include/linux/shmem_fs.h

   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
  11 struct 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
  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         uid_t uid;                  /* Mount uid for root directory */
  32         gid_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 int shmem_zero_setup(struct vm_area_struct *);
  50 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
  51 extern void shmem_unlock_mapping(struct address_space *mapping);
  52 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
  53                                         pgoff_t index, gfp_t gfp_mask);
  54 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
  55 extern int shmem_unuse(swp_entry_t entry, struct page *page);
  56
  57 static inline struct page *shmem_read_mapping_page(
  58                                 struct address_space *mapping, pgoff_t index)
  59 {
  60         return shmem_read_mapping_page_gfp(mapping, index,
  61                                         mapping_gfp_mask(mapping));
  62 }
  63
  64 #endif