diff options
Diffstat (limited to 'fs/cifs/file.c')
| -rw-r--r-- | fs/cifs/file.c | 3060 |
1 files changed, 3060 insertions, 0 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c new file mode 100644 index 00000000..e7ebb5a2 --- /dev/null +++ b/fs/cifs/file.c @@ -0,0 +1,3060 @@ +/* + * 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 <linux/swap.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 u32 cifs_posix_convert_flags(unsigned int flags) +{ + u32 posix_flags = 0; + + if ((flags & O_ACCMODE) == O_RDONLY) + posix_flags = SMB_O_RDONLY; + else if ((flags & O_ACCMODE) == O_WRONLY) + posix_flags = SMB_O_WRONLY; + else if ((flags & O_ACCMODE) == O_RDWR) + posix_flags = SMB_O_RDWR; + + if (flags & O_CREAT) + posix_flags |= SMB_O_CREAT; + if (flags & O_EXCL) + posix_flags |= SMB_O_EXCL; + if (flags & O_TRUNC) + posix_flags |= SMB_O_TRUNC; + /* be safe and imply O_SYNC for O_DSYNC */ + if (flags & O_DSYNC) + posix_flags |= SMB_O_SYNC; + if (flags & O_DIRECTORY) + posix_flags |= SMB_O_DIRECTORY; + if (flags & O_NOFOLLOW) + posix_flags |= SMB_O_NOFOLLOW; + if (flags & O_DIRECT) + posix_flags |= SMB_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; +} + +int cifs_posix_open(char *full_path, struct inode **pinode, + struct super_block *sb, int mode, unsigned int f_flags, + __u32 *poplock, __u16 *pnetfid, int xid) +{ + int rc; + FILE_UNIX_BASIC_INFO *presp_data; + __u32 posix_flags = 0; + struct cifs_sb_info *cifs_sb = CIFS_SB(sb); + struct cifs_fattr fattr; + struct tcon_link *tlink; + struct cifs_tcon *tcon; + + cFYI(1, "posix open %s", full_path); + + presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL); + if (presp_data == NULL) + return -ENOMEM; + + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + goto posix_open_ret; + } + + tcon = tlink_tcon(tlink); + mode &= ~current_umask(); + + posix_flags = cifs_posix_convert_flags(f_flags); + rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data, + poplock, full_path, cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & + CIFS_MOUNT_MAP_SPECIAL_CHR); + cifs_put_tlink(tlink); + + if (rc) + goto posix_open_ret; + + if (presp_data->Type == cpu_to_le32(-1)) + goto posix_open_ret; /* open ok, caller does qpathinfo */ + + if (!pinode) + goto posix_open_ret; /* caller does not need info */ + + cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb); + + /* get new inode and set it up */ + if (*pinode == NULL) { + cifs_fill_uniqueid(sb, &fattr); + *pinode = cifs_iget(sb, &fattr); + if (!*pinode) { + rc = -ENOMEM; + goto posix_open_ret; + } + } else { + cifs_fattr_to_inode(*pinode, &fattr); + } + +posix_open_ret: + kfree(presp_data); + return rc; +} + +static int +cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb, + struct cifs_tcon *tcon, unsigned int f_flags, __u32 *poplock, + __u16 *pnetfid, int xid) +{ + int rc; + int desiredAccess; + int disposition; + int create_options = CREATE_NOT_DIR; + FILE_ALL_INFO *buf; + + desiredAccess = cifs_convert_flags(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(f_flags); + + /* BB pass O_SYNC flag through on file attributes .. BB */ + + buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + if (tcon->ses->capabilities & CAP_NT_SMBS) + rc = CIFSSMBOpen(xid, tcon, full_path, disposition, + desiredAccess, create_options, pnetfid, poplock, buf, + cifs_sb->local_nls, cifs_sb->mnt_cifs_flags + & CIFS_MOUNT_MAP_SPECIAL_CHR); + else + rc = SMBLegacyOpen(xid, tcon, full_path, disposition, + desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf, + cifs_sb->local_nls, cifs_sb->mnt_cifs_flags + & CIFS_MOUNT_MAP_SPECIAL_CHR); + + if (rc) + goto out; + + 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, buf, inode->i_sb, + xid, pnetfid); + +out: + kfree(buf); + return rc; +} + +struct cifsFileInfo * +cifs_new_fileinfo(__u16 fileHandle, struct file *file, + struct tcon_link *tlink, __u32 oplock) +{ + struct dentry *dentry = file->f_path.dentry; + struct inode *inode = dentry->d_inode; + struct cifsInodeInfo *pCifsInode = CIFS_I(inode); + struct cifsFileInfo *pCifsFile; + + pCifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL); + if (pCifsFile == NULL) + return pCifsFile; + + pCifsFile->count = 1; + pCifsFile->netfid = fileHandle; + pCifsFile->pid = current->tgid; + pCifsFile->uid = current_fsuid(); + pCifsFile->dentry = dget(dentry); + pCifsFile->f_flags = file->f_flags; + pCifsFile->invalidHandle = false; + pCifsFile->tlink = cifs_get_tlink(tlink); + mutex_init(&pCifsFile->fh_mutex); + INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break); + + spin_lock(&cifs_file_list_lock); + list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList)); + /* if readable file instance put first in list*/ + if (file->f_mode & FMODE_READ) + list_add(&pCifsFile->flist, &pCifsInode->openFileList); + else + list_add_tail(&pCifsFile->flist, &pCifsInode->openFileList); + spin_unlock(&cifs_file_list_lock); + + cifs_set_oplock_level(pCifsInode, oplock); + pCifsInode->can_cache_brlcks = pCifsInode->clientCanCacheAll; + + file->private_data = pCifsFile; + return pCifsFile; +} + +static void cifs_del_lock_waiters(struct cifsLockInfo *lock); + +/* + * Release a reference on the file private data. This may involve closing + * the filehandle out on the server. Must be called without holding + * cifs_file_list_lock. + */ +void cifsFileInfo_put(struct cifsFileInfo *cifs_file) +{ + struct inode *inode = cifs_file->dentry->d_inode; + struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink); + struct cifsInodeInfo *cifsi = CIFS_I(inode); + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct cifsLockInfo *li, *tmp; + + spin_lock(&cifs_file_list_lock); + if (--cifs_file->count > 0) { + spin_unlock(&cifs_file_list_lock); + return; + } + + /* remove it from the lists */ + list_del(&cifs_file->flist); + list_del(&cifs_file->tlist); + + if (list_empty(&cifsi->openFileList)) { + cFYI(1, "closing last open instance for inode %p", + cifs_file->dentry->d_inode); + + /* in strict cache mode we need invalidate mapping on the last + close because it may cause a error when we open this file + again and get at least level II oplock */ + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) + CIFS_I(inode)->invalid_mapping = true; + + cifs_set_oplock_level(cifsi, 0); + } + spin_unlock(&cifs_file_list_lock); + + cancel_work_sync(&cifs_file->oplock_break); + + if (!tcon->need_reconnect && !cifs_file->invalidHandle) { + int xid, rc; + + xid = GetXid(); + rc = CIFSSMBClose(xid, tcon, cifs_file->netfid); + FreeXid(xid); + } + + /* Delete any outstanding lock records. We'll lose them when the file + * is closed anyway. + */ + mutex_lock(&cifsi->lock_mutex); + list_for_each_entry_safe(li, tmp, &cifsi->llist, llist) { + if (li->netfid != cifs_file->netfid) + continue; + list_del(&li->llist); + cifs_del_lock_waiters(li); + kfree(li); + } + mutex_unlock(&cifsi->lock_mutex); + + cifs_put_tlink(cifs_file->tlink); + dput(cifs_file->dentry); + kfree(cifs_file); +} + +int cifs_open(struct inode *inode, struct file *file) +{ + int rc = -EACCES; + int xid; + __u32 oplock; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *tcon; + struct tcon_link *tlink; + struct cifsFileInfo *pCifsFile = NULL; + char *full_path = NULL; + bool posix_open_ok = false; + __u16 netfid; + + 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); + + 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 (tcon->ses->server->oplocks) + 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))) { + /* 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 */, + file->f_flags, &oplock, &netfid, xid); + if (rc == 0) { + cFYI(1, "posix open succeeded"); + posix_open_ok = true; + } 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 */ + } + + if (!posix_open_ok) { + rc = cifs_nt_open(full_path, inode, cifs_sb, tcon, + file->f_flags, &oplock, &netfid, xid); + if (rc) + goto out; + } + + pCifsFile = cifs_new_fileinfo(netfid, file, tlink, oplock); + if (pCifsFile == NULL) { + CIFSSMBClose(xid, tcon, netfid); + rc = -ENOMEM; + goto out; + } + + cifs_fscache_set_inode_cookie(inode, file); + + if ((oplock & CIFS_CREATE_ACTION) && !posix_open_ok && tcon->unix_ext) { + /* time to set mode which we can not set earlier due to + problems creating new read-only files */ + 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, + }; + CIFSSMBUnixSetFileInfo(xid, tcon, &args, netfid, + pCifsFile->pid); + } + +out: + 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 cifsFileInfo *pCifsFile, bool can_flush) +{ + int rc = -EACCES; + int xid; + __u32 oplock; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *tcon; + struct cifsInodeInfo *pCifsInode; + struct inode *inode; + char *full_path = NULL; + int desiredAccess; + int disposition = FILE_OPEN; + int create_options = CREATE_NOT_DIR; + __u16 netfid; + + xid = GetXid(); + mutex_lock(&pCifsFile->fh_mutex); + if (!pCifsFile->invalidHandle) { + mutex_unlock(&pCifsFile->fh_mutex); + rc = 0; + FreeXid(xid); + return rc; + } + + inode = pCifsFile->dentry->d_inode; + 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(pCifsFile->dentry); + if (full_path == NULL) { + rc = -ENOMEM; + mutex_unlock(&pCifsFile->fh_mutex); + FreeXid(xid); + return rc; + } + + cFYI(1, "inode = 0x%p file flags 0x%x for %s", + inode, pCifsFile->f_flags, full_path); + + if (tcon->ses->server->oplocks) + 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))) { + + /* + * O_CREAT, O_EXCL and O_TRUNC already had their effect on the + * original open. Must mask them off for a reopen. + */ + unsigned int oflags = pCifsFile->f_flags & + ~(O_CREAT | O_EXCL | O_TRUNC); + + 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(pCifsFile->f_flags); + + if (backup_cred(cifs_sb)) + create_options |= CREATE_OPEN_BACKUP_INTENT; + + /* 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_options, &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); + goto reopen_error_exit; + } + +reopen_success: + pCifsFile->netfid = netfid; + pCifsFile->invalidHandle = false; + mutex_unlock(&pCifsFile->fh_mutex); + pCifsInode = CIFS_I(inode); + + if (can_flush) { + rc = filemap_write_and_wait(inode->i_mapping); + mapping_set_error(inode->i_mapping, rc); + + 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 */ + + cifs_set_oplock_level(pCifsInode, oplock); + + cifs_relock_file(pCifsFile); + +reopen_error_exit: + kfree(full_path); + FreeXid(xid); + return rc; +} + +int cifs_close(struct inode *inode, struct file *file) +{ + if (file->private_data != NULL) { + cifsFileInfo_put(file->private_data); + file->private_data = NULL; + } + + /* return code from the ->release op is always ignored */ + return 0; +} + +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 cifs_tcon *pTcon = tlink_tcon(pCFileStruct->tlink); + + cFYI(1, "Freeing private data in close dir"); + spin_lock(&cifs_file_list_lock); + if (!pCFileStruct->srch_inf.endOfSearch && + !pCFileStruct->invalidHandle) { + pCFileStruct->invalidHandle = true; + spin_unlock(&cifs_file_list_lock); + 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 + spin_unlock(&cifs_file_list_lock); + 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 struct cifsLockInfo * +cifs_lock_init(__u64 offset, __u64 length, __u8 type, __u16 netfid) +{ + struct cifsLockInfo *lock = + kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL); + if (!lock) + return lock; + lock->offset = offset; + lock->length = length; + lock->type = type; + lock->netfid = netfid; + lock->pid = current->tgid; + INIT_LIST_HEAD(&lock->blist); + init_waitqueue_head(&lock->block_q); + return lock; +} + +static void +cifs_del_lock_waiters(struct cifsLockInfo *lock) +{ + struct cifsLockInfo *li, *tmp; + list_for_each_entry_safe(li, tmp, &lock->blist, blist) { + list_del_init(&li->blist); + wake_up(&li->block_q); + } +} + +static bool +__cifs_find_lock_conflict(struct cifsInodeInfo *cinode, __u64 offset, + __u64 length, __u8 type, __u16 netfid, + struct cifsLockInfo **conf_lock) +{ + struct cifsLockInfo *li, *tmp; + + list_for_each_entry_safe(li, tmp, &cinode->llist, llist) { + if (offset + length <= li->offset || + offset >= li->offset + li->length) + continue; + else if ((type & LOCKING_ANDX_SHARED_LOCK) && + ((netfid == li->netfid && current->tgid == li->pid) || + type == li->type)) + continue; + else { + *conf_lock = li; + return true; + } + } + return false; +} + +static bool +cifs_find_lock_conflict(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock, + struct cifsLockInfo **conf_lock) +{ + return __cifs_find_lock_conflict(cinode, lock->offset, lock->length, + lock->type, lock->netfid, conf_lock); +} + +/* + * Check if there is another lock that prevents us to set the lock (mandatory + * style). If such a lock exists, update the flock structure with its + * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks + * or leave it the same if we can't. Returns 0 if we don't need to request to + * the server or 1 otherwise. + */ +static int +cifs_lock_test(struct cifsInodeInfo *cinode, __u64 offset, __u64 length, + __u8 type, __u16 netfid, struct file_lock *flock) +{ + int rc = 0; + struct cifsLockInfo *conf_lock; + bool exist; + + mutex_lock(&cinode->lock_mutex); + + exist = __cifs_find_lock_conflict(cinode, offset, length, type, netfid, + &conf_lock); + if (exist) { + flock->fl_start = conf_lock->offset; + flock->fl_end = conf_lock->offset + conf_lock->length - 1; + flock->fl_pid = conf_lock->pid; + if (conf_lock->type & LOCKING_ANDX_SHARED_LOCK) + flock->fl_type = F_RDLCK; + else + flock->fl_type = F_WRLCK; + } else if (!cinode->can_cache_brlcks) + rc = 1; + else + flock->fl_type = F_UNLCK; + + mutex_unlock(&cinode->lock_mutex); + return rc; +} + +static void +cifs_lock_add(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock) +{ + mutex_lock(&cinode->lock_mutex); + list_add_tail(&lock->llist, &cinode->llist); + mutex_unlock(&cinode->lock_mutex); +} + +/* + * Set the byte-range lock (mandatory style). Returns: + * 1) 0, if we set the lock and don't need to request to the server; + * 2) 1, if no locks prevent us but we need to request to the server; + * 3) -EACCESS, if there is a lock that prevents us and wait is false. + */ +static int +cifs_lock_add_if(struct cifsInodeInfo *cinode, struct cifsLockInfo *lock, + bool wait) +{ + struct cifsLockInfo *conf_lock; + bool exist; + int rc = 0; + +try_again: + exist = false; + mutex_lock(&cinode->lock_mutex); + + exist = cifs_find_lock_conflict(cinode, lock, &conf_lock); + if (!exist && cinode->can_cache_brlcks) { + list_add_tail(&lock->llist, &cinode->llist); + mutex_unlock(&cinode->lock_mutex); + return rc; + } + + if (!exist) + rc = 1; + else if (!wait) + rc = -EACCES; + else { + list_add_tail(&lock->blist, &conf_lock->blist); + mutex_unlock(&cinode->lock_mutex); + rc = wait_event_interruptible(lock->block_q, + (lock->blist.prev == &lock->blist) && + (lock->blist.next == &lock->blist)); + if (!rc) + goto try_again; + mutex_lock(&cinode->lock_mutex); + list_del_init(&lock->blist); + } + + mutex_unlock(&cinode->lock_mutex); + return rc; +} + +/* + * Check if there is another lock that prevents us to set the lock (posix + * style). If such a lock exists, update the flock structure with its + * properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks + * or leave it the same if we can't. Returns 0 if we don't need to request to + * the server or 1 otherwise. + */ +static int +cifs_posix_lock_test(struct file *file, struct file_lock *flock) +{ + int rc = 0; + struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode); + unsigned char saved_type = flock->fl_type; + + if ((flock->fl_flags & FL_POSIX) == 0) + return 1; + + mutex_lock(&cinode->lock_mutex); + posix_test_lock(file, flock); + + if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) { + flock->fl_type = saved_type; + rc = 1; + } + + mutex_unlock(&cinode->lock_mutex); + return rc; +} + +/* + * Set the byte-range lock (posix style). Returns: + * 1) 0, if we set the lock and don't need to request to the server; + * 2) 1, if we need to request to the server; + * 3) <0, if the error occurs while setting the lock. + */ +static int +cifs_posix_lock_set(struct file *file, struct file_lock *flock) +{ + struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode); + int rc = 1; + + if ((flock->fl_flags & FL_POSIX) == 0) + return rc; + +try_again: + mutex_lock(&cinode->lock_mutex); + if (!cinode->can_cache_brlcks) { + mutex_unlock(&cinode->lock_mutex); + return rc; + } + + rc = posix_lock_file(file, flock, NULL); + mutex_unlock(&cinode->lock_mutex); + if (rc == FILE_LOCK_DEFERRED) { + rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next); + if (!rc) + goto try_again; + locks_delete_block(flock); + } + return rc; +} + +static int +cifs_push_mandatory_locks(struct cifsFileInfo *cfile) +{ + int xid, rc = 0, stored_rc; + struct cifsLockInfo *li, *tmp; + struct cifs_tcon *tcon; + struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode); + unsigned int num, max_num; + LOCKING_ANDX_RANGE *buf, *cur; + int types[] = {LOCKING_ANDX_LARGE_FILES, + LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES}; + int i; + + xid = GetXid(); + tcon = tlink_tcon(cfile->tlink); + + mutex_lock(&cinode->lock_mutex); + if (!cinode->can_cache_brlcks) { + mutex_unlock(&cinode->lock_mutex); + FreeXid(xid); + return rc; + } + + max_num = (tcon->ses->server->maxBuf - sizeof(struct smb_hdr)) / + sizeof(LOCKING_ANDX_RANGE); + buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); + if (!buf) { + mutex_unlock(&cinode->lock_mutex); + FreeXid(xid); + return rc; + } + + for (i = 0; i < 2; i++) { + cur = buf; + num = 0; + list_for_each_entry_safe(li, tmp, &cinode->llist, llist) { + if (li->type != types[i]) + continue; + cur->Pid = cpu_to_le16(li->pid); + cur->LengthLow = cpu_to_le32((u32)li->length); + cur->LengthHigh = cpu_to_le32((u32)(li->length>>32)); + cur->OffsetLow = cpu_to_le32((u32)li->offset); + cur->OffsetHigh = cpu_to_le32((u32)(li->offset>>32)); + if (++num == max_num) { + stored_rc = cifs_lockv(xid, tcon, cfile->netfid, + li->type, 0, num, buf); + if (stored_rc) + rc = stored_rc; + cur = buf; + num = 0; + } else + cur++; + } + + if (num) { + stored_rc = cifs_lockv(xid, tcon, cfile->netfid, + types[i], 0, num, buf); + if (stored_rc) + rc = stored_rc; + } + } + + cinode->can_cache_brlcks = false; + mutex_unlock(&cinode->lock_mutex); + + kfree(buf); + FreeXid(xid); + return rc; +} + +/* copied from fs/locks.c with a name change */ +#define cifs_for_each_lock(inode, lockp) \ + for (lockp = &inode->i_flock; *lockp != NULL; \ + lockp = &(*lockp)->fl_next) + +struct lock_to_push { + struct list_head llist; + __u64 offset; + __u64 length; + __u32 pid; + __u16 netfid; + __u8 type; +}; + +static int +cifs_push_posix_locks(struct cifsFileInfo *cfile) +{ + struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode); + struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); + struct file_lock *flock, **before; + unsigned int count = 0, i = 0; + int rc = 0, xid, type; + struct list_head locks_to_send, *el; + struct lock_to_push *lck, *tmp; + __u64 length; + + xid = GetXid(); + + mutex_lock(&cinode->lock_mutex); + if (!cinode->can_cache_brlcks) { + mutex_unlock(&cinode->lock_mutex); + FreeXid(xid); + return rc; + } + + lock_flocks(); + cifs_for_each_lock(cfile->dentry->d_inode, before) { + if ((*before)->fl_flags & FL_POSIX) + count++; + } + unlock_flocks(); + + INIT_LIST_HEAD(&locks_to_send); + + /* + * Allocating count locks is enough because no FL_POSIX locks can be + * added to the list while we are holding cinode->lock_mutex that + * protects locking operations of this inode. + */ + for (; i < count; i++) { + lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL); + if (!lck) { + rc = -ENOMEM; + goto err_out; + } + list_add_tail(&lck->llist, &locks_to_send); + } + + el = locks_to_send.next; + lock_flocks(); + cifs_for_each_lock(cfile->dentry->d_inode, before) { + flock = *before; + if ((flock->fl_flags & FL_POSIX) == 0) + continue; + if (el == &locks_to_send) { + /* + * The list ended. We don't have enough allocated + * structures - something is really wrong. + */ + cERROR(1, "Can't push all brlocks!"); + break; + } + length = 1 + flock->fl_end - flock->fl_start; + if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK) + type = CIFS_RDLCK; + else + type = CIFS_WRLCK; + lck = list_entry(el, struct lock_to_push, llist); + lck->pid = flock->fl_pid; + lck->netfid = cfile->netfid; + lck->length = length; + lck->type = type; + lck->offset = flock->fl_start; + el = el->next; + } + unlock_flocks(); + + list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) { + struct file_lock tmp_lock; + int stored_rc; + + tmp_lock.fl_start = lck->offset; + stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid, + 0, lck->length, &tmp_lock, + lck->type, 0); + if (stored_rc) + rc = stored_rc; + list_del(&lck->llist); + kfree(lck); + } + +out: + cinode->can_cache_brlcks = false; + mutex_unlock(&cinode->lock_mutex); + + FreeXid(xid); + return rc; +err_out: + list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) { + list_del(&lck->llist); + kfree(lck); + } + goto out; +} + +static int +cifs_push_locks(struct cifsFileInfo *cfile) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb); + struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); + + 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)) + return cifs_push_posix_locks(cfile); + + return cifs_push_mandatory_locks(cfile); +} + +static void +cifs_read_flock(struct file_lock *flock, __u8 *type, int *lock, int *unlock, + bool *wait_flag) +{ + if (flock->fl_flags & FL_POSIX) + cFYI(1, "Posix"); + if (flock->fl_flags & FL_FLOCK) + cFYI(1, "Flock"); + if (flock->fl_flags & FL_SLEEP) { + cFYI(1, "Blocking lock"); + *wait_flag = true; + } + if (flock->fl_flags & FL_ACCESS) + cFYI(1, "Process suspended by mandatory locking - " + "not implemented yet"); + if (flock->fl_flags & FL_LEASE) + cFYI(1, "Lease on file - not implemented yet"); + if (flock->fl_flags & + (~(FL_POSIX | FL_FLOCK | FL_SLEEP | FL_ACCESS | FL_LEASE))) + cFYI(1, "Unknown lock flags 0x%x", flock->fl_flags); + + *type = LOCKING_ANDX_LARGE_FILES; + if (flock->fl_type == F_WRLCK) { + cFYI(1, "F_WRLCK "); + *lock = 1; + } else if (flock->fl_type == F_UNLCK) { + cFYI(1, "F_UNLCK"); + *unlock = 1; + /* Check if unlock includes more than one lock range */ + } else if (flock->fl_type == F_RDLCK) { + cFYI(1, "F_RDLCK"); + *type |= LOCKING_ANDX_SHARED_LOCK; + *lock = 1; + } else if (flock->fl_type == F_EXLCK) { + cFYI(1, "F_EXLCK"); + *lock = 1; + } else if (flock->fl_type == F_SHLCK) { + cFYI(1, "F_SHLCK"); + *type |= LOCKING_ANDX_SHARED_LOCK; + *lock = 1; + } else + cFYI(1, "Unknown type of lock"); +} + +static int +cifs_getlk(struct file *file, struct file_lock *flock, __u8 type, + bool wait_flag, bool posix_lck, int xid) +{ + int rc = 0; + __u64 length = 1 + flock->fl_end - flock->fl_start; + struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data; + struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); + struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode); + __u16 netfid = cfile->netfid; + + if (posix_lck) { + int posix_lock_type; + + rc = cifs_posix_lock_test(file, flock); + if (!rc) + return rc; + + if (type & LOCKING_ANDX_SHARED_LOCK) + posix_lock_type = CIFS_RDLCK; + else + posix_lock_type = CIFS_WRLCK; + rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid, + 1 /* get */, length, flock, + posix_lock_type, wait_flag); + return rc; + } + + rc = cifs_lock_test(cinode, flock->fl_start, length, type, netfid, + flock); + if (!rc) + return rc; + + /* BB we could chain these into one lock request BB */ + rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, length, + flock->fl_start, 0, 1, type, 0, 0); + if (rc == 0) { + rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, + length, flock->fl_start, 1, 0, + type, 0, 0); + flock->fl_type = F_UNLCK; + if (rc != 0) + cERROR(1, "Error unlocking previously locked " + "range %d during test of lock", rc); + return 0; + } + + if (type & LOCKING_ANDX_SHARED_LOCK) { + flock->fl_type = F_WRLCK; + return 0; + } + + rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, length, + flock->fl_start, 0, 1, + type | LOCKING_ANDX_SHARED_LOCK, 0, 0); + if (rc == 0) { + rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, + length, flock->fl_start, 1, 0, + type | LOCKING_ANDX_SHARED_LOCK, + 0, 0); + flock->fl_type = F_RDLCK; + if (rc != 0) + cERROR(1, "Error unlocking previously locked " + "range %d during test of lock", rc); + } else + flock->fl_type = F_WRLCK; + + return 0; +} + +static void +cifs_move_llist(struct list_head *source, struct list_head *dest) +{ + struct list_head *li, *tmp; + list_for_each_safe(li, tmp, source) + list_move(li, dest); +} + +static void +cifs_free_llist(struct list_head *llist) +{ + struct cifsLockInfo *li, *tmp; + list_for_each_entry_safe(li, tmp, llist, llist) { + cifs_del_lock_waiters(li); + list_del(&li->llist); + kfree(li); + } +} + +static int +cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, int xid) +{ + int rc = 0, stored_rc; + int types[] = {LOCKING_ANDX_LARGE_FILES, + LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES}; + unsigned int i; + unsigned int max_num, num; + LOCKING_ANDX_RANGE *buf, *cur; + struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); + struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode); + struct cifsLockInfo *li, *tmp; + __u64 length = 1 + flock->fl_end - flock->fl_start; + struct list_head tmp_llist; + + INIT_LIST_HEAD(&tmp_llist); + + max_num = (tcon->ses->server->maxBuf - sizeof(struct smb_hdr)) / + sizeof(LOCKING_ANDX_RANGE); + buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + mutex_lock(&cinode->lock_mutex); + for (i = 0; i < 2; i++) { + cur = buf; + num = 0; + list_for_each_entry_safe(li, tmp, &cinode->llist, llist) { + if (flock->fl_start > li->offset || + (flock->fl_start + length) < + (li->offset + li->length)) + continue; + if (current->tgid != li->pid) + continue; + if (cfile->netfid != li->netfid) + continue; + if (types[i] != li->type) + continue; + if (!cinode->can_cache_brlcks) { + cur->Pid = cpu_to_le16(li->pid); + cur->LengthLow = cpu_to_le32((u32)li->length); + cur->LengthHigh = + cpu_to_le32((u32)(li->length>>32)); + cur->OffsetLow = cpu_to_le32((u32)li->offset); + cur->OffsetHigh = + cpu_to_le32((u32)(li->offset>>32)); + /* + * We need to save a lock here to let us add + * it again to the inode list if the unlock + * range request fails on the server. + */ + list_move(&li->llist, &tmp_llist); + if (++num == max_num) { + stored_rc = cifs_lockv(xid, tcon, + cfile->netfid, + li->type, num, + 0, buf); + if (stored_rc) { + /* + * We failed on the unlock range + * request - add all locks from + * the tmp list to the head of + * the inode list. + */ + cifs_move_llist(&tmp_llist, + &cinode->llist); + rc = stored_rc; + } else + /* + * The unlock range request + * succeed - free the tmp list. + */ + cifs_free_llist(&tmp_llist); + cur = buf; + num = 0; + } else + cur++; + } else { + /* + * We can cache brlock requests - simply remove + * a lock from the inode list. + */ + list_del(&li->llist); + cifs_del_lock_waiters(li); + kfree(li); + } + } + if (num) { + stored_rc = cifs_lockv(xid, tcon, cfile->netfid, + types[i], num, 0, buf); + if (stored_rc) { + cifs_move_llist(&tmp_llist, &cinode->llist); + rc = stored_rc; + } else + cifs_free_llist(&tmp_llist); + } + } + + mutex_unlock(&cinode->lock_mutex); + kfree(buf); + return rc; +} + +static int +cifs_setlk(struct file *file, struct file_lock *flock, __u8 type, + bool wait_flag, bool posix_lck, int lock, int unlock, int xid) +{ + int rc = 0; + __u64 length = 1 + flock->fl_end - flock->fl_start; + struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data; + struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); + struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode); + __u16 netfid = cfile->netfid; + + if (posix_lck) { + int posix_lock_type; + + rc = cifs_posix_lock_set(file, flock); + if (!rc || rc < 0) + return rc; + + if (type & LOCKING_ANDX_SHARED_LOCK) + posix_lock_type = CIFS_RDLCK; + else + posix_lock_type = CIFS_WRLCK; + + if (unlock == 1) + posix_lock_type = CIFS_UNLCK; + + rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid, + 0 /* set */, length, flock, + posix_lock_type, wait_flag); + goto out; + } + + if (lock) { + struct cifsLockInfo *lock; + + lock = cifs_lock_init(flock->fl_start, length, type, netfid); + if (!lock) + return -ENOMEM; + + rc = cifs_lock_add_if(cinode, lock, wait_flag); + if (rc < 0) + kfree(lock); + if (rc <= 0) + goto out; + + rc = CIFSSMBLock(xid, tcon, netfid, current->tgid, length, + flock->fl_start, 0, 1, type, wait_flag, 0); + if (rc) { + kfree(lock); + goto out; + } + + cifs_lock_add(cinode, lock); + } else if (unlock) + rc = cifs_unlock_range(cfile, flock, xid); + +out: + if (flock->fl_flags & FL_POSIX) + posix_lock_file_wait(file, flock); + return rc; +} + +int cifs_lock(struct file *file, int cmd, struct file_lock *flock) +{ + int rc, xid; + int lock = 0, unlock = 0; + bool wait_flag = false; + bool posix_lck = false; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *tcon; + struct cifsInodeInfo *cinode; + struct cifsFileInfo *cfile; + __u16 netfid; + __u8 type; + + rc = -EACCES; + xid = GetXid(); + + cFYI(1, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld " + "end: %lld", cmd, flock->fl_flags, flock->fl_type, + flock->fl_start, flock->fl_end); + + cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag); + + cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + cfile = (struct cifsFileInfo *)file->private_data; + tcon = tlink_tcon(cfile->tlink); + netfid = cfile->netfid; + cinode = CIFS_I(file->f_path.dentry->d_inode); + + 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_lck = true; + /* + * 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)) { + rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid); + FreeXid(xid); + return rc; + } + + if (!lock && !unlock) { + /* + * if no lock or unlock then nothing to do since we do not + * know what it is + */ + FreeXid(xid); + return -EOPNOTSUPP; + } + + rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock, + xid); + FreeXid(xid); + return rc; +} + +/* + * update the file size (if needed) after a write. Should be called with + * the inode->i_lock held + */ +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; +} + +static ssize_t cifs_write(struct cifsFileInfo *open_file, __u32 pid, + 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 cifs_tcon *pTcon; + int xid; + struct dentry *dentry = open_file->dentry; + struct cifsInodeInfo *cifsi = CIFS_I(dentry->d_inode); + struct cifs_io_parms io_parms; + + cifs_sb = CIFS_SB(dentry->d_sb); + + cFYI(1, "write %zd bytes to offset %lld of %s", write_size, + *poffset, dentry->d_name.name); + + pTcon = tlink_tcon(open_file->tlink); + + xid = GetXid(); + + for (total_written = 0; write_size > total_written; + total_written += bytes_written) { + rc = -EAGAIN; + while (rc == -EAGAIN) { + struct kvec iov[2]; + unsigned int len; + + 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(open_file, false); + if (rc != 0) + break; + } + + 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; + io_parms.netfid = open_file->netfid; + io_parms.pid = pid; + io_parms.tcon = pTcon; + io_parms.offset = *poffset; + io_parms.length = len; + rc = CIFSSMBWrite2(xid, &io_parms, &bytes_written, iov, + 1, 0); + } + if (rc || (bytes_written == 0)) { + if (total_written) + break; + else { + FreeXid(xid); + return rc; + } + } else { + spin_lock(&dentry->d_inode->i_lock); + cifs_update_eof(cifsi, *poffset, bytes_written); + spin_unlock(&dentry->d_inode->i_lock); + *poffset += bytes_written; + } + } + + cifs_stats_bytes_written(pTcon, total_written); + + if (total_written > 0) { + spin_lock(&dentry->d_inode->i_lock); + if (*poffset > dentry->d_inode->i_size) + i_size_write(dentry->d_inode, *poffset); + spin_unlock(&dentry->d_inode->i_lock); + } + mark_inode_dirty_sync(dentry->d_inode); + FreeXid(xid); + return total_written; +} + +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; + + spin_lock(&cifs_file_list_lock); + /* 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 (fsuid_only && open_file->uid != current_fsuid()) + continue; + if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) { + if (!open_file->invalidHandle) { + /* found a good file */ + /* lock it so it will not be closed on us */ + cifsFileInfo_get(open_file); + spin_unlock(&cifs_file_list_lock); + 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 */ + } + spin_unlock(&cifs_file_list_lock); + return NULL; +} + +struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode, + bool fsuid_only) +{ + struct cifsFileInfo *open_file, *inv_file = NULL; + struct cifs_sb_info *cifs_sb; + bool any_available = false; + int rc; + unsigned int refind = 0; + + /* 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; + } + + 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; + + spin_lock(&cifs_file_list_lock); +refind_writable: + if (refind > MAX_REOPEN_ATT) { + spin_unlock(&cifs_file_list_lock); + return NULL; + } + list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { + if (!any_available && open_file->pid != current->tgid) + continue; + if (fsuid_only && open_file->uid != current_fsuid()) + continue; + if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { + if (!open_file->invalidHandle) { + /* found a good writable file */ + cifsFileInfo_get(open_file); + spin_unlock(&cifs_file_list_lock); + return open_file; + } else { + if (!inv_file) + inv_file = open_file; + } + } + } + /* couldn't find useable FH with same pid, try any available */ + if (!any_available) { + any_available = true; + goto refind_writable; + } + + if (inv_file) { + any_available = false; + cifsFileInfo_get(inv_file); + } + + spin_unlock(&cifs_file_list_lock); + + if (inv_file) { + rc = cifs_reopen_file(inv_file, false); + if (!rc) + return inv_file; + else { + spin_lock(&cifs_file_list_lock); + list_move_tail(&inv_file->flist, + &cifs_inode->openFileList); + spin_unlock(&cifs_file_list_lock); + cifsFileInfo_put(inv_file); + spin_lock(&cifs_file_list_lock); + ++refind; + goto refind_writable; + } + } + + 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 inode *inode; + struct cifsFileInfo *open_file; + + if (!mapping || !mapping->host) + return -EFAULT; + + inode = page->mapping->host; + + 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, open_file->pid, + 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; +} + +/* + * Marshal up the iov array, reserving the first one for the header. Also, + * set wdata->bytes. + */ +static void +cifs_writepages_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata) +{ + int i; + struct inode *inode = wdata->cfile->dentry->d_inode; + loff_t size = i_size_read(inode); + + /* marshal up the pages into iov array */ + wdata->bytes = 0; + for (i = 0; i < wdata->nr_pages; i++) { + iov[i + 1].iov_len = min(size - page_offset(wdata->pages[i]), + (loff_t)PAGE_CACHE_SIZE); + iov[i + 1].iov_base = kmap(wdata->pages[i]); + wdata->bytes += iov[i + 1].iov_len; + } +} + +static int cifs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb); + bool done = false, scanned = false, range_whole = false; + pgoff_t end, index; + struct cifs_writedata *wdata; + struct page *page; + int rc = 0; + + /* + * If wsize is smaller than 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); + + 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 = true; + scanned = true; + } +retry: + while (!done && index <= end) { + unsigned int i, nr_pages, found_pages; + pgoff_t next = 0, tofind; + struct page **pages; + + tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1, + end - index) + 1; + + wdata = cifs_writedata_alloc((unsigned int)tofind, + cifs_writev_complete); + if (!wdata) { + rc = -ENOMEM; + break; + } + + /* + * find_get_pages_tag seems to return a max of 256 on each + * iteration, so we must call it several times in order to + * fill the array or the wsize is effectively limited to + * 256 * PAGE_CACHE_SIZE. + */ + found_pages = 0; + pages = wdata->pages; + do { + nr_pages = find_get_pages_tag(mapping, &index, + PAGECACHE_TAG_DIRTY, + tofind, pages); + found_pages += nr_pages; + tofind -= nr_pages; + pages += nr_pages; + } while (nr_pages && tofind && index <= end); + + if (found_pages == 0) { + kref_put(&wdata->refcount, cifs_writedata_release); + break; + } + + nr_pages = 0; + for (i = 0; i < found_pages; i++) { + page = wdata->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 (nr_pages == 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 = true; + 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 = true; + unlock_page(page); + end_page_writeback(page); + break; + } + + wdata->pages[i] = page; + next = page->index + 1; + ++nr_pages; + } + + /* reset index to refind any pages skipped */ + if (nr_pages == 0) + index = wdata->pages[0]->index + 1; + + /* put any pages we aren't going to use */ + for (i = nr_pages; i < found_pages; i++) { + page_cache_release(wdata->pages[i]); + wdata->pages[i] = NULL; + } + + /* nothing to write? */ + if (nr_pages == 0) { + kref_put(&wdata->refcount, cifs_writedata_release); + continue; + } + + wdata->sync_mode = wbc->sync_mode; + wdata->nr_pages = nr_pages; + wdata->offset = page_offset(wdata->pages[0]); + wdata->marshal_iov = cifs_writepages_marshal_iov; + + do { + if (wdata->cfile != NULL) + cifsFileInfo_put(wdata->cfile); + wdata->cfile = find_writable_file(CIFS_I(mapping->host), + false); + if (!wdata->cfile) { + cERROR(1, "No writable handles for inode"); + rc = -EBADF; + break; + } + wdata->pid = wdata->cfile->pid; + rc = cifs_async_writev(wdata); + } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN); + + for (i = 0; i < nr_pages; ++i) + unlock_page(wdata->pages[i]); + + /* send failure -- clean up the mess */ + if (rc != 0) { + for (i = 0; i < nr_pages; ++i) { + if (rc == -EAGAIN) + redirty_page_for_writepage(wbc, + wdata->pages[i]); + else + SetPageError(wdata->pages[i]); + end_page_writeback(wdata->pages[i]); + page_cache_release(wdata->pages[i]); + } + if (rc != -EAGAIN) + mapping_set_error(mapping, rc); + } + kref_put(&wdata->refcount, cifs_writedata_release); + + wbc->nr_to_write -= nr_pages; + if (wbc->nr_to_write <= 0) + done = true; + + index = next; + } + + 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 = true; + index = 0; + goto retry; + } + + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) + mapping->writeback_index = index; + + return rc; +} + +static int +cifs_writepage_locked(struct page *page, struct writeback_control *wbc) +{ + int rc; + 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); +retry_write: + rc = cifs_partialpagewrite(page, 0, PAGE_CACHE_SIZE); + if (rc == -EAGAIN && wbc->sync_mode == WB_SYNC_ALL) + goto retry_write; + else if (rc == -EAGAIN) + redirty_page_for_writepage(wbc, page); + else if (rc != 0) + SetPageError(page); + else + SetPageUptodate(page); + end_page_writeback(page); + page_cache_release(page); + FreeXid(xid); + return rc; +} + +static int cifs_writepage(struct page *page, struct writeback_control *wbc) +{ + int rc = cifs_writepage_locked(page, wbc); + unlock_page(page); + 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; + struct cifsFileInfo *cfile = file->private_data; + struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb); + __u32 pid; + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) + pid = cfile->pid; + else + pid = current->tgid; + + 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(cfile, pid, 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_strict_fsync(struct file *file, loff_t start, loff_t end, + int datasync) +{ + int xid; + int rc = 0; + struct cifs_tcon *tcon; + struct cifsFileInfo *smbfile = file->private_data; + struct inode *inode = file->f_path.dentry->d_inode; + struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + + rc = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (rc) + return rc; + mutex_lock(&inode->i_mutex); + + xid = GetXid(); + + cFYI(1, "Sync file - name: %s datasync: 0x%x", + file->f_path.dentry->d_name.name, datasync); + + if (!CIFS_I(inode)->clientCanCacheRead) { + rc = cifs_invalidate_mapping(inode); + if (rc) { + cFYI(1, "rc: %d during invalidate phase", rc); + rc = 0; /* don't care about it in fsync */ + } + } + + tcon = tlink_tcon(smbfile->tlink); + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) + rc = CIFSSMBFlush(xid, tcon, smbfile->netfid); + + FreeXid(xid); + mutex_unlock(&inode->i_mutex); + return rc; +} + +int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + int xid; + int rc = 0; + struct cifs_tcon *tcon; + struct cifsFileInfo *smbfile = file->private_data; + struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + struct inode *inode = file->f_mapping->host; + + rc = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (rc) + return rc; + mutex_lock(&inode->i_mutex); + + xid = GetXid(); + + cFYI(1, "Sync file - name: %s datasync: 0x%x", + file->f_path.dentry->d_name.name, datasync); + + tcon = tlink_tcon(smbfile->tlink); + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) + rc = CIFSSMBFlush(xid, tcon, smbfile->netfid); + + FreeXid(xid); + mutex_unlock(&inode->i_mutex); + return rc; +} + +/* + * 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; + + if (file->f_mode & FMODE_WRITE) + rc = filemap_write_and_wait(inode->i_mapping); + + cFYI(1, "Flush inode %p file %p rc %d", inode, file, rc); + + return rc; +} + +static int +cifs_write_allocate_pages(struct page **pages, unsigned long num_pages) +{ + int rc = 0; + unsigned long i; + + for (i = 0; i < num_pages; i++) { + pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM); + if (!pages[i]) { + /* + * save number of pages we have already allocated and + * return with ENOMEM error + */ + num_pages = i; + rc = -ENOMEM; + break; + } + } + + if (rc) { + for (i = 0; i < num_pages; i++) + put_page(pages[i]); + } + return rc; +} + +static inline +size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len) +{ + size_t num_pages; + size_t clen; + + clen = min_t(const size_t, len, wsize); + num_pages = DIV_ROUND_UP(clen, PAGE_SIZE); + + if (cur_len) + *cur_len = clen; + + return num_pages; +} + +static void +cifs_uncached_marshal_iov(struct kvec *iov, struct cifs_writedata *wdata) +{ + int i; + size_t bytes = wdata->bytes; + + /* marshal up the pages into iov array */ + for (i = 0; i < wdata->nr_pages; i++) { + iov[i + 1].iov_len = min_t(size_t, bytes, PAGE_SIZE); + iov[i + 1].iov_base = kmap(wdata->pages[i]); + bytes -= iov[i + 1].iov_len; + } +} + +static void +cifs_uncached_writev_complete(struct work_struct *work) +{ + int i; + struct cifs_writedata *wdata = container_of(work, + struct cifs_writedata, work); + struct inode *inode = wdata->cfile->dentry->d_inode; + struct cifsInodeInfo *cifsi = CIFS_I(inode); + + spin_lock(&inode->i_lock); + cifs_update_eof(cifsi, wdata->offset, wdata->bytes); + if (cifsi->server_eof > inode->i_size) + i_size_write(inode, cifsi->server_eof); + spin_unlock(&inode->i_lock); + + complete(&wdata->done); + + if (wdata->result != -EAGAIN) { + for (i = 0; i < wdata->nr_pages; i++) + put_page(wdata->pages[i]); + } + + kref_put(&wdata->refcount, cifs_writedata_release); +} + +/* attempt to send write to server, retry on any -EAGAIN errors */ +static int +cifs_uncached_retry_writev(struct cifs_writedata *wdata) +{ + int rc; + + do { + if (wdata->cfile->invalidHandle) { + rc = cifs_reopen_file(wdata->cfile, false); + if (rc != 0) + continue; + } + rc = cifs_async_writev(wdata); + } while (rc == -EAGAIN); + + return rc; +} + +static ssize_t +cifs_iovec_write(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *poffset) +{ + unsigned long nr_pages, i; + size_t copied, len, cur_len; + ssize_t total_written = 0; + loff_t offset; + struct iov_iter it; + struct cifsFileInfo *open_file; + struct cifs_tcon *tcon; + struct cifs_sb_info *cifs_sb; + struct cifs_writedata *wdata, *tmp; + struct list_head wdata_list; + int rc; + pid_t pid; + + len = iov_length(iov, nr_segs); + if (!len) + return 0; + + rc = generic_write_checks(file, poffset, &len, 0); + if (rc) + return rc; + + INIT_LIST_HEAD(&wdata_list); + cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + open_file = file->private_data; + tcon = tlink_tcon(open_file->tlink); + offset = *poffset; + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) + pid = open_file->pid; + else + pid = current->tgid; + + iov_iter_init(&it, iov, nr_segs, len, 0); + do { + size_t save_len; + + nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len); + wdata = cifs_writedata_alloc(nr_pages, + cifs_uncached_writev_complete); + if (!wdata) { + rc = -ENOMEM; + break; + } + + rc = cifs_write_allocate_pages(wdata->pages, nr_pages); + if (rc) { + kfree(wdata); + break; + } + + save_len = cur_len; + for (i = 0; i < nr_pages; i++) { + copied = min_t(const size_t, cur_len, PAGE_SIZE); + copied = iov_iter_copy_from_user(wdata->pages[i], &it, + 0, copied); + cur_len -= copied; + iov_iter_advance(&it, copied); + } + cur_len = save_len - cur_len; + + wdata->sync_mode = WB_SYNC_ALL; + wdata->nr_pages = nr_pages; + wdata->offset = (__u64)offset; + wdata->cfile = cifsFileInfo_get(open_file); + wdata->pid = pid; + wdata->bytes = cur_len; + wdata->marshal_iov = cifs_uncached_marshal_iov; + rc = cifs_uncached_retry_writev(wdata); + if (rc) { + kref_put(&wdata->refcount, cifs_writedata_release); + break; + } + + list_add_tail(&wdata->list, &wdata_list); + offset += cur_len; + len -= cur_len; + } while (len > 0); + + /* + * If at least one write was successfully sent, then discard any rc + * value from the later writes. If the other write succeeds, then + * we'll end up returning whatever was written. If it fails, then + * we'll get a new rc value from that. + */ + if (!list_empty(&wdata_list)) + rc = 0; + + /* + * Wait for and collect replies for any successful sends in order of + * increasing offset. Once an error is hit or we get a fatal signal + * while waiting, then return without waiting for any more replies. + */ +restart_loop: + list_for_each_entry_safe(wdata, tmp, &wdata_list, list) { + if (!rc) { + /* FIXME: freezable too? */ + rc = wait_for_completion_killable(&wdata->done); + if (rc) + rc = -EINTR; + else if (wdata->result) + rc = wdata->result; + else + total_written += wdata->bytes; + + /* resend call if it's a retryable error */ + if (rc == -EAGAIN) { + rc = cifs_uncached_retry_writev(wdata); + goto restart_loop; + } + } + list_del_init(&wdata->list); + kref_put(&wdata->refcount, cifs_writedata_release); + } + + if (total_written > 0) + *poffset += total_written; + + cifs_stats_bytes_written(tcon, total_written); + return total_written ? total_written : (ssize_t)rc; +} + +ssize_t cifs_user_writev(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + ssize_t written; + struct inode *inode; + + inode = iocb->ki_filp->f_path.dentry->d_inode; + + /* + * BB - optimize the way when signing is disabled. We can drop this + * extra memory-to-memory copying and use iovec buffers for constructing + * write request. + */ + + written = cifs_iovec_write(iocb->ki_filp, iov, nr_segs, &pos); + if (written > 0) { + CIFS_I(inode)->invalid_mapping = true; + iocb->ki_pos = pos; + } + + return written; +} + +ssize_t cifs_strict_writev(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct inode *inode; + + inode = iocb->ki_filp->f_path.dentry->d_inode; + + if (CIFS_I(inode)->clientCanCacheAll) + return generic_file_aio_write(iocb, iov, nr_segs, pos); + + /* + * In strict cache mode we need to write the data to the server exactly + * from the pos to pos+len-1 rather than flush all affected pages + * because it may cause a error with mandatory locks on these pages but + * not on the region from pos to ppos+len-1. + */ + + return cifs_user_writev(iocb, iov, nr_segs, pos); +} + +static ssize_t +cifs_iovec_read(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *poffset) +{ + int rc; + int xid; + ssize_t total_read; + unsigned int bytes_read = 0; + size_t len, cur_len; + int iov_offset = 0; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *pTcon; + struct cifsFileInfo *open_file; + struct smb_com_read_rsp *pSMBr; + struct cifs_io_parms io_parms; + char *read_data; + unsigned int rsize; + __u32 pid; + + if (!nr_segs) + return 0; + + len = iov_length(iov, nr_segs); + if (!len) + return 0; + + xid = GetXid(); + cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + + /* FIXME: set up handlers for larger reads and/or convert to async */ + rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize); + + open_file = file->private_data; + pTcon = tlink_tcon(open_file->tlink); + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) + pid = open_file->pid; + else + pid = current->tgid; + + if ((file->f_flags & O_ACCMODE) == O_WRONLY) + cFYI(1, "attempting read on write only file instance"); + + for (total_read = 0; total_read < len; total_read += bytes_read) { + cur_len = min_t(const size_t, len - total_read, rsize); + rc = -EAGAIN; + read_data = NULL; + + while (rc == -EAGAIN) { + int buf_type = CIFS_NO_BUFFER; + if (open_file->invalidHandle) { + rc = cifs_reopen_file(open_file, true); + if (rc != 0) + break; + } + io_parms.netfid = open_file->netfid; + io_parms.pid = pid; + io_parms.tcon = pTcon; + io_parms.offset = *poffset; + io_parms.length = cur_len; + rc = CIFSSMBRead(xid, &io_parms, &bytes_read, + &read_data, &buf_type); + pSMBr = (struct smb_com_read_rsp *)read_data; + if (read_data) { + char *data_offset = read_data + 4 + + le16_to_cpu(pSMBr->DataOffset); + if (memcpy_toiovecend(iov, data_offset, + iov_offset, bytes_read)) + rc = -EFAULT; + if (buf_type == CIFS_SMALL_BUFFER) + cifs_small_buf_release(read_data); + else if (buf_type == CIFS_LARGE_BUFFER) + cifs_buf_release(read_data); + read_data = NULL; + iov_offset += bytes_read; + } + } + + 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; +} + +ssize_t cifs_user_readv(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + ssize_t read; + + read = cifs_iovec_read(iocb->ki_filp, iov, nr_segs, &pos); + if (read > 0) + iocb->ki_pos = pos; + + return read; +} + +ssize_t cifs_strict_readv(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct inode *inode; + + inode = iocb->ki_filp->f_path.dentry->d_inode; + + if (CIFS_I(inode)->clientCanCacheRead) + return generic_file_aio_read(iocb, iov, nr_segs, pos); + + /* + * In strict cache mode we need to read from the server all the time + * if we don't have level II oplock because the server can delay mtime + * change - so we can't make a decision about inode invalidating. + * And we can also fail with pagereading if there are mandatory locks + * on pages affected by this read but not on the region from pos to + * pos+len-1. + */ + + return cifs_user_readv(iocb, iov, nr_segs, pos); +} + +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; + unsigned int rsize; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *pTcon; + int xid; + char *current_offset; + struct cifsFileInfo *open_file; + struct cifs_io_parms io_parms; + int buf_type = CIFS_NO_BUFFER; + __u32 pid; + + xid = GetXid(); + cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + + /* FIXME: set up handlers for larger reads and/or convert to async */ + rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize); + + if (file->private_data == NULL) { + rc = -EBADF; + FreeXid(xid); + return rc; + } + open_file = file->private_data; + pTcon = tlink_tcon(open_file->tlink); + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) + pid = open_file->pid; + else + pid = current->tgid; + + 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(uint, read_size - total_read, 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(uint, current_read_size, + CIFSMaxBufSize); + } + rc = -EAGAIN; + while (rc == -EAGAIN) { + if (open_file->invalidHandle) { + rc = cifs_reopen_file(open_file, true); + if (rc != 0) + break; + } + io_parms.netfid = open_file->netfid; + io_parms.pid = pid; + io_parms.tcon = pTcon; + io_parms.offset = *poffset; + io_parms.length = current_read_size; + rc = CIFSSMBRead(xid, &io_parms, &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; +} + +/* + * If the page is mmap'ed into a process' page tables, then we need to make + * sure that it doesn't change while being written back. + */ +static int +cifs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct page *page = vmf->page; + + lock_page(page); + return VM_FAULT_LOCKED; +} + +static struct vm_operations_struct cifs_file_vm_ops = { + .fault = filemap_fault, + .page_mkwrite = cifs_page_mkwrite, +}; + +int cifs_file_strict_mmap(struct file *file, struct vm_area_struct *vma) +{ + int rc, xid; + struct inode *inode = file->f_path.dentry->d_inode; + + xid = GetXid(); + + if (!CIFS_I(inode)->clientCanCacheRead) { + rc = cifs_invalidate_mapping(inode); + if (rc) + return rc; + } + + rc = generic_file_mmap(file, vma); + if (rc == 0) + vma->vm_ops = &cifs_file_vm_ops; + FreeXid(xid); + return rc; +} + +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); + if (rc == 0) + vma->vm_ops = &cifs_file_vm_ops; + FreeXid(xid); + return rc; +} + +static int cifs_readpages(struct file *file, struct address_space *mapping, + struct list_head *page_list, unsigned num_pages) +{ + int rc; + struct list_head tmplist; + struct cifsFileInfo *open_file = file->private_data; + struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); + unsigned int rsize = cifs_sb->rsize; + pid_t pid; + + /* + * Give up immediately if rsize is too small to read an entire page. + * The VFS will fall back to readpage. We should never reach this + * point however since we set ra_pages to 0 when the rsize is smaller + * than a cache page. + */ + if (unlikely(rsize < PAGE_CACHE_SIZE)) + return 0; + + /* + * 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) + return rc; + + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) + pid = open_file->pid; + else + pid = current->tgid; + + rc = 0; + INIT_LIST_HEAD(&tmplist); + + cFYI(1, "%s: file=%p mapping=%p num_pages=%u", __func__, file, + mapping, num_pages); + + /* + * Start with the page at end of list and move it to private + * list. Do the same with any following pages until we hit + * the rsize limit, hit an index discontinuity, or run out of + * pages. Issue the async read and then start the loop again + * until the list is empty. + * + * Note that list order is important. The page_list is in + * the order of declining indexes. When we put the pages in + * the rdata->pages, then we want them in increasing order. + */ + while (!list_empty(page_list)) { + unsigned int bytes = PAGE_CACHE_SIZE; + unsigned int expected_index; + unsigned int nr_pages = 1; + loff_t offset; + struct page *page, *tpage; + struct cifs_readdata *rdata; + + page = list_entry(page_list->prev, struct page, lru); + + /* + * Lock the page and put it in the cache. Since no one else + * should have access to this page, we're safe to simply set + * PG_locked without checking it first. + */ + __set_page_locked(page); + rc = add_to_page_cache_locked(page, mapping, + page->index, GFP_KERNEL); + + /* give up if we can't stick it in the cache */ + if (rc) { + __clear_page_locked(page); + break; + } + + /* move first page to the tmplist */ + offset = (loff_t)page->index << PAGE_CACHE_SHIFT; + list_move_tail(&page->lru, &tmplist); + + /* now try and add more pages onto the request */ + expected_index = page->index + 1; + list_for_each_entry_safe_reverse(page, tpage, page_list, lru) { + /* discontinuity ? */ + if (page->index != expected_index) + break; + + /* would this page push the read over the rsize? */ + if (bytes + PAGE_CACHE_SIZE > rsize) + break; + + __set_page_locked(page); + if (add_to_page_cache_locked(page, mapping, + page->index, GFP_KERNEL)) { + __clear_page_locked(page); + break; + } + list_move_tail(&page->lru, &tmplist); + bytes += PAGE_CACHE_SIZE; + expected_index++; + nr_pages++; + } + + rdata = cifs_readdata_alloc(nr_pages); + if (!rdata) { + /* best to give up if we're out of mem */ + list_for_each_entry_safe(page, tpage, &tmplist, lru) { + list_del(&page->lru); + lru_cache_add_file(page); + unlock_page(page); + page_cache_release(page); + } + rc = -ENOMEM; + break; + } + + spin_lock(&cifs_file_list_lock); + cifsFileInfo_get(open_file); + spin_unlock(&cifs_file_list_lock); + rdata->cfile = open_file; + rdata->mapping = mapping; + rdata->offset = offset; + rdata->bytes = bytes; + rdata->pid = pid; + list_splice_init(&tmplist, &rdata->pages); + + do { + if (open_file->invalidHandle) { + rc = cifs_reopen_file(open_file, true); + if (rc != 0) + continue; + } + rc = cifs_async_readv(rdata); + } while (rc == -EAGAIN); + + if (rc != 0) { + list_for_each_entry_safe(page, tpage, &rdata->pages, + lru) { + list_del(&page->lru); + lru_cache_add_file(page); + unlock_page(page); + page_cache_release(page); + } + cifs_readdata_free(rdata); + break; + } + } + + 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; + + spin_lock(&cifs_file_list_lock); + list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { + if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { + spin_unlock(&cifs_file_list_lock); + return 1; + } + } + spin_unlock(&cifs_file_list_lock); + 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); +} + +static int cifs_launder_page(struct page *page) +{ + int rc = 0; + loff_t range_start = page_offset(page); + loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = 0, + .range_start = range_start, + .range_end = range_end, + }; + + cFYI(1, "Launder page: %p", page); + + if (clear_page_dirty_for_io(page)) + rc = cifs_writepage_locked(page, &wbc); + + cifs_fscache_invalidate_page(page, page->mapping->host); + return rc; +} + +void cifs_oplock_break(struct work_struct *work) +{ + struct cifsFileInfo *cfile = container_of(work, struct cifsFileInfo, + oplock_break); + struct inode *inode = cfile->dentry->d_inode; + struct cifsInodeInfo *cinode = CIFS_I(inode); + int rc = 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) { + rc = filemap_fdatawait(inode->i_mapping); + mapping_set_error(inode->i_mapping, rc); + invalidate_remote_inode(inode); + } + cFYI(1, "Oplock flush inode %p rc %d", inode, rc); + } + + rc = cifs_push_locks(cfile); + if (rc) + cERROR(1, "Push locks rc = %d", 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->oplock_break_cancelled) { + rc = CIFSSMBLock(0, tlink_tcon(cfile->tlink), cfile->netfid, + current->tgid, 0, 0, 0, 0, + LOCKING_ANDX_OPLOCK_RELEASE, false, + cinode->clientCanCacheRead ? 1 : 0); + cFYI(1, "Oplock release rc = %d", rc); + } +} + +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, + .launder_page = cifs_launder_page, +}; + +/* + * 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, + .launder_page = cifs_launder_page, +}; |