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4d65c520fb
Now that the inode scalability patches have been merged, it is no longer safe to call igrab() under the inode->i_lock. Now that we no longer call nfs_clear_request() until the nfs_page is being freed, we know that we are always holding a reference to the nfs_open_context, which again holds a reference to the path, and so the inode cannot be freed until the last nfs_page has been removed from the radix tree and freed. We can therefore skip the igrab()/iput() altogether. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/*
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* linux/include/linux/nfs_page.h
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*
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* Copyright (C) 2000 Trond Myklebust
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*
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* NFS page cache wrapper.
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*/
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#ifndef _LINUX_NFS_PAGE_H
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#define _LINUX_NFS_PAGE_H
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#include <linux/list.h>
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#include <linux/pagemap.h>
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#include <linux/wait.h>
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#include <linux/sunrpc/auth.h>
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#include <linux/nfs_xdr.h>
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#include <linux/kref.h>
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/*
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* Valid flags for the radix tree
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*/
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#define NFS_PAGE_TAG_LOCKED 0
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#define NFS_PAGE_TAG_COMMIT 1
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/*
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* Valid flags for a dirty buffer
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*/
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enum {
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PG_BUSY = 0,
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PG_MAPPED,
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PG_CLEAN,
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PG_NEED_COMMIT,
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PG_NEED_RESCHED,
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PG_PNFS_COMMIT,
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};
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struct nfs_inode;
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struct nfs_page {
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union {
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struct list_head wb_list; /* Defines state of page: */
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struct pnfs_layout_segment *wb_commit_lseg; /* Used when PG_PNFS_COMMIT set */
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};
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struct page *wb_page; /* page to read in/write out */
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struct nfs_open_context *wb_context; /* File state context info */
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struct nfs_lock_context *wb_lock_context; /* lock context info */
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atomic_t wb_complete; /* i/os we're waiting for */
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pgoff_t wb_index; /* Offset >> PAGE_CACHE_SHIFT */
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unsigned int wb_offset, /* Offset & ~PAGE_CACHE_MASK */
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wb_pgbase, /* Start of page data */
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wb_bytes; /* Length of request */
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struct kref wb_kref; /* reference count */
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unsigned long wb_flags;
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struct nfs_writeverf wb_verf; /* Commit cookie */
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};
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struct nfs_pageio_descriptor {
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struct list_head pg_list;
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unsigned long pg_bytes_written;
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size_t pg_count;
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size_t pg_bsize;
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unsigned int pg_base;
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char pg_moreio;
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struct inode *pg_inode;
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int (*pg_doio)(struct nfs_pageio_descriptor *);
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int pg_ioflags;
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int pg_error;
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struct pnfs_layout_segment *pg_lseg;
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int (*pg_test)(struct nfs_pageio_descriptor *, struct nfs_page *, struct nfs_page *);
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};
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#define NFS_WBACK_BUSY(req) (test_bit(PG_BUSY,&(req)->wb_flags))
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extern struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
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struct inode *inode,
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struct page *page,
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unsigned int offset,
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unsigned int count);
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extern void nfs_release_request(struct nfs_page *req);
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extern int nfs_scan_list(struct nfs_inode *nfsi, struct list_head *dst,
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pgoff_t idx_start, unsigned int npages, int tag);
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extern void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
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struct inode *inode,
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int (*doio)(struct nfs_pageio_descriptor *desc),
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size_t bsize,
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int how);
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extern int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
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struct nfs_page *);
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extern void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
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extern void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
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extern int nfs_wait_on_request(struct nfs_page *);
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extern void nfs_unlock_request(struct nfs_page *req);
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extern int nfs_set_page_tag_locked(struct nfs_page *req);
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extern void nfs_clear_page_tag_locked(struct nfs_page *req);
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/*
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* Lock the page of an asynchronous request without getting a new reference
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*/
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static inline int
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nfs_lock_request_dontget(struct nfs_page *req)
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{
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return !test_and_set_bit(PG_BUSY, &req->wb_flags);
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}
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/**
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* nfs_list_add_request - Insert a request into a list
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* @req: request
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* @head: head of list into which to insert the request.
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*/
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static inline void
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nfs_list_add_request(struct nfs_page *req, struct list_head *head)
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{
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list_add_tail(&req->wb_list, head);
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}
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/**
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* nfs_list_remove_request - Remove a request from its wb_list
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* @req: request
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*/
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static inline void
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nfs_list_remove_request(struct nfs_page *req)
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{
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if (list_empty(&req->wb_list))
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return;
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list_del_init(&req->wb_list);
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}
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static inline struct nfs_page *
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nfs_list_entry(struct list_head *head)
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{
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return list_entry(head, struct nfs_page, wb_list);
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}
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static inline
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loff_t req_offset(struct nfs_page *req)
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{
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return (((loff_t)req->wb_index) << PAGE_CACHE_SHIFT) + req->wb_offset;
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}
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#endif /* _LINUX_NFS_PAGE_H */
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