introduce kern_path_mountpoint()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2013-09-08 20:18:44 -04:00
parent 197df04c74
commit 2d86465101
2 changed files with 25 additions and 11 deletions

View file

@ -2360,6 +2360,20 @@ path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags
return err;
}
static int
filename_mountpoint(int dfd, struct filename *s, struct path *path,
unsigned int flags)
{
int error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);
if (unlikely(error == -ECHILD))
error = path_mountpoint(dfd, s->name, path, flags);
if (unlikely(error == -ESTALE))
error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_REVAL);
if (likely(!error))
audit_inode(s, path->dentry, 0);
return error;
}
/**
* user_path_mountpoint_at - lookup a path from userland in order to umount it
* @dfd: directory file descriptor
@ -2380,23 +2394,22 @@ user_path_mountpoint_at(int dfd, const char __user *name, unsigned int flags,
{
struct filename *s = getname(name);
int error;
if (IS_ERR(s))
return PTR_ERR(s);
error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_RCU);
if (unlikely(error == -ECHILD))
error = path_mountpoint(dfd, s->name, path, flags);
if (unlikely(error == -ESTALE))
error = path_mountpoint(dfd, s->name, path, flags | LOOKUP_REVAL);
if (likely(!error))
audit_inode(s, path->dentry, 0);
error = filename_mountpoint(dfd, s, path, flags);
putname(s);
return error;
}
int
kern_path_mountpoint(int dfd, const char *name, struct path *path,
unsigned int flags)
{
struct filename s = {.name = name};
return filename_mountpoint(dfd, &s, path, flags);
}
EXPORT_SYMBOL(kern_path_mountpoint);
/*
* It's inline, so penalty for filesystems that don't use sticky bit is
* minimal.

View file

@ -70,6 +70,7 @@ extern struct dentry *kern_path_create(int, const char *, struct path *, unsigne
extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
extern void done_path_create(struct path *, struct dentry *);
extern struct dentry *kern_path_locked(const char *, struct path *);
extern int kern_path_mountpoint(int, const char *, struct path *, unsigned int);
extern struct dentry *lookup_one_len(const char *, struct dentry *, int);