nfs_fs.h

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/*
 *  linux/include/linux/nfs_fs.h
 *
 *  Copyright (C) 1992  Rick Sladkey
 *
 *  OS-specific nfs filesystem definitions and declarations
 */

#ifndef _LINUX_NFS_FS_H
#define _LINUX_NFS_FS_H

#include <linux/config.h>
#include <linux/in.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/rwsem.h>
#include <linux/wait.h>
#include <linux/uio.h>

#include <linux/nfs_fs_sb.h>

#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/auth.h>
#include <linux/sunrpc/clnt.h>

#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
#include <linux/nfs4.h>
#include <linux/nfs_xdr.h>
#include <linux/rwsem.h>
#include <linux/workqueue.h>

/*
 * Enable debugging support for nfs client.
 * Requires RPC_DEBUG.
 */
#ifdef RPC_DEBUG
# define NFS_DEBUG
#endif

#define NFS_MAX_FILE_IO_BUFFER_SIZE	32768
#define NFS_DEF_FILE_IO_BUFFER_SIZE	4096

/*
 * The upper limit on timeouts for the exponential backoff algorithm.
 */
#define NFS_WRITEBACK_DELAY		(5*HZ)
#define NFS_WRITEBACK_LOCKDELAY		(60*HZ)
#define NFS_COMMIT_DELAY		(5*HZ)

/*
 * superblock magic number for NFS
 */
#define NFS_SUPER_MAGIC			0x6969

/*
 * These are the default flags for swap requests
 */
#define NFS_RPC_SWAPFLAGS		(RPC_TASK_SWAPPER|RPC_TASK_ROOTCREDS)

#define NFS_RW_SYNC		0x0001	/* O_SYNC handling */
#define NFS_RW_SWAP		0x0002	/* This is a swap request */

/*
 * When flushing a cluster of dirty pages, there can be different
 * strategies:
 */
#define FLUSH_AGING		0	/* only flush old buffers */
#define FLUSH_SYNC		1	/* file being synced, or contention */
#define FLUSH_WAIT		2	/* wait for completion */
#define FLUSH_STABLE		4	/* commit to stable storage */
#define FLUSH_LOWPRI		8	/* low priority background flush */
#define FLUSH_HIGHPRI		16	/* high priority memory reclaim flush */

#ifdef __KERNEL__

/*
 * NFSv3/v4 Access mode cache entry
 */
struct nfs_access_entry {
	unsigned long		jiffies;
	struct rpc_cred *	cred;
	int			mask;
};

struct nfs4_state;
struct nfs_open_context {
	atomic_t count;
	struct dentry *dentry;
	struct rpc_cred *cred;
	struct nfs4_state *state;
	fl_owner_t lockowner;
	int mode;
	int error;

	struct list_head list;
	wait_queue_head_t waitq;
};

/*
 * NFSv4 delegation
 */
struct nfs_delegation;

/*
 * nfs fs inode data in memory
 */
struct nfs_inode {
	/*
	 * The 64bit 'inode number'
	 */
	__u64 fileid;

	/*
	 * NFS file handle
	 */
	struct nfs_fh		fh;

	/*
	 * Various flags
	 */
	unsigned int		flags;

	/*
	 * read_cache_jiffies is when we started read-caching this inode,
	 * and read_cache_mtime is the mtime of the inode at that time.
	 * attrtimeo is for how long the cached information is assumed
	 * to be valid. A successful attribute revalidation doubles
	 * attrtimeo (up to acregmax/acdirmax), a failure resets it to
	 * acregmin/acdirmin.
	 *
	 * We need to revalidate the cached attrs for this inode if
	 *
	 *	jiffies - read_cache_jiffies > attrtimeo
	 *
	 * and invalidate any cached data/flush out any dirty pages if
	 * we find that
	 *
	 *	mtime != read_cache_mtime
	 */
	unsigned long		readdir_timestamp;
	unsigned long		read_cache_jiffies;
	unsigned long		attrtimeo;
	unsigned long		attrtimeo_timestamp;
	__u64			change_attr;		/* v4 only */

	/* "Generation counter" for the attribute cache. This is
	 * bumped whenever we update the metadata on the
	 * server.
	 */
	unsigned long		cache_change_attribute;
	/*
	 * Counter indicating the number of outstanding requests that
	 * will cause a file data update.
	 */
	atomic_t		data_updates;

	struct nfs_access_entry	cache_access;

	/*
	 * This is the cookie verifier used for NFSv3 readdir
	 * operations
	 */
	__u32			cookieverf[2];

	/*
	 * This is the list of dirty unwritten pages.
	 */
	spinlock_t		req_lock;
	struct list_head	dirty;
	struct list_head	commit;
	struct radix_tree_root	nfs_page_tree;

	unsigned int		ndirty,
				ncommit,
				npages;

	/* Open contexts for shared mmap writes */
	struct list_head	open_files;

	wait_queue_head_t	nfs_i_wait;

#ifdef CONFIG_NFS_V4
        /* NFSv4 state */
	struct list_head	open_states;
	struct nfs_delegation	*delegation;
	int			 delegation_state;
	struct rw_semaphore	rwsem;
#endif /* CONFIG_NFS_V4*/

	struct inode		vfs_inode;
};

/*
 * Legal inode flag values
 */
#define NFS_INO_STALE		0x0001		/* possible stale inode */
#define NFS_INO_ADVISE_RDPLUS   0x0002          /* advise readdirplus */
#define NFS_INO_REVALIDATING	0x0004		/* revalidating attrs */
#define NFS_INO_INVALID_ATTR	0x0008		/* cached attrs are invalid */
#define NFS_INO_INVALID_DATA	0x0010		/* cached data is invalid */
#define NFS_INO_INVALID_ATIME	0x0020		/* cached atime is invalid */

static inline struct nfs_inode *NFS_I(struct inode *inode)
{
	return container_of(inode, struct nfs_inode, vfs_inode);
}
#define NFS_SB(s)		((struct nfs_server *)(s->s_fs_info))

#define NFS_FH(inode)			(&NFS_I(inode)->fh)
#define NFS_SERVER(inode)		(NFS_SB(inode->i_sb))
#define NFS_CLIENT(inode)		(NFS_SERVER(inode)->client)
#define NFS_PROTO(inode)		(NFS_SERVER(inode)->rpc_ops)
#define NFS_ADDR(inode)			(RPC_PEERADDR(NFS_CLIENT(inode)))
#define NFS_COOKIEVERF(inode)		(NFS_I(inode)->cookieverf)
#define NFS_READTIME(inode)		(NFS_I(inode)->read_cache_jiffies)
#define NFS_CHANGE_ATTR(inode)		(NFS_I(inode)->change_attr)
#define NFS_ATTRTIMEO(inode)		(NFS_I(inode)->attrtimeo)
#define NFS_MINATTRTIMEO(inode) \
	(S_ISDIR(inode->i_mode)? NFS_SERVER(inode)->acdirmin \
			       : NFS_SERVER(inode)->acregmin)
#define NFS_MAXATTRTIMEO(inode) \
	(S_ISDIR(inode->i_mode)? NFS_SERVER(inode)->acdirmax \
			       : NFS_SERVER(inode)->acregmax)
#define NFS_ATTRTIMEO_UPDATE(inode)	(NFS_I(inode)->attrtimeo_timestamp)

#define NFS_FLAGS(inode)		(NFS_I(inode)->flags)
#define NFS_REVALIDATING(inode)		(NFS_FLAGS(inode) & NFS_INO_REVALIDATING)
#define NFS_STALE(inode)		(NFS_FLAGS(inode) & NFS_INO_STALE)

#define NFS_FILEID(inode)		(NFS_I(inode)->fileid)

static inline int nfs_caches_unstable(struct inode *inode)
{
	return atomic_read(&NFS_I(inode)->data_updates) != 0;
}

static inline void NFS_CACHEINV(struct inode *inode)
{
	if (!nfs_caches_unstable(inode))
		NFS_FLAGS(inode) |= NFS_INO_INVALID_ATTR;
}

static inline int nfs_server_capable(struct inode *inode, int cap)
{
	return NFS_SERVER(inode)->caps & cap;
}

static inline int NFS_USE_READDIRPLUS(struct inode *inode)
{
	return NFS_FLAGS(inode) & NFS_INO_ADVISE_RDPLUS;
}

static inline
loff_t page_offset(struct page *page)
{
	return ((loff_t)page->index) << PAGE_CACHE_SHIFT;
}

/**
 * nfs_save_change_attribute - Returns the inode attribute change cookie
 * @inode - pointer to inode
 * The "change attribute" is updated every time we finish an operation
 * that will result in a metadata change on the server.
 */
static inline long nfs_save_change_attribute(struct inode *inode)
{
	return NFS_I(inode)->cache_change_attribute;
}

/**
 * nfs_verify_change_attribute - Detects NFS inode cache updates
 * @inode - pointer to inode
 * @chattr - previously saved change attribute
 * Return "false" if metadata has been updated (or is in the process of
 * being updated) since the change attribute was saved.
 */
static inline int nfs_verify_change_attribute(struct inode *inode, unsigned long chattr)
{
	return !nfs_caches_unstable(inode)
		&& chattr == NFS_I(inode)->cache_change_attribute;
}

/*
 * linux/fs/nfs/inode.c
 */
extern void nfs_zap_caches(struct inode *);
extern struct inode *nfs_fhget(struct super_block *, struct nfs_fh *,
				struct nfs_fattr *);
extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *);
extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
extern int nfs_permission(struct inode *, int, struct nameidata *);
extern int nfs_access_get_cached(struct inode *, struct rpc_cred *, struct nfs_access_entry *);
extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
extern int nfs_open(struct inode *, struct file *);
extern int nfs_release(struct inode *, struct file *);
extern int nfs_attribute_timeout(struct inode *inode);
extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
extern int nfs_setattr(struct dentry *, struct iattr *);
extern void nfs_begin_attr_update(struct inode *);
extern void nfs_end_attr_update(struct inode *);
extern void nfs_begin_data_update(struct inode *);
extern void nfs_end_data_update(struct inode *);
extern void nfs_end_data_update_defer(struct inode *);
extern struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, struct rpc_cred *cred);
extern struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx);
extern void put_nfs_open_context(struct nfs_open_context *ctx);
extern void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx);
extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, int mode);
extern void nfs_file_clear_open_context(struct file *filp);

/* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
extern u32 root_nfs_parse_addr(char *name); /*__init*/

/*
 * linux/fs/nfs/file.c
 */
extern struct inode_operations nfs_file_inode_operations;
extern struct file_operations nfs_file_operations;
extern struct address_space_operations nfs_file_aops;

static inline struct rpc_cred *nfs_file_cred(struct file *file)
{
	if (file != NULL) {
		struct nfs_open_context *ctx;

		ctx = (struct nfs_open_context*)file->private_data;
		return ctx->cred;
	}
	return NULL;
}

/*
 * linux/fs/nfs/direct.c
 */
extern ssize_t nfs_direct_IO(int, struct kiocb *, const struct iovec *, loff_t,
			unsigned long);
extern ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf,
			size_t count, loff_t pos);
extern ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf,
			size_t count, loff_t pos);

/*
 * linux/fs/nfs/dir.c
 */
extern struct inode_operations nfs_dir_inode_operations;
extern struct file_operations nfs_dir_operations;
extern struct dentry_operations nfs_dentry_operations;

/*
 * linux/fs/nfs/symlink.c
 */
extern struct inode_operations nfs_symlink_inode_operations;

/*
 * linux/fs/nfs/locks.c
 */
extern int nfs_lock(struct file *, int, struct file_lock *);

/*
 * linux/fs/nfs/unlink.c
 */
extern int  nfs_async_unlink(struct dentry *);