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 shared_policy policy; /* NUMA memory alloc policy */ 20 struct list_head swaplist; /* chain of maybes on swap */ 21 struct simple_xattrs xattrs; /* list of xattrs */ 22 struct inode vfs_inode; 23 }; 24 25 struct shmem_sb_info { 26 unsigned long max_blocks; /* How many blocks are allowed */ 27 struct percpu_counter used_blocks; /* How many are allocated */ 28 unsigned long max_inodes; /* How many inodes are allowed */ 29 unsigned long free_inodes; /* How many are left for allocation */ 30 spinlock_t stat_lock; /* Serialize shmem_sb_info changes */ 31 kuid_t uid; /* Mount uid for root directory */ 32 kgid_t gid; /* Mount gid for root directory */ 33 umode_t mode; /* Mount mode for root directory */ 34 struct mempolicy *mpol; /* default memory policy for mappings */ 35 }; 36 37 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) 38 { 39 return container_of(inode, struct shmem_inode_info, vfs_inode); 40 } 41 42 /* 43 * Functions in mm/shmem.c called directly from elsewhere: 44 */ 45 extern int shmem_init(void); 46 extern int shmem_fill_super(struct super_block *sb, void *data, int silent); 47 extern struct file *shmem_file_setup(const char *name, 48 loff_t size, unsigned long flags); 49 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, 50 unsigned long flags); 51 extern int shmem_zero_setup(struct vm_area_struct *); 52 extern int shmem_lock(struct file *file, int lock, struct user_struct *user); 53 extern bool shmem_mapping(struct address_space *mapping); 54 extern void shmem_unlock_mapping(struct address_space *mapping); 55 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 56 pgoff_t index, gfp_t gfp_mask); 57 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 58 extern int shmem_unuse(swp_entry_t entry, struct page *page); 59 60 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); 61 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, 62 pgoff_t start, pgoff_t end); 63 64 static inline struct page *shmem_read_mapping_page( 65 struct address_space *mapping, pgoff_t index) 66 { 67 return shmem_read_mapping_page_gfp(mapping, index, 68 mapping_gfp_mask(mapping)); 69 } 70 71 #ifdef CONFIG_TMPFS 72 73 extern int shmem_add_seals(struct file *file, unsigned int seals); 74 extern int shmem_get_seals(struct file *file); 75 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg); 76 77 #else 78 79 static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a) 80 { 81 return -EINVAL; 82 } 83 84 #endif 85 86 #endif 87