From: NeilBrown Sometimes smb2_create_link() needs to remove the target before creating the link. It uses ksmbd_vfs_kern_locked(), and is the only user of that interface. To match the new naming, that function is changed to ksmbd_vfs_kern_start_removing(), and related functions or flags are also renamed. The lock actually happens in ksmbd_vfs_path_lookup() and that is changed to use start_removing_noperm() - permission to perform lookup in the parent was already checked in vfs_path_parent_lookup(). Signed-off-by: NeilBrown --- fs/smb/server/smb2pdu.c | 6 +++--- fs/smb/server/vfs.c | 27 ++++++++++++--------------- fs/smb/server/vfs.h | 8 ++++---- 3 files changed, 19 insertions(+), 22 deletions(-) diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index f901ae18e68a..94454e8826b0 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -6092,8 +6092,8 @@ static int smb2_create_link(struct ksmbd_work *work, } ksmbd_debug(SMB, "target name is %s\n", target_name); - rc = ksmbd_vfs_kern_path_locked(work, link_name, LOOKUP_NO_SYMLINKS, - &path, 0); + rc = ksmbd_vfs_kern_path_start_removing(work, link_name, LOOKUP_NO_SYMLINKS, + &path, 0); if (rc) { if (rc != -ENOENT) goto out; @@ -6111,7 +6111,7 @@ static int smb2_create_link(struct ksmbd_work *work, ksmbd_debug(SMB, "link already exists\n"); goto out; } - ksmbd_vfs_kern_path_unlock(&path); + ksmbd_vfs_kern_path_end_removing(&path); } rc = ksmbd_vfs_link(work, target_name, link_name); if (rc) diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index 891ed2dc2b73..ea0a06b0ae44 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -69,7 +69,7 @@ int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child) static int ksmbd_vfs_path_lookup(struct ksmbd_share_config *share_conf, char *pathname, unsigned int flags, - struct path *path, bool do_lock) + struct path *path, bool for_remove) { struct qstr last; struct filename *filename __free(putname) = NULL; @@ -99,22 +99,20 @@ static int ksmbd_vfs_path_lookup(struct ksmbd_share_config *share_conf, return -ENOENT; } - if (do_lock) { + if (for_remove) { err = mnt_want_write(path->mnt); if (err) { path_put(path); return -ENOENT; } - inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT); - d = lookup_one_qstr_excl(&last, path->dentry, 0); + d = start_removing_noperm(path->dentry, &last); if (!IS_ERR(d)) { dput(path->dentry); path->dentry = d; return 0; } - inode_unlock(path->dentry->d_inode); mnt_drop_write(path->mnt); path_put(path); return -ENOENT; @@ -1207,7 +1205,7 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name, static int __ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath, unsigned int flags, - struct path *path, bool caseless, bool do_lock) + struct path *path, bool caseless, bool for_remove) { struct ksmbd_share_config *share_conf = work->tcon->share_conf; struct path parent_path; @@ -1215,7 +1213,7 @@ int __ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath, int err; retry: - err = ksmbd_vfs_path_lookup(share_conf, filepath, flags, path, do_lock); + err = ksmbd_vfs_path_lookup(share_conf, filepath, flags, path, for_remove); if (!err || !caseless) return err; @@ -1286,7 +1284,7 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath, } /** - * ksmbd_vfs_kern_path_locked() - lookup a file and get path info + * ksmbd_vfs_kern_path_start_remove() - lookup a file and get path info prior to removal * @work: work * @filepath: file path that is relative to share * @flags: lookup flags @@ -1298,20 +1296,19 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *filepath, * filesystem will have been gained. * Return: 0 on if file was found, otherwise error */ -int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *filepath, - unsigned int flags, - struct path *path, bool caseless) +int ksmbd_vfs_kern_path_start_removing(struct ksmbd_work *work, char *filepath, + unsigned int flags, + struct path *path, bool caseless) { return __ksmbd_vfs_kern_path(work, filepath, flags, path, caseless, true); } -void ksmbd_vfs_kern_path_unlock(const struct path *path) +void ksmbd_vfs_kern_path_end_removing(const struct path *path) { - /* While lock is still held, ->d_parent is safe */ - inode_unlock(d_inode(path->dentry->d_parent)); + end_removing(path->dentry); mnt_drop_write(path->mnt); - path_put(path); + mntput(path->mnt); } struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work, diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h index df6421b4590b..16ca29ee16e5 100644 --- a/fs/smb/server/vfs.h +++ b/fs/smb/server/vfs.h @@ -120,10 +120,10 @@ int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap, int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name, unsigned int flags, struct path *path, bool caseless); -int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name, - unsigned int flags, - struct path *path, bool caseless); -void ksmbd_vfs_kern_path_unlock(const struct path *path); +int ksmbd_vfs_kern_path_start_removing(struct ksmbd_work *work, char *name, + unsigned int flags, + struct path *path, bool caseless); +void ksmbd_vfs_kern_path_end_removing(const struct path *path); struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work, const char *name, unsigned int flags, -- 2.50.0.107.gf914562f5916.dirty