linux/fs/cifs/smb1ops.c

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/*
* SMB1 (CIFS) version specific operations
*
* Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2 as published
* by the Free Software Foundation.
*
* 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/pagemap.h>
#include <linux/vfs.h>
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifspdu.h"
/*
* An NT cancel request header looks just like the original request except:
*
* The Command is SMB_COM_NT_CANCEL
* The WordCount is zeroed out
* The ByteCount is zeroed out
*
* This function mangles an existing request buffer into a
* SMB_COM_NT_CANCEL request and then sends it.
*/
static int
send_nt_cancel(struct TCP_Server_Info *server, void *buf,
struct mid_q_entry *mid)
{
int rc = 0;
struct smb_hdr *in_buf = (struct smb_hdr *)buf;
/* -4 for RFC1001 length and +2 for BCC field */
in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4 + 2);
in_buf->Command = SMB_COM_NT_CANCEL;
in_buf->WordCount = 0;
put_bcc(0, in_buf);
mutex_lock(&server->srv_mutex);
rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
if (rc) {
mutex_unlock(&server->srv_mutex);
return rc;
}
/*
* The response to this call was already factored into the sequence
* number when the call went out, so we must adjust it back downward
* after signing here.
*/
--server->sequence_number;
rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
if (rc < 0)
server->sequence_number--;
mutex_unlock(&server->srv_mutex);
cifs_dbg(FYI, "issued NT_CANCEL for mid %u, rc = %d\n",
get_mid(in_buf), rc);
return rc;
}
static bool
cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
{
return ob1->fid.netfid == ob2->fid.netfid;
}
static unsigned int
cifs_read_data_offset(char *buf)
{
READ_RSP *rsp = (READ_RSP *)buf;
return le16_to_cpu(rsp->DataOffset);
}
static unsigned int
cifs_read_data_length(char *buf)
{
READ_RSP *rsp = (READ_RSP *)buf;
return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
le16_to_cpu(rsp->DataLength);
}
static struct mid_q_entry *
cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
{
struct smb_hdr *buf = (struct smb_hdr *)buffer;
struct mid_q_entry *mid;
spin_lock(&GlobalMid_Lock);
list_for_each_entry(mid, &server->pending_mid_q, qhead) {
if (compare_mid(mid->mid, buf) &&
mid->mid_state == MID_REQUEST_SUBMITTED &&
le16_to_cpu(mid->command) == buf->Command) {
spin_unlock(&GlobalMid_Lock);
return mid;
}
}
spin_unlock(&GlobalMid_Lock);
return NULL;
}
static void
cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add,
const int optype)
{
spin_lock(&server->req_lock);
server->credits += add;
server->in_flight--;
spin_unlock(&server->req_lock);
wake_up(&server->request_q);
}
static void
cifs_set_credits(struct TCP_Server_Info *server, const int val)
{
spin_lock(&server->req_lock);
server->credits = val;
server->oplocks = val > 1 ? enable_oplocks : false;
spin_unlock(&server->req_lock);
}
static int *
cifs_get_credits_field(struct TCP_Server_Info *server, const int optype)
{
return &server->credits;
}
static unsigned int
cifs_get_credits(struct mid_q_entry *mid)
{
return 1;
}
/*
* Find a free multiplex id (SMB mid). Otherwise there could be
* mid collisions which might cause problems, demultiplexing the
* wrong response to this request. Multiplex ids could collide if
* one of a series requests takes much longer than the others, or
* if a very large number of long lived requests (byte range
* locks or FindNotify requests) are pending. No more than
* 64K-1 requests can be outstanding at one time. If no
* mids are available, return zero. A future optimization
* could make the combination of mids and uid the key we use
* to demultiplex on (rather than mid alone).
* In addition to the above check, the cifs demultiplex
* code already used the command code as a secondary
* check of the frame and if signing is negotiated the
* response would be discarded if the mid were the same
* but the signature was wrong. Since the mid is not put in the
* pending queue until later (when it is about to be dispatched)
* we do have to limit the number of outstanding requests
* to somewhat less than 64K-1 although it is hard to imagine
* so many threads being in the vfs at one time.
*/
static __u64
cifs_get_next_mid(struct TCP_Server_Info *server)
{
__u64 mid = 0;
__u16 last_mid, cur_mid;
bool collision;
spin_lock(&GlobalMid_Lock);
/* mid is 16 bit only for CIFS/SMB */
cur_mid = (__u16)((server->CurrentMid) & 0xffff);
/* we do not want to loop forever */
last_mid = cur_mid;
cur_mid++;
/*
* This nested loop looks more expensive than it is.
* In practice the list of pending requests is short,
* fewer than 50, and the mids are likely to be unique
* on the first pass through the loop unless some request
* takes longer than the 64 thousand requests before it
* (and it would also have to have been a request that
* did not time out).
*/
while (cur_mid != last_mid) {
struct mid_q_entry *mid_entry;
unsigned int num_mids;
collision = false;
if (cur_mid == 0)
cur_mid++;
num_mids = 0;
list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
++num_mids;
if (mid_entry->mid == cur_mid &&
mid_entry->mid_state == MID_REQUEST_SUBMITTED) {
/* This mid is in use, try a different one */
collision = true;
break;
}
}
/*
* if we have more than 32k mids in the list, then something
* is very wrong. Possibly a local user is trying to DoS the
* box by issuing long-running calls and SIGKILL'ing them. If
* we get to 2^16 mids then we're in big trouble as this
* function could loop forever.
*
* Go ahead and assign out the mid in this situation, but force
* an eventual reconnect to clean out the pending_mid_q.
*/
if (num_mids > 32768)
server->tcpStatus = CifsNeedReconnect;
if (!collision) {
mid = (__u64)cur_mid;
server->CurrentMid = mid;
break;
}
cur_mid++;
}
spin_unlock(&GlobalMid_Lock);
return mid;
}
/*
return codes:
0 not a transact2, or all data present
>0 transact2 with that much data missing
-EINVAL invalid transact2
*/
static int
check2ndT2(char *buf)
{
struct smb_hdr *pSMB = (struct smb_hdr *)buf;
struct smb_t2_rsp *pSMBt;
int remaining;
__u16 total_data_size, data_in_this_rsp;
if (pSMB->Command != SMB_COM_TRANSACTION2)
return 0;
/* check for plausible wct, bcc and t2 data and parm sizes */
/* check for parm and data offset going beyond end of smb */
if (pSMB->WordCount != 10) { /* coalesce_t2 depends on this */
cifs_dbg(FYI, "invalid transact2 word count\n");
return -EINVAL;
}
pSMBt = (struct smb_t2_rsp *)pSMB;
total_data_size = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
data_in_this_rsp = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
if (total_data_size == data_in_this_rsp)
return 0;
else if (total_data_size < data_in_this_rsp) {
cifs_dbg(FYI, "total data %d smaller than data in frame %d\n",
total_data_size, data_in_this_rsp);
return -EINVAL;
}
remaining = total_data_size - data_in_this_rsp;
cifs_dbg(FYI, "missing %d bytes from transact2, check next response\n",
remaining);
if (total_data_size > CIFSMaxBufSize) {
cifs_dbg(VFS, "TotalDataSize %d is over maximum buffer %d\n",
total_data_size, CIFSMaxBufSize);
return -EINVAL;
}
return remaining;
}
static int
coalesce_t2(char *second_buf, struct smb_hdr *target_hdr)
{
struct smb_t2_rsp *pSMBs = (struct smb_t2_rsp *)second_buf;
struct smb_t2_rsp *pSMBt = (struct smb_t2_rsp *)target_hdr;
char *data_area_of_tgt;
char *data_area_of_src;
int remaining;
unsigned int byte_count, total_in_tgt;
__u16 tgt_total_cnt, src_total_cnt, total_in_src;
src_total_cnt = get_unaligned_le16(&pSMBs->t2_rsp.TotalDataCount);
tgt_total_cnt = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
if (tgt_total_cnt != src_total_cnt)
cifs_dbg(FYI, "total data count of primary and secondary t2 differ source=%hu target=%hu\n",
src_total_cnt, tgt_total_cnt);
total_in_tgt = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
remaining = tgt_total_cnt - total_in_tgt;
if (remaining < 0) {
cifs_dbg(FYI, "Server sent too much data. tgt_total_cnt=%hu total_in_tgt=%hu\n",
tgt_total_cnt, total_in_tgt);
return -EPROTO;
}
if (remaining == 0) {
/* nothing to do, ignore */
cifs_dbg(FYI, "no more data remains\n");
return 0;
}
total_in_src = get_unaligned_le16(&pSMBs->t2_rsp.DataCount);
if (remaining < total_in_src)
cifs_dbg(FYI, "transact2 2nd response contains too much data\n");
/* find end of first SMB data area */
data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +
get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);
/* validate target area */
data_area_of_src = (char *)&pSMBs->hdr.Protocol +
get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);
data_area_of_tgt += total_in_tgt;
total_in_tgt += total_in_src;
/* is the result too big for the field? */
if (total_in_tgt > USHRT_MAX) {
cifs_dbg(FYI, "coalesced DataCount too large (%u)\n",
total_in_tgt);
return -EPROTO;
}
put_unaligned_le16(total_in_tgt, &pSMBt->t2_rsp.DataCount);
/* fix up the BCC */
byte_count = get_bcc(target_hdr);
byte_count += total_in_src;
/* is the result too big for the field? */
if (byte_count > USHRT_MAX) {
cifs_dbg(FYI, "coalesced BCC too large (%u)\n", byte_count);
return -EPROTO;
}
put_bcc(byte_count, target_hdr);
byte_count = be32_to_cpu(target_hdr->smb_buf_length);
byte_count += total_in_src;
/* don't allow buffer to overflow */
if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
cifs_dbg(FYI, "coalesced BCC exceeds buffer size (%u)\n",
byte_count);
return -ENOBUFS;
}
target_hdr->smb_buf_length = cpu_to_be32(byte_count);
/* copy second buffer into end of first buffer */
memcpy(data_area_of_tgt, data_area_of_src, total_in_src);
if (remaining != total_in_src) {
/* more responses to go */
cifs_dbg(FYI, "waiting for more secondary responses\n");
return 1;
}
/* we are done */
cifs_dbg(FYI, "found the last secondary response\n");
return 0;
}
cifs: Wait for writebacks to complete before attempting write. Problem reported in Red Hat bz 1040329 for strict writes where we cache only when we hold oplock and write direct to the server when we don't. When we receive an oplock break, we first change the oplock value for the inode in cifsInodeInfo->oplock to indicate that we no longer hold the oplock before we enqueue a task to flush changes to the backing device. Once we have completed flushing the changes, we return the oplock to the server. There are 2 ways here where we can have data corruption 1) While we flush changes to the backing device as part of the oplock break, we can have processes write to the file. These writes check for the oplock, find none and attempt to write directly to the server. These direct writes made while we are flushing from cache could be overwritten by data being flushed from the cache causing data corruption. 2) While a thread runs in cifs_strict_writev, the machine could receive and process an oplock break after the thread has checked the oplock and found that it allows us to cache and before we have made changes to the cache. In that case, we end up with a dirty page in cache when we shouldn't have any. This will be flushed later and will overwrite all subsequent writes to the part of the file represented by this page. Before making any writes to the server, we need to confirm that we are not in the process of flushing data to the server and if we are, we should wait until the process is complete before we attempt the write. We should also wait for existing writes to complete before we process an oplock break request which changes oplock values. We add a version specific downgrade_oplock() operation to allow for differences in the oplock values set for the different smb versions. Cc: stable@vger.kernel.org Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2014-03-11 16:11:47 +00:00
static void
cifs_downgrade_oplock(struct TCP_Server_Info *server,
struct cifsInodeInfo *cinode, bool set_level2)
{
if (set_level2)
cifs_set_oplock_level(cinode, OPLOCK_READ);
else
cifs_set_oplock_level(cinode, 0);
}
static bool
cifs_check_trans2(struct mid_q_entry *mid, struct TCP_Server_Info *server,
char *buf, int malformed)
{
if (malformed)
return false;
if (check2ndT2(buf) <= 0)
return false;
mid->multiRsp = true;
if (mid->resp_buf) {
/* merge response - fix up 1st*/
malformed = coalesce_t2(buf, mid->resp_buf);
if (malformed > 0)
return true;
/* All parts received or packet is malformed. */
mid->multiEnd = true;
dequeue_mid(mid, malformed);
return true;
}
if (!server->large_buf) {
/*FIXME: switch to already allocated largebuf?*/
cifs_dbg(VFS, "1st trans2 resp needs bigbuf\n");
} else {
/* Have first buffer */
mid->resp_buf = buf;
mid->large_buf = true;
server->bigbuf = NULL;
}
return true;
}
static bool
cifs_need_neg(struct TCP_Server_Info *server)
{
return server->maxBuf == 0;
}
static int
cifs_negotiate(const unsigned int xid, struct cifs_ses *ses)
{
int rc;
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN) {
/* retry only once on 1st time connection */
set_credits(ses->server, 1);
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN)
rc = -EHOSTDOWN;
}
return rc;
}
static unsigned int
cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
struct TCP_Server_Info *server = tcon->ses->server;
unsigned int wsize;
/* start with specified wsize, or default */
if (volume_info->wsize)
wsize = volume_info->wsize;
else if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
wsize = CIFS_DEFAULT_IOSIZE;
else
wsize = CIFS_DEFAULT_NON_POSIX_WSIZE;
/* can server support 24-bit write sizes? (via UNIX extensions) */
if (!tcon->unix_ext || !(unix_cap & CIFS_UNIX_LARGE_WRITE_CAP))
wsize = min_t(unsigned int, wsize, CIFS_MAX_RFC1002_WSIZE);
/*
* no CAP_LARGE_WRITE_X or is signing enabled without CAP_UNIX set?
* Limit it to max buffer offered by the server, minus the size of the
* WRITEX header, not including the 4 byte RFC1001 length.
*/
if (!(server->capabilities & CAP_LARGE_WRITE_X) ||
(!(server->capabilities & CAP_UNIX) && server->sign))
wsize = min_t(unsigned int, wsize,
server->maxBuf - sizeof(WRITE_REQ) + 4);
/* hard limit of CIFS_MAX_WSIZE */
wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE);
return wsize;
}
static unsigned int
cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
{
__u64 unix_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
struct TCP_Server_Info *server = tcon->ses->server;
unsigned int rsize, defsize;
/*
* Set default value...
*
* HACK alert! Ancient servers have very small buffers. Even though
* MS-CIFS indicates that servers are only limited by the client's
* bufsize for reads, testing against win98se shows that it throws
* INVALID_PARAMETER errors if you try to request too large a read.
* OS/2 just sends back short reads.
*
* If the server doesn't advertise CAP_LARGE_READ_X, then assume that
* it can't handle a read request larger than its MaxBufferSize either.
*/
if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_READ_CAP))
defsize = CIFS_DEFAULT_IOSIZE;
else if (server->capabilities & CAP_LARGE_READ_X)
defsize = CIFS_DEFAULT_NON_POSIX_RSIZE;
else
defsize = server->maxBuf - sizeof(READ_RSP);
rsize = volume_info->rsize ? volume_info->rsize : defsize;
/*
* no CAP_LARGE_READ_X? Then MS-CIFS states that we must limit this to
* the client's MaxBufferSize.
*/
if (!(server->capabilities & CAP_LARGE_READ_X))
rsize = min_t(unsigned int, CIFSMaxBufSize, rsize);
/* hard limit of CIFS_MAX_RSIZE */
rsize = min_t(unsigned int, rsize, CIFS_MAX_RSIZE);
return rsize;
}
static void
cifs_qfs_tcon(const unsigned int xid, struct cifs_tcon *tcon)
{
CIFSSMBQFSDeviceInfo(xid, tcon);
CIFSSMBQFSAttributeInfo(xid, tcon);
}
static int
cifs_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path)
{
int rc;
FILE_ALL_INFO *file_info;
file_info = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
if (file_info == NULL)
return -ENOMEM;
rc = CIFSSMBQPathInfo(xid, tcon, full_path, file_info,
0 /* not legacy */, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc == -EOPNOTSUPP || rc == -EINVAL)
rc = SMBQueryInformation(xid, tcon, full_path, file_info,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
kfree(file_info);
return rc;
}
static int
cifs_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
FILE_ALL_INFO *data, bool *adjustTZ, bool *symlink)
{
int rc;
*symlink = false;
/* could do find first instead but this returns more info */
rc = CIFSSMBQPathInfo(xid, tcon, full_path, data, 0 /* not legacy */,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
/*
* BB optimize code so we do not make the above call when server claims
* no NT SMB support and the above call failed at least once - set flag
* in tcon or mount.
*/
if ((rc == -EOPNOTSUPP) || (rc == -EINVAL)) {
rc = SMBQueryInformation(xid, tcon, full_path, data,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
*adjustTZ = true;
}
if (!rc && (le32_to_cpu(data->Attributes) & ATTR_REPARSE)) {
int tmprc;
int oplock = 0;
struct cifs_fid fid;
struct cifs_open_parms oparms;
oparms.tcon = tcon;
oparms.cifs_sb = cifs_sb;
oparms.desired_access = FILE_READ_ATTRIBUTES;
oparms.create_options = 0;
oparms.disposition = FILE_OPEN;
oparms.path = full_path;
oparms.fid = &fid;
oparms.reconnect = false;
/* Need to check if this is a symbolic link or not */
tmprc = CIFS_open(xid, &oparms, &oplock, NULL);
if (tmprc == -EOPNOTSUPP)
*symlink = true;
else
CIFSSMBClose(xid, tcon, fid.netfid);
}
return rc;
}
static int
cifs_get_srv_inum(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
u64 *uniqueid, FILE_ALL_INFO *data)
{
/*
* We can not use the IndexNumber field by default from Windows or
* Samba (in ALL_INFO buf) but we can request it explicitly. The SNIA
* CIFS spec claims that this value is unique within the scope of a
* share, and the windows docs hint that it's actually unique
* per-machine.
*
* There may be higher info levels that work but are there Windows
* server or network appliances for which IndexNumber field is not
* guaranteed unique?
*/
return CIFSGetSrvInodeNumber(xid, tcon, full_path, uniqueid,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
}
static int
cifs_query_file_info(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_fid *fid, FILE_ALL_INFO *data)
{
return CIFSSMBQFileInfo(xid, tcon, fid->netfid, data);
}
static void
cifs_clear_stats(struct cifs_tcon *tcon)
{
#ifdef CONFIG_CIFS_STATS
atomic_set(&tcon->stats.cifs_stats.num_writes, 0);
atomic_set(&tcon->stats.cifs_stats.num_reads, 0);
atomic_set(&tcon->stats.cifs_stats.num_flushes, 0);
atomic_set(&tcon->stats.cifs_stats.num_oplock_brks, 0);
atomic_set(&tcon->stats.cifs_stats.num_opens, 0);
atomic_set(&tcon->stats.cifs_stats.num_posixopens, 0);
atomic_set(&tcon->stats.cifs_stats.num_posixmkdirs, 0);
atomic_set(&tcon->stats.cifs_stats.num_closes, 0);
atomic_set(&tcon->stats.cifs_stats.num_deletes, 0);
atomic_set(&tcon->stats.cifs_stats.num_mkdirs, 0);
atomic_set(&tcon->stats.cifs_stats.num_rmdirs, 0);
atomic_set(&tcon->stats.cifs_stats.num_renames, 0);
atomic_set(&tcon->stats.cifs_stats.num_t2renames, 0);
atomic_set(&tcon->stats.cifs_stats.num_ffirst, 0);
atomic_set(&tcon->stats.cifs_stats.num_fnext, 0);
atomic_set(&tcon->stats.cifs_stats.num_fclose, 0);
atomic_set(&tcon->stats.cifs_stats.num_hardlinks, 0);
atomic_set(&tcon->stats.cifs_stats.num_symlinks, 0);
atomic_set(&tcon->stats.cifs_stats.num_locks, 0);
atomic_set(&tcon->stats.cifs_stats.num_acl_get, 0);
atomic_set(&tcon->stats.cifs_stats.num_acl_set, 0);
#endif
}
static void
cifs_print_stats(struct seq_file *m, struct cifs_tcon *tcon)
{
#ifdef CONFIG_CIFS_STATS
seq_printf(m, " Oplocks breaks: %d",
atomic_read(&tcon->stats.cifs_stats.num_oplock_brks));
seq_printf(m, "\nReads: %d Bytes: %llu",
atomic_read(&tcon->stats.cifs_stats.num_reads),
(long long)(tcon->bytes_read));
seq_printf(m, "\nWrites: %d Bytes: %llu",
atomic_read(&tcon->stats.cifs_stats.num_writes),
(long long)(tcon->bytes_written));
seq_printf(m, "\nFlushes: %d",
atomic_read(&tcon->stats.cifs_stats.num_flushes));
seq_printf(m, "\nLocks: %d HardLinks: %d Symlinks: %d",
atomic_read(&tcon->stats.cifs_stats.num_locks),
atomic_read(&tcon->stats.cifs_stats.num_hardlinks),
atomic_read(&tcon->stats.cifs_stats.num_symlinks));
seq_printf(m, "\nOpens: %d Closes: %d Deletes: %d",
atomic_read(&tcon->stats.cifs_stats.num_opens),
atomic_read(&tcon->stats.cifs_stats.num_closes),
atomic_read(&tcon->stats.cifs_stats.num_deletes));
seq_printf(m, "\nPosix Opens: %d Posix Mkdirs: %d",
atomic_read(&tcon->stats.cifs_stats.num_posixopens),
atomic_read(&tcon->stats.cifs_stats.num_posixmkdirs));
seq_printf(m, "\nMkdirs: %d Rmdirs: %d",
atomic_read(&tcon->stats.cifs_stats.num_mkdirs),
atomic_read(&tcon->stats.cifs_stats.num_rmdirs));
seq_printf(m, "\nRenames: %d T2 Renames %d",
atomic_read(&tcon->stats.cifs_stats.num_renames),
atomic_read(&tcon->stats.cifs_stats.num_t2renames));
seq_printf(m, "\nFindFirst: %d FNext %d FClose %d",
atomic_read(&tcon->stats.cifs_stats.num_ffirst),
atomic_read(&tcon->stats.cifs_stats.num_fnext),
atomic_read(&tcon->stats.cifs_stats.num_fclose));
#endif
}
static void
cifs_mkdir_setinfo(struct inode *inode, const char *full_path,
struct cifs_sb_info *cifs_sb, struct cifs_tcon *tcon,
const unsigned int xid)
{
FILE_BASIC_INFO info;
struct cifsInodeInfo *cifsInode;
u32 dosattrs;
int rc;
memset(&info, 0, sizeof(info));
cifsInode = CIFS_I(inode);
dosattrs = cifsInode->cifsAttrs|ATTR_READONLY;
info.Attributes = cpu_to_le32(dosattrs);
rc = CIFSSMBSetPathInfo(xid, tcon, full_path, &info, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc == 0)
cifsInode->cifsAttrs = dosattrs;
}
static int
cifs_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
__u32 *oplock, FILE_ALL_INFO *buf)
{
if (!(oparms->tcon->ses->capabilities & CAP_NT_SMBS))
return SMBLegacyOpen(xid, oparms->tcon, oparms->path,
oparms->disposition,
oparms->desired_access,
oparms->create_options,
&oparms->fid->netfid, oplock, buf,
oparms->cifs_sb->local_nls,
oparms->cifs_sb->mnt_cifs_flags
& CIFS_MOUNT_MAP_SPECIAL_CHR);
return CIFS_open(xid, oparms, oplock, buf);
}
static void
cifs_set_fid(struct cifsFileInfo *cfile, struct cifs_fid *fid, __u32 oplock)
{
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
cfile->fid.netfid = fid->netfid;
cifs_set_oplock_level(cinode, oplock);
cinode->can_cache_brlcks = CIFS_CACHE_WRITE(cinode);
}
static void
cifs_close_file(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_fid *fid)
{
CIFSSMBClose(xid, tcon, fid->netfid);
}
static int
cifs_flush_file(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_fid *fid)
{
return CIFSSMBFlush(xid, tcon, fid->netfid);
}
static int
cifs_sync_read(const unsigned int xid, struct cifsFileInfo *cfile,
struct cifs_io_parms *parms, unsigned int *bytes_read,
char **buf, int *buf_type)
{
parms->netfid = cfile->fid.netfid;
return CIFSSMBRead(xid, parms, bytes_read, buf, buf_type);
}
static int
cifs_sync_write(const unsigned int xid, struct cifsFileInfo *cfile,
struct cifs_io_parms *parms, unsigned int *written,
struct kvec *iov, unsigned long nr_segs)
{
parms->netfid = cfile->fid.netfid;
return CIFSSMBWrite2(xid, parms, written, iov, nr_segs);
}
static int
smb_set_file_info(struct inode *inode, const char *full_path,
FILE_BASIC_INFO *buf, const unsigned int xid)
{
int oplock = 0;
int rc;
__u32 netpid;
struct cifs_fid fid;
struct cifs_open_parms oparms;
struct cifsFileInfo *open_file;
struct cifsInodeInfo *cinode = CIFS_I(inode);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct tcon_link *tlink = NULL;
struct cifs_tcon *tcon;
/* if the file is already open for write, just use that fileid */
open_file = find_writable_file(cinode, true);
if (open_file) {
fid.netfid = open_file->fid.netfid;
netpid = open_file->pid;
tcon = tlink_tcon(open_file->tlink);
goto set_via_filehandle;
}
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
tlink = NULL;
goto out;
}
tcon = tlink_tcon(tlink);
rc = CIFSSMBSetPathInfo(xid, tcon, full_path, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc == 0) {
cinode->cifsAttrs = le32_to_cpu(buf->Attributes);
goto out;
} else if (rc != -EOPNOTSUPP && rc != -EINVAL) {
goto out;
}
oparms.tcon = tcon;
oparms.cifs_sb = cifs_sb;
oparms.desired_access = SYNCHRONIZE | FILE_WRITE_ATTRIBUTES;
oparms.create_options = CREATE_NOT_DIR;
oparms.disposition = FILE_OPEN;
oparms.path = full_path;
oparms.fid = &fid;
oparms.reconnect = false;
cifs_dbg(FYI, "calling SetFileInfo since SetPathInfo for times not supported by this server\n");
rc = CIFS_open(xid, &oparms, &oplock, NULL);
if (rc != 0) {
if (rc == -EIO)
rc = -EINVAL;
goto out;
}
netpid = current->tgid;
set_via_filehandle:
rc = CIFSSMBSetFileInfo(xid, tcon, buf, fid.netfid, netpid);
if (!rc)
cinode->cifsAttrs = le32_to_cpu(buf->Attributes);
if (open_file == NULL)
CIFSSMBClose(xid, tcon, fid.netfid);
else
cifsFileInfo_put(open_file);
out:
if (tlink != NULL)
cifs_put_tlink(tlink);
return rc;
}
static int
cifs_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
struct cifsFileInfo *cfile)
{
return CIFSSMB_set_compression(xid, tcon, cfile->fid.netfid);
}
static int
cifs_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon,
const char *path, struct cifs_sb_info *cifs_sb,
struct cifs_fid *fid, __u16 search_flags,
struct cifs_search_info *srch_inf)
{
return CIFSFindFirst(xid, tcon, path, cifs_sb,
&fid->netfid, search_flags, srch_inf, true);
}
static int
cifs_query_dir_next(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_fid *fid, __u16 search_flags,
struct cifs_search_info *srch_inf)
{
return CIFSFindNext(xid, tcon, fid->netfid, search_flags, srch_inf);
}
static int
cifs_close_dir(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_fid *fid)
{
return CIFSFindClose(xid, tcon, fid->netfid);
}
static int
cifs_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
struct cifsInodeInfo *cinode)
{
return CIFSSMBLock(0, tcon, fid->netfid, current->tgid, 0, 0, 0, 0,
LOCKING_ANDX_OPLOCK_RELEASE, false,
CIFS_CACHE_READ(cinode) ? 1 : 0);
}
static int
cifs_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
struct kstatfs *buf)
{
int rc = -EOPNOTSUPP;
buf->f_type = CIFS_MAGIC_NUMBER;
/*
* 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);
return rc;
}
static int
cifs_mand_lock(const unsigned int xid, struct cifsFileInfo *cfile, __u64 offset,
__u64 length, __u32 type, int lock, int unlock, bool wait)
{
return CIFSSMBLock(xid, tlink_tcon(cfile->tlink), cfile->fid.netfid,
current->tgid, length, offset, unlock, lock,
(__u8)type, wait, 0);
}
static int
cifs_unix_dfs_readlink(const unsigned int xid, struct cifs_tcon *tcon,
const unsigned char *searchName, char **symlinkinfo,
const struct nls_table *nls_codepage)
{
#ifdef CONFIG_CIFS_DFS_UPCALL
int rc;
unsigned int num_referrals = 0;
struct dfs_info3_param *referrals = NULL;
rc = get_dfs_path(xid, tcon->ses, searchName, nls_codepage,
&num_referrals, &referrals, 0);
if (!rc && num_referrals > 0) {
*symlinkinfo = kstrndup(referrals->node_name,
strlen(referrals->node_name),
GFP_KERNEL);
if (!*symlinkinfo)
rc = -ENOMEM;
free_dfs_info_array(referrals, num_referrals);
}
return rc;
#else /* No DFS support */
return -EREMOTE;
#endif
}
static int
cifs_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
const char *full_path, char **target_path,
struct cifs_sb_info *cifs_sb)
{
int rc;
int oplock = 0;
struct cifs_fid fid;
struct cifs_open_parms oparms;
cifs_dbg(FYI, "%s: path: %s\n", __func__, full_path);
/* Check for unix extensions */
if (cap_unix(tcon->ses)) {
rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, target_path,
cifs_sb->local_nls);
if (rc == -EREMOTE)
rc = cifs_unix_dfs_readlink(xid, tcon, full_path,
target_path,
cifs_sb->local_nls);
goto out;
}
oparms.tcon = tcon;
oparms.cifs_sb = cifs_sb;
oparms.desired_access = FILE_READ_ATTRIBUTES;
oparms.create_options = OPEN_REPARSE_POINT;
oparms.disposition = FILE_OPEN;
oparms.path = full_path;
oparms.fid = &fid;
oparms.reconnect = false;
rc = CIFS_open(xid, &oparms, &oplock, NULL);
if (rc)
goto out;
rc = CIFSSMBQuerySymLink(xid, tcon, fid.netfid, target_path,
cifs_sb->local_nls);
if (rc)
goto out_close;
convert_delimiter(*target_path, '/');
out_close:
CIFSSMBClose(xid, tcon, fid.netfid);
out:
if (!rc)
cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);
return rc;
}
static bool
cifs_is_read_op(__u32 oplock)
{
return oplock == OPLOCK_READ;
}
struct smb_version_operations smb1_operations = {
.send_cancel = send_nt_cancel,
.compare_fids = cifs_compare_fids,
.setup_request = cifs_setup_request,
.setup_async_request = cifs_setup_async_request,
.check_receive = cifs_check_receive,
.add_credits = cifs_add_credits,
.set_credits = cifs_set_credits,
.get_credits_field = cifs_get_credits_field,
.get_credits = cifs_get_credits,
.get_next_mid = cifs_get_next_mid,
.read_data_offset = cifs_read_data_offset,
.read_data_length = cifs_read_data_length,
.map_error = map_smb_to_linux_error,
.find_mid = cifs_find_mid,
.check_message = checkSMB,
.dump_detail = cifs_dump_detail,
.clear_stats = cifs_clear_stats,
.print_stats = cifs_print_stats,
.is_oplock_break = is_valid_oplock_break,
cifs: Wait for writebacks to complete before attempting write. Problem reported in Red Hat bz 1040329 for strict writes where we cache only when we hold oplock and write direct to the server when we don't. When we receive an oplock break, we first change the oplock value for the inode in cifsInodeInfo->oplock to indicate that we no longer hold the oplock before we enqueue a task to flush changes to the backing device. Once we have completed flushing the changes, we return the oplock to the server. There are 2 ways here where we can have data corruption 1) While we flush changes to the backing device as part of the oplock break, we can have processes write to the file. These writes check for the oplock, find none and attempt to write directly to the server. These direct writes made while we are flushing from cache could be overwritten by data being flushed from the cache causing data corruption. 2) While a thread runs in cifs_strict_writev, the machine could receive and process an oplock break after the thread has checked the oplock and found that it allows us to cache and before we have made changes to the cache. In that case, we end up with a dirty page in cache when we shouldn't have any. This will be flushed later and will overwrite all subsequent writes to the part of the file represented by this page. Before making any writes to the server, we need to confirm that we are not in the process of flushing data to the server and if we are, we should wait until the process is complete before we attempt the write. We should also wait for existing writes to complete before we process an oplock break request which changes oplock values. We add a version specific downgrade_oplock() operation to allow for differences in the oplock values set for the different smb versions. Cc: stable@vger.kernel.org Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Steve French <smfrench@gmail.com>
2014-03-11 16:11:47 +00:00
.downgrade_oplock = cifs_downgrade_oplock,
.check_trans2 = cifs_check_trans2,
.need_neg = cifs_need_neg,
.negotiate = cifs_negotiate,
.negotiate_wsize = cifs_negotiate_wsize,
.negotiate_rsize = cifs_negotiate_rsize,
.sess_setup = CIFS_SessSetup,
.logoff = CIFSSMBLogoff,
.tree_connect = CIFSTCon,
.tree_disconnect = CIFSSMBTDis,
.get_dfs_refer = CIFSGetDFSRefer,
.qfs_tcon = cifs_qfs_tcon,
.is_path_accessible = cifs_is_path_accessible,
.query_path_info = cifs_query_path_info,
.query_file_info = cifs_query_file_info,
.get_srv_inum = cifs_get_srv_inum,
.set_path_size = CIFSSMBSetEOF,
.set_file_size = CIFSSMBSetFileSize,
.set_file_info = smb_set_file_info,
.set_compression = cifs_set_compression,
.echo = CIFSSMBEcho,
.mkdir = CIFSSMBMkDir,
.mkdir_setinfo = cifs_mkdir_setinfo,
.rmdir = CIFSSMBRmDir,
.unlink = CIFSSMBDelFile,
.rename_pending_delete = cifs_rename_pending_delete,
.rename = CIFSSMBRename,
.create_hardlink = CIFSCreateHardLink,
.query_symlink = cifs_query_symlink,
.open = cifs_open_file,
.set_fid = cifs_set_fid,
.close = cifs_close_file,
.flush = cifs_flush_file,
.async_readv = cifs_async_readv,
.async_writev = cifs_async_writev,
.sync_read = cifs_sync_read,
.sync_write = cifs_sync_write,
.query_dir_first = cifs_query_dir_first,
.query_dir_next = cifs_query_dir_next,
.close_dir = cifs_close_dir,
.calc_smb_size = smbCalcSize,
.oplock_response = cifs_oplock_response,
.queryfs = cifs_queryfs,
.mand_lock = cifs_mand_lock,
.mand_unlock_range = cifs_unlock_range,
.push_mand_locks = cifs_push_mandatory_locks,
.query_mf_symlink = cifs_query_mf_symlink,
.create_mf_symlink = cifs_create_mf_symlink,
.is_read_op = cifs_is_read_op,
#ifdef CONFIG_CIFS_XATTR
.query_all_EAs = CIFSSMBQAllEAs,
.set_EA = CIFSSMBSetEA,
#endif /* CIFS_XATTR */
#ifdef CONFIG_CIFS_ACL
.get_acl = get_cifs_acl,
2014-02-10 20:08:16 +00:00
.get_acl_by_fid = get_cifs_acl_by_fid,
.set_acl = set_cifs_acl,
#endif /* CIFS_ACL */
};
struct smb_version_values smb1_values = {
.version_string = SMB1_VERSION_STRING,
.large_lock_type = LOCKING_ANDX_LARGE_FILES,
.exclusive_lock_type = 0,
.shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
.unlock_lock_type = 0,
.header_size = sizeof(struct smb_hdr),
.max_header_size = MAX_CIFS_HDR_SIZE,
.read_rsp_size = sizeof(READ_RSP),
.lock_cmd = cpu_to_le16(SMB_COM_LOCKING_ANDX),
.cap_unix = CAP_UNIX,
.cap_nt_find = CAP_NT_SMBS | CAP_NT_FIND,
.cap_large_files = CAP_LARGE_FILES,
.signing_enabled = SECMODE_SIGN_ENABLED,
.signing_required = SECMODE_SIGN_REQUIRED,
};