linux/fs/nfs/pnfs.h
Fred Isaman f7e8917a67 pnfs: layout roc code
A layout can request return-on-close.  How this interacts with the
forgetful model of never sending LAYOUTRETURNS is a bit ambiguous.
We forget any layouts marked roc, and wait for them to be completely
forgotten before continuing with the close.  In addition, to compensate
for races with any inflight LAYOUTGETs, and the fact that we do not get
any layout stateid back from the server, we set the barrier to the worst
case scenario of current_seqid + number of outstanding LAYOUTGETS.

Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:32 -05:00

236 lines
6.9 KiB
C

/*
* 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
enum {
NFS_LSEG_VALID = 0, /* cleared when lseg is recalled/returned */
NFS_LSEG_ROC, /* roc bit received from server */
};
struct pnfs_layout_segment {
struct list_head pls_list;
struct pnfs_layout_range pls_range;
atomic_t pls_refcount;
unsigned long pls_flags;
struct pnfs_layout_hdr *pls_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_BULK_RECALL, /* bulk recall affecting layout */
NFS_LAYOUT_ROC, /* some lseg had roc bit set */
NFS_LAYOUT_DESTROYED, /* no new use of layout allowed */
};
/* 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 {
atomic_t plh_refcount;
struct list_head plh_layouts; /* other client layouts */
struct list_head plh_bulk_recall; /* clnt list of bulk recalls */
struct list_head plh_segs; /* layout segments list */
nfs4_stateid plh_stateid;
atomic_t plh_outstanding; /* number of RPCs out */
unsigned long plh_block_lgets; /* block LAYOUTGET if >0 */
u32 plh_barrier; /* ignore lower seqids */
unsigned long plh_flags;
struct inode *plh_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 */
void get_layout_hdr(struct pnfs_layout_hdr *lo);
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_free_lseg_list(struct list_head *tmp_list);
void pnfs_destroy_layout(struct nfs_inode *);
void pnfs_destroy_all_layouts(struct nfs_client *);
void put_layout_hdr(struct pnfs_layout_hdr *lo);
void pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo,
const nfs4_stateid *new,
bool update_barrier);
int pnfs_choose_layoutget_stateid(nfs4_stateid *dst,
struct pnfs_layout_hdr *lo,
struct nfs4_state *open_state);
int mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
struct list_head *tmp_list,
u32 iomode);
bool pnfs_roc(struct inode *ino);
void pnfs_roc_release(struct inode *ino);
void pnfs_roc_set_barrier(struct inode *ino, u32 barrier);
bool pnfs_roc_drain(struct inode *ino, u32 *barrier);
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 bool
pnfs_roc(struct inode *ino)
{
return false;
}
static inline void
pnfs_roc_release(struct inode *ino)
{
}
static inline void
pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
{
}
static inline bool
pnfs_roc_drain(struct inode *ino, u32 *barrier)
{
return false;
}
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 */