From: NeilBrown <neil@xxxxxxxxxx>
kern_path_locked() is now only used to prepare for removing an object
from the filesystem (and that is the only credible reason for wanting a
positive locked dentry). Thus it corresponds to kern_path_create() and
so should have a corresponding name.
Unfortunately the name "kern_path_create" is somewhat misleading as it
doesn't actually create anything. The recently added
simple_start_creating() provides a better pattern I believe. The
"start" can be matched with "end" to bracket the creating or removing.
So this patch changes names:
kern_path_locked -> start_removing_path
kern_path_create -> start_creating_path
user_path_create -> start_creating_user_path
user_path_locked_at -> start_removing_user_path_at
done_path_create -> end_creating_path
and also introduces end_removing_path() which is identical to
end_creating_path().
__start_removing_path (which was __kern_path_locked) is enhanced to
call mnt_want_write() for consistency with the start_creating_path().
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
Documentation/filesystems/porting.rst | 12 ++++
arch/powerpc/platforms/cell/spufs/syscalls.c | 4 +-
drivers/base/devtmpfs.c | 22 +++-----
fs/bcachefs/fs-ioctl.c | 10 ++--
fs/init.c | 17 +++---
fs/namei.c | 59 ++++++++++++--------
fs/ocfs2/refcounttree.c | 4 +-
fs/smb/server/vfs.c | 8 +--
include/linux/namei.h | 14 +++--
kernel/bpf/inode.c | 4 +-
net/unix/af_unix.c | 6 +-
11 files changed, 93 insertions(+), 67 deletions(-)
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 85f590254f07..e0494860be6b 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1285,3 +1285,15 @@ rather than a VMA, as the VMA at this stage is not yet valid.
The vm_area_desc provides the minimum required information for a filesystem
to initialise state upon memory mapping of a file-backed region, and output
parameters for the file system to set this state.
+
+---
+
+**mandatory**
+
+Several functions are renamed:
+
+- kern_path_locked -> start_removing_path
+- kern_path_create -> start_creating_path
+- user_path_create -> start_creating_user_path
+- user_path_locked_at -> start_removing_user_path_at
+- done_path_create -> end_creating_path
diff --git a/arch/powerpc/platforms/cell/spufs/syscalls.c b/arch/powerpc/platforms/cell/spufs/syscalls.c
index 157e046e6e93..ea4ba1b6ce6a 100644
--- a/arch/powerpc/platforms/cell/spufs/syscalls.c
+++ b/arch/powerpc/platforms/cell/spufs/syscalls.c
@@ -67,11 +67,11 @@ static long do_spu_create(const char __user *pathname, unsigned int flags,
struct dentry *dentry;
int ret;
- dentry = user_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
+ dentry = start_creating_user_path(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
ret = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
ret = spufs_create(&path, dentry, flags, mode, neighbor);
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
}
return ret;
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 31bfb3194b4c..9d4e46ad8352 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -176,7 +176,7 @@ static int dev_mkdir(const char *name, umode_t mode)
struct dentry *dentry;
struct path path;
- dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
+ dentry = start_creating_path(AT_FDCWD, name, &path, LOOKUP_DIRECTORY);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -184,7 +184,7 @@ static int dev_mkdir(const char *name, umode_t mode)
if (!IS_ERR(dentry))
/* mark as kernel-created inode */
d_inode(dentry)->i_private = &thread;
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return PTR_ERR_OR_ZERO(dentry);
}
@@ -222,10 +222,10 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
struct path path;
int err;
- dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
+ dentry = start_creating_path(AT_FDCWD, nodename, &path, 0);
if (dentry == ERR_PTR(-ENOENT)) {
create_path(nodename);
- dentry = kern_path_create(AT_FDCWD, nodename, &path, 0);
+ dentry = start_creating_path(AT_FDCWD, nodename, &path, 0);
}
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -246,7 +246,7 @@ static int handle_create(const char *nodename, umode_t mode, kuid_t uid,
/* mark as kernel-created inode */
d_inode(dentry)->i_private = &thread;
}
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return err;
}
@@ -256,7 +256,7 @@ static int dev_rmdir(const char *name)
struct dentry *dentry;
int err;
- dentry = kern_path_locked(name, &parent);
+ dentry = start_removing_path(name, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
if (d_inode(dentry)->i_private == &thread)
@@ -265,9 +265,7 @@ static int dev_rmdir(const char *name)
else
err = -EPERM;
- dput(dentry);
- inode_unlock(d_inode(parent.dentry));
- path_put(&parent);
+ end_removing_path(&parent, dentry);
return err;
}
@@ -325,7 +323,7 @@ static int handle_remove(const char *nodename, struct device *dev)
int deleted = 0;
int err = 0;
- dentry = kern_path_locked(nodename, &parent);
+ dentry = start_removing_path(nodename, &parent);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -349,10 +347,8 @@ static int handle_remove(const char *nodename, struct device *dev)
if (!err || err == -ENOENT)
deleted = 1;
}
- dput(dentry);
- inode_unlock(d_inode(parent.dentry));
+ end_removing_path(&parent, dentry);
- path_put(&parent);
if (deleted && strchr(nodename, '/'))
delete_path(nodename);
return err;
diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
index 4e72e654da96..43510da5e734 100644
--- a/fs/bcachefs/fs-ioctl.c
+++ b/fs/bcachefs/fs-ioctl.c
@@ -255,7 +255,7 @@ static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
snapshot_src = inode_inum(to_bch_ei(src_path.dentry->d_inode));
}
- dst_dentry = user_path_create(arg.dirfd,
+ dst_dentry = start_creating_user_path(arg.dirfd,
(const char __user *)(unsigned long)arg.dst_ptr,
&dst_path, lookup_flags);
error = PTR_ERR_OR_ZERO(dst_dentry);
@@ -314,7 +314,7 @@ static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
d_instantiate(dst_dentry, &inode->v);
fsnotify_mkdir(dir, dst_dentry);
err3:
- done_path_create(&dst_path, dst_dentry);
+ end_creating_path(&dst_path, dst_dentry);
err2:
if (arg.src_ptr)
path_put(&src_path);
@@ -334,7 +334,7 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
if (arg.flags)
return -EINVAL;
- victim = user_path_locked_at(arg.dirfd, name, &path);
+ victim = start_removing_user_path_at(arg.dirfd, name, &path);
if (IS_ERR(victim))
return PTR_ERR(victim);
@@ -351,9 +351,7 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
d_invalidate(victim);
}
err:
- inode_unlock(dir);
- dput(victim);
- path_put(&path);
+ end_removing_path(&path, victim);
return ret;
}
diff --git a/fs/init.c b/fs/init.c
index eef5124885e3..07f592ccdba8 100644
--- a/fs/init.c
+++ b/fs/init.c
@@ -149,7 +149,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
else if (!(S_ISBLK(mode) || S_ISCHR(mode)))
return -EINVAL;
- dentry = kern_path_create(AT_FDCWD, filename, &path, 0);
+ dentry = start_creating_path(AT_FDCWD, filename, &path, 0);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -158,7 +158,7 @@ int __init init_mknod(const char *filename, umode_t mode, unsigned int dev)
if (!error)
error = vfs_mknod(mnt_idmap(path.mnt), path.dentry->d_inode,
dentry, mode, new_decode_dev(dev));
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return error;
}
@@ -173,7 +173,7 @@ int __init init_link(const char *oldname, const char *newname)
if (error)
return error;
- new_dentry = kern_path_create(AT_FDCWD, newname, &new_path, 0);
+ new_dentry = start_creating_path(AT_FDCWD, newname, &new_path, 0);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto out;
@@ -191,7 +191,7 @@ int __init init_link(const char *oldname, const char *newname)
error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
new_dentry, NULL);
out_dput:
- done_path_create(&new_path, new_dentry);
+ end_creating_path(&new_path, new_dentry);
out:
path_put(&old_path);
return error;
@@ -203,14 +203,14 @@ int __init init_symlink(const char *oldname, const char *newname)
struct path path;
int error;
- dentry = kern_path_create(AT_FDCWD, newname, &path, 0);
+ dentry = start_creating_path(AT_FDCWD, newname, &path, 0);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
error = security_path_symlink(&path, dentry, oldname);
if (!error)
error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
dentry, oldname);
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return error;
}
@@ -225,7 +225,8 @@ int __init init_mkdir(const char *pathname, umode_t mode)
struct path path;
int error;
- dentry = kern_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
+ dentry = start_creating_path(AT_FDCWD, pathname, &path,
+ LOOKUP_DIRECTORY);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
mode = mode_strip_umask(d_inode(path.dentry), mode);
@@ -236,7 +237,7 @@ int __init init_mkdir(const char *pathname, umode_t mode)
if (IS_ERR(dentry))
error = PTR_ERR(dentry);
}
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return error;
}
diff --git a/fs/namei.c b/fs/namei.c
index 4017bc8641d3..5ceb971632fe 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2758,7 +2758,8 @@ static int filename_parentat(int dfd, struct filename *name,
}
/* does lookup, returns the object with parent locked */
-static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct path *path)
+static struct dentry *__start_removing_path(int dfd, struct filename *name,
+ struct path *path)
{
struct path parent_path __free(path_put) = {};
struct dentry *d;
@@ -2770,15 +2771,26 @@ static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct
return ERR_PTR(error);
if (unlikely(type != LAST_NORM))
return ERR_PTR(-EINVAL);
+ /* don't fail immediately if it's r/o, at least try to report other errors */
+ error = mnt_want_write(path->mnt);
inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
d = lookup_one_qstr_excl(&last, parent_path.dentry, 0);
- if (IS_ERR(d)) {
- inode_unlock(parent_path.dentry->d_inode);
- return d;
- }
+ if (IS_ERR(d))
+ goto unlock;
+ if (error)
+ goto fail;
path->dentry = no_free_ptr(parent_path.dentry);
path->mnt = no_free_ptr(parent_path.mnt);
return d;
+
+fail:
+ dput(d);
+ d = ERR_PTR(error);
+unlock:
+ inode_unlock(parent_path.dentry->d_inode);
+ if (!error)
+ mnt_drop_write(path->mnt);
+ return d;
}
/**
@@ -2816,24 +2828,26 @@ struct dentry *kern_path_parent(const char *name, struct path *path)
return d;
}
-struct dentry *kern_path_locked(const char *name, struct path *path)
+struct dentry *start_removing_path(const char *name, struct path *path)
{
struct filename *filename = getname_kernel(name);
- struct dentry *res = __kern_path_locked(AT_FDCWD, filename, path);
+ struct dentry *res = __start_removing_path(AT_FDCWD, filename, path);
putname(filename);
return res;
}
-struct dentry *user_path_locked_at(int dfd, const char __user *name, struct path *path)
+struct dentry *start_removing_user_path_at(int dfd,
+ const char __user *name,
+ struct path *path)
{
struct filename *filename = getname(name);
- struct dentry *res = __kern_path_locked(dfd, filename, path);
+ struct dentry *res = __start_removing_path(dfd, filename, path);
putname(filename);
return res;
}
-EXPORT_SYMBOL(user_path_locked_at);
+EXPORT_SYMBOL(start_removing_user_path_at);
int kern_path(const char *name, unsigned int flags, struct path *path)
{
@@ -4223,8 +4237,8 @@ static struct dentry *filename_create(int dfd, struct filename *name,
return dentry;
}
-struct dentry *kern_path_create(int dfd, const char *pathname,
- struct path *path, unsigned int lookup_flags)
+struct dentry *start_creating_path(int dfd, const char *pathname,
+ struct path *path, unsigned int lookup_flags)
{
struct filename *filename = getname_kernel(pathname);
struct dentry *res = filename_create(dfd, filename, path, lookup_flags);
@@ -4232,9 +4246,9 @@ struct dentry *kern_path_create(int dfd, const char *pathname,
putname(filename);
return res;
}
-EXPORT_SYMBOL(kern_path_create);
+EXPORT_SYMBOL(start_creating_path);
-void done_path_create(struct path *path, struct dentry *dentry)
+void end_creating_path(struct path *path, struct dentry *dentry)
{
if (!IS_ERR(dentry))
dput(dentry);
@@ -4242,10 +4256,11 @@ void done_path_create(struct path *path, struct dentry *dentry)
mnt_drop_write(path->mnt);
path_put(path);
}
-EXPORT_SYMBOL(done_path_create);
+EXPORT_SYMBOL(end_creating_path);
-inline struct dentry *user_path_create(int dfd, const char __user *pathname,
- struct path *path, unsigned int lookup_flags)
+inline struct dentry *start_creating_user_path(
+ int dfd, const char __user *pathname,
+ struct path *path, unsigned int lookup_flags)
{
struct filename *filename = getname(pathname);
struct dentry *res = filename_create(dfd, filename, path, lookup_flags);
@@ -4253,7 +4268,7 @@ inline struct dentry *user_path_create(int dfd, const char __user *pathname,
putname(filename);
return res;
}
-EXPORT_SYMBOL(user_path_create);
+EXPORT_SYMBOL(start_creating_user_path);
/**
* vfs_mknod - create device node or file
@@ -4361,7 +4376,7 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode,
break;
}
out2:
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
@@ -4465,7 +4480,7 @@ int do_mkdirat(int dfd, struct filename *name, umode_t mode)
if (IS_ERR(dentry))
error = PTR_ERR(dentry);
}
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
@@ -4819,7 +4834,7 @@ int do_symlinkat(struct filename *from, int newdfd, struct filename *to)
if (!error)
error = vfs_symlink(mnt_idmap(path.mnt), path.dentry->d_inode,
dentry, from->name);
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
@@ -4988,7 +5003,7 @@ int do_linkat(int olddfd, struct filename *old, int newdfd,
error = vfs_link(old_path.dentry, idmap, new_path.dentry->d_inode,
new_dentry, &delegated_inode);
out_dput:
- done_path_create(&new_path, new_dentry);
+ end_creating_path(&new_path, new_dentry);
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);
if (!error) {
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 8f732742b26e..267b50e8e42e 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -4418,7 +4418,7 @@ int ocfs2_reflink_ioctl(struct inode *inode,
return error;
}
- new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0);
+ new_dentry = start_creating_user_path(AT_FDCWD, newname, &new_path, 0);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry)) {
mlog_errno(error);
@@ -4435,7 +4435,7 @@ int ocfs2_reflink_ioctl(struct inode *inode,
d_inode(new_path.dentry),
new_dentry, preserve);
out_dput:
- done_path_create(&new_path, new_dentry);
+ end_creating_path(&new_path, new_dentry);
out:
path_put(&old_path);
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 07739055ac9f..1cfa688904b2 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -196,7 +196,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
pr_err("File(%s): creation failed (err:%d)\n", name, err);
}
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return err;
}
@@ -237,7 +237,7 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
if (!err && dentry != d)
ksmbd_vfs_inherit_owner(work, d_inode(path.dentry), d_inode(dentry));
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
if (err)
pr_err("mkdir(%s): creation failed (err:%d)\n", name, err);
return err;
@@ -669,7 +669,7 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
ksmbd_debug(VFS, "vfs_link failed err %d\n", err);
out3:
- done_path_create(&newpath, dentry);
+ end_creating_path(&newpath, dentry);
out2:
path_put(&oldpath);
out1:
@@ -1325,7 +1325,7 @@ struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
if (!abs_name)
return ERR_PTR(-ENOMEM);
- dent = kern_path_create(AT_FDCWD, abs_name, path, flags);
+ dent = start_creating_path(AT_FDCWD, abs_name, path, flags);
kfree(abs_name);
return dent;
}
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 1d5038c21c20..a7800ef04e76 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -59,11 +59,15 @@ struct dentry *lookup_one_qstr_excl(const struct qstr *name,
extern int kern_path(const char *, unsigned, struct path *);
struct dentry *kern_path_parent(const char *name, struct path *parent);
-extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
-extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
-extern void done_path_create(struct path *, struct dentry *);
-extern struct dentry *kern_path_locked(const char *, struct path *);
-extern struct dentry *user_path_locked_at(int , const char __user *, struct path *);
+extern struct dentry *start_creating_path(int, const char *, struct path *, unsigned int);
+extern struct dentry *start_creating_user_path(int, const char __user *, struct path *, unsigned int);
+extern void end_creating_path(struct path *, struct dentry *);
+extern struct dentry *start_removing_path(const char *, struct path *);
+extern struct dentry *start_removing_user_path_at(int , const char __user *, struct path *);
+static inline void end_removing_path(struct path *path , struct dentry *dentry)
+{
+ end_creating_path(path, dentry);
+}
int vfs_path_parent_lookup(struct filename *filename, unsigned int flags,
struct path *parent, struct qstr *last, int *type,
const struct path *root);
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 5c2e96b19392..fadf3817a9c5 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -442,7 +442,7 @@ static int bpf_obj_do_pin(int path_fd, const char __user *pathname, void *raw,
umode_t mode;
int ret;
- dentry = user_path_create(path_fd, pathname, &path, 0);
+ dentry = start_creating_user_path(path_fd, pathname, &path, 0);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -471,7 +471,7 @@ static int bpf_obj_do_pin(int path_fd, const char __user *pathname, void *raw,
ret = -EPERM;
}
out:
- done_path_create(&path, dentry);
+ end_creating_path(&path, dentry);
return ret;
}
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 6d7c110814ff..768098dec231 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1387,7 +1387,7 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
* Get the parent directory, calculate the hash for last
* component.
*/
- dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0);
+ dentry = start_creating_path(AT_FDCWD, addr->name->sun_path, &parent, 0);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
@@ -1417,7 +1417,7 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
unix_table_double_unlock(net, old_hash, new_hash);
unix_insert_bsd_socket(sk);
mutex_unlock(&u->bindlock);
- done_path_create(&parent, dentry);
+ end_creating_path(&parent, dentry);
return 0;
out_unlock:
@@ -1427,7 +1427,7 @@ static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
/* failed after successful mknod? unlink what we'd created... */
vfs_unlink(idmap, d_inode(parent.dentry), dentry, NULL);
out_path:
- done_path_create(&parent, dentry);
+ end_creating_path(&parent, dentry);
out:
unix_release_addr(addr);
return err == -EEXIST ? -EADDRINUSE : err;
--
2.50.0.107.gf914562f5916.dirty
