1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/file.h>
6 #include <linux/swap.h>
7 #include <linux/mempolicy.h>
8 #include <linux/pagemap.h>
9 #include <linux/percpu_counter.h>
10 #include <linux/xattr.h>
12 /* inode in-kernel data */
14 struct shmem_inode_info
{
16 unsigned int seals
; /* shmem seals */
18 unsigned long alloced
; /* data pages alloced to file */
19 unsigned long swapped
; /* subtotal assigned to swap */
20 struct list_head shrinklist
; /* shrinkable hpage inodes */
21 struct list_head swaplist
; /* chain of maybes on swap */
22 struct shared_policy policy
; /* NUMA memory alloc policy */
23 struct simple_xattrs xattrs
; /* list of xattrs */
24 atomic_t stop_eviction
; /* hold when working on inode */
25 struct inode vfs_inode
;
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 umode_t mode
; /* Mount mode for root directory */
35 unsigned char huge
; /* Whether to try for hugepages */
36 kuid_t uid
; /* Mount uid for root directory */
37 kgid_t gid
; /* Mount gid for root directory */
38 struct mempolicy
*mpol
; /* default memory policy for mappings */
39 spinlock_t shrinklist_lock
; /* Protects shrinklist */
40 struct list_head shrinklist
; /* List of shinkable inodes */
41 unsigned long shrinklist_len
; /* Length of shrinklist */
44 static inline struct shmem_inode_info
*SHMEM_I(struct inode
*inode
)
46 return container_of(inode
, struct shmem_inode_info
, vfs_inode
);
50 * Functions in mm/shmem.c called directly from elsewhere:
52 extern int shmem_init(void);
53 extern int shmem_fill_super(struct super_block
*sb
, void *data
, int silent
);
54 extern struct file
*shmem_file_setup(const char *name
,
55 loff_t size
, unsigned long flags
);
56 extern struct file
*shmem_kernel_file_setup(const char *name
, loff_t size
,
58 extern struct file
*shmem_file_setup_with_mnt(struct vfsmount
*mnt
,
59 const char *name
, loff_t size
, unsigned long flags
);
60 extern int shmem_zero_setup(struct vm_area_struct
*);
61 extern unsigned long shmem_get_unmapped_area(struct file
*, unsigned long addr
,
62 unsigned long len
, unsigned long pgoff
, unsigned long flags
);
63 extern int shmem_lock(struct file
*file
, int lock
, struct user_struct
*user
);
65 extern bool shmem_mapping(struct address_space
*mapping
);
67 static inline bool shmem_mapping(struct address_space
*mapping
)
71 #endif /* CONFIG_SHMEM */
72 extern void shmem_unlock_mapping(struct address_space
*mapping
);
73 extern struct page
*shmem_read_mapping_page_gfp(struct address_space
*mapping
,
74 pgoff_t index
, gfp_t gfp_mask
);
75 extern void shmem_truncate_range(struct inode
*inode
, loff_t start
, loff_t end
);
76 extern int shmem_unuse(unsigned int type
, bool frontswap
,
77 unsigned long *fs_pages_to_unuse
);
79 extern unsigned long shmem_swap_usage(struct vm_area_struct
*vma
);
80 extern unsigned long shmem_partial_swap_usage(struct address_space
*mapping
,
81 pgoff_t start
, pgoff_t end
);
83 /* Flag allocation requirements to shmem_getpage */
85 SGP_READ
, /* don't exceed i_size, don't allocate page */
86 SGP_CACHE
, /* don't exceed i_size, may allocate page */
87 SGP_NOHUGE
, /* like SGP_CACHE, but no huge pages */
88 SGP_HUGE
, /* like SGP_CACHE, huge pages preferred */
89 SGP_WRITE
, /* may exceed i_size, may allocate !Uptodate page */
90 SGP_FALLOC
, /* like SGP_WRITE, but make existing page Uptodate */
93 extern int shmem_getpage(struct inode
*inode
, pgoff_t index
,
94 struct page
**pagep
, enum sgp_type sgp
);
96 static inline struct page
*shmem_read_mapping_page(
97 struct address_space
*mapping
, pgoff_t index
)
99 return shmem_read_mapping_page_gfp(mapping
, index
,
100 mapping_gfp_mask(mapping
));
103 static inline bool shmem_file(struct file
*file
)
105 if (!IS_ENABLED(CONFIG_SHMEM
))
107 if (!file
|| !file
->f_mapping
)
109 return shmem_mapping(file
->f_mapping
);
112 extern bool shmem_charge(struct inode
*inode
, long pages
);
113 extern void shmem_uncharge(struct inode
*inode
, long pages
);
115 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
116 extern bool shmem_huge_enabled(struct vm_area_struct
*vma
);
118 static inline bool shmem_huge_enabled(struct vm_area_struct
*vma
)
125 extern int shmem_mcopy_atomic_pte(struct mm_struct
*dst_mm
, pmd_t
*dst_pmd
,
126 struct vm_area_struct
*dst_vma
,
127 unsigned long dst_addr
,
128 unsigned long src_addr
,
129 struct page
**pagep
);
130 extern int shmem_mfill_zeropage_pte(struct mm_struct
*dst_mm
,
132 struct vm_area_struct
*dst_vma
,
133 unsigned long dst_addr
);
135 #define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
136 src_addr, pagep) ({ BUG(); 0; })
137 #define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
138 dst_addr) ({ BUG(); 0; })