diff options
Diffstat (limited to 'fs/cifs/file.c')
| -rw-r--r-- | fs/cifs/file.c | 4292 |
1 files changed, 4292 insertions, 0 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c new file mode 100644 index 000000000..7b482489b --- /dev/null +++ b/fs/cifs/file.c @@ -0,0 +1,4292 @@ +/* + * 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" +#include "smbdirect.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_revalidate_mapping(*pinode); + 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; + + /* O_SYNC also has bit for O_DSYNC so following check picks up either */ + if (f_flags & O_SYNC) + create_options |= CREATE_WRITE_THROUGH; + + if (f_flags & O_DIRECT) + create_options |= CREATE_NO_BUFFER; + + 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); + + if (rc) { + server->ops->close(xid, tcon, fid); + if (rc == -ESTALE) + rc = -EOPENSTALE; + } + +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; +} + +void +cifs_down_write(struct rw_semaphore *sem) +{ + while (!down_write_trylock(sem)) + msleep(10); +} + +struct cifsFileInfo * +cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, + struct tcon_link *tlink, __u32 oplock) +{ + struct dentry *dentry = file_dentry(file); + 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; + + 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); + spin_lock_init(&cfile->file_info_lock); + + 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; + } + + cifs_down_write(&cinode->lock_sem); + list_add(&fdlocks->llist, &cinode->llist); + up_write(&cinode->lock_sem); + + spin_lock(&tcon->open_file_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*/ + spin_lock(&cinode->open_file_lock); + if (file->f_mode & FMODE_READ) + list_add(&cfile->flist, &cinode->openFileList); + else + list_add_tail(&cfile->flist, &cinode->openFileList); + spin_unlock(&cinode->open_file_lock); + spin_unlock(&tcon->open_file_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->file_info_lock); + cifsFileInfo_get_locked(cifs_file); + spin_unlock(&cifs_file->file_info_lock); + return cifs_file; +} + +/** + * cifsFileInfo_put - release a reference of file priv data + * + * Always potentially wait for oplock handler. See _cifsFileInfo_put(). + */ +void cifsFileInfo_put(struct cifsFileInfo *cifs_file) +{ + _cifsFileInfo_put(cifs_file, true); +} + +/** + * _cifsFileInfo_put - release a reference of file priv data + * + * This may involve closing the filehandle @cifs_file out on the + * server. Must be called without holding tcon->open_file_lock and + * cifs_file->file_info_lock. + * + * If @wait_for_oplock_handler is true and we are releasing the last + * reference, wait for any running oplock break handler of the file + * and cancel any pending one. If calling this function from the + * oplock break handler, you need to pass false. + * + */ +void _cifsFileInfo_put(struct cifsFileInfo *cifs_file, bool wait_oplock_handler) +{ + 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(&tcon->open_file_lock); + spin_lock(&cifsi->open_file_lock); + spin_lock(&cifs_file->file_info_lock); + if (--cifs_file->count > 0) { + spin_unlock(&cifs_file->file_info_lock); + spin_unlock(&cifsi->open_file_lock); + spin_unlock(&tcon->open_file_lock); + return; + } + spin_unlock(&cifs_file->file_info_lock); + + 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(&cifsi->open_file_lock); + spin_unlock(&tcon->open_file_lock); + + oplock_break_cancelled = wait_oplock_handler ? + cancel_work_sync(&cifs_file->oplock_break) : false; + + 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. + */ + cifs_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_dentry(file)); + 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_nested(&cinode->lock_sem, SINGLE_DEPTH_NESTING); + 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; + + /* O_SYNC also has bit for O_DSYNC so following check picks up either */ + if (cfile->f_flags & O_SYNC) + create_options |= CREATE_WRITE_THROUGH; + + if (cfile->f_flags & O_DIRECT) + create_options |= CREATE_NO_BUFFER; + + 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); + if (!is_interrupt_error(rc)) + 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. + */ + + /* + * 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; + } + + 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; +} + +void +cifs_reopen_persistent_handles(struct cifs_tcon *tcon) +{ + struct cifsFileInfo *open_file; + struct list_head *tmp; + struct list_head *tmp1; + struct list_head tmp_list; + + if (!tcon->use_persistent || !tcon->need_reopen_files) + return; + + tcon->need_reopen_files = false; + + cifs_dbg(FYI, "Reopen persistent handles"); + INIT_LIST_HEAD(&tmp_list); + + /* list all files open on tree connection, reopen resilient handles */ + spin_lock(&tcon->open_file_lock); + list_for_each(tmp, &tcon->openFileList) { + open_file = list_entry(tmp, struct cifsFileInfo, tlist); + if (!open_file->invalidHandle) + continue; + cifsFileInfo_get(open_file); + list_add_tail(&open_file->rlist, &tmp_list); + } + spin_unlock(&tcon->open_file_lock); + + list_for_each_safe(tmp, tmp1, &tmp_list) { + open_file = list_entry(tmp, struct cifsFileInfo, rlist); + if (cifs_reopen_file(open_file, false /* do not flush */)) + tcon->need_reopen_files = true; + list_del_init(&open_file->rlist); + cifsFileInfo_put(open_file); + } +} + +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(&cfile->file_info_lock); + if (server->ops->dir_needs_close(cfile)) { + cfile->invalidHandle = true; + spin_unlock(&cfile->file_info_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(&cfile->file_info_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)); + cifs_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; + cifs_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; + cifs_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: + cifs_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; + static const 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 before using. + */ + max_buf = tcon->ses->server->maxBuf; + if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) { + free_xid(xid); + return -EINVAL; + } + + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); + 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; +} + +static __u32 +hash_lockowner(fl_owner_t owner) +{ + return cifs_lock_secret ^ hash32_ptr((const void *)owner); +} + +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 = hash_lockowner(flock->fl_owner); + 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 */ + cifs_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, + hash_lockowner(flock->fl_owner), + 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; + static const 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 before using. + */ + max_buf = tcon->ses->server->maxBuf; + if (max_buf < (sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE))) + return -EINVAL; + + BUILD_BUG_ON(sizeof(struct smb_hdr) + sizeof(LOCKING_ANDX_RANGE) > + PAGE_SIZE); + max_buf = min_t(unsigned int, max_buf - sizeof(struct smb_hdr), + PAGE_SIZE); + 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; + + cifs_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, + hash_lockowner(flock->fl_owner), + 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) { + /* + * If this is a request to remove all locks because we + * are closing the file, it doesn't matter if the + * unlocking failed as both cifs.ko and the SMB server + * remove the lock on file close + */ + if (rc) { + cifs_dbg(VFS, "%s failed rc=%d\n", __func__, rc); + if (!(flock->fl_flags & FL_CLOSE)) + return rc; + } + rc = locks_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_inode->open_file_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(open_file); + spin_unlock(&cifs_inode->open_file_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_inode->open_file_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_inode->open_file_lock); +refind_writable: + if (refind > MAX_REOPEN_ATT) { + spin_unlock(&cifs_inode->open_file_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(open_file); + spin_unlock(&cifs_inode->open_file_lock); + return open_file; + } else { + if (!inv_file) + inv_file = open_file; + } + } + } + /* couldn't find useable FH with same pid, try any available */ + if (!any_available) { + any_available = true; + goto refind_writable; + } + + if (inv_file) { + any_available = false; + cifsFileInfo_get(inv_file); + } + + spin_unlock(&cifs_inode->open_file_lock); + + if (inv_file) { + rc = cifs_reopen_file(inv_file, false); + if (!rc) + return inv_file; + else { + spin_lock(&cifs_inode->open_file_lock); + list_move_tail(&inv_file->flist, + &cifs_inode->openFileList); + spin_unlock(&cifs_inode->open_file_lock); + cifsFileInfo_put(inv_file); + ++refind; + inv_file = NULL; + spin_lock(&cifs_inode->open_file_lock); + 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_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_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_time(inode); + 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) +{ + struct cifs_writedata *wdata; + + wdata = cifs_writedata_alloc((unsigned int)tofind, + cifs_writev_complete); + if (!wdata) + return NULL; + + *found_pages = find_get_pages_range_tag(mapping, index, end, + PAGECACHE_TAG_DIRTY, tofind, wdata->pages); + 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 the i_pages lock nor the + * page lock: 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++) { + put_page(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_SIZE; + wdata->tailsz = min(i_size_read(mapping->host) - + page_offset(wdata->pages[nr_pages - 1]), + (loff_t)PAGE_SIZE); + wdata->bytes = ((nr_pages - 1) * PAGE_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; + int saved_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_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_SHIFT; + end = wbc->range_end >> PAGE_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 != 0) { + done = true; + break; + } + + tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1; + + wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index, + &found_pages); + if (!wdata) { + rc = -ENOMEM; + done = true; + 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 (is_retryable_error(rc)) + redirty_page_for_writepage(wbc, + wdata->pages[i]); + else + SetPageError(wdata->pages[i]); + end_page_writeback(wdata->pages[i]); + put_page(wdata->pages[i]); + } + if (!is_retryable_error(rc)) + 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; + } + + /* Return immediately if we received a signal during writing */ + if (is_interrupt_error(rc)) { + done = true; + break; + } + + if (rc != 0 && saved_rc == 0) + saved_rc = rc; + + 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 (saved_rc != 0) + rc = saved_rc; + + 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 */ + get_page(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_SIZE); + if (is_retryable_error(rc)) { + if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) + goto retry_write; + redirty_page_for_writepage(wbc, page); + } else if (rc != 0) { + SetPageError(page); + mapping_set_error(page->mapping, rc); + } else { + SetPageUptodate(page); + } + end_page_writeback(page); + put_page(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_SIZE) + SetPageUptodate(page); + + if (!PageUptodate(page)) { + char *page_data; + unsigned offset = pos & (PAGE_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); + put_page(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 = file_write_and_wait_range(file, start, end); + if (rc) + return rc; + inode_lock(inode); + + 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); + inode_unlock(inode); + 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 = file_write_and_wait_range(file, start, end); + if (rc) + return rc; + inode_lock(inode); + + 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); + inode_unlock(inode); + 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); + + kref_put(&wdata->ctx->refcount, cifs_aio_ctx_release); + for (i = 0; i < wdata->nr_pages; i++) + put_page(wdata->pages[i]); + cifs_writedata_release(refcount); +} + +static void collect_uncached_write_data(struct cifs_aio_ctx *ctx); + +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); + collect_uncached_write_data(wdata->ctx); + /* the below call can possibly free the last ref to aio ctx */ + 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, + struct cifs_aio_ctx *ctx) +{ + int rc = 0; + size_t cur_len; + unsigned long nr_pages, num_pages, i; + struct cifs_writedata *wdata; + struct iov_iter saved_from = *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; + + 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; + wdata->ctx = ctx; + kref_get(&ctx->refcount); + + if (!wdata->cfile->invalidHandle || + !(rc = 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) { + *from = saved_from; + 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; +} + +static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) +{ + struct cifs_writedata *wdata, *tmp; + struct cifs_tcon *tcon; + struct cifs_sb_info *cifs_sb; + struct dentry *dentry = ctx->cfile->dentry; + unsigned int i; + int rc; + + tcon = tlink_tcon(ctx->cfile->tlink); + cifs_sb = CIFS_SB(dentry->d_sb); + + mutex_lock(&ctx->aio_mutex); + + if (list_empty(&ctx->list)) { + mutex_unlock(&ctx->aio_mutex); + return; + } + + rc = ctx->rc; + /* + * Wait for and collect replies for any successful sends in order of + * increasing offset. Once an error is hit, then return without waiting + * for any more replies. + */ +restart_loop: + list_for_each_entry_safe(wdata, tmp, &ctx->list, list) { + if (!rc) { + if (!try_wait_for_completion(&wdata->done)) { + mutex_unlock(&ctx->aio_mutex); + return; + } + + if (wdata->result) + rc = wdata->result; + else + ctx->total_len += wdata->bytes; + + /* resend call if it's a retryable error */ + if (rc == -EAGAIN) { + struct list_head tmp_list; + struct iov_iter tmp_from = ctx->iter; + + INIT_LIST_HEAD(&tmp_list); + list_del_init(&wdata->list); + + iov_iter_advance(&tmp_from, + wdata->offset - ctx->pos); + + rc = cifs_write_from_iter(wdata->offset, + wdata->bytes, &tmp_from, + ctx->cfile, cifs_sb, &tmp_list, + ctx); + + list_splice(&tmp_list, &ctx->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); + } + + for (i = 0; i < ctx->npages; i++) + put_page(ctx->bv[i].bv_page); + + cifs_stats_bytes_written(tcon, ctx->total_len); + set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags); + + ctx->rc = (rc == 0) ? ctx->total_len : rc; + + mutex_unlock(&ctx->aio_mutex); + + if (ctx->iocb && ctx->iocb->ki_complete) + ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0); + else + complete(&ctx->done); +} + +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 *cfile; + struct cifs_tcon *tcon; + struct cifs_sb_info *cifs_sb; + struct cifs_aio_ctx *ctx; + struct iov_iter saved_from = *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; + + cifs_sb = CIFS_FILE_SB(file); + cfile = file->private_data; + tcon = tlink_tcon(cfile->tlink); + + if (!tcon->ses->server->ops->async_writev) + return -ENOSYS; + + ctx = cifs_aio_ctx_alloc(); + if (!ctx) + return -ENOMEM; + + ctx->cfile = cifsFileInfo_get(cfile); + + if (!is_sync_kiocb(iocb)) + ctx->iocb = iocb; + + ctx->pos = iocb->ki_pos; + + rc = setup_aio_ctx_iter(ctx, from, WRITE); + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } + + /* grab a lock here due to read response handlers can access ctx */ + mutex_lock(&ctx->aio_mutex); + + rc = cifs_write_from_iter(iocb->ki_pos, ctx->len, &saved_from, + cfile, cifs_sb, &ctx->list, ctx); + + /* + * 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(&ctx->list)) + rc = 0; + + mutex_unlock(&ctx->aio_mutex); + + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } + + if (!is_sync_kiocb(iocb)) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return -EIOCBQUEUED; + } + + rc = wait_for_completion_killable(&ctx->done); + if (rc) { + mutex_lock(&ctx->aio_mutex); + ctx->rc = rc = -EINTR; + total_written = ctx->total_len; + mutex_unlock(&ctx->aio_mutex); + } else { + rc = ctx->rc; + total_written = ctx->total_len; + } + + kref_put(&ctx->refcount, cifs_aio_ctx_release); + + if (unlikely(!total_written)) + return rc; + + iocb->ki_pos += 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; + + inode_lock(inode); + /* + * We need to hold the sem to be sure nobody modifies lock list + * with a brlock that prevents writing. + */ + down_read(&cinode->lock_sem); + + 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: + up_read(&cinode->lock_sem); + inode_unlock(inode); + + if (rc > 0) + rc = generic_write_sync(iocb, rc); + 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 (CIFS_CACHE_READ(cinode)) { + /* + * We have read level caching and we have just sent a write + * request to the server thus making data in the cache stale. + * Zap the cache and set oplock/lease level to NONE to avoid + * reading stale data from the cache. All subsequent read + * operations will read new data from the server. + */ + cifs_zap_mapping(inode); + cifs_dbg(FYI, "Set Oplock/Lease to NONE for inode=%p after write\n", + inode); + cinode->oplock = 0; + } +out: + cifs_put_writer(cinode); + return written; +} + +static struct cifs_readdata * +cifs_readdata_direct_alloc(struct page **pages, work_func_t complete) +{ + struct cifs_readdata *rdata; + + rdata = kzalloc(sizeof(*rdata), GFP_KERNEL); + if (rdata != NULL) { + rdata->pages = pages; + kref_init(&rdata->refcount); + INIT_LIST_HEAD(&rdata->list); + init_completion(&rdata->done); + INIT_WORK(&rdata->work, complete); + } + + return rdata; +} + +static struct cifs_readdata * +cifs_readdata_alloc(unsigned int nr_pages, work_func_t complete) +{ + struct page **pages = + kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL); + struct cifs_readdata *ret = NULL; + + if (pages) { + ret = cifs_readdata_direct_alloc(pages, complete); + if (!ret) + kfree(pages); + } + + return ret; +} + +void +cifs_readdata_release(struct kref *refcount) +{ + struct cifs_readdata *rdata = container_of(refcount, + struct cifs_readdata, refcount); +#ifdef CONFIG_CIFS_SMB_DIRECT + if (rdata->mr) { + smbd_deregister_mr(rdata->mr); + rdata->mr = NULL; + } +#endif + if (rdata->cfile) + cifsFileInfo_put(rdata->cfile); + + kvfree(rdata->pages); + 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) { + unsigned int nr_page_failed = i; + + for (i = 0; i < nr_page_failed; 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; + + kref_put(&rdata->ctx->refcount, cifs_aio_ctx_release); + 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; + + if (unlikely(iter->type & ITER_PIPE)) { + void *addr = kmap_atomic(page); + + written = copy_to_iter(addr, copy, iter); + kunmap_atomic(addr); + } else + 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 collect_uncached_read_data(struct cifs_aio_ctx *ctx); + +static void +cifs_uncached_readv_complete(struct work_struct *work) +{ + struct cifs_readdata *rdata = container_of(work, + struct cifs_readdata, work); + + complete(&rdata->done); + collect_uncached_read_data(rdata->ctx); + /* the below call can possibly free the last ref to aio ctx */ + kref_put(&rdata->refcount, cifs_uncached_readdata_release); +} + +static int +uncached_fill_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, struct iov_iter *iter, + unsigned int len) +{ + int result = 0; + unsigned int i; + unsigned int nr_pages = rdata->nr_pages; + unsigned int page_offset = rdata->page_offset; + + rdata->got_bytes = 0; + rdata->tailsz = PAGE_SIZE; + for (i = 0; i < nr_pages; i++) { + struct page *page = rdata->pages[i]; + size_t n; + unsigned int segment_size = rdata->pagesz; + + if (i == 0) + segment_size -= page_offset; + else + page_offset = 0; + + + if (len <= 0) { + /* no need to hold page hostage */ + rdata->pages[i] = NULL; + rdata->nr_pages--; + put_page(page); + continue; + } + + n = len; + if (len >= segment_size) + /* enough data to fill the page */ + n = segment_size; + else + rdata->tailsz = len; + len -= n; + + if (iter) + result = copy_page_from_iter( + page, page_offset, n, iter); +#ifdef CONFIG_CIFS_SMB_DIRECT + else if (rdata->mr) + result = n; +#endif + else + result = cifs_read_page_from_socket( + server, page, page_offset, n); + if (result < 0) + break; + + rdata->got_bytes += result; + } + + return rdata->got_bytes > 0 && result != -ECONNABORTED ? + rdata->got_bytes : result; +} + +static int +cifs_uncached_read_into_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, unsigned int len) +{ + return uncached_fill_pages(server, rdata, NULL, len); +} + +static int +cifs_uncached_copy_into_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, + struct iov_iter *iter) +{ + return uncached_fill_pages(server, rdata, iter, iter->count); +} + +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_aio_ctx *ctx) +{ + 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->tailsz = PAGE_SIZE; + rdata->read_into_pages = cifs_uncached_read_into_pages; + rdata->copy_into_pages = cifs_uncached_copy_into_pages; + rdata->credits = credits; + rdata->ctx = ctx; + kref_get(&ctx->refcount); + + if (!rdata->cfile->invalidHandle || + !(rc = 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; +} + +static void +collect_uncached_read_data(struct cifs_aio_ctx *ctx) +{ + struct cifs_readdata *rdata, *tmp; + struct iov_iter *to = &ctx->iter; + struct cifs_sb_info *cifs_sb; + struct cifs_tcon *tcon; + unsigned int i; + int rc; + + tcon = tlink_tcon(ctx->cfile->tlink); + cifs_sb = CIFS_SB(ctx->cfile->dentry->d_sb); + + mutex_lock(&ctx->aio_mutex); + + if (list_empty(&ctx->list)) { + mutex_unlock(&ctx->aio_mutex); + return; + } + + rc = ctx->rc; + /* the loop below should proceed in the order of increasing offsets */ +again: + list_for_each_entry_safe(rdata, tmp, &ctx->list, list) { + if (!rc) { + if (!try_wait_for_completion(&rdata->done)) { + mutex_unlock(&ctx->aio_mutex); + return; + } + + 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, ctx); + + list_splice(&tmp_list, &ctx->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); + } + + for (i = 0; i < ctx->npages; i++) { + if (ctx->should_dirty) + set_page_dirty(ctx->bv[i].bv_page); + put_page(ctx->bv[i].bv_page); + } + + ctx->total_len = ctx->len - iov_iter_count(to); + + cifs_stats_bytes_read(tcon, ctx->total_len); + + /* mask nodata case */ + if (rc == -ENODATA) + rc = 0; + + ctx->rc = (rc == 0) ? (ssize_t)ctx->total_len : rc; + + mutex_unlock(&ctx->aio_mutex); + + if (ctx->iocb && ctx->iocb->ki_complete) + ctx->iocb->ki_complete(ctx->iocb, ctx->rc, 0); + else + complete(&ctx->done); +} + +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 *cfile; + struct cifs_aio_ctx *ctx; + + len = iov_iter_count(to); + if (!len) + return 0; + + cifs_sb = CIFS_FILE_SB(file); + cfile = file->private_data; + tcon = tlink_tcon(cfile->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"); + + ctx = cifs_aio_ctx_alloc(); + if (!ctx) + return -ENOMEM; + + ctx->cfile = cifsFileInfo_get(cfile); + + if (!is_sync_kiocb(iocb)) + ctx->iocb = iocb; + + if (to->type == ITER_IOVEC) + ctx->should_dirty = true; + + rc = setup_aio_ctx_iter(ctx, to, READ); + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } + + len = ctx->len; + + /* grab a lock here due to read response handlers can access ctx */ + mutex_lock(&ctx->aio_mutex); + + rc = cifs_send_async_read(offset, len, cfile, cifs_sb, &ctx->list, ctx); + + /* if at least one read request send succeeded, then reset rc */ + if (!list_empty(&ctx->list)) + rc = 0; + + mutex_unlock(&ctx->aio_mutex); + + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } + + if (!is_sync_kiocb(iocb)) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return -EIOCBQUEUED; + } + + rc = wait_for_completion_killable(&ctx->done); + if (rc) { + mutex_lock(&ctx->aio_mutex); + ctx->rc = rc = -EINTR; + total_read = ctx->total_len; + mutex_unlock(&ctx->aio_mutex); + } else { + rc = ctx->rc; + total_read = ctx->total_len; + } + + kref_put(&ctx->refcount, cifs_aio_ctx_release); + + 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->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 vm_fault_t +cifs_page_mkwrite(struct vm_fault *vmf) +{ + struct page *page = vmf->page; + + lock_page(page); + return VM_FAULT_LOCKED; +} + +static const 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 xid, rc = 0; + struct inode *inode = file_inode(file); + + xid = get_xid(); + + if (!CIFS_CACHE_READ(CIFS_I(inode))) + rc = cifs_zap_mapping(inode); + if (!rc) + rc = generic_file_mmap(file, vma); + if (!rc) + 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); + if (!rc) + rc = generic_file_mmap(file, vma); + if (!rc) + 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_SIZE, got_bytes); + + put_page(page); + rdata->pages[i] = NULL; + } + kref_put(&rdata->refcount, cifs_readdata_release); +} + +static int +readpages_fill_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, struct iov_iter *iter, + unsigned int len) +{ + int result = 0; + unsigned int i; + u64 eof; + pgoff_t eof_index; + unsigned int nr_pages = rdata->nr_pages; + unsigned int page_offset = rdata->page_offset; + + /* determine the eof that the server (probably) has */ + eof = CIFS_I(rdata->mapping->host)->server_eof; + eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0; + cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index); + + rdata->got_bytes = 0; + rdata->tailsz = PAGE_SIZE; + for (i = 0; i < nr_pages; i++) { + struct page *page = rdata->pages[i]; + unsigned int to_read = rdata->pagesz; + size_t n; + + if (i == 0) + to_read -= page_offset; + else + page_offset = 0; + + n = to_read; + + if (len >= to_read) { + len -= to_read; + } else if (len > 0) { + /* enough for partial page, fill and zero the rest */ + zero_user(page, len + page_offset, to_read - len); + n = 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_SIZE); + lru_cache_add_file(page); + flush_dcache_page(page); + SetPageUptodate(page); + unlock_page(page); + put_page(page); + rdata->pages[i] = NULL; + rdata->nr_pages--; + continue; + } else { + /* no need to hold page hostage */ + lru_cache_add_file(page); + unlock_page(page); + put_page(page); + rdata->pages[i] = NULL; + rdata->nr_pages--; + continue; + } + + if (iter) + result = copy_page_from_iter( + page, page_offset, n, iter); +#ifdef CONFIG_CIFS_SMB_DIRECT + else if (rdata->mr) + result = n; +#endif + else + result = cifs_read_page_from_socket( + server, page, page_offset, n); + if (result < 0) + break; + + rdata->got_bytes += result; + } + + return rdata->got_bytes > 0 && result != -ECONNABORTED ? + rdata->got_bytes : result; +} + +static int +cifs_readpages_read_into_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, unsigned int len) +{ + return readpages_fill_pages(server, rdata, NULL, len); +} + +static int +cifs_readpages_copy_into_pages(struct TCP_Server_Info *server, + struct cifs_readdata *rdata, + struct iov_iter *iter) +{ + return readpages_fill_pages(server, rdata, iter, iter->count); +} + +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; + gfp_t gfp = readahead_gfp_mask(mapping); + + 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. + */ + __SetPageLocked(page); + rc = add_to_page_cache_locked(page, mapping, + page->index, gfp); + + /* give up if we can't stick it in the cache */ + if (rc) { + __ClearPageLocked(page); + return rc; + } + + /* move first page to the tmplist */ + *offset = (loff_t)page->index << PAGE_SHIFT; + *bytes = PAGE_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_SIZE > rsize) + break; + + __SetPageLocked(page); + rc = add_to_page_cache_locked(page, mapping, page->index, gfp); + if (rc) { + __ClearPageLocked(page); + break; + } + list_move_tail(&page->lru, tmplist); + (*bytes) += PAGE_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; + int err = 0; + 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) && !err) { + 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_SIZE)) { + add_credits_and_wake_if(server, credits, 0); + return 0; + } + + nr_pages = 0; + err = readpages_get_pages(mapping, page_list, rsize, &tmplist, + &nr_pages, &offset, &bytes); + if (!nr_pages) { + 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); + put_page(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_SIZE; + rdata->tailsz = PAGE_SIZE; + rdata->read_into_pages = cifs_readpages_read_into_pages; + rdata->copy_into_pages = cifs_readpages_copy_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 || + !(rc = 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); + put_page(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_SIZE, poffset); + + if (rc < 0) + goto io_error; + else + cifs_dbg(FYI, "Bytes read %d\n", rc); + + file_inode(file)->i_atime = + current_time(file_inode(file)); + + if (PAGE_SIZE > rc) + memset(read_data + rc, 0, PAGE_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_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_inode->open_file_lock); + list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { + if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) { + spin_unlock(&cifs_inode->open_file_lock); + return 1; + } + } + spin_unlock(&cifs_inode->open_file_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_SHIFT; + loff_t offset = pos & (PAGE_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_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_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); + put_page(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_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_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; + bool purge_cache = false; + + wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS, + TASK_UNINTERRUPTIBLE); + + server->ops->downgrade_oplock(server, cinode, cfile->oplock_level, + cfile->oplock_epoch, &purge_cache); + + 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) || purge_cache) { + 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); + if (CIFS_CACHE_WRITE(cinode)) + goto oplock_break_ack; + } + + rc = cifs_push_locks(cfile); + if (rc) + cifs_dbg(VFS, "Push locks rc = %d\n", rc); + +oplock_break_ack: + /* + * 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); + } + _cifsFileInfo_put(cfile, false /* do not wait for ourself */); + 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) +{ + /* + * 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, +}; |