diff options
Diffstat (limited to 'fs/cifs/file.c')
| -rw-r--r-- | fs/cifs/file.c | 1675 |
1 files changed, 1675 insertions, 0 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c new file mode 100644 index 000000000000..dcab7cf1b53b --- /dev/null +++ b/fs/cifs/file.c @@ -0,0 +1,1675 @@ +/* + * 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> +#include <linux/stat.h> +#include <linux/fcntl.h> +#include <linux/pagemap.h> +#include <linux/pagevec.h> +#include <linux/smp_lock.h> +#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; + + 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? */ + filemap_fdatawrite(file->f_dentry->d_inode->i_mapping); + filemap_fdatawait(file->f_dentry->d_inode->i_mapping); + } + 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); + full_path = build_path_from_dentry(file->f_dentry); + 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, + cifs_sb->local_nls); + 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 */, + cifs_sb->local_nls); + } 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 */ + full_path = build_path_from_dentry(file->f_dentry); + 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, + cifs_sb->local_nls); + 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) { + filemap_fdatawrite(inode->i_mapping); + filemap_fdatawait(inode->i_mapping); + /* 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) { + write_unlock(&file->f_owner.lock); + rc = CIFSSMBClose(xid, pTcon, + pSMBFile->netfid); + write_lock(&file->f_owner.lock); + } + } + list_del(&pSMBFile->flist); + list_del(&pSMBFile->tlist); + 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")); + if (pCFileStruct->srch_inf.endOfSearch == FALSE) { + 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) { + /* BB removeme BB */ cFYI(1, ("freeing smb buf in srch struct in closedir")); + pCFileStruct->srch_inf.ntwrk_buf_start = NULL; + cifs_buf_release(ptmp); + } + ptmp = pCFileStruct->search_resume_name; + if (ptmp) { + /* BB removeme BB */ cFYI(1, ("freeing resume name in closedir")); + 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) + cFYI(1, ("Posix ")); + if (pfLock->fl_flags & FL_FLOCK) + cFYI(1, ("Flock ")); + if (pfLock->fl_flags & FL_SLEEP) { + cFYI(1, ("Blocking lock ")); + 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) { + cFYI(1, ("F_UNLCK ")); + numUnlock = 1; + } else if (pfLock->fl_type == F_RDLCK) { + cFYI(1, ("F_RDLCK ")); + lockType |= LOCKING_ANDX_SHARED_LOCK; + numLock = 1; + } else if (pfLock->fl_type == F_EXLCK) { + cFYI(1, ("F_EXLCK ")); + numLock = 1; + } else if (pfLock->fl_type == F_SHLCK) { + cFYI(1, ("F_SHLCK ")); + lockType |= LOCKING_ANDX_SHARED_LOCK; + numLock = 1; + } else + cFYI(1, ("Unknown type of lock ")); + + 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); + if (rc == 0 && (pfLock->fl_flags & FL_POSIX)) + 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 */ + } + +#ifdef CONFIG_CIFS_STATS + if (total_written > 0) { + atomic_inc(&pTcon->num_writes); + spin_lock(&pTcon->stat_lock); + pTcon->bytes_written += total_written; + spin_unlock(&pTcon->stat_lock); + } +#endif + + /* 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; + + /* 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, + 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 */ + } + +#ifdef CONFIG_CIFS_STATS + if (total_written > 0) { + atomic_inc(&pTcon->num_writes); + spin_lock(&pTcon->stat_lock); + pTcon->bytes_written += total_written; + spin_unlock(&pTcon->stat_lock); + } +#endif + + /* 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; +} + +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; + struct cifsInodeInfo *cifsInode; + struct cifsFileInfo *open_file = NULL; + struct list_head *tmp; + struct list_head *tmp1; + + 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); + + cifsInode = CIFS_I(mapping->host); + read_lock(&GlobalSMBSeslock); + /* BB we should start at the end */ + list_for_each_safe(tmp, tmp1, &cifsInode->openFileList) { + open_file = list_entry(tmp, struct cifsFileInfo, flist); + if (open_file->closePend) + continue; + /* We check if file is open for writing first */ + if ((open_file->pfile) && + ((open_file->pfile->f_flags & O_RDWR) || + (open_file->pfile->f_flags & O_WRONLY))) { + read_unlock(&GlobalSMBSeslock); + bytes_written = cifs_write(open_file->pfile, + write_data, to-from, + &offset); + read_lock(&GlobalSMBSeslock); + /* Does mm or vfs already set times? */ + 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) { + /* have seen a case in which kernel seemed to + have closed/freed a file even with writes + active so we might as well see if there are + other file structs to try for the same + inode before giving up */ + continue; + } else + rc = bytes_written; + } + break; /* now that we found a valid file handle and + tried to write to it we are done, no sense + continuing to loop looking for another */ + } + if (tmp->next == NULL) { + cFYI(1, ("File instance %p removed", tmp)); + break; + } + } + read_unlock(&GlobalSMBSeslock); + if (open_file == NULL) { + cFYI(1, ("No writeable filehandles for inode")); + rc = -EIO; + } + + kunmap(page); + return rc; +} + +#if 0 +static int cifs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + int rc = -EFAULT; + int xid; + + xid = GetXid(); + + /* Find contiguous pages then iterate through repeating + call 16K write then Setpageuptodate or if LARGE_WRITE_X + support then send larger writes via kevec so as to eliminate + a memcpy */ + FreeXid(xid); + return rc; +} +#endif + +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) { + if ((open_file->invalidHandle) && + (!open_file->closePend)) { + rc = cifs_reopen_file(file->f_dentry->d_inode, + file, TRUE); + if (rc != 0) + break; + } + + rc = CIFSSMBRead(xid, pTcon, + open_file->netfid, + current_read_size, *poffset, + &bytes_read, &smb_read_data); + + pSMBr = (struct smb_com_read_rsp *)smb_read_data; + if (copy_to_user(current_offset, + smb_read_data + 4 /* RFC1001 hdr */ + + le16_to_cpu(pSMBr->DataOffset), + bytes_read)) { + rc = -EFAULT; + FreeXid(xid); + return rc; + } + if (smb_read_data) { + cifs_buf_release(smb_read_data); + smb_read_data = NULL; + } + } + if (rc || (bytes_read == 0)) { + if (total_read) { + break; + } else { + FreeXid(xid); + return rc; + } + } else { +#ifdef CONFIG_CIFS_STATS + atomic_inc(&pTcon->num_reads); + spin_lock(&pTcon->stat_lock); + pTcon->bytes_read += total_read; + spin_unlock(&pTcon->stat_lock); +#endif + *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; + + 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; + 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; + } + + rc = CIFSSMBRead(xid, pTcon, + open_file->netfid, + current_read_size, *poffset, + &bytes_read, ¤t_offset); + } + if (rc || (bytes_read == 0)) { + if (total_read) { + break; + } else { + FreeXid(xid); + return rc; + } + } else { +#ifdef CONFIG_CIFS_STATS + atomic_inc(&pTcon->num_reads); + spin_lock(&pTcon->stat_lock); + pTcon->bytes_read += total_read; + spin_unlock(&pTcon->stat_lock); +#endif + *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")); + 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; + + 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; + + 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; + } + + rc = CIFSSMBRead(xid, pTcon, + open_file->netfid, + read_size, offset, + &bytes_read, &smb_read_data); + /* BB need to check return code here */ + if (rc== -EAGAIN) { + if (smb_read_data) { + cifs_buf_release(smb_read_data); + 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; +#ifdef CONFIG_CIFS_STATS + atomic_inc(&pTcon->num_reads); + spin_lock(&pTcon->stat_lock); + pTcon->bytes_read += bytes_read; + spin_unlock(&pTcon->stat_lock); +#endif + 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) { + cifs_buf_release(smb_read_data); + 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) { + cifs_buf_release(smb_read_data); + 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) +{ + struct list_head *tmp; + struct list_head *tmp1; + struct cifsFileInfo *open_file = NULL; + int rc = TRUE; + + if (cifsInode == NULL) + return rc; + + read_lock(&GlobalSMBSeslock); + list_for_each_safe(tmp, tmp1, &cifsInode->openFileList) { + open_file = list_entry(tmp, struct cifsFileInfo, flist); + if (open_file == NULL) + break; + if (open_file->closePend) + continue; + /* We check if file is open for writing, + BB we could supplement this with a check to see if file size + changes have been flushed to server - ie inode metadata dirty */ + if ((open_file->pfile) && + ((open_file->pfile->f_flags & O_RDWR) || + (open_file->pfile->f_flags & O_WRONLY))) { + rc = FALSE; + break; + } + if (tmp->next == NULL) { + cFYI(1, ("File instance %p removed", tmp)); + break; + } + } + read_unlock(&GlobalSMBSeslock); + return rc; +} + + +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, + .prepare_write = cifs_prepare_write, + .commit_write = cifs_commit_write, + .set_page_dirty = __set_page_dirty_nobuffers, + /* .sync_page = cifs_sync_page, */ + /* .direct_IO = */ +}; |