1 #ifndef __SHMEM_FS_H 2 #define __SHMEM_FS_H 3 4 #include <linux/file.h> 5 #include <linux/swap.h> 6 #include <linux/mempolicy.h> 7 #include <linux/pagemap.h> 8 #include <linux/percpu_counter.h> 9 #include <linux/xattr.h> 10 11 /* inode in-kernel data */ 12 13 struct shmem_inode_info { 14 spinlock_t lock; 15 unsigned int seals; /* shmem seals */ 16 unsigned long flags; 17 unsigned long alloced; /* data pages alloced to file */ 18 unsigned long swapped; /* subtotal assigned to swap */ 19 struct list_head shrinklist; /* shrinkable hpage inodes */ 20 struct list_head swaplist; /* chain of maybes on swap */ 21 struct shared_policy policy; /* NUMA memory alloc policy */ 22 struct simple_xattrs xattrs; /* list of xattrs */ 23 struct inode vfs_inode; 24 }; 25 26 struct shmem_sb_info { 27 unsigned long max_blocks; /* How many blocks are allowed */ 28 struct percpu_counter used_blocks; /* How many are allocated */ 29 unsigned long max_inodes; /* How many inodes are allowed */ 30 unsigned long free_inodes; /* How many are left for allocation */ 31 spinlock_t stat_lock; /* Serialize shmem_sb_info changes */ 32 umode_t mode; /* Mount mode for root directory */ 33 unsigned char huge; /* Whether to try for hugepages */ 34 kuid_t uid; /* Mount uid for root directory */ 35 kgid_t gid; /* Mount gid for root directory */ 36 struct mempolicy *mpol; /* default memory policy for mappings */ 37 spinlock_t shrinklist_lock; /* Protects shrinklist */ 38 struct list_head shrinklist; /* List of shinkable inodes */ 39 unsigned long shrinklist_len; /* Length of shrinklist */ 40 }; 41 42 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) 43 { 44 return container_of(inode, struct shmem_inode_info, vfs_inode); 45 } 46 47 /* 48 * Functions in mm/shmem.c called directly from elsewhere: 49 */ 50 extern int shmem_init(void); 51 extern int shmem_fill_super(struct super_block *sb, void *data, int silent); 52 extern struct file *shmem_file_setup(const char *name, 53 loff_t size, unsigned long flags); 54 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, 55 unsigned long flags); 56 extern int shmem_zero_setup(struct vm_area_struct *); 57 extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr, 58 unsigned long len, unsigned long pgoff, unsigned long flags); 59 extern int shmem_lock(struct file *file, int lock, struct user_struct *user); 60 #ifdef CONFIG_SHMEM 61 extern bool shmem_mapping(struct address_space *mapping); 62 #else 63 static inline bool shmem_mapping(struct address_space *mapping) 64 { 65 return false; 66 } 67 #endif /* CONFIG_SHMEM */ 68 extern void shmem_unlock_mapping(struct address_space *mapping); 69 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 70 pgoff_t index, gfp_t gfp_mask); 71 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 72 extern int shmem_unuse(swp_entry_t entry, struct page *page); 73 74 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); 75 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, 76 pgoff_t start, pgoff_t end); 77 78 /* Flag allocation requirements to shmem_getpage */ 79 enum sgp_type { 80 SGP_READ, /* don't exceed i_size, don't allocate page */ 81 SGP_CACHE, /* don't exceed i_size, may allocate page */ 82 SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */ 83 SGP_HUGE, /* like SGP_CACHE, huge pages preferred */ 84 SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ 85 SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ 86 }; 87 88 extern int shmem_getpage(struct inode *inode, pgoff_t index, 89 struct page **pagep, enum sgp_type sgp); 90 91 static inline struct page *shmem_read_mapping_page( 92 struct address_space *mapping, pgoff_t index) 93 { 94 return shmem_read_mapping_page_gfp(mapping, index, 95 mapping_gfp_mask(mapping)); 96 } 97 98 static inline bool shmem_file(struct file *file) 99 { 100 if (!IS_ENABLED(CONFIG_SHMEM)) 101 return false; 102 if (!file || !file->f_mapping) 103 return false; 104 return shmem_mapping(file->f_mapping); 105 } 106 107 extern bool shmem_charge(struct inode *inode, long pages); 108 extern void shmem_uncharge(struct inode *inode, long pages); 109 110 #ifdef CONFIG_TMPFS 111 112 extern int shmem_add_seals(struct file *file, unsigned int seals); 113 extern int shmem_get_seals(struct file *file); 114 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg); 115 116 #else 117 118 static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a) 119 { 120 return -EINVAL; 121 } 122 123 #endif 124 125 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE 126 extern bool shmem_huge_enabled(struct vm_area_struct *vma); 127 #else 128 static inline bool shmem_huge_enabled(struct vm_area_struct *vma) 129 { 130 return false; 131 } 132 #endif 133 134 #ifdef CONFIG_SHMEM 135 extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, 136 struct vm_area_struct *dst_vma, 137 unsigned long dst_addr, 138 unsigned long src_addr, 139 struct page **pagep); 140 extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm, 141 pmd_t *dst_pmd, 142 struct vm_area_struct *dst_vma, 143 unsigned long dst_addr); 144 #else 145 #define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \ 146 src_addr, pagep) ({ BUG(); 0; }) 147 #define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \ 148 dst_addr) ({ BUG(); 0; }) 149 #endif 150 151 #endif 152