136 lines
5.0 KiB
C
136 lines
5.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __SHMEM_FS_H
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#define __SHMEM_FS_H
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#include <linux/file.h>
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#include <linux/swap.h>
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#include <linux/mempolicy.h>
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#include <linux/pagemap.h>
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#include <linux/percpu_counter.h>
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#include <linux/xattr.h>
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#include <linux/fs_parser.h>
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/* inode in-kernel data */
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struct shmem_inode_info {
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spinlock_t lock;
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unsigned int seals; /* shmem seals */
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unsigned long flags;
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unsigned long alloced; /* data pages alloced to file */
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unsigned long swapped; /* subtotal assigned to swap */
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struct list_head shrinklist; /* shrinkable hpage inodes */
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struct list_head swaplist; /* chain of maybes on swap */
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struct shared_policy policy; /* NUMA memory alloc policy */
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struct simple_xattrs xattrs; /* list of xattrs */
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atomic_t stop_eviction; /* hold when working on inode */
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struct inode vfs_inode;
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};
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struct shmem_sb_info {
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unsigned long max_blocks; /* How many blocks are allowed */
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struct percpu_counter used_blocks; /* How many are allocated */
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unsigned long max_inodes; /* How many inodes are allowed */
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unsigned long free_inodes; /* How many are left for allocation */
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spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
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umode_t mode; /* Mount mode for root directory */
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unsigned char huge; /* Whether to try for hugepages */
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kuid_t uid; /* Mount uid for root directory */
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kgid_t gid; /* Mount gid for root directory */
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struct mempolicy *mpol; /* default memory policy for mappings */
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spinlock_t shrinklist_lock; /* Protects shrinklist */
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struct list_head shrinklist; /* List of shinkable inodes */
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unsigned long shrinklist_len; /* Length of shrinklist */
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};
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static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
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{
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return container_of(inode, struct shmem_inode_info, vfs_inode);
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}
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/*
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* Functions in mm/shmem.c called directly from elsewhere:
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*/
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extern const struct fs_parameter_spec shmem_fs_parameters[];
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extern int shmem_init(void);
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extern int shmem_init_fs_context(struct fs_context *fc);
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extern struct file *shmem_file_setup(const char *name,
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loff_t size, unsigned long flags);
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extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
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unsigned long flags);
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extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt,
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const char *name, loff_t size, unsigned long flags);
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extern int shmem_zero_setup(struct vm_area_struct *);
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extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags);
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extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
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#ifdef CONFIG_SHMEM
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extern bool shmem_mapping(struct address_space *mapping);
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#else
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static inline bool shmem_mapping(struct address_space *mapping)
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{
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return false;
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}
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#endif /* CONFIG_SHMEM */
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extern void shmem_unlock_mapping(struct address_space *mapping);
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extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
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pgoff_t index, gfp_t gfp_mask);
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extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
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extern int shmem_unuse(unsigned int type, bool frontswap,
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unsigned long *fs_pages_to_unuse);
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extern bool shmem_huge_enabled(struct vm_area_struct *vma);
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extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
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extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
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pgoff_t start, pgoff_t end);
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/* Flag allocation requirements to shmem_getpage */
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enum sgp_type {
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SGP_READ, /* don't exceed i_size, don't allocate page */
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SGP_CACHE, /* don't exceed i_size, may allocate page */
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SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */
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SGP_HUGE, /* like SGP_CACHE, huge pages preferred */
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SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
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SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
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};
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extern int shmem_getpage(struct inode *inode, pgoff_t index,
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struct page **pagep, enum sgp_type sgp);
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static inline struct page *shmem_read_mapping_page(
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struct address_space *mapping, pgoff_t index)
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{
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return shmem_read_mapping_page_gfp(mapping, index,
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mapping_gfp_mask(mapping));
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}
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static inline bool shmem_file(struct file *file)
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{
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if (!IS_ENABLED(CONFIG_SHMEM))
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return false;
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if (!file || !file->f_mapping)
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return false;
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return shmem_mapping(file->f_mapping);
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}
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extern bool shmem_charge(struct inode *inode, long pages);
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extern void shmem_uncharge(struct inode *inode, long pages);
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#ifdef CONFIG_SHMEM
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extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
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struct vm_area_struct *dst_vma,
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unsigned long dst_addr,
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unsigned long src_addr,
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struct page **pagep);
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extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm,
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pmd_t *dst_pmd,
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struct vm_area_struct *dst_vma,
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unsigned long dst_addr);
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#else
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#define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
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src_addr, pagep) ({ BUG(); 0; })
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#define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
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dst_addr) ({ BUG(); 0; })
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#endif
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#endif
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