| /* |
| * 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, |
| PG_MAPPED, |
| PG_CLEAN, |
| PG_NEED_COMMIT, |
| PG_NEED_RESCHED, |
| PG_COMMIT_TO_DS, |
| }; |
| |
| struct nfs_inode; |
| struct nfs_page { |
| struct list_head wb_list; /* Defines state of page: */ |
| 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 nfs_pageio_ops { |
| void (*pg_init)(struct nfs_pageio_descriptor *, struct nfs_page *); |
| bool (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *); |
| int (*pg_doio)(struct nfs_pageio_descriptor *); |
| }; |
| |
| 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; |
| unsigned char pg_moreio : 1, |
| pg_recoalesce : 1; |
| |
| struct inode *pg_inode; |
| const struct nfs_pageio_ops *pg_ops; |
| int pg_ioflags; |
| int pg_error; |
| const struct rpc_call_ops *pg_rpc_callops; |
| struct pnfs_layout_segment *pg_lseg; |
| }; |
| |
| #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_release_request(struct nfs_page *req); |
| |
| |
| extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc, |
| struct inode *inode, |
| const struct nfs_pageio_ops *pg_ops, |
| 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 bool 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); |
| |
| /* |
| * 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); |
| } |
| |
| static inline int |
| nfs_lock_request(struct nfs_page *req) |
| { |
| if (test_and_set_bit(PG_BUSY, &req->wb_flags)) |
| return 0; |
| kref_get(&req->wb_kref); |
| return 1; |
| } |
| |
| |
| /** |
| * 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 */ |