832b6af198
By teaching sysfs_revalidate to hide a dentry for a sysfs_dirent if the sysfs_dirent has been renamed, and by teaching sysfs_lookup to return the original dentry if the sysfs dirent has been renamed. I can show the results of renames correctly without having to update the dcache during the directory rename. This massively simplifies the rename logic allowing a lot of weird sysfs special cases to be removed along with a lot of now unnecesary helper code. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
101 lines
2.6 KiB
C
101 lines
2.6 KiB
C
#ifndef _LINUX_NAMEI_H
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#define _LINUX_NAMEI_H
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#include <linux/dcache.h>
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#include <linux/linkage.h>
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#include <linux/path.h>
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struct vfsmount;
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struct open_intent {
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int flags;
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int create_mode;
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struct file *file;
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};
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enum { MAX_NESTED_LINKS = 8 };
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struct nameidata {
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struct path path;
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struct qstr last;
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struct path root;
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unsigned int flags;
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int last_type;
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unsigned depth;
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char *saved_names[MAX_NESTED_LINKS + 1];
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/* Intent data */
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union {
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struct open_intent open;
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} intent;
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};
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/*
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* Type of the last component on LOOKUP_PARENT
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*/
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enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
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/*
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* The bitmask for a lookup event:
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* - follow links at the end
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* - require a directory
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* - ending slashes ok even for nonexistent files
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* - internal "there are more path components" flag
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* - locked when lookup done with dcache_lock held
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* - dentry cache is untrusted; force a real lookup
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*/
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#define LOOKUP_FOLLOW 1
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#define LOOKUP_DIRECTORY 2
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#define LOOKUP_CONTINUE 4
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#define LOOKUP_PARENT 16
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#define LOOKUP_REVAL 64
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/*
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* Intent data
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*/
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#define LOOKUP_OPEN 0x0100
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#define LOOKUP_CREATE 0x0200
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#define LOOKUP_EXCL 0x0400
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#define LOOKUP_RENAME_TARGET 0x0800
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extern int user_path_at(int, const char __user *, unsigned, struct path *);
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#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
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#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
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#define user_path_dir(name, path) \
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user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
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extern int kern_path(const char *, unsigned, struct path *);
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extern int path_lookup(const char *, unsigned, struct nameidata *);
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extern int vfs_path_lookup(struct dentry *, struct vfsmount *,
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const char *, unsigned int, struct nameidata *);
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extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
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int (*open)(struct inode *, struct file *));
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extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
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extern void release_open_intent(struct nameidata *);
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extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
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extern int follow_down(struct path *);
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extern int follow_up(struct path *);
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extern struct dentry *lock_rename(struct dentry *, struct dentry *);
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extern void unlock_rename(struct dentry *, struct dentry *);
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static inline void nd_set_link(struct nameidata *nd, char *path)
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{
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nd->saved_names[nd->depth] = path;
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}
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static inline char *nd_get_link(struct nameidata *nd)
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{
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return nd->saved_names[nd->depth];
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}
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static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
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{
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((char *) name)[min(len, maxlen)] = '\0';
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}
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#endif /* _LINUX_NAMEI_H */
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