680baacbca
a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
96 lines
2.9 KiB
C
96 lines
2.9 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/errno.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 nameidata;
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enum { MAX_NESTED_LINKS = 8 };
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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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* - dentry cache is untrusted; force a real lookup
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* - suppress terminal automount
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*/
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#define LOOKUP_FOLLOW 0x0001
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#define LOOKUP_DIRECTORY 0x0002
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#define LOOKUP_AUTOMOUNT 0x0004
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#define LOOKUP_PARENT 0x0010
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#define LOOKUP_REVAL 0x0020
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#define LOOKUP_RCU 0x0040
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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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#define LOOKUP_JUMPED 0x1000
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#define LOOKUP_ROOT 0x2000
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#define LOOKUP_EMPTY 0x4000
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extern int user_path_at(int, const char __user *, unsigned, struct path *);
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extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
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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 struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
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extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
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extern void done_path_create(struct path *, struct dentry *);
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extern struct dentry *kern_path_locked(const char *, struct path *);
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extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
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extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
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extern int follow_down_one(struct path *);
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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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extern void nd_jump_link(struct nameidata *nd, struct path *path);
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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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/**
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* retry_estale - determine whether the caller should retry an operation
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* @error: the error that would currently be returned
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* @flags: flags being used for next lookup attempt
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*
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* Check to see if the error code was -ESTALE, and then determine whether
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* to retry the call based on whether "flags" already has LOOKUP_REVAL set.
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*
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* Returns true if the caller should try the operation again.
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*/
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static inline bool
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retry_estale(const long error, const unsigned int flags)
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{
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return error == -ESTALE && !(flags & LOOKUP_REVAL);
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}
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#endif /* _LINUX_NAMEI_H */
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