[PATCH 37/67] aufs file operations

[hooanon05@yahoo.co.jp]

From: Junjiro Okajima <hooanon05@yahoo.co.jp>

	initial commit
	aufs file operations

Signed-off-by: Junjiro Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/file.h |  246 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 246 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/file.h b/fs/aufs/file.h
new file mode 100644
index 0000000..33a1036
--- /dev/null
+++ b/fs/aufs/file.h
@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+ * file operations
+ *
+ * $Id: file.h,v 1.2 2008/04/21 01:35:14 sfjro Exp $
+ */
+
+#ifndef __AUFS_FILE_H__
+#define __AUFS_FILE_H__
+
+#ifdef __KERNEL__
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/aufs_type.h>
+#include "dentry.h"
+#include "misc.h"
+#include "super.h"
+
+/* ---------------------------------------------------------------------- */
+
+struct au_branch;
+struct au_hfile {
+	struct file		*hf_file;
+	struct au_branch	*hf_br;
+};
+
+struct au_vdir;
+struct au_finfo {
+	atomic_t		fi_generation;
+
+	struct au_rwsem		fi_rwsem;
+	struct au_hfile		*fi_hfile;
+	aufs_bindex_t		fi_bstart, fi_bend;
+
+	union {
+		struct vm_operations_struct	*fi_h_vm_ops;
+		struct au_vdir			*fi_vdir_cache;
+	};
+};
+
+/* ---------------------------------------------------------------------- */
+
+/* file.c */
+extern 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);
+int au_do_open(struct inode *inode, struct file *file,
+	       int (*open)(struct file *file, int flags));
+int au_reopen_nondir(struct file *file);
+int au_ready_to_write(struct file *file, loff_t len);
+int au_reval_and_lock_finfo(struct file *file, int (*reopen)(struct file *file),
+			    int wlock, int locked);
+
+/* f_op.c */
+extern struct file_operations aufs_file_fop;
+int aufs_flush(struct file *file, fl_owner_t id);
+
+/* finfo.c */
+struct au_finfo *au_fi(struct file *file);
+struct au_branch *au_fbr(struct file *file, aufs_bindex_t bindex);
+struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex);
+
+void au_hfput(struct au_hfile *hf);
+void au_set_h_fptr(struct file *file, aufs_bindex_t bindex,
+		   struct file *h_file);
+
+void au_finfo_fin(struct file *file);
+int au_finfo_init(struct file *file);
+
+#ifdef CONFIG_AUFS_ROBR
+/* robr.c */
+struct file *au_robr_safe_file(struct vm_area_struct *vma);
+void au_robr_reset_file(struct vm_area_struct *vma, struct file *file);
+#else
+static inline struct file *au_robr_safe_file(struct vm_area_struct *vma)
+{
+	struct file *file;
+
+	file = vma->vm_file;
+	if (file->private_data && au_test_aufs(file->f_dentry->d_sb))
+		return file;
+	return NULL;
+}
+
+static inline
+void au_robr_reset_file(struct vm_area_struct *vma, struct file *file)
+{
+	vma->vm_file = file;
+	//smp_mb(); /* flush vm_file */
+}
+#endif /* CONFIG_AUFS_ROBR */
+
+/* ---------------------------------------------------------------------- */
+
+//todo: memory barrier?
+static inline au_gen_t au_figen(struct file *f)
+{
+	return atomic_read(&au_fi(f)->fi_generation);
+}
+
+static inline int au_test_mmapped(struct file *f)
+{
+	return !!(au_fi(f)->fi_h_vm_ops);
+}
+
+static inline int au_test_aufs_file(struct file *f)
+{
+	return !(f->f_dentry->d_inode->i_mode
+		 & (S_IFCHR | S_IFBLK | S_IFIFO | S_IFSOCK));
+}
+
+/* ---------------------------------------------------------------------- */
+
+#if !defined(CONFIG_AUFS_MODULE) || defined(CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH)
+int au_store_fmode_exec(struct nameidata *nd, struct inode *inode);
+
+static inline int au_deny_write_access(struct file *h_file)
+{
+	LKTRTrace("%.*s\n", AuDLNPair(h_file->f_dentry));
+	return deny_write_access(h_file);
+}
+
+static inline void au_allow_write_access(struct file *h_file)
+{
+	allow_write_access(h_file);
+}
+
+#else
+
+static inline int au_store_fmode_exec(struct nameidata *nd, struct inode *inode)
+{
+	/* nothing */
+	return 0;
+}
+
+static inline int au_deny_write_access(struct file *h_file)
+{
+	/* nothing */
+	return 0;
+}
+
+static inline void au_allow_write_access(struct file *h_file)
+{
+	/* nothing */
+}
+#endif /* CONFIG_AUFS_DENY_WRITE_ACCESS_PATCH */
+
+/* ---------------------------------------------------------------------- */
+
+/*
+ * fi_read_lock, fi_write_lock,
+ * fi_read_unlock, fi_write_unlock, fi_downgrade_lock
+ */
+AuSimpleRwsemFuncs(fi, struct file *f, au_fi(f)->fi_rwsem);
+
+/* to debug easier, do not make them inlined functions */
+#define FiMustReadLock(f) do { \
+	SiMustAnyLock((f)->f_dentry->d_sb); \
+	AuRwMustReadLock(&au_fi(f)->fi_rwsem); \
+} while (0)
+
+#define FiMustWriteLock(f) do { \
+	SiMustAnyLock((f)->f_dentry->d_sb); \
+	AuRwMustWriteLock(&au_fi(f)->fi_rwsem); \
+} while (0)
+
+#define FiMustAnyLock(f) do { \
+	SiMustAnyLock((f)->f_dentry->d_sb); \
+	AuRwMustAnyLock(&au_fi(f)->fi_rwsem); \
+} while (0)
+
+#define FiMustNoWaiters(f)	AuRwMustNoWaiters(&au_fi(f)->fi_rwsem)
+
+/* ---------------------------------------------------------------------- */
+
+// hard/soft set
+static inline aufs_bindex_t au_fbstart(struct file *file)
+{
+	FiMustAnyLock(file);
+	return au_fi(file)->fi_bstart;
+}
+
+static inline aufs_bindex_t au_fbend(struct file *file)
+{
+	FiMustAnyLock(file);
+	return au_fi(file)->fi_bend;
+}
+
+static inline struct au_vdir *au_fvdir_cache(struct file *file)
+{
+	FiMustAnyLock(file);
+	return au_fi(file)->fi_vdir_cache;
+}
+
+static inline void au_set_fbstart(struct file *file, aufs_bindex_t bindex)
+{
+	FiMustWriteLock(file);
+	AuDebugOn(au_sbend(file->f_dentry->d_sb) < bindex);
+	au_fi(file)->fi_bstart = bindex;
+}
+
+static inline void au_set_fbend(struct file *file, aufs_bindex_t bindex)
+{
+	FiMustWriteLock(file);
+	AuDebugOn(au_sbend(file->f_dentry->d_sb) < bindex
+		  || bindex < au_fbstart(file));
+	au_fi(file)->fi_bend = bindex;
+}
+
+static inline void au_set_fvdir_cache(struct file *file,
+				      struct au_vdir *vdir_cache)
+{
+	FiMustWriteLock(file);
+	AuDebugOn(!S_ISDIR(file->f_dentry->d_inode->i_mode)
+		  || (au_fi(file)->fi_vdir_cache && vdir_cache));
+	au_fi(file)->fi_vdir_cache = vdir_cache;
+}
+
+static inline void au_update_figen(struct file *file)
+{
+	atomic_set(&au_fi(file)->fi_generation, au_digen(file->f_dentry));
+	//smp_mb(); /* atomic_set */
+}
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_FILE_H__ */
-- 
1.4.4.4