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CIFS: Use multicredits for SMB 2.1/3 writes

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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>
This commit is contained in:
Pavel Shilovsky 2014-06-05 19:03:27 +04:00 committed by Steve French
parent 6ec0b01b26
commit cb7e9eabb2
8 changed files with 150 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
fs/cifs/cifsglob.h
View File

@ -406,6 +406,9 @@ struct smb_version_operations {
int);
/* writepages retry size */
unsigned int (*wp_retry_size)(struct inode *);
/* get mtu credits */
int (*wait_mtu_credits)(struct TCP_Server_Info *, unsigned int,
unsigned int *, unsigned int *);
};
struct smb_version_values {
@ -641,6 +644,16 @@ add_credits(struct TCP_Server_Info *server, const unsigned int add,
server->ops->add_credits(server, add, optype);
}
static inline void
add_credits_and_wake_if(struct TCP_Server_Info *server, const unsigned int add,
const int optype)
{
if (add) {
server->ops->add_credits(server, add, optype);
wake_up(&server->request_q);
}
}
static inline void
set_credits(struct TCP_Server_Info *server, const int val)
{
@ -1075,6 +1088,7 @@ struct cifs_writedata {
int result;
unsigned int pagesz;
unsigned int tailsz;
unsigned int credits;
unsigned int nr_pages;
struct page *pages[];
};
@ -1400,6 +1414,7 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param,
#define CIFS_OBREAK_OP 0x0100 /* oplock break request */
#define CIFS_NEG_OP 0x0200 /* negotiate request */
#define CIFS_OP_MASK 0x0380 /* mask request type */
#define CIFS_HAS_CREDITS 0x0400 /* already has credits */
/* Security Flags: indicate type of session setup needed */
#define CIFSSEC_MAY_SIGN 0x00001

3
fs/cifs/cifsproto.h
View File

@ -90,6 +90,9 @@ extern struct mid_q_entry *cifs_setup_async_request(struct TCP_Server_Info *,
struct smb_rqst *);
extern int cifs_check_receive(struct mid_q_entry *mid,
struct TCP_Server_Info *server, bool log_error);
extern int cifs_wait_mtu_credits(struct TCP_Server_Info *server,
unsigned int size, unsigned int *num,
unsigned int *credits);
extern int SendReceive2(const unsigned int /* xid */ , struct cifs_ses *,
struct kvec *, int /* nvec to send */,
int * /* type of buf returned */ , const int flags);

36
fs/cifs/file.c
View File

@ -1670,8 +1670,8 @@ cifs_write(struct cifsFileInfo *open_file, __u32 pid, const char *write_data,
break;
}
len = min((size_t)cifs_sb->wsize,
write_size - total_written);
len = min(server->ops->wp_retry_size(dentry->d_inode),
(unsigned int)write_size - total_written);
/* iov[0] is reserved for smb header */
iov[1].iov_base = (char *)write_data + total_written;
iov[1].iov_len = len;
@ -2031,6 +2031,7 @@ static int cifs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb);
struct TCP_Server_Info *server;
bool done = false, scanned = false, range_whole = false;
pgoff_t end, index;
struct cifs_writedata *wdata;
@ -2053,23 +2054,30 @@ static int cifs_writepages(struct address_space *mapping,
range_whole = true;
scanned = true;
}
server = cifs_sb_master_tcon(cifs_sb)->ses->server;
retry:
while (!done && index <= end) {
unsigned int i, nr_pages, found_pages;
unsigned int i, nr_pages, found_pages, wsize, credits;
pgoff_t next = 0, tofind, saved_index = index;
tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1,
end - index) + 1;
rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
&wsize, &credits);
if (rc)
break;
tofind = min((wsize / PAGE_CACHE_SIZE) - 1, end - index) + 1;
wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
&found_pages);
if (!wdata) {
rc = -ENOMEM;
add_credits_and_wake_if(server, credits, 0);
break;
}
if (found_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
add_credits_and_wake_if(server, credits, 0);
break;
}
@ -2079,13 +2087,17 @@ retry:
/* nothing to write? */
if (nr_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
add_credits_and_wake_if(server, credits, 0);
continue;
}
wdata->credits = credits;
rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
/* send failure -- clean up the mess */
if (rc != 0) {
add_credits_and_wake_if(server, wdata->credits, 0);
for (i = 0; i < nr_pages; ++i) {
if (rc == -EAGAIN)
redirty_page_for_writepage(wbc,
@ -2466,17 +2478,26 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
memcpy(&saved_from, from, sizeof(struct iov_iter));
do {
nr_pages = get_numpages(cifs_sb->wsize, len, &cur_len);
unsigned int wsize, credits;
rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
&wsize, &credits);
if (rc)
break;
nr_pages = get_numpages(wsize, len, &cur_len);
wdata = cifs_writedata_alloc(nr_pages,
cifs_uncached_writev_complete);
if (!wdata) {
rc = -ENOMEM;
add_credits_and_wake_if(server, credits, 0);
break;
}
rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
if (rc) {
kfree(wdata);
add_credits_and_wake_if(server, credits, 0);
break;
}
@ -2486,6 +2507,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
for (i = 0; i < nr_pages; i++)
put_page(wdata->pages[i]);
kfree(wdata);
add_credits_and_wake_if(server, credits, 0);
break;
}
@ -2504,12 +2526,14 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
wdata->bytes = cur_len;
wdata->pagesz = PAGE_SIZE;
wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE);
wdata->credits = credits;
if (!wdata->cfile->invalidHandle ||
!cifs_reopen_file(wdata->cfile, false))
rc = server->ops->async_writev(wdata,
cifs_uncached_writedata_release);
if (rc) {
add_credits_and_wake_if(server, wdata->credits, 0);
kref_put(&wdata->refcount,
cifs_uncached_writedata_release);
if (rc == -EAGAIN) {

1
fs/cifs/smb1ops.c
View File

@ -1025,6 +1025,7 @@ struct smb_version_operations smb1_operations = {
.set_credits = cifs_set_credits,
.get_credits_field = cifs_get_credits_field,
.get_credits = cifs_get_credits,
.wait_mtu_credits = cifs_wait_mtu_credits,
.get_next_mid = cifs_get_next_mid,
.read_data_offset = cifs_read_data_offset,
.read_data_length = cifs_read_data_length,

53
fs/cifs/smb2ops.c
View File

@ -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)
{
@ -182,7 +229,8 @@ 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 */
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,

30
fs/cifs/smb2pdu.c
View File

@ -108,7 +108,6 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
if (!tcon)
goto out;
/* BB FIXME when we do write > 64K add +1 for every 64K in req or rsp */
/* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */
/* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */
if ((tcon->ses) &&
@ -1892,15 +1891,25 @@ int
smb2_async_writev(struct cifs_writedata *wdata,
void (*release)(struct kref *kref))
{
int rc = -EACCES;
int rc = -EACCES, flags = 0;
struct smb2_write_req *req = NULL;
struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink);
struct TCP_Server_Info *server = tcon->ses->server;
struct kvec iov;
struct smb_rqst rqst;
rc = small_smb2_init(SMB2_WRITE, tcon, (void **) &req);
if (rc)
if (rc) {
if (rc == -EAGAIN && wdata->credits) {
/* credits was reset by reconnect */
wdata->credits = 0;
/* reduce in_flight value since we won't send the req */
spin_lock(&server->req_lock);
server->in_flight--;
spin_unlock(&server->req_lock);
}
goto async_writev_out;
}
req->hdr.ProcessId = cpu_to_le32(wdata->cfile->pid);
@ -1933,9 +1942,20 @@ smb2_async_writev(struct cifs_writedata *wdata,
inc_rfc1001_len(&req->hdr, wdata->bytes - 1 /* Buffer */);
if (wdata->credits) {
req->hdr.CreditCharge = cpu_to_le16(DIV_ROUND_UP(wdata->bytes,
SMB2_MAX_BUFFER_SIZE));
spin_lock(&server->req_lock);
server->credits += wdata->credits -
le16_to_cpu(req->hdr.CreditCharge);
spin_unlock(&server->req_lock);
wake_up(&server->request_q);
flags = CIFS_HAS_CREDITS;
}
kref_get(&wdata->refcount);
rc = cifs_call_async(tcon->ses->server, &rqst, NULL,
smb2_writev_callback, wdata, 0);
rc = cifs_call_async(server, &rqst, NULL, smb2_writev_callback, wdata,
flags);
if (rc) {
kref_put(&wdata->refcount, release);

5
fs/cifs/smb2transport.c
View File

@ -466,7 +466,12 @@ smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
{
unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
hdr->MessageId = get_next_mid64(server);
/* skip message numbers according to CreditCharge field */
for (i = 1; i < num; i++)
get_next_mid(server);
}
static struct mid_q_entry *

19
fs/cifs/transport.c
View File

@ -448,6 +448,15 @@ wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
return wait_for_free_credits(server, timeout, val);
}
int
cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
unsigned int *num, unsigned int *credits)
{
*num = size;
*credits = 0;
return 0;
}
static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
struct mid_q_entry **ppmidQ)
{
@ -531,20 +540,23 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
{
int rc, timeout, optype;
struct mid_q_entry *mid;
unsigned int credits = 0;
timeout = flags & CIFS_TIMEOUT_MASK;
optype = flags & CIFS_OP_MASK;
if ((flags & CIFS_HAS_CREDITS) == 0) {
rc = wait_for_free_request(server, timeout, optype);
if (rc)
return rc;
credits = 1;
}
mutex_lock(&server->srv_mutex);
mid = server->ops->setup_async_request(server, rqst);
if (IS_ERR(mid)) {
mutex_unlock(&server->srv_mutex);
add_credits(server, 1, optype);
wake_up(&server->request_q);
add_credits_and_wake_if(server, credits, optype);
return PTR_ERR(mid);
}
@ -572,8 +584,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
return 0;
cifs_delete_mid(mid);
add_credits(server, 1, optype);
wake_up(&server->request_q);
add_credits_and_wake_if(server, credits, optype);
return rc;
}