 	ret = btrfs_init_inode_security(trans, inode, dir, NULL);
 	if (ret)
-		goto out_inode;
+		goto out;
 
 	ret = btrfs_update_inode(trans, root, inode);
 	if (ret)
-		goto out_inode;
+		goto out;
 	ret = btrfs_orphan_add(trans, BTRFS_I(inode));
 	if (ret)
-		goto out_inode;
+		goto out;
 
 	/*
 	 * We set number of links to 0 in btrfs_new_inode(), and here we set
@@ -10453,21 +10431,15 @@ static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 	 *    d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
 	 */
 	set_nlink(inode, 1);
-	unlock_new_inode(inode);
 	d_tmpfile(dentry, inode);
+	unlock_new_inode(inode);
 	mark_inode_dirty(inode);
-
 out:
 	btrfs_end_transaction(trans);
-	if (ret)
-		iput(inode);
+	if (ret && inode)
+		discard_new_inode(inode);
 	btrfs_btree_balance_dirty(fs_info);
 	return ret;
-
-out_inode:
-	unlock_new_inode(inode);
-	goto out;
-
 }
 
 __attribute__((const))
-- 
cgit v1.2.3-55-g7522


From dd54992776ebb44519ba4cd69145c4f19d166ddb Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Wed, 16 May 2018 12:22:50 -0400
Subject: ufs: switch to discard_new_inode()

we don't want open-by-handle to pick an in-core inode that
has failed setup halfway through.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/ufs/ialloc.c | 3 +--
 fs/ufs/namei.c  | 9 +++------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
index e1ef0f0a1353..02c0a4be4212 100644
--- a/fs/ufs/ialloc.c
+++ b/fs/ufs/ialloc.c
@@ -343,8 +343,7 @@ cg_found:
 fail_remove_inode:
 	mutex_unlock(&sbi->s_lock);
 	clear_nlink(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	UFSD("EXIT (FAILED): err %d\n", err);
 	return ERR_PTR(err);
 failed:
diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c
index d5f43ba76c59..9ef40f100415 100644
--- a/fs/ufs/namei.c
+++ b/fs/ufs/namei.c
@@ -43,8 +43,7 @@ static inline int ufs_add_nondir(struct dentry *dentry, struct inode *inode)
 		return 0;
 	}
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	return err;
 }
 
@@ -142,8 +141,7 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry,
 
 out_fail:
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	return err;
 }
 
@@ -198,8 +196,7 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
 out_fail:
 	inode_dec_link_count(inode);
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput (inode);
+	discard_new_inode(inode);
 out_dir:
 	inode_dec_link_count(dir);
 	return err;
-- 
cgit v1.2.3-55-g7522


From 5c1a68a358f94b9ac2e33183327bc04f207feed2 Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Wed, 16 May 2018 12:25:39 -0400
Subject: udf: switch to discard_new_inode()

we don't want open-by-handle to pick an in-core inode that
has failed setup halfway through.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/udf/namei.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index c586026508db..061d049c2620 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -608,8 +608,7 @@ static int udf_add_nondir(struct dentry *dentry, struct inode *inode)
 	fi = udf_add_entry(dir, dentry, &fibh, &cfi, &err);
 	if (unlikely(!fi)) {
 		inode_dec_link_count(inode);
-		unlock_new_inode(inode);
-		iput(inode);
+		discard_new_inode(inode);
 		return err;
 	}
 	cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
@@ -700,8 +699,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	fi = udf_add_entry(inode, NULL, &fibh, &cfi, &err);
 	if (!fi) {
 		inode_dec_link_count(inode);
-		unlock_new_inode(inode);
-		iput(inode);
+		discard_new_inode(inode);
 		goto out;
 	}
 	set_nlink(inode, 2);
@@ -719,8 +717,7 @@ static int udf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	if (!fi) {
 		clear_nlink(inode);
 		mark_inode_dirty(inode);
-		unlock_new_inode(inode);
-		iput(inode);
+		discard_new_inode(inode);
 		goto out;
 	}
 	cfi.icb.extLength = cpu_to_le32(inode->i_sb->s_blocksize);
@@ -1047,8 +1044,7 @@ out:
 out_no_entry:
 	up_write(&iinfo->i_data_sem);
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	goto out;
 }
 
-- 
cgit v1.2.3-55-g7522


From 2e5afe54e0cd6fce79b51ca547caf08a990ad56d Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Wed, 16 May 2018 18:29:56 -0400
Subject: ext2: make sure that partially set up inodes won't be returned by
 ext2_iget()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/ext2/ialloc.c | 3 +--
 fs/ext2/namei.c  | 9 +++------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index 6484199b35d1..5c3d7b7e4975 100644
--- a/fs/ext2/ialloc.c
+++ b/fs/ext2/ialloc.c
@@ -611,8 +611,7 @@ fail_drop:
 	dquot_drop(inode);
 	inode->i_flags |= S_NOQUOTA;
 	clear_nlink(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	return ERR_PTR(err);
 
 fail:
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 152453a91877..0c26dcc5d850 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -45,8 +45,7 @@ static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
 		return 0;
 	}
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 	return err;
 }
 
@@ -192,8 +191,7 @@ out:
 
 out_fail:
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput (inode);
+	discard_new_inode(inode);
 	goto out;
 }
 
@@ -261,8 +259,7 @@ out:
 out_fail:
 	inode_dec_link_count(inode);
 	inode_dec_link_count(inode);
-	unlock_new_inode(inode);
-	iput(inode);
+	discard_new_inode(inode);
 out_dir:
 	inode_dec_link_count(dir);
 	goto out;
-- 
cgit v1.2.3-55-g7522


From a6cbedfa8783b42b9272c05297865bdb501005cb Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Fri, 29 Jun 2018 11:59:37 -0400
Subject: jfs: switch to discard_new_inode()

we don't want open-by-handle to pick an in-core inode that
has failed setup halfway through.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/jfs/jfs_inode.c |  8 ++++----
 fs/jfs/namei.c     | 12 ++++--------
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/fs/jfs/jfs_inode.c b/fs/jfs/jfs_inode.c
index 5e9b7bb3aabf..96732c24b054 100644
--- a/fs/jfs/jfs_inode.c
+++ b/fs/jfs/jfs_inode.c
@@ -61,8 +61,7 @@ struct inode *ialloc(struct inode *parent, umode_t mode)
 	inode = new_inode(sb);
 	if (!inode) {
 		jfs_warn("ialloc: new_inode returned NULL!");
-		rc = -ENOMEM;
-		goto fail;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	jfs_inode = JFS_IP(inode);
@@ -141,9 +140,10 @@ fail_drop:
 	dquot_drop(inode);
 	inode->i_flags |= S_NOQUOTA;
 	clear_nlink(inode);
-	unlock_new_inode(inode);
+	discard_new_inode(inode);
+	return ERR_PTR(rc);
+
 fail_put:
 	iput(inode);
-fail:
 	return ERR_PTR(rc);
 }
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 56c3fcbfe80e..14528c0ffe63 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -175,8 +175,7 @@ static int jfs_create(struct inode *dip, struct dentry *dentry, umode_t mode,
 	if (rc) {
 		free_ea_wmap(ip);
 		clear_nlink(ip);
-		unlock_new_inode(ip);
-		iput(ip);
+		discard_new_inode(ip);
 	} else {
 		d_instantiate_new(dentry, ip);
 	}
@@ -309,8 +308,7 @@ static int jfs_mkdir(struct inode *dip, struct dentry *dentry, umode_t mode)
 	if (rc) {
 		free_ea_wmap(ip);
 		clear_nlink(ip);
-		unlock_new_inode(ip);
-		iput(ip);
+		discard_new_inode(ip);
 	} else {
 		d_instantiate_new(dentry, ip);
 	}
@@ -1054,8 +1052,7 @@ static int jfs_symlink(struct inode *dip, struct dentry *dentry,
 	if (rc) {
 		free_ea_wmap(ip);
 		clear_nlink(ip);
-		unlock_new_inode(ip);
-		iput(ip);
+		discard_new_inode(ip);
 	} else {
 		d_instantiate_new(dentry, ip);
 	}
@@ -1441,8 +1438,7 @@ static int jfs_mknod(struct inode *dir, struct dentry *dentry,
 	if (rc) {
 		free_ea_wmap(ip);
 		clear_nlink(ip);
-		unlock_new_inode(ip);
-		iput(ip);
+		discard_new_inode(ip);
 	} else {
 		d_instantiate_new(dentry, ip);
 	}
-- 
cgit v1.2.3-55-g7522


From e950564b97fd0f541b02eb207685d0746f5ecf29 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi
Date: Tue, 24 Jul 2018 15:01:55 +0200
Subject: vfs: don't evict uninitialized inode

iput() ends up calling ->evict() on new inode, which is not yet initialized
by owning fs.  So use destroy_inode() instead.

Add to sb->s_inodes list only if inode is not in I_CREATING state (meaning
that it wasn't allocated with new_inode(), which already does the
insertion).

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 80ea09a002bf ("vfs: factor out inode_insert5()")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/inode.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/inode.c b/fs/inode.c
index 6cd2e7ba9f4d..e44a97584158 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1050,6 +1050,7 @@ struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
 {
 	struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval);
 	struct inode *old;
+	bool creating = inode->i_state & I_CREATING;
 
 again:
 	spin_lock(&inode_hash_lock);
@@ -1083,6 +1084,8 @@ again:
 	inode->i_state |= I_NEW;
 	hlist_add_head(&inode->i_hash, head);
 	spin_unlock(&inode->i_lock);
+	if (!creating)
+		inode_sb_list_add(inode);
 unlock:
 	spin_unlock(&inode_hash_lock);
 
@@ -1117,12 +1120,13 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
 	struct inode *inode = ilookup5(sb, hashval, test, data);
 
 	if (!inode) {
-		struct inode *new = new_inode(sb);
+		struct inode *new = alloc_inode(sb);
 
 		if (new) {
+			new->i_state = 0;
 			inode = inode_insert5(new, hashval, test, set, data);
 			if (unlikely(inode != new))
-				iput(new);
+				destroy_inode(new);
 		}
 	}
 	return inode;
-- 
cgit v1.2.3-55-g7522


From 5bef915104f32c9d0bb5df6e86a98e31cb524e9a Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Fri, 29 Jun 2018 19:36:57 -0400
Subject: new helper: inode_fake_hash()

open-coded in a quite a few places...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/hfs/inode.c     |  2 +-
 fs/jfs/jfs_imap.c  |  8 +-------
 fs/jfs/super.c     |  2 +-
 fs/xfs/xfs_iops.c  |  2 +-
 include/linux/fs.h | 11 +++++++++++
 5 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 2a16111d312f..a2dfa1b2a89c 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -541,7 +541,7 @@ static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
 	HFS_I(inode)->rsrc_inode = dir;
 	HFS_I(dir)->rsrc_inode = inode;
 	igrab(dir);
-	hlist_add_fake(&inode->i_hash);
+	inode_fake_hash(inode);
 	mark_inode_dirty(inode);
 	dont_mount(dentry);
 out:
diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index f36ef68905a7..93e8c590ff5c 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -491,13 +491,7 @@ struct inode *diReadSpecial(struct super_block *sb, ino_t inum, int secondary)
 	/* release the page */
 	release_metapage(mp);
 
-	/*
-	 * __mark_inode_dirty expects inodes to be hashed.  Since we don't
-	 * want special inodes in the fileset inode space, we make them
-	 * appear hashed, but do not put on any lists.  hlist_del()
-	 * will work fine and require no locking.
-	 */
-	hlist_add_fake(&ip->i_hash);
+	inode_fake_hash(ip);
 
 	return (ip);
 }
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 1b9264fd54b6..5403ece57dba 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -581,7 +581,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	inode->i_ino = 0;
 	inode->i_size = i_size_read(sb->s_bdev->bd_inode);
 	inode->i_mapping->a_ops = &jfs_metapage_aops;
-	hlist_add_fake(&inode->i_hash);
+	inode_fake_hash(inode);
 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 
 	sbi->direct_inode = inode;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 0fa29f39d658..3a75de777843 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1253,7 +1253,7 @@ xfs_setup_inode(
 
 	inode_sb_list_add(inode);
 	/* make the inode look hashed for the writeback code */
-	hlist_add_fake(&inode->i_hash);
+	inode_fake_hash(inode);
 
 	inode->i_uid    = xfs_uid_to_kuid(ip->i_d.di_uid);
 	inode->i_gid    = xfs_gid_to_kgid(ip->i_d.di_gid);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a42600565925..43941e230e2b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -684,6 +684,17 @@ static inline int inode_unhashed(struct inode *inode)
 	return hlist_unhashed(&inode->i_hash);
 }
 
+/*
+ * __mark_inode_dirty expects inodes to be hashed.  Since we don't
+ * want special inodes in the fileset inode space, we make them
+ * appear hashed, but do not put on any lists.  hlist_del()
+ * will work fine and require no locking.
+ */
+static inline void inode_fake_hash(struct inode *inode)
+{
+	hlist_add_fake(&inode->i_hash);
+}
+
 /*
  * inode->i_mutex nesting subclasses for the lock validator:
  *
-- 
cgit v1.2.3-55-g7522


From d8e78da8682028ad53d040339a2b9d6fb6092d63 Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Sat, 30 Jun 2018 03:15:49 -0400
Subject: adfs: don't put inodes into icache

We never look them up in there; inode_fake_hash() will make them appear
hashed for mark_inode_dirty() purposes.  And don't leave them around
until memory pressure kicks them out - we never look them up again.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/adfs/inode.c | 2 +-
 fs/adfs/super.c | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index c836c425ca94..e91028d4340a 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -287,7 +287,7 @@ adfs_iget(struct super_block *sb, struct object_info *obj)
 		ADFS_I(inode)->mmu_private = inode->i_size;
 	}
 
-	insert_inode_hash(inode);
+	inode_fake_hash(inode);
 
 out:
 	return inode;
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 71fa525d63a0..7e099a7a4eb1 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -291,6 +291,7 @@ static void destroy_inodecache(void)
 static const struct super_operations adfs_sops = {
 	.alloc_inode	= adfs_alloc_inode,
 	.destroy_inode	= adfs_destroy_inode,
+	.drop_inode	= generic_delete_inode,
 	.write_inode	= adfs_write_inode,
 	.put_super	= adfs_put_super,
 	.statfs		= adfs_statfs,
-- 
cgit v1.2.3-55-g7522


From c7b15a8657da7f8d11269c7cc3d8beef10d26b43 Mon Sep 17 00:00:00 2001
From: Al Viro
Date: Sat, 30 Jun 2018 14:32:04 -0400
Subject: jfs: don't bother with make_bad_inode() in ialloc()

We hit that when inumber allocation has failed.  In that case
the in-core inode is not hashed and since its ->i_nlink is 1
the only place where jfs checks is_bad_inode() won't be reached.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/jfs/jfs_inode.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/jfs/jfs_inode.c b/fs/jfs/jfs_inode.c
index 96732c24b054..4572b7cf183d 100644
--- a/fs/jfs/jfs_inode.c
+++ b/fs/jfs/jfs_inode.c
@@ -69,8 +69,6 @@ struct inode *ialloc(struct inode *parent, umode_t mode)
 	rc = diAlloc(parent, S_ISDIR(mode), inode);
 	if (rc) {
 		jfs_warn("ialloc: diAlloc returned %d!", rc);
-		if (rc == -EIO)
-			make_bad_inode(inode);
 		goto fail_put;
 	}
 
-- 
cgit v1.2.3-55-g7522