Merge tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE
     permission checks during path lookup and adds the
     IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid
     expensive permission work.

   - Hide dentry_cache behind runtime const machinery.

   - Add German Maglione as virtiofs co-maintainer.

  Cleanups:

   - Tidy up and inline step_into() and walk_component() for improved
     code generation.

   - Re-enable IOCB_NOWAIT writes to files. This refactors file
     timestamp update logic, fixing a layering bypass in btrfs when
     updating timestamps on device files and improving FMODE_NOCMTIME
     handling in VFS now that nfsd started using it.

   - Path lookup optimizations extracting slowpaths into dedicated
     routines and adding branch prediction hints for mntput_no_expire(),
     fd_install(), lookup_slow(), and various other hot paths.

   - Enable clang's -fms-extensions flag, requiring a JFS rename to
     avoid conflicts.

   - Remove spurious exports in fs/file_attr.c.

   - Stop duplicating union pipe_index declaration. This depends on the
     shared kbuild branch that brings in -fms-extensions support which
     is merged into this branch.

   - Use MD5 library instead of crypto_shash in ecryptfs.

   - Use largest_zero_folio() in iomap_dio_zero().

   - Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and
     initrd code.

   - Various typo fixes.

  Fixes:

   - Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs()
     call with wait == 1 to commit super blocks. The emergency sync path
     never passed this, leaving btrfs data uncommitted during emergency
     sync.

   - Use local kmap in watch_queue's post_one_notification().

   - Add hint prints in sb_set_blocksize() for LBS dependency on THP"

* tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  MAINTAINERS: add German Maglione as virtiofs co-maintainer
  fs: inline step_into() and walk_component()
  fs: tidy up step_into() & friends before inlining
  orangefs: use inode_update_timestamps directly
  btrfs: fix the comment on btrfs_update_time
  btrfs: use vfs_utimes to update file timestamps
  fs: export vfs_utimes
  fs: lift the FMODE_NOCMTIME check into file_update_time_flags
  fs: refactor file timestamp update logic
  include/linux/fs.h: trivial fix: regualr -> regular
  fs/splice.c: trivial fix: pipes -> pipe's
  fs: mark lookup_slow() as noinline
  fs: add predicts based on nd->depth
  fs: move mntput_no_expire() slowpath into a dedicated routine
  fs: remove spurious exports in fs/file_attr.c
  watch_queue: Use local kmap in post_one_notification()
  fs: touch up predicts in path lookup
  fs: move fd_install() slowpath into a dedicated routine and provide commentary
  fs: hide dentry_cache behind runtime const machinery
  fs: touch predicts in do_dentry_open()
  ...

2 files changed, 17 insertions, 10 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 6282911e536f..8fa80689b5bb 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5839,6 +5839,8 @@ struct btrfs_inode *btrfs_iget(u64 ino, struct btrfs_root *root)
 	if (ret)
 		return ERR_PTR(ret);
 
+	if (S_ISDIR(inode->vfs_inode.i_mode))
+		inode->vfs_inode.i_opflags |= IOP_FASTPERM_MAY_EXEC;
 	unlock_new_inode(&inode->vfs_inode);
 	return inode;
 }
@@ -6291,8 +6293,8 @@ static int btrfs_dirty_inode(struct btrfs_inode *inode)
 }
 
 /*
- * This is a copy of file_update_time.  We need this so we can return error on
- * ENOSPC for updating the inode in the case of file write and mmap writes.
+ * We need our own ->update_time so that we can return error on ENOSPC for
+ * updating the inode in the case of file write and mmap writes.
  */
 static int btrfs_update_time(struct inode *inode, int flags)
 {
@@ -6790,8 +6792,11 @@ static int btrfs_create_common(struct inode *dir, struct dentry *dentry,
 	}
 
 	ret = btrfs_create_new_inode(trans, &new_inode_args);
-	if (!ret)
+	if (!ret) {
+		if (S_ISDIR(inode->i_mode))
+			inode->i_opflags |= IOP_FASTPERM_MAY_EXEC;
 		d_instantiate_new(dentry, inode);
+	}
 
 	btrfs_end_transaction(trans);
 	btrfs_btree_balance_dirty(fs_info);
@@ -9170,6 +9175,11 @@ int btrfs_prealloc_file_range_trans(struct inode *inode,
 					   min_size, actual_len, alloc_hint, trans);
 }
 
+/*
+ * NOTE: in case you are adding MAY_EXEC check for directories:
+ * we are marking them with IOP_FASTPERM_MAY_EXEC, allowing path lookup to
+ * elide calls here.
+ */
 static int btrfs_permission(struct mnt_idmap *idmap,
 			    struct inode *inode, int mask)
 {
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2bec544d8ba3..259e8b0496df 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2002,14 +2002,11 @@ out:
 static void update_dev_time(const char *device_path)
 {
 	struct path path;
-	int ret;
 
-	ret = kern_path(device_path, LOOKUP_FOLLOW, &path);
-	if (ret)
-		return;
-
-	inode_update_time(d_inode(path.dentry), S_MTIME | S_CTIME | S_VERSION);
-	path_put(&path);
+	if (!kern_path(device_path, LOOKUP_FOLLOW, &path)) {
+		vfs_utimes(&path, NULL);
+		path_put(&path);
+	}
 }
 
 static int btrfs_rm_dev_item(struct btrfs_trans_handle *trans,