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