/* * 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, PG_PARTIAL_READ_FAILED, }; 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 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 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, 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); 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 */