--- /dev/null
+/*
+ * 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;
+ } else if (flags & O_EXCL)
+ cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
+ current->comm, current->tgid);
+
+ 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, unsigned 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;
+
+ cifs_dbg(FYI, "posix open %s\n", 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_remap(cifs_sb));
+ 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 *oplock,
+ struct cifs_fid *fid, unsigned int xid)
+{
+ int rc;
+ int desired_access;
+ int disposition;
+ int create_options = CREATE_NOT_DIR;
+ FILE_ALL_INFO *buf;
+ struct TCP_Server_Info *server = tcon->ses->server;
+ struct cifs_open_parms oparms;
+
+ if (!server->ops->open)
+ return -ENOSYS;
+
+ desired_access = 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;
+
+ oparms.tcon = tcon;
+ oparms.cifs_sb = cifs_sb;
+ oparms.desired_access = desired_access;
+ oparms.create_options = create_options;
+ oparms.disposition = disposition;
+ oparms.path = full_path;
+ oparms.fid = fid;
+ oparms.reconnect = false;
+
+ rc = server->ops->open(xid, &oparms, oplock, buf);
+
+ 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, fid);
+
+out:
+ kfree(buf);
+ return rc;
+}
+
+static bool
+cifs_has_mand_locks(struct cifsInodeInfo *cinode)
+{
+ struct cifs_fid_locks *cur;
+ bool has_locks = false;
+
+ down_read(&cinode->lock_sem);
+ list_for_each_entry(cur, &cinode->llist, llist) {
+ if (!list_empty(&cur->locks)) {
+ has_locks = true;
+ break;
+ }
+ }
+ up_read(&cinode->lock_sem);
+ return has_locks;
+}
+
+struct cifsFileInfo *
+cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
+ struct tcon_link *tlink, __u32 oplock)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = d_inode(dentry);
+ struct cifsInodeInfo *cinode = CIFS_I(inode);
+ struct cifsFileInfo *cfile;
+ struct cifs_fid_locks *fdlocks;
+ struct cifs_tcon *tcon = tlink_tcon(tlink);
+ struct TCP_Server_Info *server = tcon->ses->server;
+
+ cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
+ if (cfile == NULL)
+ return cfile;
+
+ fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
+ if (!fdlocks) {
+ kfree(cfile);
+ return NULL;
+ }
+
+ INIT_LIST_HEAD(&fdlocks->locks);
+ fdlocks->cfile = cfile;
+ cfile->llist = fdlocks;
+ down_write(&cinode->lock_sem);
+ list_add(&fdlocks->llist, &cinode->llist);
+ up_write(&cinode->lock_sem);
+
+ cfile->count = 1;
+ cfile->pid = current->tgid;
+ cfile->uid = current_fsuid();
+ cfile->dentry = dget(dentry);
+ cfile->f_flags = file->f_flags;
+ cfile->invalidHandle = false;
+ cfile->tlink = cifs_get_tlink(tlink);
+ INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
+ mutex_init(&cfile->fh_mutex);
+
+ cifs_sb_active(inode->i_sb);
+
+ /*
+ * If the server returned a read oplock and we have mandatory brlocks,
+ * set oplock level to None.
+ */
+ if (server->ops->is_read_op(oplock) && cifs_has_mand_locks(cinode)) {
+ cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
+ oplock = 0;
+ }
+
+ spin_lock(&cifs_file_list_lock);
+ if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
+ oplock = fid->pending_open->oplock;
+ list_del(&fid->pending_open->olist);
+
+ fid->purge_cache = false;
+ server->ops->set_fid(cfile, fid, oplock);
+
+ list_add(&cfile->tlist, &tcon->openFileList);
+ /* if readable file instance put first in list*/
+ if (file->f_mode & FMODE_READ)
+ list_add(&cfile->flist, &cinode->openFileList);
+ else
+ list_add_tail(&cfile->flist, &cinode->openFileList);
+ spin_unlock(&cifs_file_list_lock);
+
+ if (fid->purge_cache)
+ cifs_zap_mapping(inode);
+
+ file->private_data = cfile;
+ return cfile;
+}
+
+struct cifsFileInfo *
+cifsFileInfo_get(struct cifsFileInfo *cifs_file)
+{
+ spin_lock(&cifs_file_list_lock);
+ cifsFileInfo_get_locked(cifs_file);
+ spin_unlock(&cifs_file_list_lock);
+ return cifs_file;
+}
+
+/*
+ * 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 = d_inode(cifs_file->dentry);
+ struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
+ struct TCP_Server_Info *server = tcon->ses->server;
+ struct cifsInodeInfo *cifsi = CIFS_I(inode);
+ struct super_block *sb = inode->i_sb;
+ struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+ struct cifsLockInfo *li, *tmp;
+ struct cifs_fid fid;
+ struct cifs_pending_open open;
+ bool oplock_break_cancelled;
+
+ spin_lock(&cifs_file_list_lock);
+ if (--cifs_file->count > 0) {
+ spin_unlock(&cifs_file_list_lock);
+ return;
+ }
+
+ if (server->ops->get_lease_key)
+ server->ops->get_lease_key(inode, &fid);
+
+ /* store open in pending opens to make sure we don't miss lease break */
+ cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
+
+ /* remove it from the lists */
+ list_del(&cifs_file->flist);
+ list_del(&cifs_file->tlist);
+
+ if (list_empty(&cifsi->openFileList)) {
+ cifs_dbg(FYI, "closing last open instance for inode %p\n",
+ d_inode(cifs_file->dentry));
+ /*
+ * 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)
+ set_bit(CIFS_INO_INVALID_MAPPING, &cifsi->flags);
+ cifs_set_oplock_level(cifsi, 0);
+ }
+ spin_unlock(&cifs_file_list_lock);
+
+ oplock_break_cancelled = cancel_work_sync(&cifs_file->oplock_break);
+
+ if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
+ struct TCP_Server_Info *server = tcon->ses->server;
+ unsigned int xid;
+
+ xid = get_xid();
+ if (server->ops->close)
+ server->ops->close(xid, tcon, &cifs_file->fid);
+ _free_xid(xid);
+ }
+
+ if (oplock_break_cancelled)
+ cifs_done_oplock_break(cifsi);
+
+ cifs_del_pending_open(&open);
+
+ /*
+ * Delete any outstanding lock records. We'll lose them when the file
+ * is closed anyway.
+ */
+ down_write(&cifsi->lock_sem);
+ list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
+ list_del(&li->llist);
+ cifs_del_lock_waiters(li);
+ kfree(li);
+ }
+ list_del(&cifs_file->llist->llist);
+ kfree(cifs_file->llist);
+ up_write(&cifsi->lock_sem);
+
+ cifs_put_tlink(cifs_file->tlink);
+ dput(cifs_file->dentry);
+ cifs_sb_deactive(sb);
+ kfree(cifs_file);
+}
+
+int cifs_open(struct inode *inode, struct file *file)
+
+{
+ int rc = -EACCES;
+ unsigned int xid;
+ __u32 oplock;
+ struct cifs_sb_info *cifs_sb;
+ struct TCP_Server_Info *server;
+ struct cifs_tcon *tcon;
+ struct tcon_link *tlink;
+ struct cifsFileInfo *cfile = NULL;
+ char *full_path = NULL;
+ bool posix_open_ok = false;
+ struct cifs_fid fid;
+ struct cifs_pending_open open;
+
+ xid = get_xid();
+
+ cifs_sb = CIFS_SB(inode->i_sb);
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink)) {
+ free_xid(xid);
+ return PTR_ERR(tlink);
+ }
+ tcon = tlink_tcon(tlink);
+ server = tcon->ses->server;
+
+ full_path = build_path_from_dentry(file->f_path.dentry);
+ if (full_path == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
+ inode, file->f_flags, full_path);
+
+ if (file->f_flags & O_DIRECT &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) {
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
+ file->f_op = &cifs_file_direct_nobrl_ops;
+ else
+ file->f_op = &cifs_file_direct_ops;
+ }
+
+ if (server->oplocks)
+ oplock = REQ_OPLOCK;
+ else
+ oplock = 0;
+
+ if (!tcon->broken_posix_open && tcon->unix_ext &&
+ cap_unix(tcon->ses) && (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, &fid.netfid, xid);
+ if (rc == 0) {
+ cifs_dbg(FYI, "posix open succeeded\n");
+ posix_open_ok = true;
+ } else if ((rc == -EINVAL) || (rc == -EOPNOTSUPP)) {
+ if (tcon->ses->serverNOS)
+ cifs_dbg(VFS, "server %s of type %s returned unexpected error on SMB posix open, disabling posix open support. Check if server update available.\n",
+ 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 (server->ops->get_lease_key)
+ server->ops->get_lease_key(inode, &fid);
+
+ cifs_add_pending_open(&fid, tlink, &open);
+
+ if (!posix_open_ok) {
+ if (server->ops->get_lease_key)
+ server->ops->get_lease_key(inode, &fid);
+
+ rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,
+ file->f_flags, &oplock, &fid, xid);
+ if (rc) {
+ cifs_del_pending_open(&open);
+ goto out;
+ }
+ }
+
+ cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);
+ if (cfile == NULL) {
+ if (server->ops->close)
+ server->ops->close(xid, tcon, &fid);
+ cifs_del_pending_open(&open);
+ 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 = INVALID_UID, /* no change */
+ .gid = INVALID_GID, /* no change */
+ .ctime = NO_CHANGE_64,
+ .atime = NO_CHANGE_64,
+ .mtime = NO_CHANGE_64,
+ .device = 0,
+ };
+ CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid.netfid,
+ cfile->pid);
+ }
+
+out:
+ kfree(full_path);
+ free_xid(xid);
+ cifs_put_tlink(tlink);
+ return rc;
+}
+
+static int cifs_push_posix_locks(struct cifsFileInfo *cfile);
+
+/*
+ * Try to reacquire byte range locks that were released when session
+ * to server was lost.
+ */
+static int
+cifs_relock_file(struct cifsFileInfo *cfile)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ int rc = 0;
+
+ down_read(&cinode->lock_sem);
+ if (cinode->can_cache_brlcks) {
+ /* can cache locks - no need to relock */
+ up_read(&cinode->lock_sem);
+ return rc;
+ }
+
+ if (cap_unix(tcon->ses) &&
+ (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
+ ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
+ rc = cifs_push_posix_locks(cfile);
+ else
+ rc = tcon->ses->server->ops->push_mand_locks(cfile);
+
+ up_read(&cinode->lock_sem);
+ return rc;
+}
+
+static int
+cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
+{
+ int rc = -EACCES;
+ unsigned int xid;
+ __u32 oplock;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
+ struct cifsInodeInfo *cinode;
+ struct inode *inode;
+ char *full_path = NULL;
+ int desired_access;
+ int disposition = FILE_OPEN;
+ int create_options = CREATE_NOT_DIR;
+ struct cifs_open_parms oparms;
+
+ xid = get_xid();
+ mutex_lock(&cfile->fh_mutex);
+ if (!cfile->invalidHandle) {
+ mutex_unlock(&cfile->fh_mutex);
+ rc = 0;
+ free_xid(xid);
+ return rc;
+ }
+
+ inode = d_inode(cfile->dentry);
+ cifs_sb = CIFS_SB(inode->i_sb);
+ tcon = tlink_tcon(cfile->tlink);
+ server = tcon->ses->server;
+
+ /*
+ * 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(cfile->dentry);
+ if (full_path == NULL) {
+ rc = -ENOMEM;
+ mutex_unlock(&cfile->fh_mutex);
+ free_xid(xid);
+ return rc;
+ }
+
+ cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
+ inode, cfile->f_flags, full_path);
+
+ if (tcon->ses->server->oplocks)
+ oplock = REQ_OPLOCK;
+ else
+ oplock = 0;
+
+ if (tcon->unix_ext && cap_unix(tcon->ses) &&
+ (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 = cfile->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, &cfile->fid.netfid, xid);
+ if (rc == 0) {
+ cifs_dbg(FYI, "posix reopen succeeded\n");
+ oparms.reconnect = true;
+ goto reopen_success;
+ }
+ /*
+ * fallthrough to retry open the old way on errors, especially
+ * in the reconnect path it is important to retry hard
+ */
+ }
+
+ desired_access = cifs_convert_flags(cfile->f_flags);
+
+ if (backup_cred(cifs_sb))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+
+ if (server->ops->get_lease_key)
+ server->ops->get_lease_key(inode, &cfile->fid);
+
+ oparms.tcon = tcon;
+ oparms.cifs_sb = cifs_sb;
+ oparms.desired_access = desired_access;
+ oparms.create_options = create_options;
+ oparms.disposition = disposition;
+ oparms.path = full_path;
+ oparms.fid = &cfile->fid;
+ oparms.reconnect = true;
+
+ /*
+ * Can not refresh inode by passing in file_info buf to be returned by
+ * ops->open 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 = server->ops->open(xid, &oparms, &oplock, NULL);
+ if (rc == -ENOENT && oparms.reconnect == false) {
+ /* durable handle timeout is expired - open the file again */
+ rc = server->ops->open(xid, &oparms, &oplock, NULL);
+ /* indicate that we need to relock the file */
+ oparms.reconnect = true;
+ }
+
+ if (rc) {
+ mutex_unlock(&cfile->fh_mutex);
+ cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
+ cifs_dbg(FYI, "oplock: %d\n", oplock);
+ goto reopen_error_exit;
+ }
+
+reopen_success:
+ cfile->invalidHandle = false;
+ mutex_unlock(&cfile->fh_mutex);
+ cinode = 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 inode info.
+ */
+
+ server->ops->set_fid(cfile, &cfile->fid, oplock);
+ if (oparms.reconnect)
+ cifs_relock_file(cfile);
+
+reopen_error_exit:
+ kfree(full_path);
+ free_xid(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;
+ unsigned int xid;
+ struct cifsFileInfo *cfile = file->private_data;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
+ char *buf;
+
+ cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
+
+ if (cfile == NULL)
+ return rc;
+
+ xid = get_xid();
+ tcon = tlink_tcon(cfile->tlink);
+ server = tcon->ses->server;
+
+ cifs_dbg(FYI, "Freeing private data in close dir\n");
+ spin_lock(&cifs_file_list_lock);
+ if (server->ops->dir_needs_close(cfile)) {
+ cfile->invalidHandle = true;
+ spin_unlock(&cifs_file_list_lock);
+ if (server->ops->close_dir)
+ rc = server->ops->close_dir(xid, tcon, &cfile->fid);
+ else
+ rc = -ENOSYS;
+ cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
+ /* not much we can do if it fails anyway, ignore rc */
+ rc = 0;
+ } else
+ spin_unlock(&cifs_file_list_lock);
+
+ buf = cfile->srch_inf.ntwrk_buf_start;
+ if (buf) {
+ cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
+ cfile->srch_inf.ntwrk_buf_start = NULL;
+ if (cfile->srch_inf.smallBuf)
+ cifs_small_buf_release(buf);
+ else
+ cifs_buf_release(buf);
+ }
+
+ cifs_put_tlink(cfile->tlink);
+ kfree(file->private_data);
+ file->private_data = NULL;
+ /* BB can we lock the filestruct while this is going on? */
+ free_xid(xid);
+ return rc;
+}
+
+static struct cifsLockInfo *
+cifs_lock_init(__u64 offset, __u64 length, __u8 type)
+{
+ struct cifsLockInfo *lock =
+ kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
+ if (!lock)
+ return lock;
+ lock->offset = offset;
+ lock->length = length;
+ lock->type = type;
+ lock->pid = current->tgid;
+ INIT_LIST_HEAD(&lock->blist);
+ init_waitqueue_head(&lock->block_q);
+ return lock;
+}
+
+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);
+ }
+}
+
+#define CIFS_LOCK_OP 0
+#define CIFS_READ_OP 1
+#define CIFS_WRITE_OP 2
+
+/* @rw_check : 0 - no op, 1 - read, 2 - write */
+static bool
+cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
+ __u64 length, __u8 type, struct cifsFileInfo *cfile,
+ struct cifsLockInfo **conf_lock, int rw_check)
+{
+ struct cifsLockInfo *li;
+ struct cifsFileInfo *cur_cfile = fdlocks->cfile;
+ struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
+
+ list_for_each_entry(li, &fdlocks->locks, llist) {
+ if (offset + length <= li->offset ||
+ offset >= li->offset + li->length)
+ continue;
+ if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
+ server->ops->compare_fids(cfile, cur_cfile)) {
+ /* shared lock prevents write op through the same fid */
+ if (!(li->type & server->vals->shared_lock_type) ||
+ rw_check != CIFS_WRITE_OP)
+ continue;
+ }
+ if ((type & server->vals->shared_lock_type) &&
+ ((server->ops->compare_fids(cfile, cur_cfile) &&
+ current->tgid == li->pid) || type == li->type))
+ continue;
+ if (conf_lock)
+ *conf_lock = li;
+ return true;
+ }
+ return false;
+}
+
+bool
+cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
+ __u8 type, struct cifsLockInfo **conf_lock,
+ int rw_check)
+{
+ bool rc = false;
+ struct cifs_fid_locks *cur;
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+
+ list_for_each_entry(cur, &cinode->llist, llist) {
+ rc = cifs_find_fid_lock_conflict(cur, offset, length, type,
+ cfile, conf_lock, rw_check);
+ if (rc)
+ break;
+ }
+
+ return rc;
+}
+
+/*
+ * 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 cifsFileInfo *cfile, __u64 offset, __u64 length,
+ __u8 type, struct file_lock *flock)
+{
+ int rc = 0;
+ struct cifsLockInfo *conf_lock;
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
+ bool exist;
+
+ down_read(&cinode->lock_sem);
+
+ exist = cifs_find_lock_conflict(cfile, offset, length, type,
+ &conf_lock, CIFS_LOCK_OP);
+ 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 & server->vals->shared_lock_type)
+ 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;
+
+ up_read(&cinode->lock_sem);
+ return rc;
+}
+
+static void
+cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ down_write(&cinode->lock_sem);
+ list_add_tail(&lock->llist, &cfile->llist->locks);
+ up_write(&cinode->lock_sem);
+}
+
+/*
+ * 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 cifsFileInfo *cfile, struct cifsLockInfo *lock,
+ bool wait)
+{
+ struct cifsLockInfo *conf_lock;
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ bool exist;
+ int rc = 0;
+
+try_again:
+ exist = false;
+ down_write(&cinode->lock_sem);
+
+ exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
+ lock->type, &conf_lock, CIFS_LOCK_OP);
+ if (!exist && cinode->can_cache_brlcks) {
+ list_add_tail(&lock->llist, &cfile->llist->locks);
+ up_write(&cinode->lock_sem);
+ return rc;
+ }
+
+ if (!exist)
+ rc = 1;
+ else if (!wait)
+ rc = -EACCES;
+ else {
+ list_add_tail(&lock->blist, &conf_lock->blist);
+ up_write(&cinode->lock_sem);
+ rc = wait_event_interruptible(lock->block_q,
+ (lock->blist.prev == &lock->blist) &&
+ (lock->blist.next == &lock->blist));
+ if (!rc)
+ goto try_again;
+ down_write(&cinode->lock_sem);
+ list_del_init(&lock->blist);
+ }
+
+ up_write(&cinode->lock_sem);
+ 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_inode(file));
+ unsigned char saved_type = flock->fl_type;
+
+ if ((flock->fl_flags & FL_POSIX) == 0)
+ return 1;
+
+ down_read(&cinode->lock_sem);
+ posix_test_lock(file, flock);
+
+ if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
+ flock->fl_type = saved_type;
+ rc = 1;
+ }
+
+ up_read(&cinode->lock_sem);
+ 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_inode(file));
+ int rc = 1;
+
+ if ((flock->fl_flags & FL_POSIX) == 0)
+ return rc;
+
+try_again:
+ down_write(&cinode->lock_sem);
+ if (!cinode->can_cache_brlcks) {
+ up_write(&cinode->lock_sem);
+ return rc;
+ }
+
+ rc = posix_lock_file(file, flock, NULL);
+ up_write(&cinode->lock_sem);
+ if (rc == FILE_LOCK_DEFERRED) {
+ rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
+ if (!rc)
+ goto try_again;
+ posix_unblock_lock(flock);
+ }
+ return rc;
+}
+
+int
+cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
+{
+ unsigned int xid;
+ int rc = 0, stored_rc;
+ struct cifsLockInfo *li, *tmp;
+ struct cifs_tcon *tcon;
+ unsigned int num, max_num, max_buf;
+ LOCKING_ANDX_RANGE *buf, *cur;
+ int types[] = {LOCKING_ANDX_LARGE_FILES,
+ LOCKING_ANDX_SHARED_LOCK | LOCKING_ANDX_LARGE_FILES};
+ int i;
+
+ xid = get_xid();
+ tcon = tlink_tcon(cfile->tlink);
+
+ /*
+ * Accessing maxBuf is racy with cifs_reconnect - need to store value
+ * and check it for zero before using.
+ */
+ max_buf = tcon->ses->server->maxBuf;
+ if (!max_buf) {
+ free_xid(xid);
+ return -EINVAL;
+ }
+
+ max_num = (max_buf - sizeof(struct smb_hdr)) /
+ sizeof(LOCKING_ANDX_RANGE);
+ buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
+ if (!buf) {
+ free_xid(xid);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < 2; i++) {
+ cur = buf;
+ num = 0;
+ list_for_each_entry_safe(li, tmp, &cfile->llist->locks, 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->fid.netfid,
+ (__u8)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->fid.netfid,
+ (__u8)types[i], 0, num, buf);
+ if (stored_rc)
+ rc = stored_rc;
+ }
+ }
+
+ kfree(buf);
+ free_xid(xid);
+ return rc;
+}
+
+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 inode *inode = d_inode(cfile->dentry);
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ struct file_lock *flock;
+ struct file_lock_context *flctx = inode->i_flctx;
+ unsigned int count = 0, i;
+ int rc = 0, xid, type;
+ struct list_head locks_to_send, *el;
+ struct lock_to_push *lck, *tmp;
+ __u64 length;
+
+ xid = get_xid();
+
+ if (!flctx)
+ goto out;
+
+ spin_lock(&flctx->flc_lock);
+ list_for_each(el, &flctx->flc_posix) {
+ count++;
+ }
+ spin_unlock(&flctx->flc_lock);
+
+ 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_sem that
+ * protects locking operations of this inode.
+ */
+ for (i = 0; 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;
+ spin_lock(&flctx->flc_lock);
+ list_for_each_entry(flock, &flctx->flc_posix, fl_list) {
+ if (el == &locks_to_send) {
+ /*
+ * The list ended. We don't have enough allocated
+ * structures - something is really wrong.
+ */
+ cifs_dbg(VFS, "Can't push all brlocks!\n");
+ 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->fid.netfid;
+ lck->length = length;
+ lck->type = type;
+ lck->offset = flock->fl_start;
+ }
+ spin_unlock(&flctx->flc_lock);
+
+ list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
+ int stored_rc;
+
+ stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
+ lck->offset, lck->length, NULL,
+ lck->type, 0);
+ if (stored_rc)
+ rc = stored_rc;
+ list_del(&lck->llist);
+ kfree(lck);
+ }
+
+out:
+ free_xid(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 cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ int rc = 0;
+
+ /* we are going to update can_cache_brlcks here - need a write access */
+ down_write(&cinode->lock_sem);
+ if (!cinode->can_cache_brlcks) {
+ up_write(&cinode->lock_sem);
+ return rc;
+ }
+
+ if (cap_unix(tcon->ses) &&
+ (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
+ ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
+ rc = cifs_push_posix_locks(cfile);
+ else
+ rc = tcon->ses->server->ops->push_mand_locks(cfile);
+
+ cinode->can_cache_brlcks = false;
+ up_write(&cinode->lock_sem);
+ return rc;
+}
+
+static void
+cifs_read_flock(struct file_lock *flock, __u32 *type, int *lock, int *unlock,
+ bool *wait_flag, struct TCP_Server_Info *server)
+{
+ if (flock->fl_flags & FL_POSIX)
+ cifs_dbg(FYI, "Posix\n");
+ if (flock->fl_flags & FL_FLOCK)
+ cifs_dbg(FYI, "Flock\n");
+ if (flock->fl_flags & FL_SLEEP) {
+ cifs_dbg(FYI, "Blocking lock\n");
+ *wait_flag = true;
+ }
+ if (flock->fl_flags & FL_ACCESS)
+ cifs_dbg(FYI, "Process suspended by mandatory locking - not implemented yet\n");
+ if (flock->fl_flags & FL_LEASE)
+ cifs_dbg(FYI, "Lease on file - not implemented yet\n");
+ if (flock->fl_flags &
+ (~(FL_POSIX | FL_FLOCK | FL_SLEEP |
+ FL_ACCESS | FL_LEASE | FL_CLOSE)))
+ cifs_dbg(FYI, "Unknown lock flags 0x%x\n", flock->fl_flags);
+
+ *type = server->vals->large_lock_type;
+ if (flock->fl_type == F_WRLCK) {
+ cifs_dbg(FYI, "F_WRLCK\n");
+ *type |= server->vals->exclusive_lock_type;
+ *lock = 1;
+ } else if (flock->fl_type == F_UNLCK) {
+ cifs_dbg(FYI, "F_UNLCK\n");
+ *type |= server->vals->unlock_lock_type;
+ *unlock = 1;
+ /* Check if unlock includes more than one lock range */
+ } else if (flock->fl_type == F_RDLCK) {
+ cifs_dbg(FYI, "F_RDLCK\n");
+ *type |= server->vals->shared_lock_type;
+ *lock = 1;
+ } else if (flock->fl_type == F_EXLCK) {
+ cifs_dbg(FYI, "F_EXLCK\n");
+ *type |= server->vals->exclusive_lock_type;
+ *lock = 1;
+ } else if (flock->fl_type == F_SHLCK) {
+ cifs_dbg(FYI, "F_SHLCK\n");
+ *type |= server->vals->shared_lock_type;
+ *lock = 1;
+ } else
+ cifs_dbg(FYI, "Unknown type of lock\n");
+}
+
+static int
+cifs_getlk(struct file *file, struct file_lock *flock, __u32 type,
+ bool wait_flag, bool posix_lck, unsigned 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 TCP_Server_Info *server = tcon->ses->server;
+ __u16 netfid = cfile->fid.netfid;
+
+ if (posix_lck) {
+ int posix_lock_type;
+
+ rc = cifs_posix_lock_test(file, flock);
+ if (!rc)
+ return rc;
+
+ if (type & server->vals->shared_lock_type)
+ posix_lock_type = CIFS_RDLCK;
+ else
+ posix_lock_type = CIFS_WRLCK;
+ rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
+ flock->fl_start, length, flock,
+ posix_lock_type, wait_flag);
+ return rc;
+ }
+
+ rc = cifs_lock_test(cfile, flock->fl_start, length, type, flock);
+ if (!rc)
+ return rc;
+
+ /* BB we could chain these into one lock request BB */
+ rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length, type,
+ 1, 0, false);
+ if (rc == 0) {
+ rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
+ type, 0, 1, false);
+ flock->fl_type = F_UNLCK;
+ if (rc != 0)
+ cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
+ rc);
+ return 0;
+ }
+
+ if (type & server->vals->shared_lock_type) {
+ flock->fl_type = F_WRLCK;
+ return 0;
+ }
+
+ type &= ~server->vals->exclusive_lock_type;
+
+ rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
+ type | server->vals->shared_lock_type,
+ 1, 0, false);
+ if (rc == 0) {
+ rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
+ type | server->vals->shared_lock_type, 0, 1, false);
+ flock->fl_type = F_RDLCK;
+ if (rc != 0)
+ cifs_dbg(VFS, "Error unlocking previously locked range %d during test of lock\n",
+ rc);
+ } else
+ flock->fl_type = F_WRLCK;
+
+ return 0;
+}
+
+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);
+}
+
+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);
+ }
+}
+
+int
+cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
+ unsigned 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, max_buf;
+ LOCKING_ANDX_RANGE *buf, *cur;
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
+ struct cifsLockInfo *li, *tmp;
+ __u64 length = 1 + flock->fl_end - flock->fl_start;
+ struct list_head tmp_llist;
+
+ INIT_LIST_HEAD(&tmp_llist);
+
+ /*
+ * Accessing maxBuf is racy with cifs_reconnect - need to store value
+ * and check it for zero before using.
+ */
+ max_buf = tcon->ses->server->maxBuf;
+ if (!max_buf)
+ return -EINVAL;
+
+ max_num = (max_buf - sizeof(struct smb_hdr)) /
+ sizeof(LOCKING_ANDX_RANGE);
+ buf = kcalloc(max_num, sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ down_write(&cinode->lock_sem);
+ for (i = 0; i < 2; i++) {
+ cur = buf;
+ num = 0;
+ list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
+ if (flock->fl_start > li->offset ||
+ (flock->fl_start + length) <
+ (li->offset + li->length))
+ continue;
+ if (current->tgid != li->pid)
+ continue;
+ if (types[i] != li->type)
+ continue;
+ if (cinode->can_cache_brlcks) {
+ /*
+ * We can cache brlock requests - simply remove
+ * a lock from the file's list.
+ */
+ list_del(&li->llist);
+ cifs_del_lock_waiters(li);
+ kfree(li);
+ 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));
+ /*
+ * We need to save a lock here to let us add it again to
+ * the file's 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->fid.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 file's list.
+ */
+ cifs_move_llist(&tmp_llist,
+ &cfile->llist->locks);
+ rc = stored_rc;
+ } else
+ /*
+ * The unlock range request succeed -
+ * free the tmp list.
+ */
+ cifs_free_llist(&tmp_llist);
+ cur = buf;
+ num = 0;
+ } else
+ cur++;
+ }
+ if (num) {
+ stored_rc = cifs_lockv(xid, tcon, cfile->fid.netfid,
+ types[i], num, 0, buf);
+ if (stored_rc) {
+ cifs_move_llist(&tmp_llist,
+ &cfile->llist->locks);
+ rc = stored_rc;
+ } else
+ cifs_free_llist(&tmp_llist);
+ }
+ }
+
+ up_write(&cinode->lock_sem);
+ kfree(buf);
+ return rc;
+}
+
+static int
+cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
+ bool wait_flag, bool posix_lck, int lock, int unlock,
+ unsigned 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 TCP_Server_Info *server = tcon->ses->server;
+ struct inode *inode = d_inode(cfile->dentry);
+
+ if (posix_lck) {
+ int posix_lock_type;
+
+ rc = cifs_posix_lock_set(file, flock);
+ if (!rc || rc < 0)
+ return rc;
+
+ if (type & server->vals->shared_lock_type)
+ posix_lock_type = CIFS_RDLCK;
+ else
+ posix_lock_type = CIFS_WRLCK;
+
+ if (unlock == 1)
+ posix_lock_type = CIFS_UNLCK;
+
+ rc = CIFSSMBPosixLock(xid, tcon, cfile->fid.netfid,
+ current->tgid, flock->fl_start, length,
+ NULL, posix_lock_type, wait_flag);
+ goto out;
+ }
+
+ if (lock) {
+ struct cifsLockInfo *lock;
+
+ lock = cifs_lock_init(flock->fl_start, length, type);
+ if (!lock)
+ return -ENOMEM;
+
+ rc = cifs_lock_add_if(cfile, lock, wait_flag);
+ if (rc < 0) {
+ kfree(lock);
+ return rc;
+ }
+ if (!rc)
+ goto out;
+
+ /*
+ * Windows 7 server can delay breaking lease from read to None
+ * if we set a byte-range lock on a file - break it explicitly
+ * before sending the lock to the server to be sure the next
+ * read won't conflict with non-overlapted locks due to
+ * pagereading.
+ */
+ if (!CIFS_CACHE_WRITE(CIFS_I(inode)) &&
+ CIFS_CACHE_READ(CIFS_I(inode))) {
+ cifs_zap_mapping(inode);
+ cifs_dbg(FYI, "Set no oplock for inode=%p due to mand locks\n",
+ inode);
+ CIFS_I(inode)->oplock = 0;
+ }
+
+ rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
+ type, 1, 0, wait_flag);
+ if (rc) {
+ kfree(lock);
+ return rc;
+ }
+
+ cifs_lock_add(cfile, lock);
+ } else if (unlock)
+ rc = server->ops->mand_unlock_range(cfile, flock, xid);
+
+out:
+ if (flock->fl_flags & FL_POSIX && !rc)
+ rc = 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;
+ __u32 type;
+
+ rc = -EACCES;
+ xid = get_xid();
+
+ cifs_dbg(FYI, "Lock parm: 0x%x flockflags: 0x%x flocktype: 0x%x start: %lld end: %lld\n",
+ cmd, flock->fl_flags, flock->fl_type,
+ flock->fl_start, flock->fl_end);
+
+ cfile = (struct cifsFileInfo *)file->private_data;
+ tcon = tlink_tcon(cfile->tlink);
+
+ cifs_read_flock(flock, &type, &lock, &unlock, &wait_flag,
+ tcon->ses->server);
+
+ cifs_sb = CIFS_FILE_SB(file);
+ netfid = cfile->fid.netfid;
+ cinode = CIFS_I(file_inode(file));
+
+ if (cap_unix(tcon->ses) &&
+ (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);
+ free_xid(xid);
+ return rc;
+ }
+
+ if (!lock && !unlock) {
+ /*
+ * if no lock or unlock then nothing to do since we do not
+ * know what it is
+ */
+ free_xid(xid);
+ return -EOPNOTSUPP;
+ }
+
+ rc = cifs_setlk(file, flock, type, wait_flag, posix_lck, lock, unlock,
+ xid);
+ free_xid(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 *offset)
+{
+ int rc = 0;
+ unsigned int bytes_written = 0;
+ unsigned int total_written;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
+ unsigned int xid;
+ struct dentry *dentry = open_file->dentry;
+ struct cifsInodeInfo *cifsi = CIFS_I(d_inode(dentry));
+ struct cifs_io_parms io_parms;
+
+ cifs_sb = CIFS_SB(dentry->d_sb);
+
+ cifs_dbg(FYI, "write %zd bytes to offset %lld of %pd\n",
+ write_size, *offset, dentry);
+
+ tcon = tlink_tcon(open_file->tlink);
+ server = tcon->ses->server;
+
+ if (!server->ops->sync_write)
+ return -ENOSYS;
+
+ xid = get_xid();
+
+ 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(server->ops->wp_retry_size(d_inode(dentry)),
+ (unsigned int)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.pid = pid;
+ io_parms.tcon = tcon;
+ io_parms.offset = *offset;
+ io_parms.length = len;
+ rc = server->ops->sync_write(xid, &open_file->fid,
+ &io_parms, &bytes_written, iov, 1);
+ }
+ if (rc || (bytes_written == 0)) {
+ if (total_written)
+ break;
+ else {
+ free_xid(xid);
+ return rc;
+ }
+ } else {
+ spin_lock(&d_inode(dentry)->i_lock);
+ cifs_update_eof(cifsi, *offset, bytes_written);
+ spin_unlock(&d_inode(dentry)->i_lock);
+ *offset += bytes_written;
+ }
+ }
+
+ cifs_stats_bytes_written(tcon, total_written);
+
+ if (total_written > 0) {
+ spin_lock(&d_inode(dentry)->i_lock);
+ if (*offset > d_inode(dentry)->i_size)
+ i_size_write(d_inode(dentry), *offset);
+ spin_unlock(&d_inode(dentry)->i_lock);
+ }
+ mark_inode_dirty_sync(d_inode(dentry));
+ free_xid(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 && !uid_eq(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_locked(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) {
+ cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
+ 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 && !uid_eq(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_locked(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_locked(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;
+ inv_file = NULL;
+ 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 {
+ cifs_dbg(FYI, "No writeable filehandles for inode\n");
+ rc = -EIO;
+ }
+
+ kunmap(page);
+ return rc;
+}
+
+static struct cifs_writedata *
+wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
+ pgoff_t end, pgoff_t *index,
+ unsigned int *found_pages)
+{
+ unsigned int nr_pages;
+ struct page **pages;
+ struct cifs_writedata *wdata;
+
+ wdata = cifs_writedata_alloc((unsigned int)tofind,
+ cifs_writev_complete);
+ if (!wdata)
+ return NULL;
+
+ /*
+ * 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);
+
+ return wdata;
+}
+
+static unsigned int
+wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
+ struct address_space *mapping,
+ struct writeback_control *wbc,
+ pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
+{
+ unsigned int nr_pages = 0, i;
+ struct page *page;
+
+ 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) >= i_size_read(mapping->host)) {
+ *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;
+ }
+
+ return nr_pages;
+}
+
+static int
+wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
+ struct address_space *mapping, struct writeback_control *wbc)
+{
+ int rc = 0;
+ struct TCP_Server_Info *server;
+ unsigned int i;
+
+ wdata->sync_mode = wbc->sync_mode;
+ wdata->nr_pages = nr_pages;
+ wdata->offset = page_offset(wdata->pages[0]);
+ wdata->pagesz = PAGE_CACHE_SIZE;
+ wdata->tailsz = min(i_size_read(mapping->host) -
+ page_offset(wdata->pages[nr_pages - 1]),
+ (loff_t)PAGE_CACHE_SIZE);
+ wdata->bytes = ((nr_pages - 1) * PAGE_CACHE_SIZE) + wdata->tailsz;
+
+ if (wdata->cfile != NULL)
+ cifsFileInfo_put(wdata->cfile);
+ wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
+ if (!wdata->cfile) {
+ cifs_dbg(VFS, "No writable handles for inode\n");
+ rc = -EBADF;
+ } else {
+ wdata->pid = wdata->cfile->pid;
+ server = tlink_tcon(wdata->cfile->tlink)->ses->server;
+ rc = server->ops->async_writev(wdata, cifs_writedata_release);
+ }
+
+ for (i = 0; i < nr_pages; ++i)
+ unlock_page(wdata->pages[i]);
+
+ return rc;
+}
+
+static int cifs_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
+ struct TCP_Server_Info *server;
+ bool done = false, scanned = false, range_whole = false;
+ pgoff_t end, index;
+ struct cifs_writedata *wdata;
+ 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;
+ }
+ server = cifs_sb_master_tcon(cifs_sb)->ses->server;
+retry:
+ while (!done && index <= end) {
+ unsigned int i, nr_pages, found_pages, wsize, credits;
+ pgoff_t next = 0, tofind, saved_index = index;
+
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
+ &wsize, &credits);
+ if (rc)
+ break;
+
+ tofind = min((wsize / PAGE_CACHE_SIZE) - 1, end - index) + 1;
+
+ wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
+ &found_pages);
+ if (!wdata) {
+ rc = -ENOMEM;
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ if (found_pages == 0) {
+ kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
+ end, &index, &next, &done);
+
+ /* nothing to write? */
+ if (nr_pages == 0) {
+ kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake_if(server, credits, 0);
+ continue;
+ }
+
+ wdata->credits = credits;
+
+ rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
+
+ /* send failure -- clean up the mess */
+ if (rc != 0) {
+ add_credits_and_wake_if(server, wdata->credits, 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);
+
+ if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
+ index = saved_index;
+ continue;
+ }
+
+ 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;
+ unsigned int xid;
+
+ xid = get_xid();
+/* BB add check for wbc flags */
+ page_cache_get(page);
+ if (!PageUptodate(page))
+ cifs_dbg(FYI, "ppw - page not up to date\n");
+
+ /*
+ * 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);
+ free_xid(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;
+
+ cifs_dbg(FYI, "write_end for page %p from pos %lld with %d bytes\n",
+ 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);
+ unsigned int xid;
+
+ xid = get_xid();
+ /* 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);
+
+ free_xid(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)
+{
+ unsigned int xid;
+ int rc = 0;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
+ struct cifsFileInfo *smbfile = file->private_data;
+ struct inode *inode = file_inode(file);
+ 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 = get_xid();
+
+ cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
+ file, datasync);
+
+ if (!CIFS_CACHE_READ(CIFS_I(inode))) {
+ rc = cifs_zap_mapping(inode);
+ if (rc) {
+ cifs_dbg(FYI, "rc: %d during invalidate phase\n", rc);
+ rc = 0; /* don't care about it in fsync */
+ }
+ }
+
+ tcon = tlink_tcon(smbfile->tlink);
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
+ server = tcon->ses->server;
+ if (server->ops->flush)
+ rc = server->ops->flush(xid, tcon, &smbfile->fid);
+ else
+ rc = -ENOSYS;
+ }
+
+ free_xid(xid);
+ mutex_unlock(&inode->i_mutex);
+ return rc;
+}
+
+int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+ unsigned int xid;
+ int rc = 0;
+ struct cifs_tcon *tcon;
+ struct TCP_Server_Info *server;
+ struct cifsFileInfo *smbfile = file->private_data;
+ struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
+ 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 = get_xid();
+
+ cifs_dbg(FYI, "Sync file - name: %pD datasync: 0x%x\n",
+ file, datasync);
+
+ tcon = tlink_tcon(smbfile->tlink);
+ if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
+ server = tcon->ses->server;
+ if (server->ops->flush)
+ rc = server->ops->flush(xid, tcon, &smbfile->fid);
+ else
+ rc = -ENOSYS;
+ }
+
+ free_xid(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_inode(file);
+ int rc = 0;
+
+ if (file->f_mode & FMODE_WRITE)
+ rc = filemap_write_and_wait(inode->i_mapping);
+
+ cifs_dbg(FYI, "Flush inode %p file %p rc %d\n", 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_writedata_release(struct kref *refcount)
+{
+ int i;
+ struct cifs_writedata *wdata = container_of(refcount,
+ struct cifs_writedata, refcount);
+
+ for (i = 0; i < wdata->nr_pages; i++)
+ put_page(wdata->pages[i]);
+ cifs_writedata_release(refcount);
+}
+
+static void
+cifs_uncached_writev_complete(struct work_struct *work)
+{
+ struct cifs_writedata *wdata = container_of(work,
+ struct cifs_writedata, work);
+ struct inode *inode = d_inode(wdata->cfile->dentry);
+ 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);
+
+ kref_put(&wdata->refcount, cifs_uncached_writedata_release);
+}
+
+static int
+wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
+ size_t *len, unsigned long *num_pages)
+{
+ size_t save_len, copied, bytes, cur_len = *len;
+ unsigned long i, nr_pages = *num_pages;
+
+ save_len = cur_len;
+ for (i = 0; i < nr_pages; i++) {
+ bytes = min_t(const size_t, cur_len, PAGE_SIZE);
+ copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
+ cur_len -= copied;
+ /*
+ * If we didn't copy as much as we expected, then that
+ * may mean we trod into an unmapped area. Stop copying
+ * at that point. On the next pass through the big
+ * loop, we'll likely end up getting a zero-length
+ * write and bailing out of it.
+ */
+ if (copied < bytes)
+ break;
+ }
+ cur_len = save_len - cur_len;
+ *len = cur_len;
+
+ /*
+ * If we have no data to send, then that probably means that
+ * the copy above failed altogether. That's most likely because
+ * the address in the iovec was bogus. Return -EFAULT and let
+ * the caller free anything we allocated and bail out.
+ */
+ if (!cur_len)
+ return -EFAULT;
+
+ /*
+ * i + 1 now represents the number of pages we actually used in
+ * the copy phase above.
+ */
+ *num_pages = i + 1;
+ return 0;
+}
+
+static int
+cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
+ struct cifsFileInfo *open_file,
+ struct cifs_sb_info *cifs_sb, struct list_head *wdata_list)
+{
+ int rc = 0;
+ size_t cur_len;
+ unsigned long nr_pages, num_pages, i;
+ struct cifs_writedata *wdata;
+ struct iov_iter saved_from;
+ loff_t saved_offset = offset;
+ pid_t pid;
+ struct TCP_Server_Info *server;
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
+ pid = open_file->pid;
+ else
+ pid = current->tgid;
+
+ server = tlink_tcon(open_file->tlink)->ses->server;
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
+ do {
+ unsigned int wsize, credits;
+
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
+ &wsize, &credits);
+ if (rc)
+ break;
+
+ nr_pages = get_numpages(wsize, len, &cur_len);
+ wdata = cifs_writedata_alloc(nr_pages,
+ cifs_uncached_writev_complete);
+ if (!wdata) {
+ rc = -ENOMEM;
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
+ if (rc) {
+ kfree(wdata);
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ num_pages = nr_pages;
+ rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages);
+ if (rc) {
+ for (i = 0; i < nr_pages; i++)
+ put_page(wdata->pages[i]);
+ kfree(wdata);
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ /*
+ * Bring nr_pages down to the number of pages we actually used,
+ * and free any pages that we didn't use.
+ */
+ for ( ; nr_pages > num_pages; nr_pages--)
+ put_page(wdata->pages[nr_pages - 1]);
+
+ 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->pagesz = PAGE_SIZE;
+ wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
+ wdata->credits = credits;
+
+ if (!wdata->cfile->invalidHandle ||
+ !cifs_reopen_file(wdata->cfile, false))
+ rc = server->ops->async_writev(wdata,
+ cifs_uncached_writedata_release);
+ if (rc) {
+ add_credits_and_wake_if(server, wdata->credits, 0);
+ kref_put(&wdata->refcount,
+ cifs_uncached_writedata_release);
+ if (rc == -EAGAIN) {
+ memcpy(from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(from, offset - saved_offset);
+ continue;
+ }
+ break;
+ }
+
+ list_add_tail(&wdata->list, wdata_list);
+ offset += cur_len;
+ len -= cur_len;
+ } while (len > 0);
+
+ return rc;
+}
+
+ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ ssize_t total_written = 0;
+ struct cifsFileInfo *open_file;
+ struct cifs_tcon *tcon;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_writedata *wdata, *tmp;
+ struct list_head wdata_list;
+ struct iov_iter saved_from;
+ int rc;
+
+ /*
+ * 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.
+ */
+
+ rc = generic_write_checks(iocb, from);
+ if (rc <= 0)
+ return rc;
+
+ INIT_LIST_HEAD(&wdata_list);
+ cifs_sb = CIFS_FILE_SB(file);
+ open_file = file->private_data;
+ tcon = tlink_tcon(open_file->tlink);
+
+ if (!tcon->ses->server->ops->async_writev)
+ return -ENOSYS;
+
+ memcpy(&saved_from, from, sizeof(struct iov_iter));
+
+ rc = cifs_write_from_iter(iocb->ki_pos, iov_iter_count(from), from,
+ open_file, cifs_sb, &wdata_list);
+
+ /*
+ * 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) {
+ struct list_head tmp_list;
+ struct iov_iter tmp_from;
+
+ INIT_LIST_HEAD(&tmp_list);
+ list_del_init(&wdata->list);
+
+ memcpy(&tmp_from, &saved_from,
+ sizeof(struct iov_iter));
+ iov_iter_advance(&tmp_from,
+ wdata->offset - iocb->ki_pos);
+
+ rc = cifs_write_from_iter(wdata->offset,
+ wdata->bytes, &tmp_from,
+ open_file, cifs_sb, &tmp_list);
+
+ list_splice(&tmp_list, &wdata_list);
+
+ kref_put(&wdata->refcount,
+ cifs_uncached_writedata_release);
+ goto restart_loop;
+ }
+ }
+ list_del_init(&wdata->list);
+ kref_put(&wdata->refcount, cifs_uncached_writedata_release);
+ }
+
+ if (unlikely(!total_written))
+ return rc;
+
+ iocb->ki_pos += total_written;
+ set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(file_inode(file))->flags);
+ cifs_stats_bytes_written(tcon, total_written);
+ return total_written;
+}
+
+static ssize_t
+cifs_writev(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
+ struct inode *inode = file->f_mapping->host;
+ struct cifsInodeInfo *cinode = CIFS_I(inode);
+ struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
+ ssize_t rc;
+
+ /*
+ * We need to hold the sem to be sure nobody modifies lock list
+ * with a brlock that prevents writing.
+ */
+ down_read(&cinode->lock_sem);
+ mutex_lock(&inode->i_mutex);
+
+ rc = generic_write_checks(iocb, from);
+ if (rc <= 0)
+ goto out;
+
+ if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(from),
+ server->vals->exclusive_lock_type, NULL,
+ CIFS_WRITE_OP))
+ rc = __generic_file_write_iter(iocb, from);
+ else
+ rc = -EACCES;
+out:
+ mutex_unlock(&inode->i_mutex);
+
+ if (rc > 0) {
+ ssize_t err = generic_write_sync(file, iocb->ki_pos - rc, rc);
+ if (err < 0)
+ rc = err;
+ }
+ up_read(&cinode->lock_sem);
+ return rc;
+}
+
+ssize_t
+cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct cifsInodeInfo *cinode = CIFS_I(inode);
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct cifsFileInfo *cfile = (struct cifsFileInfo *)
+ iocb->ki_filp->private_data;
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ ssize_t written;
+
+ written = cifs_get_writer(cinode);
+ if (written)
+ return written;
+
+ if (CIFS_CACHE_WRITE(cinode)) {
+ if (cap_unix(tcon->ses) &&
+ (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))
+ && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0)) {
+ written = generic_file_write_iter(iocb, from);
+ goto out;
+ }
+ written = cifs_writev(iocb, from);
+ goto out;
+ }
+ /*
+ * For non-oplocked files 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.
+ */
+ written = cifs_user_writev(iocb, from);
+ if (written > 0 && CIFS_CACHE_READ(cinode)) {
+ /*
+ * Windows 7 server can delay breaking level2 oplock if a write
+ * request comes - break it on the client to prevent reading
+ * an old data.
+ */
+ cifs_zap_mapping(inode);
+ cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n",
+ inode);
+ cinode->oplock = 0;
+ }
+out:
+ cifs_put_writer(cinode);
+ return written;
+}
+
+static struct cifs_readdata *
+cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete)
+{
+ struct cifs_readdata *rdata;
+
+ rdata = kzalloc(sizeof(*rdata) + (sizeof(struct page *) * nr_pages),
+ GFP_KERNEL);
+ if (rdata != NULL) {
+ kref_init(&rdata->refcount);
+ INIT_LIST_HEAD(&rdata->list);
+ init_completion(&rdata->done);
+ INIT_WORK(&rdata->work, complete);
+ }
+
+ return rdata;
+}
+
+void
+cifs_readdata_release(struct kref *refcount)
+{
+ struct cifs_readdata *rdata = container_of(refcount,
+ struct cifs_readdata, refcount);
+
+ if (rdata->cfile)
+ cifsFileInfo_put(rdata->cfile);
+
+ kfree(rdata);
+}
+
+static int
+cifs_read_allocate_pages(struct cifs_readdata *rdata, unsigned int nr_pages)
+{
+ int rc = 0;
+ struct page *page;
+ unsigned int i;
+
+ for (i = 0; i < nr_pages; i++) {
+ page = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
+ if (!page) {
+ rc = -ENOMEM;
+ break;
+ }
+ rdata->pages[i] = page;
+ }
+
+ if (rc) {
+ for (i = 0; i < nr_pages; i++) {
+ put_page(rdata->pages[i]);
+ rdata->pages[i] = NULL;
+ }
+ }
+ return rc;
+}
+
+static void
+cifs_uncached_readdata_release(struct kref *refcount)
+{
+ struct cifs_readdata *rdata = container_of(refcount,
+ struct cifs_readdata, refcount);
+ unsigned int i;
+
+ for (i = 0; i < rdata->nr_pages; i++) {
+ put_page(rdata->pages[i]);
+ rdata->pages[i] = NULL;
+ }
+ cifs_readdata_release(refcount);
+}
+
+/**
+ * cifs_readdata_to_iov - copy data from pages in response to an iovec
+ * @rdata: the readdata response with list of pages holding data
+ * @iter: destination for our data
+ *
+ * This function copies data from a list of pages in a readdata response into
+ * an array of iovecs. It will first calculate where the data should go
+ * based on the info in the readdata and then copy the data into that spot.
+ */
+static int
+cifs_readdata_to_iov(struct cifs_readdata *rdata, struct iov_iter *iter)
+{
+ size_t remaining = rdata->got_bytes;
+ unsigned int i;
+
+ for (i = 0; i < rdata->nr_pages; i++) {
+ struct page *page = rdata->pages[i];
+ size_t copy = min_t(size_t, remaining, PAGE_SIZE);
+ size_t written = copy_page_to_iter(page, 0, copy, iter);
+ remaining -= written;
+ if (written < copy && iov_iter_count(iter) > 0)
+ break;
+ }
+ return remaining ? -EFAULT : 0;
+}
+
+static void
+cifs_uncached_readv_complete(struct work_struct *work)
+{
+ struct cifs_readdata *rdata = container_of(work,
+ struct cifs_readdata, work);
+
+ complete(&rdata->done);
+ kref_put(&rdata->refcount, cifs_uncached_readdata_release);
+}
+
+static int
+cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
+ struct cifs_readdata *rdata, unsigned int len)
+{
+ int result = 0;
+ unsigned int i;
+ unsigned int nr_pages = rdata->nr_pages;
+ struct kvec iov;
+
+ rdata->got_bytes = 0;
+ rdata->tailsz = PAGE_SIZE;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = rdata->pages[i];
+
+ if (len >= PAGE_SIZE) {
+ /* enough data to fill the page */
+ iov.iov_base = kmap(page);
+ iov.iov_len = PAGE_SIZE;
+ cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
+ i, iov.iov_base, iov.iov_len);
+ len -= PAGE_SIZE;
+ } else if (len > 0) {
+ /* enough for partial page, fill and zero the rest */
+ iov.iov_base = kmap(page);
+ iov.iov_len = len;
+ cifs_dbg(FYI, "%u: iov_base=%p iov_len=%zu\n",
+ i, iov.iov_base, iov.iov_len);
+ memset(iov.iov_base + len, '\0', PAGE_SIZE - len);
+ rdata->tailsz = len;
+ len = 0;
+ } else {
+ /* no need to hold page hostage */
+ rdata->pages[i] = NULL;
+ rdata->nr_pages--;
+ put_page(page);
+ continue;
+ }
+
+ result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
+ kunmap(page);
+ if (result < 0)
+ break;
+
+ rdata->got_bytes += result;
+ }
+
+ return rdata->got_bytes > 0 && result != -ECONNABORTED ?
+ rdata->got_bytes : result;
+}
+
+static int
+cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
+ struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
+{
+ struct cifs_readdata *rdata;
+ unsigned int npages, rsize, credits;
+ size_t cur_len;
+ int rc;
+ pid_t pid;
+ struct TCP_Server_Info *server;
+
+ server = tlink_tcon(open_file->tlink)->ses->server;
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
+ pid = open_file->pid;
+ else
+ pid = current->tgid;
+
+ do {
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
+ &rsize, &credits);
+ if (rc)
+ break;
+
+ cur_len = min_t(const size_t, len, rsize);
+ npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
+
+ /* allocate a readdata struct */
+ rdata = cifs_readdata_alloc(npages,
+ cifs_uncached_readv_complete);
+ if (!rdata) {
+ add_credits_and_wake_if(server, credits, 0);
+ rc = -ENOMEM;
+ break;
+ }
+
+ rc = cifs_read_allocate_pages(rdata, npages);
+ if (rc)
+ goto error;
+
+ rdata->cfile = cifsFileInfo_get(open_file);
+ rdata->nr_pages = npages;
+ rdata->offset = offset;
+ rdata->bytes = cur_len;
+ rdata->pid = pid;
+ rdata->pagesz = PAGE_SIZE;
+ rdata->read_into_pages = cifs_uncached_read_into_pages;
+ rdata->credits = credits;
+
+ if (!rdata->cfile->invalidHandle ||
+ !cifs_reopen_file(rdata->cfile, true))
+ rc = server->ops->async_readv(rdata);
+error:
+ if (rc) {
+ add_credits_and_wake_if(server, rdata->credits, 0);
+ kref_put(&rdata->refcount,
+ cifs_uncached_readdata_release);
+ if (rc == -EAGAIN)
+ continue;
+ break;
+ }
+
+ list_add_tail(&rdata->list, rdata_list);
+ offset += cur_len;
+ len -= cur_len;
+ } while (len > 0);
+
+ return rc;
+}
+
+ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ ssize_t rc;
+ size_t len;
+ ssize_t total_read = 0;
+ loff_t offset = iocb->ki_pos;
+ struct cifs_sb_info *cifs_sb;
+ struct cifs_tcon *tcon;
+ struct cifsFileInfo *open_file;
+ struct cifs_readdata *rdata, *tmp;
+ struct list_head rdata_list;
+
+ len = iov_iter_count(to);
+ if (!len)
+ return 0;
+
+ INIT_LIST_HEAD(&rdata_list);
+ cifs_sb = CIFS_FILE_SB(file);
+ open_file = file->private_data;
+ tcon = tlink_tcon(open_file->tlink);
+
+ if (!tcon->ses->server->ops->async_readv)
+ return -ENOSYS;
+
+ if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+ cifs_dbg(FYI, "attempting read on write only file instance\n");
+
+ rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
+
+ /* if at least one read request send succeeded, then reset rc */
+ if (!list_empty(&rdata_list))
+ rc = 0;
+
+ len = iov_iter_count(to);
+ /* the loop below should proceed in the order of increasing offsets */
+again:
+ list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
+ if (!rc) {
+ /* FIXME: freezable sleep too? */
+ rc = wait_for_completion_killable(&rdata->done);
+ if (rc)
+ rc = -EINTR;
+ else if (rdata->result == -EAGAIN) {
+ /* resend call if it's a retryable error */
+ struct list_head tmp_list;
+ unsigned int got_bytes = rdata->got_bytes;
+
+ list_del_init(&rdata->list);
+ INIT_LIST_HEAD(&tmp_list);
+
+ /*
+ * Got a part of data and then reconnect has
+ * happened -- fill the buffer and continue
+ * reading.
+ */
+ if (got_bytes && got_bytes < rdata->bytes) {
+ rc = cifs_readdata_to_iov(rdata, to);
+ if (rc) {
+ kref_put(&rdata->refcount,
+ cifs_uncached_readdata_release);
+ continue;
+ }
+ }
+
+ rc = cifs_send_async_read(
+ rdata->offset + got_bytes,
+ rdata->bytes - got_bytes,
+ rdata->cfile, cifs_sb,
+ &tmp_list);
+
+ list_splice(&tmp_list, &rdata_list);
+
+ kref_put(&rdata->refcount,
+ cifs_uncached_readdata_release);
+ goto again;
+ } else if (rdata->result)
+ rc = rdata->result;
+ else
+ rc = cifs_readdata_to_iov(rdata, to);
+
+ /* if there was a short read -- discard anything left */
+ if (rdata->got_bytes && rdata->got_bytes < rdata->bytes)
+ rc = -ENODATA;
+ }
+ list_del_init(&rdata->list);
+ kref_put(&rdata->refcount, cifs_uncached_readdata_release);
+ }
+
+ total_read = len - iov_iter_count(to);
+
+ cifs_stats_bytes_read(tcon, total_read);
+
+ /* mask nodata case */
+ if (rc == -ENODATA)
+ rc = 0;
+
+ if (total_read) {
+ iocb->ki_pos += total_read;
+ return total_read;
+ }
+ return rc;
+}
+
+ssize_t
+cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ struct cifsInodeInfo *cinode = CIFS_I(inode);
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct cifsFileInfo *cfile = (struct cifsFileInfo *)
+ iocb->ki_filp->private_data;
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ int rc = -EACCES;
+
+ /*
+ * 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.
+ */
+ if (!CIFS_CACHE_READ(cinode))
+ return cifs_user_readv(iocb, to);
+
+ if (cap_unix(tcon->ses) &&
+ (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
+ ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
+ return generic_file_read_iter(iocb, to);
+
+ /*
+ * We need to hold the sem to be sure nobody modifies lock list
+ * with a brlock that prevents reading.
+ */
+ down_read(&cinode->lock_sem);
+ if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
+ tcon->ses->server->vals->shared_lock_type,
+ NULL, CIFS_READ_OP))
+ rc = generic_file_read_iter(iocb, to);
+ up_read(&cinode->lock_sem);
+ return rc;
+}
+
+static ssize_t
+cifs_read(struct file *file, char *read_data, size_t read_size, loff_t *offset)
+{
+ 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 *tcon;
+ struct TCP_Server_Info *server;
+ unsigned int xid;
+ char *cur_offset;
+ struct cifsFileInfo *open_file;
+ struct cifs_io_parms io_parms;
+ int buf_type = CIFS_NO_BUFFER;
+ __u32 pid;
+
+ xid = get_xid();
+ cifs_sb = CIFS_FILE_SB(file);
+
+ /* 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;
+ free_xid(xid);
+ return rc;
+ }
+ open_file = file->private_data;
+ tcon = tlink_tcon(open_file->tlink);
+ server = tcon->ses->server;
+
+ if (!server->ops->sync_read) {
+ free_xid(xid);
+ return -ENOSYS;
+ }
+
+ 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)
+ cifs_dbg(FYI, "attempting read on write only file instance\n");
+
+ for (total_read = 0, cur_offset = read_data; read_size > total_read;
+ total_read += bytes_read, cur_offset += bytes_read) {
+ do {
+ 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 ((tcon->ses) && !(tcon->ses->capabilities &
+ tcon->ses->server->vals->cap_large_files)) {
+ current_read_size = min_t(uint,
+ current_read_size, CIFSMaxBufSize);
+ }
+ if (open_file->invalidHandle) {
+ rc = cifs_reopen_file(open_file, true);
+ if (rc != 0)
+ break;
+ }
+ io_parms.pid = pid;
+ io_parms.tcon = tcon;
+ io_parms.offset = *offset;
+ io_parms.length = current_read_size;
+ rc = server->ops->sync_read(xid, &open_file->fid, &io_parms,
+ &bytes_read, &cur_offset,
+ &buf_type);
+ } while (rc == -EAGAIN);
+
+ if (rc || (bytes_read == 0)) {
+ if (total_read) {
+ break;
+ } else {
+ free_xid(xid);
+ return rc;
+ }
+ } else {
+ cifs_stats_bytes_read(tcon, total_read);
+ *offset += bytes_read;
+ }
+ }
+ free_xid(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,
+ .map_pages = filemap_map_pages,
+ .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_inode(file);
+
+ xid = get_xid();
+
+ if (!CIFS_CACHE_READ(CIFS_I(inode))) {
+ rc = cifs_zap_mapping(inode);
+ if (rc)
+ return rc;
+ }
+
+ rc = generic_file_mmap(file, vma);
+ if (rc == 0)
+ vma->vm_ops = &cifs_file_vm_ops;
+ free_xid(xid);
+ return rc;
+}
+
+int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ int rc, xid;
+
+ xid = get_xid();
+ rc = cifs_revalidate_file(file);
+ if (rc) {
+ cifs_dbg(FYI, "Validation prior to mmap failed, error=%d\n",
+ rc);
+ free_xid(xid);
+ return rc;
+ }
+ rc = generic_file_mmap(file, vma);
+ if (rc == 0)
+ vma->vm_ops = &cifs_file_vm_ops;
+ free_xid(xid);
+ return rc;
+}
+
+static void
+cifs_readv_complete(struct work_struct *work)
+{
+ unsigned int i, got_bytes;
+ struct cifs_readdata *rdata = container_of(work,
+ struct cifs_readdata, work);
+
+ got_bytes = rdata->got_bytes;
+ for (i = 0; i < rdata->nr_pages; i++) {
+ struct page *page = rdata->pages[i];
+
+ lru_cache_add_file(page);
+
+ if (rdata->result == 0 ||
+ (rdata->result == -EAGAIN && got_bytes)) {
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ }
+
+ unlock_page(page);
+
+ if (rdata->result == 0 ||
+ (rdata->result == -EAGAIN && got_bytes))
+ cifs_readpage_to_fscache(rdata->mapping->host, page);
+
+ got_bytes -= min_t(unsigned int, PAGE_CACHE_SIZE, got_bytes);
+
+ page_cache_release(page);
+ rdata->pages[i] = NULL;
+ }
+ kref_put(&rdata->refcount, cifs_readdata_release);
+}
+
+static int
+cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
+ struct cifs_readdata *rdata, unsigned int len)
+{
+ int result = 0;
+ unsigned int i;
+ u64 eof;
+ pgoff_t eof_index;
+ unsigned int nr_pages = rdata->nr_pages;
+ struct kvec iov;
+
+ /* determine the eof that the server (probably) has */
+ eof = CIFS_I(rdata->mapping->host)->server_eof;
+ eof_index = eof ? (eof - 1) >> PAGE_CACHE_SHIFT : 0;
+ cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
+
+ rdata->got_bytes = 0;
+ rdata->tailsz = PAGE_CACHE_SIZE;
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page = rdata->pages[i];
+
+ if (len >= PAGE_CACHE_SIZE) {
+ /* enough data to fill the page */
+ iov.iov_base = kmap(page);
+ iov.iov_len = PAGE_CACHE_SIZE;
+ cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
+ i, page->index, iov.iov_base, iov.iov_len);
+ len -= PAGE_CACHE_SIZE;
+ } else if (len > 0) {
+ /* enough for partial page, fill and zero the rest */
+ iov.iov_base = kmap(page);
+ iov.iov_len = len;
+ cifs_dbg(FYI, "%u: idx=%lu iov_base=%p iov_len=%zu\n",
+ i, page->index, iov.iov_base, iov.iov_len);
+ memset(iov.iov_base + len,
+ '\0', PAGE_CACHE_SIZE - len);
+ rdata->tailsz = len;
+ len = 0;
+ } else if (page->index > eof_index) {
+ /*
+ * The VFS will not try to do readahead past the
+ * i_size, but it's possible that we have outstanding
+ * writes with gaps in the middle and the i_size hasn't
+ * caught up yet. Populate those with zeroed out pages
+ * to prevent the VFS from repeatedly attempting to
+ * fill them until the writes are flushed.
+ */
+ zero_user(page, 0, PAGE_CACHE_SIZE);
+ lru_cache_add_file(page);
+ flush_dcache_page(page);
+ SetPageUptodate(page);
+ unlock_page(page);
+ page_cache_release(page);
+ rdata->pages[i] = NULL;
+ rdata->nr_pages--;
+ continue;
+ } else {
+ /* no need to hold page hostage */
+ lru_cache_add_file(page);
+ unlock_page(page);
+ page_cache_release(page);
+ rdata->pages[i] = NULL;
+ rdata->nr_pages--;
+ continue;
+ }
+
+ result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
+ kunmap(page);
+ if (result < 0)
+ break;
+
+ rdata->got_bytes += result;
+ }
+
+ return rdata->got_bytes > 0 && result != -ECONNABORTED ?
+ rdata->got_bytes : result;
+}
+
+static int
+readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
+ unsigned int rsize, struct list_head *tmplist,
+ unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
+{
+ struct page *page, *tpage;
+ unsigned int expected_index;
+ int rc;
+
+ INIT_LIST_HEAD(tmplist);
+
+ 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);
+ return rc;
+ }
+
+ /* move first page to the tmplist */
+ *offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
+ *bytes = PAGE_CACHE_SIZE;
+ *nr_pages = 1;
+ 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)++;
+ }
+ 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_FILE_SB(file);
+ struct TCP_Server_Info *server;
+ pid_t pid;
+
+ /*
+ * Reads as many pages as possible from fscache. Returns -ENOBUFS
+ * immediately if the cookie is negative
+ *
+ * After this point, every page in the list might have PG_fscache set,
+ * so we will need to clean that up off of every page we don't use.
+ */
+ 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;
+ server = tlink_tcon(open_file->tlink)->ses->server;
+
+ cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
+ __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 i, nr_pages, bytes, rsize;
+ loff_t offset;
+ struct page *page, *tpage;
+ struct cifs_readdata *rdata;
+ unsigned credits;
+
+ rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
+ &rsize, &credits);
+ if (rc)
+ break;
+
+ /*
+ * 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)) {
+ add_credits_and_wake_if(server, credits, 0);
+ return 0;
+ }
+
+ rc = readpages_get_pages(mapping, page_list, rsize, &tmplist,
+ &nr_pages, &offset, &bytes);
+ if (rc) {
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
+ 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;
+ add_credits_and_wake_if(server, credits, 0);
+ break;
+ }
+
+ rdata->cfile = cifsFileInfo_get(open_file);
+ rdata->mapping = mapping;
+ rdata->offset = offset;
+ rdata->bytes = bytes;
+ rdata->pid = pid;
+ rdata->pagesz = PAGE_CACHE_SIZE;
+ rdata->read_into_pages = cifs_readpages_read_into_pages;
+ rdata->credits = credits;
+
+ list_for_each_entry_safe(page, tpage, &tmplist, lru) {
+ list_del(&page->lru);
+ rdata->pages[rdata->nr_pages++] = page;
+ }
+
+ if (!rdata->cfile->invalidHandle ||
+ !cifs_reopen_file(rdata->cfile, true))
+ rc = server->ops->async_readv(rdata);
+ if (rc) {
+ add_credits_and_wake_if(server, rdata->credits, 0);
+ for (i = 0; i < rdata->nr_pages; i++) {
+ page = rdata->pages[i];
+ lru_cache_add_file(page);
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ /* Fallback to the readpage in error/reconnect cases */
+ kref_put(&rdata->refcount, cifs_readdata_release);
+ break;
+ }
+
+ kref_put(&rdata->refcount, cifs_readdata_release);
+ }
+
+ /* Any pages that have been shown to fscache but didn't get added to
+ * the pagecache must be uncached before they get returned to the
+ * allocator.
+ */
+ cifs_fscache_readpages_cancel(mapping->host, page_list);
+ return rc;
+}
+
+/*
+ * cifs_readpage_worker must be called with the page pinned
+ */
+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_inode(file), page);
+ if (rc == 0)
+ goto read_complete;
+
+ 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
+ cifs_dbg(FYI, "Bytes read %d\n", rc);
+
+ file_inode(file)->i_atime =
+ current_fs_time(file_inode(file)->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_inode(file), page);
+
+ rc = 0;
+
+io_error:
+ kunmap(page);
+ unlock_page(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;
+ unsigned int xid;
+
+ xid = get_xid();
+
+ if (file->private_data == NULL) {
+ rc = -EBADF;
+ free_xid(xid);
+ return rc;
+ }
+
+ cifs_dbg(FYI, "readpage %p at offset %d 0x%x\n",
+ page, (int)offset, (int)offset);
+
+ rc = cifs_readpage_worker(file, page, &offset);
+
+ free_xid(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)
+{
+ int oncethru = 0;
+ 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;
+
+ cifs_dbg(FYI, "write_begin from %lld len %d\n", (long long)pos, len);
+
+start:
+ 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_CACHE_READ(CIFS_I(mapping->host))) {
+ 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 && !oncethru) {
+ /*
+ * 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);
+ page_cache_release(page);
+ oncethru = 1;
+ goto 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 int offset,
+ unsigned int length)
+{
+ struct cifsInodeInfo *cifsi = CIFS_I(page->mapping->host);
+
+ if (offset == 0 && length == PAGE_CACHE_SIZE)
+ 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,
+ };
+
+ cifs_dbg(FYI, "Launder page: %p\n", 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 = d_inode(cfile->dentry);
+ struct cifsInodeInfo *cinode = CIFS_I(inode);
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ struct TCP_Server_Info *server = tcon->ses->server;
+ int rc = 0;
+
+ wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS,
+ TASK_UNINTERRUPTIBLE);
+
+ server->ops->downgrade_oplock(server, cinode,
+ test_bit(CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2, &cinode->flags));
+
+ if (!CIFS_CACHE_WRITE(cinode) && CIFS_CACHE_READ(cinode) &&
+ cifs_has_mand_locks(cinode)) {
+ cifs_dbg(FYI, "Reset oplock to None for inode=%p due to mand locks\n",
+ inode);
+ cinode->oplock = 0;
+ }
+
+ if (inode && S_ISREG(inode->i_mode)) {
+ if (CIFS_CACHE_READ(cinode))
+ break_lease(inode, O_RDONLY);
+ else
+ break_lease(inode, O_WRONLY);
+ rc = filemap_fdatawrite(inode->i_mapping);
+ if (!CIFS_CACHE_READ(cinode)) {
+ rc = filemap_fdatawait(inode->i_mapping);
+ mapping_set_error(inode->i_mapping, rc);
+ cifs_zap_mapping(inode);
+ }
+ cifs_dbg(FYI, "Oplock flush inode %p rc %d\n", inode, rc);
+ }
+
+ rc = cifs_push_locks(cfile);
+ if (rc)
+ cifs_dbg(VFS, "Push locks rc = %d\n", 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 = tcon->ses->server->ops->oplock_response(tcon, &cfile->fid,
+ cinode);
+ cifs_dbg(FYI, "Oplock release rc = %d\n", rc);
+ }
+ cifs_done_oplock_break(cinode);
+}
+
+/*
+ * The presence of cifs_direct_io() in the address space ops vector
+ * allowes open() O_DIRECT flags which would have failed otherwise.
+ *
+ * In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
+ * so this method should never be called.
+ *
+ * Direct IO is not yet supported in the cached mode.
+ */
+static ssize_t
+cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+{
+ /*
+ * FIXME
+ * Eventually need to support direct IO for non forcedirectio mounts
+ */
+ return -EINVAL;
+}
+
+
+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,
+ .direct_IO = cifs_direct_io,
+ .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,
+};
Code Review / kvmfornfv.git / blobdiff