Branch data Line data Source code
1 : : /* SPDX-License-Identifier: GPL-2.0 */
2 : : #ifndef __SHMEM_FS_H
3 : : #define __SHMEM_FS_H
4 : :
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>
11 : : #include <linux/fs_parser.h>
12 : :
13 : : /* inode in-kernel data */
14 : :
15 : : struct shmem_inode_info {
16 : : spinlock_t lock;
17 : : unsigned int seals; /* shmem seals */
18 : : unsigned long flags;
19 : : unsigned long alloced; /* data pages alloced to file */
20 : : unsigned long swapped; /* subtotal assigned to swap */
21 : : struct list_head shrinklist; /* shrinkable hpage inodes */
22 : : struct list_head swaplist; /* chain of maybes on swap */
23 : : struct shared_policy policy; /* NUMA memory alloc policy */
24 : : struct simple_xattrs xattrs; /* list of xattrs */
25 : : atomic_t stop_eviction; /* hold when working on inode */
26 : : struct inode vfs_inode;
27 : : };
28 : :
29 : : struct shmem_sb_info {
30 : : unsigned long max_blocks; /* How many blocks are allowed */
31 : : struct percpu_counter used_blocks; /* How many are allocated */
32 : : unsigned long max_inodes; /* How many inodes are allowed */
33 : : unsigned long free_inodes; /* How many are left for allocation */
34 : : spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
35 : : umode_t mode; /* Mount mode for root directory */
36 : : unsigned char huge; /* Whether to try for hugepages */
37 : : kuid_t uid; /* Mount uid for root directory */
38 : : kgid_t gid; /* Mount gid for root directory */
39 : : struct mempolicy *mpol; /* default memory policy for mappings */
40 : : spinlock_t shrinklist_lock; /* Protects shrinklist */
41 : : struct list_head shrinklist; /* List of shinkable inodes */
42 : : unsigned long shrinklist_len; /* Length of shrinklist */
43 : : };
44 : :
45 : 86288 : static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
46 : : {
47 [ + - - + : 86288 : return container_of(inode, struct shmem_inode_info, vfs_inode);
- + - - -
- + + - +
+ - - - +
+ + - +
- ]
48 : : }
49 : :
50 : : /*
51 : : * Functions in mm/shmem.c called directly from elsewhere:
52 : : */
53 : : extern const struct fs_parameter_spec shmem_fs_parameters[];
54 : : extern int shmem_init(void);
55 : : extern int shmem_init_fs_context(struct fs_context *fc);
56 : : extern struct file *shmem_file_setup(const char *name,
57 : : loff_t size, unsigned long flags);
58 : : extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
59 : : unsigned long flags);
60 : : extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt,
61 : : const char *name, loff_t size, unsigned long flags);
62 : : extern int shmem_zero_setup(struct vm_area_struct *);
63 : : extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
64 : : unsigned long len, unsigned long pgoff, unsigned long flags);
65 : : extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
66 : : #ifdef CONFIG_SHMEM
67 : : extern bool shmem_mapping(struct address_space *mapping);
68 : : #else
69 : : static inline bool shmem_mapping(struct address_space *mapping)
70 : : {
71 : : return false;
72 : : }
73 : : #endif /* CONFIG_SHMEM */
74 : : extern void shmem_unlock_mapping(struct address_space *mapping);
75 : : extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
76 : : pgoff_t index, gfp_t gfp_mask);
77 : : extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
78 : : extern int shmem_unuse(unsigned int type, bool frontswap,
79 : : unsigned long *fs_pages_to_unuse);
80 : :
81 : : extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
82 : : extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
83 : : pgoff_t start, pgoff_t end);
84 : :
85 : : /* Flag allocation requirements to shmem_getpage */
86 : : enum sgp_type {
87 : : SGP_READ, /* don't exceed i_size, don't allocate page */
88 : : SGP_CACHE, /* don't exceed i_size, may allocate page */
89 : : SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */
90 : : SGP_HUGE, /* like SGP_CACHE, huge pages preferred */
91 : : SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
92 : : SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
93 : : };
94 : :
95 : : extern int shmem_getpage(struct inode *inode, pgoff_t index,
96 : : struct page **pagep, enum sgp_type sgp);
97 : :
98 : 0 : static inline struct page *shmem_read_mapping_page(
99 : : struct address_space *mapping, pgoff_t index)
100 : : {
101 : 0 : return shmem_read_mapping_page_gfp(mapping, index,
102 : : mapping_gfp_mask(mapping));
103 : : }
104 : :
105 : 0 : static inline bool shmem_file(struct file *file)
106 : : {
107 : 0 : if (!IS_ENABLED(CONFIG_SHMEM))
108 : : return false;
109 [ # # # # ]: 0 : if (!file || !file->f_mapping)
110 : : return false;
111 : 0 : return shmem_mapping(file->f_mapping);
112 : : }
113 : :
114 : : extern bool shmem_charge(struct inode *inode, long pages);
115 : : extern void shmem_uncharge(struct inode *inode, long pages);
116 : :
117 : : #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
118 : : extern bool shmem_huge_enabled(struct vm_area_struct *vma);
119 : : #else
120 : : static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
121 : : {
122 : : return false;
123 : : }
124 : : #endif
125 : :
126 : : #ifdef CONFIG_SHMEM
127 : : extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
128 : : struct vm_area_struct *dst_vma,
129 : : unsigned long dst_addr,
130 : : unsigned long src_addr,
131 : : struct page **pagep);
132 : : extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm,
133 : : pmd_t *dst_pmd,
134 : : struct vm_area_struct *dst_vma,
135 : : unsigned long dst_addr);
136 : : #else
137 : : #define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
138 : : src_addr, pagep) ({ BUG(); 0; })
139 : : #define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
140 : : dst_addr) ({ BUG(); 0; })
141 : : #endif
142 : :
143 : : #endif
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