#ifndef _LINUX_PAGEMAP_H
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#ifndef _LINUX_PAGEMAP_H
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#define _LINUX_PAGEMAP_H
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#define _LINUX_PAGEMAP_H
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#include <asm/system.h>
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#include <asm/system.h>
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/*
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/*
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* Page-mapping primitive inline functions
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* Page-mapping primitive inline functions
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*
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*
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* Copyright 1995 Linus Torvalds
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* Copyright 1995 Linus Torvalds
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*/
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*/
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#include <linux/config.h>
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/fs.h>
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#include <linux/swapctl.h>
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#include <linux/swapctl.h>
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static inline unsigned long page_address(struct page * page)
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static inline unsigned long page_address(struct page * page)
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{
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{
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return PAGE_OFFSET + PAGE_SIZE * page->map_nr;
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return PAGE_OFFSET + PAGE_SIZE * page->map_nr;
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}
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}
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#ifdef CONFIG_REDUCED_MEMORY
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#ifdef CONFIG_REDUCED_MEMORY
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#define PAGE_HASH_BITS 6 /* originally 11 = 8192, 6 = 256 */
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#define PAGE_HASH_BITS 6 /* originally 11 = 8192, 6 = 256 */
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#else /* !CONFIG_REDUCED_MEMORY */
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#else /* !CONFIG_REDUCED_MEMORY */
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#define PAGE_HASH_BITS 11
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#define PAGE_HASH_BITS 11
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#endif /* !CONFIG_REDUCED_MEMORY */
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#endif /* !CONFIG_REDUCED_MEMORY */
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#define PAGE_HASH_SIZE (1 << PAGE_HASH_BITS)
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#define PAGE_HASH_SIZE (1 << PAGE_HASH_BITS)
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#define PAGE_AGE_VALUE ((PAGE_INITIAL_AGE)+(PAGE_ADVANCE))
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#define PAGE_AGE_VALUE ((PAGE_INITIAL_AGE)+(PAGE_ADVANCE))
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extern unsigned long page_cache_size; /* # of pages currently in the hash table */
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extern unsigned long page_cache_size; /* # of pages currently in the hash table */
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extern struct page * page_hash_table[PAGE_HASH_SIZE];
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extern struct page * page_hash_table[PAGE_HASH_SIZE];
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/*
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/*
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* We use a power-of-two hash table to avoid a modulus,
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* We use a power-of-two hash table to avoid a modulus,
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* and get a reasonable hash by knowing roughly how the
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* and get a reasonable hash by knowing roughly how the
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* inode pointer and offsets are distributed (ie, we
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* inode pointer and offsets are distributed (ie, we
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* roughly know which bits are "significant")
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* roughly know which bits are "significant")
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*/
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*/
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static inline unsigned long _page_hashfn(struct inode * inode, unsigned long offset)
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static inline unsigned long _page_hashfn(struct inode * inode, unsigned long offset)
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{
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{
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#define i (((unsigned long) inode)/(sizeof(struct inode) & ~ (sizeof(struct inode) - 1)))
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#define i (((unsigned long) inode)/(sizeof(struct inode) & ~ (sizeof(struct inode) - 1)))
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#define o (offset >> PAGE_SHIFT)
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#define o (offset >> PAGE_SHIFT)
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#define s(x) ((x)+((x)>>PAGE_HASH_BITS))
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#define s(x) ((x)+((x)>>PAGE_HASH_BITS))
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return s(i+o) & (PAGE_HASH_SIZE-1);
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return s(i+o) & (PAGE_HASH_SIZE-1);
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#undef i
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#undef i
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#undef o
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#undef o
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#undef s
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#undef s
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}
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}
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#define page_hash(inode,offset) (page_hash_table+_page_hashfn(inode,offset))
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#define page_hash(inode,offset) (page_hash_table+_page_hashfn(inode,offset))
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static inline struct page * __find_page(struct inode * inode, unsigned long offset, struct page *page)
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static inline struct page * __find_page(struct inode * inode, unsigned long offset, struct page *page)
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{
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{
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goto inside;
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goto inside;
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for (;;) {
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for (;;) {
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page = page->next_hash;
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page = page->next_hash;
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inside:
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inside:
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if (!page)
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if (!page)
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goto not_found;
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goto not_found;
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if (page->inode != inode)
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if (page->inode != inode)
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continue;
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continue;
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if (page->offset == offset)
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if (page->offset == offset)
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break;
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break;
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}
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}
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/* Found the page. */
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/* Found the page. */
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atomic_inc(&page->count);
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atomic_inc(&page->count);
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set_bit(PG_referenced, &page->flags);
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set_bit(PG_referenced, &page->flags);
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not_found:
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not_found:
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return page;
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return page;
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}
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}
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static inline struct page *find_page(struct inode * inode, unsigned long offset)
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static inline struct page *find_page(struct inode * inode, unsigned long offset)
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{
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{
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return __find_page(inode, offset, *page_hash(inode, offset));
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return __find_page(inode, offset, *page_hash(inode, offset));
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}
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}
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static inline void remove_page_from_hash_queue(struct page * page)
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static inline void remove_page_from_hash_queue(struct page * page)
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{
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{
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struct page **p;
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struct page **p;
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struct page *next_hash, *prev_hash;
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struct page *next_hash, *prev_hash;
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next_hash = page->next_hash;
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next_hash = page->next_hash;
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prev_hash = page->prev_hash;
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prev_hash = page->prev_hash;
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page->next_hash = NULL;
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page->next_hash = NULL;
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page->prev_hash = NULL;
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page->prev_hash = NULL;
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if (next_hash)
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if (next_hash)
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next_hash->prev_hash = prev_hash;
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next_hash->prev_hash = prev_hash;
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if (prev_hash)
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if (prev_hash)
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prev_hash->next_hash = next_hash;
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prev_hash->next_hash = next_hash;
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p = page_hash(page->inode,page->offset);
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p = page_hash(page->inode,page->offset);
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if (*p == page)
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if (*p == page)
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*p = next_hash;
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*p = next_hash;
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page_cache_size--;
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page_cache_size--;
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}
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}
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static inline void __add_page_to_hash_queue(struct page * page, struct page **p)
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static inline void __add_page_to_hash_queue(struct page * page, struct page **p)
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{
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{
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page_cache_size++;
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page_cache_size++;
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set_bit(PG_referenced, &page->flags);
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set_bit(PG_referenced, &page->flags);
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page->age = PAGE_AGE_VALUE;
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page->age = PAGE_AGE_VALUE;
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page->prev_hash = NULL;
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page->prev_hash = NULL;
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if ((page->next_hash = *p) != NULL)
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if ((page->next_hash = *p) != NULL)
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page->next_hash->prev_hash = page;
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page->next_hash->prev_hash = page;
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*p = page;
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*p = page;
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}
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}
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static inline void add_page_to_hash_queue(struct page * page, struct inode * inode, unsigned long offset)
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static inline void add_page_to_hash_queue(struct page * page, struct inode * inode, unsigned long offset)
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{
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{
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__add_page_to_hash_queue(page, page_hash(inode,offset));
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__add_page_to_hash_queue(page, page_hash(inode,offset));
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}
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}
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static inline void remove_page_from_inode_queue(struct page * page)
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static inline void remove_page_from_inode_queue(struct page * page)
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{
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{
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struct inode * inode = page->inode;
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struct inode * inode = page->inode;
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page->inode = NULL;
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page->inode = NULL;
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inode->i_nrpages--;
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inode->i_nrpages--;
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if (inode->i_pages == page)
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if (inode->i_pages == page)
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inode->i_pages = page->next;
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inode->i_pages = page->next;
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if (page->next)
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if (page->next)
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page->next->prev = page->prev;
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page->next->prev = page->prev;
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if (page->prev)
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if (page->prev)
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page->prev->next = page->next;
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page->prev->next = page->next;
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page->next = NULL;
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page->next = NULL;
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page->prev = NULL;
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page->prev = NULL;
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}
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}
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static inline void add_page_to_inode_queue(struct inode * inode, struct page * page)
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static inline void add_page_to_inode_queue(struct inode * inode, struct page * page)
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{
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{
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struct page **p = &inode->i_pages;
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struct page **p = &inode->i_pages;
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inode->i_nrpages++;
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inode->i_nrpages++;
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page->inode = inode;
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page->inode = inode;
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page->prev = NULL;
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page->prev = NULL;
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if ((page->next = *p) != NULL)
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if ((page->next = *p) != NULL)
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page->next->prev = page;
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page->next->prev = page;
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*p = page;
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*p = page;
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}
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}
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extern void __wait_on_page(struct page *);
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extern void __wait_on_page(struct page *);
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static inline void wait_on_page(struct page * page)
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static inline void wait_on_page(struct page * page)
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{
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{
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if (PageLocked(page))
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if (PageLocked(page))
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__wait_on_page(page);
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__wait_on_page(page);
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}
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}
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extern void update_vm_cache(struct inode *, unsigned long, const char *, int);
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extern void update_vm_cache(struct inode *, unsigned long, const char *, int);
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#endif
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#endif
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