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file.c
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file.c
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/*
* fs/cifs/file.c
*
* vfs operations that deal with files
*
* Copyright (C) International Business Machines Corp., 2002,2010
* Author(s): Steve French (sfrench@us.ibm.com)
* Jeremy Allison (jra@samba.org)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/backing-dev.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/writeback.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/delay.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "fscache.h"
static inline int cifs_convert_flags(unsigned int flags)
{
if ((flags & O_ACCMODE) == O_RDONLY)
return GENERIC_READ;
else if ((flags & O_ACCMODE) == O_WRONLY)
return GENERIC_WRITE;
else if ((flags & O_ACCMODE) == O_RDWR) {
/* GENERIC_ALL is too much permission to request
can cause unnecessary access denied on create */
/* return GENERIC_ALL; */
return (GENERIC_READ | GENERIC_WRITE);
}
return (READ_CONTROL | FILE_WRITE_ATTRIBUTES | FILE_READ_ATTRIBUTES |
FILE_WRITE_EA | FILE_APPEND_DATA | FILE_WRITE_DATA |
FILE_READ_DATA);
}
static u32 cifs_posix_convert_flags(unsigned int flags)
{
u32 posix_flags = 0;
if ((flags & O_ACCMODE) == O_RDONLY)
posix_flags = SMB_O_RDONLY;
else if ((flags & O_ACCMODE) == O_WRONLY)
posix_flags = SMB_O_WRONLY;
else if ((flags & O_ACCMODE) == O_RDWR)
posix_flags = SMB_O_RDWR;
if (flags & O_CREAT) {
posix_flags |= SMB_O_CREAT;
if (flags & O_EXCL)
posix_flags |= SMB_O_EXCL;
} else if (flags & O_EXCL)
cifs_dbg(FYI, "Application %s pid %d has incorrectly set O_EXCL flag but not O_CREAT on file open. Ignoring O_EXCL\n",
current->comm, current->tgid);
if (flags & O_TRUNC)
posix_flags |= SMB_O_TRUNC;
/* be safe and imply O_SYNC for O_DSYNC */
if (flags & O_DSYNC)
posix_flags |= SMB_O_SYNC;
if (flags & O_DIRECTORY)
posix_flags |= SMB_O_DIRECTORY;
if (flags & O_NOFOLLOW)
posix_flags |= SMB_O_NOFOLLOW;
if (flags & O_DIRECT)
posix_flags |= SMB_O_DIRECT;
return posix_flags;
}
static inline int cifs_get_disposition(unsigned int flags)
{
if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
return FILE_CREATE;
else if ((flags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
return FILE_OVERWRITE_IF;
else if ((flags & O_CREAT) == O_CREAT)
return FILE_OPEN_IF;
else if ((flags & O_TRUNC) == O_TRUNC)
return FILE_OVERWRITE;
else
return FILE_OPEN;
}
int cifs_posix_open(char *full_path, struct inode **pinode,
struct super_block *sb, int mode, unsigned int f_flags,
__u32 *poplock, __u16 *pnetfid, unsigned int xid)
{
int rc;
FILE_UNIX_BASIC_INFO *presp_data;
__u32 posix_flags = 0;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct cifs_fattr fattr;
struct tcon_link *tlink;
struct cifs_tcon *tcon;
cifs_dbg(FYI, "posix open %s\n", full_path);
presp_data = kzalloc(sizeof(FILE_UNIX_BASIC_INFO), GFP_KERNEL);
if (presp_data == NULL)
return -ENOMEM;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
goto posix_open_ret;
}
tcon = tlink_tcon(tlink);
mode &= ~current_umask();
posix_flags = cifs_posix_convert_flags(f_flags);
rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
poplock, full_path, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
cifs_put_tlink(tlink);
if (rc)
goto posix_open_ret;
if (presp_data->Type == cpu_to_le32(-1))
goto posix_open_ret; /* open ok, caller does qpathinfo */
if (!pinode)
goto posix_open_ret; /* caller does not need info */
cifs_unix_basic_to_fattr(&fattr, presp_data, cifs_sb);
/* get new inode and set it up */
if (*pinode == NULL) {
cifs_fill_uniqueid(sb, &fattr);
*pinode = cifs_iget(sb, &fattr);
if (!*pinode) {
rc = -ENOMEM;
goto posix_open_ret;
}
} else {
cifs_fattr_to_inode(*pinode, &fattr);
}
posix_open_ret:
kfree(presp_data);
return rc;
}
static int
cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
struct cifs_tcon *tcon, unsigned int f_flags, __u32 *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;
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;
rc = server->ops->open(xid, tcon, full_path, disposition,
desired_access, create_options, fid, oplock, buf,
cifs_sb);
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->netfid);
out:
kfree(buf);
return rc;
}
static bool
cifs_has_mand_locks(struct cifsInodeInfo *cinode)
{
struct cifs_fid_locks *cur;
bool has_locks = false;
down_read(&cinode->lock_sem);
list_for_each_entry(cur, &cinode->llist, llist) {
if (!list_empty(&cur->locks)) {
has_locks = true;
break;
}
}
up_read(&cinode->lock_sem);
return has_locks;
}
struct cifsFileInfo *
cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
struct tcon_link *tlink, __u32 oplock)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct cifsInodeInfo *cinode = CIFS_I(inode);
struct cifsFileInfo *cfile;
struct cifs_fid_locks *fdlocks;
struct cifs_tcon *tcon = tlink_tcon(tlink);
struct TCP_Server_Info *server = tcon->ses->server;
cfile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
if (cfile == NULL)
return cfile;
fdlocks = kzalloc(sizeof(struct cifs_fid_locks), GFP_KERNEL);
if (!fdlocks) {
kfree(cfile);
return NULL;
}
INIT_LIST_HEAD(&fdlocks->locks);
fdlocks->cfile = cfile;
cfile->llist = fdlocks;
down_write(&cinode->lock_sem);
list_add(&fdlocks->llist, &cinode->llist);
up_write(&cinode->lock_sem);
cfile->count = 1;
cfile->pid = current->tgid;
cfile->uid = current_fsuid();
cfile->dentry = dget(dentry);
cfile->f_flags = file->f_flags;
cfile->invalidHandle = false;
cfile->tlink = cifs_get_tlink(tlink);
INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
mutex_init(&cfile->fh_mutex);
cifs_sb_active(inode->i_sb);
/*
* If the server returned a read oplock and we have mandatory brlocks,
* set oplock level to None.
*/
if (oplock == server->vals->oplock_read &&
cifs_has_mand_locks(cinode)) {
cifs_dbg(FYI, "Reset oplock val from read to None due to mand locks\n");
oplock = 0;
}
spin_lock(&cifs_file_list_lock);
if (fid->pending_open->oplock != CIFS_OPLOCK_NO_CHANGE && oplock)
oplock = fid->pending_open->oplock;
list_del(&fid->pending_open->olist);
server->ops->set_fid(cfile, fid, oplock);
list_add(&cfile->tlist, &tcon->openFileList);
/* if readable file instance put first in list*/
if (file->f_mode & FMODE_READ)
list_add(&cfile->flist, &cinode->openFileList);
else
list_add_tail(&cfile->flist, &cinode->openFileList);
spin_unlock(&cifs_file_list_lock);
file->private_data = cfile;
return cfile;
}
struct cifsFileInfo *
cifsFileInfo_get(struct cifsFileInfo *cifs_file)
{
spin_lock(&cifs_file_list_lock);
cifsFileInfo_get_locked(cifs_file);
spin_unlock(&cifs_file_list_lock);
return cifs_file;
}
/*
* Release a reference on the file private data. This may involve closing
* the filehandle out on the server. Must be called without holding
* cifs_file_list_lock.
*/
void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
{
struct inode *inode = cifs_file->dentry->d_inode;
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;
spin_lock(&cifs_file_list_lock);
if (--cifs_file->count > 0) {
spin_unlock(&cifs_file_list_lock);
return;
}
if (server->ops->get_lease_key)
server->ops->get_lease_key(inode, &fid);
/* store open in pending opens to make sure we don't miss lease break */
cifs_add_pending_open_locked(&fid, cifs_file->tlink, &open);
/* remove it from the lists */
list_del(&cifs_file->flist);
list_del(&cifs_file->tlist);
if (list_empty(&cifsi->openFileList)) {
cifs_dbg(FYI, "closing last open instance for inode %p\n",
cifs_file->dentry->d_inode);
/*
* In strict cache mode we need invalidate mapping on the last
* close because it may cause a error when we open this file
* again and get at least level II oplock.
*/
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
CIFS_I(inode)->invalid_mapping = true;
cifs_set_oplock_level(cifsi, 0);
}
spin_unlock(&cifs_file_list_lock);
cancel_work_sync(&cifs_file->oplock_break);
if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
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);
}
cifs_del_pending_open(&open);
/*
* Delete any outstanding lock records. We'll lose them when the file
* is closed anyway.
*/
down_write(&cifsi->lock_sem);
list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
kfree(li);
}
list_del(&cifs_file->llist->llist);
kfree(cifs_file->llist);
up_write(&cifsi->lock_sem);
cifs_put_tlink(cifs_file->tlink);
dput(cifs_file->dentry);
cifs_sb_deactive(sb);
kfree(cifs_file);
}
int cifs_open(struct inode *inode, struct file *file)
{
int rc = -EACCES;
unsigned int xid;
__u32 oplock;
struct cifs_sb_info *cifs_sb;
struct TCP_Server_Info *server;
struct cifs_tcon *tcon;
struct tcon_link *tlink;
struct cifsFileInfo *cfile = NULL;
char *full_path = NULL;
bool posix_open_ok = false;
struct cifs_fid fid;
struct cifs_pending_open open;
xid = get_xid();
cifs_sb = CIFS_SB(inode->i_sb);
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
free_xid(xid);
return PTR_ERR(tlink);
}
tcon = tlink_tcon(tlink);
server = tcon->ses->server;
full_path = build_path_from_dentry(file->f_path.dentry);
if (full_path == NULL) {
rc = -ENOMEM;
goto out;
}
cifs_dbg(FYI, "inode = 0x%p file flags are 0x%x for %s\n",
inode, file->f_flags, full_path);
if (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(cfile->dentry->d_inode);
struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
int rc = 0;
down_read(&cinode->lock_sem);
if (cinode->can_cache_brlcks) {
/* can cache locks - no need to relock */
up_read(&cinode->lock_sem);
return rc;
}
if (cap_unix(tcon->ses) &&
(CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
rc = cifs_push_posix_locks(cfile);
else
rc = tcon->ses->server->ops->push_mand_locks(cfile);
up_read(&cinode->lock_sem);
return rc;
}
static int
cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
{
int rc = -EACCES;
unsigned int xid;
__u32 oplock;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
struct cifsInodeInfo *cinode;
struct inode *inode;
char *full_path = NULL;
int desired_access;
int disposition = FILE_OPEN;
int create_options = CREATE_NOT_DIR;
struct cifs_fid fid;
xid = get_xid();
mutex_lock(&cfile->fh_mutex);
if (!cfile->invalidHandle) {
mutex_unlock(&cfile->fh_mutex);
rc = 0;
free_xid(xid);
return rc;
}
inode = cfile->dentry->d_inode;
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, &fid.netfid, xid);
if (rc == 0) {
cifs_dbg(FYI, "posix reopen succeeded\n");
goto reopen_success;
}
/*
* fallthrough to retry open the old way on errors, especially
* in the reconnect path it is important to retry hard
*/
}
desired_access = cifs_convert_flags(cfile->f_flags);
if (backup_cred(cifs_sb))
create_options |= CREATE_OPEN_BACKUP_INTENT;
if (server->ops->get_lease_key)
server->ops->get_lease_key(inode, &fid);
/*
* Can not refresh inode by passing in file_info buf to be returned by
* CIFSSMBOpen 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, tcon, full_path, disposition,
desired_access, create_options, &fid, &oplock,
NULL, cifs_sb);
if (rc) {
mutex_unlock(&cfile->fh_mutex);
cifs_dbg(FYI, "cifs_reopen returned 0x%x\n", rc);
cifs_dbg(FYI, "oplock: %d\n", oplock);
goto reopen_error_exit;
}
reopen_success:
cfile->invalidHandle = false;
mutex_unlock(&cfile->fh_mutex);
cinode = CIFS_I(inode);
if (can_flush) {
rc = filemap_write_and_wait(inode->i_mapping);
mapping_set_error(inode->i_mapping, rc);
if (tcon->unix_ext)
rc = cifs_get_inode_info_unix(&inode, full_path,
inode->i_sb, xid);
else
rc = cifs_get_inode_info(&inode, full_path, NULL,
inode->i_sb, xid, NULL);
}
/*
* Else we are writing out data to server already and could deadlock if
* we tried to flush data, and since we do not know if we have data that
* would invalidate the current end of file on the server we can not go
* to the server to get the new inode info.
*/
server->ops->set_fid(cfile, &fid, oplock);
cifs_relock_file(cfile);
reopen_error_exit:
kfree(full_path);
free_xid(xid);
return rc;
}
int cifs_close(struct inode *inode, struct file *file)
{
if (file->private_data != NULL) {
cifsFileInfo_put(file->private_data);
file->private_data = NULL;
}
/* return code from the ->release op is always ignored */
return 0;
}
int cifs_closedir(struct inode *inode, struct file *file)
{
int rc = 0;
unsigned int xid;
struct cifsFileInfo *cfile = file->private_data;
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
char *buf;
cifs_dbg(FYI, "Closedir inode = 0x%p\n", inode);
if (cfile == NULL)
return rc;
xid = get_xid();
tcon = tlink_tcon(cfile->tlink);
server = tcon->ses->server;
cifs_dbg(FYI, "Freeing private data in close dir\n");
spin_lock(&cifs_file_list_lock);
if (!cfile->srch_inf.endOfSearch && !cfile->invalidHandle) {
cfile->invalidHandle = true;
spin_unlock(&cifs_file_list_lock);
if (server->ops->close_dir)
rc = server->ops->close_dir(xid, tcon, &cfile->fid);
else
rc = -ENOSYS;
cifs_dbg(FYI, "Closing uncompleted readdir with rc %d\n", rc);
/* not much we can do if it fails anyway, ignore rc */
rc = 0;
} else
spin_unlock(&cifs_file_list_lock);
buf = cfile->srch_inf.ntwrk_buf_start;
if (buf) {
cifs_dbg(FYI, "closedir free smb buf in srch struct\n");
cfile->srch_inf.ntwrk_buf_start = NULL;
if (cfile->srch_inf.smallBuf)
cifs_small_buf_release(buf);
else
cifs_buf_release(buf);
}
cifs_put_tlink(cfile->tlink);
kfree(file->private_data);
file->private_data = NULL;
/* BB can we lock the filestruct while this is going on? */
free_xid(xid);
return rc;
}
static struct cifsLockInfo *
cifs_lock_init(__u64 offset, __u64 length, __u8 type)
{
struct cifsLockInfo *lock =
kmalloc(sizeof(struct cifsLockInfo), GFP_KERNEL);
if (!lock)
return lock;
lock->offset = offset;
lock->length = length;
lock->type = type;
lock->pid = current->tgid;
INIT_LIST_HEAD(&lock->blist);
init_waitqueue_head(&lock->block_q);
return lock;
}
void
cifs_del_lock_waiters(struct cifsLockInfo *lock)
{
struct cifsLockInfo *li, *tmp;
list_for_each_entry_safe(li, tmp, &lock->blist, blist) {
list_del_init(&li->blist);
wake_up(&li->block_q);
}
}
#define CIFS_LOCK_OP 0
#define CIFS_READ_OP 1
#define CIFS_WRITE_OP 2
/* @rw_check : 0 - no op, 1 - read, 2 - write */
static bool
cifs_find_fid_lock_conflict(struct cifs_fid_locks *fdlocks, __u64 offset,
__u64 length, __u8 type, struct cifsFileInfo *cfile,
struct cifsLockInfo **conf_lock, int rw_check)
{
struct cifsLockInfo *li;
struct cifsFileInfo *cur_cfile = fdlocks->cfile;
struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
list_for_each_entry(li, &fdlocks->locks, llist) {
if (offset + length <= li->offset ||
offset >= li->offset + li->length)
continue;
if (rw_check != CIFS_LOCK_OP && current->tgid == li->pid &&
server->ops->compare_fids(cfile, cur_cfile)) {
/* shared lock prevents write op through the same fid */
if (!(li->type & server->vals->shared_lock_type) ||
rw_check != CIFS_WRITE_OP)
continue;
}
if ((type & server->vals->shared_lock_type) &&
((server->ops->compare_fids(cfile, cur_cfile) &&
current->tgid == li->pid) || type == li->type))
continue;
if (conf_lock)
*conf_lock = li;
return true;
}
return false;
}
bool
cifs_find_lock_conflict(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
__u8 type, struct cifsLockInfo **conf_lock,
int rw_check)
{
bool rc = false;
struct cifs_fid_locks *cur;
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
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(cfile->dentry->d_inode);
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(cfile->dentry->d_inode);
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(cfile->dentry->d_inode);
bool exist;
int rc = 0;
try_again:
exist = false;
down_write(&cinode->lock_sem);
exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
lock->type, &conf_lock, CIFS_LOCK_OP);
if (!exist && cinode->can_cache_brlcks) {
list_add_tail(&lock->llist, &cfile->llist->locks);
up_write(&cinode->lock_sem);
return rc;
}
if (!exist)
rc = 1;
else if (!wait)
rc = -EACCES;
else {
list_add_tail(&lock->blist, &conf_lock->blist);
up_write(&cinode->lock_sem);
rc = wait_event_interruptible(lock->block_q,
(lock->blist.prev == &lock->blist) &&
(lock->blist.next == &lock->blist));
if (!rc)
goto try_again;
down_write(&cinode->lock_sem);
list_del_init(&lock->blist);
}
up_write(&cinode->lock_sem);
return rc;
}
/*
* Check if there is another lock that prevents us to set the lock (posix
* style). If such a lock exists, update the flock structure with its
* properties. Otherwise, set the flock type to F_UNLCK if we can cache brlocks
* or leave it the same if we can't. Returns 0 if we don't need to request to
* the server or 1 otherwise.
*/
static int
cifs_posix_lock_test(struct file *file, struct file_lock *flock)
{
int rc = 0;
struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
unsigned char saved_type = flock->fl_type;
if ((flock->fl_flags & FL_POSIX) == 0)
return 1;
down_read(&cinode->lock_sem);
posix_test_lock(file, flock);
if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
flock->fl_type = saved_type;
rc = 1;
}
up_read(&cinode->lock_sem);
return rc;
}
/*
* Set the byte-range lock (posix style). Returns:
* 1) 0, if we set the lock and don't need to request to the server;
* 2) 1, if we need to request to the server;
* 3) <0, if the error occurs while setting the lock.
*/
static int
cifs_posix_lock_set(struct file *file, struct file_lock *flock)
{
struct cifsInodeInfo *cinode = CIFS_I(file_inode(file));
int rc = 1;
if ((flock->fl_flags & FL_POSIX) == 0)
return rc;
try_again:
down_write(&cinode->lock_sem);
if (!cinode->can_cache_brlcks) {
up_write(&cinode->lock_sem);
return rc;
}
rc = posix_lock_file(file, flock, NULL);
up_write(&cinode->lock_sem);
if (rc == FILE_LOCK_DEFERRED) {
rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
if (!rc)
goto try_again;