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 }; 51 52 /* +1 to avoid triggering overflow warning when negating it */ 53 #define KN_DEACTIVATED_BIAS (INT_MIN + 1) 54 55 /* KERNFS_TYPE_MASK and types are defined in include/linux/kernfs.h */ 56 57 /** 58 * kernfs_root - find out the kernfs_root a kernfs_node belongs to 59 * @kn: kernfs_node of interest 60 * 61 * Return the kernfs_root @kn belongs to. 62 */ 63 static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn) 64 { 65 /* if parent exists, it's always a dir; otherwise, @sd is a dir */ 66 if (kn->parent) 67 kn = kn->parent; 68 return kn->dir.root; 69 } 70 71 /* 72 * mount.c 73 */ 74 struct kernfs_super_info { 75 struct super_block *sb; 76 77 /* 78 * The root associated with this super_block. Each super_block is 79 * identified by the root and ns it's associated with. 80 */ 81 struct kernfs_root *root; 82 83 /* 84 * Each sb is associated with one namespace tag, currently the 85 * network namespace of the task which mounted this kernfs 86 * instance. If multiple tags become necessary, make the following 87 * an array and compare kernfs_node tag against every entry. 88 */ 89 const void *ns; 90 91 /* anchored at kernfs_root->supers, protected by kernfs_rwsem */ 92 struct list_head node; 93 }; 94 #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info)) 95 96 static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry) 97 { 98 if (d_really_is_negative(dentry)) 99 return NULL; 100 return d_inode(dentry)->i_private; 101 } 102 103 static inline void kernfs_set_rev(struct kernfs_node *parent, 104 struct dentry *dentry) 105 { 106 dentry->d_time = parent->dir.rev; 107 } 108 109 static inline void kernfs_inc_rev(struct kernfs_node *parent) 110 { 111 parent->dir.rev++; 112 } 113 114 static inline bool kernfs_dir_changed(struct kernfs_node *parent, 115 struct dentry *dentry) 116 { 117 if (parent->dir.rev != dentry->d_time) 118 return true; 119 return false; 120 } 121 122 extern const struct super_operations kernfs_sops; 123 extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache; 124 125 /* 126 * inode.c 127 */ 128 extern const struct xattr_handler *kernfs_xattr_handlers[]; 129 void kernfs_evict_inode(struct inode *inode); 130 int kernfs_iop_permission(struct user_namespace *mnt_userns, 131 struct inode *inode, int mask); 132 int kernfs_iop_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, 133 struct iattr *iattr); 134 int kernfs_iop_getattr(struct user_namespace *mnt_userns, 135 const struct path *path, struct kstat *stat, 136 u32 request_mask, unsigned int query_flags); 137 ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size); 138 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr); 139 140 /* 141 * dir.c 142 */ 143 extern const struct dentry_operations kernfs_dops; 144 extern const struct file_operations kernfs_dir_fops; 145 extern const struct inode_operations kernfs_dir_iops; 146 147 struct kernfs_node *kernfs_get_active(struct kernfs_node *kn); 148 void kernfs_put_active(struct kernfs_node *kn); 149 int kernfs_add_one(struct kernfs_node *kn); 150 struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, 151 const char *name, umode_t mode, 152 kuid_t uid, kgid_t gid, 153 unsigned flags); 154 155 /* 156 * file.c 157 */ 158 extern const struct file_operations kernfs_file_fops; 159 160 bool kernfs_should_drain_open_files(struct kernfs_node *kn); 161 void kernfs_drain_open_files(struct kernfs_node *kn); 162 163 /* 164 * symlink.c 165 */ 166 extern const struct inode_operations kernfs_symlink_iops; 167 168 /* 169 * kernfs locks 170 */ 171 extern struct kernfs_global_locks *kernfs_locks; 172 #endif /* __KERNFS_INTERNAL_H */ 173