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         unsigned long           swapped;        /* subtotal assigned to swap */
  19         struct shared_policy    policy;         /* NUMA memory alloc policy */
  20         struct list_head        swaplist;       /* chain of maybes on swap */
  21         struct simple_xattrs    xattrs;         /* list of xattrs */
  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         umode_t mode;               /* Mount mode for root directory */
  32         unsigned char huge;         /* Whether to try for hugepages */
  33         kuid_t uid;                 /* Mount uid for root directory */
  34         kgid_t gid;                 /* Mount gid for root directory */
  35         struct mempolicy *mpol;     /* default memory policy for mappings */
  36 };
  37
  38 static 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  */
  46 extern int shmem_init(void);
  47 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
  48 extern struct file *shmem_file_setup(const char *name,
  49                                         loff_t size, unsigned long flags);
  50 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
  51                                             unsigned long flags);
  52 extern int shmem_zero_setup(struct vm_area_struct *);
  53 extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
  54                 unsigned long len, unsigned long pgoff, unsigned long flags);
  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 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
  64 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
  65                                                 pgoff_t start, pgoff_t end);
  66
  67 static inline struct page *shmem_read_mapping_page(
  68                                 struct address_space *mapping, pgoff_t index)
  69 {
  70         return shmem_read_mapping_page_gfp(mapping, index,
  71                                         mapping_gfp_mask(mapping));
  72 }
  73
  74 #ifdef CONFIG_TMPFS
  75
  76 extern int shmem_add_seals(struct file *file, unsigned int seals);
  77 extern int shmem_get_seals(struct file *file);
  78 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
  79
  80 #else
  81
  82 static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a)
  83 {
  84         return -EINVAL;
  85 }
  86
  87 #endif
  88
  89 #endif