linux/fs/cifs/cifsfs.c

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/*
* fs/cifs/cifsfs.c
*
* Copyright (C) International Business Machines Corp., 2002,2008
* Author(s): Steve French (sfrench@us.ibm.com)
*
* Common Internet FileSystem (CIFS) client
*
* 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
*/
/* Note that BB means BUGBUG (ie something to fix eventually) */
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/vfs.h>
#include <linux/mempool.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/freezer.h>
#include <linux/namei.h>
#include <net/ipv6.h>
#include "cifsfs.h"
#include "cifspdu.h"
#define DECLARE_GLOBALS_HERE
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include <linux/mm.h>
#include <linux/key-type.h>
#include "cifs_spnego.h"
#include "fscache.h"
#define CIFS_MAGIC_NUMBER 0xFF534D42 /* the first four bytes of SMB PDUs */
int cifsFYI = 0;
int cifsERROR = 1;
int traceSMB = 0;
bool enable_oplocks = true;
unsigned int linuxExtEnabled = 1;
unsigned int lookupCacheEnabled = 1;
unsigned int global_secflags = CIFSSEC_DEF;
/* unsigned int ntlmv2_support = 0; */
unsigned int sign_CIFS_PDUs = 1;
static const struct super_operations cifs_super_ops;
unsigned int CIFSMaxBufSize = CIFS_MAX_MSGSIZE;
module_param(CIFSMaxBufSize, int, 0);
MODULE_PARM_DESC(CIFSMaxBufSize, "Network buffer size (not including header). "
"Default: 16384 Range: 8192 to 130048");
unsigned int cifs_min_rcv = CIFS_MIN_RCV_POOL;
module_param(cifs_min_rcv, int, 0);
MODULE_PARM_DESC(cifs_min_rcv, "Network buffers in pool. Default: 4 Range: "
"1 to 64");
unsigned int cifs_min_small = 30;
module_param(cifs_min_small, int, 0);
MODULE_PARM_DESC(cifs_min_small, "Small network buffers in pool. Default: 30 "
"Range: 2 to 256");
unsigned int cifs_max_pending = CIFS_MAX_REQ;
module_param(cifs_max_pending, int, 0444);
MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server. "
"Default: 32767 Range: 2 to 32767.");
module_param(enable_oplocks, bool, 0644);
MODULE_PARM_DESC(enable_oplocks, "Enable or disable oplocks (bool). Default:"
"y/Y/1");
extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;
struct workqueue_struct *cifsiod_wq;
static int
cifs_read_super(struct super_block *sb)
{
struct inode *inode;
struct cifs_sb_info *cifs_sb;
int rc = 0;
cifs_sb = CIFS_SB(sb);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIXACL)
sb->s_flags |= MS_POSIXACL;
if (cifs_sb_master_tcon(cifs_sb)->ses->capabilities & CAP_LARGE_FILES)
sb->s_maxbytes = MAX_LFS_FILESIZE;
else
sb->s_maxbytes = MAX_NON_LFS;
/* BB FIXME fix time_gran to be larger for LANMAN sessions */
sb->s_time_gran = 100;
sb->s_magic = CIFS_MAGIC_NUMBER;
sb->s_op = &cifs_super_ops;
sb->s_bdi = &cifs_sb->bdi;
sb->s_blocksize = CIFS_MAX_MSGSIZE;
sb->s_blocksize_bits = 14; /* default 2**14 = CIFS_MAX_MSGSIZE */
inode = cifs_root_iget(sb);
if (IS_ERR(inode)) {
rc = PTR_ERR(inode);
goto out_no_root;
}
sb->s_root = d_make_root(inode);
if (!sb->s_root) {
rc = -ENOMEM;
goto out_no_root;
}
/* do that *after* d_make_root() - we want NULL ->d_op for root here */
if (cifs_sb_master_tcon(cifs_sb)->nocase)
sb->s_d_op = &cifs_ci_dentry_ops;
else
sb->s_d_op = &cifs_dentry_ops;
#ifdef CONFIG_CIFS_NFSD_EXPORT
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
cFYI(1, "export ops supported");
sb->s_export_op = &cifs_export_ops;
}
#endif /* CONFIG_CIFS_NFSD_EXPORT */
return 0;
out_no_root:
cERROR(1, "cifs_read_super: get root inode failed");
return rc;
}
static void cifs_kill_sb(struct super_block *sb)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
kill_anon_super(sb);
cifs_umount(cifs_sb);
}
static int
cifs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
int rc = -EOPNOTSUPP;
int xid;
xid = GetXid();
buf->f_type = CIFS_MAGIC_NUMBER;
/*
* PATH_MAX may be too long - it would presumably be total path,
* but note that some servers (includinng Samba 3) have a shorter
* maximum path.
*
* Instead could get the real value via SMB_QUERY_FS_ATTRIBUTE_INFO.
*/
buf->f_namelen = PATH_MAX;
buf->f_files = 0; /* undefined */
buf->f_ffree = 0; /* unlimited */
/*
* We could add a second check for a QFS Unix capability bit
*/
if ((tcon->ses->capabilities & CAP_UNIX) &&
(CIFS_POSIX_EXTENSIONS & le64_to_cpu(tcon->fsUnixInfo.Capability)))
rc = CIFSSMBQFSPosixInfo(xid, tcon, buf);
/*
* Only need to call the old QFSInfo if failed on newer one,
* e.g. by OS/2.
**/
if (rc && (tcon->ses->capabilities & CAP_NT_SMBS))
rc = CIFSSMBQFSInfo(xid, tcon, buf);
/*
* Some old Windows servers also do not support level 103, retry with
* older level one if old server failed the previous call or we
* bypassed it because we detected that this was an older LANMAN sess
*/
if (rc)
rc = SMBOldQFSInfo(xid, tcon, buf);
FreeXid(xid);
return 0;
}
static int cifs_permission(struct inode *inode, int mask)
{
struct cifs_sb_info *cifs_sb;
cifs_sb = CIFS_SB(inode->i_sb);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) {
if ((mask & MAY_EXEC) && !execute_ok(inode))
return -EACCES;
else
return 0;
} else /* file mode might have been restricted at mount time
on the client (above and beyond ACL on servers) for
servers which do not support setting and viewing mode bits,
so allowing client to check permissions is useful */
return generic_permission(inode, mask);
}
static struct kmem_cache *cifs_inode_cachep;
static struct kmem_cache *cifs_req_cachep;
static struct kmem_cache *cifs_mid_cachep;
static struct kmem_cache *cifs_sm_req_cachep;
mempool_t *cifs_sm_req_poolp;
mempool_t *cifs_req_poolp;
mempool_t *cifs_mid_poolp;
static struct inode *
cifs_alloc_inode(struct super_block *sb)
{
struct cifsInodeInfo *cifs_inode;
cifs_inode = kmem_cache_alloc(cifs_inode_cachep, GFP_KERNEL);
if (!cifs_inode)
return NULL;
cifs_inode->cifsAttrs = 0x20; /* default */
cifs_inode->time = 0;
/* Until the file is open and we have gotten oplock
info back from the server, can not assume caching of
file data or metadata */
cifs_set_oplock_level(cifs_inode, 0);
cifs_inode->delete_pending = false;
cifs_inode->invalid_mapping = false;
cifs_inode->vfs_inode.i_blkbits = 14; /* 2**14 = CIFS_MAX_MSGSIZE */
cifs_inode->server_eof = 0;
cifs_inode->uniqueid = 0;
cifs_inode->createtime = 0;
/* Can not set i_flags here - they get immediately overwritten
to zero by the VFS */
/* cifs_inode->vfs_inode.i_flags = S_NOATIME | S_NOCMTIME;*/
INIT_LIST_HEAD(&cifs_inode->openFileList);
return &cifs_inode->vfs_inode;
}
2011-01-07 07:49:49 +01:00
static void cifs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));
}
static void
cifs_destroy_inode(struct inode *inode)
{
2011-01-07 07:49:49 +01:00
call_rcu(&inode->i_rcu, cifs_i_callback);
}
static void
cifs_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
cifs_fscache_release_inode_cookie(inode);
}
static void
cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
{
struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr;
struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr;
seq_printf(s, ",addr=");
switch (server->dstaddr.ss_family) {
case AF_INET:
seq_printf(s, "%pI4", &sa->sin_addr.s_addr);
break;
case AF_INET6:
seq_printf(s, "%pI6", &sa6->sin6_addr.s6_addr);
if (sa6->sin6_scope_id)
seq_printf(s, "%%%u", sa6->sin6_scope_id);
break;
default:
seq_printf(s, "(unknown)");
}
}
static void
cifs_show_security(struct seq_file *s, struct TCP_Server_Info *server)
{
seq_printf(s, ",sec=");
switch (server->secType) {
case LANMAN:
seq_printf(s, "lanman");
break;
case NTLMv2:
seq_printf(s, "ntlmv2");
break;
case NTLM:
seq_printf(s, "ntlm");
break;
case Kerberos:
seq_printf(s, "krb5");
break;
case RawNTLMSSP:
seq_printf(s, "ntlmssp");
break;
default:
/* shouldn't ever happen */
seq_printf(s, "unknown");
break;
}
if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
seq_printf(s, "i");
}
static void
cifs_show_cache_flavor(struct seq_file *s, struct cifs_sb_info *cifs_sb)
{
seq_printf(s, ",cache=");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
seq_printf(s, "strict");
else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO)
seq_printf(s, "none");
else
seq_printf(s, "loose");
}
/*
* cifs_show_options() is for displaying mount options in /proc/mounts.
* Not all settable options are displayed but most of the important
* ones are.
*/
static int
cifs_show_options(struct seq_file *s, struct dentry *root)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(root->d_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
struct sockaddr *srcaddr;
srcaddr = (struct sockaddr *)&tcon->ses->server->srcaddr;
seq_printf(s, ",vers=%s", tcon->ses->server->vals->version_string);
cifs_show_security(s, tcon->ses->server);
cifs_show_cache_flavor(s, cifs_sb);
seq_printf(s, ",unc=%s", tcon->treeName);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)
seq_printf(s, ",multiuser");
else if (tcon->ses->user_name)
seq_printf(s, ",username=%s", tcon->ses->user_name);
if (tcon->ses->domainName)
seq_printf(s, ",domain=%s", tcon->ses->domainName);
if (srcaddr->sa_family != AF_UNSPEC) {
struct sockaddr_in *saddr4;
struct sockaddr_in6 *saddr6;
saddr4 = (struct sockaddr_in *)srcaddr;
saddr6 = (struct sockaddr_in6 *)srcaddr;
if (srcaddr->sa_family == AF_INET6)
seq_printf(s, ",srcaddr=%pI6c",
&saddr6->sin6_addr);
else if (srcaddr->sa_family == AF_INET)
seq_printf(s, ",srcaddr=%pI4",
&saddr4->sin_addr.s_addr);
else
seq_printf(s, ",srcaddr=BAD-AF:%i",
(int)(srcaddr->sa_family));
}
seq_printf(s, ",uid=%u", cifs_sb->mnt_uid);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
seq_printf(s, ",forceuid");
else
seq_printf(s, ",noforceuid");
seq_printf(s, ",gid=%u", cifs_sb->mnt_gid);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
seq_printf(s, ",forcegid");
else
seq_printf(s, ",noforcegid");
cifs_show_address(s, tcon->ses->server);
if (!tcon->unix_ext)
seq_printf(s, ",file_mode=0%ho,dir_mode=0%ho",
cifs_sb->mnt_file_mode,
cifs_sb->mnt_dir_mode);
if (tcon->seal)
seq_printf(s, ",seal");
if (tcon->nocase)
seq_printf(s, ",nocase");
if (tcon->retry)
seq_printf(s, ",hard");
if (tcon->unix_ext)
seq_printf(s, ",unix");
else
seq_printf(s, ",nounix");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
seq_printf(s, ",posixpaths");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID)
seq_printf(s, ",setuids");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
seq_printf(s, ",serverino");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
seq_printf(s, ",rwpidforward");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL)
seq_printf(s, ",forcemand");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
seq_printf(s, ",nouser_xattr");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
seq_printf(s, ",mapchars");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)
seq_printf(s, ",sfu");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
seq_printf(s, ",nobrl");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL)
seq_printf(s, ",cifsacl");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM)
seq_printf(s, ",dynperm");
if (root->d_sb->s_flags & MS_POSIXACL)
seq_printf(s, ",acl");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
seq_printf(s, ",mfsymlinks");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
seq_printf(s, ",fsc");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)
seq_printf(s, ",nostrictsync");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
seq_printf(s, ",noperm");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID)
seq_printf(s, ",backupuid=%u", cifs_sb->mnt_backupuid);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID)
seq_printf(s, ",backupgid=%u", cifs_sb->mnt_backupgid);
seq_printf(s, ",rsize=%u", cifs_sb->rsize);
seq_printf(s, ",wsize=%u", cifs_sb->wsize);
/* convert actimeo and display it in seconds */
seq_printf(s, ",actimeo=%lu", cifs_sb->actimeo / HZ);
return 0;
}
static void cifs_umount_begin(struct super_block *sb)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct cifs_tcon *tcon;
if (cifs_sb == NULL)
return;
tcon = cifs_sb_master_tcon(cifs_sb);
spin_lock(&cifs_tcp_ses_lock);
if ((tcon->tc_count > 1) || (tcon->tidStatus == CifsExiting)) {
/* we have other mounts to same share or we have
already tried to force umount this and woken up
all waiting network requests, nothing to do */
spin_unlock(&cifs_tcp_ses_lock);
return;
} else if (tcon->tc_count == 1)
tcon->tidStatus = CifsExiting;
spin_unlock(&cifs_tcp_ses_lock);
/* cancel_brl_requests(tcon); */ /* BB mark all brl mids as exiting */
2005-11-10 00:21:09 +01:00
/* cancel_notify_requests(tcon); */
if (tcon->ses && tcon->ses->server) {
cFYI(1, "wake up tasks now - umount begin not complete");
wake_up_all(&tcon->ses->server->request_q);
wake_up_all(&tcon->ses->server->response_q);
msleep(1); /* yield */
/* we have to kick the requests once more */
wake_up_all(&tcon->ses->server->response_q);
msleep(1);
}
return;
}
#ifdef CONFIG_CIFS_STATS2
static int cifs_show_stats(struct seq_file *s, struct dentry *root)
{
/* BB FIXME */
return 0;
}
#endif
static int cifs_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_NODIRATIME;
return 0;
}
static int cifs_drop_inode(struct inode *inode)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
/* no serverino => unconditional eviction */
return !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) ||
generic_drop_inode(inode);
}
static const struct super_operations cifs_super_ops = {
.statfs = cifs_statfs,
.alloc_inode = cifs_alloc_inode,
.destroy_inode = cifs_destroy_inode,
.drop_inode = cifs_drop_inode,
.evict_inode = cifs_evict_inode,
/* .delete_inode = cifs_delete_inode, */ /* Do not need above
function unless later we add lazy close of inodes or unless the
kernel forgets to call us with the same number of releases (closes)
as opens */
.show_options = cifs_show_options,
2005-11-10 00:21:09 +01:00
.umount_begin = cifs_umount_begin,
.remount_fs = cifs_remount,
#ifdef CONFIG_CIFS_STATS2
.show_stats = cifs_show_stats,
#endif
};
/*
* Get root dentry from superblock according to prefix path mount option.
* Return dentry with refcount + 1 on success and NULL otherwise.
*/
static struct dentry *
cifs_get_root(struct smb_vol *vol, struct super_block *sb)
{
struct dentry *dentry;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
char *full_path = NULL;
char *s, *p;
char sep;
full_path = cifs_build_path_to_root(vol, cifs_sb,
cifs_sb_master_tcon(cifs_sb));
if (full_path == NULL)
return ERR_PTR(-ENOMEM);
cFYI(1, "Get root dentry for %s", full_path);
sep = CIFS_DIR_SEP(cifs_sb);
dentry = dget(sb->s_root);
p = s = full_path;
do {
struct inode *dir = dentry->d_inode;
struct dentry *child;
if (!dir) {
dput(dentry);
dentry = ERR_PTR(-ENOENT);
break;
}
/* skip separators */
while (*s == sep)
s++;
if (!*s)
break;
p = s++;
/* next separator */
while (*s && *s != sep)
s++;
mutex_lock(&dir->i_mutex);
child = lookup_one_len(p, dentry, s - p);
mutex_unlock(&dir->i_mutex);
dput(dentry);
dentry = child;
} while (!IS_ERR(dentry));
kfree(full_path);
return dentry;
}
static int cifs_set_super(struct super_block *sb, void *data)
{
struct cifs_mnt_data *mnt_data = data;
sb->s_fs_info = mnt_data->cifs_sb;
return set_anon_super(sb, NULL);
}
static struct dentry *
cifs_do_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
int rc;
struct super_block *sb;
struct cifs_sb_info *cifs_sb;
struct smb_vol *volume_info;
struct cifs_mnt_data mnt_data;
struct dentry *root;
cFYI(1, "Devname: %s flags: %d ", dev_name, flags);
volume_info = cifs_get_volume_info((char *)data, dev_name);
if (IS_ERR(volume_info))
return ERR_CAST(volume_info);
cifs_sb = kzalloc(sizeof(struct cifs_sb_info), GFP_KERNEL);
if (cifs_sb == NULL) {
root = ERR_PTR(-ENOMEM);
goto out_nls;
}
cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
if (cifs_sb->mountdata == NULL) {
root = ERR_PTR(-ENOMEM);
goto out_cifs_sb;
}
cifs_setup_cifs_sb(volume_info, cifs_sb);
rc = cifs_mount(cifs_sb, volume_info);
if (rc) {
if (!(flags & MS_SILENT))
cERROR(1, "cifs_mount failed w/return code = %d", rc);
root = ERR_PTR(rc);
goto out_mountdata;
}
mnt_data.vol = volume_info;
mnt_data.cifs_sb = cifs_sb;
mnt_data.flags = flags;
sb = sget(fs_type, cifs_match_super, cifs_set_super, &mnt_data);
if (IS_ERR(sb)) {
root = ERR_CAST(sb);
cifs_umount(cifs_sb);
goto out;
}
if (sb->s_root) {
cFYI(1, "Use existing superblock");
cifs_umount(cifs_sb);
} else {
sb->s_flags = flags;
/* BB should we make this contingent on mount parm? */
sb->s_flags |= MS_NODIRATIME | MS_NOATIME;
rc = cifs_read_super(sb);
if (rc) {
root = ERR_PTR(rc);
goto out_super;
}
sb->s_flags |= MS_ACTIVE;
}
root = cifs_get_root(volume_info, sb);
if (IS_ERR(root))
goto out_super;
cFYI(1, "dentry root is: %p", root);
goto out;
out_super:
deactivate_locked_super(sb);
out:
cifs_cleanup_volume_info(volume_info);
return root;
out_mountdata:
kfree(cifs_sb->mountdata);
out_cifs_sb:
kfree(cifs_sb);
out_nls:
unload_nls(volume_info->local_nls);
goto out;
}
static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
ssize_t written;
int rc;
written = generic_file_aio_write(iocb, iov, nr_segs, pos);
if (CIFS_I(inode)->clientCanCacheAll)
return written;
rc = filemap_fdatawrite(inode->i_mapping);
if (rc)
cFYI(1, "cifs_file_aio_write: %d rc on %p inode", rc, inode);
return written;
}
static loff_t cifs_llseek(struct file *file, loff_t offset, int origin)
{
/*
* origin == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
* the cached file length
*/
if (origin != SEEK_SET && origin != SEEK_CUR) {
int rc;
struct inode *inode = file->f_path.dentry->d_inode;
/*
* We need to be sure that all dirty pages are written and the
* server has the newest file length.
*/
if (!CIFS_I(inode)->clientCanCacheRead && inode->i_mapping &&
inode->i_mapping->nrpages != 0) {
rc = filemap_fdatawait(inode->i_mapping);
if (rc) {
mapping_set_error(inode->i_mapping, rc);
return rc;
}
}
/*
* Some applications poll for the file length in this strange
* way so we must seek to end on non-oplocked files by
* setting the revalidate time to zero.
*/
CIFS_I(inode)->time = 0;
rc = cifs_revalidate_file_attr(file);
if (rc < 0)
return (loff_t)rc;
}
vfs: do (nearly) lockless generic_file_llseek The i_mutex lock use of generic _file_llseek hurts. Independent processes accessing the same file synchronize over a single lock, even though they have no need for synchronization at all. Under high utilization this can cause llseek to scale very poorly on larger systems. This patch does some rethinking of the llseek locking model: First the 64bit f_pos is not necessarily atomic without locks on 32bit systems. This can already cause races with read() today. This was discussed on linux-kernel in the past and deemed acceptable. The patch does not change that. Let's look at the different seek variants: SEEK_SET: Doesn't really need any locking. If there's a race one writer wins, the other loses. For 32bit the non atomic update races against read() stay the same. Without a lock they can also happen against write() now. The read() race was deemed acceptable in past discussions, and I think if it's ok for read it's ok for write too. => Don't need a lock. SEEK_END: This behaves like SEEK_SET plus it reads the maximum size too. Reading the maximum size would have the 32bit atomic problem. But luckily we already have a way to read the maximum size without locking (i_size_read), so we can just use that instead. Without i_mutex there is no synchronization with write() anymore, however since the write() update is atomic on 64bit it just behaves like another racy SEEK_SET. On non atomic 32bit it's the same as SEEK_SET. => Don't need a lock, but need to use i_size_read() SEEK_CUR: This has a read-modify-write race window on the same file. One could argue that any application doing unsynchronized seeks on the same file is already broken. But for the sake of not adding a regression here I'm using the file->f_lock to synchronize this. Using this lock is much better than the inode mutex because it doesn't synchronize between processes. => So still need a lock, but can use a f_lock. This patch implements this new scheme in generic_file_llseek. I dropped generic_file_llseek_unlocked and changed all callers. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-09-16 01:06:48 +02:00
return generic_file_llseek(file, offset, origin);
}
static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
{
/* note that this is called by vfs setlease with lock_flocks held
to protect *lease from going away */
struct inode *inode = file->f_path.dentry->d_inode;
struct cifsFileInfo *cfile = file->private_data;
if (!(S_ISREG(inode->i_mode)))
return -EINVAL;
/* check if file is oplocked */
if (((arg == F_RDLCK) &&
(CIFS_I(inode)->clientCanCacheRead)) ||
((arg == F_WRLCK) &&
(CIFS_I(inode)->clientCanCacheAll)))
return generic_setlease(file, arg, lease);
else if (tlink_tcon(cfile->tlink)->local_lease &&
!CIFS_I(inode)->clientCanCacheRead)
/* If the server claims to support oplock on this
file, then we still need to check oplock even
if the local_lease mount option is set, but there
are servers which do not support oplock for which
this mount option may be useful if the user
knows that the file won't be changed on the server
by anyone else */
return generic_setlease(file, arg, lease);
else
return -EAGAIN;
}
struct file_system_type cifs_fs_type = {
.owner = THIS_MODULE,
.name = "cifs",
.mount = cifs_do_mount,
.kill_sb = cifs_kill_sb,
/* .fs_flags */
};
const struct inode_operations cifs_dir_inode_ops = {
.create = cifs_create,
.lookup = cifs_lookup,
.getattr = cifs_getattr,
.unlink = cifs_unlink,
.link = cifs_hardlink,
.mkdir = cifs_mkdir,
.rmdir = cifs_rmdir,
.rename = cifs_rename,
.permission = cifs_permission,
/* revalidate:cifs_revalidate, */
.setattr = cifs_setattr,
.symlink = cifs_symlink,
.mknod = cifs_mknod,
#ifdef CONFIG_CIFS_XATTR
.setxattr = cifs_setxattr,
.getxattr = cifs_getxattr,
.listxattr = cifs_listxattr,
.removexattr = cifs_removexattr,
#endif
};
const struct inode_operations cifs_file_inode_ops = {
/* revalidate:cifs_revalidate, */
.setattr = cifs_setattr,
.getattr = cifs_getattr, /* do we need this anymore? */
.rename = cifs_rename,
.permission = cifs_permission,
#ifdef CONFIG_CIFS_XATTR
.setxattr = cifs_setxattr,
.getxattr = cifs_getxattr,
.listxattr = cifs_listxattr,
.removexattr = cifs_removexattr,
#endif
};
const struct inode_operations cifs_symlink_inode_ops = {
.readlink = generic_readlink,
.follow_link = cifs_follow_link,
.put_link = cifs_put_link,
.permission = cifs_permission,
/* BB add the following two eventually */
/* revalidate: cifs_revalidate,
setattr: cifs_notify_change, *//* BB do we need notify change */
#ifdef CONFIG_CIFS_XATTR
.setxattr = cifs_setxattr,
.getxattr = cifs_getxattr,
.listxattr = cifs_listxattr,
.removexattr = cifs_removexattr,
#endif
};
const struct file_operations cifs_file_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
.lock = cifs_lock,
.fsync = cifs_fsync,
.flush = cifs_flush,
.mmap = cifs_file_mmap,
.splice_read = generic_file_splice_read,
.llseek = cifs_llseek,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.setlease = cifs_setlease,
};
const struct file_operations cifs_file_strict_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_strict_readv,
.aio_write = cifs_strict_writev,
.open = cifs_open,
.release = cifs_close,
.lock = cifs_lock,
.fsync = cifs_strict_fsync,
.flush = cifs_flush,
.mmap = cifs_file_strict_mmap,
.splice_read = generic_file_splice_read,
.llseek = cifs_llseek,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.setlease = cifs_setlease,
};
const struct file_operations cifs_file_direct_ops = {
/* BB reevaluate whether they can be done with directio, no cache */
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_user_readv,
.aio_write = cifs_user_writev,
.open = cifs_open,
.release = cifs_close,
.lock = cifs_lock,
.fsync = cifs_fsync,
.flush = cifs_flush,
.mmap = cifs_file_mmap,
.splice_read = generic_file_splice_read,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.llseek = cifs_llseek,
.setlease = cifs_setlease,
};
const struct file_operations cifs_file_nobrl_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
.fsync = cifs_fsync,
.flush = cifs_flush,
.mmap = cifs_file_mmap,
.splice_read = generic_file_splice_read,
.llseek = cifs_llseek,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.setlease = cifs_setlease,
};
const struct file_operations cifs_file_strict_nobrl_ops = {
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_strict_readv,
.aio_write = cifs_strict_writev,
.open = cifs_open,
.release = cifs_close,
.fsync = cifs_strict_fsync,
.flush = cifs_flush,
.mmap = cifs_file_strict_mmap,
.splice_read = generic_file_splice_read,
.llseek = cifs_llseek,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.setlease = cifs_setlease,
};
const struct file_operations cifs_file_direct_nobrl_ops = {
/* BB reevaluate whether they can be done with directio, no cache */
.read = do_sync_read,
.write = do_sync_write,
.aio_read = cifs_user_readv,
.aio_write = cifs_user_writev,
.open = cifs_open,
.release = cifs_close,
.fsync = cifs_fsync,
.flush = cifs_flush,
.mmap = cifs_file_mmap,
.splice_read = generic_file_splice_read,
#ifdef CONFIG_CIFS_POSIX
.unlocked_ioctl = cifs_ioctl,
#endif /* CONFIG_CIFS_POSIX */
.llseek = cifs_llseek,
.setlease = cifs_setlease,
};
const struct file_operations cifs_dir_ops = {
.readdir = cifs_readdir,
.release = cifs_closedir,
.read = generic_read_dir,
.unlocked_ioctl = cifs_ioctl,
.llseek = generic_file_llseek,
};
static void
cifs_init_once(void *inode)
{
struct cifsInodeInfo *cifsi = inode;
inode_init_once(&cifsi->vfs_inode);
mutex_init(&cifsi->lock_mutex);
}
static int
cifs_init_inodecache(void)
{
cifs_inode_cachep = kmem_cache_create("cifs_inode_cache",
sizeof(struct cifsInodeInfo),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
cifs_init_once);
if (cifs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void
cifs_destroy_inodecache(void)
{
kmem_cache_destroy(cifs_inode_cachep);
}
static int
cifs_init_request_bufs(void)
{
if (CIFSMaxBufSize < 8192) {
/* Buffer size can not be smaller than 2 * PATH_MAX since maximum
Unicode path name has to fit in any SMB/CIFS path based frames */
CIFSMaxBufSize = 8192;
} else if (CIFSMaxBufSize > 1024*127) {
CIFSMaxBufSize = 1024 * 127;
} else {
CIFSMaxBufSize &= 0x1FE00; /* Round size to even 512 byte mult*/
}
/* cERROR(1, "CIFSMaxBufSize %d 0x%x",CIFSMaxBufSize,CIFSMaxBufSize); */
cifs_req_cachep = kmem_cache_create("cifs_request",
CIFSMaxBufSize +
MAX_CIFS_HDR_SIZE, 0,
SLAB_HWCACHE_ALIGN, NULL);
if (cifs_req_cachep == NULL)
return -ENOMEM;
if (cifs_min_rcv < 1)
cifs_min_rcv = 1;
else if (cifs_min_rcv > 64) {
cifs_min_rcv = 64;
cERROR(1, "cifs_min_rcv set to maximum (64)");
}
cifs_req_poolp = mempool_create_slab_pool(cifs_min_rcv,
cifs_req_cachep);
if (cifs_req_poolp == NULL) {
kmem_cache_destroy(cifs_req_cachep);
return -ENOMEM;
}
/* MAX_CIFS_SMALL_BUFFER_SIZE bytes is enough for most SMB responses and
almost all handle based requests (but not write response, nor is it
sufficient for path based requests). A smaller size would have
been more efficient (compacting multiple slab items on one 4k page)
for the case in which debug was on, but this larger size allows
more SMBs to use small buffer alloc and is still much more
efficient to alloc 1 per page off the slab compared to 17K (5page)
alloc of large cifs buffers even when page debugging is on */
cifs_sm_req_cachep = kmem_cache_create("cifs_small_rq",
MAX_CIFS_SMALL_BUFFER_SIZE, 0, SLAB_HWCACHE_ALIGN,
NULL);
if (cifs_sm_req_cachep == NULL) {
mempool_destroy(cifs_req_poolp);
kmem_cache_destroy(cifs_req_cachep);
return -ENOMEM;
}
if (cifs_min_small < 2)
cifs_min_small = 2;
else if (cifs_min_small > 256) {
cifs_min_small = 256;
cFYI(1, "cifs_min_small set to maximum (256)");
}
cifs_sm_req_poolp = mempool_create_slab_pool(cifs_min_small,
cifs_sm_req_cachep);
if (cifs_sm_req_poolp == NULL) {
mempool_destroy(cifs_req_poolp);
kmem_cache_destroy(cifs_req_cachep);
kmem_cache_destroy(cifs_sm_req_cachep);
return -ENOMEM;
}
return 0;
}
static void
cifs_destroy_request_bufs(void)
{
mempool_destroy(cifs_req_poolp);
kmem_cache_destroy(cifs_req_cachep);
mempool_destroy(cifs_sm_req_poolp);
kmem_cache_destroy(cifs_sm_req_cachep);
}
static int
cifs_init_mids(void)
{
cifs_mid_cachep = kmem_cache_create("cifs_mpx_ids",
sizeof(struct mid_q_entry), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (cifs_mid_cachep == NULL)
return -ENOMEM;
/* 3 is a reasonable minimum number of simultaneous operations */
cifs_mid_poolp = mempool_create_slab_pool(3, cifs_mid_cachep);
if (cifs_mid_poolp == NULL) {
kmem_cache_destroy(cifs_mid_cachep);
return -ENOMEM;
}
return 0;
}
static void
cifs_destroy_mids(void)
{
mempool_destroy(cifs_mid_poolp);
kmem_cache_destroy(cifs_mid_cachep);
}
static int __init
init_cifs(void)
{
int rc = 0;
cifs_proc_init();
INIT_LIST_HEAD(&cifs_tcp_ses_list);
#ifdef CONFIG_CIFS_DNOTIFY_EXPERIMENTAL /* unused temporarily */
INIT_LIST_HEAD(&GlobalDnotifyReqList);
INIT_LIST_HEAD(&GlobalDnotifyRsp_Q);
#endif /* was needed for dnotify, and will be needed for inotify when VFS fix */
/*
* Initialize Global counters
*/
atomic_set(&sesInfoAllocCount, 0);
atomic_set(&tconInfoAllocCount, 0);
atomic_set(&tcpSesAllocCount, 0);
atomic_set(&tcpSesReconnectCount, 0);
atomic_set(&tconInfoReconnectCount, 0);
atomic_set(&bufAllocCount, 0);
atomic_set(&smBufAllocCount, 0);
#ifdef CONFIG_CIFS_STATS2
atomic_set(&totBufAllocCount, 0);
atomic_set(&totSmBufAllocCount, 0);
#endif /* CONFIG_CIFS_STATS2 */
atomic_set(&midCount, 0);
GlobalCurrentXid = 0;
GlobalTotalActiveXid = 0;
GlobalMaxActiveXid = 0;
spin_lock_init(&cifs_tcp_ses_lock);
spin_lock_init(&cifs_file_list_lock);
spin_lock_init(&GlobalMid_Lock);
if (cifs_max_pending < 2) {
cifs_max_pending = 2;
cFYI(1, "cifs_max_pending set to min of 2");
} else if (cifs_max_pending > CIFS_MAX_REQ) {
cifs_max_pending = CIFS_MAX_REQ;
cFYI(1, "cifs_max_pending set to max of %u", CIFS_MAX_REQ);
}
cifsiod_wq = alloc_workqueue("cifsiod", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
if (!cifsiod_wq) {
rc = -ENOMEM;
goto out_clean_proc;
}
rc = cifs_fscache_register();
if (rc)
goto out_destroy_wq;
rc = cifs_init_inodecache();
if (rc)
goto out_unreg_fscache;
rc = cifs_init_mids();
if (rc)
goto out_destroy_inodecache;
rc = cifs_init_request_bufs();
if (rc)
goto out_destroy_mids;
#ifdef CONFIG_CIFS_UPCALL
rc = register_key_type(&cifs_spnego_key_type);
if (rc)
goto out_destroy_request_bufs;
#endif /* CONFIG_CIFS_UPCALL */
#ifdef CONFIG_CIFS_ACL
rc = init_cifs_idmap();
if (rc)
goto out_register_key_type;
#endif /* CONFIG_CIFS_ACL */
rc = register_filesystem(&cifs_fs_type);
if (rc)
goto out_init_cifs_idmap;
return 0;
out_init_cifs_idmap:
#ifdef CONFIG_CIFS_ACL
exit_cifs_idmap();
out_register_key_type:
#endif
#ifdef CONFIG_CIFS_UPCALL
unregister_key_type(&cifs_spnego_key_type);
out_destroy_request_bufs:
#endif
cifs_destroy_request_bufs();
out_destroy_mids:
cifs_destroy_mids();
out_destroy_inodecache:
cifs_destroy_inodecache();
out_unreg_fscache:
cifs_fscache_unregister();
out_destroy_wq:
destroy_workqueue(cifsiod_wq);
out_clean_proc:
cifs_proc_clean();
return rc;
}
static void __exit
exit_cifs(void)
{
cFYI(DBG2, "exit_cifs");
unregister_filesystem(&cifs_fs_type);
cifs_dfs_release_automount_timer();
#ifdef CONFIG_CIFS_ACL
cifs_destroy_idmaptrees();
exit_cifs_idmap();
#endif
#ifdef CONFIG_CIFS_UPCALL
unregister_key_type(&cifs_spnego_key_type);
#endif
cifs_destroy_request_bufs();
cifs_destroy_mids();
cifs_destroy_inodecache();
cifs_fscache_unregister();
destroy_workqueue(cifsiod_wq);
cifs_proc_clean();
}
MODULE_AUTHOR("Steve French <sfrench@us.ibm.com>");
MODULE_LICENSE("GPL"); /* combination of LGPL + GPL source behaves as GPL */
MODULE_DESCRIPTION
("VFS to access servers complying with the SNIA CIFS Specification "
"e.g. Samba and Windows");
MODULE_VERSION(CIFS_VERSION);
module_init(init_cifs)
module_exit(exit_cifs)