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 #include <linux/android_vendor.h>
14
15 /* inode in-kernel data */
16
17 #ifdef CONFIG_TMPFS_QUOTA
18 #define SHMEM_MAXQUOTAS 2
19 #endif
20
21 struct shmem_inode_info {
22 spinlock_t lock;
23 unsigned int seals; /* shmem seals */
24 unsigned long flags;
25 unsigned long alloced; /* data pages alloced to file */
26 unsigned long swapped; /* subtotal assigned to swap */
27 union {
28 struct offset_ctx dir_offsets; /* stable directory offsets */
29 struct {
30 struct list_head shrinklist; /* shrinkable hpage inodes */
31 struct list_head swaplist; /* chain of maybes on swap */
32 };
33 };
34 struct timespec64 i_crtime; /* file creation time */
35 struct shared_policy policy; /* NUMA memory alloc policy */
36 struct simple_xattrs xattrs; /* list of xattrs */
37 pgoff_t fallocend; /* highest fallocate endindex */
38 unsigned int fsflags; /* for FS_IOC_[SG]ETFLAGS */
39 atomic_t stop_eviction; /* hold when working on inode */
40 #ifdef CONFIG_TMPFS_QUOTA
41 struct dquot __rcu *i_dquot[MAXQUOTAS];
42 #endif
43 struct inode vfs_inode;
44
45 ANDROID_VENDOR_DATA(1);
46 };
47
48 #define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE
49 #define SHMEM_FL_USER_MODIFIABLE \
50 (FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
51 #define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL)
52
53 struct shmem_quota_limits {
54 qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */
55 qsize_t usrquota_ihardlimit; /* Default user quota inode hard limit */
56 qsize_t grpquota_bhardlimit; /* Default group quota block hard limit */
57 qsize_t grpquota_ihardlimit; /* Default group quota inode hard limit */
58 };
59
60 struct shmem_sb_info {
61 unsigned long max_blocks; /* How many blocks are allowed */
62 struct percpu_counter used_blocks; /* How many are allocated */
63 unsigned long max_inodes; /* How many inodes are allowed */
64 unsigned long free_ispace; /* How much ispace left for allocation */
65 raw_spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
66 umode_t mode; /* Mount mode for root directory */
67 unsigned char huge; /* Whether to try for hugepages */
68 kuid_t uid; /* Mount uid for root directory */
69 kgid_t gid; /* Mount gid for root directory */
70 bool full_inums; /* If i_ino should be uint or ino_t */
71 bool noswap; /* ignores VM reclaim / swap requests */
72 ino_t next_ino; /* The next per-sb inode number to use */
73 ino_t __percpu *ino_batch; /* The next per-cpu inode number to use */
74 struct mempolicy *mpol; /* default memory policy for mappings */
75 spinlock_t shrinklist_lock; /* Protects shrinklist */
76 struct list_head shrinklist; /* List of shinkable inodes */
77 unsigned long shrinklist_len; /* Length of shrinklist */
78 struct shmem_quota_limits qlimits; /* Default quota limits */
79 };
80
SHMEM_I(struct inode * inode)81 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
82 {
83 return container_of(inode, struct shmem_inode_info, vfs_inode);
84 }
85
86 /*
87 * Functions in mm/shmem.c called directly from elsewhere:
88 */
89 extern const struct fs_parameter_spec shmem_fs_parameters[];
90 extern void shmem_init(void);
91 extern int shmem_init_fs_context(struct fs_context *fc);
92 extern struct file *shmem_file_setup(const char *name,
93 loff_t size, unsigned long flags);
94 extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
95 unsigned long flags);
96 extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt,
97 const char *name, loff_t size, unsigned long flags);
98 extern int shmem_zero_setup(struct vm_area_struct *);
99 extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
100 unsigned long len, unsigned long pgoff, unsigned long flags);
101 extern int shmem_lock(struct file *file, int lock, struct ucounts *ucounts);
102 #ifdef CONFIG_SHMEM
103 bool shmem_mapping(struct address_space *mapping);
104 #else
shmem_mapping(struct address_space * mapping)105 static inline bool shmem_mapping(struct address_space *mapping)
106 {
107 return false;
108 }
109 #endif /* CONFIG_SHMEM */
110 extern void shmem_unlock_mapping(struct address_space *mapping);
111 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
112 pgoff_t index, gfp_t gfp_mask);
113 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
114 int shmem_unuse(unsigned int type);
115
116 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
117 unsigned long shmem_allowable_huge_orders(struct inode *inode,
118 struct vm_area_struct *vma, pgoff_t index,
119 loff_t write_end, bool shmem_huge_force);
120 #else
shmem_allowable_huge_orders(struct inode * inode,struct vm_area_struct * vma,pgoff_t index,loff_t write_end,bool shmem_huge_force)121 static inline unsigned long shmem_allowable_huge_orders(struct inode *inode,
122 struct vm_area_struct *vma, pgoff_t index,
123 loff_t write_end, bool shmem_huge_force)
124 {
125 return 0;
126 }
127 #endif
128
129 #ifdef CONFIG_SHMEM
130 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
131 #else
shmem_swap_usage(struct vm_area_struct * vma)132 static inline unsigned long shmem_swap_usage(struct vm_area_struct *vma)
133 {
134 return 0;
135 }
136 #endif
137 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
138 pgoff_t start, pgoff_t end);
139
140 /* Flag allocation requirements to shmem_get_folio */
141 enum sgp_type {
142 SGP_READ, /* don't exceed i_size, don't allocate page */
143 SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */
144 SGP_CACHE, /* don't exceed i_size, may allocate page */
145 SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
146 SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
147 };
148
149 int shmem_get_folio(struct inode *inode, pgoff_t index, loff_t write_end,
150 struct folio **foliop, enum sgp_type sgp);
151 struct folio *shmem_read_folio_gfp(struct address_space *mapping,
152 pgoff_t index, gfp_t gfp);
153
shmem_read_folio(struct address_space * mapping,pgoff_t index)154 static inline struct folio *shmem_read_folio(struct address_space *mapping,
155 pgoff_t index)
156 {
157 return shmem_read_folio_gfp(mapping, index, mapping_gfp_mask(mapping));
158 }
159
shmem_read_mapping_page(struct address_space * mapping,pgoff_t index)160 static inline struct page *shmem_read_mapping_page(
161 struct address_space *mapping, pgoff_t index)
162 {
163 return shmem_read_mapping_page_gfp(mapping, index,
164 mapping_gfp_mask(mapping));
165 }
166
shmem_file(struct file * file)167 static inline bool shmem_file(struct file *file)
168 {
169 if (!IS_ENABLED(CONFIG_SHMEM))
170 return false;
171 if (!file || !file->f_mapping)
172 return false;
173 return shmem_mapping(file->f_mapping);
174 }
175
176 /*
177 * If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages
178 * beyond i_size's notion of EOF, which fallocate has committed to reserving:
179 * which split_huge_page() must therefore not delete. This use of a single
180 * "fallocend" per inode errs on the side of not deleting a reservation when
181 * in doubt: there are plenty of cases when it preserves unreserved pages.
182 */
shmem_fallocend(struct inode * inode,pgoff_t eof)183 static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof)
184 {
185 return max(eof, SHMEM_I(inode)->fallocend);
186 }
187
188 extern bool shmem_charge(struct inode *inode, long pages);
189 extern void shmem_uncharge(struct inode *inode, long pages);
190
191 #ifdef CONFIG_USERFAULTFD
192 #ifdef CONFIG_SHMEM
193 extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
194 struct vm_area_struct *dst_vma,
195 unsigned long dst_addr,
196 unsigned long src_addr,
197 uffd_flags_t flags,
198 struct folio **foliop);
199 #else /* !CONFIG_SHMEM */
200 #define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \
201 src_addr, flags, foliop) ({ BUG(); 0; })
202 #endif /* CONFIG_SHMEM */
203 #endif /* CONFIG_USERFAULTFD */
204
205 /*
206 * Used space is stored as unsigned 64-bit value in bytes but
207 * quota core supports only signed 64-bit values so use that
208 * as a limit
209 */
210 #define SHMEM_QUOTA_MAX_SPC_LIMIT 0x7fffffffffffffffLL /* 2^63-1 */
211 #define SHMEM_QUOTA_MAX_INO_LIMIT 0x7fffffffffffffffLL
212
213 #ifdef CONFIG_TMPFS_QUOTA
214 extern const struct dquot_operations shmem_quota_operations;
215 extern struct quota_format_type shmem_quota_format;
216 #endif /* CONFIG_TMPFS_QUOTA */
217
218 #endif
219