+++ /dev/null
-/*
- * This Cplant(TM) source code is the property of Sandia National
- * Laboratories.
- *
- * This Cplant(TM) source code is copyrighted by Sandia National
- * Laboratories.
- *
- * The redistribution of this Cplant(TM) source code is subject to the
- * terms of the GNU Lesser General Public License
- * (see cit/LGPL or http://www.gnu.org/licenses/lgpl.html)
- *
- * Cplant(TM) Copyright 1998-2006 Sandia Corporation.
- * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
- * license for use of this work by or on behalf of the US Government.
- * Export of this program may require a license from the United States
- * Government.
- */
-
-/*
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Questions or comments about this library should be sent to:
- *
- * Lee Ward
- * Sandia National Laboratories, New Mexico
- * P.O. Box 5800
- * Albuquerque, NM 87185-1110
- *
- * lee@sandia.gov
- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-#include <assert.h>
-#include <unistd.h>
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/queue.h>
-
-#include "sysio.h"
-#include "mount.h"
-#include "inode.h"
-
-/*
- * Parse next component in path.
- */
-#ifndef AUTOMOUNT_FILE_NAME
-static
-#endif
-void
-_sysio_next_component(const char *path, struct qstr *name)
-{
- while (*path == PATH_SEPARATOR)
- path++;
- name->name = path;
- name->len = 0;
- name->hashval = 0;
- while (*path && *path != PATH_SEPARATOR) {
- name->hashval =
- 37 * name->hashval + *path++;
- name->len++;
- }
-}
-
-/*
- * Given parent, look up component.
- */
-static int
-lookup(struct pnode *parent,
- struct qstr *name,
- struct pnode **pnop,
- struct intent *intnt,
- const char *path,
- int check_permissions)
-{
- int err;
- struct pnode *pno;
-
- if (!parent->p_base->pb_ino)
- return -ENOTDIR;
-
- /*
- * Sometimes we don't want to check permissions. At initialization
- * time, for instance.
- */
- if (check_permissions) {
- err = _sysio_permitted(parent, X_OK);
- if (err)
- return err;
- }
-
- /*
- * Short-circuit `.' and `..'; We don't cache those.
- */
- pno = NULL;
- if (name->len == 1 && name->name[0] == '.')
- pno = parent;
- else if (name->len == 2 && name->name[0] == '.' && name->name[1] == '.')
- pno = parent->p_parent;
- if (pno)
- P_REF(pno);
- else {
- /*
- * Get cache entry then.
- */
- err = _sysio_p_find_alias(parent, name, &pno);
- if (err)
- return err;
- }
-
- /*
- * While covered, move to the covering node.
- */
- while (pno->p_cover && pno->p_cover != pno) {
- struct pnode *cover;
-
- cover = pno->p_cover;
- P_REF(cover);
- P_RELE(pno);
- pno = cover;
- }
-
- *pnop = pno;
-
- /*
- * (Re)validate the pnode.
- */
- err = _sysio_p_validate(pno, intnt, path);
- if (err)
- return err;
-
- return 0;
-}
-
-/*
- * The meat. Walk an absolute or relative path, looking up each
- * component. Various flags in the nameidata argument govern actions
- * and return values/state. They are:
- *
- * ND_NOFOLLOW symbolic links are not followed
- * ND_NEGOK if terminal/leaf does not exist, return
- * path node (alias) anyway.
- * ND_NOPERMCHECK do not check permissions
- */
-int
-_sysio_path_walk(struct pnode *parent, struct nameidata *nd)
-{
- int err;
- const char *path;
- struct qstr this, next;
- struct inode *ino;
-
- /*
- * NULL path?
- */
- if (!nd->nd_path)
- return -EFAULT;
-
- /*
- * Empty path?
- */
- if (!*nd->nd_path)
- return -ENOENT;
-
- /*
- * Leading slash?
- */
- if (*nd->nd_path == PATH_SEPARATOR) {
- /*
- * Make parent the root of the name space.
- */
- parent = nd->nd_root;
- }
-
-#ifdef DEFER_INIT_CWD
- if (!parent) {
- const char *icwd;
-
- if (!_sysio_init_cwd && !nd->nd_root)
- abort();
-
- /*
- * Finally have to set the current working directory. We can
- * not tolerate errors here or else risk leaving the process
- * in a very unexpected location. We abort then unless all goes
- * well.
- */
- icwd = _sysio_init_cwd;
- _sysio_init_cwd = NULL;
- parent = nd->nd_root;
- if (!parent)
- abort();
- (void )_sysio_namei(nd->nd_root, icwd, 0, NULL, &parent);
- if (_sysio_p_chdir(parent) != 0)
- abort();
- }
-#endif
-
- /*
- * (Re)Validate the parent.
- */
- err = _sysio_p_validate(parent, NULL, NULL);
- if (err)
- return err;
-
- /*
- * Prime everything for the loop. Will need another reference to the
- * initial directory. It'll be dropped later.
- */
- nd->nd_pno = parent;
- P_REF(nd->nd_pno);
- _sysio_next_component(nd->nd_path, &next);
- path = next.name;
- parent = NULL;
- err = 0;
-
- /*
- * Derecurse the path tree-walk.
- */
- for (;;) {
- ino = nd->nd_pno->p_base->pb_ino;
- if (S_ISLNK(ino->i_stbuf.st_mode) &&
- (next.len || !(nd->nd_flags & ND_NOFOLLOW))) {
- char *lpath;
- ssize_t cc;
- struct nameidata nameidata;
-
- if (nd->nd_slicnt >= MAX_SYMLINK) {
- err = -ELOOP;
- break;
- }
-
- /*
- * Follow symbolic link.
- */
- lpath = malloc(MAXPATHLEN + 1);
- if (!lpath) {
- err = -ENOMEM;
- break;
- }
- cc =
- ino->i_ops.inop_readlink(nd->nd_pno,
- lpath,
- MAXPATHLEN);
- if (cc < 0) {
- free(lpath);
- err = (int )cc;
- break;
- }
- lpath[cc] = '\0'; /* NUL term */
- /*
- * Handle symbolic links with recursion. Yuck!
- * Pass the NULL intent for recursive symlink
- * except the last component.
- */
- ND_INIT(&nameidata,
- nd->nd_flags,
- lpath,
- nd->nd_root,
- !next.len ? nd->nd_intent : NULL);
- nameidata.nd_slicnt = nd->nd_slicnt + 1;
- err =
- _sysio_path_walk(nd->nd_pno->p_parent, &nameidata);
- free(lpath);
- if (err)
- break;
- P_RELE(nd->nd_pno);
- nd->nd_pno = nameidata.nd_pno;
- ino = nd->nd_pno->p_base->pb_ino;
- }
-#ifdef AUTOMOUNT_FILE_NAME
- else if (ino &&
- S_ISDIR(ino->i_stbuf.st_mode) &&
- (nd->nd_pno->p_mount->mnt_flags & MOUNT_F_AUTO) &&
- nd->nd_amcnt < MAX_MOUNT_DEPTH &&
- ino->i_stbuf.st_mode & S_ISUID) {
- struct pnode *pno;
-
- /*
- * We're committed to a lookup. It's time to see if
- * we're going to do it in an automount-point and
- * arrange the mount if so.
- */
- assert(!nd->nd_pno->p_cover);
- err =
- lookup(nd->nd_pno,
- &_sysio_mount_file_name,
- &pno,
- NULL,
- NULL,
- 1);
- if (pno)
- P_RELE(pno);
- if (!err && _sysio_automount(pno) == 0) {
- struct pnode *root;
-
- /*
- * All went well. Need to switch
- * parent pno and ino to the
- * root of the newly mounted sub-tree.
- *
- * NB:
- * We don't recurseively retry these
- * things. It's OK to have the new root
- * be an automount-point but it's going
- * to take another lookup to accomplish it.
- * The alternative could get us into an
- * infinite loop.
- */
- root = nd->nd_pno->p_cover;
- assert(root);
- P_RELE(nd->nd_pno);
- nd->nd_pno = root;
-#if 0
- P_REF(nd->nd_pno);
-#endif
- ino = nd->nd_pno->p_base->pb_ino;
- assert(ino);
-
- /*
- * Must send the intent-path again.
- */
- path = nd->nd_path;
- nd->nd_amcnt++;
-
- /*
- * Must go back top and retry with this
- * new pnode as parent.
- */
- continue;
- }
- err = 0; /* it never happened */
- }
-#endif
-
- /*
- * Set up for next component.
- */
- this = next;
- if (path)
- path = this.name;
- if (!this.len)
- break;
- if (!ino) {
- /*
- * Should only be here if final component was
- * target of a symlink.
- */
- nd->nd_path = this.name + this.len;
- err = -ENOENT;
- break;
- }
- nd->nd_path = this.name + this.len;
- _sysio_next_component(nd->nd_path, &next);
- parent = nd->nd_pno;
- nd->nd_pno = NULL;
-
- /*
- * Parent must be a directory.
- */
- if (ino && !S_ISDIR(ino->i_stbuf.st_mode)) {
- err = -ENOTDIR;
- break;
- }
-
- /*
- * The extra path arg is passed only on the first lookup in the
- * walk as we cross into each file system, anew. The intent is
- * passed both on the first lookup and when trying to look up
- * the final component -- Of the original path, not on the
- * file system.
- *
- * Confused? Me too and I came up with this weirdness. It's
- * hints to the file system drivers. Read on.
- *
- * The first lookup will give everything one needs to ready
- * everything for the entire operation before the path is
- * walked. The file system driver knows it's the first lookup
- * in the walk because it has both the path and the intent.
- *
- * Alternatively, one could split the duties; The first lookup
- * can be used to prime the file system inode cache with the
- * interior nodes we'll want in the path-walk. Then, when
- * looking up the last component, ready everything for the
- * operations(s) to come. The file system driver knows it's
- * the last lookup in the walk because it has the intent,
- * again, but without the path.
- *
- * One special case; If we were asked to look up a single
- * component, we treat it as the last component. The file
- * system driver never sees the extra path argument. It should
- * be noted that the driver always has the fully qualified
- * path, on the target file system, available to it for any
- * node it is looking up, including the last, via the base
- * path node and it's ancestor chain.
- */
- err =
- lookup(parent,
- &this,
- &nd->nd_pno,
- (path || !next.len)
- ? nd->nd_intent
- : NULL,
- (path && next.len) ? path : NULL,
- !(nd->nd_flags & ND_NOPERMCHECK));
- if (err) {
- if (err == -ENOENT &&
- !next.len &&
- (nd->nd_flags & ND_NEGOK))
- err = 0;
- break;
- }
- path = NULL; /* Stop that! */
- if ((parent->p_mount->mnt_fs !=
- nd->nd_pno->p_mount->mnt_fs)) {
- /*
- * Crossed into a new fs. We'll want the next lookup
- * to include the path again.
- */
- path = nd->nd_path;
- }
-
- /*
- * Release the parent.
- */
- P_RELE(parent);
- parent = NULL;
- }
-
- /*
- * Trailing separators cause us to break from the loop with
- * a parent set but no pnode. Check for that.
- */
- if (!nd->nd_pno) {
- nd->nd_pno = parent;
- parent = NULL;
- /*
- * Make sure the last processed component was a directory. The
- * trailing slashes are illegal behind anything else.
- */
- if (!(err ||
- S_ISDIR(nd->nd_pno->p_base->pb_ino->i_stbuf.st_mode)))
- err = -ENOTDIR;
- }
-
- /*
- * Drop reference to parent if set. Either we have a dup of the original
- * parent or an intermediate reference.
- */
- if (parent)
- P_RELE(parent);
-
- /*
- * On error, we will want to drop our reference to the current
- * path node if at end.
- */
- if (err && nd->nd_pno) {
- P_RELE(nd->nd_pno);
- nd->nd_pno = NULL;
- }
-
- return err;
-}
-
-#ifdef CPLANT_YOD
-/*
- * for backward compatibility w/protocol switch
- * remove everything up to the first ':'
- * fortran libs prepend cwd to path, so not much choice
- */
-#define STRIP_PREFIX(p) strchr(p,':') ? strchr(p,':')+1 : p
-#else
-#define STRIP_PREFIX(p) p
-#endif
-
-/*
- * Expanded form of the path-walk routine, with the common arguments, builds
- * the nameidata bundle and calls path-walk.
- */
-int
-_sysio_namei(struct pnode *parent,
- const char *path,
- unsigned flags,
- struct intent *intnt,
- struct pnode **pnop)
-{
- struct nameidata nameidata;
- int err;
-
- ND_INIT(&nameidata, flags, STRIP_PREFIX(path), _sysio_root, intnt);
- err = _sysio_path_walk(parent, &nameidata);
- if (!err)
- *pnop = nameidata.nd_pno;
- return err;
-}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff