| /* |
| * fs/cifs/file.c |
| * |
| * vfs operations that deal with files |
| * |
| * Copyright (C) International Business Machines Corp., 2002,2010 |
| * Author(s): Steve French (sfrench@us.ibm.com) |
| * Jeremy Allison (jra@samba.org) |
| * |
| * 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/backing-dev.h> |
| #include <linux/stat.h> |
| #include <linux/fcntl.h> |
| #include <linux/pagemap.h> |
| #include <linux/pagevec.h> |
| #include <linux/writeback.h> |
| #include <linux/task_io_accounting_ops.h> |
| #include <linux/delay.h> |
| #include <linux/mount.h> |
| #include <linux/slab.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" |
| #include "fscache.h" |
| |
| 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 (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES | |
| FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA | |
| FILE_READ_DATA); |
| } |
| |
| static inline fmode_t cifs_posix_convert_flags(unsigned int flags) |
| { |
| fmode_t posix_flags = 0; |
| |
| if ((flags & O_ACCMODE) == O_RDONLY) |
| posix_flags = FMODE_READ; |
| else if ((flags & O_ACCMODE) == O_WRONLY) |
| posix_flags = FMODE_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; */ |
| posix_flags = FMODE_READ | FMODE_WRITE; |
| } |
| /* can not map O_CREAT or O_EXCL or O_TRUNC flags when |
| reopening a file. They had their effect on the original open */ |
| if (flags & O_APPEND) |
| posix_flags |= (fmode_t)O_APPEND; |
| if (flags & O_DSYNC) |
| posix_flags |= (fmode_t)O_DSYNC; |
| if (flags & __O_SYNC) |
| posix_flags |= (fmode_t)__O_SYNC; |
| if (flags & O_DIRECTORY) |
| posix_flags |= (fmode_t)O_DIRECTORY; |
| if (flags & O_NOFOLLOW) |
| posix_flags |= (fmode_t)O_NOFOLLOW; |
| if (flags & O_DIRECT) |
| posix_flags |= (fmode_t)O_DIRECT; |
| |
| return posix_flags; |
| } |
| |
| 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 if ((flags & O_TRUNC) == O_TRUNC) |
| return FILE_OVERWRITE; |
| else |
| return FILE_OPEN; |
| } |
| |
| /* all arguments to this function must be checked for validity in caller */ |
| static inline int |
| cifs_posix_open_inode_helper(struct inode *inode, struct file *file, |
| struct cifsInodeInfo *pCifsInode, __u32 oplock, |
| u16 netfid) |
| { |
| |
| write_lock(&GlobalSMBSeslock); |
| |
| pCifsInode = CIFS_I(file->f_path.dentry->d_inode); |
| if (pCifsInode == NULL) { |
| write_unlock(&GlobalSMBSeslock); |
| return -EINVAL; |
| } |
| |
| if (pCifsInode->clientCanCacheRead) { |
| /* we have the inode open somewhere else |
| no need to discard cache data */ |
| goto psx_client_can_cache; |
| } |
| |
| /* BB FIXME need to fix this check to move it earlier into posix_open |
| BB fIX following section BB FIXME */ |
| |
| /* 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_path.dentry->d_inode->i_mtime, &temp) && |
| (file->f_path.dentry->d_inode->i_size == |
| (loff_t)le64_to_cpu(buf->EndOfFile))) { |
| cFYI(1, "inode unchanged on server"); |
| } else { |
| if (file->f_path.dentry->d_inode->i_mapping) { |
| rc = filemap_write_and_wait(file->f_path.dentry->d_inode->i_mapping); |
| if (rc != 0) |
| CIFS_I(file->f_path.dentry->d_inode)->write_behind_rc = rc; |
| } |
| cFYI(1, "invalidating remote inode since open detected it " |
| "changed"); |
| invalidate_remote_inode(file->f_path.dentry->d_inode); |
| } */ |
| |
| psx_client_can_cache: |
| if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) { |
| pCifsInode->clientCanCacheAll = true; |
| pCifsInode->clientCanCacheRead = true; |
| cFYI(1, "Exclusive Oplock granted on inode %p", |
| file->f_path.dentry->d_inode); |
| } else if ((oplock & 0xF) == OPLOCK_READ) |
| pCifsInode->clientCanCacheRead = true; |
| |
| /* will have to change the unlock if we reenable the |
| filemap_fdatawrite (which does not seem necessary */ |
| write_unlock(&GlobalSMBSeslock); |
| return 0; |
| } |
| |
| /* all arguments to this function must be checked for validity in caller */ |
| static inline int cifs_open_inode_helper(struct inode *inode, |
| struct cifsTconInfo *pTcon, __u32 oplock, FILE_ALL_INFO *buf, |
| char *full_path, int xid) |
| { |
| struct cifsInodeInfo *pCifsInode = CIFS_I(inode); |
| struct timespec temp; |
| int rc; |
| |
| 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(buf->LastWriteTime); |
| if (timespec_equal(&inode->i_mtime, &temp) && |
| (inode->i_size == |
| (loff_t)le64_to_cpu(buf->EndOfFile))) { |
| cFYI(1, "inode unchanged on server"); |
| } else { |
| if (inode->i_mapping) { |
| /* BB no need to lock inode until after invalidate |
| since namei code should already have it locked? */ |
| rc = filemap_write_and_wait(inode->i_mapping); |
| if (rc != 0) |
| pCifsInode->write_behind_rc = rc; |
| } |
| cFYI(1, "invalidating remote inode since open detected it " |
| "changed"); |
| invalidate_remote_inode(inode); |
| } |
| |
| client_can_cache: |
| if (pTcon->unix_ext) |
| rc = cifs_get_inode_info_unix(&inode, full_path, inode->i_sb, |
| xid); |
| else |
| rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb, |
| xid, NULL); |
| |
| if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) { |
| pCifsInode->clientCanCacheAll = true; |
| pCifsInode->clientCanCacheRead = true; |
| cFYI(1, "Exclusive Oplock granted on inode %p", 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; |
| __u32 oplock; |
| struct cifs_sb_info *cifs_sb; |
| struct cifsTconInfo *tcon; |
| struct tcon_link *tlink; |
| struct cifsFileInfo *pCifsFile = NULL; |
| struct cifsInodeInfo *pCifsInode; |
| char *full_path = NULL; |
| int desiredAccess; |
| int disposition; |
| __u16 netfid; |
| FILE_ALL_INFO *buf = NULL; |
| |
| xid = GetXid(); |
| |
| cifs_sb = CIFS_SB(inode->i_sb); |
| tlink = cifs_sb_tlink(cifs_sb); |
| if (IS_ERR(tlink)) { |
| FreeXid(xid); |
| return PTR_ERR(tlink); |
| } |
| tcon = tlink_tcon(tlink); |
| |
| pCifsInode = CIFS_I(file->f_path.dentry->d_inode); |
| |
| full_path = build_path_from_dentry(file->f_path.dentry); |
| if (full_path == NULL) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| cFYI(1, "inode = 0x%p file flags are 0x%x for %s", |
| inode, file->f_flags, full_path); |
| |
| if (oplockEnabled) |
| oplock = REQ_OPLOCK; |
| else |
| oplock = 0; |
| |
| if (!tcon->broken_posix_open && tcon->unix_ext && |
| (tcon->ses->capabilities & CAP_UNIX) && |
| (CIFS_UNIX_POSIX_PATH_OPS_CAP & |
| le64_to_cpu(tcon->fsUnixInfo.Capability))) { |
| int oflags = (int) cifs_posix_convert_flags(file->f_flags); |
| oflags |= SMB_O_CREAT; |
| /* can not refresh inode info since size could be stale */ |
| rc = cifs_posix_open(full_path, &inode, inode->i_sb, |
| cifs_sb->mnt_file_mode /* ignored */, |
| oflags, &oplock, &netfid, xid); |
| if (rc == 0) { |
| cFYI(1, "posix open succeeded"); |
| /* no need for special case handling of setting mode |
| on read only files needed here */ |
| |
| rc = cifs_posix_open_inode_helper(inode, file, |
| pCifsInode, oplock, netfid); |
| if (rc != 0) { |
| CIFSSMBClose(xid, tcon, netfid); |
| goto out; |
| } |
| |
| pCifsFile = cifs_new_fileinfo(inode, netfid, file, |
| file->f_path.mnt, |
| tlink, oflags, oplock); |
| if (pCifsFile == NULL) { |
| CIFSSMBClose(xid, tcon, netfid); |
| rc = -ENOMEM; |
| } |
| |
| cifs_fscache_set_inode_cookie(inode, file); |
| |
| goto out; |
| } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) { |
| if (tcon->ses->serverNOS) |
| cERROR(1, "server %s of type %s returned" |
| " unexpected error on SMB posix open" |
| ", disabling posix open support." |
| " Check if server update available.", |
| tcon->ses->serverName, |
| tcon->ses->serverNOS); |
| tcon->broken_posix_open = true; |
| } else if ((rc != -EIO) && (rc != -EREMOTE) && |
| (rc != -EOPNOTSUPP)) /* path not found or net err */ |
| goto out; |
| /* else fallthrough to retry open the old way on network i/o |
| or DFS errors */ |
| } |
| |
| 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); |
| |
| /* 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; |
| } |
| |
| if (tcon->ses->capabilities & CAP_NT_SMBS) |
| rc = CIFSSMBOpen(xid, tcon, full_path, disposition, |
| desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf, |
| cifs_sb->local_nls, cifs_sb->mnt_cifs_flags |
| & CIFS_MOUNT_MAP_SPECIAL_CHR); |
| else |
| rc = -EIO; /* no NT SMB support fall into legacy open below */ |
| |
| if (rc == -EIO) { |
| /* Old server, try legacy style OpenX */ |
| rc = SMBLegacyOpen(xid, tcon, full_path, disposition, |
| desiredAccess, CREATE_NOT_DIR, &netfid, &oplock, buf, |
| cifs_sb->local_nls, cifs_sb->mnt_cifs_flags |
| & CIFS_MOUNT_MAP_SPECIAL_CHR); |
| } |
| if (rc) { |
| cFYI(1, "cifs_open returned 0x%x", rc); |
| goto out; |
| } |
| |
| rc = cifs_open_inode_helper(inode, tcon, oplock, buf, full_path, xid); |
| if (rc != 0) |
| goto out; |
| |
| pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt, |
| tlink, file->f_flags, oplock); |
| if (pCifsFile == NULL) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| cifs_fscache_set_inode_cookie(inode, file); |
| |
| if (oplock & CIFS_CREATE_ACTION) { |
| /* time to set mode which we can not set earlier due to |
| problems creating new read-only files */ |
| if (tcon->unix_ext) { |
| struct cifs_unix_set_info_args args = { |
| .mode = inode->i_mode, |
| .uid = NO_CHANGE_64, |
| .gid = NO_CHANGE_64, |
| .ctime = NO_CHANGE_64, |
| .atime = NO_CHANGE_64, |
| .mtime = NO_CHANGE_64, |
| .device = 0, |
| }; |
| CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args, |
| cifs_sb->local_nls, |
| cifs_sb->mnt_cifs_flags & |
| CIFS_MOUNT_MAP_SPECIAL_CHR); |
| } |
| } |
| |
| out: |
| kfree(buf); |
| kfree(full_path); |
| FreeXid(xid); |
| cifs_put_tlink(tlink); |
| return rc; |
| } |
| |
| /* Try to reacquire 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 file *file, bool can_flush) |
| { |
| int rc = -EACCES; |
| int xid; |
| __u32 oplock; |
| struct cifs_sb_info *cifs_sb; |
| struct cifsTconInfo *tcon; |
| struct cifsFileInfo *pCifsFile; |
| struct cifsInodeInfo *pCifsInode; |
| struct inode *inode; |
| char *full_path = NULL; |
| int desiredAccess; |
| int disposition = FILE_OPEN; |
| __u16 netfid; |
| |
| if (file->private_data) |
| pCifsFile = file->private_data; |
| else |
| return -EBADF; |
| |
| xid = GetXid(); |
| mutex_lock(&pCifsFile->fh_mutex); |
| if (!pCifsFile->invalidHandle) { |
| mutex_unlock(&pCifsFile->fh_mutex); |
| rc = 0; |
| FreeXid(xid); |
| return rc; |
| } |
| |
| if (file->f_path.dentry == NULL) { |
| cERROR(1, "no valid name if dentry freed"); |
| dump_stack(); |
| rc = -EBADF; |
| goto reopen_error_exit; |
| } |
| |
| inode = file->f_path.dentry->d_inode; |
| if (inode == NULL) { |
| cERROR(1, "inode not valid"); |
| dump_stack(); |
| rc = -EBADF; |
| goto reopen_error_exit; |
| } |
| |
| cifs_sb = CIFS_SB(inode->i_sb); |
| tcon = tlink_tcon(pCifsFile->tlink); |
| |
| /* 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_path.dentry); |
| if (full_path == NULL) { |
| rc = -ENOMEM; |
| reopen_error_exit: |
| mutex_unlock(&pCifsFile->fh_mutex); |
| FreeXid(xid); |
| return rc; |
| } |
| |
| cFYI(1, "inode = 0x%p file flags 0x%x for %s", |
| inode, file->f_flags, full_path); |
| |
| if (oplockEnabled) |
| oplock = REQ_OPLOCK; |
| else |
| oplock = 0; |
| |
| if (tcon->unix_ext && (tcon->ses->capabilities & CAP_UNIX) && |
| (CIFS_UNIX_POSIX_PATH_OPS_CAP & |
| le64_to_cpu(tcon->fsUnixInfo.Capability))) { |
| int oflags = (int) cifs_posix_convert_flags(file->f_flags); |
| /* can not refresh inode info since size could be stale */ |
| rc = cifs_posix_open(full_path, NULL, inode->i_sb, |
| cifs_sb->mnt_file_mode /* ignored */, |
| oflags, &oplock, &netfid, xid); |
| if (rc == 0) { |
| cFYI(1, "posix reopen succeeded"); |
| goto reopen_success; |
| } |
| /* fallthrough to retry open the old way on errors, especially |
| in the reconnect path it is important to retry hard */ |
| } |
| |
| desiredAccess = cifs_convert_flags(file->f_flags); |
| |
| /* 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 */ |
| |
| rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess, |
| CREATE_NOT_DIR, &netfid, &oplock, NULL, |
| cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & |
| CIFS_MOUNT_MAP_SPECIAL_CHR); |
| if (rc) { |
| mutex_unlock(&pCifsFile->fh_mutex); |
| cFYI(1, "cifs_open returned 0x%x", rc); |
| cFYI(1, "oplock: %d", oplock); |
| } else { |
| reopen_success: |
| pCifsFile->netfid = netfid; |
| pCifsFile->invalidHandle = false; |
| mutex_unlock(&pCifsFile->fh_mutex); |
| pCifsInode = CIFS_I(inode); |
| if (pCifsInode) { |
| if (can_flush) { |
| rc = filemap_write_and_wait(inode->i_mapping); |
| if (rc != 0) |
| CIFS_I(inode)->write_behind_rc = rc; |
| /* temporarily disable caching while we |
| go to server to get inode info */ |
| pCifsInode->clientCanCacheAll = false; |
| pCifsInode->clientCanCacheRead = false; |
| if (tcon->unix_ext) |
| 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, NULL); |
| } /* 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_path.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, timeout; |
| struct cifs_sb_info *cifs_sb; |
| struct cifsTconInfo *pTcon; |
| struct cifsFileInfo *pSMBFile = file->private_data; |
| |
| xid = GetXid(); |
| |
| cifs_sb = CIFS_SB(inode->i_sb); |
| pTcon = tlink_tcon(pSMBFile->tlink); |
| if (pSMBFile) { |
| struct cifsLockInfo *li, *tmp; |
| write_lock(&GlobalSMBSeslock); |
| pSMBFile->closePend = true; |
| if (pTcon) { |
| /* no sense reconnecting to close a file that is |
| already closed */ |
| if (!pTcon->need_reconnect) { |
| write_unlock(&GlobalSMBSeslock); |
| timeout = 2; |
| while ((atomic_read(&pSMBFile->count) != 1) |
| && (timeout <= 2048)) { |
| /* 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 */ |
| cFYI(DBG2, "close delay, write pending"); |
| msleep(timeout); |
| timeout *= 4; |
| } |
| if (!pTcon->need_reconnect && |
| !pSMBFile->invalidHandle) |
| rc = CIFSSMBClose(xid, pTcon, |
| pSMBFile->netfid); |
| } else |
| write_unlock(&GlobalSMBSeslock); |
| } else |
| write_unlock(&GlobalSMBSeslock); |
| |
| /* Delete any outstanding lock records. |
| We'll lose them when the file is closed anyway. */ |
| mutex_lock(&pSMBFile->lock_mutex); |
| list_for_each_entry_safe(li, tmp, &pSMBFile->llist, llist) { |
| list_del(&li->llist); |
| kfree(li); |
| } |
| mutex_unlock(&pSMBFile->lock_mutex); |
| |
| write_lock(&GlobalSMBSeslock); |
| list_del(&pSMBFile->flist); |
| list_del(&pSMBFile->tlist); |
| write_unlock(&GlobalSMBSeslock); |
| cifsFileInfo_put(file->private_data); |
| file->private_data = NULL; |
| } else |
| rc = -EBADF; |
| |
| read_lock(&GlobalSMBSeslock); |
| 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; |
| } |
| read_unlock(&GlobalSMBSeslock); |
| 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 = file->private_data; |
| char *ptmp; |
| |
| cFYI(1, "Closedir inode = 0x%p", inode); |
| |
| xid = GetXid(); |
| |
| if (pCFileStruct) { |
| struct cifsTconInfo *pTcon = tlink_tcon(pCFileStruct->tlink); |
| |
| cFYI(1, "Freeing private data in close dir"); |
| write_lock(&GlobalSMBSeslock); |
| if (!pCFileStruct->srch_inf.endOfSearch && |
| !pCFileStruct->invalidHandle) { |
| pCFileStruct->invalidHandle = true; |
| write_unlock(&GlobalSMBSeslock); |
| 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; |
| } else |
| write_unlock(&GlobalSMBSeslock); |
| ptmp = pCFileStruct->srch_inf.ntwrk_buf_start; |
| if (ptmp) { |
| cFYI(1, "closedir free smb buf in srch struct"); |
| pCFileStruct->srch_inf.ntwrk_buf_start = NULL; |
| if (pCFileStruct->srch_inf.smallBuf) |
| cifs_small_buf_release(ptmp); |
| else |
| cifs_buf_release(ptmp); |
| } |
| cifs_put_tlink(pCFileStruct->tlink); |
| kfree(file->private_data); |
| file->private_data = NULL; |
| } |
| /* BB can we lock the filestruct while this is going on? */ |
| FreeXid(xid); |
| return rc; |
| } |
| |
| static int store_file_lock(struct cifsFileInfo *fid, __u64 len, |
| __u64 offset, __u8 lockType) |
| { |
| struct cifsLockInfo *li = |
| kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL); |
| if (li == NULL) |
| return -ENOMEM; |
| li->offset = offset; |
| li->length = len; |
| li->type = lockType; |
| mutex_lock(&fid->lock_mutex); |
| list_add(&li->llist, &fid->llist); |
| mutex_unlock(&fid->lock_mutex); |
| return 0; |
| } |
| |
| int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock) |
| { |
| int rc, xid; |
| __u32 numLock = 0; |
| __u32 numUnlock = 0; |
| __u64 length; |
| bool wait_flag = false; |
| struct cifs_sb_info *cifs_sb; |
| struct cifsTconInfo *tcon; |
| __u16 netfid; |
| __u8 lockType = LOCKING_ANDX_LARGE_FILES; |
| bool posix_locking = 0; |
| |
| 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; |
| /* Check if unlock includes more than |
| one lock range */ |
| } 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_path.dentry->d_sb); |
| tcon = tlink_tcon(((struct cifsFileInfo *)file->private_data)->tlink); |
| |
| if (file->private_data == NULL) { |
| rc = -EBADF; |
| FreeXid(xid); |
| return rc; |
| } |
| netfid = ((struct cifsFileInfo *)file->private_data)->netfid; |
| |
| if ((tcon->ses->capabilities & CAP_UNIX) && |
| (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) && |
| ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) |
| posix_locking = 1; |
| /* BB add code here to normalize offset and length to |
| account for negative length which we can not accept over the |
| wire */ |
| if (IS_GETLK(cmd)) { |
| if (posix_locking) { |
| int posix_lock_type; |
| if (lockType & LOCKING_ANDX_SHARED_LOCK) |
| posix_lock_type = CIFS_RDLCK; |
| else |
| posix_lock_type = CIFS_WRLCK; |
| rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */, |
| length, pfLock, |
| posix_lock_type, wait_flag); |
| FreeXid(xid); |
| return rc; |
| } |
| |
| /* BB we could chain these into one lock request BB */ |
| rc = CIFSSMBLock(xid, tcon, netfid, length, pfLock->fl_start, |
| 0, 1, lockType, 0 /* wait flag */ ); |
| if (rc == 0) { |
| rc = CIFSSMBLock(xid, tcon, 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; |
| |
| if (lockType & LOCKING_ANDX_SHARED_LOCK) { |
| pfLock->fl_type = F_WRLCK; |
| } else { |
| rc = CIFSSMBLock(xid, tcon, netfid, length, |
| pfLock->fl_start, 0, 1, |
| lockType | LOCKING_ANDX_SHARED_LOCK, |
| 0 /* wait flag */); |
| if (rc == 0) { |
| rc = CIFSSMBLock(xid, tcon, netfid, |
| length, pfLock->fl_start, 1, 0, |
| lockType | |
| LOCKING_ANDX_SHARED_LOCK, |
| 0 /* wait flag */); |
| pfLock->fl_type = F_RDLCK; |
| if (rc != 0) |
| cERROR(1, "Error unlocking " |
| "previously locked range %d " |
| "during test of lock", rc); |
| rc = 0; |
| } else { |
| pfLock->fl_type = F_WRLCK; |
| rc = 0; |
| } |
| } |
| } |
| |
| FreeXid(xid); |
| return rc; |
| } |
| |
| if (!numLock && !numUnlock) { |
| /* if no lock or unlock then nothing |
| to do since we do not know what it is */ |
| FreeXid(xid); |
| return -EOPNOTSUPP; |
| } |
| |
| if (posix_locking) { |
| int posix_lock_type; |
| if (lockType & LOCKING_ANDX_SHARED_LOCK) |
| posix_lock_type = CIFS_RDLCK; |
| else |
| posix_lock_type = CIFS_WRLCK; |
| |
| if (numUnlock == 1) |
| posix_lock_type = CIFS_UNLCK; |
| |
| rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */, |
| length, pfLock, |
| posix_lock_type, wait_flag); |
| } else { |
| struct cifsFileInfo *fid = file->private_data; |
| |
| if (numLock) { |
| rc = CIFSSMBLock(xid, tcon, netfid, length, |
| pfLock->fl_start, |
| 0, numLock, lockType, wait_flag); |
| |
| if (rc == 0) { |
| /* For Windows locks we must store them. */ |
| rc = store_file_lock(fid, length, |
| pfLock->fl_start, lockType); |
| } |
| } else if (numUnlock) { |
| /* For each stored lock that this unlock overlaps |
| completely, unlock it. */ |
| int stored_rc = 0; |
| struct cifsLockInfo *li, *tmp; |
| |
| rc = 0; |
| mutex_lock(&fid->lock_mutex); |
| list_for_each_entry_safe(li, tmp, &fid->llist, llist) { |
| if (pfLock->fl_start <= li->offset && |
| (pfLock->fl_start + length) >= |
| (li->offset + li->length)) { |
| stored_rc = CIFSSMBLock(xid, tcon, |
| netfid, |
| li->length, li->offset, |
| 1, 0, li->type, false); |
| if (stored_rc) |
| rc = stored_rc; |
| else { |
| list_del(&li->llist); |
| kfree(li); |
| } |
| } |
| } |
| mutex_unlock(&fid->lock_mutex); |
| } |
| } |
| |
| if (pfLock->fl_flags & FL_POSIX) |
| posix_lock_file_wait(file, pfLock); |
| FreeXid(xid); |
| return rc; |
| } |
| |
| /* |
| * Set the timeout on write requests past EOF. For some servers (Windows) |
| * these calls can be very long. |
| * |
| * If we're writing >10M past the EOF we give a 180s timeout. Anything less |
| * than that gets a 45s timeout. Writes not past EOF get 15s timeouts. |
| * The 10M cutoff is totally arbitrary. A better scheme for this would be |
| * welcome if someone wants to suggest one. |
| * |
| * We may be able to do a better job with this if there were some way to |
| * declare that a file should be sparse. |
| */ |
| static int |
| cifs_write_timeout(struct cifsInodeInfo *cifsi, loff_t offset) |
| { |
| if (offset <= cifsi->server_eof) |
| return CIFS_STD_OP; |
| else if (offset > (cifsi->server_eof + (10 * 1024 * 1024))) |
| return CIFS_VLONG_OP; |
| else |
| return CIFS_LONG_OP; |
| } |
| |
| /* update the file size (if needed) after a write */ |
| static void |
| cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset, |
| unsigned int bytes_written) |
| { |
| loff_t end_of_write = offset + bytes_written; |
| |
| if (end_of_write > cifsi->server_eof) |
| cifsi->server_eof = end_of_write; |
| } |
| |
| 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; |
| struct cifsInodeInfo *cifsi = CIFS_I(file->f_path.dentry->d_inode); |
| |
| cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); |
| |
| /* cFYI(1, " write %d bytes to offset %lld of %s", write_size, |
| *poffset, file->f_path.dentry->d_name.name); */ |
| |
| if (file->private_data == NULL) |
| return -EBADF; |
| |
| open_file = file->private_data; |
| pTcon = tlink_tcon(open_file->tlink); |
| |
| rc = generic_write_checks(file, poffset, &write_size, 0); |
| if (rc) |
| return rc; |
| |
| xid = GetXid(); |
| |
| long_op = cifs_write_timeout(cifsi, *poffset); |
| 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) { |
| /* 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, 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 { |
| cifs_update_eof(cifsi, *poffset, bytes_written); |
| *poffset += bytes_written; |
| } |
| long_op = CIFS_STD_OP; /* subsequent writes fast - |
| 15 seconds is plenty */ |
| } |
| |
| cifs_stats_bytes_written(pTcon, total_written); |
| |
| /* since the write may have blocked check these pointers again */ |
| if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) { |
| struct inode *inode = file->f_path.dentry->d_inode; |
| /* Do not update local mtime - server will set its actual value on write |
| * inode->i_ctime = inode->i_mtime = |
| * current_fs_time(inode->i_sb);*/ |
| if (total_written > 0) { |
| spin_lock(&inode->i_lock); |
| if (*poffset > file->f_path.dentry->d_inode->i_size) |
| i_size_write(file->f_path.dentry->d_inode, |
| *poffset); |
| spin_unlock(&inode->i_lock); |
| } |
| mark_inode_dirty_sync(file->f_path.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; |
| struct cifsInodeInfo *cifsi = CIFS_I(file->f_path.dentry->d_inode); |
| |
| cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); |
| |
| cFYI(1, "write %zd bytes to offset %lld of %s", write_size, |
| *poffset, file->f_path.dentry->d_name.name); |
| |
| if (file->private_data == NULL) |
| return -EBADF; |
| open_file = file->private_data; |
| pTcon = tlink_tcon(open_file->tlink); |
| |
| xid = GetXid(); |
| |
| long_op = cifs_write_timeout(cifsi, *poffset); |
| 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) { |
| /* 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, false); |
| if (rc != 0) |
| break; |
| } |
| if (experimEnabled || (pTcon->ses->server && |
| ((pTcon->ses->server->secMode & |
| (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) |
| == 0))) { |
| struct kvec iov[2]; |
| unsigned int len; |
| |
| len = min((size_t)cifs_sb->wsize, |
| 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; |
| rc = CIFSSMBWrite2(xid, pTcon, |
| open_file->netfid, len, |
| *poffset, &bytes_written, |
| iov, 1, long_op); |
| } else |
| 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 { |
| cifs_update_eof(cifsi, *poffset, bytes_written); |
| *poffset += bytes_written; |
| } |
| long_op = CIFS_STD_OP; /* subsequent writes fast - |
| 15 seconds is plenty */ |
| } |
| |
| cifs_stats_bytes_written(pTcon, total_written); |
| |
| /* since the write may have blocked check these pointers again */ |
| if ((file->f_path.dentry) && (file->f_path.dentry->d_inode)) { |
| /*BB We could make this contingent on superblock ATIME flag too */ |
| /* file->f_path.dentry->d_inode->i_ctime = |
| file->f_path.dentry->d_inode->i_mtime = CURRENT_TIME;*/ |
| if (total_written > 0) { |
| spin_lock(&file->f_path.dentry->d_inode->i_lock); |
| if (*poffset > file->f_path.dentry->d_inode->i_size) |
| i_size_write(file->f_path.dentry->d_inode, |
| *poffset); |
| spin_unlock(&file->f_path.dentry->d_inode->i_lock); |
| } |
| mark_inode_dirty_sync(file->f_path.dentry->d_inode); |
| } |
| FreeXid(xid); |
| return total_written; |
| } |
| |
| #ifdef CONFIG_CIFS_EXPERIMENTAL |
| struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode, |
| bool fsuid_only) |
| { |
| struct cifsFileInfo *open_file = NULL; |
| struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb); |
| |
| /* only filter by fsuid on multiuser mounts */ |
| if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) |
| fsuid_only = false; |
| |
| read_lock(&GlobalSMBSeslock); |
| /* we could simply get the first_list_entry since write-only entries |
| are always at the end of the list but since the first entry might |
| have a close pending, we go through the whole list */ |
| list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { |
| if (open_file->closePend) |
| continue; |
| if (fsuid_only && open_file->uid != current_fsuid()) |
| continue; |
| if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) || |
| (open_file->pfile->f_flags & O_RDONLY))) { |
| if (!open_file->invalidHandle) { |
| /* found a good file */ |
| /* lock it so it will not be closed on us */ |
| cifsFileInfo_get(open_file); |
| read_unlock(&GlobalSMBSeslock); |
| return open_file; |
| } /* else might as well continue, and look for |
| another, or simply have the caller reopen it |
| again rather than trying to fix this handle */ |
| } else /* write only file */ |
| break; /* write only files are last so must be done */ |
| } |
| read_unlock(&GlobalSMBSeslock); |
| return NULL; |
| } |
| #endif |
| |
| struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode, |
| bool fsuid_only) |
| { |
| struct cifsFileInfo *open_file; |
| struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb); |
| bool any_available = false; |
| int rc; |
| |
| /* Having a null inode here (because mapping->host was set to zero by |
| the VFS or MM) should not happen but we had reports of on oops (due to |
| it being zero) during stress testcases so we need to check for it */ |
| |
| if (cifs_inode == NULL) { |
| cERROR(1, "Null inode passed to cifs_writeable_file"); |
| dump_stack(); |
| return NULL; |
| } |
| |
| /* only filter by fsuid on multiuser mounts */ |
| if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) |
| fsuid_only = false; |
| |
| read_lock(&GlobalSMBSeslock); |
| refind_writable: |
| list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { |
| if (open_file->closePend) |
| continue; |
| if (!any_available && open_file->pid != current->tgid) |
| continue; |
| if (fsuid_only && open_file->uid != current_fsuid()) |
| continue; |
| if (open_file->pfile && |
| ((open_file->pfile->f_flags & O_RDWR) || |
| (open_file->pfile->f_flags & O_WRONLY))) { |
| cifsFileInfo_get(open_file); |
| |
| if (!open_file->invalidHandle) { |
| /* found a good writable file */ |
| read_unlock(&GlobalSMBSeslock); |
| return open_file; |
| } |
| |
| read_unlock(&GlobalSMBSeslock); |
| /* Had to unlock since following call can block */ |
| rc = cifs_reopen_file(open_file->pfile, false); |
| if (!rc) { |
| if (!open_file->closePend) |
| return open_file; |
| else { /* start over in case this was deleted */ |
| /* since the list could be modified */ |
| read_lock(&GlobalSMBSeslock); |
| cifsFileInfo_put(open_file); |
| goto refind_writable; |
| } |
| } |
| |
| /* if it fails, try another handle if possible - |
| (we can not do this if closePending since |
| loop could be modified - in which case we |
| have to start at the beginning of the list |
| again. Note that it would be bad |
| to hold up writepages here (rather than |
| in caller) with continuous retries */ |
| cFYI(1, "wp failed on reopen file"); |
| read_lock(&GlobalSMBSeslock); |
| /* can not use this handle, no write |
| pending on this one after all */ |
| cifsFileInfo_put(open_file); |
| |
| if (open_file->closePend) /* list could have changed */ |
| goto refind_writable; |
| /* else we simply continue to the next entry. Thus |
| we do not loop on reopen errors. If we |
| can not reopen the file, for example if we |
| reconnected to a server with another client |
| racing to delete or lock the file we would not |
| make progress if we restarted before the beginning |
| of the loop here. */ |
| } |
| } |
| /* couldn't find useable FH with same pid, try any available */ |
| if (!any_available) { |
| any_available = true; |
| goto refind_writable; |
| } |
| read_unlock(&GlobalSMBSeslock); |
| return NULL; |
| } |
| |
| 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 inode *inode; |
| struct cifsFileInfo *open_file; |
| |
| if (!mapping || !mapping->host) |
| return -EFAULT; |
| |
| inode = page->mapping->host; |
| cifs_sb = CIFS_SB(inode->i_sb); |
| |
| 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); |
| |
| open_file = find_writable_file(CIFS_I(mapping->host), false); |
| if (open_file) { |
| bytes_written = cifs_write(open_file->pfile, write_data, |
| to-from, &offset); |
| cifsFileInfo_put(open_file); |
| /* 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) |
| rc = bytes_written; |
| } else { |
| cFYI(1, "No writeable filehandles for inode"); |
| rc = -EIO; |
| } |
| |
| kunmap(page); |
| return rc; |
| } |
| |
| static int cifs_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| 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; |
| pgoff_t index; |
| int range_whole = 0; |
| struct kvec *iov; |
| int len; |
| int n_iov = 0; |
| pgoff_t next; |
| int nr_pages; |
| __u64 offset = 0; |
| struct cifsFileInfo *open_file; |
| struct cifsTconInfo *tcon; |
| struct cifsInodeInfo *cifsi = CIFS_I(mapping->host); |
| struct page *page; |
| struct pagevec pvec; |
| int rc = 0; |
| int scanned = 0; |
| int xid, long_op; |
| |
| /* |
| * 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; |
| } |
| |
| 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); |
| |
| iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL); |
| if (iov == NULL) |
| return generic_writepages(mapping, wbc); |
| |
| /* |
| * if there's no open file, then this is likely to fail too, |
| * but it'll at least handle the return. Maybe it should be |
| * a BUG() instead? |
| */ |
| open_file = find_writable_file(CIFS_I(mapping->host), false); |
| if (!open_file) { |
| kfree(iov); |
| return generic_writepages(mapping, wbc); |
| } |
| |
| tcon = tlink_tcon(open_file->tlink); |
| if (!experimEnabled && tcon->ses->server->secMode & |
| (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) { |
| cifsFileInfo_put(open_file); |
| return generic_writepages(mapping, wbc); |
| } |
| cifsFileInfo_put(open_file); |
| |
| xid = GetXid(); |
| |
| pagevec_init(&pvec, 0); |
| if (wbc->range_cyclic) { |
| index = mapping->writeback_index; /* Start from prev offset */ |
| end = -1; |
| } else { |
| index = wbc->range_start >> PAGE_CACHE_SHIFT; |
| end = wbc->range_end >> PAGE_CACHE_SHIFT; |
| if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| range_whole = 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 (!trylock_page(page)) |
| break; |
| |
| if (unlikely(page->mapping != mapping)) { |
| unlock_page(page); |
| break; |
| } |
| |
| if (!wbc->range_cyclic && 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) || |
| !clear_page_dirty_for_io(page)) { |
| unlock_page(page); |
| break; |
| } |
| |
| /* |
| * This actually clears the dirty bit in the radix tree. |
| * See cifs_writepage() for more commentary. |
| */ |
| set_page_writeback(page); |
| |
| if (page_offset(page) >= mapping->host->i_size) { |
| done = 1; |
| unlock_page(page); |
| end_page_writeback(page); |
| break; |
| } |
| |
| /* |
| * BB can we get rid of this? pages are held by pvec |
| */ |
| page_cache_get(page); |
| |
| len = min(mapping->host->i_size - page_offset(page), |
| (loff_t)PAGE_CACHE_SIZE); |
| |
| /* reserve iov[0] for the smb header */ |
| n_iov++; |
| iov[n_iov].iov_base = kmap(page); |
| iov[n_iov].iov_len = len; |
| bytes_to_write += len; |
| |
| 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) { |
| open_file = find_writable_file(CIFS_I(mapping->host), |
| false); |
| if (!open_file) { |
| cERROR(1, "No writable handles for inode"); |
| rc = -EBADF; |
| } else { |
| long_op = cifs_write_timeout(cifsi, offset); |
| rc = CIFSSMBWrite2(xid, tcon, open_file->netfid, |
| bytes_to_write, offset, |
| &bytes_written, iov, n_iov, |
| long_op); |
| cifsFileInfo_put(open_file); |
| cifs_update_eof(cifsi, offset, bytes_written); |
| } |
| |
| if (rc || bytes_written < bytes_to_write) { |
| cERROR(1, "Write2 ret %d, wrote %d", |
| rc, bytes_written); |
| /* BB what if continued retry is |
| requested via mount flags? */ |
| if (rc == -ENOSPC) |
| set_bit(AS_ENOSPC, &mapping->flags); |
| else |
| set_bit(AS_EIO, &mapping->flags); |
| } else { |
| cifs_stats_bytes_written(tcon, bytes_written); |
| } |
| |
| for (i = 0; i < n_iov; i++) { |
| page = pvec.pages[first + i]; |
| /* 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); |
| kunmap(page); |
| unlock_page(page); |
| end_page_writeback(page); |
| page_cache_release(page); |
| } |
| if ((wbc->nr_to_write -= n_iov) <= 0) |
| done = 1; |
| index = next; |
| } else |
| /* Need to re-find the pages we skipped */ |
| index = pvec.pages[0]->index + 1; |
| |
| 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 (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) |
| mapping->writeback_index = index; |
| |
| FreeXid(xid); |
| kfree(iov); |
| 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"); |
| |
| /* |
| * Set the "writeback" flag, and clear "dirty" in the radix tree. |
| * |
| * A writepage() implementation always needs to do either this, |
| * or re-dirty the page with "redirty_page_for_writepage()" in |
| * the case of a failure. |
| * |
| * Just unlocking the page will cause the radix tree tag-bits |
| * to fail to update with the state of the page correctly. |
| */ |
| set_page_writeback(page); |
| rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE); |
| SetPageUptodate(page); /* BB add check for error and Clearuptodate? */ |
| unlock_page(page); |
| end_page_writeback(page); |
| page_cache_release(page); |
| FreeXid(xid); |
| return rc; |
| } |
| |
| static int cifs_write_end(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| int rc; |
| struct inode *inode = mapping->host; |
| |
| cFYI(1, "write_end for page %p from pos %lld with %d bytes", |
| page, pos, copied); |
| |
| if (PageChecked(page)) { |
| if (copied == len) |
| SetPageUptodate(page); |
| ClearPageChecked(page); |
| } else if (!PageUptodate(page) && copied == PAGE_CACHE_SIZE) |
| SetPageUptodate(page); |
| |
| if (!PageUptodate(page)) { |
| char *page_data; |
| unsigned offset = pos & (PAGE_CACHE_SIZE - 1); |
| int xid; |
| |
| xid = GetXid(); |
| /* 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, copied, &pos); |
| /* if (rc < 0) should we set writebehind rc? */ |
| kunmap(page); |
| |
| FreeXid(xid); |
| } else { |
| rc = copied; |
| pos += copied; |
| set_page_dirty(page); |
| } |
| |
| if (rc > 0) { |
| spin_lock(&inode->i_lock); |
| if (pos > inode->i_size) |
| i_size_write(inode, pos); |
| spin_unlock(&inode->i_lock); |
| } |
| |
| unlock_page(page); |
| page_cache_release(page); |
| |
| return rc; |
| } |
| |
| int cifs_fsync(struct file *file, int datasync) |
| { |
| int xid; |
| int rc = 0; |
| struct cifsTconInfo *tcon; |
| struct cifsFileInfo *smbfile = file->private_data; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| |
| xid = GetXid(); |
| |
| cFYI(1, "Sync file - name: %s datasync: 0x%x", |
| file->f_path.dentry->d_name.name, datasync); |
| |
| rc = filemap_write_and_wait(inode->i_mapping); |
| if (rc == 0) { |
| rc = CIFS_I(inode)->write_behind_rc; |
| CIFS_I(inode)->write_behind_rc = 0; |
| tcon = tlink_tcon(smbfile->tlink); |
| if (!rc && tcon && smbfile && |
| !(CIFS_SB(inode->i_sb)->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) |
| rc = CIFSSMBFlush(xid, tcon, smbfile->netfid); |
| } |
| |
| FreeXid(xid); |
| return rc; |
| } |
| |
| /* static void 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; */ |
| |
| /* 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 0 |
| if (rc < 0) |
| return rc; |
| return 0; |
| #endif |
| } */ |
| |
| /* |
| * As file closes, flush all cached write data for this inode checking |
| * for write behind errors. |
| */ |
| int cifs_flush(struct file *file, fl_owner_t id) |
| { |
| struct inode *inode = file->f_path.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); |
| /* reset wb rc if we were able to write out dirty pages */ |
| if (!rc) { |
| rc = CIFS_I(inode)->write_behind_rc; |
| 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_path.dentry->d_sb); |
| |
| if (file->private_data == NULL) { |
| rc = -EBADF; |
| FreeXid(xid); |
| return rc; |
| } |
| open_file = file->private_data; |
| pTcon = tlink_tcon(open_file->tlink); |
| |
| 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) { |
| int buf_type = CIFS_NO_BUFFER; |
| if ((open_file->invalidHandle) && |
| (!open_file->closePend)) { |
| rc = cifs_reopen_file(file, true); |
| if (rc != 0) |
| break; |
| } |
| rc = CIFSSMBRead(xid, pTcon, |
| open_file->netfid, |
| current_read_size, *poffset, |
| &bytes_read, &smb_read_data, |
| &buf_type); |
| pSMBr = (struct smb_com_read_rsp *)smb_read_data; |
| if (smb_read_data) { |
| if (copy_to_user(current_offset, |
| smb_read_data + |
| 4 /* RFC1001 length field */ + |
| le16_to_cpu(pSMBr->DataOffset), |
| bytes_read)) |
| rc = -EFAULT; |
| |
| 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); |
| smb_read_data = NULL; |
| } |
| } |
| if (rc || (bytes_read == 0)) { |
| if (total_read) { |
| break; |
| } else { |
| FreeXid(xid); |
| return rc; |
| } |
| } else { |
| cifs_stats_bytes_read(pTcon, bytes_read); |
| *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; |
| int buf_type = CIFS_NO_BUFFER; |
| |
| xid = GetXid(); |
| cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); |
| |
| if (file->private_data == NULL) { |
| rc = -EBADF; |
| FreeXid(xid); |
| return rc; |
| } |
| open_file = file->private_data; |
| pTcon = tlink_tcon(open_file->tlink); |
| |
| 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); |
| /* 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); |
| } |
| rc = -EAGAIN; |
| while (rc == -EAGAIN) { |
| if ((open_file->invalidHandle) && |
| (!open_file->closePend)) { |
| rc = cifs_reopen_file(file, true); |
| if (rc != 0) |
| break; |
| } |
| rc = CIFSSMBRead(xid, pTcon, |
| open_file->netfid, |
| current_read_size, *poffset, |
| &bytes_read, ¤t_offset, |
| &buf_type); |
| } |
| if (rc || (bytes_read == 0)) { |
| if (total_read) { |
| break; |
| } else { |
| FreeXid(xid); |
| return rc; |
| } |
| } else { |
| cifs_stats_bytes_read(pTcon, total_read); |
| *poffset += bytes_read; |
| } |
| } |
| FreeXid(xid); |
| return total_read; |
| } |
| |
| int cifs_file_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| int rc, xid; |
| |
| xid = GetXid(); |
| rc = cifs_revalidate_file(file); |
| 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 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_lru(page, mapping, page->index, |
| GFP_KERNEL)) { |
| page_cache_release(page); |
| cFYI(1, "Add page cache failed"); |
| data += PAGE_CACHE_SIZE; |
| bytes_read -= PAGE_CACHE_SIZE; |
| continue; |
| } |
| page_cache_release(page); |
| |
| 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); |
| data += PAGE_CACHE_SIZE; |
| |
| /* add page to FS-Cache */ |
| cifs_readpage_to_fscache(mapping->host, page); |
| } |
| 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; |
| unsigned int bytes_read = 0; |
| unsigned int read_size, i; |
| char *smb_read_data = NULL; |
| struct smb_com_read_rsp *pSMBr; |
| struct cifsFileInfo *open_file; |
| int buf_type = CIFS_NO_BUFFER; |
| |
| xid = GetXid(); |
| if (file->private_data == NULL) { |
| rc = -EBADF; |
| FreeXid(xid); |
| return rc; |
| } |
| open_file = file->private_data; |
| cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); |
| pTcon = tlink_tcon(open_file->tlink); |
| |
| /* |
| * Reads as many pages as possible from fscache. Returns -ENOBUFS |
| * immediately if the cookie is negative |
| */ |
| rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list, |
| &num_pages); |
| if (rc == 0) |
| goto read_complete; |
| |
| cFYI(DBG2, "rpages: num pages %d", num_pages); |
| 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); |
| cFYI(DBG2, "rpages: read size 0x%x contiguous pages %d", |
| read_size, contig_pages); |
| rc = -EAGAIN; |
| while (rc == -EAGAIN) { |
| if ((open_file->invalidHandle) && |
| (!open_file->closePend)) { |
| rc = cifs_reopen_file(file, true); |
| if (rc != 0) |
| break; |
| } |
| |
| rc = CIFSSMBRead(xid, pTcon, |
| open_file->netfid, |
| read_size, offset, |
| &bytes_read, &smb_read_data, |
| &buf_type); |
| /* BB more RC checks ? */ |
| if (rc == -EAGAIN) { |
| if (smb_read_data) { |
| 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); |
| smb_read_data = NULL; |
| } |
| } |
| } |
| if ((rc < 0) || (smb_read_data == NULL)) { |
| cFYI(1, "Read error in readpages: %d", rc); |
| break; |
| } else if (bytes_read > 0) { |
| task_io_account_read(bytes_read); |
| 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)); |
| |
| i += bytes_read >> PAGE_CACHE_SHIFT; |
| cifs_stats_bytes_read(pTcon, bytes_read); |
| if ((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 */ |
| |
| /* 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? */ |
| break; |
| } |
| if (smb_read_data) { |
| 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); |
| smb_read_data = NULL; |
| } |
| bytes_read = 0; |
| } |
| |
| /* need to free smb_read_data buf before exit */ |
| if (smb_read_data) { |
| 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); |
| smb_read_data = NULL; |
| } |
| |
| read_complete: |
| FreeXid(xid); |
| return rc; |
| } |
| |
| static int cifs_readpage_worker(struct file *file, struct page *page, |
| loff_t *poffset) |
| { |
| char *read_data; |
| int rc; |
| |
| /* Is the page cached? */ |
| rc = cifs_readpage_from_fscache(file->f_path.dentry->d_inode, page); |
| if (rc == 0) |
| goto read_complete; |
| |
| 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_path.dentry->d_inode->i_atime = |
| current_fs_time(file->f_path.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); |
| |
| /* send this page to the cache */ |
| cifs_readpage_to_fscache(file->f_path.dentry->d_inode, page); |
| |
| rc = 0; |
| |
| io_error: |
| kunmap(page); |
| page_cache_release(page); |
| |
| read_complete: |
| 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) { |
| rc = -EBADF; |
| FreeXid(xid); |
| return rc; |
| } |
| |
| 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; |
| } |
| |
| static int is_inode_writable(struct cifsInodeInfo *cifs_inode) |
| { |
| struct cifsFileInfo *open_file; |
| |
| 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))) { |
| read_unlock(&GlobalSMBSeslock); |
| return 1; |
| } |
| } |
| read_unlock(&GlobalSMBSeslock); |
| return 0; |
| } |
| |
| /* 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 */ |
| bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file) |
| { |
| if (!cifsInode) |
| return true; |
| |
| if (is_inode_writable(cifsInode)) { |
| /* This inode is open for write at least once */ |
| struct cifs_sb_info *cifs_sb; |
| |
| 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 true; |
| } |
| |
| if (i_size_read(&cifsInode->vfs_inode) < end_of_file) |
| return true; |
| |
| return false; |
| } else |
| return true; |
| } |
| |
| static int cifs_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
| loff_t offset = pos & (PAGE_CACHE_SIZE - 1); |
| loff_t page_start = pos & PAGE_MASK; |
| loff_t i_size; |
| struct page *page; |
| int rc = 0; |
| |
| cFYI(1, "write_begin from %lld len %d", (long long)pos, len); |
| |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) { |
| rc = -ENOMEM; |
| goto out; |
| } |
| |
| if (PageUptodate(page)) |
| goto out; |
| |
| /* |
| * If we write a full page it will be up to date, no need to read from |
| * the server. If the write is short, we'll end up doing a sync write |
| * instead. |
| */ |
| if (len == PAGE_CACHE_SIZE) |
| goto out; |
| |
| /* |
| * optimize away the read when we have an oplock, and we're not |
| * expecting to use any of the data we'd be reading in. That |
| * is, when the page lies beyond the EOF, or straddles the EOF |
| * and the write will cover all of the existing data. |
| */ |
| if (CIFS_I(mapping->host)->clientCanCacheRead) { |
| i_size = i_size_read(mapping->host); |
| if (page_start >= i_size || |
| (offset == 0 && (pos + len) >= i_size)) { |
| zero_user_segments(page, 0, offset, |
| offset + len, |
| PAGE_CACHE_SIZE); |
| /* |
| * PageChecked means that the parts of the page |
| * to which we're not writing are considered up |
| * to date. Once the data is copied to the |
| * page, it can be set uptodate. |
| */ |
| SetPageChecked(page); |
| goto out; |
| } |
| } |
| |
| if ((file->f_flags & O_ACCMODE) != O_WRONLY) { |
| /* |
| * might as well read a page, it is fast enough. If we get |
| * an error, we don't need to return it. cifs_write_end will |
| * do a sync write instead since PG_uptodate isn't set. |
| */ |
| cifs_readpage_worker(file, page, &page_start); |
| } else { |
| /* we could try using another file handle if there is one - |
| but how would we lock it to prevent close of that handle |
| racing with this read? In any case |
| this will be written out by write_end so is fine */ |
| } |
| out: |
| *pagep = page; |
| return rc; |
| } |
| |
| static int cifs_release_page(struct page *page, gfp_t gfp) |
| { |
| if (PagePrivate(page)) |
| return 0; |
| |
| return cifs_fscache_release_page(page, gfp); |
| } |
| |
| static void cifs_invalidate_page(struct page *page, unsigned long offset) |
| { |
| struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host); |
| |
| if (offset == 0) |
| cifs_fscache_invalidate_page(page, &cifsi->vfs_inode); |
| } |
| |
| void cifs_oplock_break(struct work_struct *work) |
| { |
| struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo, |
| oplock_break); |
| struct inode *inode = cfile->pInode; |
| struct cifsInodeInfo *cinode = CIFS_I(inode); |
| int rc, waitrc = 0; |
| |
| if (inode && S_ISREG(inode->i_mode)) { |
| if (cinode->clientCanCacheRead) |
| break_lease(inode, O_RDONLY); |
| else |
| break_lease(inode, O_WRONLY); |
| rc = filemap_fdatawrite(inode->i_mapping); |
| if (cinode->clientCanCacheRead == 0) { |
| waitrc = filemap_fdatawait(inode->i_mapping); |
| invalidate_remote_inode(inode); |
| } |
| if (!rc) |
| rc = waitrc; |
| if (rc) |
| cinode->write_behind_rc = rc; |
| cFYI(1, "Oplock flush inode %p rc %d", inode, rc); |
| } |
| |
| /* |
| * releasing stale oplock after recent reconnect of smb session using |
| * a now incorrect file handle is not a data integrity issue but do |
| * not bother sending an oplock release if session to server still is |
| * disconnected since oplock already released by the server |
| */ |
| if (!cfile->closePend && !cfile->oplock_break_cancelled) { |
| rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, 0, |
| 0, 0, 0, LOCKING_ANDX_OPLOCK_RELEASE, false); |
| cFYI(1, "Oplock release rc = %d", rc); |
| } |
| |
| /* |
| * We might have kicked in before is_valid_oplock_break() |
| * finished grabbing reference for us. Make sure it's done by |
| * waiting for GlobalSMSSeslock. |
| */ |
| write_lock(&GlobalSMBSeslock); |
| write_unlock(&GlobalSMBSeslock); |
| |
| cifs_oplock_break_put(cfile); |
| } |
| |
| void cifs_oplock_break_get(struct cifsFileInfo *cfile) |
| { |
| mntget(cfile->mnt); |
| cifsFileInfo_get(cfile); |
| } |
| |
| void cifs_oplock_break_put(struct cifsFileInfo *cfile) |
| { |
| mntput(cfile->mnt); |
| cifsFileInfo_put(cfile); |
| } |
| |
| const struct address_space_operations cifs_addr_ops = { |
| .readpage = cifs_readpage, |
| .readpages = cifs_readpages, |
| .writepage = cifs_writepage, |
| .writepages = cifs_writepages, |
| .write_begin = cifs_write_begin, |
| .write_end = cifs_write_end, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .releasepage = cifs_release_page, |
| .invalidatepage = cifs_invalidate_page, |
| /* .sync_page = cifs_sync_page, */ |
| /* .direct_IO = */ |
| }; |
| |
| /* |
| * cifs_readpages requires the server to support a buffer large enough to |
| * contain the header plus one complete page of data. Otherwise, we need |
| * to leave cifs_readpages out of the address space operations. |
| */ |
| const struct address_space_operations cifs_addr_ops_smallbuf = { |
| .readpage = cifs_readpage, |
| .writepage = cifs_writepage, |
| .writepages = cifs_writepages, |
| .write_begin = cifs_write_begin, |
| .write_end = cifs_write_end, |
| .set_page_dirty = __set_page_dirty_nobuffers, |
| .releasepage = cifs_release_page, |
| .invalidatepage = cifs_invalidate_page, |
| /* .sync_page = cifs_sync_page, */ |
| /* .direct_IO = */ |
| }; |