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 13struct 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 union { 19 unsigned long swapped; /* subtotal assigned to swap */ 20 char *symlink; /* unswappable short symlink */ 21 }; 22 struct shared_policy policy; /* NUMA memory alloc policy */ 23 struct list_head swaplist; /* chain of maybes on swap */ 24 struct simple_xattrs xattrs; /* list of xattrs */ 25 struct inode vfs_inode; 26}; 27 28struct shmem_sb_info { 29 unsigned long max_blocks; /* How many blocks are allowed */ 30 struct percpu_counter used_blocks; /* How many are allocated */ 31 unsigned long max_inodes; /* How many inodes are allowed */ 32 unsigned long free_inodes; /* How many are left for allocation */ 33 spinlock_t stat_lock; /* Serialize shmem_sb_info changes */ 34 kuid_t uid; /* Mount uid for root directory */ 35 kgid_t gid; /* Mount gid for root directory */ 36 umode_t mode; /* Mount mode for root directory */ 37 struct mempolicy *mpol; /* default memory policy for mappings */ 38}; 39 40static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) 41{ 42 return container_of(inode, struct shmem_inode_info, vfs_inode); 43} 44 45/* 46 * Functions in mm/shmem.c called directly from elsewhere: 47 */ 48extern int shmem_init(void); 49extern int shmem_fill_super(struct super_block *sb, void *data, int silent); 50extern struct file *shmem_file_setup(const char *name, 51 loff_t size, unsigned long flags); 52extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, 53 unsigned long flags); 54extern int shmem_zero_setup(struct vm_area_struct *); 55extern int shmem_lock(struct file *file, int lock, struct user_struct *user); 56extern bool shmem_mapping(struct address_space *mapping); 57extern void shmem_unlock_mapping(struct address_space *mapping); 58extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 59 pgoff_t index, gfp_t gfp_mask); 60extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 61extern int shmem_unuse(swp_entry_t entry, struct page *page); 62 63static inline struct page *shmem_read_mapping_page( 64 struct address_space *mapping, pgoff_t index) 65{ 66 return shmem_read_mapping_page_gfp(mapping, index, 67 mapping_gfp_mask(mapping)); 68} 69 70#ifdef CONFIG_TMPFS 71 72extern int shmem_add_seals(struct file *file, unsigned int seals); 73extern int shmem_get_seals(struct file *file); 74extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg); 75 76#else 77 78static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a) 79{ 80 return -EINVAL; 81} 82 83#endif 84 85#endif 86