[net-next-2.6.git] / fs / nfs / pnfs.h

/*
 *  pNFS client data structures.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <dhildebz@umich.edu>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#ifndef FS_NFS_PNFS_H
#define FS_NFS_PNFS_H

struct pnfs_layout_segment {
	struct list_head fi_list;
	struct pnfs_layout_range range;
	struct kref kref;
	struct pnfs_layout_hdr *layout;
};

#ifdef CONFIG_NFS_V4_1

#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"

enum {
	NFS_LAYOUT_RO_FAILED = 0,	/* get ro layout failed stop trying */
	NFS_LAYOUT_RW_FAILED,		/* get rw layout failed stop trying */
	NFS_LAYOUT_STATEID_SET,		/* have a valid layout stateid */
};

/* Per-layout driver specific registration structure */
struct pnfs_layoutdriver_type {
	struct list_head pnfs_tblid;
	const u32 id;
	const char *name;
	struct module *owner;
	int (*set_layoutdriver) (struct nfs_server *);
	int (*clear_layoutdriver) (struct nfs_server *);
	struct pnfs_layout_segment * (*alloc_lseg) (struct pnfs_layout_hdr *layoutid, struct nfs4_layoutget_res *lgr);
	void (*free_lseg) (struct pnfs_layout_segment *lseg);
};

struct pnfs_layout_hdr {
	unsigned long		refcount;
	struct list_head	layouts;   /* other client layouts */
	struct list_head	segs;      /* layout segments list */
	seqlock_t		seqlock;   /* Protects the stateid */
	nfs4_stateid		stateid;
	unsigned long		state;
	struct inode		*inode;
};

struct pnfs_device {
	struct nfs4_deviceid dev_id;
	unsigned int  layout_type;
	unsigned int  mincount;
	struct page **pages;
	void          *area;
	unsigned int  pgbase;
	unsigned int  pglen;
};

/*
 * Device ID RCU cache. A device ID is unique per client ID and layout type.
 */
#define NFS4_DEVICE_ID_HASH_BITS	5
#define NFS4_DEVICE_ID_HASH_SIZE	(1 << NFS4_DEVICE_ID_HASH_BITS)
#define NFS4_DEVICE_ID_HASH_MASK	(NFS4_DEVICE_ID_HASH_SIZE - 1)

static inline u32
nfs4_deviceid_hash(struct nfs4_deviceid *id)
{
	unsigned char *cptr = (unsigned char *)id->data;
	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
	u32 x = 0;

	while (nbytes--) {
		x *= 37;
		x += *cptr++;
	}
	return x & NFS4_DEVICE_ID_HASH_MASK;
}

struct pnfs_deviceid_node {
	struct hlist_node	de_node;
	struct nfs4_deviceid	de_id;
	atomic_t		de_ref;
};

struct pnfs_deviceid_cache {
	spinlock_t		dc_lock;
	atomic_t		dc_ref;
	void			(*dc_free_callback)(struct pnfs_deviceid_node *);
	struct hlist_head	dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
};

extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
			void (*free_callback)(struct pnfs_deviceid_node *));
extern void pnfs_put_deviceid_cache(struct nfs_client *);
extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
				struct pnfs_deviceid_cache *,
				struct nfs4_deviceid *);
extern struct pnfs_deviceid_node *pnfs_add_deviceid(
				struct pnfs_deviceid_cache *,
				struct pnfs_deviceid_node *);
extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
			      struct pnfs_deviceid_node *devid);

extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);

/* nfs4proc.c */
extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
				   struct pnfs_device *dev);
extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);

/* pnfs.c */
struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
		   enum pnfs_iomode access_type);
void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
void unset_pnfs_layoutdriver(struct nfs_server *);
int pnfs_layout_process(struct nfs4_layoutget *lgp);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
void put_layout_hdr(struct inode *inode);
void pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
			     struct nfs4_state *open_state);


static inline int lo_fail_bit(u32 iomode)
{
	return iomode == IOMODE_RW ?
			 NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
}

/* Return true if a layout driver is being used for this mountpoint */
static inline int pnfs_enabled_sb(struct nfs_server *nfss)
{
	return nfss->pnfs_curr_ld != NULL;
}

#else  /* CONFIG_NFS_V4_1 */

static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
{
}

static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
{
}

static inline struct pnfs_layout_segment *
pnfs_update_layout(struct inode *ino, struct nfs_open_context *ctx,
		   enum pnfs_iomode access_type)
{
	return NULL;
}

static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
{
}

static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
{
}

#endif /* CONFIG_NFS_V4_1 */

#endif /* FS_NFS_PNFS_H */
Commit	Line	Data
85e174ba RL	1	/*
	2	* pNFS client data structures.
	3	*
	4	* Copyright (c) 2002
	5	* The Regents of the University of Michigan
	6	* All Rights Reserved
	7	*
	8	* Dean Hildebrand <dhildebz@umich.edu>
	9	*
	10	* Permission is granted to use, copy, create derivative works, and
	11	* redistribute this software and such derivative works for any purpose,
	12	* so long as the name of the University of Michigan is not used in
	13	* any advertising or publicity pertaining to the use or distribution
	14	* of this software without specific, written prior authorization. If
	15	* the above copyright notice or any other identification of the
	16	* University of Michigan is included in any copy of any portion of
	17	* this software, then the disclaimer below must also be included.
	18	*
	19	* This software is provided as is, without representation or warranty
	20	* of any kind either express or implied, including without limitation
	21	* the implied warranties of merchantability, fitness for a particular
	22	* purpose, or noninfringement. The Regents of the University of
	23	* Michigan shall not be liable for any damages, including special,
	24	* indirect, incidental, or consequential damages, with respect to any
	25	* claim arising out of or in connection with the use of the software,
	26	* even if it has been or is hereafter advised of the possibility of
	27	* such damages.
	28	*/
	29
	30	#ifndef FS_NFS_PNFS_H
	31	#define FS_NFS_PNFS_H
	32
974cec8c AA	33	struct pnfs_layout_segment {
974cec8c AA	34	struct list_head fi_list;
b1f69b75	35	struct pnfs_layout_range range;
974cec8c AA	36	struct kref kref;
	37	struct pnfs_layout_hdr *layout;
	38	};
	39
85e174ba RL	40	#ifdef CONFIG_NFS_V4_1
	41
	42	#define LAYOUT_NFSV4_1_MODULE_PREFIX "nfs-layouttype4"
	43
e5e94017 BH	44	enum {
	45	NFS_LAYOUT_RO_FAILED = 0, /* get ro layout failed stop trying */
	46	NFS_LAYOUT_RW_FAILED, /* get rw layout failed stop trying */
b1f69b75	47	NFS_LAYOUT_STATEID_SET, /* have a valid layout stateid */
e5e94017 BH	48	};
e5e94017 BH	49
85e174ba RL	50	/* Per-layout driver specific registration structure */
85e174ba RL	51	struct pnfs_layoutdriver_type {
02c35fca FI	52	struct list_head pnfs_tblid;
	53	const u32 id;
	54	const char *name;
	55	struct module *owner;
1c787096 TM	56	int (set_layoutdriver) (struct nfs_server );
1c787096 TM	57	int (clear_layoutdriver) (struct nfs_server );
b1f69b75 AA	58	struct pnfs_layout_segment * (alloc_lseg) (struct pnfs_layout_hdr layoutid, struct nfs4_layoutget_res *lgr);
b1f69b75 AA	59	void (free_lseg) (struct pnfs_layout_segment lseg);
85e174ba RL	60	};
85e174ba RL	61
e5e94017 BH	62	struct pnfs_layout_hdr {
e5e94017 BH	63	unsigned long refcount;
974cec8c AA	64	struct list_head layouts; /* other client layouts */
974cec8c AA	65	struct list_head segs; /* layout segments list */
b1f69b75 AA	66	seqlock_t seqlock; /* Protects the stateid */
b1f69b75 AA	67	nfs4_stateid stateid;
e5e94017 BH	68	unsigned long state;
	69	struct inode *inode;
	70	};
	71
b1f69b75 AA	72	struct pnfs_device {
	73	struct nfs4_deviceid dev_id;
	74	unsigned int layout_type;
	75	unsigned int mincount;
	76	struct page **pages;
	77	void *area;
	78	unsigned int pgbase;
	79	unsigned int pglen;
	80	};
	81
	82	/*
	83	* Device ID RCU cache. A device ID is unique per client ID and layout type.
	84	*/
	85	#define NFS4_DEVICE_ID_HASH_BITS 5
	86	#define NFS4_DEVICE_ID_HASH_SIZE (1 << NFS4_DEVICE_ID_HASH_BITS)
	87	#define NFS4_DEVICE_ID_HASH_MASK (NFS4_DEVICE_ID_HASH_SIZE - 1)
	88
	89	static inline u32
	90	nfs4_deviceid_hash(struct nfs4_deviceid *id)
	91	{
	92	unsigned char cptr = (unsigned char )id->data;
	93	unsigned int nbytes = NFS4_DEVICEID4_SIZE;
	94	u32 x = 0;
	95
	96	while (nbytes--) {
	97	x *= 37;
	98	x += *cptr++;
	99	}
	100	return x & NFS4_DEVICE_ID_HASH_MASK;
	101	}
	102
	103	struct pnfs_deviceid_node {
	104	struct hlist_node de_node;
	105	struct nfs4_deviceid de_id;
	106	atomic_t de_ref;
	107	};
	108
	109	struct pnfs_deviceid_cache {
	110	spinlock_t dc_lock;
	111	atomic_t dc_ref;
	112	void (dc_free_callback)(struct pnfs_deviceid_node );
	113	struct hlist_head dc_deviceids[NFS4_DEVICE_ID_HASH_SIZE];
	114	};
	115
	116	extern int pnfs_alloc_init_deviceid_cache(struct nfs_client *,
	117	void (free_callback)(struct pnfs_deviceid_node ));
	118	extern void pnfs_put_deviceid_cache(struct nfs_client *);
	119	extern struct pnfs_deviceid_node *pnfs_find_get_deviceid(
	120	struct pnfs_deviceid_cache *,
	121	struct nfs4_deviceid *);
	122	extern struct pnfs_deviceid_node *pnfs_add_deviceid(
	123	struct pnfs_deviceid_cache *,
	124	struct pnfs_deviceid_node *);
	125	extern void pnfs_put_deviceid(struct pnfs_deviceid_cache *c,
	126	struct pnfs_deviceid_node *devid);
	127
02c35fca FI	128	extern int pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *);
	129	extern void pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *);
	130
b1f69b75 AA	131	/* nfs4proc.c */
	132	extern int nfs4_proc_getdeviceinfo(struct nfs_server *server,
	133	struct pnfs_device *dev);
	134	extern int nfs4_proc_layoutget(struct nfs4_layoutget *lgp);
	135
	136	/* pnfs.c */
e5e94017 BH	137	struct pnfs_layout_segment *
	138	pnfs_update_layout(struct inode ino, struct nfs_open_context ctx,
	139	enum pnfs_iomode access_type);
85e174ba RL	140	void set_pnfs_layoutdriver(struct nfs_server *, u32 id);
85e174ba RL	141	void unset_pnfs_layoutdriver(struct nfs_server *);
b1f69b75	142	int pnfs_layout_process(struct nfs4_layoutget *lgp);
e5e94017	143	void pnfs_destroy_layout(struct nfs_inode *);
974cec8c	144	void pnfs_destroy_all_layouts(struct nfs_client *);
b1f69b75 AA	145	void put_layout_hdr(struct inode *inode);
	146	void pnfs_get_layout_stateid(nfs4_stateid dst, struct pnfs_layout_hdr lo,
	147	struct nfs4_state *open_state);
e5e94017 BH	148
	149
	150	static inline int lo_fail_bit(u32 iomode)
	151	{
	152	return iomode == IOMODE_RW ?
	153	NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
	154	}
	155
	156	/* Return true if a layout driver is being used for this mountpoint */
	157	static inline int pnfs_enabled_sb(struct nfs_server *nfss)
	158	{
	159	return nfss->pnfs_curr_ld != NULL;
	160	}
85e174ba RL	161
	162	#else /* CONFIG_NFS_V4_1 */
	163
974cec8c AA	164	static inline void pnfs_destroy_all_layouts(struct nfs_client *clp)
	165	{
	166	}
	167
e5e94017 BH	168	static inline void pnfs_destroy_layout(struct nfs_inode *nfsi)
	169	{
	170	}
	171
	172	static inline struct pnfs_layout_segment *
	173	pnfs_update_layout(struct inode ino, struct nfs_open_context ctx,
	174	enum pnfs_iomode access_type)
	175	{
	176	return NULL;
	177	}
	178
85e174ba RL	179	static inline void set_pnfs_layoutdriver(struct nfs_server *s, u32 id)
	180	{
	181	}
	182
	183	static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
	184	{
	185	}
	186
	187	#endif /* CONFIG_NFS_V4_1 */
	188
	189	#endif /* FS_NFS_PNFS_H */