/*
- * linux/fs/ext2/symlink.c
+ * GPL HEADER START
*
- * This code is issued under the GNU General Public License.
- * See the file COPYING in this distribution
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * Copyright (C) 1992, 1993, 1994, 1995
- * Remy Card (card@masi.ibp.fr)
- * Laboratoire MASI - Institut Blaise Pascal
- * Universite Pierre et Marie Curie (Paris VI)
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
*
- * Copyright (C) 1991, 1992 Linus Torvalds
+ * This program 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
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
*
- * ext2 symlink handling code
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
- * Modified for OBDFS:
- * Copyright (C) 1999 Seagate Technology Inc. (author: braam@stelias.com)
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2014, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/stat.h>
-#include <linux/locks.h>
-
+#include <linux/version.h>
#define DEBUG_SUBSYSTEM S_LLITE
-#include <linux/obd_support.h> /* for ENTRY and EXIT only */
-#include <linux/lustre_lite.h>
+#include "llite_internal.h"
-static int ll_readlink(struct dentry *dentry, char *buffer, int buflen)
+static int ll_readlink_internal(struct inode *inode,
+ struct ptlrpc_request **request, char **symname)
{
- struct ll_sb_info *sbi = ll_i2sbi(dentry->d_inode);
- struct ptlrpc_request *request;
- char *tmp;
- int rc, size;
- ENTRY;
-
- rc = mdc_getattr(&sbi->ll_mds_client, sbi->ll_mds_conn,
- dentry->d_inode->i_ino, S_IFLNK,
- OBD_MD_LINKNAME, dentry->d_inode->i_size, &request);
- if (rc) {
- CERROR("failure %d inode %ld\n", rc,
- (long)dentry->d_inode->i_ino);
- ptlrpc_free_req(request);
- RETURN(rc);
- }
-
- tmp = lustre_msg_buf(request->rq_repmsg, 1);
- size = MIN(request->rq_repmsg->buflens[1], buflen);
- rc = copy_to_user(buffer, tmp, size);
- if (rc == 0)
- rc = size;
-
- ptlrpc_free_req(request);
- RETURN(rc);
+ struct ll_inode_info *lli = ll_i2info(inode);
+ struct ll_sb_info *sbi = ll_i2sbi(inode);
+ int rc, symlen = i_size_read(inode) + 1;
+ struct mdt_body *body;
+ struct md_op_data *op_data;
+
+ ENTRY;
+
+ *request = NULL;
+
+ if (lli->lli_symlink_name) {
+ int print_limit = min_t(int, PAGE_SIZE - 128, symlen);
+
+ *symname = lli->lli_symlink_name;
+ /*
+ * If the total CDEBUG() size is larger than a page, it
+ * will print a warning to the console, avoid this by
+ * printing just the last part of the symlink.
+ */
+ CDEBUG(D_INODE, "using cached symlink %s%.*s, len = %d\n",
+ print_limit < symlen ? "..." : "", print_limit,
+ (*symname) + symlen - print_limit, symlen);
+ RETURN(0);
+ }
+
+ op_data = ll_prep_md_op_data(NULL, inode, NULL, NULL, 0, symlen,
+ LUSTRE_OPC_ANY, NULL);
+ if (IS_ERR(op_data))
+ RETURN(PTR_ERR(op_data));
+
+ op_data->op_valid = OBD_MD_LINKNAME;
+ rc = md_getattr(sbi->ll_md_exp, op_data, request);
+ ll_finish_md_op_data(op_data);
+ if (rc) {
+ if (rc != -ENOENT)
+ CERROR("%s: inode "DFID": rc = %d\n",
+ ll_i2sbi(inode)->ll_fsname,
+ PFID(ll_inode2fid(inode)), rc);
+ GOTO(failed, rc);
+ }
+
+ body = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_BODY);
+ LASSERT(body != NULL);
+ if ((body->mbo_valid & OBD_MD_LINKNAME) == 0) {
+ CERROR("OBD_MD_LINKNAME not set on reply\n");
+ GOTO(failed, rc = -EPROTO);
+ }
+
+ LASSERT(symlen != 0);
+ if (body->mbo_eadatasize != symlen) {
+ CERROR("%s: inode "DFID": symlink length %d not expected %d\n",
+ sbi->ll_fsname, PFID(ll_inode2fid(inode)),
+ body->mbo_eadatasize - 1, symlen - 1);
+ GOTO(failed, rc = -EPROTO);
+ }
+
+ *symname = req_capsule_server_get(&(*request)->rq_pill, &RMF_MDT_MD);
+ if (!*symname || strnlen(*symname, symlen) != symlen - 1) {
+ /* not full/NULL terminated */
+ CERROR("%s: inode "DFID": symlink not NULL terminated string of length %d\n",
+ sbi->ll_fsname,
+ PFID(ll_inode2fid(inode)), symlen - 1);
+ GOTO(failed, rc = -EPROTO);
+ }
+
+ OBD_ALLOC(lli->lli_symlink_name, symlen);
+ /* do not return an error if we cannot cache the symlink locally */
+ if (lli->lli_symlink_name) {
+ memcpy(lli->lli_symlink_name, *symname, symlen);
+ *symname = lli->lli_symlink_name;
+ }
+ RETURN(0);
+
+failed:
+ RETURN(rc);
+}
+
+#ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
+static void ll_put_link(struct dentry *dentry,
+ struct nameidata *nd, void *cookie)
+#else
+# ifdef HAVE_IOP_GET_LINK
+static void ll_put_link(void *cookie)
+# else
+static void ll_put_link(struct inode *unused, void *cookie)
+# endif
+#endif
+{
+ ptlrpc_req_finished(cookie);
+}
+
+#ifdef HAVE_SYMLINK_OPS_USE_NAMEIDATA
+static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct inode *inode = dentry->d_inode;
+ struct ptlrpc_request *request = NULL;
+ int rc;
+ char *symname = NULL;
+
+ ENTRY;
+
+ CDEBUG(D_VFSTRACE, "VFS Op\n");
+ /*
+ * Limit the recursive symlink depth to 5 instead of default
+ * 8 links when kernel has 4k stack to prevent stack overflow.
+ * For 8k stacks we need to limit it to 7 for local servers.
+ */
+ if (THREAD_SIZE < 8192 && current->link_count >= 6) {
+ rc = -ELOOP;
+ } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
+ rc = -ELOOP;
+ } else {
+ ll_inode_size_lock(inode);
+ rc = ll_readlink_internal(inode, &request, &symname);
+ ll_inode_size_unlock(inode);
+ }
+ if (rc) {
+ ptlrpc_req_finished(request);
+ request = NULL;
+ symname = ERR_PTR(rc);
+ }
+
+ nd_set_link(nd, symname);
+ /*
+ * symname may contain a pointer to the request message buffer,
+ * we delay request releasing until ll_put_link then.
+ */
+ RETURN(request);
+}
+#else
+# ifdef HAVE_IOP_GET_LINK
+static const char *ll_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
+{
+ struct ptlrpc_request *request;
+ char *symname = NULL;
+ int rc;
+
+ ENTRY;
+ CDEBUG(D_VFSTRACE, "VFS Op\n");
+ if (!dentry)
+ RETURN(ERR_PTR(-ECHILD));
+ ll_inode_size_lock(inode);
+ rc = ll_readlink_internal(inode, &request, &symname);
+ ll_inode_size_unlock(inode);
+ if (rc < 0) {
+ ptlrpc_req_finished(request);
+ return ERR_PTR(rc);
+ }
+
+ /*
+ * symname may contain a pointer to the request message buffer,
+ * we delay request releasing then.
+ */
+ set_delayed_call(done, ll_put_link, request);
+ RETURN(symname);
+}
+# else
+static const char *ll_follow_link(struct dentry *dentry, void **cookie)
+{
+ struct inode *inode = d_inode(dentry);
+ struct ptlrpc_request *request;
+ char *symname = NULL;
+ int rc;
+
+ ENTRY;
+
+ CDEBUG(D_VFSTRACE, "VFS Op\n");
+ ll_inode_size_lock(inode);
+ rc = ll_readlink_internal(inode, &request, &symname);
+ ll_inode_size_unlock(inode);
+ if (rc < 0) {
+ ptlrpc_req_finished(request);
+ return ERR_PTR(rc);
+ }
+
+ /*
+ * symname may contain a pointer to the request message buffer,
+ * we delay request releasing until ll_put_link then.
+ */
+ *cookie = request;
+ RETURN(symname);
}
+# endif /* HAVE_IOP_GET_LINK */
+#endif /* HAVE_SYMLINK_OPS_USE_NAMEIDATA */
-extern int ll_setattr(struct dentry *de, struct iattr *attr);
struct inode_operations ll_fast_symlink_inode_operations = {
- readlink: ll_readlink,
- setattr: ll_setattr
+#ifdef HAVE_IOP_GENERIC_READLINK
+ .readlink = generic_readlink,
+#endif
+ .setattr = ll_setattr,
+#ifdef HAVE_IOP_GET_LINK
+ .get_link = ll_get_link,
+#else
+ .follow_link = ll_follow_link,
+ .put_link = ll_put_link,
+#endif
+ .getattr = ll_getattr,
+ .permission = ll_inode_permission,
+#ifdef HAVE_IOP_XATTR
+ .setxattr = ll_setxattr,
+ .getxattr = ll_getxattr,
+ .removexattr = ll_removexattr,
+#endif
+ .listxattr = ll_listxattr,
};
git://git.whamcloud.com / fs / lustre-release.git / blobdiff