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-rw-r--r--fs/cifs/cifs_debug.c2
-rw-r--r--fs/cifs/cifsglob.h5
-rw-r--r--fs/cifs/connect.c25
-rw-r--r--fs/cifs/misc.c1
-rw-r--r--fs/cifs/sess.c50
-rw-r--r--fs/cifs/transport.c3
6 files changed, 71 insertions, 15 deletions
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 905a901f7f80..248a8f973cf9 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -414,12 +414,14 @@ skip_rdma:
from_kuid(&init_user_ns, ses->linux_uid),
from_kuid(&init_user_ns, ses->cred_uid));
+ spin_lock(&ses->chan_lock);
if (ses->chan_count > 1) {
seq_printf(m, "\n\n\tExtra Channels: %zu ",
ses->chan_count-1);
for (j = 1; j < ses->chan_count; j++)
cifs_dump_channel(m, j, &ses->chans[j]);
}
+ spin_unlock(&ses->chan_lock);
seq_puts(m, "\n\n\tShares: ");
j = 0;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 673ecbfe6d9a..3c18c56a119b 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -952,16 +952,21 @@ struct cifs_ses {
* iface_lock should be taken when accessing any of these fields
*/
spinlock_t iface_lock;
+ /* ========= begin: protected by iface_lock ======== */
struct cifs_server_iface *iface_list;
size_t iface_count;
unsigned long iface_last_update; /* jiffies */
+ /* ========= end: protected by iface_lock ======== */
+ spinlock_t chan_lock;
+ /* ========= begin: protected by chan_lock ======== */
#define CIFS_MAX_CHANNELS 16
struct cifs_chan chans[CIFS_MAX_CHANNELS];
struct cifs_chan *binding_chan;
size_t chan_count;
size_t chan_max;
atomic_t chan_seq; /* round robin state */
+ /* ========= end: protected by chan_lock ======== */
};
/*
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 498ec05ca10d..09a532ed8fe4 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1577,8 +1577,12 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
* If an existing session is limited to less channels than
* requested, it should not be reused
*/
- if (ses->chan_max < ctx->max_channels)
+ spin_lock(&ses->chan_lock);
+ if (ses->chan_max < ctx->max_channels) {
+ spin_unlock(&ses->chan_lock);
return 0;
+ }
+ spin_unlock(&ses->chan_lock);
switch (ses->sectype) {
case Kerberos:
@@ -1713,6 +1717,7 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
void cifs_put_smb_ses(struct cifs_ses *ses)
{
unsigned int rc, xid;
+ unsigned int chan_count;
struct TCP_Server_Info *server = ses->server;
cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
@@ -1754,12 +1759,24 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
list_del_init(&ses->smb_ses_list);
spin_unlock(&cifs_tcp_ses_lock);
+ spin_lock(&ses->chan_lock);
+ chan_count = ses->chan_count;
+ spin_unlock(&ses->chan_lock);
+
/* close any extra channels */
- if (ses->chan_count > 1) {
+ if (chan_count > 1) {
int i;
- for (i = 1; i < ses->chan_count; i++)
+ for (i = 1; i < chan_count; i++) {
+ /*
+ * note: for now, we're okay accessing ses->chans
+ * without chan_lock. But when chans can go away, we'll
+ * need to introduce ref counting to make sure that chan
+ * is not freed from under us.
+ */
cifs_put_tcp_session(ses->chans[i].server, 0);
+ ses->chans[i].server = NULL;
+ }
}
sesInfoFree(ses);
@@ -2018,9 +2035,11 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
mutex_lock(&ses->session_mutex);
/* add server as first channel */
+ spin_lock(&ses->chan_lock);
ses->chans[0].server = server;
ses->chan_count = 1;
ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
+ spin_unlock(&ses->chan_lock);
rc = cifs_negotiate_protocol(xid, ses);
if (!rc)
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index a6089ea53ad7..5148d48d6a35 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -75,6 +75,7 @@ sesInfoAlloc(void)
INIT_LIST_HEAD(&ret_buf->tcon_list);
mutex_init(&ret_buf->session_mutex);
spin_lock_init(&ret_buf->iface_lock);
+ spin_lock_init(&ret_buf->chan_lock);
}
return ret_buf;
}
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 93a1619d60e6..27660bffb918 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -54,41 +54,53 @@ bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
{
int i;
+ spin_lock(&ses->chan_lock);
for (i = 0; i < ses->chan_count; i++) {
- if (is_server_using_iface(ses->chans[i].server, iface))
+ if (is_server_using_iface(ses->chans[i].server, iface)) {
+ spin_unlock(&ses->chan_lock);
return true;
+ }
}
+ spin_unlock(&ses->chan_lock);
return false;
}
/* returns number of channels added */
int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
{
- int old_chan_count = ses->chan_count;
- int left = ses->chan_max - ses->chan_count;
+ int old_chan_count, new_chan_count;
+ int left;
int i = 0;
int rc = 0;
int tries = 0;
struct cifs_server_iface *ifaces = NULL;
size_t iface_count;
+ if (ses->server->dialect < SMB30_PROT_ID) {
+ cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
+ return 0;
+ }
+
+ spin_lock(&ses->chan_lock);
+
+ new_chan_count = old_chan_count = ses->chan_count;
+ left = ses->chan_max - ses->chan_count;
+
if (left <= 0) {
cifs_dbg(FYI,
"ses already at max_channels (%zu), nothing to open\n",
ses->chan_max);
- return 0;
- }
-
- if (ses->server->dialect < SMB30_PROT_ID) {
- cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
+ spin_unlock(&ses->chan_lock);
return 0;
}
if (!(ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
cifs_dbg(VFS, "server %s does not support multichannel\n", ses->server->hostname);
ses->chan_max = 1;
+ spin_unlock(&ses->chan_lock);
return 0;
}
+ spin_unlock(&ses->chan_lock);
/*
* Make a copy of the iface list at the time and use that
@@ -142,10 +154,11 @@ int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
cifs_dbg(FYI, "successfully opened new channel on iface#%d\n",
i);
left--;
+ new_chan_count++;
}
kfree(ifaces);
- return ses->chan_count - old_chan_count;
+ return new_chan_count - old_chan_count;
}
/*
@@ -157,10 +170,14 @@ cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
{
int i;
+ spin_lock(&ses->chan_lock);
for (i = 0; i < ses->chan_count; i++) {
- if (ses->chans[i].server == server)
+ if (ses->chans[i].server == server) {
+ spin_unlock(&ses->chan_lock);
return &ses->chans[i];
+ }
}
+ spin_unlock(&ses->chan_lock);
return NULL;
}
@@ -168,6 +185,7 @@ static int
cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
struct cifs_server_iface *iface)
{
+ struct TCP_Server_Info *chan_server;
struct cifs_chan *chan;
struct smb3_fs_context ctx = {NULL};
static const char unc_fmt[] = "\\%s\\foo";
@@ -240,15 +258,20 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
SMB2_CLIENT_GUID_SIZE);
ctx.use_client_guid = true;
- mutex_lock(&ses->session_mutex);
+ chan_server = cifs_get_tcp_session(&ctx);
+ mutex_lock(&ses->session_mutex);
+ spin_lock(&ses->chan_lock);
chan = ses->binding_chan = &ses->chans[ses->chan_count];
- chan->server = cifs_get_tcp_session(&ctx);
+ chan->server = chan_server;
if (IS_ERR(chan->server)) {
rc = PTR_ERR(chan->server);
chan->server = NULL;
+ spin_unlock(&ses->chan_lock);
goto out;
}
+ spin_unlock(&ses->chan_lock);
+
spin_lock(&cifs_tcp_ses_lock);
chan->server->is_channel = true;
spin_unlock(&cifs_tcp_ses_lock);
@@ -283,8 +306,11 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
* ses to the new server.
*/
+ spin_lock(&ses->chan_lock);
ses->chan_count++;
atomic_set(&ses->chan_seq, 0);
+ spin_unlock(&ses->chan_lock);
+
out:
ses->binding = false;
ses->binding_chan = NULL;
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index b7379329b741..61ea3d3f95b4 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -1044,14 +1044,17 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
if (!ses)
return NULL;
+ spin_lock(&ses->chan_lock);
if (!ses->binding) {
/* round robin */
if (ses->chan_count > 1) {
index = (uint)atomic_inc_return(&ses->chan_seq);
index %= ses->chan_count;
}
+ spin_unlock(&ses->chan_lock);
return ses->chans[index].server;
} else {
+ spin_unlock(&ses->chan_lock);
return cifs_ses_server(ses);
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-12 09:59:45 +0000