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 *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 extern const struct address_space_operations shmem_aops; 101 static inline bool shmem_mapping(struct address_space *mapping) 102 { 103 return mapping->a_ops == &shmem_aops; 104 } 105 #else 106 static inline bool shmem_mapping(struct address_space *mapping) 107 { 108 return false; 109 } 110 #endif /* CONFIG_SHMEM */ 111 extern void shmem_unlock_mapping(struct address_space *mapping); 112 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, 113 pgoff_t index, gfp_t gfp_mask); 114 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); 115 int shmem_unuse(unsigned int type); 116 117 extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, 118 struct mm_struct *mm, unsigned long vm_flags); 119 #ifdef CONFIG_SHMEM 120 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); 121 #else 122 static inline unsigned long shmem_swap_usage(struct vm_area_struct *vma) 123 { 124 return 0; 125 } 126 #endif 127 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping, 128 pgoff_t start, pgoff_t end); 129 130 /* Flag allocation requirements to shmem_get_folio */ 131 enum sgp_type { 132 SGP_READ, /* don't exceed i_size, don't allocate page */ 133 SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */ 134 SGP_CACHE, /* don't exceed i_size, may allocate page */ 135 SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */ 136 SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */ 137 }; 138 139 int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop, 140 enum sgp_type sgp); 141 struct folio *shmem_read_folio_gfp(struct address_space *mapping, 142 pgoff_t index, gfp_t gfp); 143 144 static inline struct folio *shmem_read_folio(struct address_space *mapping, 145 pgoff_t index) 146 { 147 return shmem_read_folio_gfp(mapping, index, mapping_gfp_mask(mapping)); 148 } 149 150 static inline struct page *shmem_read_mapping_page( 151 struct address_space *mapping, pgoff_t index) 152 { 153 return shmem_read_mapping_page_gfp(mapping, index, 154 mapping_gfp_mask(mapping)); 155 } 156 157 static inline bool shmem_file(struct file *file) 158 { 159 if (!IS_ENABLED(CONFIG_SHMEM)) 160 return false; 161 if (!file || !file->f_mapping) 162 return false; 163 return shmem_mapping(file->f_mapping); 164 } 165 166 /* 167 * If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages 168 * beyond i_size's notion of EOF, which fallocate has committed to reserving: 169 * which split_huge_page() must therefore not delete. This use of a single 170 * "fallocend" per inode errs on the side of not deleting a reservation when 171 * in doubt: there are plenty of cases when it preserves unreserved pages. 172 */ 173 static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof) 174 { 175 return max(eof, SHMEM_I(inode)->fallocend); 176 } 177 178 extern bool shmem_charge(struct inode *inode, long pages); 179 extern void shmem_uncharge(struct inode *inode, long pages); 180 181 #ifdef CONFIG_USERFAULTFD 182 #ifdef CONFIG_SHMEM 183 extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd, 184 struct vm_area_struct *dst_vma, 185 unsigned long dst_addr, 186 unsigned long src_addr, 187 uffd_flags_t flags, 188 struct folio **foliop); 189 #else /* !CONFIG_SHMEM */ 190 #define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \ 191 src_addr, flags, foliop) ({ BUG(); 0; }) 192 #endif /* CONFIG_SHMEM */ 193 #endif /* CONFIG_USERFAULTFD */ 194 195 /* 196 * Used space is stored as unsigned 64-bit value in bytes but 197 * quota core supports only signed 64-bit values so use that 198 * as a limit 199 */ 200 #define SHMEM_QUOTA_MAX_SPC_LIMIT 0x7fffffffffffffffLL /* 2^63-1 */ 201 #define SHMEM_QUOTA_MAX_INO_LIMIT 0x7fffffffffffffffLL 202 203 #ifdef CONFIG_TMPFS_QUOTA 204 extern const struct dquot_operations shmem_quota_operations; 205 extern struct quota_format_type shmem_quota_format; 206 #endif /* CONFIG_TMPFS_QUOTA */ 207 208 #endif 209