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
SHMEM_I(struct inode * inode)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
shmem_read_mapping_page(struct address_space * mapping,pgoff_t index)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
65