1 /* SPDX-License-Identifier: GPL-2.0 */
3 * linux/include/linux/nfs_page.h
5 * Copyright (C) 2000 Trond Myklebust
7 * NFS page cache wrapper.
10 #ifndef _LINUX_NFS_PAGE_H
11 #define _LINUX_NFS_PAGE_H
14 #include <linux/list.h>
15 #include <linux/pagemap.h>
16 #include <linux/wait.h>
17 #include <linux/sunrpc/auth.h>
18 #include <linux/nfs_xdr.h>
20 #include <linux/kref.h>
23 * Valid flags for a dirty buffer
26 PG_BUSY
= 0, /* nfs_{un}lock_request */
27 PG_MAPPED
, /* page private set for buffered io */
28 PG_CLEAN
, /* write succeeded */
29 PG_COMMIT_TO_DS
, /* used by pnfs layouts */
30 PG_INODE_REF
, /* extra ref held by inode when in writeback */
31 PG_HEADLOCK
, /* page group lock of wb_head */
32 PG_TEARDOWN
, /* page group sync for destroy */
33 PG_UNLOCKPAGE
, /* page group sync bit in read path */
34 PG_UPTODATE
, /* page group sync bit in read path */
35 PG_WB_END
, /* page group sync bit in write path */
36 PG_REMOVE
, /* page group sync bit in write path */
37 PG_CONTENDED1
, /* Is someone waiting for a lock? */
38 PG_CONTENDED2
, /* Is someone waiting for a lock? */
43 struct list_head wb_list
; /* Defines state of page: */
44 struct page
*wb_page
; /* page to read in/write out */
45 struct nfs_lock_context
*wb_lock_context
; /* lock context info */
46 pgoff_t wb_index
; /* Offset >> PAGE_SHIFT */
47 unsigned int wb_offset
, /* Offset & ~PAGE_MASK */
48 wb_pgbase
, /* Start of page data */
49 wb_bytes
; /* Length of request */
50 struct kref wb_kref
; /* reference count */
51 unsigned long wb_flags
;
52 struct nfs_write_verifier wb_verf
; /* Commit cookie */
53 struct nfs_page
*wb_this_page
; /* list of reqs for this page */
54 struct nfs_page
*wb_head
; /* head pointer for req list */
55 unsigned short wb_nio
; /* Number of I/O attempts */
58 struct nfs_pgio_mirror
;
59 struct nfs_pageio_descriptor
;
60 struct nfs_pageio_ops
{
61 void (*pg_init
)(struct nfs_pageio_descriptor
*, struct nfs_page
*);
62 size_t (*pg_test
)(struct nfs_pageio_descriptor
*, struct nfs_page
*,
64 int (*pg_doio
)(struct nfs_pageio_descriptor
*);
65 unsigned int (*pg_get_mirror_count
)(struct nfs_pageio_descriptor
*,
67 void (*pg_cleanup
)(struct nfs_pageio_descriptor
*);
68 struct nfs_pgio_mirror
*
69 (*pg_get_mirror
)(struct nfs_pageio_descriptor
*, u32
);
70 u32 (*pg_set_mirror
)(struct nfs_pageio_descriptor
*, u32
);
74 struct nfs_pgio_header
*(*rw_alloc_header
)(void);
75 void (*rw_free_header
)(struct nfs_pgio_header
*);
76 int (*rw_done
)(struct rpc_task
*, struct nfs_pgio_header
*,
78 void (*rw_result
)(struct rpc_task
*, struct nfs_pgio_header
*);
79 void (*rw_initiate
)(struct nfs_pgio_header
*, struct rpc_message
*,
80 const struct nfs_rpc_ops
*,
81 struct rpc_task_setup
*, int);
84 struct nfs_pgio_mirror
{
85 struct list_head pg_list
;
86 unsigned long pg_bytes_written
;
90 unsigned char pg_recoalesce
: 1;
93 struct nfs_pageio_descriptor
{
94 struct inode
*pg_inode
;
95 const struct nfs_pageio_ops
*pg_ops
;
96 const struct nfs_rw_ops
*pg_rw_ops
;
99 const struct rpc_call_ops
*pg_rpc_callops
;
100 const struct nfs_pgio_completion_ops
*pg_completion_ops
;
101 struct pnfs_layout_segment
*pg_lseg
;
102 struct nfs_io_completion
*pg_io_completion
;
103 struct nfs_direct_req
*pg_dreq
;
104 unsigned int pg_bsize
; /* default bsize for mirrors */
107 struct nfs_pgio_mirror
*pg_mirrors
;
108 struct nfs_pgio_mirror pg_mirrors_static
[1];
109 struct nfs_pgio_mirror
*pg_mirrors_dynamic
;
110 u32 pg_mirror_idx
; /* current mirror */
111 unsigned short pg_maxretrans
;
112 unsigned char pg_moreio
: 1;
115 /* arbitrarily selected limit to number of mirrors */
116 #define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
118 #define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
120 extern struct nfs_page
*nfs_create_request(struct nfs_open_context
*ctx
,
124 extern void nfs_release_request(struct nfs_page
*);
127 extern void nfs_pageio_init(struct nfs_pageio_descriptor
*desc
,
129 const struct nfs_pageio_ops
*pg_ops
,
130 const struct nfs_pgio_completion_ops
*compl_ops
,
131 const struct nfs_rw_ops
*rw_ops
,
134 extern int nfs_pageio_add_request(struct nfs_pageio_descriptor
*,
136 extern int nfs_pageio_resend(struct nfs_pageio_descriptor
*,
137 struct nfs_pgio_header
*);
138 extern void nfs_pageio_complete(struct nfs_pageio_descriptor
*desc
);
139 extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor
*, pgoff_t
);
140 extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor
*desc
,
141 struct nfs_page
*prev
,
142 struct nfs_page
*req
);
143 extern int nfs_wait_on_request(struct nfs_page
*);
144 extern void nfs_unlock_request(struct nfs_page
*req
);
145 extern void nfs_unlock_and_release_request(struct nfs_page
*);
146 extern struct nfs_page
*nfs_page_group_lock_head(struct nfs_page
*req
);
147 extern int nfs_page_group_lock_subrequests(struct nfs_page
*head
);
148 extern void nfs_join_page_group(struct nfs_page
*head
, struct inode
*inode
);
149 extern int nfs_page_group_lock(struct nfs_page
*);
150 extern void nfs_page_group_unlock(struct nfs_page
*);
151 extern bool nfs_page_group_sync_on_bit(struct nfs_page
*, unsigned int);
152 extern int nfs_page_set_headlock(struct nfs_page
*req
);
153 extern void nfs_page_clear_headlock(struct nfs_page
*req
);
154 extern bool nfs_async_iocounter_wait(struct rpc_task
*, struct nfs_lock_context
*);
157 * Lock the page of an asynchronous request
160 nfs_lock_request(struct nfs_page
*req
)
162 return !test_and_set_bit(PG_BUSY
, &req
->wb_flags
);
166 * nfs_list_add_request - Insert a request into a list
168 * @head: head of list into which to insert the request.
171 nfs_list_add_request(struct nfs_page
*req
, struct list_head
*head
)
173 list_add_tail(&req
->wb_list
, head
);
177 * nfs_list_move_request - Move a request to a new list
179 * @head: head of list into which to insert the request.
182 nfs_list_move_request(struct nfs_page
*req
, struct list_head
*head
)
184 list_move_tail(&req
->wb_list
, head
);
188 * nfs_list_remove_request - Remove a request from its wb_list
192 nfs_list_remove_request(struct nfs_page
*req
)
194 if (list_empty(&req
->wb_list
))
196 list_del_init(&req
->wb_list
);
199 static inline struct nfs_page
*
200 nfs_list_entry(struct list_head
*head
)
202 return list_entry(head
, struct nfs_page
, wb_list
);
206 loff_t
req_offset(struct nfs_page
*req
)
208 return (((loff_t
)req
->wb_index
) << PAGE_SHIFT
) + req
->wb_offset
;
211 static inline struct nfs_open_context
*
212 nfs_req_openctx(struct nfs_page
*req
)
214 return req
->wb_lock_context
->open_context
;
217 #endif /* _LINUX_NFS_PAGE_H */