file.c 51.3 KB
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/*
 *   fs/cifs/file.c
 *
 *   vfs operations that deal with files
 * 
 *   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>
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#include <linux/backing-dev.h>
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#include <linux/stat.h>
#include <linux/fcntl.h>
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#include <linux/mpage.h>
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#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/smp_lock.h>
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#include <linux/writeback.h>
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#include <linux/delay.h>
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#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"

static inline struct cifsFileInfo *cifs_init_private(
	struct cifsFileInfo *private_data, struct inode *inode,
	struct file *file, __u16 netfid)
{
	memset(private_data, 0, sizeof(struct cifsFileInfo));
	private_data->netfid = netfid;
	private_data->pid = current->tgid;	
	init_MUTEX(&private_data->fh_sem);
	private_data->pfile = file; /* needed for writepage */
	private_data->pInode = inode;
	private_data->invalidHandle = FALSE;
	private_data->closePend = FALSE;
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	/* we have to track num writers to the inode, since writepages
	does not tell us which handle the write is for so there can
	be a close (overlapping with write) of the filehandle that
	cifs_writepages chose to use */
	atomic_set(&private_data->wrtPending,0); 
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	return private_data;
}

static inline int cifs_convert_flags(unsigned int flags)
{
	if ((flags & O_ACCMODE) == O_RDONLY)
		return GENERIC_READ;
	else if ((flags & O_ACCMODE) == O_WRONLY)
		return GENERIC_WRITE;
	else if ((flags & O_ACCMODE) == O_RDWR) {
		/* GENERIC_ALL is too much permission to request
		   can cause unnecessary access denied on create */
		/* return GENERIC_ALL; */
		return (GENERIC_READ | GENERIC_WRITE);
	}

	return 0x20197;
}

static inline int cifs_get_disposition(unsigned int flags)
{
	if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
		return FILE_CREATE;
	else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
		return FILE_OVERWRITE_IF;
	else if ((flags & O_CREAT) == O_CREAT)
		return FILE_OPEN_IF;
	else
		return FILE_OPEN;
}

/* all arguments to this function must be checked for validity in caller */
static inline int cifs_open_inode_helper(struct inode *inode, struct file *file,
	struct cifsInodeInfo *pCifsInode, struct cifsFileInfo *pCifsFile,
	struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
	char *full_path, int xid)
{
	struct timespec temp;
	int rc;

	/* want handles we can use to read with first
	   in the list so we do not have to walk the
	   list to search for one in prepare_write */
	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
		list_add_tail(&pCifsFile->flist, 
			      &pCifsInode->openFileList);
	} else {
		list_add(&pCifsFile->flist,
			 &pCifsInode->openFileList);
	}
	write_unlock(&GlobalSMBSeslock);
	write_unlock(&file->f_owner.lock);
	if (pCifsInode->clientCanCacheRead) {
		/* we have the inode open somewhere else
		   no need to discard cache data */
		goto client_can_cache;
	}

	/* BB need same check in cifs_create too? */
	/* if not oplocked, invalidate inode pages if mtime or file
	   size changed */
	temp = cifs_NTtimeToUnix(le64_to_cpu(buf->LastWriteTime));
	if (timespec_equal(&file->f_dentry->d_inode->i_mtime, &temp) && 
			   (file->f_dentry->d_inode->i_size == 
			    (loff_t)le64_to_cpu(buf->EndOfFile))) {
		cFYI(1, ("inode unchanged on server"));
	} else {
		if (file->f_dentry->d_inode->i_mapping) {
		/* BB no need to lock inode until after invalidate
		   since namei code should already have it locked? */
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			filemap_write_and_wait(file->f_dentry->d_inode->i_mapping);
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		}
		cFYI(1, ("invalidating remote inode since open detected it "
			 "changed"));
		invalidate_remote_inode(file->f_dentry->d_inode);
	}

client_can_cache:
	if (pTcon->ses->capabilities & CAP_UNIX)
		rc = cifs_get_inode_info_unix(&file->f_dentry->d_inode,
			full_path, inode->i_sb, xid);
	else
		rc = cifs_get_inode_info(&file->f_dentry->d_inode,
			full_path, buf, inode->i_sb, xid);

	if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
		pCifsInode->clientCanCacheAll = TRUE;
		pCifsInode->clientCanCacheRead = TRUE;
		cFYI(1, ("Exclusive Oplock granted on inode %p",
			 file->f_dentry->d_inode));
	} else if ((*oplock & 0xF) == OPLOCK_READ)
		pCifsInode->clientCanCacheRead = TRUE;

	return rc;
}

int cifs_open(struct inode *inode, struct file *file)
{
	int rc = -EACCES;
	int xid, oplock;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;
	struct list_head *tmp;
	char *full_path = NULL;
	int desiredAccess;
	int disposition;
	__u16 netfid;
	FILE_ALL_INFO *buf = NULL;

	xid = GetXid();

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

	if (file->f_flags & O_CREAT) {
		/* search inode for this file and fill in file->private_data */
		pCifsInode = CIFS_I(file->f_dentry->d_inode);
		read_lock(&GlobalSMBSeslock);
		list_for_each(tmp, &pCifsInode->openFileList) {
			pCifsFile = list_entry(tmp, struct cifsFileInfo,
					       flist);
			if ((pCifsFile->pfile == NULL) &&
			    (pCifsFile->pid == current->tgid)) {
				/* mode set in cifs_create */

				/* needed for writepage */
				pCifsFile->pfile = file;
				
				file->private_data = pCifsFile;
				break;
			}
		}
		read_unlock(&GlobalSMBSeslock);
		if (file->private_data != NULL) {
			rc = 0;
			FreeXid(xid);
			return rc;
		} else {
			if (file->f_flags & O_EXCL)
				cERROR(1, ("could not find file instance for "
					   "new file %p ", file));
		}
	}

	down(&inode->i_sb->s_vfs_rename_sem);
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	full_path = build_path_from_dentry(file->f_dentry);
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	up(&inode->i_sb->s_vfs_rename_sem);
	if (full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

	cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
		 inode, file->f_flags, full_path));
	desiredAccess = cifs_convert_flags(file->f_flags);

/*********************************************************************
 *  open flag mapping table:
 *  
 *	POSIX Flag            CIFS Disposition
 *	----------            ---------------- 
 *	O_CREAT               FILE_OPEN_IF
 *	O_CREAT | O_EXCL      FILE_CREATE
 *	O_CREAT | O_TRUNC     FILE_OVERWRITE_IF
 *	O_TRUNC               FILE_OVERWRITE
 *	none of the above     FILE_OPEN
 *
 *	Note that there is not a direct match between disposition
 *	FILE_SUPERSEDE (ie create whether or not file exists although 
 *	O_CREAT | O_TRUNC is similar but truncates the existing
 *	file rather than creating a new file as FILE_SUPERSEDE does
 *	(which uses the attributes / metadata passed in on open call)
 *?
 *?  O_SYNC is a reasonable match to CIFS writethrough flag  
 *?  and the read write flags match reasonably.  O_LARGEFILE
 *?  is irrelevant because largefile support is always used
 *?  by this client. Flags O_APPEND, O_DIRECT, O_DIRECTORY,
 *	 O_FASYNC, O_NOFOLLOW, O_NONBLOCK need further investigation
 *********************************************************************/

	disposition = cifs_get_disposition(file->f_flags);

	if (oplockEnabled)
		oplock = REQ_OPLOCK;
	else
		oplock = FALSE;

	/* BB pass O_SYNC flag through on file attributes .. BB */

	/* Also refresh inode by passing in file_info buf returned by SMBOpen
	   and calling get_inode_info with returned buf (at least helps
	   non-Unix server case) */

	/* BB we can not do this if this is the second open of a file 
	   and the first handle has writebehind data, we might be 
	   able to simply do a filemap_fdatawrite/filemap_fdatawait first */
	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (!buf) {
		rc = -ENOMEM;
		goto out;
	}
	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
			 CREATE_NOT_DIR, &netfid, &oplock, buf,
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			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
				 & CIFS_MOUNT_MAP_SPECIAL_CHR);
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	if (rc == -EIO) {
		/* Old server, try legacy style OpenX */
		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
			desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf,
			cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
				& CIFS_MOUNT_MAP_SPECIAL_CHR);
	}
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	if (rc) {
		cFYI(1, ("cifs_open returned 0x%x ", rc));
		goto out;
	}
	file->private_data =
		kmalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
	if (file->private_data == NULL) {
		rc = -ENOMEM;
		goto out;
	}
	pCifsFile = cifs_init_private(file->private_data, inode, file, netfid);
	write_lock(&file->f_owner.lock);
	write_lock(&GlobalSMBSeslock);
	list_add(&pCifsFile->tlist, &pTcon->openFileList);

	pCifsInode = CIFS_I(file->f_dentry->d_inode);
	if (pCifsInode) {
		rc = cifs_open_inode_helper(inode, file, pCifsInode,
					    pCifsFile, pTcon,
					    &oplock, buf, full_path, xid);
	} else {
		write_unlock(&GlobalSMBSeslock);
		write_unlock(&file->f_owner.lock);
	}

	if (oplock & CIFS_CREATE_ACTION) {           
		/* time to set mode which we can not set earlier due to
		   problems creating new read-only files */
		if (cifs_sb->tcon->ses->capabilities & CAP_UNIX) {
			CIFSSMBUnixSetPerms(xid, pTcon, full_path,
					    inode->i_mode,
					    (__u64)-1, (__u64)-1, 0 /* dev */,
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					    cifs_sb->local_nls,
					    cifs_sb->mnt_cifs_flags & 
						CIFS_MOUNT_MAP_SPECIAL_CHR);
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		} else {
			/* BB implement via Windows security descriptors eg
			   CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
					      -1, -1, local_nls);
			   in the meantime could set r/o dos attribute when
			   perms are eg: mode & 0222 == 0 */
		}
	}

out:
	kfree(buf);
	kfree(full_path);
	FreeXid(xid);
	return rc;
}

/* Try to reaquire byte range locks that were released when session */
/* to server was lost */
static int cifs_relock_file(struct cifsFileInfo *cifsFile)
{
	int rc = 0;

/* BB list all locks open on this file and relock */

	return rc;
}

static int cifs_reopen_file(struct inode *inode, struct file *file, 
	int can_flush)
{
	int rc = -EACCES;
	int xid, oplock;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pCifsFile;
	struct cifsInodeInfo *pCifsInode;
	char *full_path = NULL;
	int desiredAccess;
	int disposition = FILE_OPEN;
	__u16 netfid;

	if (inode == NULL)
		return -EBADF;
	if (file->private_data) {
		pCifsFile = (struct cifsFileInfo *)file->private_data;
	} else
		return -EBADF;

	xid = GetXid();
	down(&pCifsFile->fh_sem);
	if (pCifsFile->invalidHandle == FALSE) {
		up(&pCifsFile->fh_sem);
		FreeXid(xid);
		return 0;
	}

	if (file->f_dentry == NULL) {
		up(&pCifsFile->fh_sem);
		cFYI(1, ("failed file reopen, no valid name if dentry freed"));
		FreeXid(xid);
		return -EBADF;
	}
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
/* can not grab rename sem here because various ops, including
   those that already have the rename sem can end up causing writepage
   to get called and if the server was down that means we end up here,
   and we can never tell if the caller already has the rename_sem */
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	full_path = build_path_from_dentry(file->f_dentry);
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	if (full_path == NULL) {
		up(&pCifsFile->fh_sem);
		FreeXid(xid);
		return -ENOMEM;
	}

	cFYI(1, (" inode = 0x%p file flags are 0x%x for %s",
		 inode, file->f_flags,full_path));
	desiredAccess = cifs_convert_flags(file->f_flags);

	if (oplockEnabled)
		oplock = REQ_OPLOCK;
	else
		oplock = FALSE;

	/* Can not refresh inode by passing in file_info buf to be returned
	   by SMBOpen and then calling get_inode_info with returned buf 
	   since file might have write behind data that needs to be flushed 
	   and server version of file size can be stale. If we knew for sure
	   that inode was not dirty locally we could do this */

/*	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (buf == 0) {
		up(&pCifsFile->fh_sem);
		kfree(full_path);
		FreeXid(xid);
		return -ENOMEM;
	} */
	rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, desiredAccess,
			 CREATE_NOT_DIR, &netfid, &oplock, NULL,
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			 cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & 
				CIFS_MOUNT_MAP_SPECIAL_CHR);
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	if (rc) {
		up(&pCifsFile->fh_sem);
		cFYI(1, ("cifs_open returned 0x%x ", rc));
		cFYI(1, ("oplock: %d ", oplock));
	} else {
		pCifsFile->netfid = netfid;
		pCifsFile->invalidHandle = FALSE;
		up(&pCifsFile->fh_sem);
		pCifsInode = CIFS_I(inode);
		if (pCifsInode) {
			if (can_flush) {
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				filemap_write_and_wait(inode->i_mapping);
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			/* temporarily disable caching while we
			   go to server to get inode info */
				pCifsInode->clientCanCacheAll = FALSE;
				pCifsInode->clientCanCacheRead = FALSE;
				if (pTcon->ses->capabilities & CAP_UNIX)
					rc = cifs_get_inode_info_unix(&inode,
						full_path, inode->i_sb, xid);
				else
					rc = cifs_get_inode_info(&inode,
						full_path, NULL, inode->i_sb,
						xid);
			} /* else we are writing out data to server already
			     and could deadlock if we tried to flush data, and
			     since we do not know if we have data that would
			     invalidate the current end of file on the server
			     we can not go to the server to get the new inod
			     info */
			if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
				pCifsInode->clientCanCacheAll = TRUE;
				pCifsInode->clientCanCacheRead = TRUE;
				cFYI(1, ("Exclusive Oplock granted on inode %p",
					 file->f_dentry->d_inode));
			} else if ((oplock & 0xF) == OPLOCK_READ) {
				pCifsInode->clientCanCacheRead = TRUE;
				pCifsInode->clientCanCacheAll = FALSE;
			} else {
				pCifsInode->clientCanCacheRead = FALSE;
				pCifsInode->clientCanCacheAll = FALSE;
			}
			cifs_relock_file(pCifsFile);
		}
	}

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

int cifs_close(struct inode *inode, struct file *file)
{
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct cifsFileInfo *pSMBFile =
		(struct cifsFileInfo *)file->private_data;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
	if (pSMBFile) {
		pSMBFile->closePend = TRUE;
		write_lock(&file->f_owner.lock);
		if (pTcon) {
			/* no sense reconnecting to close a file that is
			   already closed */
			if (pTcon->tidStatus != CifsNeedReconnect) {
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				int timeout = 2;
				while((atomic_read(&pSMBFile->wrtPending) != 0)
					 && (timeout < 1000) ) {
					/* Give write a better chance to get to
					server ahead of the close.  We do not
					want to add a wait_q here as it would
					increase the memory utilization as
					the struct would be in each open file,
					but this should give enough time to 
					clear the socket */
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					write_unlock(&file->f_owner.lock);
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					cERROR(1,("close with pending writes"));
					msleep(timeout);
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					write_lock(&file->f_owner.lock);
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					timeout *= 4;
				} 
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				write_unlock(&file->f_owner.lock);
				rc = CIFSSMBClose(xid, pTcon,
						  pSMBFile->netfid);
				write_lock(&file->f_owner.lock);
			}
		}
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		write_lock(&GlobalSMBSeslock);
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		list_del(&pSMBFile->flist);
		list_del(&pSMBFile->tlist);
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		write_unlock(&GlobalSMBSeslock);
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		write_unlock(&file->f_owner.lock);
		kfree(pSMBFile->search_resume_name);
		kfree(file->private_data);
		file->private_data = NULL;
	} else
		rc = -EBADF;

	if (list_empty(&(CIFS_I(inode)->openFileList))) {
		cFYI(1, ("closing last open instance for inode %p", inode));
		/* if the file is not open we do not know if we can cache info
		   on this inode, much less write behind and read ahead */
		CIFS_I(inode)->clientCanCacheRead = FALSE;
		CIFS_I(inode)->clientCanCacheAll  = FALSE;
	}
	if ((rc ==0) && CIFS_I(inode)->write_behind_rc)
		rc = CIFS_I(inode)->write_behind_rc;
	FreeXid(xid);
	return rc;
}

int cifs_closedir(struct inode *inode, struct file *file)
{
	int rc = 0;
	int xid;
	struct cifsFileInfo *pCFileStruct =
	    (struct cifsFileInfo *)file->private_data;
	char *ptmp;

	cFYI(1, ("Closedir inode = 0x%p with ", inode));

	xid = GetXid();

	if (pCFileStruct) {
		struct cifsTconInfo *pTcon;
		struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_dentry->d_sb);

		pTcon = cifs_sb->tcon;

		cFYI(1, ("Freeing private data in close dir"));
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		if ((pCFileStruct->srch_inf.endOfSearch == FALSE) &&
		   (pCFileStruct->invalidHandle == FALSE)) {
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			pCFileStruct->invalidHandle = TRUE;
			rc = CIFSFindClose(xid, pTcon, pCFileStruct->netfid);
			cFYI(1, ("Closing uncompleted readdir with rc %d",
				 rc));
			/* not much we can do if it fails anyway, ignore rc */
			rc = 0;
		}
		ptmp = pCFileStruct->srch_inf.ntwrk_buf_start;
		if (ptmp) {
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			cFYI(1, ("closedir free smb buf in srch struct"));
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			pCFileStruct->srch_inf.ntwrk_buf_start = NULL;
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			if(pCFileStruct->srch_inf.smallBuf)
				cifs_small_buf_release(ptmp);
			else
				cifs_buf_release(ptmp);
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		}
		ptmp = pCFileStruct->search_resume_name;
		if (ptmp) {
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			cFYI(1, ("closedir free resume name"));
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			pCFileStruct->search_resume_name = NULL;
			kfree(ptmp);
		}
		kfree(file->private_data);
		file->private_data = NULL;
	}
	/* BB can we lock the filestruct while this is going on? */
	FreeXid(xid);
	return rc;
}

int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock)
{
	int rc, xid;
	__u32 lockType = LOCKING_ANDX_LARGE_FILES;
	__u32 numLock = 0;
	__u32 numUnlock = 0;
	__u64 length;
	int wait_flag = FALSE;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	length = 1 + pfLock->fl_end - pfLock->fl_start;
	rc = -EACCES;
	xid = GetXid();

	cFYI(1, ("Lock parm: 0x%x flockflags: "
		 "0x%x flocktype: 0x%x start: %lld end: %lld",
	        cmd, pfLock->fl_flags, pfLock->fl_type, pfLock->fl_start,
	        pfLock->fl_end));

	if (pfLock->fl_flags & FL_POSIX)
598
		cFYI(1, ("Posix"));
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	if (pfLock->fl_flags & FL_FLOCK)
600
		cFYI(1, ("Flock"));
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	if (pfLock->fl_flags & FL_SLEEP) {
602
		cFYI(1, ("Blocking lock"));
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		wait_flag = TRUE;
	}
	if (pfLock->fl_flags & FL_ACCESS)
		cFYI(1, ("Process suspended by mandatory locking - "
			 "not implemented yet "));
	if (pfLock->fl_flags & FL_LEASE)
		cFYI(1, ("Lease on file - not implemented yet"));
	if (pfLock->fl_flags & 
	    (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE)))
		cFYI(1, ("Unknown lock flags 0x%x", pfLock->fl_flags));

	if (pfLock->fl_type == F_WRLCK) {
		cFYI(1, ("F_WRLCK "));
		numLock = 1;
	} else if (pfLock->fl_type == F_UNLCK) {
618
		cFYI(1, ("F_UNLCK"));
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		numUnlock = 1;
620 621
		/* Check if unlock includes more than
		one lock range */
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	} else if (pfLock->fl_type == F_RDLCK) {
623
		cFYI(1, ("F_RDLCK"));
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		lockType |= LOCKING_ANDX_SHARED_LOCK;
		numLock = 1;
	} else if (pfLock->fl_type == F_EXLCK) {
627
		cFYI(1, ("F_EXLCK"));
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		numLock = 1;
	} else if (pfLock->fl_type == F_SHLCK) {
630
		cFYI(1, ("F_SHLCK"));
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		lockType |= LOCKING_ANDX_SHARED_LOCK;
		numLock = 1;
	} else
634
		cFYI(1, ("Unknown type of lock"));
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	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}

	if (IS_GETLK(cmd)) {
		rc = CIFSSMBLock(xid, pTcon,
				 ((struct cifsFileInfo *)file->
				  private_data)->netfid,
				 length,
				 pfLock->fl_start, 0, 1, lockType,
				 0 /* wait flag */ );
		if (rc == 0) {
			rc = CIFSSMBLock(xid, pTcon,
					 ((struct cifsFileInfo *) file->
					  private_data)->netfid,
					 length,
					 pfLock->fl_start, 1 /* numUnlock */ ,
					 0 /* numLock */ , lockType,
					 0 /* wait flag */ );
			pfLock->fl_type = F_UNLCK;
			if (rc != 0)
				cERROR(1, ("Error unlocking previously locked "
					   "range %d during test of lock ",
					   rc));
			rc = 0;

		} else {
			/* if rc == ERR_SHARING_VIOLATION ? */
			rc = 0;	/* do not change lock type to unlock
				   since range in use */
		}

		FreeXid(xid);
		return rc;
	}

	rc = CIFSSMBLock(xid, pTcon,
			 ((struct cifsFileInfo *) file->private_data)->
			 netfid, length,
			 pfLock->fl_start, numUnlock, numLock, lockType,
			 wait_flag);
681
	if (pfLock->fl_flags & FL_POSIX)
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		posix_lock_file_wait(file, pfLock);
	FreeXid(xid);
	return rc;
}

ssize_t cifs_user_write(struct file *file, const char __user *write_data,
	size_t write_size, loff_t *poffset)
{
	int rc = 0;
	unsigned int bytes_written = 0;
	unsigned int total_written;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid, long_op;
	struct cifsFileInfo *open_file;

	if (file->f_dentry == NULL)
		return -EBADF;

	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	if (cifs_sb == NULL)
		return -EBADF;

	pTcon = cifs_sb->tcon;

	/* cFYI(1,
	   (" write %d bytes to offset %lld of %s", write_size,
	   *poffset, file->f_dentry->d_name.name)); */

	if (file->private_data == NULL)
		return -EBADF;
	else
		open_file = (struct cifsFileInfo *) file->private_data;
	
	xid = GetXid();
	if (file->f_dentry->d_inode == NULL) {
		FreeXid(xid);
		return -EBADF;
	}

	if (*poffset > file->f_dentry->d_inode->i_size)
		long_op = 2; /* writes past end of file can take a long time */
	else
		long_op = 1;

	for (total_written = 0; write_size > total_written;
	     total_written += bytes_written) {
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if (file->private_data == NULL) {
				/* file has been closed on us */
				FreeXid(xid);
			/* if we have gotten here we have written some data
			   and blocked, and the file has been freed on us while
			   we blocked so return what we managed to write */
				return total_written;
			} 
			if (open_file->closePend) {
				FreeXid(xid);
				if (total_written)
					return total_written;
				else
					return -EBADF;
			}
			if (open_file->invalidHandle) {
				if ((file->f_dentry == NULL) ||
				    (file->f_dentry->d_inode == NULL)) {
					FreeXid(xid);
					return total_written;
				}
				/* we could deadlock if we called
				   filemap_fdatawait from here so tell
				   reopen_file not to flush data to server
				   now */
				rc = cifs_reopen_file(file->f_dentry->d_inode,
					file, FALSE);
				if (rc != 0)
					break;
			}

			rc = CIFSSMBWrite(xid, pTcon,
				open_file->netfid,
				min_t(const int, cifs_sb->wsize,
				      write_size - total_written),
				*poffset, &bytes_written,
				NULL, write_data + total_written, long_op);
		}
		if (rc || (bytes_written == 0)) {
			if (total_written)
				break;
			else {
				FreeXid(xid);
				return rc;
			}
		} else
			*poffset += bytes_written;
		long_op = FALSE; /* subsequent writes fast -
				    15 seconds is plenty */
	}

782
	cifs_stats_bytes_written(pTcon, total_written);
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	/* since the write may have blocked check these pointers again */
	if (file->f_dentry) {
		if (file->f_dentry->d_inode) {
			struct inode *inode = file->f_dentry->d_inode;
			inode->i_ctime = inode->i_mtime =
				current_fs_time(inode->i_sb);
			if (total_written > 0) {
				if (*poffset > file->f_dentry->d_inode->i_size)
					i_size_write(file->f_dentry->d_inode,
					*poffset);
			}
			mark_inode_dirty_sync(file->f_dentry->d_inode);
		}
	}
	FreeXid(xid);
	return total_written;
}

static ssize_t cifs_write(struct file *file, const char *write_data,
	size_t write_size, loff_t *poffset)
{
	int rc = 0;
	unsigned int bytes_written = 0;
	unsigned int total_written;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid, long_op;
	struct cifsFileInfo *open_file;

	if (file->f_dentry == NULL)
		return -EBADF;

	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	if (cifs_sb == NULL)
		return -EBADF;

	pTcon = cifs_sb->tcon;

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	cFYI(1,("write %zd bytes to offset %lld of %s", write_size,
	   *poffset, file->f_dentry->d_name.name));
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	if (file->private_data == NULL)
		return -EBADF;
	else
		open_file = (struct cifsFileInfo *)file->private_data;
	
	xid = GetXid();
	if (file->f_dentry->d_inode == NULL) {
		FreeXid(xid);
		return -EBADF;
	}

	if (*poffset > file->f_dentry->d_inode->i_size)
		long_op = 2; /* writes past end of file can take a long time */
	else
		long_op = 1;

	for (total_written = 0; write_size > total_written;
	     total_written += bytes_written) {
		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if (file->private_data == NULL) {
				/* file has been closed on us */
				FreeXid(xid);
			/* if we have gotten here we have written some data
			   and blocked, and the file has been freed on us
			   while we blocked so return what we managed to 
			   write */
				return total_written;
			} 
			if (open_file->closePend) {
				FreeXid(xid);
				if (total_written)
					return total_written;
				else
					return -EBADF;
			}
			if (open_file->invalidHandle) {
				if ((file->f_dentry == NULL) ||
				   (file->f_dentry->d_inode == NULL)) {
					FreeXid(xid);
					return total_written;
				}
				/* we could deadlock if we called
				   filemap_fdatawait from here so tell
				   reopen_file not to flush data to 
				   server now */
				rc = cifs_reopen_file(file->f_dentry->d_inode,
					file, FALSE);
				if (rc != 0)
					break;
			}
876
			/* BB FIXME We can not sign across two buffers yet */
877 878
			if((pTcon->ses->server->secMode & 
			 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) == 0) {
879 880 881
				struct kvec iov[2];
				unsigned int len;

882
				len = min((size_t)cifs_sb->wsize,
883 884 885 886 887
					  write_size - total_written);
				/* iov[0] is reserved for smb header */
				iov[1].iov_base = (char *)write_data +
						  total_written;
				iov[1].iov_len = len;
888
				rc = CIFSSMBWrite2(xid, pTcon,
889
						open_file->netfid, len,
890
						*poffset, &bytes_written,
891
						iov, 1, long_op);
892 893
			} else
			/* BB FIXME fixup indentation of line below */
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			rc = CIFSSMBWrite(xid, pTcon,
				 open_file->netfid,
				 min_t(const int, cifs_sb->wsize, 
				       write_size - total_written),
				 *poffset, &bytes_written,
				 write_data + total_written, NULL, long_op);
		}
		if (rc || (bytes_written == 0)) {
			if (total_written)
				break;
			else {
				FreeXid(xid);
				return rc;
			}
		} else
			*poffset += bytes_written;
		long_op = FALSE; /* subsequent writes fast - 
				    15 seconds is plenty */
	}

914
	cifs_stats_bytes_written(pTcon, total_written);
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	/* since the write may have blocked check these pointers again */
	if (file->f_dentry) {
		if (file->f_dentry->d_inode) {
			file->f_dentry->d_inode->i_ctime = 
			file->f_dentry->d_inode->i_mtime = CURRENT_TIME;
			if (total_written > 0) {
				if (*poffset > file->f_dentry->d_inode->i_size)
					i_size_write(file->f_dentry->d_inode, 
						     *poffset);
			}
			mark_inode_dirty_sync(file->f_dentry->d_inode);
		}
	}
	FreeXid(xid);
	return total_written;
}

933
struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
934 935
{
	struct cifsFileInfo *open_file;
936
	int rc;
937 938 939 940 941 942 943 944

	read_lock(&GlobalSMBSeslock);
	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
		if (open_file->closePend)
			continue;
		if (open_file->pfile &&
		    ((open_file->pfile->f_flags & O_RDWR) ||
		     (open_file->pfile->f_flags & O_WRONLY))) {
945
			atomic_inc(&open_file->wrtPending);
946
			read_unlock(&GlobalSMBSeslock);
947
			if((open_file->invalidHandle) && 
948
			   (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) {
949
				rc = cifs_reopen_file(&cifs_inode->vfs_inode, 
950 951 952 953
						      open_file->pfile, FALSE);
				/* if it fails, try another handle - might be */
				/* dangerous to hold up writepages with retry */
				if(rc) {
954
					cFYI(1,("failed on reopen file in wp"));
955
					read_lock(&GlobalSMBSeslock);
956 957 958 959
					/* can not use this handle, no write
					pending on this one after all */
					atomic_dec
					     (&open_file->wrtPending);
960 961 962
					continue;
				}
			}
963 964 965 966 967 968 969
			return open_file;
		}
	}
	read_unlock(&GlobalSMBSeslock);
	return NULL;
}

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static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
{
	struct address_space *mapping = page->mapping;
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	char *write_data;
	int rc = -EFAULT;
	int bytes_written = 0;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct inode *inode;
980
	struct cifsFileInfo *open_file;
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	if (!mapping || !mapping->host)
		return -EFAULT;

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

	offset += (loff_t)from;
	write_data = kmap(page);
	write_data += from;

	if ((to > PAGE_CACHE_SIZE) || (from > to)) {
		kunmap(page);
		return -EIO;
	}

	/* racing with truncate? */
	if (offset > mapping->host->i_size) {
		kunmap(page);
		return 0; /* don't care */
	}

	/* check to make sure that we are not extending the file */
	if (mapping->host->i_size - offset < (loff_t)to)
		to = (unsigned)(mapping->host->i_size - offset); 

1008 1009 1010 1011
	open_file = find_writable_file(CIFS_I(mapping->host));
	if (open_file) {
		bytes_written = cifs_write(open_file->pfile, write_data,
					   to-from, &offset);
1012
		atomic_dec(&open_file->wrtPending);
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		/* Does mm or vfs already set times? */
1014 1015 1016 1017 1018 1019
		inode->i_atime = inode->i_mtime = current_fs_time(inode->i_sb);
		if ((bytes_written > 0) && (offset)) {
			rc = 0;
		} else if (bytes_written < 0) {
			if (rc != -EBADF)
				rc = bytes_written;
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		}
1021
	} else {
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		cFYI(1, ("No writeable filehandles for inode"));
		rc = -EIO;
	}

	kunmap(page);
	return rc;
}

static int cifs_writepages(struct address_space *mapping,
1031
			   struct writeback_control *wbc)
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{
1033 1034 1035 1036 1037 1038 1039 1040 1041
	struct backing_dev_info *bdi = mapping->backing_dev_info;
	unsigned int bytes_to_write;
	unsigned int bytes_written;
	struct cifs_sb_info *cifs_sb;
	int done = 0;
	pgoff_t end = -1;
	pgoff_t index;
	int is_range = 0;
	struct kvec iov[32];
1042
	int len;
1043 1044 1045 1046
	int n_iov = 0;
	pgoff_t next;
	int nr_pages;
	__u64 offset = 0;
1047
	struct cifsFileInfo *open_file;
1048 1049 1050 1051
	struct page *page;
	struct pagevec pvec;
	int rc = 0;
	int scanned = 0;
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	int xid;

1054 1055 1056 1057 1058 1059 1060 1061 1062
	cifs_sb = CIFS_SB(mapping->host->i_sb);
	
	/*
	 * If wsize is smaller that the page cache size, default to writing
	 * one page at a time via cifs_writepage
	 */
	if (cifs_sb->wsize < PAGE_CACHE_SIZE)
		return generic_writepages(mapping, wbc);

1063 1064 1065 1066 1067 1068 1069
	/* BB FIXME we do not have code to sign across multiple buffers yet,
	   so go to older writepage style write which we can sign if needed */
	if((cifs_sb->tcon->ses) && (cifs_sb->tcon->ses->server))
		if(cifs_sb->tcon->ses->server->secMode &
                          (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
			return generic_writepages(mapping, wbc);

1070 1071 1072 1073 1074 1075 1076 1077 1078
	/*
	 * BB: Is this meaningful for a non-block-device file system?
	 * If it is, we should test it again after we do I/O
	 */
	if (wbc->nonblocking && bdi_write_congested(bdi)) {
		wbc->encountered_congestion = 1;
		return 0;
	}

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	xid = GetXid();

1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146
	pagevec_init(&pvec, 0);
	if (wbc->sync_mode == WB_SYNC_NONE)
		index = mapping->writeback_index; /* Start from prev offset */
	else {
		index = 0;
		scanned = 1;
	}
	if (wbc->start || wbc->end) {
		index = wbc->start >> PAGE_CACHE_SHIFT;
		end = wbc->end >> PAGE_CACHE_SHIFT;
		is_range = 1;
		scanned = 1;
	}
retry:
	while (!done && (index <= end) &&
	       (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
			PAGECACHE_TAG_DIRTY,
			min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) {
		int first;
		unsigned int i;

		first = -1;
		next = 0;
		n_iov = 0;
		bytes_to_write = 0;

		for (i = 0; i < nr_pages; i++) {
			page = pvec.pages[i];
			/*
			 * At this point we hold neither mapping->tree_lock nor
			 * lock on the page itself: the page may be truncated or
			 * invalidated (changing page->mapping to NULL), or even
			 * swizzled back from swapper_space to tmpfs file
			 * mapping
			 */

			if (first < 0)
				lock_page(page);
			else if (TestSetPageLocked(page))
				break;

			if (unlikely(page->mapping != mapping)) {
				unlock_page(page);
				break;
			}

			if (unlikely(is_range) && (page->index > end)) {
				done = 1;
				unlock_page(page);
				break;
			}

			if (next && (page->index != next)) {
				/* Not next consecutive page */
				unlock_page(page);
				break;
			}

			if (wbc->sync_mode != WB_SYNC_NONE)
				wait_on_page_writeback(page);

			if (PageWriteback(page) ||
					!test_clear_page_dirty(page)) {
				unlock_page(page);
				break;
			}
1147 1148 1149 1150 1151 1152 1153

			if (page_offset(page) >= mapping->host->i_size) {
				done = 1;
				unlock_page(page);
				break;
			}

1154 1155 1156 1157 1158
			/*
			 * BB can we get rid of this?  pages are held by pvec
			 */
			page_cache_get(page);

1159 1160 1161
			len = min(mapping->host->i_size - page_offset(page),
				  (loff_t)PAGE_CACHE_SIZE);

1162 1163 1164
			/* reserve iov[0] for the smb header */
			n_iov++;
			iov[n_iov].iov_base = kmap(page);
1165 1166
			iov[n_iov].iov_len = len;
			bytes_to_write += len;
1167 1168 1169 1170 1171 1172 1173 1174 1175 1176

			if (first < 0) {
				first = i;
				offset = page_offset(page);
			}
			next = page->index + 1;
			if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize)
				break;
		}
		if (n_iov) {
1177 1178 1179 1180 1181 1182 1183 1184
			/* Search for a writable handle every time we call
			 * CIFSSMBWrite2.  We can't rely on the last handle
			 * we used to still be valid
			 */
			open_file = find_writable_file(CIFS_I(mapping->host));
			if (!open_file) {
				cERROR(1, ("No writable handles for inode"));
				rc = -EBADF;
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			} else {
1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
				rc = CIFSSMBWrite2(xid, cifs_sb->tcon,
						   open_file->netfid,
						   bytes_to_write, offset,
						   &bytes_written, iov, n_iov,
						   1);
				atomic_dec(&open_file->wrtPending);
				if (rc || bytes_written < bytes_to_write) {
					cERROR(1,("Write2 ret %d, written = %d",
						  rc, bytes_written));
					/* BB what if continued retry is
					   requested via mount flags? */
					set_bit(AS_EIO, &mapping->flags);
				} else {
					cifs_stats_bytes_written(cifs_sb->tcon,
								 bytes_written);
				}
1202 1203 1204
			}
			for (i = 0; i < n_iov; i++) {
				page = pvec.pages[first + i];
1205 1206 1207 1208 1209 1210 1211
				/* Should we also set page error on
				success rc but too little data written? */
				/* BB investigate retry logic on temporary
				server crash cases and how recovery works
				when page marked as error */ 
				if(rc)
					SetPageError(page);
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
				kunmap(page);
				unlock_page(page);
				page_cache_release(page);
			}
			if ((wbc->nr_to_write -= n_iov) <= 0)
				done = 1;
			index = next;
		}
		pagevec_release(&pvec);
	}
	if (!scanned && !done) {
		/*
		 * We hit the last page and there is more work to be done: wrap
		 * back to the start of the file
		 */
		scanned = 1;
		index = 0;
		goto retry;
	}
	if (!is_range)
		mapping->writeback_index = index;

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	FreeXid(xid);
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	return rc;
}

static int cifs_writepage(struct page* page, struct writeback_control *wbc)
{
	int rc = -EFAULT;
	int xid;

	xid = GetXid();
/* BB add check for wbc flags */
	page_cache_get(page);
        if (!PageUptodate(page)) {
		cFYI(1, ("ppw - page not up to date"));
	}
	
	rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE);
	SetPageUptodate(page); /* BB add check for error and Clearuptodate? */
	unlock_page(page);
	page_cache_release(page);	
	FreeXid(xid);
	return rc;
}

static int cifs_commit_write(struct file *file, struct page *page,
	unsigned offset, unsigned to)
{
	int xid;
	int rc = 0;
	struct inode *inode = page->mapping->host;
	loff_t position = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
	char *page_data;

	xid = GetXid();
	cFYI(1, ("commit write for page %p up to position %lld for %d", 
		 page, position, to));
	if (position > inode->i_size) {
		i_size_write(inode, position);
		/* if (file->private_data == NULL) {
			rc = -EBADF;
		} else {
			open_file = (struct cifsFileInfo *)file->private_data;
			cifs_sb = CIFS_SB(inode->i_sb);
			rc = -EAGAIN;
			while (rc == -EAGAIN) {
				if ((open_file->invalidHandle) && 
				    (!open_file->closePend)) {
					rc = cifs_reopen_file(
						file->f_dentry->d_inode, file);
					if (rc != 0)
						break;
				}
				if (!open_file->closePend) {
					rc = CIFSSMBSetFileSize(xid,
						cifs_sb->tcon, position,
						open_file->netfid,
						open_file->pid, FALSE);
				} else {
					rc = -EBADF;
					break;
				}
			}
			cFYI(1, (" SetEOF (commit write) rc = %d", rc));
		} */
	}
	if (!PageUptodate(page)) {
		position =  ((loff_t)page->index << PAGE_CACHE_SHIFT) + offset;
		/* can not rely on (or let) writepage write this data */
		if (to < offset) {
			cFYI(1, ("Illegal offsets, can not copy from %d to %d",
				offset, to));
			FreeXid(xid);
			return rc;
		}
		/* this is probably better than directly calling
		   partialpage_write since in this function the file handle is
		   known which we might as well	leverage */
		/* BB check if anything else missing out of ppw
		   such as updating last write time */
		page_data = kmap(page);
		rc = cifs_write(file, page_data + offset, to-offset,
				&position);
		if (rc > 0)
			rc = 0;
		/* else if (rc < 0) should we set writebehind rc? */
		kunmap(page);
	} else {	
		set_page_dirty(page);
	}

	FreeXid(xid);
	return rc;
}

int cifs_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	int xid;
	int rc = 0;
	struct inode *inode = file->f_dentry->d_inode;

	xid = GetXid();

	cFYI(1, ("Sync file - name: %s datasync: 0x%x ", 
		dentry->d_name.name, datasync));
	
	rc = filemap_fdatawrite(inode->i_mapping);
	if (rc == 0)
		CIFS_I(inode)->write_behind_rc = 0;
	FreeXid(xid);
	return rc;
}

/* static int cifs_sync_page(struct page *page)
{
	struct address_space *mapping;
	struct inode *inode;
	unsigned long index = page->index;
	unsigned int rpages = 0;
	int rc = 0;

	cFYI(1, ("sync page %p",page));
	mapping = page->mapping;
	if (!mapping)
		return 0;
	inode = mapping->host;
	if (!inode)
		return 0; */

/*	fill in rpages then 
	result = cifs_pagein_inode(inode, index, rpages); */ /* BB finish */

/*	cFYI(1, ("rpages is %d for sync page of Index %ld ", rpages, index));

	if (rc < 0)
		return rc;
	return 0;
} */

/*
 * As file closes, flush all cached write data for this inode checking
 * for write behind errors.
 */
int cifs_flush(struct file *file)
{
	struct inode * inode = file->f_dentry->d_inode;
	int rc = 0;

	/* Rather than do the steps manually:
	   lock the inode for writing
	   loop through pages looking for write behind data (dirty pages)
	   coalesce into contiguous 16K (or smaller) chunks to write to server
	   send to server (prefer in parallel)
	   deal with writebehind errors
	   unlock inode for writing
	   filemapfdatawrite appears easier for the time being */

	rc = filemap_fdatawrite(inode->i_mapping);
	if (!rc) /* reset wb rc if we were able to write out dirty pages */
		CIFS_I(inode)->write_behind_rc = 0;
		
	cFYI(1, ("Flush inode %p file %p rc %d",inode,file,rc));

	return rc;
}

ssize_t cifs_user_read(struct file *file, char __user *read_data,
	size_t read_size, loff_t *poffset)
{
	int rc = -EACCES;
	unsigned int bytes_read = 0;
	unsigned int total_read = 0;
	unsigned int current_read_size;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid;
	struct cifsFileInfo *open_file;
	char *smb_read_data;
	char __user *current_offset;
	struct smb_com_read_rsp *pSMBr;

	xid = GetXid();
	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;

	if ((file->f_flags & O_ACCMODE) == O_WRONLY) {
		cFYI(1, ("attempting read on write only file instance"));
	}
	for (total_read = 0, current_offset = read_data;
	     read_size > total_read;
	     total_read += bytes_read, current_offset += bytes_read) {
		current_read_size = min_t(const int, read_size - total_read, 
					  cifs_sb->rsize);
		rc = -EAGAIN;
		smb_read_data = NULL;
		while (rc == -EAGAIN) {
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			int buf_type = CIFS_NO_BUFFER;
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			if ((open_file->invalidHandle) && 
			    (!open_file->closePend)) {
				rc = cifs_reopen_file(file->f_dentry->d_inode,
					file, TRUE);
				if (rc != 0)
					break;
			}
1444
			rc = CIFSSMBRead(xid, pTcon,
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					 open_file->netfid,
					 current_read_size, *poffset,
					 &bytes_read, &smb_read_data,
					 &buf_type);
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			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
			if (smb_read_data) {
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				if (copy_to_user(current_offset,
						smb_read_data +
						4 /* RFC1001 length field */ +
						le16_to_cpu(pSMBr->DataOffset),
						bytes_read)) {
					rc = -EFAULT;
				}

1459 1460 1461 1462
				if(buf_type == CIFS_SMALL_BUFFER)
					cifs_small_buf_release(smb_read_data);
				else if(buf_type == CIFS_LARGE_BUFFER)
					cifs_buf_release(smb_read_data);
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				smb_read_data = NULL;
			}
		}
		if (rc || (bytes_read == 0)) {
			if (total_read) {
				break;
			} else {
				FreeXid(xid);
				return rc;
			}
		} else {
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			cifs_stats_bytes_read(pTcon, bytes_read);
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			*poffset += bytes_read;
		}
	}
	FreeXid(xid);
	return total_read;
}


static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
	loff_t *poffset)
{
	int rc = -EACCES;
	unsigned int bytes_read = 0;
	unsigned int total_read;
	unsigned int current_read_size;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int xid;
	char *current_offset;
	struct cifsFileInfo *open_file;
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	int buf_type = CIFS_NO_BUFFER;
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	xid = GetXid();
	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	pTcon = cifs_sb->tcon;

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;

	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
		cFYI(1, ("attempting read on write only file instance"));

	for (total_read = 0, current_offset = read_data; 
	     read_size > total_read;
	     total_read += bytes_read, current_offset += bytes_read) {
		current_read_size = min_t(const int, read_size - total_read,
					  cifs_sb->rsize);
1515 1516 1517 1518 1519 1520 1521
		/* For windows me and 9x we do not want to request more
		than it negotiated since it will refuse the read then */
		if((pTcon->ses) && 
			!(pTcon->ses->capabilities & CAP_LARGE_FILES)) {
			current_read_size = min_t(const int, current_read_size,
					pTcon->ses->server->maxBuf - 128);
		}
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		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if ((open_file->invalidHandle) && 
			    (!open_file->closePend)) {
				rc = cifs_reopen_file(file->f_dentry->d_inode,
					file, TRUE);
				if (rc != 0)
					break;
			}
1531
			rc = CIFSSMBRead(xid, pTcon,
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					 open_file->netfid,
					 current_read_size, *poffset,
					 &bytes_read, &current_offset,
					 &buf_type);
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		}
		if (rc || (bytes_read == 0)) {
			if (total_read) {
				break;
			} else {
				FreeXid(xid);
				return rc;
			}
		} else {
1545
			cifs_stats_bytes_read(pTcon, total_read);
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			*poffset += bytes_read;
		}
	}
	FreeXid(xid);
	return total_read;
}

int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct dentry *dentry = file->f_dentry;
	int rc, xid;

	xid = GetXid();
	rc = cifs_revalidate(dentry);
	if (rc) {
		cFYI(1, ("Validation prior to mmap failed, error=%d", rc));
		FreeXid(xid);
		return rc;
	}
	rc = generic_file_mmap(file, vma);
	FreeXid(xid);
	return rc;
}


static void cifs_copy_cache_pages(struct address_space *mapping, 
	struct list_head *pages, int bytes_read, char *data,
	struct pagevec *plru_pvec)
{
	struct page *page;
	char *target;

	while (bytes_read > 0) {
		if (list_empty(pages))
			break;

		page = list_entry(pages->prev, struct page, lru);
		list_del(&page->lru);

		if (add_to_page_cache(page, mapping, page->index,
				      GFP_KERNEL)) {
			page_cache_release(page);
			cFYI(1, ("Add page cache failed"));
1589 1590
			data += PAGE_CACHE_SIZE;
			bytes_read -= PAGE_CACHE_SIZE;
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			continue;
		}

		target = kmap_atomic(page,KM_USER0);

		if (PAGE_CACHE_SIZE > bytes_read) {
			memcpy(target, data, bytes_read);
			/* zero the tail end of this partial page */
			memset(target + bytes_read, 0, 
			       PAGE_CACHE_SIZE - bytes_read);
			bytes_read = 0;
		} else {
			memcpy(target, data, PAGE_CACHE_SIZE);
			bytes_read -= PAGE_CACHE_SIZE;
		}
		kunmap_atomic(target, KM_USER0);

		flush_dcache_page(page);
		SetPageUptodate(page);
		unlock_page(page);
		if (!pagevec_add(plru_pvec, page))
			__pagevec_lru_add(plru_pvec);
		data += PAGE_CACHE_SIZE;
	}
	return;
}

static int cifs_readpages(struct file *file, struct address_space *mapping,
	struct list_head *page_list, unsigned num_pages)
{
	int rc = -EACCES;
	int xid;
	loff_t offset;
	struct page *page;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	int bytes_read = 0;
	unsigned int read_size,i;
	char *smb_read_data = NULL;
	struct smb_com_read_rsp *pSMBr;
	struct pagevec lru_pvec;
	struct cifsFileInfo *open_file;
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	int buf_type = CIFS_NO_BUFFER;
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	xid = GetXid();
	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}
	open_file = (struct cifsFileInfo *)file->private_data;
	cifs_sb = CIFS_SB(file->f_dentry->d_sb);
	pTcon = cifs_sb->tcon;
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	pagevec_init(&lru_pvec, 0);

	for (i = 0; i < num_pages; ) {
		unsigned contig_pages;
		struct page *tmp_page;
		unsigned long expected_index;

		if (list_empty(page_list))
			break;

		page = list_entry(page_list->prev, struct page, lru);
		offset = (loff_t)page->index << PAGE_CACHE_SHIFT;

		/* count adjacent pages that we will read into */
		contig_pages = 0;
		expected_index = 
			list_entry(page_list->prev, struct page, lru)->index;
		list_for_each_entry_reverse(tmp_page,page_list,lru) {
			if (tmp_page->index == expected_index) {
				contig_pages++;
				expected_index++;
			} else
				break; 
		}
		if (contig_pages + i >  num_pages)
			contig_pages = num_pages - i;

		/* for reads over a certain size could initiate async
		   read ahead */

		read_size = contig_pages * PAGE_CACHE_SIZE;
		/* Read size needs to be in multiples of one page */
		read_size = min_t(const unsigned int, read_size,
				  cifs_sb->rsize & PAGE_CACHE_MASK);

		rc = -EAGAIN;
		while (rc == -EAGAIN) {
			if ((open_file->invalidHandle) && 
			    (!open_file->closePend)) {
				rc = cifs_reopen_file(file->f_dentry->d_inode,
					file, TRUE);
				if (rc != 0)
					break;
			}

1689
			rc = CIFSSMBRead(xid, pTcon,
1690 1691 1692 1693
					 open_file->netfid,
					 read_size, offset,
					 &bytes_read, &smb_read_data,
					 &buf_type);
1694
			/* BB more RC checks ? */
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			if (rc== -EAGAIN) {
				if (smb_read_data) {
1697 1698 1699 1700
					if(buf_type == CIFS_SMALL_BUFFER)
						cifs_small_buf_release(smb_read_data);
					else if(buf_type == CIFS_LARGE_BUFFER)
						cifs_buf_release(smb_read_data);
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					smb_read_data = NULL;
				}
			}
		}
		if ((rc < 0) || (smb_read_data == NULL)) {
			cFYI(1, ("Read error in readpages: %d", rc));
			/* clean up remaing pages off list */
			while (!list_empty(page_list) && (i < num_pages)) {
				page = list_entry(page_list->prev, struct page,
						  lru);
				list_del(&page->lru);
				page_cache_release(page);
			}
			break;
		} else if (bytes_read > 0) {
			pSMBr = (struct smb_com_read_rsp *)smb_read_data;
			cifs_copy_cache_pages(mapping, page_list, bytes_read,
				smb_read_data + 4 /* RFC1001 hdr */ +
				le16_to_cpu(pSMBr->DataOffset), &lru_pvec);

			i +=  bytes_read >> PAGE_CACHE_SHIFT;
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			cifs_stats_bytes_read(pTcon, bytes_read);
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			if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) {
				i++; /* account for partial page */

				/* server copy of file can have smaller size 
				   than client */
				/* BB do we need to verify this common case ? 
				   this case is ok - if we are at server EOF 
				   we will hit it on next read */

			/* while (!list_empty(page_list) && (i < num_pages)) {
					page = list_entry(page_list->prev, 
							  struct page, list);
					list_del(&page->list);
					page_cache_release(page);
				}
				break; */
			}
		} else {
			cFYI(1, ("No bytes read (%d) at offset %lld . "
				 "Cleaning remaining pages from readahead list",
				 bytes_read, offset));
			/* BB turn off caching and do new lookup on 
			   file size at server? */
			while (!list_empty(page_list) && (i < num_pages)) {
				page = list_entry(page_list->prev, struct page,
						  lru);
				list_del(&page->lru);

				/* BB removeme - replace with zero of page? */
				page_cache_release(page);
			}
			break;
		}
		if (smb_read_data) {
1757 1758 1759 1760
			if(buf_type == CIFS_SMALL_BUFFER)
				cifs_small_buf_release(smb_read_data);
			else if(buf_type == CIFS_LARGE_BUFFER)
				cifs_buf_release(smb_read_data);
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			smb_read_data = NULL;
		}
		bytes_read = 0;
	}

	pagevec_lru_add(&lru_pvec);

/* need to free smb_read_data buf before exit */
	if (smb_read_data) {
1770 1771 1772 1773
		if(buf_type == CIFS_SMALL_BUFFER)
			cifs_small_buf_release(smb_read_data);
		else if(buf_type == CIFS_LARGE_BUFFER)
			cifs_buf_release(smb_read_data);
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		smb_read_data = NULL;
	} 

	FreeXid(xid);
	return rc;
}

static int cifs_readpage_worker(struct file *file, struct page *page,
	loff_t *poffset)
{
	char *read_data;
	int rc;

	page_cache_get(page);
	read_data = kmap(page);
	/* for reads over a certain size could initiate async read ahead */
                                                                                                                           
	rc = cifs_read(file, read_data, PAGE_CACHE_SIZE, poffset);
                                                                                                                           
	if (rc < 0)
		goto io_error;
	else
		cFYI(1, ("Bytes read %d ",rc));
                                                                                                                           
	file->f_dentry->d_inode->i_atime =
		current_fs_time(file->f_dentry->d_inode->i_sb);
                                                                                                                           
	if (PAGE_CACHE_SIZE > rc)
		memset(read_data + rc, 0, PAGE_CACHE_SIZE - rc);

	flush_dcache_page(page);
	SetPageUptodate(page);
	rc = 0;
                                                                                                                           
io_error:
        kunmap(page);
	page_cache_release(page);
	return rc;
}

static int cifs_readpage(struct file *file, struct page *page)
{
	loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	int rc = -EACCES;
	int xid;

	xid = GetXid();

	if (file->private_data == NULL) {
		FreeXid(xid);
		return -EBADF;
	}

	cFYI(1, ("readpage %p at offset %d 0x%x\n", 
		 page, (int)offset, (int)offset));

	rc = cifs_readpage_worker(file, page, &offset);

	unlock_page(page);

	FreeXid(xid);
	return rc;
}

/* We do not want to update the file size from server for inodes
   open for write - to avoid races with writepage extending
   the file - in the future we could consider allowing
   refreshing the inode only on increases in the file size 
   but this is tricky to do without racing with writebehind
   page caching in the current Linux kernel design */
int is_size_safe_to_change(struct cifsInodeInfo *cifsInode)
{
1846 1847 1848 1849 1850 1851
	struct cifsFileInfo *open_file = NULL;

	if (cifsInode)
		open_file =  find_writable_file(cifsInode);
 
	if(open_file) {
1852 1853
		struct cifs_sb_info *cifs_sb;

1854 1855 1856 1857
		/* there is not actually a write pending so let
		this handle go free and allow it to
		be closable if needed */
		atomic_dec(&open_file->wrtPending);
1858 1859 1860 1861 1862 1863 1864 1865

		cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
		if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
			/* since no page cache to corrupt on directio 
			we can change size safely */
			return 1;
		}

1866
		return 0;
1867
	} else
1868
		return 1;
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}

static int cifs_prepare_write(struct file *file, struct page *page,
	unsigned from, unsigned to)
{
	int rc = 0;
        loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
	cFYI(1, ("prepare write for page %p from %d to %d",page,from,to));
	if (!PageUptodate(page)) {
	/*	if (to - from != PAGE_CACHE_SIZE) {
			void *kaddr = kmap_atomic(page, KM_USER0);
			memset(kaddr, 0, from);
			memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
			flush_dcache_page(page);
			kunmap_atomic(kaddr, KM_USER0);
		} */
		/* If we are writing a full page it will be up to date,
		   no need to read from the server */
		if ((to == PAGE_CACHE_SIZE) && (from == 0))
			SetPageUptodate(page);

		/* might as well read a page, it is fast enough */
		if ((file->f_flags & O_ACCMODE) != O_WRONLY) {
			rc = cifs_readpage_worker(file, page, &offset);
		} else {
		/* should we try using another file handle if there is one -
		   how would we lock it to prevent close of that handle
		   racing with this read?
		   In any case this will be written out by commit_write */
		}
	}

	/* BB should we pass any errors back? 
	   e.g. if we do not have read access to the file */
	return 0;
}

struct address_space_operations cifs_addr_ops = {
	.readpage = cifs_readpage,
	.readpages = cifs_readpages,
	.writepage = cifs_writepage,
1910
	.writepages = cifs_writepages,
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	.prepare_write = cifs_prepare_write,
	.commit_write = cifs_commit_write,
	.set_page_dirty = __set_page_dirty_nobuffers,
	/* .sync_page = cifs_sync_page, */
	/* .direct_IO = */
};