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