Commit ef55d917 authored by Al Viro's avatar Al Viro
Browse files

path_init(): set nd->inode earlier in cwd-relative case 



that allows to kill the recheck of nd->seq on the way out in
this case, and this check on the way out is left only for
absolute pathnames.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9e6697e2

fs/namei.c

+12 −10
Original line number Diff line number Diff line
@@ -2028,6 +2028,15 @@ static const char *path_init(struct nameidata *nd, unsigned flags) 
			path_get(&nd->root);

			nd->path = nd->root;

		}

		nd->inode = nd->path.dentry->d_inode;

		if (!(flags & LOOKUP_RCU))

			return s;

		if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))

			return s;

		if (!(nd->flags & LOOKUP_ROOT))

			nd->root.mnt = NULL;

		rcu_read_unlock();

		return ERR_PTR(-ECHILD);

	} else if (nd->dfd == AT_FDCWD) {

		if (flags & LOOKUP_RCU) {

			struct fs_struct *fs = current->fs;
@@ -2038,11 +2047,14 @@ static const char *path_init(struct nameidata *nd, unsigned flags) 
			do {

				seq = read_seqcount_begin(&fs->seq);

				nd->path = fs->pwd;

				nd->inode = nd->path.dentry->d_inode;

				nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);

			} while (read_seqcount_retry(&fs->seq, seq));

		} else {

			get_fs_pwd(current->fs, &nd->path);

			nd->inode = nd->path.dentry->d_inode;

		}

		return s;

	} else {

		/* Caller must check execute permissions on the starting path component */

		struct fd f = fdget_raw(nd->dfd);
@@ -2072,16 +2084,6 @@ static const char *path_init(struct nameidata *nd, unsigned flags) 
		fdput(f);

		return s;

	}



	nd->inode = nd->path.dentry->d_inode;

	if (!(flags & LOOKUP_RCU))

		return s;

	if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))

		return s;

	if (!(nd->flags & LOOKUP_ROOT))

		nd->root.mnt = NULL;

	rcu_read_unlock();

	return ERR_PTR(-ECHILD);

}



static const char *trailing_symlink(struct nameidata *nd)