fs/cifs/link.c - maze/linux - Git at Google

 /*
  *   fs/cifs/link.c
  *
  *   Copyright (C) International Business Machines  Corp., 2002,2003
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *
  *   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
  */
 #include <linux/fs.h>
 #include <linux/stat.h>
 #include <linux/namei.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"

 int
 cifs_hardlink(struct dentry *old_file, struct inode *inode,
 	      struct dentry *direntry)
 {
 	int rc = -EACCES;
 	int xid;
 	char *fromName = NULL;
 	char *toName = NULL;
 	struct cifs_sb_info *cifs_sb_target;
 	struct cifsTconInfo *pTcon;
 	struct cifsInodeInfo *cifsInode;

 	xid = GetXid();

 	cifs_sb_target = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb_target->tcon;

 /* No need to check for cross device links since server will do that
    BB note DFS case in future though (when we may have to check) */

 	down(&inode->i_sb->s_vfs_rename_sem);
 	fromName = build_path_from_dentry(old_file);
 	toName = build_path_from_dentry(direntry);
 	up(&inode->i_sb->s_vfs_rename_sem);
 	if((fromName == NULL) || (toName == NULL)) {
 		rc = -ENOMEM;
 		goto cifs_hl_exit;
 	}

 	if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
 		rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
 					    cifs_sb_target->local_nls,
 					    cifs_sb_target->mnt_cifs_flags &
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 	else {
 		rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
 					cifs_sb_target->local_nls,
 					cifs_sb_target->mnt_cifs_flags &
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 		if(rc == -EIO)
 			rc = -EOPNOTSUPP;
 	}

 /* if (!rc)     */
 	{
 		/*   renew_parental_timestamps(old_file);
 		   inode->i_nlink++;
 		   mark_inode_dirty(inode);
 		   d_instantiate(direntry, inode); */
 		/* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
 	}
 	d_drop(direntry);	/* force new lookup from server */
 	cifsInode = CIFS_I(old_file->d_inode);
 	cifsInode->time = 0;	/* will force revalidate to go get info when needed */

 cifs_hl_exit:
 	if (fromName)
 		kfree(fromName);
 	if (toName)
 		kfree(toName);
 	FreeXid(xid);
 	return rc;
 }

 void *
 cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
 {
 	struct inode *inode = direntry->d_inode;
 	int rc = -EACCES;
 	int xid;
 	char *full_path = NULL;
 	char * target_path = ERR_PTR(-ENOMEM);
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;

 	xid = GetXid();

 	down(&direntry->d_sb->s_vfs_rename_sem);
 	full_path = build_path_from_dentry(direntry);
 	up(&direntry->d_sb->s_vfs_rename_sem);

 	if (!full_path)
 		goto out_no_free;

 	cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
 	cifs_sb = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb->tcon;
 	target_path = kmalloc(PATH_MAX, GFP_KERNEL);
 	if (!target_path) {
 		target_path = ERR_PTR(-ENOMEM);
 		goto out;
 	}

 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 	if (pTcon->ses->capabilities & CAP_UNIX)
 		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 					     target_path,
 					     PATH_MAX-1,
 					     cifs_sb->local_nls);
 	else {
 		/* rc = CIFSSMBQueryReparseLinkInfo */
 		/* BB Add code to Query ReparsePoint info */
 		/* BB Add MAC style xsymlink check here if enabled */
 	}

 	if (rc == 0) {

 /* BB Add special case check for Samba DFS symlinks */

 		target_path[PATH_MAX-1] = 0;
 	} else {
 		kfree(target_path);
 		target_path = ERR_PTR(rc);
 	}

 out:
 	kfree(full_path);
 out_no_free:
 	FreeXid(xid);
 	nd_set_link(nd, target_path);
 	return NULL;	/* No cookie */
 }

 int
 cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 {
 	int rc = -EOPNOTSUPP;
 	int xid;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	char *full_path = NULL;
 	struct inode *newinode = NULL;

 	xid = GetXid();

 	cifs_sb = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb->tcon;

 	down(&inode->i_sb->s_vfs_rename_sem);
 	full_path = build_path_from_dentry(direntry);
 	up(&inode->i_sb->s_vfs_rename_sem);

 	if(full_path == NULL) {
 		FreeXid(xid);
 		return -ENOMEM;
 	}

 	cFYI(1, ("Full path: %s ", full_path));
 	cFYI(1, ("symname is %s", symname));

 	/* BB what if DFS and this volume is on different share? BB */
 	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 					   cifs_sb->local_nls);
 	/* else
 	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */

 	if (rc == 0) {
 		if (pTcon->ses->capabilities & CAP_UNIX)
 			rc = cifs_get_inode_info_unix(&newinode, full_path,
 						      inode->i_sb,xid);
 		else
 			rc = cifs_get_inode_info(&newinode, full_path, NULL,
 						 inode->i_sb,xid);

 		if (rc != 0) {
 			cFYI(1,
 			     ("Create symlink worked but get_inode_info failed with rc = %d ",
 			      rc));
 		} else {
 			if (pTcon->nocase)
 				direntry->d_op = &cifs_ci_dentry_ops;
 			else
 				direntry->d_op = &cifs_dentry_ops;
 			d_instantiate(direntry, newinode);
 		}
 	}

 	if (full_path)
 		kfree(full_path);
 	FreeXid(xid);
 	return rc;
 }

 int
 cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
 {
 	struct inode *inode = direntry->d_inode;
 	int rc = -EACCES;
 	int xid;
 	int oplock = FALSE;
 	struct cifs_sb_info *cifs_sb;
 	struct cifsTconInfo *pTcon;
 	char *full_path = NULL;
 	char *tmp_path =  NULL;
 	char * tmpbuffer;
 	unsigned char * referrals = NULL;
 	int num_referrals = 0;
 	int len;
 	__u16 fid;

 	xid = GetXid();
 	cifs_sb = CIFS_SB(inode->i_sb);
 	pTcon = cifs_sb->tcon;

 /* BB would it be safe against deadlock to grab this sem
       even though rename itself grabs the sem and calls lookup? */
 /*       down(&inode->i_sb->s_vfs_rename_sem);*/
 	full_path = build_path_from_dentry(direntry);
 /*       up(&inode->i_sb->s_vfs_rename_sem);*/

 	if(full_path == NULL) {
 		FreeXid(xid);
 		return -ENOMEM;
 	}

 	cFYI(1,
 	     ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
 	      full_path, inode, pBuffer, buflen));
 	if(buflen > PATH_MAX)
 		len = PATH_MAX;
 	else
 		len = buflen;
 	tmpbuffer = kmalloc(len,GFP_KERNEL);
 	if(tmpbuffer == NULL) {
 		if (full_path)
 			kfree(full_path);
 		FreeXid(xid);
 		return -ENOMEM;
 	}

 /* BB add read reparse point symlink code and Unix extensions symlink code here BB */
 	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
 		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
 				tmpbuffer,
 				len - 1,
 				cifs_sb->local_nls);
 	else {
 		rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
 				OPEN_REPARSE_POINT,&fid, &oplock, NULL,
 				cifs_sb->local_nls,
 				cifs_sb->mnt_cifs_flags &
 					CIFS_MOUNT_MAP_SPECIAL_CHR);
 		if(!rc) {
 			rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
 				tmpbuffer,
 				len - 1,
 				fid,
 				cifs_sb->local_nls);
 			if(CIFSSMBClose(xid, pTcon, fid)) {
 				cFYI(1,("Error closing junction point (open for ioctl)"));
 			}
 			if(rc == -EIO) {
 				/* Query if DFS Junction */
 				tmp_path =
 					kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
 						GFP_KERNEL);
 				if (tmp_path) {
 					strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
 					strncat(tmp_path, full_path, MAX_PATHCONF);
 					rc = get_dfs_path(xid, pTcon->ses, tmp_path,
 						cifs_sb->local_nls,
 						&num_referrals, &referrals,
 						cifs_sb->mnt_cifs_flags &
 						    CIFS_MOUNT_MAP_SPECIAL_CHR);
 					cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
 					if((num_referrals == 0) && (rc == 0))
 						rc = -EACCES;
 					else {
 						cFYI(1,("num referral: %d",num_referrals));
 						if(referrals) {
 							cFYI(1,("referral string: %s ",referrals));
 							strncpy(tmpbuffer, referrals, len-1);
 						}
 					}
 					if(referrals)
 						kfree(referrals);
 					kfree(tmp_path);
 }
 				/* BB add code like else decode referrals then memcpy to
 				  tmpbuffer and free referrals string array BB */
 			}
 		}
 	}
 	/* BB Anything else to do to handle recursive links? */
 	/* BB Should we be using page ops here? */

 	/* BB null terminate returned string in pBuffer? BB */
 	if (rc == 0) {
 		rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
 		cFYI(1,
 		     ("vfs_readlink called from cifs_readlink returned %d",
 		      rc));
 	}

 	if (tmpbuffer) {
 		kfree(tmpbuffer);
 	}
 	if (full_path) {
 		kfree(full_path);
 	}
 	FreeXid(xid);
 	return rc;
 }

 void cifs_put_link(struct dentry *direntry, struct nameidata *nd, void *cookie)
 {
 	char *p = nd_get_link(nd);
 	if (!IS_ERR(p))
 		kfree(p);
 }
	/*
	* fs/cifs/link.c
	*
	* Copyright (C) International Business Machines Corp., 2002,2003
	* Author(s): Steve French (sfrench@us.ibm.com)
	*
	* 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
	*/
	#include <linux/fs.h>
	#include <linux/stat.h>
	#include <linux/namei.h>
	#include "cifsfs.h"
	#include "cifspdu.h"
	#include "cifsglob.h"
	#include "cifsproto.h"
	#include "cifs_debug.h"
	#include "cifs_fs_sb.h"

	int
	cifs_hardlink(struct dentry old_file, struct inode inode,
	struct dentry *direntry)
	{
	int rc = -EACCES;
	int xid;
	char *fromName = NULL;
	char *toName = NULL;
	struct cifs_sb_info *cifs_sb_target;
	struct cifsTconInfo *pTcon;
	struct cifsInodeInfo *cifsInode;

	xid = GetXid();

	cifs_sb_target = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb_target->tcon;

	/* No need to check for cross device links since server will do that
	BB note DFS case in future though (when we may have to check) */

	down(&inode->i_sb->s_vfs_rename_sem);
	fromName = build_path_from_dentry(old_file);
	toName = build_path_from_dentry(direntry);
	up(&inode->i_sb->s_vfs_rename_sem);
	if((fromName == NULL) \|\| (toName == NULL)) {
	rc = -ENOMEM;
	goto cifs_hl_exit;
	}

	if (cifs_sb_target->tcon->ses->capabilities & CAP_UNIX)
	rc = CIFSUnixCreateHardLink(xid, pTcon, fromName, toName,
	cifs_sb_target->local_nls,
	cifs_sb_target->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	else {
	rc = CIFSCreateHardLink(xid, pTcon, fromName, toName,
	cifs_sb_target->local_nls,
	cifs_sb_target->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	if(rc == -EIO)
	rc = -EOPNOTSUPP;
	}

	/* if (!rc) */
	{
	/* renew_parental_timestamps(old_file);
	inode->i_nlink++;
	mark_inode_dirty(inode);
	d_instantiate(direntry, inode); */
	/* BB add call to either mark inode dirty or refresh its data and timestamp to current time */
	}
	d_drop(direntry); /* force new lookup from server */
	cifsInode = CIFS_I(old_file->d_inode);
	cifsInode->time = 0; /* will force revalidate to go get info when needed */

	cifs_hl_exit:
	if (fromName)
	kfree(fromName);
	if (toName)
	kfree(toName);
	FreeXid(xid);
	return rc;
	}

	void *
	cifs_follow_link(struct dentry direntry, struct nameidata nd)
	{
	struct inode *inode = direntry->d_inode;
	int rc = -EACCES;
	int xid;
	char *full_path = NULL;
	char * target_path = ERR_PTR(-ENOMEM);
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	down(&direntry->d_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&direntry->d_sb->s_vfs_rename_sem);

	if (!full_path)
	goto out_no_free;

	cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
	target_path = kmalloc(PATH_MAX, GFP_KERNEL);
	if (!target_path) {
	target_path = ERR_PTR(-ENOMEM);
	goto out;
	}

	/* BB add read reparse point symlink code and Unix extensions symlink code here BB */
	if (pTcon->ses->capabilities & CAP_UNIX)
	rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
	target_path,
	PATH_MAX-1,
	cifs_sb->local_nls);
	else {
	/* rc = CIFSSMBQueryReparseLinkInfo */
	/* BB Add code to Query ReparsePoint info */
	/* BB Add MAC style xsymlink check here if enabled */
	}

	if (rc == 0) {

	/* BB Add special case check for Samba DFS symlinks */

	target_path[PATH_MAX-1] = 0;
	} else {
	kfree(target_path);
	target_path = ERR_PTR(rc);
	}

	out:
	kfree(full_path);
	out_no_free:
	FreeXid(xid);
	nd_set_link(nd, target_path);
	return NULL; /* No cookie */
	}

	int
	cifs_symlink(struct inode inode, struct dentry direntry, const char *symname)
	{
	int rc = -EOPNOTSUPP;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode *newinode = NULL;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	down(&inode->i_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&inode->i_sb->s_vfs_rename_sem);

	if(full_path == NULL) {
	FreeXid(xid);
	return -ENOMEM;
	}

	cFYI(1, ("Full path: %s ", full_path));
	cFYI(1, ("symname is %s", symname));

	/* BB what if DFS and this volume is on different share? BB */
	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
	rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
	cifs_sb->local_nls);
	/* else
	rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,cifs_sb_target->local_nls); */

	if (rc == 0) {
	if (pTcon->ses->capabilities & CAP_UNIX)
	rc = cifs_get_inode_info_unix(&newinode, full_path,
	inode->i_sb,xid);
	else
	rc = cifs_get_inode_info(&newinode, full_path, NULL,
	inode->i_sb,xid);

	if (rc != 0) {
	cFYI(1,
	("Create symlink worked but get_inode_info failed with rc = %d ",
	rc));
	} else {
	if (pTcon->nocase)
	direntry->d_op = &cifs_ci_dentry_ops;
	else
	direntry->d_op = &cifs_dentry_ops;
	d_instantiate(direntry, newinode);
	}
	}

	if (full_path)
	kfree(full_path);
	FreeXid(xid);
	return rc;
	}

	int
	cifs_readlink(struct dentry direntry, char __user pBuffer, int buflen)
	{
	struct inode *inode = direntry->d_inode;
	int rc = -EACCES;
	int xid;
	int oplock = FALSE;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	char *tmp_path = NULL;
	char * tmpbuffer;
	unsigned char * referrals = NULL;
	int num_referrals = 0;
	int len;
	__u16 fid;

	xid = GetXid();
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	/* BB would it be safe against deadlock to grab this sem
	even though rename itself grabs the sem and calls lookup? */
	/* down(&inode->i_sb->s_vfs_rename_sem);*/
	full_path = build_path_from_dentry(direntry);
	/* up(&inode->i_sb->s_vfs_rename_sem);*/

	if(full_path == NULL) {
	FreeXid(xid);
	return -ENOMEM;
	}

	cFYI(1,
	("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
	full_path, inode, pBuffer, buflen));
	if(buflen > PATH_MAX)
	len = PATH_MAX;
	else
	len = buflen;
	tmpbuffer = kmalloc(len,GFP_KERNEL);
	if(tmpbuffer == NULL) {
	if (full_path)
	kfree(full_path);
	FreeXid(xid);
	return -ENOMEM;
	}

	/* BB add read reparse point symlink code and Unix extensions symlink code here BB */
	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
	rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
	tmpbuffer,
	len - 1,
	cifs_sb->local_nls);
	else {
	rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
	OPEN_REPARSE_POINT,&fid, &oplock, NULL,
	cifs_sb->local_nls,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	if(!rc) {
	rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
	tmpbuffer,
	len - 1,
	fid,
	cifs_sb->local_nls);
	if(CIFSSMBClose(xid, pTcon, fid)) {
	cFYI(1,("Error closing junction point (open for ioctl)"));
	}
	if(rc == -EIO) {
	/* Query if DFS Junction */
	tmp_path =
	kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
	GFP_KERNEL);
	if (tmp_path) {
	strncpy(tmp_path, pTcon->treeName, MAX_TREE_SIZE);
	strncat(tmp_path, full_path, MAX_PATHCONF);
	rc = get_dfs_path(xid, pTcon->ses, tmp_path,
	cifs_sb->local_nls,
	&num_referrals, &referrals,
	cifs_sb->mnt_cifs_flags &
	CIFS_MOUNT_MAP_SPECIAL_CHR);
	cFYI(1,("Get DFS for %s rc = %d ",tmp_path, rc));
	if((num_referrals == 0) && (rc == 0))
	rc = -EACCES;
	else {
	cFYI(1,("num referral: %d",num_referrals));
	if(referrals) {
	cFYI(1,("referral string: %s ",referrals));
	strncpy(tmpbuffer, referrals, len-1);
	}
	}
	if(referrals)
	kfree(referrals);
	kfree(tmp_path);
	}
	/* BB add code like else decode referrals then memcpy to
	tmpbuffer and free referrals string array BB */
	}
	}
	}
	/* BB Anything else to do to handle recursive links? */
	/* BB Should we be using page ops here? */

	/* BB null terminate returned string in pBuffer? BB */
	if (rc == 0) {
	rc = vfs_readlink(direntry, pBuffer, len, tmpbuffer);
	cFYI(1,
	("vfs_readlink called from cifs_readlink returned %d",
	rc));
	}

	if (tmpbuffer) {
	kfree(tmpbuffer);
	}
	if (full_path) {
	kfree(full_path);
	}
	FreeXid(xid);
	return rc;
	}

	void cifs_put_link(struct dentry direntry, struct nameidata nd, void *cookie)
	{
	char *p = nd_get_link(nd);
	if (!IS_ERR(p))
	kfree(p);
	}