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authorSteve French2016-09-23 07:44:16 +0200
committerSteve French2016-10-12 19:08:33 +0200
commit141891f4727c08829755be6c785e125d2e96c899 (patch)
treed2c32b7875356357062a0ab67044a4ae7287b689 /fs/cifs/smb2ops.c
parentfs/cifs: reopen persistent handles on reconnect (diff)
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SMB3: Add mount parameter to allow user to override max credits
Add mount option "max_credits" to allow setting maximum SMB3 credits to any value from 10 to 64000 (default is 32000). This can be useful to workaround servers with problems allocating credits, or to throttle the client to use smaller amount of simultaneous i/o or to workaround server performance issues. Also adds a cap, so that even if the server granted us more than 65000 credits due to a server bug, we would not use that many. Signed-off-by: Steve French <steve.french@primarydata.com>
Diffstat (limited to 'fs/cifs/smb2ops.c')
-rw-r--r--fs/cifs/smb2ops.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 91e53df4e420..378260cd25a6 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -70,6 +70,10 @@ smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
spin_lock(&server->req_lock);
val = server->ops->get_credits_field(server, optype);
*val += add;
+ if (*val > 65000) {
+ *val = 65000; /* Don't get near 64K credits, avoid srv bugs */
+ printk_once(KERN_WARNING "server overflowed SMB3 credits\n");
+ }
server->in_flight--;
if (server->in_flight == 0 && (optype & CIFS_OP_MASK) != CIFS_NEG_OP)
rc = change_conf(server);