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>
11 /* inode in-kernel data */
13 struct shmem_inode_info
{
15 unsigned int seals
; /* shmem seals */
17 unsigned long alloced
; /* data pages alloced to file */
18 unsigned long swapped
; /* subtotal assigned to swap */
19 struct list_head shrinklist
; /* shrinkable hpage inodes */
20 struct list_head swaplist
; /* chain of maybes on swap */
21 struct shared_policy policy
; /* NUMA memory alloc policy */
22 struct simple_xattrs xattrs
; /* list of xattrs */
23 struct inode vfs_inode
;
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 umode_t mode
; /* Mount mode for root directory */
33 unsigned char huge
; /* Whether to try for hugepages */
34 kuid_t uid
; /* Mount uid for root directory */
35 kgid_t gid
; /* Mount gid for root directory */
36 struct mempolicy
*mpol
; /* default memory policy for mappings */
37 spinlock_t shrinklist_lock
; /* Protects shrinklist */
38 struct list_head shrinklist
; /* List of shinkable inodes */
39 unsigned long shrinklist_len
; /* Length of shrinklist */
42 static inline struct shmem_inode_info
*SHMEM_I(struct inode
*inode
)
44 return container_of(inode
, struct shmem_inode_info
, vfs_inode
);
48 * Functions in mm/shmem.c called directly from elsewhere:
50 extern int shmem_init(void);
51 extern int shmem_fill_super(struct super_block
*sb
, void *data
, int silent
);
52 extern struct file
*shmem_file_setup(const char *name
,
53 loff_t size
, unsigned long flags
);
54 extern struct file
*shmem_kernel_file_setup(const char *name
, loff_t size
,
56 extern int shmem_zero_setup(struct vm_area_struct
*);
57 extern unsigned long shmem_get_unmapped_area(struct file
*, unsigned long addr
,
58 unsigned long len
, unsigned long pgoff
, unsigned long flags
);
59 extern int shmem_lock(struct file
*file
, int lock
, struct user_struct
*user
);
60 extern bool shmem_mapping(struct address_space
*mapping
);
61 extern void shmem_unlock_mapping(struct address_space
*mapping
);
62 extern struct page
*shmem_read_mapping_page_gfp(struct address_space
*mapping
,
63 pgoff_t index
, gfp_t gfp_mask
);
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
);
67 extern unsigned long shmem_swap_usage(struct vm_area_struct
*vma
);
68 extern unsigned long shmem_partial_swap_usage(struct address_space
*mapping
,
69 pgoff_t start
, pgoff_t end
);
71 /* Flag allocation requirements to shmem_getpage */
73 SGP_READ
, /* don't exceed i_size, don't allocate page */
74 SGP_CACHE
, /* don't exceed i_size, may allocate page */
75 SGP_NOHUGE
, /* like SGP_CACHE, but no huge pages */
76 SGP_HUGE
, /* like SGP_CACHE, huge pages preferred */
77 SGP_WRITE
, /* may exceed i_size, may allocate !Uptodate page */
78 SGP_FALLOC
, /* like SGP_WRITE, but make existing page Uptodate */
81 extern int shmem_getpage(struct inode
*inode
, pgoff_t index
,
82 struct page
**pagep
, enum sgp_type sgp
);
84 static inline struct page
*shmem_read_mapping_page(
85 struct address_space
*mapping
, pgoff_t index
)
87 return shmem_read_mapping_page_gfp(mapping
, index
,
88 mapping_gfp_mask(mapping
));
91 static inline bool shmem_file(struct file
*file
)
93 if (!IS_ENABLED(CONFIG_SHMEM
))
95 if (!file
|| !file
->f_mapping
)
97 return shmem_mapping(file
->f_mapping
);
100 extern bool shmem_charge(struct inode
*inode
, long pages
);
101 extern void shmem_uncharge(struct inode
*inode
, long pages
);
105 extern int shmem_add_seals(struct file
*file
, unsigned int seals
);
106 extern int shmem_get_seals(struct file
*file
);
107 extern long shmem_fcntl(struct file
*file
, unsigned int cmd
, unsigned long arg
);
111 static inline long shmem_fcntl(struct file
*f
, unsigned int c
, unsigned long a
)
118 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
119 extern bool shmem_huge_enabled(struct vm_area_struct
*vma
);
121 static inline bool shmem_huge_enabled(struct vm_area_struct
*vma
)