diff options
| author | Pavel Shilovsky <pshilovsky@samba.org> | 2014-06-05 19:03:27 +0400 |
|---|---|---|
| committer | Steve French <smfrench@gmail.com> | 2014-08-02 01:23:03 -0500 |
| commit | cb7e9eabb2b584884db0d11ae0376d31ac1cfdc1 (patch) | |
| tree | 4f6fd78f74b173359dd673b8bf49b8f188aab0be /fs/cifs/smb2ops.c | |
| parent | 6ec0b01b2691d1465bb7219e031e8bf38ccd9397 (diff) | |
| download | linux-cb7e9eabb2b584884db0d11ae0376d31ac1cfdc1.tar.bz2 | |
CIFS: Use multicredits for SMB 2.1/3 writes
If we negotiate SMB 2.1 and higher version of the protocol and
a server supports large write buffer size, we need to consume 1
credit per 65536 bytes. So, we need to know how many credits
we have and obtain the required number of them before constructing
a writedata structure in writepages and iovec write.
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs/smb2ops.c')
| -rw-r--r-- | fs/cifs/smb2ops.c | 55 |
1 files changed, 53 insertions, 2 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index e35ce5b3d88f..3427c1fa3806 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -112,6 +112,53 @@ smb2_get_credits(struct mid_q_entry *mid) return le16_to_cpu(((struct smb2_hdr *)mid->resp_buf)->CreditRequest); } +static int +smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size, + unsigned int *num, unsigned int *credits) +{ + int rc = 0; + unsigned int scredits; + + spin_lock(&server->req_lock); + while (1) { + if (server->credits <= 0) { + spin_unlock(&server->req_lock); + cifs_num_waiters_inc(server); + rc = wait_event_killable(server->request_q, + has_credits(server, &server->credits)); + cifs_num_waiters_dec(server); + if (rc) + return rc; + spin_lock(&server->req_lock); + } else { + if (server->tcpStatus == CifsExiting) { + spin_unlock(&server->req_lock); + return -ENOENT; + } + + scredits = server->credits; + /* can deadlock with reopen */ + if (scredits == 1) { + *num = SMB2_MAX_BUFFER_SIZE; + *credits = 0; + break; + } + + /* leave one credit for a possible reopen */ + scredits--; + *num = min_t(unsigned int, size, + scredits * SMB2_MAX_BUFFER_SIZE); + + *credits = DIV_ROUND_UP(*num, SMB2_MAX_BUFFER_SIZE); + server->credits -= *credits; + server->in_flight++; + break; + } + } + spin_unlock(&server->req_lock); + return rc; +} + static __u64 smb2_get_next_mid(struct TCP_Server_Info *server) { @@ -182,8 +229,9 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info) /* start with specified wsize, or default */ wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE; wsize = min_t(unsigned int, wsize, server->max_write); - /* set it to the maximum buffer size value we can send with 1 credit */ - wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE); + + if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU)) + wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE); return wsize; } @@ -1120,6 +1168,7 @@ struct smb_version_operations smb20_operations = { .set_credits = smb2_set_credits, .get_credits_field = smb2_get_credits_field, .get_credits = smb2_get_credits, + .wait_mtu_credits = cifs_wait_mtu_credits, .get_next_mid = smb2_get_next_mid, .read_data_offset = smb2_read_data_offset, .read_data_length = smb2_read_data_length, @@ -1196,6 +1245,7 @@ struct smb_version_operations smb21_operations = { .set_credits = smb2_set_credits, .get_credits_field = smb2_get_credits_field, .get_credits = smb2_get_credits, + .wait_mtu_credits = smb2_wait_mtu_credits, .get_next_mid = smb2_get_next_mid, .read_data_offset = smb2_read_data_offset, .read_data_length = smb2_read_data_length, @@ -1272,6 +1322,7 @@ struct smb_version_operations smb30_operations = { .set_credits = smb2_set_credits, .get_credits_field = smb2_get_credits_field, .get_credits = smb2_get_credits, + .wait_mtu_credits = smb2_wait_mtu_credits, .get_next_mid = smb2_get_next_mid, .read_data_offset = smb2_read_data_offset, .read_data_length = smb2_read_data_length, |