From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AFFF19F137; Wed, 12 Nov 2025 19:36:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762976192; cv=none; b=dEepY1xZ860dPWkk9iWqZodzs8Axn77WkWuMjymfgdWEYiZZaGlOMP6+tTFlZnZjoJAl7Hb83LB0tk+Ewh9Uc58K2uArw6Q8ABaUVkl0cVO7wXIvO3uzD5fp9GV8/KogqbAAjzpPHZE0YKmatCLmO4q52td/Qw5BKGX7VFEc84w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762976192; c=relaxed/simple; bh=p9hYXB8ZS+HmnDb4dTYqYkw5CEH2Z5Ksj0/1/HguPyw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=Z3kuvARgojsJ2l5bDEWudlE5/PHvNJrW0WRqrnzBVeHzHFwawNHikliVg4n/CeQD8RsIF7yaMU729e4CnPx4CNynnEFpkEDZMZlFJtdpNTCfzhA5MYqFtbdmDXYCn/RFTQHMTKSaAXXwQhNup/9p8w2usceTOd5l0OMcP4uS6QQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SXFkZ64S; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SXFkZ64S" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB12DC4CEF8; Wed, 12 Nov 2025 19:36:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762976192; bh=p9hYXB8ZS+HmnDb4dTYqYkw5CEH2Z5Ksj0/1/HguPyw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=SXFkZ64SoYG2qFTcvGq/xOnFtJG7gAz2v/4A3U4j0dETnvH67Jj1Wh4G8hPBlN7Re /AKGM+pmc6ktFBxd9lczLCVVWLXT7NC/3XF3iXGnY6rSze/D1YSjBB53d1LItSyxRy sPd1T0c2vSjKP1Dk16XHmijAQxaOyEOPU3wr1PTyVT4lTY6t4wCh5WwBGxQpxogQtq 5z61cFt03JFdG+/uqffbAYxtZc8sZOg+fNABhX97YTRYohRVBkoIeBTQ5hNYzK+RJW TqfEW9d7xODzA05mvybuk+pnQfhCqFEdSatO5HJEphazueIvBlTQV/C0lj5F5OV6oU DM/u3zH8SlSjQ== Message-ID: <78514a914be35c0ae84574c998f982bc73fdd4cf.camel@kernel.org> Subject: Re: [PATCH v5 10/14] VFS/ovl/smb: introduce start_renaming_dentry() From: Jeff Layton To: NeilBrown , Alexander Viro , Christian Brauner , Amir Goldstein Cc: Jan Kara , linux-fsdevel@vger.kernel.org, Chris Mason , David Sterba , David Howells , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Tyler Hicks , Miklos Szeredi , Chuck Lever , Olga Kornievskaia , Dai Ngo , Namjae Jeon , Steve French , Sergey Senozhatsky , Carlos Maiolino , John Johansen , Paul Moore , James Morris , "Serge E. Hallyn" , Stephen Smalley , Ondrej Mosnacek , Mateusz Guzik , Lorenzo Stoakes , Stefan Berger , "Darrick J. Wong" , linux-kernel@vger.kernel.org, netfs@lists.linux.dev, ecryptfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Date: Wed, 12 Nov 2025 14:36:27 -0500 In-Reply-To: <20251106005333.956321-11-neilb@ownmail.net> References: <20251106005333.956321-1-neilb@ownmail.net> <20251106005333.956321-11-neilb@ownmail.net> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn 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DfX/sn9XcfoVZIxMpCRE750zvJvcCUz9HojsrMQ1NFc7MFT1z3MOW2/RlzPcog7xvR5ENPH19ojRD CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.1 (3.58.1-1.fc43) Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2025-11-06 at 11:50 +1100, NeilBrown wrote: > From: NeilBrown >=20 > Several callers perform a rename on a dentry they already have, and only > require lookup for the target name. This includes smb/server and a few > different places in overlayfs. >=20 > start_renaming_dentry() performs the required lookup and takes the > required lock using lock_rename_child() >=20 > It is used in three places in overlayfs and in ksmbd_vfs_rename(). >=20 > In the ksmbd case, the parent of the source is not important - the > source must be renamed from wherever it is. So start_renaming_dentry() > allows rd->old_parent to be NULL and only checks it if it is non-NULL. > On success rd->old_parent will be the parent of old_dentry with an extra > reference taken. Other start_renaming function also now take the extra > reference and end_renaming() now drops this reference as well. >=20 > ovl_lookup_temp(), ovl_parent_lock(), and ovl_parent_unlock() are > all removed as they are no longer needed. >=20 > OVL_TEMPNAME_SIZE and ovl_tempname() are now declared in overlayfs.h so > that ovl_check_rename_whiteout() can access them. >=20 > ovl_copy_up_workdir() now always cleans up on error. >=20 > Reviewed-by: Namjae Jeon (for ksmbd part) > Reviewed-by: Amir Goldstein > Signed-off-by: NeilBrown > --- > fs/namei.c | 108 ++++++++++++++++++++++++++++++++++++--- > fs/overlayfs/copy_up.c | 54 +++++++++----------- > fs/overlayfs/dir.c | 19 +------ > fs/overlayfs/overlayfs.h | 8 +-- > fs/overlayfs/super.c | 22 ++++---- > fs/overlayfs/util.c | 11 ---- > fs/smb/server/vfs.c | 60 ++++------------------ > include/linux/namei.h | 2 + > 8 files changed, 150 insertions(+), 134 deletions(-) >=20 > diff --git a/fs/namei.c b/fs/namei.c > index bad6c9d540f9..4b740048df97 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -3669,7 +3669,7 @@ EXPORT_SYMBOL(unlock_rename); > =20 > /** > * __start_renaming - lookup and lock names for rename > - * @rd: rename data containing parent and flags, and > + * @rd: rename data containing parents and flags, and > * for receiving found dentries > * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, > * LOOKUP_NO_SYMLINKS etc). > @@ -3680,8 +3680,8 @@ EXPORT_SYMBOL(unlock_rename); > * rename. > * > * On success the found dentries are stored in @rd.old_dentry, > - * @rd.new_dentry. These references and the lock are dropped by > - * end_renaming(). > + * @rd.new_dentry and an extra ref is taken on @rd.old_parent. > + * These references and the lock are dropped by end_renaming(). > * > * The passed in qstrs must have the hash calculated, and no permission > * checking is performed. > @@ -3735,6 +3735,7 @@ __start_renaming(struct renamedata *rd, int lookup_= flags, > =20 > rd->old_dentry =3D d1; > rd->new_dentry =3D d2; > + dget(rd->old_parent); > return 0; > =20 > out_dput_d2: > @@ -3748,7 +3749,7 @@ __start_renaming(struct renamedata *rd, int lookup_= flags, > =20 > /** > * start_renaming - lookup and lock names for rename with permission che= cking > - * @rd: rename data containing parent and flags, and > + * @rd: rename data containing parents and flags, and > * for receiving found dentries > * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, > * LOOKUP_NO_SYMLINKS etc). > @@ -3759,8 +3760,8 @@ __start_renaming(struct renamedata *rd, int lookup_= flags, > * rename. > * > * On success the found dentries are stored in @rd.old_dentry, > - * @rd.new_dentry. These references and the lock are dropped by > - * end_renaming(). > + * @rd.new_dentry. Also the refcount on @rd->old_parent is increased. > + * These references and the lock are dropped by end_renaming(). > * > * The passed in qstrs need not have the hash calculated, and basic > * eXecute permission checking is performed against @rd.mnt_idmap. > @@ -3782,11 +3783,106 @@ int start_renaming(struct renamedata *rd, int lo= okup_flags, > } > EXPORT_SYMBOL(start_renaming); > =20 > +static int > +__start_renaming_dentry(struct renamedata *rd, int lookup_flags, > + struct dentry *old_dentry, struct qstr *new_last) > +{ > + struct dentry *trap; > + struct dentry *d2; > + int target_flags =3D LOOKUP_RENAME_TARGET | LOOKUP_CREATE; > + int err; > + > + if (rd->flags & RENAME_EXCHANGE) > + target_flags =3D 0; > + if (rd->flags & RENAME_NOREPLACE) > + target_flags |=3D LOOKUP_EXCL; > + > + /* Already have the dentry - need to be sure to lock the correct parent= */ > + trap =3D lock_rename_child(old_dentry, rd->new_parent); > + if (IS_ERR(trap)) > + return PTR_ERR(trap); > + if (d_unhashed(old_dentry) || > + (rd->old_parent && rd->old_parent !=3D old_dentry->d_parent)) { > + /* dentry was removed, or moved and explicit parent requested */ > + err =3D -EINVAL; > + goto out_unlock; > + } > + > + d2 =3D lookup_one_qstr_excl(new_last, rd->new_parent, > + lookup_flags | target_flags); > + err =3D PTR_ERR(d2); > + if (IS_ERR(d2)) > + goto out_unlock; > + > + if (old_dentry =3D=3D trap) { > + /* source is an ancestor of target */ > + err =3D -EINVAL; > + goto out_dput_d2; > + } > + > + if (d2 =3D=3D trap) { > + /* target is an ancestor of source */ > + if (rd->flags & RENAME_EXCHANGE) > + err =3D -EINVAL; > + else > + err =3D -ENOTEMPTY; > + goto out_dput_d2; > + } > + > + rd->old_dentry =3D dget(old_dentry); > + rd->new_dentry =3D d2; > + rd->old_parent =3D dget(old_dentry->d_parent); > + return 0; > + > +out_dput_d2: > + dput(d2); > +out_unlock: > + unlock_rename(old_dentry->d_parent, rd->new_parent); > + return err; > +} > + > +/** > + * start_renaming_dentry - lookup and lock name for rename with permissi= on checking > + * @rd: rename data containing parents and flags, and > + * for receiving found dentries > + * @lookup_flags: extra flags to pass to ->lookup (e.g. LOOKUP_REVAL, > + * LOOKUP_NO_SYMLINKS etc). > + * @old_dentry: dentry of name to move > + * @new_last: name of target in @rd.new_parent > + * > + * Look up target name and ensure locks are in place for > + * rename. > + * > + * On success the found dentry is stored in @rd.new_dentry and > + * @rd.old_parent is confirmed to be the parent of @old_dentry. If it > + * was originally %NULL, it is set. In either case a reference is taken > + * so that end_renaming() can have a stable reference to unlock. > + * > + * References and the lock can be dropped with end_renaming() > + * > + * The passed in qstr need not have the hash calculated, and basic > + * eXecute permission checking is performed against @rd.mnt_idmap. > + * > + * Returns: zero or an error. > + */ > +int start_renaming_dentry(struct renamedata *rd, int lookup_flags, > + struct dentry *old_dentry, struct qstr *new_last) > +{ > + int err; > + > + err =3D lookup_one_common(rd->mnt_idmap, new_last, rd->new_parent); > + if (err) > + return err; > + return __start_renaming_dentry(rd, lookup_flags, old_dentry, new_last); > +} > +EXPORT_SYMBOL(start_renaming_dentry); > + > void end_renaming(struct renamedata *rd) > { > unlock_rename(rd->old_parent, rd->new_parent); > dput(rd->old_dentry); > dput(rd->new_dentry); > + dput(rd->old_parent); > } > EXPORT_SYMBOL(end_renaming); > =20 > diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c > index e2bdac4317e7..9911a346b477 100644 > --- a/fs/overlayfs/copy_up.c > +++ b/fs/overlayfs/copy_up.c > @@ -523,8 +523,8 @@ static int ovl_create_index(struct dentry *dentry, co= nst struct ovl_fh *fh, > { > struct ovl_fs *ofs =3D OVL_FS(dentry->d_sb); > struct dentry *indexdir =3D ovl_indexdir(dentry->d_sb); > - struct dentry *index =3D NULL; > struct dentry *temp =3D NULL; > + struct renamedata rd =3D {}; > struct qstr name =3D { }; > int err; > =20 > @@ -556,17 +556,15 @@ static int ovl_create_index(struct dentry *dentry, = const struct ovl_fh *fh, > if (err) > goto out; > =20 > - err =3D ovl_parent_lock(indexdir, temp); > + rd.mnt_idmap =3D ovl_upper_mnt_idmap(ofs); > + rd.old_parent =3D indexdir; > + rd.new_parent =3D indexdir; > + err =3D start_renaming_dentry(&rd, 0, temp, &name); > if (err) > goto out; > - index =3D ovl_lookup_upper(ofs, name.name, indexdir, name.len); > - if (IS_ERR(index)) { > - err =3D PTR_ERR(index); > - } else { > - err =3D ovl_do_rename(ofs, indexdir, temp, indexdir, index, 0); > - dput(index); > - } > - ovl_parent_unlock(indexdir); > + > + err =3D ovl_do_rename_rd(&rd); > + end_renaming(&rd); > out: > if (err) > ovl_cleanup(ofs, indexdir, temp); > @@ -763,7 +761,8 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx= *c) > struct ovl_fs *ofs =3D OVL_FS(c->dentry->d_sb); > struct inode *inode; > struct path path =3D { .mnt =3D ovl_upper_mnt(ofs) }; > - struct dentry *temp, *upper, *trap; > + struct renamedata rd =3D {}; > + struct dentry *temp; > struct ovl_cu_creds cc; > int err; > struct ovl_cattr cattr =3D { > @@ -807,29 +806,24 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_c= tx *c) > * ovl_copy_up_data(), so lock workdir and destdir and make sure that > * temp wasn't moved before copy up completion or cleanup. > */ > - trap =3D lock_rename(c->workdir, c->destdir); > - if (trap || temp->d_parent !=3D c->workdir) { > - /* temp or workdir moved underneath us? abort without cleanup */ > - dput(temp); > + rd.mnt_idmap =3D ovl_upper_mnt_idmap(ofs); > + rd.old_parent =3D c->workdir; > + rd.new_parent =3D c->destdir; > + rd.flags =3D 0; > + err =3D start_renaming_dentry(&rd, 0, temp, > + &QSTR_LEN(c->destname.name, c->destname.len)); > + if (err) { > + /* temp or workdir moved underneath us? map to -EIO */ > err =3D -EIO; > - if (!IS_ERR(trap)) > - unlock_rename(c->workdir, c->destdir); > - goto out; > } > - > - err =3D ovl_copy_up_metadata(c, temp); > if (err) > - goto cleanup; > + goto cleanup_unlocked; > =20 > - upper =3D ovl_lookup_upper(ofs, c->destname.name, c->destdir, > - c->destname.len); > - err =3D PTR_ERR(upper); > - if (IS_ERR(upper)) > - goto cleanup; > + err =3D ovl_copy_up_metadata(c, temp); > + if (!err) > + err =3D ovl_do_rename_rd(&rd); > + end_renaming(&rd); > =20 > - err =3D ovl_do_rename(ofs, c->workdir, temp, c->destdir, upper, 0); > - unlock_rename(c->workdir, c->destdir); > - dput(upper); > if (err) > goto cleanup_unlocked; > =20 > @@ -850,8 +844,6 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx= *c) > =20 > return err; > =20 > -cleanup: > - unlock_rename(c->workdir, c->destdir); > cleanup_unlocked: > ovl_cleanup(ofs, c->workdir, temp); > dput(temp); > diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c > index cf6fc48459f3..6b2f88edb497 100644 > --- a/fs/overlayfs/dir.c > +++ b/fs/overlayfs/dir.c > @@ -57,8 +57,7 @@ int ovl_cleanup(struct ovl_fs *ofs, struct dentry *work= dir, > return 0; > } > =20 > -#define OVL_TEMPNAME_SIZE 20 > -static void ovl_tempname(char name[OVL_TEMPNAME_SIZE]) > +void ovl_tempname(char name[OVL_TEMPNAME_SIZE]) > { > static atomic_t temp_id =3D ATOMIC_INIT(0); > =20 > @@ -66,22 +65,6 @@ static void ovl_tempname(char name[OVL_TEMPNAME_SIZE]) > snprintf(name, OVL_TEMPNAME_SIZE, "#%x", atomic_inc_return(&temp_id)); > } > =20 > -struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdi= r) > -{ > - struct dentry *temp; > - char name[OVL_TEMPNAME_SIZE]; > - > - ovl_tempname(name); > - temp =3D ovl_lookup_upper(ofs, name, workdir, strlen(name)); > - if (!IS_ERR(temp) && temp->d_inode) { > - pr_err("workdir/%s already exists\n", name); > - dput(temp); > - temp =3D ERR_PTR(-EIO); > - } > - > - return temp; > -} > - > static struct dentry *ovl_start_creating_temp(struct ovl_fs *ofs, > struct dentry *workdir) > { > diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h > index 3cc85a893b5c..746bc4ad7b37 100644 > --- a/fs/overlayfs/overlayfs.h > +++ b/fs/overlayfs/overlayfs.h > @@ -447,11 +447,6 @@ static inline bool ovl_open_flags_need_copy_up(int f= lags) > } > =20 > /* util.c */ > -int ovl_parent_lock(struct dentry *parent, struct dentry *child); > -static inline void ovl_parent_unlock(struct dentry *parent) > -{ > - inode_unlock(parent->d_inode); > -} > int ovl_get_write_access(struct dentry *dentry); > void ovl_put_write_access(struct dentry *dentry); > void ovl_start_write(struct dentry *dentry); > @@ -888,7 +883,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, > struct dentry *parent, struct dentry *newdentry, > struct ovl_cattr *attr); > int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir, struct dentr= y *dentry); > -struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdi= r); > +#define OVL_TEMPNAME_SIZE 20 > +void ovl_tempname(char name[OVL_TEMPNAME_SIZE]); > struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdi= r, > struct ovl_cattr *attr); > =20 > diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c > index 6e0816c1147a..a721ef2b90e8 100644 > --- a/fs/overlayfs/super.c > +++ b/fs/overlayfs/super.c > @@ -566,9 +566,10 @@ static int ovl_check_rename_whiteout(struct ovl_fs *= ofs) > { > struct dentry *workdir =3D ofs->workdir; > struct dentry *temp; > - struct dentry *dest; > struct dentry *whiteout; > struct name_snapshot name; > + struct renamedata rd =3D {}; > + char name2[OVL_TEMPNAME_SIZE]; > int err; > =20 > temp =3D ovl_create_temp(ofs, workdir, OVL_CATTR(S_IFREG | 0)); > @@ -576,23 +577,21 @@ static int ovl_check_rename_whiteout(struct ovl_fs = *ofs) > if (IS_ERR(temp)) > return err; > =20 > - err =3D ovl_parent_lock(workdir, temp); > + rd.mnt_idmap =3D ovl_upper_mnt_idmap(ofs); > + rd.old_parent =3D workdir; > + rd.new_parent =3D workdir; > + rd.flags =3D RENAME_WHITEOUT; > + ovl_tempname(name2); > + err =3D start_renaming_dentry(&rd, 0, temp, &QSTR(name2)); > if (err) { > dput(temp); > return err; > } > - dest =3D ovl_lookup_temp(ofs, workdir); > - err =3D PTR_ERR(dest); > - if (IS_ERR(dest)) { > - dput(temp); > - ovl_parent_unlock(workdir); > - return err; > - } > =20 > /* Name is inline and stable - using snapshot as a copy helper */ > take_dentry_name_snapshot(&name, temp); > - err =3D ovl_do_rename(ofs, workdir, temp, workdir, dest, RENAME_WHITEOU= T); > - ovl_parent_unlock(workdir); > + err =3D ovl_do_rename_rd(&rd); > + end_renaming(&rd); > if (err) { > if (err =3D=3D -EINVAL) > err =3D 0; > @@ -616,7 +615,6 @@ static int ovl_check_rename_whiteout(struct ovl_fs *o= fs) > ovl_cleanup(ofs, workdir, temp); > release_dentry_name_snapshot(&name); > dput(temp); > - dput(dest); > =20 > return err; > } > diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c > index 2da1c035f716..fffc22859211 100644 > --- a/fs/overlayfs/util.c > +++ b/fs/overlayfs/util.c > @@ -1548,14 +1548,3 @@ void ovl_copyattr(struct inode *inode) > i_size_write(inode, i_size_read(realinode)); > spin_unlock(&inode->i_lock); > } > - > -int ovl_parent_lock(struct dentry *parent, struct dentry *child) > -{ > - inode_lock_nested(parent->d_inode, I_MUTEX_PARENT); > - if (!child || > - (!d_unhashed(child) && child->d_parent =3D=3D parent)) > - return 0; > - > - inode_unlock(parent->d_inode); > - return -EINVAL; > -} > diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c > index 7c4ddc43ab39..f54b5b0aaba2 100644 > --- a/fs/smb/server/vfs.c > +++ b/fs/smb/server/vfs.c > @@ -663,7 +663,6 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const cha= r *oldname, > int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_pat= h, > char *newname, int flags) > { > - struct dentry *old_parent, *new_dentry, *trap; > struct dentry *old_child =3D old_path->dentry; > struct path new_path; > struct qstr new_last; > @@ -673,7 +672,6 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const s= truct path *old_path, > struct ksmbd_file *parent_fp; > int new_type; > int err, lookup_flags =3D LOOKUP_NO_SYMLINKS; > - int target_lookup_flags =3D LOOKUP_RENAME_TARGET | LOOKUP_CREATE; > =20 > if (ksmbd_override_fsids(work)) > return -ENOMEM; > @@ -684,14 +682,6 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const = struct path *old_path, > goto revert_fsids; > } > =20 > - /* > - * explicitly handle file overwrite case, for compatibility with > - * filesystems that may not support rename flags (e.g: fuse) > - */ > - if (flags & RENAME_NOREPLACE) > - target_lookup_flags |=3D LOOKUP_EXCL; > - flags &=3D ~(RENAME_NOREPLACE); > - > retry: > err =3D vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH, > &new_path, &new_last, &new_type, > @@ -708,17 +698,14 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const= struct path *old_path, > if (err) > goto out2; > =20 > - trap =3D lock_rename_child(old_child, new_path.dentry); > - if (IS_ERR(trap)) { > - err =3D PTR_ERR(trap); > + rd.mnt_idmap =3D mnt_idmap(old_path->mnt); > + rd.old_parent =3D NULL; > + rd.new_parent =3D new_path.dentry; > + rd.flags =3D flags; > + rd.delegated_inode =3D NULL, > + err =3D start_renaming_dentry(&rd, lookup_flags, old_child, &new_last); > + if (err) > goto out_drop_write; > - } > - > - old_parent =3D dget(old_child->d_parent); > - if (d_unhashed(old_child)) { > - err =3D -EINVAL; > - goto out3; > - } > =20 > parent_fp =3D ksmbd_lookup_fd_inode(old_child->d_parent); > if (parent_fp) { > @@ -731,44 +718,17 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const= struct path *old_path, > ksmbd_fd_put(work, parent_fp); > } > =20 > - new_dentry =3D lookup_one_qstr_excl(&new_last, new_path.dentry, > - lookup_flags | target_lookup_flags); > - if (IS_ERR(new_dentry)) { > - err =3D PTR_ERR(new_dentry); > - goto out3; > - } > - > - if (d_is_symlink(new_dentry)) { > + if (d_is_symlink(rd.new_dentry)) { > err =3D -EACCES; > - goto out4; > - } > - > - if (old_child =3D=3D trap) { > - err =3D -EINVAL; > - goto out4; > - } > - > - if (new_dentry =3D=3D trap) { > - err =3D -ENOTEMPTY; > - goto out4; > + goto out3; > } > =20 > - rd.mnt_idmap =3D mnt_idmap(old_path->mnt), > - rd.old_parent =3D old_parent, > - rd.old_dentry =3D old_child, > - rd.new_parent =3D new_path.dentry, > - rd.new_dentry =3D new_dentry, > - rd.flags =3D flags, > - rd.delegated_inode =3D NULL, > err =3D vfs_rename(&rd); > if (err) > ksmbd_debug(VFS, "vfs_rename failed err %d\n", err); > =20 > -out4: > - dput(new_dentry); > out3: > - dput(old_parent); > - unlock_rename(old_parent, new_path.dentry); > + end_renaming(&rd); > out_drop_write: > mnt_drop_write(old_path->mnt); > out2: > diff --git a/include/linux/namei.h b/include/linux/namei.h > index 7fdd9fdcbd2b..c47713e9867c 100644 > --- a/include/linux/namei.h > +++ b/include/linux/namei.h > @@ -159,6 +159,8 @@ extern struct dentry *lock_rename_child(struct dentry= *, struct dentry *); > extern void unlock_rename(struct dentry *, struct dentry *); > int start_renaming(struct renamedata *rd, int lookup_flags, > struct qstr *old_last, struct qstr *new_last); > +int start_renaming_dentry(struct renamedata *rd, int lookup_flags, > + struct dentry *old_dentry, struct qstr *new_last); > void end_renaming(struct renamedata *rd); > =20 > /** Reviewed-by: Jeff Layton