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 struct page;
   9 struct file;
  10 struct inode;
  11 struct super_block;
  12 struct user_struct;
  13 struct vm_area_struct;
  14
  15 /* inode in-kernel data */
  16
  17 #define SHMEM_NR_DIRECT 16
  18
  19 #define SHMEM_SYMLINK_INLINE_LEN (SHMEM_NR_DIRECT * sizeof(swp_entry_t))
  20
  21 struct shmem_inode_info {
  22         spinlock_t              lock;
  23         unsigned long           flags;
  24         unsigned long           alloced;        /* data pages alloced to file */
  25         unsigned long           swapped;        /* subtotal assigned to swap */
  26         unsigned long           next_index;     /* highest alloced index + 1 */
  27         struct shared_policy    policy;         /* NUMA memory alloc policy */
  28         struct page             *i_indirect;    /* top indirect blocks page */
  29         union {
  30                 swp_entry_t     i_direct[SHMEM_NR_DIRECT]; /* first blocks */
  31                 char            inline_symlink[SHMEM_SYMLINK_INLINE_LEN];
  32         };
  33         struct list_head        swaplist;       /* chain of maybes on swap */
  34         struct list_head        xattr_list;     /* list of shmem_xattr */
  35         struct inode            vfs_inode;
  36 };
  37
  38 struct shmem_sb_info {
  39         unsigned long max_blocks;   /* How many blocks are allowed */
  40         struct percpu_counter used_blocks;  /* How many are allocated */
  41         unsigned long max_inodes;   /* How many inodes are allowed */
  42         unsigned long free_inodes;  /* How many are left for allocation */
  43         spinlock_t stat_lock;       /* Serialize shmem_sb_info changes */
  44         uid_t uid;                  /* Mount uid for root directory */
  45         gid_t gid;                  /* Mount gid for root directory */
  46         mode_t mode;                /* Mount mode for root directory */
  47         struct mempolicy *mpol;     /* default memory policy for mappings */
  48 };
  49
  50 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
  51 {
  52         return container_of(inode, struct shmem_inode_info, vfs_inode);
  53 }
  54
  55 /*
  56  * Functions in mm/shmem.c called directly from elsewhere:
  57  */
  58 extern int init_tmpfs(void);
  59 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  60 extern struct file *shmem_file_setup(const char *name,
  61                                         loff_t size, unsigned long flags);
  62 extern int shmem_zero_setup(struct vm_area_struct *);
  63 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
  64 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
  65 extern int shmem_unuse(swp_entry_t entry, struct page *page);
  66 extern void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
  67                                         struct page **pagep, swp_entry_t *ent);
  68
  69 #endif