Merge tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs async dir updates from Christian Brauner:
 "This contains cleanups that fell out of the work from async directory
  handling:

   - Change kern_path_locked() and user_path_locked_at() to never return
     a negative dentry. This simplifies the usability of these helpers
     in various places

   - Drop d_exact_alias() from the remaining place in NFS where it is
     still used. This also allows us to drop the d_exact_alias() helper
     completely

   - Drop an unnecessary call to fh_update() from nfsd_create_locked()

   - Change i_op->mkdir() to return a struct dentry

     Change vfs_mkdir() to return a dentry provided by the filesystems
     which is hashed and positive. This allows us to reduce the number
     of cases where the resulting dentry is not positive to very few
     cases. The code in these places becomes simpler and easier to
     understand.

   - Repack DENTRY_* and LOOKUP_* flags"

* tag 'vfs-6.15-rc1.async.dir' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  doc: fix inline emphasis warning
  VFS: Change vfs_mkdir() to return the dentry.
  nfs: change mkdir inode_operation to return alternate dentry if needed.
  fuse: return correct dentry for ->mkdir
  ceph: return the correct dentry on mkdir
  hostfs: store inode in dentry after mkdir if possible.
  Change inode_operations.mkdir to return struct dentry *
  nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked()
  nfs/vfs: discard d_exact_alias()
  VFS: add common error checks to lookup_one_qstr_excl()
  VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry
  VFS: repack LOOKUP_ bit flags.
  VFS: repack DENTRY_ flags.

1 files changed, 32 insertions, 18 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 3805f9b06c9d..fa8f1141ea74 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -781,9 +781,9 @@ no_open:
 /*
  * Code shared between mknod, mkdir, symlink and link
  */
-static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
-			    struct fuse_args *args, struct inode *dir,
-			    struct dentry *entry, umode_t mode)
+static struct dentry *create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
+				       struct fuse_args *args, struct inode *dir,
+				       struct dentry *entry, umode_t mode)
 {
 	struct fuse_entry_out outarg;
 	struct inode *inode;
@@ -792,11 +792,11 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
 	struct fuse_forget_link *forget;
 
 	if (fuse_is_bad(dir))
-		return -EIO;
+		return ERR_PTR(-EIO);
 
 	forget = fuse_alloc_forget();
 	if (!forget)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	memset(&outarg, 0, sizeof(outarg));
 	args->nodeid = get_node_id(dir);
@@ -826,29 +826,43 @@ static int create_new_entry(struct mnt_idmap *idmap, struct fuse_mount *fm,
 			  &outarg.attr, ATTR_TIMEOUT(&outarg), 0, 0);
 	if (!inode) {
 		fuse_queue_forget(fm->fc, forget, outarg.nodeid, 1);
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	}
 	kfree(forget);
 
 	d_drop(entry);
 	d = d_splice_alias(inode, entry);
 	if (IS_ERR(d))
-		return PTR_ERR(d);
+		return d;
 
-	if (d) {
+	if (d)
 		fuse_change_entry_timeout(d, &outarg);
-		dput(d);
-	} else {
+	else
 		fuse_change_entry_timeout(entry, &outarg);
-	}
 	fuse_dir_changed(dir);
-	return 0;
+	return d;
 
  out_put_forget_req:
 	if (err == -EEXIST)
 		fuse_invalidate_entry(entry);
 	kfree(forget);
-	return err;
+	return ERR_PTR(err);
+}
+
+static int create_new_nondir(struct mnt_idmap *idmap, struct fuse_mount *fm,
+			     struct fuse_args *args, struct inode *dir,
+			     struct dentry *entry, umode_t mode)
+{
+	/*
+	 * Note that when creating anything other than a directory we
+	 * can be sure create_new_entry() will NOT return an alternate
+	 * dentry as d_splice_alias() only returns an alternate dentry
+	 * for directories.  So we don't need to check for that case
+	 * when passing back the result.
+	 */
+	WARN_ON_ONCE(S_ISDIR(mode));
+
+	return PTR_ERR(create_new_entry(idmap, fm, args, dir, entry, mode));
 }
 
 static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
@@ -871,7 +885,7 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	args.in_args[0].value = &inarg;
 	args.in_args[1].size = entry->d_name.len + 1;
 	args.in_args[1].value = entry->d_name.name;
-	return create_new_entry(idmap, fm, &args, dir, entry, mode);
+	return create_new_nondir(idmap, fm, &args, dir, entry, mode);
 }
 
 static int fuse_create(struct mnt_idmap *idmap, struct inode *dir,
@@ -898,8 +912,8 @@ static int fuse_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 	return err;
 }
 
-static int fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir,
-		      struct dentry *entry, umode_t mode)
+static struct dentry *fuse_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				 struct dentry *entry, umode_t mode)
 {
 	struct fuse_mkdir_in inarg;
 	struct fuse_mount *fm = get_fuse_mount(dir);
@@ -934,7 +948,7 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	args.in_args[1].value = entry->d_name.name;
 	args.in_args[2].size = len;
 	args.in_args[2].value = link;
-	return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
+	return create_new_nondir(idmap, fm, &args, dir, entry, S_IFLNK);
 }
 
 void fuse_flush_time_update(struct inode *inode)
@@ -1131,7 +1145,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
 	args.in_args[0].value = &inarg;
 	args.in_args[1].size = newent->d_name.len + 1;
 	args.in_args[1].value = newent->d_name.name;
-	err = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
+	err = create_new_nondir(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
 	if (!err)
 		fuse_update_ctime_in_cache(inode);
 	else if (err == -EINTR)