LXR linux/include/linux/shmem

   1#ifndef __SHMEM_FS_H
   2#define __SHMEM_FS_H
   3
   4#include <linux/swap.h>
   5#include <linux/mempolicy.h>
   6#include <linux/pagemap.h>
   7#include <linux/percpu_counter.h>
   8
   9/* inode in-kernel data */
  10
  11struct shmem_inode_info {
  12        spinlock_t              lock;
  13        unsigned long           flags;
  14        unsigned long           alloced;        /* data pages alloced to file */
  15        union {
  16                unsigned long   swapped;        /* subtotal assigned to swap */
  17                char            *symlink;       /* unswappable short symlink */
  18        };
  19        struct shared_policy    policy;         /* NUMA memory alloc policy */
  20        struct list_head        swaplist;       /* chain of maybes on swap */
  21        struct list_head        xattr_list;     /* list of shmem_xattr */
  22        struct inode            vfs_inode;
  23};
  24
  25struct 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        uid_t uid;                  /* Mount uid for root directory */
  32        gid_t gid;                  /* Mount gid for root directory */
  33        mode_t mode;                /* Mount mode for root directory */
  34        struct mempolicy *mpol;     /* default memory policy for mappings */
  35};
  36
  37static 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 */
  45extern int shmem_init(void);
  46extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  47extern struct file *shmem_file_setup(const char *name,
  48                                        loff_t size, unsigned long flags);
  49extern int shmem_zero_setup(struct vm_area_struct *);
  50extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
  51extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
  52                                        pgoff_t index, gfp_t gfp_mask);
  53extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
  54extern int shmem_unuse(swp_entry_t entry, struct page *page);
  55
  56static inline struct page *shmem_read_mapping_page(
  57                                struct address_space *mapping, pgoff_t index)
  58{
  59        return shmem_read_mapping_page_gfp(mapping, index,
  60                                        mapping_gfp_mask(mapping));
  61}
  62
  63#endif
  64