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/percpu_counter.h>
   7
   8 /* inode in-kernel data */
   9
  10 #define SHMEM_NR_DIRECT 16
  11
  12 #define SHMEM_SYMLINK_INLINE_LEN (SHMEM_NR_DIRECT * sizeof(swp_entry_t))
  13
  14 struct shmem_inode_info {
  15         spinlock_t              lock;
  16         unsigned long           flags;
  17         unsigned long           alloced;        /* data pages alloced to file */
  18         unsigned long           swapped;        /* subtotal assigned to swap */
  19         unsigned long           next_index;     /* highest alloced index + 1 */
  20         struct shared_policy    policy;         /* NUMA memory alloc policy */
  21         struct page             *i_indirect;    /* top indirect blocks page */
  22         union {
  23                 swp_entry_t     i_direct[SHMEM_NR_DIRECT]; /* first blocks */
  24                 char            inline_symlink[SHMEM_SYMLINK_INLINE_LEN];
  25         };
  26         struct list_head        swaplist;       /* chain of maybes on swap */
  27         struct list_head        xattr_list;     /* list of shmem_xattr */
  28         struct inode            vfs_inode;
  29 };
  30
  31 struct shmem_sb_info {
  32         unsigned long max_blocks;   /* How many blocks are allowed */
  33         struct percpu_counter used_blocks;  /* How many are allocated */
  34         unsigned long max_inodes;   /* How many inodes are allowed */
  35         unsigned long free_inodes;  /* How many are left for allocation */
  36         spinlock_t stat_lock;       /* Serialize shmem_sb_info changes */
  37         uid_t uid;                  /* Mount uid for root directory */
  38         gid_t gid;                  /* Mount gid for root directory */
  39         mode_t mode;                /* Mount mode for root directory */
  40         struct mempolicy *mpol;     /* default memory policy for mappings */
  41 };
  42
  43 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
  44 {
  45         return container_of(inode, struct shmem_inode_info, vfs_inode);
  46 }
  47
  48 extern int init_tmpfs(void);
  49 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  50
  51 #endif