include/linux/shmem_fs.h

   1 #ifndef __SHMEM_FS_H
   2 #define __SHMEM_FS_H
   3
   4 #include <linux/file.h>
   5 #include <linux/swap.h>
   6 #include <linux/mempolicy.h>
   7 #include <linux/pagemap.h>
   8 #include <linux/percpu_counter.h>
   9 #include <linux/xattr.h>
  10
  11 /* inode in-kernel data */
  12
  13 struct shmem_inode_info {
  14         spinlock_t              lock;
  15         unsigned int            seals;          /* shmem seals */
  16         unsigned long           flags;
  17         unsigned long           alloced;        /* data pages alloced to file */
  18         union {
  19                 unsigned long   swapped;        /* subtotal assigned to swap */
  20                 char            *symlink;       /* unswappable short symlink */
  21         };
  22         struct shared_policy    policy;         /* NUMA memory alloc policy */
  23         struct list_head        swaplist;       /* chain of maybes on swap */
  24         struct simple_xattrs    xattrs;         /* list of xattrs */
  25         struct inode            vfs_inode;
  26 };
  27
  28 struct shmem_sb_info {
  29         unsigned long max_blocks;   /* How many blocks are allowed */
  30         struct percpu_counter used_blocks;  /* How many are allocated */
  31         unsigned long max_inodes;   /* How many inodes are allowed */
  32         unsigned long free_inodes;  /* How many are left for allocation */
  33         spinlock_t stat_lock;       /* Serialize shmem_sb_info changes */
  34         kuid_t uid;                 /* Mount uid for root directory */
  35         kgid_t gid;                 /* Mount gid for root directory */
  36         umode_t mode;               /* Mount mode for root directory */
  37         struct mempolicy *mpol;     /* default memory policy for mappings */
  38 };
  39
  40 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
  41 {
  42         return container_of(inode, struct shmem_inode_info, vfs_inode);
  43 }
  44
  45 /*
  46  * Functions in mm/shmem.c called directly from elsewhere:
  47  */
  48 extern int shmem_init(void);
  49 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  50 extern struct file *shmem_file_setup(const char *name,
  51                                         loff_t size, unsigned long flags);
  52 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
  53                                             unsigned long flags);
  54 extern int shmem_zero_setup(struct vm_area_struct *);
  55 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
  56 extern bool shmem_mapping(struct address_space *mapping);
  57 extern void shmem_unlock_mapping(struct address_space *mapping);
  58 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
  59                                         pgoff_t index, gfp_t gfp_mask);
  60 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
  61 extern int shmem_unuse(swp_entry_t entry, struct page *page);
  62
  63 static inline struct page *shmem_read_mapping_page(
  64                                 struct address_space *mapping, pgoff_t index)
  65 {
  66         return shmem_read_mapping_page_gfp(mapping, index,
  67                                         mapping_gfp_mask(mapping));
  68 }
  69
  70 #ifdef CONFIG_TMPFS
  71
  72 extern int shmem_add_seals(struct file *file, unsigned int seals);
  73 extern int shmem_get_seals(struct file *file);
  74 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
  75
  76 #else
  77
  78 static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a)
  79 {
  80         return -EINVAL;
  81 }
  82
  83 #endif
  84
  85 #endif