milos-linux/fs/kernfs
NeilBrown fa6fe07d15
VFS: rename lookup_one_len family to lookup_noperm and remove permission check
The lookup_one_len family of functions is (now) only used internally by
a filesystem on itself either
- in a context where permission checking is irrelevant such as by a
  virtual filesystem populating itself, or xfs accessing its ORPHANAGE
  or dquota accessing the quota file; or
- in a context where a permission check (MAY_EXEC on the parent) has just
  been performed such as a network filesystem finding in "silly-rename"
  file in the same directory.  This is also the context after the
  _parentat() functions where currently lookup_one_qstr_excl() is used.

So the permission check is pointless.

The name "one_len" is unhelpful in understanding the purpose of these
functions and should be changed.  Most of the callers pass the len as
"strlen()" so using a qstr and QSTR() can simplify the code.

This patch renames these functions (include lookup_positive_unlocked()
which is part of the family despite the name) to have a name based on
"lookup_noperm".  They are changed to receive a 'struct qstr' instead
of separate name and len.  In a few cases the use of QSTR() results in a
new call to strlen().

try_lookup_noperm() takes a pointer to a qstr instead of the whole
qstr.  This is consistent with d_hash_and_lookup() (which is nearly
identical) and useful for lookup_noperm_unlocked().

The new lookup_noperm_common() doesn't take a qstr yet.  That will be
tidied up in a subsequent patch.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://lore.kernel.org/r/20250319031545.2999807-5-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-04-08 11:24:36 +02:00
..
dir.c Driver core updates for 6.15-rc1 2025-04-01 11:02:03 -07:00
file.c kernfs: Use RCU to access kernfs_node::name. 2025-02-15 17:46:32 +01:00
inode.c vfs-6.7.ctime 2023-10-30 09:47:13 -10:00
Kconfig
kernfs-internal.h kernfs: Use RCU to access kernfs_node::name. 2025-02-15 17:46:32 +01:00
Makefile
mount.c VFS: rename lookup_one_len family to lookup_noperm and remove permission check 2025-04-08 11:24:36 +02:00
symlink.c kernfs: Use RCU to access kernfs_node::name. 2025-02-15 17:46:32 +01:00