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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 | bool full_inums; /* If i_ino should be uint or ino_t */ | |
40 | ino_t next_ino; /* The next per-sb inode number to use */ | |
41 | ino_t __percpu *ino_batch; /* The next per-cpu inode number to use */ | |
42 | struct mempolicy *mpol; /* default memory policy for mappings */ | |
43 | spinlock_t shrinklist_lock; /* Protects shrinklist */ | |
44 | struct list_head shrinklist; /* List of shinkable inodes */ | |
45 | unsigned long shrinklist_len; /* Length of shrinklist */ | |
46 | }; | |
47 | ||
48 | static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) | |
49 | { | |
50 | return container_of(inode, struct shmem_inode_info, vfs_inode); | |
51 | } | |
52 | ||
53 | /* | |
54 | * Functions in mm/shmem.c called directly from elsewhere: | |
55 | */ | |
56 | extern const struct fs_parameter_spec shmem_fs_parameters[]; | |
57 | extern int shmem_init(void); | |
58 | extern int shmem_init_fs_context(struct fs_context *fc); | |
59 | extern struct file *shmem_file_setup(const char *name, | |
60 | loff_t size, unsigned long flags); | |
61 | extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, | |
62 | unsigned long flags); | |
63 | extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt, | |
64 | const char *name, loff_t size, unsigned long flags); | |
65 | extern int shmem_zero_setup(struct vm_area_struct *); | |
66 | extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr, | |
67 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
68 | extern int shmem_lock(struct file *file, int lock, struct user_struct *user); | |
69 | #ifdef CONFIG_SHMEM | |
70 | extern const struct address_space_operations shmem_aops; | |
71 | static inline bool shmem_mapping(struct address_space *mapping) | |
72 | { | |
73 | return mapping->a_ops == &shmem_aops; | |
74 | } | |
75 | #else | |
76 | static inline bool shmem_mapping(struct address_space *mapping) | |
77 | { | |
78 | return false; | |
79 | } | |
80 | #endif /* CONFIG_SHMEM */ | |
81 | extern void shmem_unlock_mapping(struct address_space *mapping); | |
82 | extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, | |
83 | pgoff_t index, gfp_t gfp_mask); | |
84 | extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); | |
85 | extern int shmem_unuse(unsigned int type, bool frontswap, | |
86 | unsigned long *fs_pages_to_unuse); | |
87 | ||
88 | extern bool shmem_huge_enabled(struct vm_area_struct *vma); | |
89 | extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); | |
90 | extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, | |
91 | pgoff_t start, pgoff_t end); | |
92 | ||
93 | /* Flag allocation requirements to shmem_getpage */ | |
94 | enum sgp_type { | |
95 | SGP_READ, /* don't exceed i_size, don't allocate page */ | |
96 | SGP_CACHE, /* don't exceed i_size, may allocate page */ | |
97 | SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */ | |
98 | SGP_HUGE, /* like SGP_CACHE, huge pages preferred */ | |
99 | SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ | |
100 | SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ | |
101 | }; | |
102 | ||
103 | extern int shmem_getpage(struct inode *inode, pgoff_t index, | |
104 | struct page **pagep, enum sgp_type sgp); | |
105 | ||
106 | static inline struct page *shmem_read_mapping_page( | |
107 | struct address_space *mapping, pgoff_t index) | |
108 | { | |
109 | return shmem_read_mapping_page_gfp(mapping, index, | |
110 | mapping_gfp_mask(mapping)); | |
111 | } | |
112 | ||
113 | static inline bool shmem_file(struct file *file) | |
114 | { | |
115 | if (!IS_ENABLED(CONFIG_SHMEM)) | |
116 | return false; | |
117 | if (!file || !file->f_mapping) | |
118 | return false; | |
119 | return shmem_mapping(file->f_mapping); | |
120 | } | |
121 | ||
122 | extern bool shmem_charge(struct inode *inode, long pages); | |
123 | extern void shmem_uncharge(struct inode *inode, long pages); | |
124 | ||
125 | #ifdef CONFIG_SHMEM | |
126 | extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, | |
127 | struct vm_area_struct *dst_vma, | |
128 | unsigned long dst_addr, | |
129 | unsigned long src_addr, | |
130 | struct page **pagep); | |
131 | extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm, | |
132 | pmd_t *dst_pmd, | |
133 | struct vm_area_struct *dst_vma, | |
134 | unsigned long dst_addr); | |
135 | #else | |
136 | #define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \ | |
137 | src_addr, pagep) ({ BUG(); 0; }) | |
138 | #define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \ | |
139 | dst_addr) ({ BUG(); 0; }) | |
140 | #endif | |
141 | ||
142 | #endif |