Date:	Fri, 16 May 2008 23:32:23 +0900
From:	hooanon05@...oo.co.jp
To:	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	Junjiro Okajima <hooanon05@...oo.co.jp>
Subject: [PATCH 9/67] aufs super_block operations

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

	initial commit
	aufs super_block operations

Signed-off-by: Junjiro Okajima <hooanon05@...oo.co.jp>
---
 fs/aufs/super.h |  410 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 410 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/super.h b/fs/aufs/super.h
new file mode 100644
index 0000000..f6e6d8b
--- /dev/null
+++ b/fs/aufs/super.h
@@ -0,0 +1,410 @@
+/*
+ * 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
+ */
+
+/*
+ * super_block operations
+ *
+ * $Id: super.h,v 1.4 2008/05/04 23:52:41 sfjro Exp $
+ */
+
+#ifndef __AUFS_SUPER_H__
+#define __AUFS_SUPER_H__
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h>
+#include <linux/cramfs_fs.h>
+#include <linux/kobject.h>
+#include <linux/magic.h>
+#include <linux/aufs_type.h>
+//#include "hinode.h"
+#include "misc.h"
+//#include "opts.h"
+#include "wkq.h"
+
+typedef ssize_t (*au_readf_t)(struct file *, char __user *, size_t, loff_t *);
+typedef ssize_t (*au_writef_t)(struct file *, const char __user *, size_t,
+			       loff_t *);
+
+struct au_wbr_copyup_operations {
+	int (*copyup)(struct dentry *dentry);
+};
+
+struct au_wbr_create_operations {
+	int (*create)(struct dentry *dentry, int isdir);
+	int (*init)(struct super_block *sb);
+	int (*fin)(struct super_block *sb);
+};
+
+struct au_wbr_mfs {
+	struct mutex	mfs_lock; /* protect this structure */
+	unsigned long	mfs_jiffy;
+	unsigned long	mfs_expire;
+	aufs_bindex_t	mfs_bindex;
+
+	u64		mfsrr_bytes;
+	u64		mfsrr_watermark;
+};
+
+/* sbinfo status flags */
+/*
+ * set true when refresh_dirs() failed at remount time.
+ * then try refreshing dirs at access time again.
+ * if it is false, refreshing dirs at access time is unnecesary
+ */
+#define AuSi_FAILED_REFRESH_DIRS	1
+#define AuSi_FAILED_INIT		(1 << 1)
+#define au_ftest_si(sbinfo, name)	((sbinfo)->au_si_status & AuSi_##name)
+#define au_fset_si(sbinfo, name) \
+	{ (sbinfo)->au_si_status |= AuSi_##name; }
+#define au_fclr_si(sbinfo, name) \
+	{ (sbinfo)->au_si_status &= ~AuSi_##name; }
+
+struct au_branch;
+struct au_sbinfo {
+	/* nowait tasks in the system-wide workqueue */
+	struct au_nowait_tasks	si_nowait;
+
+	struct au_rwsem		si_rwsem;
+
+	/* branch management */
+	au_gen_t		si_generation;
+
+	/* see above flags */
+	unsigned char		au_si_status;
+
+	aufs_bindex_t		si_bend;
+	aufs_bindex_t		si_last_br_id;
+	struct au_branch	**si_branch;
+
+	/* policy to select a writable branch */
+	unsigned char		si_wbr_copyup;
+	unsigned char		si_wbr_create;
+	struct au_wbr_copyup_operations *si_wbr_copyup_ops;
+	struct au_wbr_create_operations *si_wbr_create_ops;
+
+	/* round robin */
+	atomic_t		si_wbr_rr_next;
+
+	/* most free space */
+	struct au_wbr_mfs	si_wbr_mfs;
+
+	/* mount flags */
+	/* include/asm-ia64/siginfo.h defines a macro named si_flags */
+	unsigned int		si_mntflags;
+
+	/* external inode number (bitmap and translation table) */
+	au_readf_t		si_xread;
+	au_writef_t		si_xwrite;
+	struct file		*si_xib;
+	struct mutex		si_xib_mtx; /* protect xib members */
+	unsigned long		*si_xib_buf;
+	unsigned long		si_xib_last_pindex;
+	int			si_xib_next_bit;
+	//unsigned long long	si_xib_limit;	/* Max xib file size */
+
+	/* readdir cache time, max, in HZ */
+	unsigned long		si_rdcache;
+
+	/*
+	 * If the number of whiteouts are larger than si_dirwh, leave all of
+	 * them after au_whtmp_ren to reduce the cost of rmdir(2).
+	 * future fsck.aufs or kernel thread will remove them later.
+	 * Otherwise, remove all whiteouts and the dir in rmdir(2).
+	 */
+	unsigned int		si_dirwh;
+
+	/*
+	 * rename(2) a directory with all children.
+	 */
+	//int			si_rendir;
+
+	/* pseudo_link list */ // dirty
+	spinlock_t		si_plink_lock;
+	struct list_head	si_plink;
+
+	/* dirty, for export, async ops, and sysfs */
+	spinlock_t		si_mntcache_lock;
+	struct vfsmount		*si_mntcache;	/* no get/put */
+
+	/*
+	 * sysfs and lifetime management.
+	 * this is not a small structure and it may be a waste of memory in case
+	 * of sysfs is disabled, particulary when many aufs-es are mounted.
+	 */
+	struct kobject		si_kobj;
+
+	//todo: remove this list.
+	/* super_blocks list is not exported */
+	struct list_head	si_list;
+
+#ifdef CONFIG_AUFS_ROBR
+	/* locked vma list for mmap() */ // dirty
+	spinlock_t		si_lvma_lock;
+	struct list_head	si_lvma;
+#endif
+
+	/* dirty, necessary for unmounting, sysfs and sysrq */
+	struct super_block	*si_sb;
+};
+
+/* ---------------------------------------------------------------------- */
+
+/* policy to select one among writable branches */
+#define AuWbrCopyup(sbinfo, args... ) \
+	(sbinfo)->si_wbr_copyup_ops->copyup(args)
+#define AuWbrCreate(sbinfo, args... ) \
+	(sbinfo)->si_wbr_create_ops->create(args)
+
+/* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
+#define AuLock_DW		1		/* write-lock dentry */
+#define AuLock_IR		(1 << 1)	/* read-lock inode */
+#define AuLock_IW		(1 << 2)	/* write-lock inode */
+#define AuLock_FLUSH		(1 << 3)	/* wait for 'nowait' tasks */
+#define AuLock_DIR		(1 << 4)	/* target is a dir */
+#define au_ftest_lock(flags, name)	((flags) & AuLock_##name)
+#define au_fset_lock(flags, name)	{ (flags) |= AuLock_##name; }
+#define au_fclr_lock(flags, name)	{ (flags) &= ~AuLock_##name; }
+
+/* ---------------------------------------------------------------------- */
+
+/* super.c */
+extern struct file_system_type aufs_fs_type;
+struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
+
+/* sbinfo.c */
+void au_si_free(struct kobject *kobj);
+int au_si_alloc(struct super_block *sb);
+struct au_branch *au_sbr(struct super_block *sb, aufs_bindex_t bindex);
+au_gen_t au_sigen_inc(struct super_block *sb);
+int au_find_bindex(struct super_block *sb, struct au_branch *br);
+
+void aufs_read_lock(struct dentry *dentry, int flags);
+void aufs_read_unlock(struct dentry *dentry, int flags);
+void aufs_write_lock(struct dentry *dentry);
+void aufs_write_unlock(struct dentry *dentry);
+void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int isdir);
+void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
+
+aufs_bindex_t au_new_br_id(struct super_block *sb);
+struct vfsmount *au_mntcache_get(struct super_block *sb);
+
+/* wbr_policy.c */
+extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
+extern struct au_wbr_create_operations au_wbr_create_ops[];
+int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst,
+		   struct dentry *locked);
+
+/* ---------------------------------------------------------------------- */
+
+static inline struct au_sbinfo *au_sbi(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline const char *au_sbtype(struct super_block *sb)
+{
+	return sb->s_type->name;
+}
+
+static inline int au_test_aufs(struct super_block *sb)
+{
+	return (sb->s_magic == AUFS_SUPER_MAGIC);
+}
+
+static inline int au_test_nfs(struct super_block *sb)
+{
+#ifdef CONFIG_AUFS_BR_NFS
+	return (sb->s_magic == NFS_SUPER_MAGIC);
+#else
+	return 0;
+#endif
+}
+
+static inline int au_test_fuse(struct super_block *sb)
+{
+#ifdef CONFIG_AUFS_WORKAROUND_FUSE
+#ifdef FUSE_SUPER_MAGIC
+	BUILD_BUG_ON(FUSE_SUPER_MAGIC != 0x65735546);
+	return (sb->s_magic == FUSE_SUPER_MAGIC);
+#else
+	return !strcmp(au_sbtype(sb), "fuse");
+#endif
+#endif
+	return 0;
+}
+
+static inline int au_test_xfs(struct super_block *sb)
+{
+#ifdef CONFIG_AUFS_BR_XFS
+#ifdef XFS_SB_MAGIC
+	BUILD_BUG_ON(XFS_SB_MAGIC != 0x58465342);
+	return (sb->s_magic == XFS_SB_MAGIC);
+#else
+	return !strcmp(au_sbtype(sb), "xfs");
+#endif
+#endif
+	return 0;
+}
+
+static inline int au_test_tmpfs(struct super_block *sb)
+{
+#ifdef CONFIG_TMPFS
+#ifdef TMPFS_MAGIC
+	BUILD_BUG_ON(TMPFS_MAGIC != 0x01021994);
+	return (sb->s_magic == TMPFS_MAGIC);
+#else
+	return !strcmp(au_sbtype(sb), "tmpfs");
+#endif
+#endif
+	return 0;
+}
+
+/* ---------------------------------------------------------------------- */
+
+#ifdef CONFIG_AUFS_EXPORT
+extern struct export_operations aufs_export_op;
+static inline void au_init_export_op(struct super_block *sb)
+{
+	sb->s_export_op = &aufs_export_op;
+}
+
+static inline int au_test_nfsd(struct task_struct *tsk)
+{
+	return (!tsk->mm && !strcmp(tsk->comm, "nfsd"));
+}
+
+static inline void au_nfsd_lockdep_off(void)
+{
+	if (au_test_nfsd(current))
+		lockdep_off();
+}
+
+static inline void au_nfsd_lockdep_on(void)
+{
+	if (au_test_nfsd(current))
+		lockdep_on();
+}
+#else
+static inline int au_test_nfsd(struct task_struct *tsk)
+{
+	return 0;
+}
+
+static inline void au_init_export_op(struct super_block *sb)
+{
+	/* nothing */
+}
+
+#define au_nfsd_lockdep_off()	do {} while (0)
+#define au_nfsd_lockdep_on()	do {} while (0)
+#endif /* CONFIG_AUFS_EXPORT */
+
+#ifdef CONFIG_AUFS_ROBR
+static inline int au_test_nested(struct super_block *h_sb)
+{
+	return 0;
+}
+
+static inline void au_robr_lvma_init(struct au_sbinfo *sbinfo)
+{
+	spin_lock_init(&sbinfo->si_lvma_lock);
+	INIT_LIST_HEAD(&sbinfo->si_lvma);
+}
+#else
+static inline int au_test_nested(struct super_block *h_sb)
+{
+	int err = 0;
+	if (unlikely(au_test_aufs(h_sb))) {
+		err = -EINVAL;
+		AuTraceErr(err);
+	}
+	return err;
+}
+
+static inline void au_robr_lvma_init(struct au_sbinfo *sbinfo)
+{
+	/* empty */
+}
+#endif /* CONFIG_AUFS_ROBR */
+
+/* ---------------------------------------------------------------------- */
+
+/* lock superblock. mainly for entry point functions */
+/*
+ * si_noflush_read_lock, si_noflush_write_lock,
+ * si_read_unlock, si_write_unlock, si_downgrade_lock
+ */
+AuSimpleLockRwsemFuncs(si_noflush, struct super_block *sb,
+		       au_sbi(sb)->si_rwsem);
+AuSimpleUnlockRwsemFuncs(si, struct super_block *sb, au_sbi(sb)->si_rwsem);
+
+static inline void si_read_lock(struct super_block *sb, int flags)
+{
+	if (au_ftest_lock(flags, FLUSH))
+		au_nwt_flush(&au_sbi(sb)->si_nowait);
+	si_noflush_read_lock(sb);
+}
+
+static inline void si_write_lock(struct super_block *sb)
+{
+	au_nwt_flush(&au_sbi(sb)->si_nowait);
+	si_noflush_write_lock(sb);
+}
+
+static inline int si_read_trylock(struct super_block *sb, int flags)
+{
+	if (au_ftest_lock(flags, FLUSH))
+		au_nwt_flush(&au_sbi(sb)->si_nowait);
+	return si_noflush_read_trylock(sb);
+}
+
+static inline int si_write_trylock(struct super_block *sb, int flags)
+{
+	if (au_ftest_lock(flags, FLUSH))
+		au_nwt_flush(&au_sbi(sb)->si_nowait);
+	return si_noflush_write_trylock(sb);
+}
+
+/* to debug easier, do not make them inlined functions */
+#define SiMustReadLock(sb)	AuRwMustReadLock(&au_sbi(sb)->si_rwsem)
+#define SiMustWriteLock(sb)	AuRwMustWriteLock(&au_sbi(sb)->si_rwsem)
+#define SiMustAnyLock(sb)	AuRwMustAnyLock(&au_sbi(sb)->si_rwsem)
+
+/* ---------------------------------------------------------------------- */
+
+static inline aufs_bindex_t au_sbend(struct super_block *sb)
+{
+	SiMustAnyLock(sb);
+	return au_sbi(sb)->si_bend;
+}
+
+static inline unsigned int au_mntflags(struct super_block *sb)
+{
+	SiMustAnyLock(sb);
+	return au_sbi(sb)->si_mntflags;
+}
+
+static inline au_gen_t au_sigen(struct super_block *sb)
+{
+	SiMustAnyLock(sb);
+	return au_sbi(sb)->si_generation;
+}
+
+#endif /* __KERNEL__ */
+#endif /* __AUFS_SUPER_H__ */
-- 
1.4.4.4

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