1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * fs/kernfs/kernfs-internal.h - kernfs internal header file 4 * 5 * Copyright (c) 2001-3 Patrick Mochel 6 * Copyright (c) 2007 SUSE Linux Products GmbH 7 * Copyright (c) 2007, 2013 Tejun Heo <teheo@suse.de> 8 */ 9 10 #ifndef __KERNFS_INTERNAL_H 11 #define __KERNFS_INTERNAL_H 12 13 #include <linux/lockdep.h> 14 #include <linux/fs.h> 15 #include <linux/mutex.h> 16 #include <linux/rwsem.h> 17 #include <linux/xattr.h> 18 19 #include <linux/kernfs.h> 20 #include <linux/fs_context.h> 21 22 struct kernfs_iattrs { 23 kuid_t ia_uid; 24 kgid_t ia_gid; 25 struct timespec64 ia_atime; 26 struct timespec64 ia_mtime; 27 struct timespec64 ia_ctime; 28 29 struct simple_xattrs xattrs; 30 atomic_t nr_user_xattrs; 31 atomic_t user_xattr_size; 32 }; 33 34 struct kernfs_root { 35 /* published fields */ 36 struct kernfs_node *kn; 37 unsigned int flags; /* KERNFS_ROOT_* flags */ 38 39 /* private fields, do not use outside kernfs proper */ 40 struct idr ino_idr; 41 u32 last_id_lowbits; 42 u32 id_highbits; 43 struct kernfs_syscall_ops *syscall_ops; 44 45 /* list of kernfs_super_info of this root, protected by kernfs_rwsem */ 46 struct list_head supers; 47 48 wait_queue_head_t deactivate_waitq; 49 struct rw_semaphore kernfs_rwsem; 50 struct rw_semaphore kernfs_iattr_rwsem; 51 struct rw_semaphore kernfs_supers_rwsem; 52 }; 53 54 /* +1 to avoid triggering overflow warning when negating it */ 55 #define KN_DEACTIVATED_BIAS (INT_MIN + 1) 56 57 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */ 58 59 /** 60 * kernfs_root - find out the kernfs_root a kernfs_node belongs to 61 * @kn: kernfs_node of interest 62 * 63 * Return: the kernfs_root @kn belongs to. 64 */ 65 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn) 66 { 67 /* if parent exists, it's always a dir; otherwise, @sd is a dir */ 68 if (kn->parent) 69 kn = kn->parent; 70 return kn->dir.root; 71 } 72 73 /* 74 * mount.c 75 */ 76 struct kernfs_super_info { 77 struct super_block *sb; 78 79 /* 80 * The root associated with this super_block. Each super_block is 81 * identified by the root and ns it's associated with. 82 */ 83 struct kernfs_root *root; 84 85 /* 86 * Each sb is associated with one namespace tag, currently the 87 * network namespace of the task which mounted this kernfs 88 * instance. If multiple tags become necessary, make the following 89 * an array and compare kernfs_node tag against every entry. 90 */ 91 const void *ns; 92 93 /* anchored at kernfs_root->supers, protected by kernfs_rwsem */ 94 struct list_head node; 95 }; 96 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info)) 97 98 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry) 99 { 100 if (d_really_is_negative(dentry)) 101 return NULL; 102 return d_inode(dentry)->i_private; 103 } 104 105 static inline void kernfs_set_rev(struct kernfs_node *parent, 106 struct dentry *dentry) 107 { 108 dentry->d_time = parent->dir.rev; 109 } 110 111 static inline void kernfs_inc_rev(struct kernfs_node *parent) 112 { 113 parent->dir.rev++; 114 } 115 116 static inline bool kernfs_dir_changed(struct kernfs_node *parent, 117 struct dentry *dentry) 118 { 119 if (parent->dir.rev != dentry->d_time) 120 return true; 121 return false; 122 } 123 124 extern const struct super_operations kernfs_sops; 125 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache; 126 127 /* 128 * inode.c 129 */ 130 extern const struct xattr_handler * const kernfs_xattr_handlers[]; 131 void kernfs_evict_inode(struct inode *inode); 132 int kernfs_iop_permission(struct mnt_idmap *idmap, 133 struct inode *inode, int mask); 134 int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry, 135 struct iattr *iattr); 136 int kernfs_iop_getattr(struct mnt_idmap *idmap, 137 const struct path *path, struct kstat *stat, 138 u32 request_mask, unsigned int query_flags); 139 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size); 140 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr); 141 142 /* 143 * dir.c 144 */ 145 extern const struct dentry_operations kernfs_dops; 146 extern const struct file_operations kernfs_dir_fops; 147 extern const struct inode_operations kernfs_dir_iops; 148 149 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn); 150 void kernfs_put_active(struct kernfs_node *kn); 151 int kernfs_add_one(struct kernfs_node *kn); 152 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, 153 const char *name, umode_t mode, 154 kuid_t uid, kgid_t gid, 155 unsigned flags); 156 157 /* 158 * file.c 159 */ 160 extern const struct file_operations kernfs_file_fops; 161 162 bool kernfs_should_drain_open_files(struct kernfs_node *kn); 163 void kernfs_drain_open_files(struct kernfs_node *kn); 164 165 /* 166 * symlink.c 167 */ 168 extern const struct inode_operations kernfs_symlink_iops; 169 170 /* 171 * kernfs locks 172 */ 173 extern struct kernfs_global_locks *kernfs_locks; 174 #endif /* __KERNFS_INTERNAL_H */ 175