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authorSteve French <stfrench@microsoft.com>2023-06-19 22:32:38 -0500
committerSteve French <stfrench@microsoft.com>2023-06-20 23:03:03 -0500
commite8eeca0bf4466ee1b196346d3a247535990cf44d (patch)
treeb7b5358e1466a0dd3cfb3a0b5f8668dfabf39027 /fs/smb
parentacf35d79ee8c1cce0f879efe6446cf81e5491c36 (diff)
smb3: do not reserve too many oplock credits
There were cases reported where servers will sometimes return more credits than requested on oplock break responses, which can lead to most of the credits being allocated for oplock breaks (instead of for normal operations like read and write) if number of SMB3 requests in flight always stays above 0 (the oplock and echo credits are rebalanced when in flight requests goes down to zero). If oplock credits gets unexpectedly large (e.g. three is more than it would ever be expected to be) and in flight requests are greater than zero, then rebalance the oplock credits and regular credits (go back to reserving just one oplock credit). Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb')
-rw-r--r--fs/smb/client/smb2ops.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index a8bb9d00d33a..1dc2143ae924 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -109,7 +109,11 @@ smb2_add_credits(struct TCP_Server_Info *server,
server->credits--;
server->oplock_credits++;
}
- }
+ } else if ((server->in_flight > 0) && (server->oplock_credits > 3) &&
+ ((optype & CIFS_OP_MASK) == CIFS_OBREAK_OP))
+ /* if now have too many oplock credits, rebalance so don't starve normal ops */
+ change_conf(server);
+
scredits = *val;
in_flight = server->in_flight;
spin_unlock(&server->req_lock);