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#include <linux/xattr.h>
   9
  10/* inode in-kernel data */
  11
  12struct shmem_inode_info {
  13        spinlock_t              lock;
  14        unsigned long           flags;
  15        unsigned long           alloced;        /* data pages alloced to file */
  16        union {
  17                unsigned long   swapped;        /* subtotal assigned to swap */
  18                char            *symlink;       /* unswappable short symlink */
  19        };
  20        struct shared_policy    policy;         /* NUMA memory alloc policy */
  21        struct list_head        swaplist;       /* chain of maybes on swap */
  22        struct simple_xattrs    xattrs;         /* list of xattrs */
  23        struct inode            vfs_inode;
  24};
  25
  26struct 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        kuid_t uid;                 /* Mount uid for root directory */
  33        kgid_t gid;                 /* Mount gid for root directory */
  34        umode_t mode;               /* Mount mode for root directory */
  35        struct mempolicy *mpol;     /* default memory policy for mappings */
  36};
  37
  38static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
  39{
  40        return container_of(inode, struct shmem_inode_info, vfs_inode);
  41}
  42
  43/*
  44 * Functions in mm/shmem.c called directly from elsewhere:
  45 */
  46extern int shmem_init(void);
  47extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  48extern struct file *shmem_file_setup(const char *name,
  49                                        loff_t size, unsigned long flags);
  50extern int shmem_zero_setup(struct vm_area_struct *);
  51extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
  52extern void shmem_unlock_mapping(struct address_space *mapping);
  53extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
  54                                        pgoff_t index, gfp_t gfp_mask);
  55extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
  56extern int shmem_unuse(swp_entry_t entry, struct page *page);
  57
  58static inline struct page *shmem_read_mapping_page(
  59                                struct address_space *mapping, pgoff_t index)
  60{
  61        return shmem_read_mapping_page_gfp(mapping, index,
  62                                        mapping_gfp_mask(mapping));
  63}
  64
  65#endif
  66