Signed-off-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
---
fs/cifs/cifsglob.h | 7 ++++
fs/cifs/cifsproto.h | 1 -
fs/cifs/cifssmb.c | 8 ++--
fs/cifs/connect.c | 2 +-
fs/cifs/misc.c | 89 +--------------------------------------------------
fs/cifs/smb1ops.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/transport.c | 2 +-
7 files changed, 103 insertions(+), 95 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 48d1009..a660577 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -174,6 +174,7 @@ struct smb_version_operations {
void (*add_credits)(struct TCP_Server_Info *, const unsigned int);
void (*set_credits)(struct TCP_Server_Info *, const int);
int * (*get_credits_field)(struct TCP_Server_Info *);
+ __u64 (*get_next_mid)(struct TCP_Server_Info *);
/* data offset from read response message */
unsigned int (*read_data_offset)(char *);
/* data length from read response message */
@@ -417,6 +418,12 @@ set_credits(struct TCP_Server_Info *server, const int val)
server->ops->set_credits(server, val);
}
+static inline __u64
+get_next_mid(struct TCP_Server_Info *server)
+{
+ return server->ops->get_next_mid(server);
+}
+
/*
* Macros to allow the TCP_Server_Info->net field and related code to drop out
* when CONFIG_NET_NS isn't set.
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 5ec21ec..0a6cbfe 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -114,7 +114,6 @@ extern int small_smb_init_no_tc(const int smb_cmd, const int wct,
void **request_buf);
extern int CIFS_SessSetup(unsigned int xid, struct cifs_ses *ses,
const struct nls_table *nls_cp);
-extern __u64 GetNextMid(struct TCP_Server_Info *server);
extern struct timespec cifs_NTtimeToUnix(__le64 utc_nanoseconds_since_1601);
extern u64 cifs_UnixTimeToNT(struct timespec);
extern struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index b5ad716..5b40073 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -268,7 +268,7 @@ small_smb_init_no_tc(const int smb_command, const int wct,
return rc;
buffer = (struct smb_hdr *)*request_buf;
- buffer->Mid = GetNextMid(ses->server);
+ buffer->Mid = get_next_mid(ses->server);
if (ses->capabilities & CAP_UNICODE)
buffer->Flags2 |= SMBFLG2_UNICODE;
if (ses->capabilities & CAP_STATUS32)
@@ -402,7 +402,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses)
cFYI(1, "secFlags 0x%x", secFlags);
- pSMB->hdr.Mid = GetNextMid(server);
+ pSMB->hdr.Mid = get_next_mid(server);
pSMB->hdr.Flags2 |= (SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS);
if ((secFlags & CIFSSEC_MUST_KRB5) == CIFSSEC_MUST_KRB5)
@@ -782,7 +782,7 @@ CIFSSMBLogoff(const int xid, struct cifs_ses *ses)
return rc;
}
- pSMB->hdr.Mid = GetNextMid(ses->server);
+ pSMB->hdr.Mid = get_next_mid(ses->server);
if (ses->server->sec_mode &
(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
@@ -4762,7 +4762,7 @@ getDFSRetry:
/* server pointer checked in called function,
but should never be null here anyway */
- pSMB->hdr.Mid = GetNextMid(ses->server);
+ pSMB->hdr.Mid = get_next_mid(ses->server);
pSMB->hdr.Tid = ses->ipc_tid;
pSMB->hdr.Uid = ses->Suid;
if (ses->capabilities & CAP_STATUS32)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a849aca..9362f90 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3938,7 +3938,7 @@ CIFSTCon(unsigned int xid, struct cifs_ses *ses,
header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
NULL /*no tid */ , 4 /*wct */ );
- smb_buffer->Mid = GetNextMid(ses->server);
+ smb_buffer->Mid = get_next_mid(ses->server);
smb_buffer->Uid = ses->Suid;
pSMB = (TCONX_REQ *) smb_buffer;
pSMBr = (TCONX_RSP *) smb_buffer_response;
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index e2552d2..557506a 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -212,93 +212,6 @@ cifs_small_buf_release(void *buf_to_free)
return;
}
-/*
- * 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.
- */
-__u64 GetNextMid(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;
-}
-
/* NB: MID can not be set if treeCon not passed in, in that
case it is responsbility of caller to set the mid */
void
@@ -334,7 +247,7 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
/* Uid is not converted */
buffer->Uid = treeCon->ses->Suid;
- buffer->Mid = GetNextMid(treeCon->ses->server);
+ buffer->Mid = get_next_mid(treeCon->ses->server);
}
if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
buffer->Flags2 |= SMBFLG2_DFS;
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index d9d615f..6dec38f 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -125,6 +125,94 @@ cifs_get_credits_field(struct TCP_Server_Info *server)
return &server->credits;
}
+/*
+ * 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;
+}
+
struct smb_version_operations smb1_operations = {
.send_cancel = send_nt_cancel,
.compare_fids = cifs_compare_fids,
@@ -133,6 +221,7 @@ struct smb_version_operations smb1_operations = {
.add_credits = cifs_add_credits,
.set_credits = cifs_set_credits,
.get_credits_field = cifs_get_credits_field,
+ .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,
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 81d68f4..6fdb5be 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -778,7 +778,7 @@ send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
pSMB->Timeout = 0;
- pSMB->hdr.Mid = GetNextMid(ses->server);
+ pSMB->hdr.Mid = get_next_mid(ses->server);
return SendReceive(xid, ses, in_buf, out_buf,
&bytes_returned, 0);
--
1.7.1
--
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