aufs: file op, open non-dir

Implement f_op->open() for non-directory.
Signed-off-by: J. R. Okajima <hooanon05g@gmail.com>

fs/aufs/Makefile

@@ -15,7 +15,7 @@ aufs-y := module.o sbinfo.o super.o branch.o xino.o sysaufs.o opts.o \
 	cpup.o whout.o wbr_policy.o \
 	dinfo.o dentry.o \
 	dynop.o \
-	finfo.o file.o \
+	finfo.o file.o f_op.o \
 	dir.o vdir.o \
 	iinfo.o inode.o i_op.o i_op_add.o i_op_del.o i_op_ren.o
 

fs/aufs/f_op.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005-2019 Junjiro R. Okajima
+ */
+
+/*
+ * file and vm operations
+ */
+
+#include "aufs.h"
+
+int au_do_open_nondir(struct file *file, int flags)
+{
+	int err;
+	aufs_bindex_t bindex;
+	struct file *h_file;
+	struct dentry *dentry;
+	struct au_finfo *finfo;
+	struct inode *h_inode;
+
+	FiMustWriteLock(file);
+
+	err = 0;
+	dentry = file->f_path.dentry;
+	finfo = au_fi(file);
+	memset(&finfo->fi_htop, 0, sizeof(finfo->fi_htop));
+	bindex = au_dbtop(dentry);
+	h_file = au_h_open(dentry, bindex, flags, file);
+	if (IS_ERR(h_file))
+		err = PTR_ERR(h_file);
+	else {
+		if ((flags & __O_TMPFILE)
+		    && !(flags & O_EXCL)) {
+			h_inode = file_inode(h_file);
+			spin_lock(&h_inode->i_lock);
+			h_inode->i_state |= I_LINKABLE;
+			spin_unlock(&h_inode->i_lock);
+		}
+		au_set_fbtop(file, bindex);
+		au_set_h_fptr(file, bindex, h_file);
+		au_update_figen(file);
+		/* todo: necessary? */
+		/* file->f_ra = h_file->f_ra; */
+	}
+
+	return err;
+}
+
+static int aufs_open_nondir(struct inode *inode __maybe_unused,
+			    struct file *file)
+{
+	int err;
+	struct super_block *sb;
+	struct au_do_open_args args = {
+		.open	= au_do_open_nondir
+	};
+
+	AuDbg("%pD, f_flags 0x%x, f_mode 0x%x\n",
+	      file, vfsub_file_flags(file), file->f_mode);
+
+	sb = file->f_path.dentry->d_sb;
+	si_read_lock(sb, AuLock_FLUSH);
+	err = au_do_open(file, &args);
+	si_read_unlock(sb);
+	return err;
+}
+
+int aufs_release_nondir(struct inode *inode __maybe_unused, struct file *file)
+{
+	struct au_finfo *finfo;
+	aufs_bindex_t bindex;
+
+	finfo = au_fi(file);
+	bindex = finfo->fi_btop;
+	if (bindex >= 0)
+		au_set_h_fptr(file, bindex, NULL);
+
+	au_finfo_fin(file);
+	return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+const struct file_operations aufs_file_fop = {
+	.owner		= THIS_MODULE,
+
+	.open		= aufs_open_nondir,
+	.release	= aufs_release_nondir
+};

fs/aufs/file.c

@@ -82,6 +82,33 @@ out:
 	return h_file;
 }
 
+int au_do_open(struct file *file, struct au_do_open_args *args)
+{
+	int err;
+	struct dentry *dentry;
+	struct au_finfo *finfo;
+
+	err = au_finfo_init(file, args->fidir);
+	if (unlikely(err))
+		goto out;
+
+	dentry = file->f_path.dentry;
+	di_read_lock_child(dentry, AuLock_IR);
+	err = args->open(file, vfsub_file_flags(file));
+	di_read_unlock(dentry, AuLock_IR);
+
+	finfo = au_fi(file);
+	fi_write_unlock(file);
+	if (unlikely(err)) {
+		finfo->fi_hdir = NULL;
+		au_finfo_fin(file);
+	}
+
+out:
+	AuTraceErr(err);
+	return err;
+}
+
 /* ---------------------------------------------------------------------- */
 
 static int au_file_refresh_by_inode(struct file *file, int *need_reopen)

fs/aufs/file.h

@@ -55,9 +55,20 @@ extern const struct address_space_operations aufs_aop;
 unsigned int au_file_roflags(unsigned int flags);
 struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
 		       struct file *file);
+struct au_do_open_args {
+	int		(*open)(struct file *file, int flags);
+	struct au_fidir	*fidir;
+	/* add more later */
+};
+int au_do_open(struct file *file, struct au_do_open_args *args);
 int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
 			  int wlock, unsigned int fi_lsc);
 
+/* f_op.c */
+extern const struct file_operations aufs_file_fop;
+int au_do_open_nondir(struct file *file, int flags);
+int aufs_release_nondir(struct inode *inode __maybe_unused, struct file *file);
+
 /* finfo.c */
 void au_hfput(struct au_hfile *hf, int execed);
 void au_set_h_fptr(struct file *file, aufs_bindex_t bindex,

fs/aufs/inode.c

@@ -214,9 +214,7 @@ static int set_inode(struct inode *inode, struct dentry *dentry)
 	case S_IFREG:
 		btail = au_dbtail(dentry);
 		inode->i_op = iop + AuIop_OTHER;
-#if 0 /* re-commit later */
 		inode->i_fop = &aufs_file_fop;
-#endif
 		err = au_dy_iaop(inode, btop, h_inode);
 		if (unlikely(err))
 			goto out;