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 extern bool shmem_mapping(struct address_space *mapping); 61 extern void shmem_unlock_mapping(struct address_space *mapping); 62 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 63 pgoff_t index, gfp_t gfp_mask); 64 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 65 extern int shmem_unuse(swp_entry_t entry, struct page *page); 66 67 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); 68 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, 69 pgoff_t start, pgoff_t end); 70 71 /* Flag allocation requirements to shmem_getpage */ 72 enum sgp_type { 73 SGP_READ, /* don't exceed i_size, don't allocate page */ 74 SGP_CACHE, /* don't exceed i_size, may allocate page */ 75 SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */ 76 SGP_HUGE, /* like SGP_CACHE, huge pages preferred */ 77 SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ 78 SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ 79 }; 80 81 extern int shmem_getpage(struct inode *inode, pgoff_t index, 82 struct page **pagep, enum sgp_type sgp); 83 84 static inline struct page *shmem_read_mapping_page( 85 struct address_space *mapping, pgoff_t index) 86 { 87 return shmem_read_mapping_page_gfp(mapping, index, 88 mapping_gfp_mask(mapping)); 89 } 90 91 static inline bool shmem_file(struct file *file) 92 { 93 if (!IS_ENABLED(CONFIG_SHMEM)) 94 return false; 95 if (!file || !file->f_mapping) 96 return false; 97 return shmem_mapping(file->f_mapping); 98 } 99 100 extern bool shmem_charge(struct inode *inode, long pages); 101 extern void shmem_uncharge(struct inode *inode, long pages); 102 103 #ifdef CONFIG_TMPFS 104 105 extern int shmem_add_seals(struct file *file, unsigned int seals); 106 extern int shmem_get_seals(struct file *file); 107 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg); 108 109 #else 110 111 static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a) 112 { 113 return -EINVAL; 114 } 115 116 #endif 117 118 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE 119 extern bool shmem_huge_enabled(struct vm_area_struct *vma); 120 #else 121 static inline bool shmem_huge_enabled(struct vm_area_struct *vma) 122 { 123 return false; 124 } 125 #endif 126 127 #endif 128