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/* SPDX-License-Identifier: GPL-2.0 */
/*
* linux/include/linux/nfs_page.h
*
* Copyright (C) 2000 Trond Myklebust
*
* NFS page cache wrapper.
*/
#ifndef _LINUX_NFS_PAGE_H
#define _LINUX_NFS_PAGE_H
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/wait.h>
#include <linux/sunrpc/auth.h>
#include <linux/nfs_xdr.h>
#include <linux/kref.h>
/*
* Valid flags for a dirty buffer
*/
enum {
PG_BUSY = 0, /* nfs_{un}lock_request */
PG_MAPPED, /* page private set for buffered io */
PG_FOLIO, /* Tracking a folio (unset for O_DIRECT) */
PG_CLEAN, /* write succeeded */
PG_COMMIT_TO_DS, /* used by pnfs layouts */
PG_INODE_REF, /* extra ref held by inode when in writeback */
PG_HEADLOCK, /* page group lock of wb_head */
PG_TEARDOWN, /* page group sync for destroy */
PG_UNLOCKPAGE, /* page group sync bit in read path */
PG_UPTODATE, /* page group sync bit in read path */
PG_WB_END, /* page group sync bit in write path */
PG_REMOVE, /* page group sync bit in write path */
PG_CONTENDED1, /* Is someone waiting for a lock? */
PG_CONTENDED2, /* Is someone waiting for a lock? */
};
struct nfs_inode;
struct nfs_page {
struct list_head wb_list; /* Defines state of page: */
union {
struct page *wb_page; /* page to read in/write out */
struct folio *wb_folio;
};
struct nfs_lock_context *wb_lock_context; /* lock context info */
pgoff_t wb_index; /* Offset >> PAGE_SHIFT */
unsigned int wb_offset, /* Offset & ~PAGE_MASK */
wb_pgbase, /* Start of page data */
wb_bytes; /* Length of request */
struct kref wb_kref; /* reference count */
unsigned long wb_flags;
struct nfs_write_verifier wb_verf; /* Commit cookie */
struct nfs_page *wb_this_page; /* list of reqs for this page */
struct nfs_page *wb_head; /* head pointer for req list */
unsigned short wb_nio; /* Number of I/O attempts */
};
struct nfs_pgio_mirror;
struct nfs_pageio_descriptor;
struct nfs_pageio_ops {
void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *);
size_t (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *,
struct nfs_page *);
int (*pg_doio)(struct nfs_pageio_descriptor *);
unsigned int (*pg_get_mirror_count)(struct nfs_pageio_descriptor *,
struct nfs_page *);
void (*pg_cleanup)(struct nfs_pageio_descriptor *);
struct nfs_pgio_mirror *
(*pg_get_mirror)(struct nfs_pageio_descriptor *, u32);
u32 (*pg_set_mirror)(struct nfs_pageio_descriptor *, u32);
};
struct nfs_rw_ops {
struct nfs_pgio_header *(*rw_alloc_header)(void);
void (*rw_free_header)(struct nfs_pgio_header *);
int (*rw_done)(struct rpc_task *, struct nfs_pgio_header *,
struct inode *);
void (*rw_result)(struct rpc_task *, struct nfs_pgio_header *);
void (*rw_initiate)(struct nfs_pgio_header *, struct rpc_message *,
const struct nfs_rpc_ops *,
struct rpc_task_setup *, int);
};
struct nfs_pgio_mirror {
struct list_head pg_list;
unsigned long pg_bytes_written;
size_t pg_count;
size_t pg_bsize;
unsigned int pg_base;
unsigned char pg_recoalesce : 1;
};
struct nfs_pageio_descriptor {
struct inode *pg_inode;
const struct nfs_pageio_ops *pg_ops;
const struct nfs_rw_ops *pg_rw_ops;
int pg_ioflags;
int pg_error;
const struct rpc_call_ops *pg_rpc_callops;
const struct nfs_pgio_completion_ops *pg_completion_ops;
struct pnfs_layout_segment *pg_lseg;
struct nfs_io_completion *pg_io_completion;
struct nfs_direct_req *pg_dreq;
#ifdef CONFIG_NFS_FSCACHE
void *pg_netfs;
#endif
unsigned int pg_bsize; /* default bsize for mirrors */
u32 pg_mirror_count;
struct nfs_pgio_mirror *pg_mirrors;
struct nfs_pgio_mirror pg_mirrors_static[1];
struct nfs_pgio_mirror *pg_mirrors_dynamic;
u32 pg_mirror_idx; /* current mirror */
unsigned short pg_maxretrans;
unsigned char pg_moreio : 1;
};
/* arbitrarily selected limit to number of mirrors */
#define NFS_PAGEIO_DESCRIPTOR_MIRROR_MAX 16
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
extern struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
struct page *page,
unsigned int pgbase,
loff_t offset,
unsigned int count);
extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
struct folio *folio,
unsigned int offset,
unsigned int count);
extern void nfs_release_request(struct nfs_page *);
extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
struct inode *inode,
const struct nfs_pageio_ops *pg_ops,
const struct nfs_pgio_completion_ops *compl_ops,
const struct nfs_rw_ops *rw_ops,
size_t bsize,
int how);
extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
struct nfs_page *);
extern int nfs_pageio_resend(struct nfs_pageio_descriptor *,
struct nfs_pgio_header *);
extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
extern size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
struct nfs_page *prev,
struct nfs_page *req);
extern int nfs_wait_on_request(struct nfs_page *);
extern void nfs_unlock_request(struct nfs_page *req);
extern void nfs_unlock_and_release_request(struct nfs_page *);
extern struct nfs_page *nfs_page_group_lock_head(struct nfs_page *req);
extern int nfs_page_group_lock_subrequests(struct nfs_page *head);
extern void nfs_join_page_group(struct nfs_page *head,
struct nfs_commit_info *cinfo,
struct inode *inode);
extern int nfs_page_group_lock(struct nfs_page *);
extern void nfs_page_group_unlock(struct nfs_page *);
extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);
extern int nfs_page_set_headlock(struct nfs_page *req);
extern void nfs_page_clear_headlock(struct nfs_page *req);
extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);
/**
* nfs_page_to_folio - Retrieve a struct folio for the request
* @req: pointer to a struct nfs_page
*
* If a folio was assigned to @req, then return it, otherwise return NULL.
*/
static inline struct folio *nfs_page_to_folio(const struct nfs_page *req)
{
if (test_bit(PG_FOLIO, &req->wb_flags))
return req->wb_folio;
return NULL;
}
/**
* nfs_page_to_page - Retrieve a struct page for the request
* @req: pointer to a struct nfs_page
* @pgbase: folio byte offset
*
* Return the page containing the byte that is at offset @pgbase relative
* to the start of the folio.
* Note: The request starts at offset @req->wb_pgbase.
*/
static inline struct page *nfs_page_to_page(const struct nfs_page *req,
size_t pgbase)
{
struct folio *folio = nfs_page_to_folio(req);
if (folio == NULL)
return req->wb_page;
return folio_page(folio, pgbase >> PAGE_SHIFT);
}
/**
* nfs_page_to_inode - Retrieve an inode for the request
* @req: pointer to a struct nfs_page
*/
static inline struct inode *nfs_page_to_inode(const struct nfs_page *req)
{
struct folio *folio = nfs_page_to_folio(req);
if (folio == NULL)
return page_file_mapping(req->wb_page)->host;
return folio_file_mapping(folio)->host;
}
/**
* nfs_page_max_length - Retrieve the maximum possible length for a request
* @req: pointer to a struct nfs_page
*
* Returns the maximum possible length of a request
*/
static inline size_t nfs_page_max_length(const struct nfs_page *req)
{
struct folio *folio = nfs_page_to_folio(req);
if (folio == NULL)
return PAGE_SIZE;
return folio_size(folio);
}
/*
* Lock the page of an asynchronous request
*/
static inline int
nfs_lock_request(struct nfs_page *req)
{
return !test_and_set_bit(PG_BUSY, &req->wb_flags);
}
/**
* nfs_list_add_request - Insert a request into a list
* @req: request
* @head: head of list into which to insert the request.
*/
static inline void
nfs_list_add_request(struct nfs_page *req, struct list_head *head)
{
list_add_tail(&req->wb_list, head);
}
/**
* nfs_list_move_request - Move a request to a new list
* @req: request
* @head: head of list into which to insert the request.
*/
static inline void
nfs_list_move_request(struct nfs_page *req, struct list_head *head)
{
list_move_tail(&req->wb_list, head);
}
/**
* nfs_list_remove_request - Remove a request from its wb_list
* @req: request
*/
static inline void
nfs_list_remove_request(struct nfs_page *req)
{
if (list_empty(&req->wb_list))
return;
list_del_init(&req->wb_list);
}
static inline struct nfs_page *
nfs_list_entry(struct list_head *head)
{
return list_entry(head, struct nfs_page, wb_list);
}
static inline loff_t req_offset(const struct nfs_page *req)
{
return (((loff_t)req->wb_index) << PAGE_SHIFT) + req->wb_offset;
}
static inline struct nfs_open_context *
nfs_req_openctx(struct nfs_page *req)
{
return req->wb_lock_context->open_context;
}
#endif /* _LINUX_NFS_PAGE_H */
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