If we negotiate SMB2.1 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.
Signed-off-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
---
fs/cifs/cifsglob.h | 15 ++++++++++++++
fs/cifs/cifsproto.h | 3 +++
fs/cifs/file.c | 34 +++++++++++++++++++++++++++----
fs/cifs/smb1ops.c | 1 +
fs/cifs/smb2ops.c | 52 +++++++++++++++++++++++++++++++++++++++++++++--
fs/cifs/smb2pdu.c | 24 ++++++++++++++++++----
fs/cifs/smb2transport.c | 5 +++++
fs/cifs/transport.c | 25 ++++++++++++++++-------
8 files changed, 142 insertions(+), 17 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 8c53f20..95d6867 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -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 {
@@ -642,6 +645,16 @@ add_credits(struct TCP_Server_Info *server, const unsigned int add,
}
static inline void
+add_credits_and_wake(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)
{
server->ops->set_credits(server, 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
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index ca7980a..009e5cb 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -89,6 +89,9 @@ 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);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 4ba59cd..d8ff8b6 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2046,6 +2046,7 @@ 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;
@@ -2068,23 +2069,30 @@ 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 nr_pages, found_pages;
+ unsigned int 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(server, credits, 0);
break;
}
if (found_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake(server, credits, 0);
break;
}
@@ -2094,10 +2102,16 @@ retry:
/* nothing to write? */
if (nr_pages == 0) {
kref_put(&wdata->refcount, cifs_writedata_release);
+ add_credits_and_wake(server, credits, 0);
continue;
}
+ wdata->credits = credits;
+
rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
+ if (rc)
+ add_credits_and_wake(server, wdata->credits, 0);
+
kref_put(&wdata->refcount, cifs_writedata_release);
if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
@@ -2473,17 +2487,26 @@ cifs_write_from_iovec(loff_t offset, size_t len, const struct iovec *iov,
iov_iter_init(&it, iov, nr_segs, len, written);
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(server, credits, 0);
break;
}
rc = cifs_write_allocate_pages(wdata->pages, nr_pages);
if (rc) {
kfree(wdata);
+ add_credits_and_wake(server, credits, 0);
break;
}
@@ -2492,6 +2515,7 @@ cifs_write_from_iovec(loff_t offset, size_t len, const struct iovec *iov,
for (i = 0; i < nr_pages; i++)
put_page(wdata->pages[i]);
kfree(wdata);
+ add_credits_and_wake(server, credits, 0);
break;
}
@@ -2503,12 +2527,14 @@ cifs_write_from_iovec(loff_t offset, size_t len, const struct iovec *iov,
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(server, wdata->credits, 0);
kref_put(&wdata->refcount,
cifs_uncached_writedata_release);
if (rc == -EAGAIN) {
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index 8a96342..5e8c22d 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -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,
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index e35ce5b..fecc2de 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 +229,6 @@ 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);
return wsize;
}
@@ -1120,6 +1165,7 @@ 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 +1242,7 @@ 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 +1319,7 @@ 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,
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b0b260d..56bf028 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1906,15 +1906,20 @@ 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 reseted by reconnect */
+ wdata->credits = 0;
goto async_writev_out;
+ }
req->hdr.ProcessId = cpu_to_le32(wdata->cfile->pid);
@@ -1947,9 +1952,20 @@ 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);
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 59c748c..5111e72 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -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 *
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 18cd565..0b5d5fc 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -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;
- rc = wait_for_free_request(server, timeout, optype);
- if (rc)
- return rc;
+ 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(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(server, credits, optype);
return rc;
}
--
1.7.10.4
--
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