a861a1e1c3
We create three major hooks for the pnfs code. pnfs_mark_request_commit() is called during writeback_done from nfs_mark_request_commit, which gives the driver an opportunity to claim it wants control over commiting a particular req. pnfs_choose_commit_list() is called from nfs_scan_list to choose which list a given req should be added to, based on where we intend to send it for COMMIT. It is up to the driver to have preallocated list headers for each destination it may need. pnfs_commit_list() is how the driver actually takes control, it is used instead of nfs_commit_list(). In order to pass information between the above functions, we create a union in nfs_page to hold a lseg (which is possible because the req is not on any list while in transition), and add some flags to indicate if we need to use the pnfs code. Signed-off-by: Fred Isaman <iisaman@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
147 lines
3.8 KiB
C
147 lines
3.8 KiB
C
/*
|
|
* 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 the radix tree
|
|
*/
|
|
#define NFS_PAGE_TAG_LOCKED 0
|
|
#define NFS_PAGE_TAG_COMMIT 1
|
|
|
|
/*
|
|
* Valid flags for a dirty buffer
|
|
*/
|
|
enum {
|
|
PG_BUSY = 0,
|
|
PG_MAPPED,
|
|
PG_CLEAN,
|
|
PG_NEED_COMMIT,
|
|
PG_NEED_RESCHED,
|
|
PG_PNFS_COMMIT,
|
|
};
|
|
|
|
struct nfs_inode;
|
|
struct nfs_page {
|
|
union {
|
|
struct list_head wb_list; /* Defines state of page: */
|
|
struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
|
|
};
|
|
struct page *wb_page; /* page to read in/write out */
|
|
struct nfs_open_context *wb_context; /* File state context info */
|
|
struct nfs_lock_context *wb_lock_context; /* lock context info */
|
|
atomic_t wb_complete; /* i/os we're waiting for */
|
|
pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
|
|
unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
|
|
wb_pgbase, /* Start of page data */
|
|
wb_bytes; /* Length of request */
|
|
struct kref wb_kref; /* reference count */
|
|
unsigned long wb_flags;
|
|
struct nfs_writeverf wb_verf; /* Commit cookie */
|
|
};
|
|
|
|
struct nfs_pageio_descriptor {
|
|
struct list_head pg_list;
|
|
unsigned long pg_bytes_written;
|
|
size_t pg_count;
|
|
size_t pg_bsize;
|
|
unsigned int pg_base;
|
|
char pg_moreio;
|
|
|
|
struct inode *pg_inode;
|
|
int (*pg_doio)(struct nfs_pageio_descriptor *);
|
|
int pg_ioflags;
|
|
int pg_error;
|
|
struct pnfs_layout_segment *pg_lseg;
|
|
int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
|
|
};
|
|
|
|
#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
|
|
|
|
extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
|
|
struct inode *inode,
|
|
struct page *page,
|
|
unsigned int offset,
|
|
unsigned int count);
|
|
extern void nfs_clear_request(struct nfs_page *req);
|
|
extern void nfs_release_request(struct nfs_page *req);
|
|
|
|
|
|
extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
|
|
pgoff_t idx_start, unsigned int npages, int tag);
|
|
extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
|
|
struct inode *inode,
|
|
int (*doio)(struct nfs_pageio_descriptor *desc),
|
|
size_t bsize,
|
|
int how);
|
|
extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
|
|
struct nfs_page *);
|
|
extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
|
|
extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
|
|
extern int nfs_wait_on_request(struct nfs_page *);
|
|
extern void nfs_unlock_request(struct nfs_page *req);
|
|
extern int nfs_set_page_tag_locked(struct nfs_page *req);
|
|
extern void nfs_clear_page_tag_locked(struct nfs_page *req);
|
|
|
|
|
|
/*
|
|
* Lock the page of an asynchronous request without getting a new reference
|
|
*/
|
|
static inline int
|
|
nfs_lock_request_dontget(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_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(struct nfs_page *req)
|
|
{
|
|
return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
|
|
}
|
|
|
|
#endif /* _LINUX_NFS_PAGE_H */
|