1308 lines
38 KiB
C
1308 lines
38 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_PAGEMAP_H
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#define _LINUX_PAGEMAP_H
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/*
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* Copyright 1995 Linus Torvalds
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*/
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/list.h>
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#include <linux/highmem.h>
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#include <linux/compiler.h>
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#include <linux/uaccess.h>
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#include <linux/gfp.h>
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#include <linux/bitops.h>
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#include <linux/hardirq.h> /* for in_interrupt() */
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#include <linux/hugetlb_inline.h>
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struct folio_batch;
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static inline bool mapping_empty(struct address_space *mapping)
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{
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return xa_empty(&mapping->i_pages);
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}
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/*
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* mapping_shrinkable - test if page cache state allows inode reclaim
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* @mapping: the page cache mapping
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*
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* This checks the mapping's cache state for the pupose of inode
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* reclaim and LRU management.
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*
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* The caller is expected to hold the i_lock, but is not required to
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* hold the i_pages lock, which usually protects cache state. That's
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* because the i_lock and the list_lru lock that protect the inode and
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* its LRU state don't nest inside the irq-safe i_pages lock.
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*
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* Cache deletions are performed under the i_lock, which ensures that
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* when an inode goes empty, it will reliably get queued on the LRU.
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*
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* Cache additions do not acquire the i_lock and may race with this
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* check, in which case we'll report the inode as shrinkable when it
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* has cache pages. This is okay: the shrinker also checks the
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* refcount and the referenced bit, which will be elevated or set in
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* the process of adding new cache pages to an inode.
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*/
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static inline bool mapping_shrinkable(struct address_space *mapping)
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{
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void *head;
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/*
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* On highmem systems, there could be lowmem pressure from the
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* inodes before there is highmem pressure from the page
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* cache. Make inodes shrinkable regardless of cache state.
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*/
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if (IS_ENABLED(CONFIG_HIGHMEM))
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return true;
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/* Cache completely empty? Shrink away. */
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head = rcu_access_pointer(mapping->i_pages.xa_head);
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if (!head)
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return true;
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/*
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* The xarray stores single offset-0 entries directly in the
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* head pointer, which allows non-resident page cache entries
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* to escape the shadow shrinker's list of xarray nodes. The
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* inode shrinker needs to pick them up under memory pressure.
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*/
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if (!xa_is_node(head) && xa_is_value(head))
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return true;
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return false;
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}
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/*
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* Bits in mapping->flags.
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*/
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enum mapping_flags {
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AS_EIO = 0, /* IO error on async write */
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AS_ENOSPC = 1, /* ENOSPC on async write */
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AS_MM_ALL_LOCKS = 2, /* under mm_take_all_locks() */
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AS_UNEVICTABLE = 3, /* e.g., ramdisk, SHM_LOCK */
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AS_EXITING = 4, /* final truncate in progress */
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/* writeback related tags are not used */
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AS_NO_WRITEBACK_TAGS = 5,
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AS_LARGE_FOLIO_SUPPORT = 6,
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};
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/**
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* mapping_set_error - record a writeback error in the address_space
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* @mapping: the mapping in which an error should be set
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* @error: the error to set in the mapping
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*
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* When writeback fails in some way, we must record that error so that
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* userspace can be informed when fsync and the like are called. We endeavor
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* to report errors on any file that was open at the time of the error. Some
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* internal callers also need to know when writeback errors have occurred.
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*
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* When a writeback error occurs, most filesystems will want to call
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* mapping_set_error to record the error in the mapping so that it can be
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* reported when the application calls fsync(2).
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*/
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static inline void mapping_set_error(struct address_space *mapping, int error)
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{
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if (likely(!error))
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return;
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/* Record in wb_err for checkers using errseq_t based tracking */
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__filemap_set_wb_err(mapping, error);
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/* Record it in superblock */
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if (mapping->host)
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errseq_set(&mapping->host->i_sb->s_wb_err, error);
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/* Record it in flags for now, for legacy callers */
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if (error == -ENOSPC)
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set_bit(AS_ENOSPC, &mapping->flags);
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else
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set_bit(AS_EIO, &mapping->flags);
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}
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static inline void mapping_set_unevictable(struct address_space *mapping)
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{
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set_bit(AS_UNEVICTABLE, &mapping->flags);
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}
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static inline void mapping_clear_unevictable(struct address_space *mapping)
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{
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clear_bit(AS_UNEVICTABLE, &mapping->flags);
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}
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static inline bool mapping_unevictable(struct address_space *mapping)
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{
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return mapping && test_bit(AS_UNEVICTABLE, &mapping->flags);
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}
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static inline void mapping_set_exiting(struct address_space *mapping)
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{
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set_bit(AS_EXITING, &mapping->flags);
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}
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static inline int mapping_exiting(struct address_space *mapping)
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{
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return test_bit(AS_EXITING, &mapping->flags);
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}
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static inline void mapping_set_no_writeback_tags(struct address_space *mapping)
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{
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set_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
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}
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static inline int mapping_use_writeback_tags(struct address_space *mapping)
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{
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return !test_bit(AS_NO_WRITEBACK_TAGS, &mapping->flags);
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}
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static inline gfp_t mapping_gfp_mask(struct address_space * mapping)
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{
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return mapping->gfp_mask;
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}
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/* Restricts the given gfp_mask to what the mapping allows. */
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static inline gfp_t mapping_gfp_constraint(struct address_space *mapping,
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gfp_t gfp_mask)
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{
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return mapping_gfp_mask(mapping) & gfp_mask;
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}
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/*
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* This is non-atomic. Only to be used before the mapping is activated.
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* Probably needs a barrier...
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*/
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static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
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{
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m->gfp_mask = mask;
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}
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/**
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* mapping_set_large_folios() - Indicate the file supports large folios.
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* @mapping: The file.
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*
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* The filesystem should call this function in its inode constructor to
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* indicate that the VFS can use large folios to cache the contents of
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* the file.
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*
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* Context: This should not be called while the inode is active as it
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* is non-atomic.
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*/
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static inline void mapping_set_large_folios(struct address_space *mapping)
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{
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__set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
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}
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static inline bool mapping_large_folio_support(struct address_space *mapping)
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{
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return test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);
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}
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static inline int filemap_nr_thps(struct address_space *mapping)
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{
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#ifdef CONFIG_READ_ONLY_THP_FOR_FS
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return atomic_read(&mapping->nr_thps);
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#else
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return 0;
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#endif
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}
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static inline void filemap_nr_thps_inc(struct address_space *mapping)
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{
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#ifdef CONFIG_READ_ONLY_THP_FOR_FS
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if (!mapping_large_folio_support(mapping))
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atomic_inc(&mapping->nr_thps);
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#else
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WARN_ON_ONCE(1);
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#endif
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}
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static inline void filemap_nr_thps_dec(struct address_space *mapping)
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{
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#ifdef CONFIG_READ_ONLY_THP_FOR_FS
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if (!mapping_large_folio_support(mapping))
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atomic_dec(&mapping->nr_thps);
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#else
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WARN_ON_ONCE(1);
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#endif
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}
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void release_pages(struct page **pages, int nr);
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struct address_space *page_mapping(struct page *);
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struct address_space *folio_mapping(struct folio *);
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struct address_space *swapcache_mapping(struct folio *);
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/**
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* folio_file_mapping - Find the mapping this folio belongs to.
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* @folio: The folio.
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*
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* For folios which are in the page cache, return the mapping that this
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* page belongs to. Folios in the swap cache return the mapping of the
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* swap file or swap device where the data is stored. This is different
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* from the mapping returned by folio_mapping(). The only reason to
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* use it is if, like NFS, you return 0 from ->activate_swapfile.
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*
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* Do not call this for folios which aren't in the page cache or swap cache.
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*/
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static inline struct address_space *folio_file_mapping(struct folio *folio)
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{
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if (unlikely(folio_test_swapcache(folio)))
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return swapcache_mapping(folio);
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return folio->mapping;
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}
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static inline struct address_space *page_file_mapping(struct page *page)
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{
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return folio_file_mapping(page_folio(page));
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}
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/*
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* For file cache pages, return the address_space, otherwise return NULL
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*/
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static inline struct address_space *page_mapping_file(struct page *page)
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{
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struct folio *folio = page_folio(page);
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if (unlikely(folio_test_swapcache(folio)))
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return NULL;
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return folio_mapping(folio);
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}
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/**
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* folio_inode - Get the host inode for this folio.
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* @folio: The folio.
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*
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* For folios which are in the page cache, return the inode that this folio
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* belongs to.
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*
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* Do not call this for folios which aren't in the page cache.
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*/
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static inline struct inode *folio_inode(struct folio *folio)
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{
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return folio->mapping->host;
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}
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static inline bool page_cache_add_speculative(struct page *page, int count)
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{
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return folio_ref_try_add_rcu((struct folio *)page, count);
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}
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static inline bool page_cache_get_speculative(struct page *page)
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{
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return page_cache_add_speculative(page, 1);
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}
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/**
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* folio_attach_private - Attach private data to a folio.
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* @folio: Folio to attach data to.
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* @data: Data to attach to folio.
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*
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* Attaching private data to a folio increments the page's reference count.
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* The data must be detached before the folio will be freed.
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*/
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static inline void folio_attach_private(struct folio *folio, void *data)
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{
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folio_get(folio);
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folio->private = data;
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folio_set_private(folio);
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}
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/**
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* folio_change_private - Change private data on a folio.
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* @folio: Folio to change the data on.
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* @data: Data to set on the folio.
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*
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* Change the private data attached to a folio and return the old
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* data. The page must previously have had data attached and the data
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* must be detached before the folio will be freed.
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*
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* Return: Data that was previously attached to the folio.
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*/
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static inline void *folio_change_private(struct folio *folio, void *data)
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{
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void *old = folio_get_private(folio);
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folio->private = data;
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return old;
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}
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/**
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* folio_detach_private - Detach private data from a folio.
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* @folio: Folio to detach data from.
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*
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* Removes the data that was previously attached to the folio and decrements
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* the refcount on the page.
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*
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* Return: Data that was attached to the folio.
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*/
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static inline void *folio_detach_private(struct folio *folio)
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{
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void *data = folio_get_private(folio);
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if (!folio_test_private(folio))
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return NULL;
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folio_clear_private(folio);
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folio->private = NULL;
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folio_put(folio);
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return data;
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}
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static inline void attach_page_private(struct page *page, void *data)
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{
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folio_attach_private(page_folio(page), data);
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}
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static inline void *detach_page_private(struct page *page)
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{
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return folio_detach_private(page_folio(page));
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}
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#ifdef CONFIG_NUMA
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struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order);
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#else
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static inline struct folio *filemap_alloc_folio(gfp_t gfp, unsigned int order)
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{
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return folio_alloc(gfp, order);
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}
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#endif
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static inline struct page *__page_cache_alloc(gfp_t gfp)
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{
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return &filemap_alloc_folio(gfp, 0)->page;
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}
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static inline struct page *page_cache_alloc(struct address_space *x)
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{
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return __page_cache_alloc(mapping_gfp_mask(x));
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}
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static inline gfp_t readahead_gfp_mask(struct address_space *x)
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{
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return mapping_gfp_mask(x) | __GFP_NORETRY | __GFP_NOWARN;
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}
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typedef int filler_t(void *, struct page *);
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pgoff_t page_cache_next_miss(struct address_space *mapping,
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pgoff_t index, unsigned long max_scan);
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pgoff_t page_cache_prev_miss(struct address_space *mapping,
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pgoff_t index, unsigned long max_scan);
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#define FGP_ACCESSED 0x00000001
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#define FGP_LOCK 0x00000002
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#define FGP_CREAT 0x00000004
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#define FGP_WRITE 0x00000008
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#define FGP_NOFS 0x00000010
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#define FGP_NOWAIT 0x00000020
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#define FGP_FOR_MMAP 0x00000040
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#define FGP_HEAD 0x00000080
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#define FGP_ENTRY 0x00000100
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#define FGP_STABLE 0x00000200
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struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
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int fgp_flags, gfp_t gfp);
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struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
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int fgp_flags, gfp_t gfp);
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/**
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* filemap_get_folio - Find and get a folio.
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* @mapping: The address_space to search.
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* @index: The page index.
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*
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* Looks up the page cache entry at @mapping & @index. If a folio is
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* present, it is returned with an increased refcount.
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*
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* Otherwise, %NULL is returned.
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*/
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static inline struct folio *filemap_get_folio(struct address_space *mapping,
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pgoff_t index)
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{
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return __filemap_get_folio(mapping, index, 0, 0);
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}
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/**
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* find_get_page - find and get a page reference
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* @mapping: the address_space to search
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* @offset: the page index
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned with an increased refcount.
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*
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* Otherwise, %NULL is returned.
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*/
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static inline struct page *find_get_page(struct address_space *mapping,
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pgoff_t offset)
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{
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return pagecache_get_page(mapping, offset, 0, 0);
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}
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static inline struct page *find_get_page_flags(struct address_space *mapping,
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pgoff_t offset, int fgp_flags)
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{
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return pagecache_get_page(mapping, offset, fgp_flags, 0);
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}
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/**
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* find_lock_page - locate, pin and lock a pagecache page
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* @mapping: the address_space to search
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* @index: the page index
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*
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* Looks up the page cache entry at @mapping & @index. If there is a
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* page cache page, it is returned locked and with an increased
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* refcount.
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*
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* Context: May sleep.
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* Return: A struct page or %NULL if there is no page in the cache for this
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* index.
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*/
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static inline struct page *find_lock_page(struct address_space *mapping,
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pgoff_t index)
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{
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return pagecache_get_page(mapping, index, FGP_LOCK, 0);
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}
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/**
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* find_or_create_page - locate or add a pagecache page
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* @mapping: the page's address_space
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* @index: the page's index into the mapping
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* @gfp_mask: page allocation mode
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned locked and with an increased
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* refcount.
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*
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* If the page is not present, a new page is allocated using @gfp_mask
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* and added to the page cache and the VM's LRU list. The page is
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* returned locked and with an increased refcount.
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*
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* On memory exhaustion, %NULL is returned.
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*
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* find_or_create_page() may sleep, even if @gfp_flags specifies an
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* atomic allocation!
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*/
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static inline struct page *find_or_create_page(struct address_space *mapping,
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pgoff_t index, gfp_t gfp_mask)
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{
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return pagecache_get_page(mapping, index,
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FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
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gfp_mask);
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}
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/**
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* grab_cache_page_nowait - returns locked page at given index in given cache
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* @mapping: target address_space
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* @index: the page index
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*
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* Same as grab_cache_page(), but do not wait if the page is unavailable.
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* This is intended for speculative data generators, where the data can
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* be regenerated if the page couldn't be grabbed. This routine should
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* be safe to call while holding the lock for another page.
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*
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* Clear __GFP_FS when allocating the page to avoid recursion into the fs
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* and deadlock against the caller's locked page.
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*/
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static inline struct page *grab_cache_page_nowait(struct address_space *mapping,
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pgoff_t index)
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{
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return pagecache_get_page(mapping, index,
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FGP_LOCK|FGP_CREAT|FGP_NOFS|FGP_NOWAIT,
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mapping_gfp_mask(mapping));
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}
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#define swapcache_index(folio) __page_file_index(&(folio)->page)
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/**
|
|
* folio_index - File index of a folio.
|
|
* @folio: The folio.
|
|
*
|
|
* For a folio which is either in the page cache or the swap cache,
|
|
* return its index within the address_space it belongs to. If you know
|
|
* the page is definitely in the page cache, you can look at the folio's
|
|
* index directly.
|
|
*
|
|
* Return: The index (offset in units of pages) of a folio in its file.
|
|
*/
|
|
static inline pgoff_t folio_index(struct folio *folio)
|
|
{
|
|
if (unlikely(folio_test_swapcache(folio)))
|
|
return swapcache_index(folio);
|
|
return folio->index;
|
|
}
|
|
|
|
/**
|
|
* folio_next_index - Get the index of the next folio.
|
|
* @folio: The current folio.
|
|
*
|
|
* Return: The index of the folio which follows this folio in the file.
|
|
*/
|
|
static inline pgoff_t folio_next_index(struct folio *folio)
|
|
{
|
|
return folio->index + folio_nr_pages(folio);
|
|
}
|
|
|
|
/**
|
|
* folio_file_page - The page for a particular index.
|
|
* @folio: The folio which contains this index.
|
|
* @index: The index we want to look up.
|
|
*
|
|
* Sometimes after looking up a folio in the page cache, we need to
|
|
* obtain the specific page for an index (eg a page fault).
|
|
*
|
|
* Return: The page containing the file data for this index.
|
|
*/
|
|
static inline struct page *folio_file_page(struct folio *folio, pgoff_t index)
|
|
{
|
|
/* HugeTLBfs indexes the page cache in units of hpage_size */
|
|
if (folio_test_hugetlb(folio))
|
|
return &folio->page;
|
|
return folio_page(folio, index & (folio_nr_pages(folio) - 1));
|
|
}
|
|
|
|
/**
|
|
* folio_contains - Does this folio contain this index?
|
|
* @folio: The folio.
|
|
* @index: The page index within the file.
|
|
*
|
|
* Context: The caller should have the page locked in order to prevent
|
|
* (eg) shmem from moving the page between the page cache and swap cache
|
|
* and changing its index in the middle of the operation.
|
|
* Return: true or false.
|
|
*/
|
|
static inline bool folio_contains(struct folio *folio, pgoff_t index)
|
|
{
|
|
/* HugeTLBfs indexes the page cache in units of hpage_size */
|
|
if (folio_test_hugetlb(folio))
|
|
return folio->index == index;
|
|
return index - folio_index(folio) < folio_nr_pages(folio);
|
|
}
|
|
|
|
/*
|
|
* Given the page we found in the page cache, return the page corresponding
|
|
* to this index in the file
|
|
*/
|
|
static inline struct page *find_subpage(struct page *head, pgoff_t index)
|
|
{
|
|
/* HugeTLBfs wants the head page regardless */
|
|
if (PageHuge(head))
|
|
return head;
|
|
|
|
return head + (index & (thp_nr_pages(head) - 1));
|
|
}
|
|
|
|
unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
|
|
pgoff_t end, unsigned int nr_pages,
|
|
struct page **pages);
|
|
static inline unsigned find_get_pages(struct address_space *mapping,
|
|
pgoff_t *start, unsigned int nr_pages,
|
|
struct page **pages)
|
|
{
|
|
return find_get_pages_range(mapping, start, (pgoff_t)-1, nr_pages,
|
|
pages);
|
|
}
|
|
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
|
|
unsigned int nr_pages, struct page **pages);
|
|
unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
|
|
pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
|
|
struct page **pages);
|
|
static inline unsigned find_get_pages_tag(struct address_space *mapping,
|
|
pgoff_t *index, xa_mark_t tag, unsigned int nr_pages,
|
|
struct page **pages)
|
|
{
|
|
return find_get_pages_range_tag(mapping, index, (pgoff_t)-1, tag,
|
|
nr_pages, pages);
|
|
}
|
|
|
|
struct page *grab_cache_page_write_begin(struct address_space *mapping,
|
|
pgoff_t index, unsigned flags);
|
|
|
|
/*
|
|
* Returns locked page at given index in given cache, creating it if needed.
|
|
*/
|
|
static inline struct page *grab_cache_page(struct address_space *mapping,
|
|
pgoff_t index)
|
|
{
|
|
return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
|
|
}
|
|
|
|
struct folio *read_cache_folio(struct address_space *, pgoff_t index,
|
|
filler_t *filler, void *data);
|
|
struct page *read_cache_page(struct address_space *, pgoff_t index,
|
|
filler_t *filler, void *data);
|
|
extern struct page * read_cache_page_gfp(struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp_mask);
|
|
extern int read_cache_pages(struct address_space *mapping,
|
|
struct list_head *pages, filler_t *filler, void *data);
|
|
|
|
static inline struct page *read_mapping_page(struct address_space *mapping,
|
|
pgoff_t index, void *data)
|
|
{
|
|
return read_cache_page(mapping, index, NULL, data);
|
|
}
|
|
|
|
static inline struct folio *read_mapping_folio(struct address_space *mapping,
|
|
pgoff_t index, void *data)
|
|
{
|
|
return read_cache_folio(mapping, index, NULL, data);
|
|
}
|
|
|
|
/*
|
|
* Get index of the page within radix-tree (but not for hugetlb pages).
|
|
* (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE)
|
|
*/
|
|
static inline pgoff_t page_to_index(struct page *page)
|
|
{
|
|
struct page *head;
|
|
|
|
if (likely(!PageTransTail(page)))
|
|
return page->index;
|
|
|
|
head = compound_head(page);
|
|
/*
|
|
* We don't initialize ->index for tail pages: calculate based on
|
|
* head page
|
|
*/
|
|
return head->index + page - head;
|
|
}
|
|
|
|
extern pgoff_t hugetlb_basepage_index(struct page *page);
|
|
|
|
/*
|
|
* Get the offset in PAGE_SIZE (even for hugetlb pages).
|
|
* (TODO: hugetlb pages should have ->index in PAGE_SIZE)
|
|
*/
|
|
static inline pgoff_t page_to_pgoff(struct page *page)
|
|
{
|
|
if (unlikely(PageHuge(page)))
|
|
return hugetlb_basepage_index(page);
|
|
return page_to_index(page);
|
|
}
|
|
|
|
/*
|
|
* Return byte-offset into filesystem object for page.
|
|
*/
|
|
static inline loff_t page_offset(struct page *page)
|
|
{
|
|
return ((loff_t)page->index) << PAGE_SHIFT;
|
|
}
|
|
|
|
static inline loff_t page_file_offset(struct page *page)
|
|
{
|
|
return ((loff_t)page_index(page)) << PAGE_SHIFT;
|
|
}
|
|
|
|
/**
|
|
* folio_pos - Returns the byte position of this folio in its file.
|
|
* @folio: The folio.
|
|
*/
|
|
static inline loff_t folio_pos(struct folio *folio)
|
|
{
|
|
return page_offset(&folio->page);
|
|
}
|
|
|
|
/**
|
|
* folio_file_pos - Returns the byte position of this folio in its file.
|
|
* @folio: The folio.
|
|
*
|
|
* This differs from folio_pos() for folios which belong to a swap file.
|
|
* NFS is the only filesystem today which needs to use folio_file_pos().
|
|
*/
|
|
static inline loff_t folio_file_pos(struct folio *folio)
|
|
{
|
|
return page_file_offset(&folio->page);
|
|
}
|
|
|
|
extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
|
|
unsigned long address);
|
|
|
|
static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
|
|
unsigned long address)
|
|
{
|
|
pgoff_t pgoff;
|
|
if (unlikely(is_vm_hugetlb_page(vma)))
|
|
return linear_hugepage_index(vma, address);
|
|
pgoff = (address - vma->vm_start) >> PAGE_SHIFT;
|
|
pgoff += vma->vm_pgoff;
|
|
return pgoff;
|
|
}
|
|
|
|
struct wait_page_key {
|
|
struct folio *folio;
|
|
int bit_nr;
|
|
int page_match;
|
|
};
|
|
|
|
struct wait_page_queue {
|
|
struct folio *folio;
|
|
int bit_nr;
|
|
wait_queue_entry_t wait;
|
|
};
|
|
|
|
static inline bool wake_page_match(struct wait_page_queue *wait_page,
|
|
struct wait_page_key *key)
|
|
{
|
|
if (wait_page->folio != key->folio)
|
|
return false;
|
|
key->page_match = 1;
|
|
|
|
if (wait_page->bit_nr != key->bit_nr)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
void __folio_lock(struct folio *folio);
|
|
int __folio_lock_killable(struct folio *folio);
|
|
bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
|
|
unsigned int flags);
|
|
void unlock_page(struct page *page);
|
|
void folio_unlock(struct folio *folio);
|
|
|
|
static inline bool folio_trylock(struct folio *folio)
|
|
{
|
|
return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio, 0)));
|
|
}
|
|
|
|
/*
|
|
* Return true if the page was successfully locked
|
|
*/
|
|
static inline int trylock_page(struct page *page)
|
|
{
|
|
return folio_trylock(page_folio(page));
|
|
}
|
|
|
|
static inline void folio_lock(struct folio *folio)
|
|
{
|
|
might_sleep();
|
|
if (!folio_trylock(folio))
|
|
__folio_lock(folio);
|
|
}
|
|
|
|
/*
|
|
* lock_page may only be called if we have the page's inode pinned.
|
|
*/
|
|
static inline void lock_page(struct page *page)
|
|
{
|
|
struct folio *folio;
|
|
might_sleep();
|
|
|
|
folio = page_folio(page);
|
|
if (!folio_trylock(folio))
|
|
__folio_lock(folio);
|
|
}
|
|
|
|
static inline int folio_lock_killable(struct folio *folio)
|
|
{
|
|
might_sleep();
|
|
if (!folio_trylock(folio))
|
|
return __folio_lock_killable(folio);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* lock_page_killable is like lock_page but can be interrupted by fatal
|
|
* signals. It returns 0 if it locked the page and -EINTR if it was
|
|
* killed while waiting.
|
|
*/
|
|
static inline int lock_page_killable(struct page *page)
|
|
{
|
|
return folio_lock_killable(page_folio(page));
|
|
}
|
|
|
|
/*
|
|
* lock_page_or_retry - Lock the page, unless this would block and the
|
|
* caller indicated that it can handle a retry.
|
|
*
|
|
* Return value and mmap_lock implications depend on flags; see
|
|
* __folio_lock_or_retry().
|
|
*/
|
|
static inline bool lock_page_or_retry(struct page *page, struct mm_struct *mm,
|
|
unsigned int flags)
|
|
{
|
|
struct folio *folio;
|
|
might_sleep();
|
|
|
|
folio = page_folio(page);
|
|
return folio_trylock(folio) || __folio_lock_or_retry(folio, mm, flags);
|
|
}
|
|
|
|
/*
|
|
* This is exported only for folio_wait_locked/folio_wait_writeback, etc.,
|
|
* and should not be used directly.
|
|
*/
|
|
void folio_wait_bit(struct folio *folio, int bit_nr);
|
|
int folio_wait_bit_killable(struct folio *folio, int bit_nr);
|
|
|
|
/*
|
|
* Wait for a folio to be unlocked.
|
|
*
|
|
* This must be called with the caller "holding" the folio,
|
|
* ie with increased "page->count" so that the folio won't
|
|
* go away during the wait..
|
|
*/
|
|
static inline void folio_wait_locked(struct folio *folio)
|
|
{
|
|
if (folio_test_locked(folio))
|
|
folio_wait_bit(folio, PG_locked);
|
|
}
|
|
|
|
static inline int folio_wait_locked_killable(struct folio *folio)
|
|
{
|
|
if (!folio_test_locked(folio))
|
|
return 0;
|
|
return folio_wait_bit_killable(folio, PG_locked);
|
|
}
|
|
|
|
static inline void wait_on_page_locked(struct page *page)
|
|
{
|
|
folio_wait_locked(page_folio(page));
|
|
}
|
|
|
|
static inline int wait_on_page_locked_killable(struct page *page)
|
|
{
|
|
return folio_wait_locked_killable(page_folio(page));
|
|
}
|
|
|
|
int folio_put_wait_locked(struct folio *folio, int state);
|
|
void wait_on_page_writeback(struct page *page);
|
|
void folio_wait_writeback(struct folio *folio);
|
|
int folio_wait_writeback_killable(struct folio *folio);
|
|
void end_page_writeback(struct page *page);
|
|
void folio_end_writeback(struct folio *folio);
|
|
void wait_for_stable_page(struct page *page);
|
|
void folio_wait_stable(struct folio *folio);
|
|
void __folio_mark_dirty(struct folio *folio, struct address_space *, int warn);
|
|
static inline void __set_page_dirty(struct page *page,
|
|
struct address_space *mapping, int warn)
|
|
{
|
|
__folio_mark_dirty(page_folio(page), mapping, warn);
|
|
}
|
|
void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
|
|
struct bdi_writeback *wb);
|
|
void __folio_cancel_dirty(struct folio *folio);
|
|
static inline void folio_cancel_dirty(struct folio *folio)
|
|
{
|
|
/* Avoid atomic ops, locking, etc. when not actually needed. */
|
|
if (folio_test_dirty(folio))
|
|
__folio_cancel_dirty(folio);
|
|
}
|
|
static inline void cancel_dirty_page(struct page *page)
|
|
{
|
|
folio_cancel_dirty(page_folio(page));
|
|
}
|
|
bool folio_clear_dirty_for_io(struct folio *folio);
|
|
bool clear_page_dirty_for_io(struct page *page);
|
|
int __must_check folio_write_one(struct folio *folio);
|
|
static inline int __must_check write_one_page(struct page *page)
|
|
{
|
|
return folio_write_one(page_folio(page));
|
|
}
|
|
|
|
int __set_page_dirty_nobuffers(struct page *page);
|
|
int __set_page_dirty_no_writeback(struct page *page);
|
|
|
|
void page_endio(struct page *page, bool is_write, int err);
|
|
|
|
void folio_end_private_2(struct folio *folio);
|
|
void folio_wait_private_2(struct folio *folio);
|
|
int folio_wait_private_2_killable(struct folio *folio);
|
|
|
|
/*
|
|
* Add an arbitrary waiter to a page's wait queue
|
|
*/
|
|
void folio_add_wait_queue(struct folio *folio, wait_queue_entry_t *waiter);
|
|
|
|
/*
|
|
* Fault in userspace address range.
|
|
*/
|
|
size_t fault_in_writeable(char __user *uaddr, size_t size);
|
|
size_t fault_in_safe_writeable(const char __user *uaddr, size_t size);
|
|
size_t fault_in_readable(const char __user *uaddr, size_t size);
|
|
|
|
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp);
|
|
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
|
|
pgoff_t index, gfp_t gfp);
|
|
int filemap_add_folio(struct address_space *mapping, struct folio *folio,
|
|
pgoff_t index, gfp_t gfp);
|
|
void filemap_remove_folio(struct folio *folio);
|
|
void delete_from_page_cache(struct page *page);
|
|
void __filemap_remove_folio(struct folio *folio, void *shadow);
|
|
static inline void __delete_from_page_cache(struct page *page, void *shadow)
|
|
{
|
|
__filemap_remove_folio(page_folio(page), shadow);
|
|
}
|
|
void replace_page_cache_page(struct page *old, struct page *new);
|
|
void delete_from_page_cache_batch(struct address_space *mapping,
|
|
struct folio_batch *fbatch);
|
|
int try_to_release_page(struct page *page, gfp_t gfp);
|
|
bool filemap_release_folio(struct folio *folio, gfp_t gfp);
|
|
loff_t mapping_seek_hole_data(struct address_space *, loff_t start, loff_t end,
|
|
int whence);
|
|
|
|
/*
|
|
* Like add_to_page_cache_locked, but used to add newly allocated pages:
|
|
* the page is new, so we can just run __SetPageLocked() against it.
|
|
*/
|
|
static inline int add_to_page_cache(struct page *page,
|
|
struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
|
|
{
|
|
int error;
|
|
|
|
__SetPageLocked(page);
|
|
error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
|
|
if (unlikely(error))
|
|
__ClearPageLocked(page);
|
|
return error;
|
|
}
|
|
|
|
/* Must be non-static for BPF error injection */
|
|
int __filemap_add_folio(struct address_space *mapping, struct folio *folio,
|
|
pgoff_t index, gfp_t gfp, void **shadowp);
|
|
|
|
bool filemap_range_has_writeback(struct address_space *mapping,
|
|
loff_t start_byte, loff_t end_byte);
|
|
|
|
/**
|
|
* filemap_range_needs_writeback - check if range potentially needs writeback
|
|
* @mapping: address space within which to check
|
|
* @start_byte: offset in bytes where the range starts
|
|
* @end_byte: offset in bytes where the range ends (inclusive)
|
|
*
|
|
* Find at least one page in the range supplied, usually used to check if
|
|
* direct writing in this range will trigger a writeback. Used by O_DIRECT
|
|
* read/write with IOCB_NOWAIT, to see if the caller needs to do
|
|
* filemap_write_and_wait_range() before proceeding.
|
|
*
|
|
* Return: %true if the caller should do filemap_write_and_wait_range() before
|
|
* doing O_DIRECT to a page in this range, %false otherwise.
|
|
*/
|
|
static inline bool filemap_range_needs_writeback(struct address_space *mapping,
|
|
loff_t start_byte,
|
|
loff_t end_byte)
|
|
{
|
|
if (!mapping->nrpages)
|
|
return false;
|
|
if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
|
|
!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
|
|
return false;
|
|
return filemap_range_has_writeback(mapping, start_byte, end_byte);
|
|
}
|
|
|
|
/**
|
|
* struct readahead_control - Describes a readahead request.
|
|
*
|
|
* A readahead request is for consecutive pages. Filesystems which
|
|
* implement the ->readahead method should call readahead_page() or
|
|
* readahead_page_batch() in a loop and attempt to start I/O against
|
|
* each page in the request.
|
|
*
|
|
* Most of the fields in this struct are private and should be accessed
|
|
* by the functions below.
|
|
*
|
|
* @file: The file, used primarily by network filesystems for authentication.
|
|
* May be NULL if invoked internally by the filesystem.
|
|
* @mapping: Readahead this filesystem object.
|
|
* @ra: File readahead state. May be NULL.
|
|
*/
|
|
struct readahead_control {
|
|
struct file *file;
|
|
struct address_space *mapping;
|
|
struct file_ra_state *ra;
|
|
/* private: use the readahead_* accessors instead */
|
|
pgoff_t _index;
|
|
unsigned int _nr_pages;
|
|
unsigned int _batch_count;
|
|
};
|
|
|
|
#define DEFINE_READAHEAD(ractl, f, r, m, i) \
|
|
struct readahead_control ractl = { \
|
|
.file = f, \
|
|
.mapping = m, \
|
|
.ra = r, \
|
|
._index = i, \
|
|
}
|
|
|
|
#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE)
|
|
|
|
void page_cache_ra_unbounded(struct readahead_control *,
|
|
unsigned long nr_to_read, unsigned long lookahead_count);
|
|
void page_cache_sync_ra(struct readahead_control *, unsigned long req_count);
|
|
void page_cache_async_ra(struct readahead_control *, struct folio *,
|
|
unsigned long req_count);
|
|
void readahead_expand(struct readahead_control *ractl,
|
|
loff_t new_start, size_t new_len);
|
|
|
|
/**
|
|
* page_cache_sync_readahead - generic file readahead
|
|
* @mapping: address_space which holds the pagecache and I/O vectors
|
|
* @ra: file_ra_state which holds the readahead state
|
|
* @file: Used by the filesystem for authentication.
|
|
* @index: Index of first page to be read.
|
|
* @req_count: Total number of pages being read by the caller.
|
|
*
|
|
* page_cache_sync_readahead() should be called when a cache miss happened:
|
|
* it will submit the read. The readahead logic may decide to piggyback more
|
|
* pages onto the read request if access patterns suggest it will improve
|
|
* performance.
|
|
*/
|
|
static inline
|
|
void page_cache_sync_readahead(struct address_space *mapping,
|
|
struct file_ra_state *ra, struct file *file, pgoff_t index,
|
|
unsigned long req_count)
|
|
{
|
|
DEFINE_READAHEAD(ractl, file, ra, mapping, index);
|
|
page_cache_sync_ra(&ractl, req_count);
|
|
}
|
|
|
|
/**
|
|
* page_cache_async_readahead - file readahead for marked pages
|
|
* @mapping: address_space which holds the pagecache and I/O vectors
|
|
* @ra: file_ra_state which holds the readahead state
|
|
* @file: Used by the filesystem for authentication.
|
|
* @page: The page at @index which triggered the readahead call.
|
|
* @index: Index of first page to be read.
|
|
* @req_count: Total number of pages being read by the caller.
|
|
*
|
|
* page_cache_async_readahead() should be called when a page is used which
|
|
* is marked as PageReadahead; this is a marker to suggest that the application
|
|
* has used up enough of the readahead window that we should start pulling in
|
|
* more pages.
|
|
*/
|
|
static inline
|
|
void page_cache_async_readahead(struct address_space *mapping,
|
|
struct file_ra_state *ra, struct file *file,
|
|
struct page *page, pgoff_t index, unsigned long req_count)
|
|
{
|
|
DEFINE_READAHEAD(ractl, file, ra, mapping, index);
|
|
page_cache_async_ra(&ractl, page_folio(page), req_count);
|
|
}
|
|
|
|
static inline struct folio *__readahead_folio(struct readahead_control *ractl)
|
|
{
|
|
struct folio *folio;
|
|
|
|
BUG_ON(ractl->_batch_count > ractl->_nr_pages);
|
|
ractl->_nr_pages -= ractl->_batch_count;
|
|
ractl->_index += ractl->_batch_count;
|
|
|
|
if (!ractl->_nr_pages) {
|
|
ractl->_batch_count = 0;
|
|
return NULL;
|
|
}
|
|
|
|
folio = xa_load(&ractl->mapping->i_pages, ractl->_index);
|
|
VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
|
|
ractl->_batch_count = folio_nr_pages(folio);
|
|
|
|
return folio;
|
|
}
|
|
|
|
/**
|
|
* readahead_page - Get the next page to read.
|
|
* @ractl: The current readahead request.
|
|
*
|
|
* Context: The page is locked and has an elevated refcount. The caller
|
|
* should decreases the refcount once the page has been submitted for I/O
|
|
* and unlock the page once all I/O to that page has completed.
|
|
* Return: A pointer to the next page, or %NULL if we are done.
|
|
*/
|
|
static inline struct page *readahead_page(struct readahead_control *ractl)
|
|
{
|
|
struct folio *folio = __readahead_folio(ractl);
|
|
|
|
return &folio->page;
|
|
}
|
|
|
|
/**
|
|
* readahead_folio - Get the next folio to read.
|
|
* @ractl: The current readahead request.
|
|
*
|
|
* Context: The folio is locked. The caller should unlock the folio once
|
|
* all I/O to that folio has completed.
|
|
* Return: A pointer to the next folio, or %NULL if we are done.
|
|
*/
|
|
static inline struct folio *readahead_folio(struct readahead_control *ractl)
|
|
{
|
|
struct folio *folio = __readahead_folio(ractl);
|
|
|
|
if (folio)
|
|
folio_put(folio);
|
|
return folio;
|
|
}
|
|
|
|
static inline unsigned int __readahead_batch(struct readahead_control *rac,
|
|
struct page **array, unsigned int array_sz)
|
|
{
|
|
unsigned int i = 0;
|
|
XA_STATE(xas, &rac->mapping->i_pages, 0);
|
|
struct page *page;
|
|
|
|
BUG_ON(rac->_batch_count > rac->_nr_pages);
|
|
rac->_nr_pages -= rac->_batch_count;
|
|
rac->_index += rac->_batch_count;
|
|
rac->_batch_count = 0;
|
|
|
|
xas_set(&xas, rac->_index);
|
|
rcu_read_lock();
|
|
xas_for_each(&xas, page, rac->_index + rac->_nr_pages - 1) {
|
|
if (xas_retry(&xas, page))
|
|
continue;
|
|
VM_BUG_ON_PAGE(!PageLocked(page), page);
|
|
VM_BUG_ON_PAGE(PageTail(page), page);
|
|
array[i++] = page;
|
|
rac->_batch_count += thp_nr_pages(page);
|
|
if (i == array_sz)
|
|
break;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return i;
|
|
}
|
|
|
|
/**
|
|
* readahead_page_batch - Get a batch of pages to read.
|
|
* @rac: The current readahead request.
|
|
* @array: An array of pointers to struct page.
|
|
*
|
|
* Context: The pages are locked and have an elevated refcount. The caller
|
|
* should decreases the refcount once the page has been submitted for I/O
|
|
* and unlock the page once all I/O to that page has completed.
|
|
* Return: The number of pages placed in the array. 0 indicates the request
|
|
* is complete.
|
|
*/
|
|
#define readahead_page_batch(rac, array) \
|
|
__readahead_batch(rac, array, ARRAY_SIZE(array))
|
|
|
|
/**
|
|
* readahead_pos - The byte offset into the file of this readahead request.
|
|
* @rac: The readahead request.
|
|
*/
|
|
static inline loff_t readahead_pos(struct readahead_control *rac)
|
|
{
|
|
return (loff_t)rac->_index * PAGE_SIZE;
|
|
}
|
|
|
|
/**
|
|
* readahead_length - The number of bytes in this readahead request.
|
|
* @rac: The readahead request.
|
|
*/
|
|
static inline size_t readahead_length(struct readahead_control *rac)
|
|
{
|
|
return rac->_nr_pages * PAGE_SIZE;
|
|
}
|
|
|
|
/**
|
|
* readahead_index - The index of the first page in this readahead request.
|
|
* @rac: The readahead request.
|
|
*/
|
|
static inline pgoff_t readahead_index(struct readahead_control *rac)
|
|
{
|
|
return rac->_index;
|
|
}
|
|
|
|
/**
|
|
* readahead_count - The number of pages in this readahead request.
|
|
* @rac: The readahead request.
|
|
*/
|
|
static inline unsigned int readahead_count(struct readahead_control *rac)
|
|
{
|
|
return rac->_nr_pages;
|
|
}
|
|
|
|
/**
|
|
* readahead_batch_length - The number of bytes in the current batch.
|
|
* @rac: The readahead request.
|
|
*/
|
|
static inline size_t readahead_batch_length(struct readahead_control *rac)
|
|
{
|
|
return rac->_batch_count * PAGE_SIZE;
|
|
}
|
|
|
|
static inline unsigned long dir_pages(struct inode *inode)
|
|
{
|
|
return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>
|
|
PAGE_SHIFT;
|
|
}
|
|
|
|
/**
|
|
* folio_mkwrite_check_truncate - check if folio was truncated
|
|
* @folio: the folio to check
|
|
* @inode: the inode to check the folio against
|
|
*
|
|
* Return: the number of bytes in the folio up to EOF,
|
|
* or -EFAULT if the folio was truncated.
|
|
*/
|
|
static inline ssize_t folio_mkwrite_check_truncate(struct folio *folio,
|
|
struct inode *inode)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
pgoff_t index = size >> PAGE_SHIFT;
|
|
size_t offset = offset_in_folio(folio, size);
|
|
|
|
if (!folio->mapping)
|
|
return -EFAULT;
|
|
|
|
/* folio is wholly inside EOF */
|
|
if (folio_next_index(folio) - 1 < index)
|
|
return folio_size(folio);
|
|
/* folio is wholly past EOF */
|
|
if (folio->index > index || !offset)
|
|
return -EFAULT;
|
|
/* folio is partially inside EOF */
|
|
return offset;
|
|
}
|
|
|
|
/**
|
|
* page_mkwrite_check_truncate - check if page was truncated
|
|
* @page: the page to check
|
|
* @inode: the inode to check the page against
|
|
*
|
|
* Returns the number of bytes in the page up to EOF,
|
|
* or -EFAULT if the page was truncated.
|
|
*/
|
|
static inline int page_mkwrite_check_truncate(struct page *page,
|
|
struct inode *inode)
|
|
{
|
|
loff_t size = i_size_read(inode);
|
|
pgoff_t index = size >> PAGE_SHIFT;
|
|
int offset = offset_in_page(size);
|
|
|
|
if (page->mapping != inode->i_mapping)
|
|
return -EFAULT;
|
|
|
|
/* page is wholly inside EOF */
|
|
if (page->index < index)
|
|
return PAGE_SIZE;
|
|
/* page is wholly past EOF */
|
|
if (page->index > index || !offset)
|
|
return -EFAULT;
|
|
/* page is partially inside EOF */
|
|
return offset;
|
|
}
|
|
|
|
/**
|
|
* i_blocks_per_folio - How many blocks fit in this folio.
|
|
* @inode: The inode which contains the blocks.
|
|
* @folio: The folio.
|
|
*
|
|
* If the block size is larger than the size of this folio, return zero.
|
|
*
|
|
* Context: The caller should hold a refcount on the folio to prevent it
|
|
* from being split.
|
|
* Return: The number of filesystem blocks covered by this folio.
|
|
*/
|
|
static inline
|
|
unsigned int i_blocks_per_folio(struct inode *inode, struct folio *folio)
|
|
{
|
|
return folio_size(folio) >> inode->i_blkbits;
|
|
}
|
|
|
|
static inline
|
|
unsigned int i_blocks_per_page(struct inode *inode, struct page *page)
|
|
{
|
|
return i_blocks_per_folio(inode, page_folio(page));
|
|
}
|
|
#endif /* _LINUX_PAGEMAP_H */
|