Currently we adjust MTU credits before sending an IO request
and after reopening a file. This approach doesn't allow the
reopen routine to use existing credits that are not needed
for IO. Reorder credit adjustment and reopening a file to
use credits available to the client more efficiently. Also
unwrap complex if statement into few pieces to improve
readability.
Signed-off-by: Pavel Shilovsky <pshilov@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/cifsglob.h | 12 ++++++++++++
fs/cifs/file.c | 53 +++++++++++++++++++++++++++++++++++++++--------------
fs/cifs/smb2ops.c | 35 +++++++++++++++++++++++++++++++++++
fs/cifs/smb2pdu.c | 36 ++++++++----------------------------
4 files changed, 94 insertions(+), 42 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 545b91d..5bf463c 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -455,6 +455,10 @@ struct smb_version_operations {
/* get mtu credits */
int (*wait_mtu_credits)(struct TCP_Server_Info *, unsigned int,
unsigned int *, struct cifs_credits *);
+ /* adjust previously taken mtu credits to request size */
+ int (*adjust_credits)(struct TCP_Server_Info *server,
+ struct cifs_credits *credits,
+ const unsigned int payload_size);
/* check if we need to issue closedir */
bool (*dir_needs_close)(struct cifsFileInfo *);
long (*fallocate)(struct file *, struct cifs_tcon *, int, loff_t,
@@ -760,6 +764,14 @@ set_credits(struct TCP_Server_Info *server, const int val)
server->ops->set_credits(server, val);
}
+static inline int
+adjust_credits(struct TCP_Server_Info *server, struct cifs_credits *credits,
+ const unsigned int payload_size)
+{
+ return server->ops->adjust_credits ?
+ server->ops->adjust_credits(server, credits, payload_size) : 0;
+}
+
static inline __le64
get_next_mid64(struct TCP_Server_Info *server)
{
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2adcf42..e793b55 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2076,11 +2076,11 @@ wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
}
static int
-wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
- struct address_space *mapping, struct writeback_control *wbc)
+wdata_send_pages(struct TCP_Server_Info *server, struct cifs_writedata *wdata,
+ unsigned int nr_pages, struct address_space *mapping,
+ struct writeback_control *wbc)
{
int rc = 0;
- struct TCP_Server_Info *server;
unsigned int i;
wdata->sync_mode = wbc->sync_mode;
@@ -2092,6 +2092,10 @@ wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
(loff_t)PAGE_SIZE);
wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
+ rc = adjust_credits(server, &wdata->credits, wdata->bytes);
+ if (rc)
+ goto send_pages_out;
+
if (wdata->cfile != NULL)
cifsFileInfo_put(wdata->cfile);
wdata->cfile = find_writable_file(CIFS_I(mapping->host), false);
@@ -2100,10 +2104,10 @@ wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
rc = -EBADF;
} else {
wdata->pid = wdata->cfile->pid;
- server = tlink_tcon(wdata->cfile->tlink)->ses->server;
rc = server->ops->async_writev(wdata, cifs_writedata_release);
}
+send_pages_out:
for (i = 0; i < nr_pages; ++i)
unlock_page(wdata->pages[i]);
@@ -2184,7 +2188,7 @@ static int cifs_writepages(struct address_space *mapping,
wdata->credits = credits_on_stack;
- rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
+ rc = wdata_send_pages(server, wdata, nr_pages, mapping, wbc);
/* send failure -- clean up the mess */
if (rc != 0) {
@@ -2743,10 +2747,17 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
wdata->ctx = ctx;
kref_get(&ctx->refcount);
- if (!wdata->cfile->invalidHandle ||
- !(rc = cifs_reopen_file(wdata->cfile, false)))
- rc = server->ops->async_writev(wdata,
+ rc = adjust_credits(server, &wdata->credits, wdata->bytes);
+
+ if (!rc) {
+ if (wdata->cfile->invalidHandle)
+ rc = cifs_reopen_file(wdata->cfile, false);
+
+ if (!rc)
+ 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,
@@ -3423,9 +3434,16 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
rdata->ctx = ctx;
kref_get(&ctx->refcount);
- if (!rdata->cfile->invalidHandle ||
- !(rc = cifs_reopen_file(rdata->cfile, true)))
- rc = server->ops->async_readv(rdata);
+ rc = adjust_credits(server, &rdata->credits, rdata->bytes);
+
+ if (!rc) {
+ if (rdata->cfile->invalidHandle)
+ rc = cifs_reopen_file(rdata->cfile, true);
+
+ if (!rc)
+ rc = server->ops->async_readv(rdata);
+ }
+
if (rc) {
add_credits_and_wake_if(server, &rdata->credits, 0);
kref_put(&rdata->refcount,
@@ -4165,9 +4183,16 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
rdata->pages[rdata->nr_pages++] = page;
}
- if (!rdata->cfile->invalidHandle ||
- !(rc = cifs_reopen_file(rdata->cfile, true)))
- rc = server->ops->async_readv(rdata);
+ rc = adjust_credits(server, &rdata->credits, rdata->bytes);
+
+ if (!rc) {
+ if (rdata->cfile->invalidHandle)
+ rc = cifs_reopen_file(rdata->cfile, true);
+
+ if (!rc)
+ rc = server->ops->async_readv(rdata);
+ }
+
if (rc) {
add_credits_and_wake_if(server, &rdata->credits, 0);
for (i = 0; i < rdata->nr_pages; i++) {
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 354a7bc..1995bbe 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -222,6 +222,38 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
return rc;
}
+static int
+smb2_adjust_credits(struct TCP_Server_Info *server,
+ struct cifs_credits *credits,
+ const unsigned int payload_size)
+{
+ int new_val = DIV_ROUND_UP(payload_size, SMB2_MAX_BUFFER_SIZE);
+
+ if (!credits->value || credits->value == new_val)
+ return 0;
+
+ if (credits->value < new_val) {
+ WARN_ONCE(1, "request has less credits (%d) than required (%d)",
+ credits->value, new_val);
+ return -ENOTSUPP;
+ }
+
+ spin_lock(&server->req_lock);
+
+ if (server->reconnect_instance != credits->instance) {
+ spin_unlock(&server->req_lock);
+ cifs_dbg(VFS, "trying to return %d credits to old session\n",
+ credits->value - new_val);
+ return -EAGAIN;
+ }
+
+ server->credits += credits->value - new_val;
+ spin_unlock(&server->req_lock);
+ wake_up(&server->request_q);
+ credits->value = new_val;
+ return 0;
+}
+
static __u64
smb2_get_next_mid(struct TCP_Server_Info *server)
{
@@ -3649,6 +3681,7 @@ struct smb_version_operations smb21_operations = {
.get_credits_field = smb2_get_credits_field,
.get_credits = smb2_get_credits,
.wait_mtu_credits = smb2_wait_mtu_credits,
+ .adjust_credits = smb2_adjust_credits,
.get_next_mid = smb2_get_next_mid,
.read_data_offset = smb2_read_data_offset,
.read_data_length = smb2_read_data_length,
@@ -3745,6 +3778,7 @@ struct smb_version_operations smb30_operations = {
.get_credits_field = smb2_get_credits_field,
.get_credits = smb2_get_credits,
.wait_mtu_credits = smb2_wait_mtu_credits,
+ .adjust_credits = smb2_adjust_credits,
.get_next_mid = smb2_get_next_mid,
.read_data_offset = smb2_read_data_offset,
.read_data_length = smb2_read_data_length,
@@ -3850,6 +3884,7 @@ struct smb_version_operations smb311_operations = {
.get_credits_field = smb2_get_credits_field,
.get_credits = smb2_get_credits,
.wait_mtu_credits = smb2_wait_mtu_credits,
+ .adjust_credits = smb2_adjust_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 8f92c22..ae558a4 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3313,21 +3313,11 @@ smb2_async_readv(struct cifs_readdata *rdata)
SMB2_MAX_BUFFER_SIZE));
shdr->CreditRequest =
cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
- spin_lock(&server->req_lock);
- if (server->reconnect_instance == rdata->credits.instance)
- server->credits += rdata->credits.value -
- le16_to_cpu(shdr->CreditCharge);
- else {
- spin_unlock(&server->req_lock);
- cifs_dbg(VFS, "trying to return %u credits to old session\n",
- rdata->credits.value
- - le16_to_cpu(shdr->CreditCharge));
- rc = -EAGAIN;
+
+ rc = adjust_credits(server, &rdata->credits, rdata->bytes);
+ if (rc)
goto async_readv_out;
- }
- spin_unlock(&server->req_lock);
- wake_up(&server->request_q);
- rdata->credits.value = le16_to_cpu(shdr->CreditCharge);
+
flags |= CIFS_HAS_CREDITS;
}
@@ -3617,21 +3607,11 @@ smb2_async_writev(struct cifs_writedata *wdata,
SMB2_MAX_BUFFER_SIZE));
shdr->CreditRequest =
cpu_to_le16(le16_to_cpu(shdr->CreditCharge) + 1);
- spin_lock(&server->req_lock);
- if (server->reconnect_instance == wdata->credits.instance)
- server->credits += wdata->credits.value -
- le16_to_cpu(shdr->CreditCharge);
- else {
- spin_unlock(&server->req_lock);
- cifs_dbg(VFS, "trying to return %d credits to old session\n",
- wdata->credits.value
- - le16_to_cpu(shdr->CreditCharge));
- rc = -EAGAIN;
+
+ rc = adjust_credits(server, &wdata->credits, wdata->bytes);
+ if (rc)
goto async_writev_out;
- }
- spin_unlock(&server->req_lock);
- wake_up(&server->request_q);
- wdata->credits.value = le16_to_cpu(shdr->CreditCharge);
+
flags |= CIFS_HAS_CREDITS;
}
--
2.7.4
