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 | #include <linux/userfaultfd_k.h> |
13 | |
14 | /* inode in-kernel data */ |
15 | |
16 | #ifdef CONFIG_TMPFS_QUOTA |
17 | #define SHMEM_MAXQUOTAS 2 |
18 | #endif |
19 | |
20 | struct shmem_inode_info { |
21 | spinlock_t lock; |
22 | unsigned int seals; /* shmem seals */ |
23 | unsigned long flags; |
24 | unsigned long alloced; /* data pages alloced to file */ |
25 | unsigned long swapped; /* subtotal assigned to swap */ |
26 | union { |
27 | struct offset_ctx dir_offsets; /* stable directory offsets */ |
28 | struct { |
29 | struct list_head shrinklist; /* shrinkable hpage inodes */ |
30 | struct list_head swaplist; /* chain of maybes on swap */ |
31 | }; |
32 | }; |
33 | struct timespec64 i_crtime; /* file creation time */ |
34 | struct shared_policy policy; /* NUMA memory alloc policy */ |
35 | struct simple_xattrs xattrs; /* list of xattrs */ |
36 | pgoff_t fallocend; /* highest fallocate endindex */ |
37 | unsigned int fsflags; /* for FS_IOC_[SG]ETFLAGS */ |
38 | atomic_t stop_eviction; /* hold when working on inode */ |
39 | #ifdef CONFIG_TMPFS_QUOTA |
40 | struct dquot __rcu *i_dquot[MAXQUOTAS]; |
41 | #endif |
42 | struct inode vfs_inode; |
43 | }; |
44 | |
45 | #define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE |
46 | #define SHMEM_FL_USER_MODIFIABLE \ |
47 | (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL) |
48 | #define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL) |
49 | |
50 | struct shmem_quota_limits { |
51 | qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */ |
52 | qsize_t usrquota_ihardlimit; /* Default user quota inode hard limit */ |
53 | qsize_t grpquota_bhardlimit; /* Default group quota block hard limit */ |
54 | qsize_t grpquota_ihardlimit; /* Default group quota inode hard limit */ |
55 | }; |
56 | |
57 | struct shmem_sb_info { |
58 | unsigned long max_blocks; /* How many blocks are allowed */ |
59 | struct percpu_counter used_blocks; /* How many are allocated */ |
60 | unsigned long max_inodes; /* How many inodes are allowed */ |
61 | unsigned long free_ispace; /* How much ispace left for allocation */ |
62 | raw_spinlock_t stat_lock; /* Serialize shmem_sb_info changes */ |
63 | umode_t mode; /* Mount mode for root directory */ |
64 | unsigned char huge; /* Whether to try for hugepages */ |
65 | kuid_t uid; /* Mount uid for root directory */ |
66 | kgid_t gid; /* Mount gid for root directory */ |
67 | bool full_inums; /* If i_ino should be uint or ino_t */ |
68 | bool noswap; /* ignores VM reclaim / swap requests */ |
69 | ino_t next_ino; /* The next per-sb inode number to use */ |
70 | ino_t __percpu *ino_batch; /* The next per-cpu inode number to use */ |
71 | struct mempolicy *mpol; /* default memory policy for mappings */ |
72 | spinlock_t shrinklist_lock; /* Protects shrinklist */ |
73 | struct list_head shrinklist; /* List of shinkable inodes */ |
74 | unsigned long shrinklist_len; /* Length of shrinklist */ |
75 | struct shmem_quota_limits qlimits; /* Default quota limits */ |
76 | }; |
77 | |
78 | static inline struct shmem_inode_info *SHMEM_I(struct inode *inode) |
79 | { |
80 | return container_of(inode, struct shmem_inode_info, vfs_inode); |
81 | } |
82 | |
83 | /* |
84 | * Functions in mm/shmem.c called directly from elsewhere: |
85 | */ |
86 | extern const struct fs_parameter_spec shmem_fs_parameters[]; |
87 | extern void shmem_init(void); |
88 | extern int shmem_init_fs_context(struct fs_context *fc); |
89 | extern struct file *shmem_file_setup(const char *name, |
90 | loff_t size, unsigned long flags); |
91 | extern struct file *shmem_kernel_file_setup(const char *name, loff_t size, |
92 | unsigned long flags); |
93 | extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt, |
94 | const char *name, loff_t size, unsigned long flags); |
95 | extern int shmem_zero_setup(struct vm_area_struct *); |
96 | extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr, |
97 | unsigned long len, unsigned long pgoff, unsigned long flags); |
98 | extern int shmem_lock(struct file *file, int lock, struct ucounts *ucounts); |
99 | #ifdef CONFIG_SHMEM |
100 | bool shmem_mapping(struct address_space *mapping); |
101 | #else |
102 | static inline bool shmem_mapping(struct address_space *mapping) |
103 | { |
104 | return false; |
105 | } |
106 | #endif /* CONFIG_SHMEM */ |
107 | extern void shmem_unlock_mapping(struct address_space *mapping); |
108 | extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, |
109 | pgoff_t index, gfp_t gfp_mask); |
110 | extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); |
111 | int shmem_unuse(unsigned int type); |
112 | |
113 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
114 | extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, |
115 | struct mm_struct *mm, unsigned long vm_flags); |
116 | #else |
117 | static __always_inline bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, |
118 | struct mm_struct *mm, unsigned long vm_flags) |
119 | { |
120 | return false; |
121 | } |
122 | #endif |
123 | |
124 | #ifdef CONFIG_SHMEM |
125 | extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); |
126 | #else |
127 | static inline unsigned long shmem_swap_usage(struct vm_area_struct *vma) |
128 | { |
129 | return 0; |
130 | } |
131 | #endif |
132 | extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, |
133 | pgoff_t start, pgoff_t end); |
134 | |
135 | /* Flag allocation requirements to shmem_get_folio */ |
136 | enum sgp_type { |
137 | SGP_READ, /* don't exceed i_size, don't allocate page */ |
138 | SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */ |
139 | SGP_CACHE, /* don't exceed i_size, may allocate page */ |
140 | SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ |
141 | SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ |
142 | }; |
143 | |
144 | int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop, |
145 | enum sgp_type sgp); |
146 | struct folio *shmem_read_folio_gfp(struct address_space *mapping, |
147 | pgoff_t index, gfp_t gfp); |
148 | |
149 | static inline struct folio *shmem_read_folio(struct address_space *mapping, |
150 | pgoff_t index) |
151 | { |
152 | return shmem_read_folio_gfp(mapping, index, gfp: mapping_gfp_mask(mapping)); |
153 | } |
154 | |
155 | static inline struct page *shmem_read_mapping_page( |
156 | struct address_space *mapping, pgoff_t index) |
157 | { |
158 | return shmem_read_mapping_page_gfp(mapping, index, |
159 | gfp_mask: mapping_gfp_mask(mapping)); |
160 | } |
161 | |
162 | static inline bool shmem_file(struct file *file) |
163 | { |
164 | if (!IS_ENABLED(CONFIG_SHMEM)) |
165 | return false; |
166 | if (!file || !file->f_mapping) |
167 | return false; |
168 | return shmem_mapping(mapping: file->f_mapping); |
169 | } |
170 | |
171 | /* |
172 | * If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages |
173 | * beyond i_size's notion of EOF, which fallocate has committed to reserving: |
174 | * which split_huge_page() must therefore not delete. This use of a single |
175 | * "fallocend" per inode errs on the side of not deleting a reservation when |
176 | * in doubt: there are plenty of cases when it preserves unreserved pages. |
177 | */ |
178 | static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof) |
179 | { |
180 | return max(eof, SHMEM_I(inode)->fallocend); |
181 | } |
182 | |
183 | extern bool shmem_charge(struct inode *inode, long pages); |
184 | extern void shmem_uncharge(struct inode *inode, long pages); |
185 | |
186 | #ifdef CONFIG_USERFAULTFD |
187 | #ifdef CONFIG_SHMEM |
188 | extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd, |
189 | struct vm_area_struct *dst_vma, |
190 | unsigned long dst_addr, |
191 | unsigned long src_addr, |
192 | uffd_flags_t flags, |
193 | struct folio **foliop); |
194 | #else /* !CONFIG_SHMEM */ |
195 | #define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \ |
196 | src_addr, flags, foliop) ({ BUG(); 0; }) |
197 | #endif /* CONFIG_SHMEM */ |
198 | #endif /* CONFIG_USERFAULTFD */ |
199 | |
200 | /* |
201 | * Used space is stored as unsigned 64-bit value in bytes but |
202 | * quota core supports only signed 64-bit values so use that |
203 | * as a limit |
204 | */ |
205 | #define SHMEM_QUOTA_MAX_SPC_LIMIT 0x7fffffffffffffffLL /* 2^63-1 */ |
206 | #define SHMEM_QUOTA_MAX_INO_LIMIT 0x7fffffffffffffffLL |
207 | |
208 | #ifdef CONFIG_TMPFS_QUOTA |
209 | extern const struct dquot_operations shmem_quota_operations; |
210 | extern struct quota_format_type shmem_quota_format; |
211 | #endif /* CONFIG_TMPFS_QUOTA */ |
212 | |
213 | #endif |
214 | |