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Commit 9a1c67e8 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Adjust MTU credits before reopening a file 



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: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 97ea4998

fs/cifs/cifsglob.h

+12 −0
Original line number Diff line number Diff line
@@ -457,6 +457,10 @@ 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,
@@ -763,6 +767,14 @@ 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)

{

fs/cifs/file.c

+39 −14
Original line number Diff line number Diff line
@@ -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 = 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 = 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,
@@ -4163,9 +4181,16 @@ 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 = 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++) {

fs/cifs/smb2ops.c

+35 −0
Original line number Diff line number Diff line
@@ -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)

{
@@ -3678,6 +3710,7 @@ 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,

	.revert_current_mid = smb2_revert_current_mid,

	.read_data_offset = smb2_read_data_offset,
@@ -3775,6 +3808,7 @@ 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,

	.revert_current_mid = smb2_revert_current_mid,

	.read_data_offset = smb2_read_data_offset,
@@ -3881,6 +3915,7 @@ 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,

	.revert_current_mid = smb2_revert_current_mid,

	.read_data_offset = smb2_read_data_offset,

fs/cifs/smb2pdu.c

+8 −28
Original line number Diff line number Diff line
@@ -3322,21 +3322,11 @@ 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;

	}
@@ -3626,21 +3616,11 @@ 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;

	}