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 #include <linux/xattr.h>
9
10 /* inode in-kernel data */
11
12 struct shmem_inode_info {
13 spinlock_t lock;
14 unsigned long flags;
15 unsigned long alloced; /* data pages alloced to file */
16 union {
17 unsigned long swapped; /* subtotal assigned to swap */
18 char *symlink; /* unswappable short symlink */
19 };
20 struct shared_policy policy; /* NUMA memory alloc policy */
21 struct list_head swaplist; /* chain of maybes on swap */
22 struct simple_xattrs xattrs; /* list of xattrs */
23 struct inode vfs_inode;
24 };
25
26 struct shmem_sb_info {
27 unsigned long max_blocks; /* How many blocks are allowed */
28 struct percpu_counter used_blocks; /* How many are allocated */
29 unsigned long max_inodes; /* How many inodes are allowed */
30 unsigned long free_inodes; /* How many are left for allocation */
31 spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
32 kuid_t uid; /* Mount uid for root directory */
33 kgid_t gid; /* Mount gid for root directory */
34 umode_t mode; /* Mount mode for root directory */
35 struct mempolicy *mpol; /* default memory policy for mappings */
36 };
37
SHMEM_I(struct inode * inode)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 int shmem_zero_setup(struct vm_area_struct *);
51 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
52 extern void shmem_unlock_mapping(struct address_space *mapping);
53 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
54 pgoff_t index, gfp_t gfp_mask);
55 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
56 extern int shmem_unuse(swp_entry_t entry, struct page *page);
57
shmem_read_mapping_page(struct address_space * mapping,pgoff_t index)58 static inline struct page *shmem_read_mapping_page(
59 struct address_space *mapping, pgoff_t index)
60 {
61 return shmem_read_mapping_page_gfp(mapping, index,
62 mapping_gfp_mask(mapping));
63 }
64
65 #endif
66