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Commit 335b7b62 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Respect reconnect in MTU credits calculations 



Every time after a session reconnect we don't need to account for
credits obtained in previous sessions. Introduce new struct cifs_credits
which contains both credits value and reconnect instance of the
time those credits were taken. Modify a routine that add credits
back to handle the reconnect instance by assuming zero credits
if the reconnect happened after the credits were obtained and
before we decided to add them back due to some errors during sending.

This patch fixes the MTU credits cases. The subsequent patch
will handle non-MTU ones.

Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 5b964852

fs/cifs/cifsglob.h

+19 −10
Original line number Diff line number Diff line
@@ -216,6 +216,7 @@ struct cifs_io_parms; 
struct cifs_search_info;

struct cifsInodeInfo;

struct cifs_open_parms;

struct cifs_credits;



struct smb_version_operations {

	int (*send_cancel)(struct TCP_Server_Info *, struct smb_rqst *,
@@ -230,8 +231,9 @@ struct smb_version_operations { 
	/* check response: verify signature, map error */

	int (*check_receive)(struct mid_q_entry *, struct TCP_Server_Info *,

			     bool);

	void (*add_credits)(struct TCP_Server_Info *, const unsigned int,

			    const int);

	void (*add_credits)(struct TCP_Server_Info *server,

			    const struct cifs_credits *credits,

			    const int optype);

	void (*set_credits)(struct TCP_Server_Info *, const int);

	int * (*get_credits_field)(struct TCP_Server_Info *, const int);

	unsigned int (*get_credits)(struct mid_q_entry *);
@@ -454,7 +456,7 @@ struct smb_version_operations { 
	unsigned int (*wp_retry_size)(struct inode *);

	/* get mtu credits */

	int (*wait_mtu_credits)(struct TCP_Server_Info *, unsigned int,

				unsigned int *, unsigned int *);

				unsigned int *, struct cifs_credits *);

	/* check if we need to issue closedir */

	bool (*dir_needs_close)(struct cifsFileInfo *);

	long (*fallocate)(struct file *, struct cifs_tcon *, int, loff_t,
@@ -713,6 +715,11 @@ struct TCP_Server_Info { 
	int nr_targets;

};



struct cifs_credits {

	unsigned int value;

	unsigned int instance;

};



static inline unsigned int

in_flight(struct TCP_Server_Info *server)

{
@@ -737,15 +744,17 @@ static inline void 
add_credits(struct TCP_Server_Info *server, const unsigned int add,

	    const int optype)

{

	server->ops->add_credits(server, add, optype);

	struct cifs_credits credits = { .value = add, .instance = 0 };



	server->ops->add_credits(server, &credits, optype);

}



static inline void

add_credits_and_wake_if(struct TCP_Server_Info *server, const unsigned int add,

			const int optype)

add_credits_and_wake_if(struct TCP_Server_Info *server,

			const struct cifs_credits *credits, const int optype)

{

	if (add) {

		server->ops->add_credits(server, add, optype);

	if (credits->value) {

		server->ops->add_credits(server, credits, optype);

		wake_up(&server->request_q);

	}

}
@@ -1253,7 +1262,7 @@ struct cifs_readdata { 
	unsigned int			pagesz;

	unsigned int			page_offset;

	unsigned int			tailsz;

	unsigned int			credits;

	struct cifs_credits		credits;

	unsigned int			nr_pages;

	struct page			**pages;

};
@@ -1279,7 +1288,7 @@ struct cifs_writedata { 
	unsigned int			pagesz;

	unsigned int			page_offset;

	unsigned int			tailsz;

	unsigned int			credits;

	struct cifs_credits		credits;

	unsigned int			nr_pages;

	struct page			**pages;

};

fs/cifs/cifsproto.h

+1 −1
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ 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);

				 struct cifs_credits *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,

fs/cifs/connect.c

+1 −2
Original line number Diff line number Diff line
@@ -593,6 +593,7 @@ cifs_reconnect(struct TCP_Server_Info *server) 
			msleep(3000);

		} else {

			atomic_inc(&tcpSesReconnectCount);

			set_credits(server, 1);

			spin_lock(&GlobalMid_Lock);

			if (server->tcpStatus != CifsExiting)

				server->tcpStatus = CifsNeedNegotiate;
@@ -4951,8 +4952,6 @@ cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses) 
	if (!server->ops->need_neg(server))

		return 0;



	set_credits(server, 1);



	rc = server->ops->negotiate(xid, ses);

	if (rc == 0) {

		spin_lock(&GlobalMid_Lock);

fs/cifs/file.c

+38 −24
Original line number Diff line number Diff line
@@ -2143,11 +2143,13 @@ static int cifs_writepages(struct address_space *mapping, 
	server = cifs_sb_master_tcon(cifs_sb)->ses->server;

retry:

	while (!done && index <= end) {

		unsigned int i, nr_pages, found_pages, wsize, credits;

		unsigned int i, nr_pages, found_pages, wsize;

		pgoff_t next = 0, tofind, saved_index = index;

		struct cifs_credits credits_on_stack;

		struct cifs_credits *credits = &credits_on_stack;



		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,

						   &wsize, &credits);

						   &wsize, credits);

		if (rc != 0) {

			done = true;

			break;
@@ -2180,13 +2182,13 @@ static int cifs_writepages(struct address_space *mapping, 
			continue;

		}



		wdata->credits = credits;

		wdata->credits = credits_on_stack;



		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);

			add_credits_and_wake_if(server, &wdata->credits, 0);

			for (i = 0; i < nr_pages; ++i) {

				if (is_retryable_error(rc))

					redirty_page_for_writepage(wbc,
@@ -2567,7 +2569,8 @@ static int 
cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,

	struct cifs_aio_ctx *ctx)

{

	unsigned int wsize, credits;

	unsigned int wsize;

	struct cifs_credits credits;

	int rc;

	struct TCP_Server_Info *server =

		tlink_tcon(wdata->cfile->tlink)->ses->server;
@@ -2577,18 +2580,19 @@ cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list, 
	 * Note: we are attempting to resend the whole wdata not in segments

	 */

	do {

		rc = server->ops->wait_mtu_credits(

			server, wdata->bytes, &wsize, &credits);

		rc = server->ops->wait_mtu_credits(server, wdata->bytes, &wsize,

						   &credits);



		if (rc)

			goto out;



		if (wsize < wdata->bytes) {

			add_credits_and_wake_if(server, credits, 0);

			add_credits_and_wake_if(server, &credits, 0);

			msleep(1000);

		}

	} while (wsize < wdata->bytes);



	wdata->credits = credits;

	rc = -EAGAIN;

	while (rc == -EAGAIN) {

		rc = 0;
@@ -2604,7 +2608,7 @@ cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list, 
		return 0;

	}



	add_credits_and_wake_if(server, wdata->credits, 0);

	add_credits_and_wake_if(server, &wdata->credits, 0);

out:

	kref_put(&wdata->refcount, cifs_uncached_writedata_release);
@@ -2627,6 +2631,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
	struct TCP_Server_Info *server;

	struct page **pagevec;

	size_t start;

	unsigned int xid;



	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)

		pid = open_file->pid;
@@ -2634,12 +2639,15 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
		pid = current->tgid;



	server = tlink_tcon(open_file->tlink)->ses->server;

	xid = get_xid();



	do {

		unsigned int wsize, credits;

		unsigned int wsize;

		struct cifs_credits credits_on_stack;

		struct cifs_credits *credits = &credits_on_stack;



		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,

						   &wsize, &credits);

						   &wsize, credits);

		if (rc)

			break;
@@ -2731,7 +2739,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
		wdata->pid = pid;

		wdata->bytes = cur_len;

		wdata->pagesz = PAGE_SIZE;

		wdata->credits = credits;

		wdata->credits = credits_on_stack;

		wdata->ctx = ctx;

		kref_get(&ctx->refcount);
@@ -2740,7 +2748,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
			rc = server->ops->async_writev(wdata,

					cifs_uncached_writedata_release);

		if (rc) {

			add_credits_and_wake_if(server, wdata->credits, 0);

			add_credits_and_wake_if(server, &wdata->credits, 0);

			kref_put(&wdata->refcount,

				 cifs_uncached_writedata_release);

			if (rc == -EAGAIN) {
@@ -2756,6 +2764,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, 
		len -= cur_len;

	} while (len > 0);



	free_xid(xid);

	return rc;

}
@@ -3260,7 +3269,8 @@ static int cifs_resend_rdata(struct cifs_readdata *rdata, 
			struct list_head *rdata_list,

			struct cifs_aio_ctx *ctx)

{

	unsigned int rsize, credits;

	unsigned int rsize;

	struct cifs_credits credits;

	int rc;

	struct TCP_Server_Info *server =

		tlink_tcon(rdata->cfile->tlink)->ses->server;
@@ -3277,11 +3287,12 @@ static int cifs_resend_rdata(struct cifs_readdata *rdata, 
			goto out;



		if (rsize < rdata->bytes) {

			add_credits_and_wake_if(server, credits, 0);

			add_credits_and_wake_if(server, &credits, 0);

			msleep(1000);

		}

	} while (rsize < rdata->bytes);



	rdata->credits = credits;

	rc = -EAGAIN;

	while (rc == -EAGAIN) {

		rc = 0;
@@ -3297,7 +3308,7 @@ static int cifs_resend_rdata(struct cifs_readdata *rdata, 
		return 0;

	}



	add_credits_and_wake_if(server, rdata->credits, 0);

	add_credits_and_wake_if(server, &rdata->credits, 0);

out:

	kref_put(&rdata->refcount,

		cifs_uncached_readdata_release);
@@ -3311,7 +3322,9 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 
		     struct cifs_aio_ctx *ctx)

{

	struct cifs_readdata *rdata;

	unsigned int npages, rsize, credits;

	unsigned int npages, rsize;

	struct cifs_credits credits_on_stack;

	struct cifs_credits *credits = &credits_on_stack;

	size_t cur_len;

	int rc;

	pid_t pid;
@@ -3332,7 +3345,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 


	do {

		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,

						   &rsize, &credits);

						   &rsize, credits);

		if (rc)

			break;
@@ -3406,7 +3419,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 
		rdata->pagesz = PAGE_SIZE;

		rdata->read_into_pages = cifs_uncached_read_into_pages;

		rdata->copy_into_pages = cifs_uncached_copy_into_pages;

		rdata->credits = credits;

		rdata->credits = credits_on_stack;

		rdata->ctx = ctx;

		kref_get(&ctx->refcount);
@@ -3414,7 +3427,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, 
		    !(rc = cifs_reopen_file(rdata->cfile, true)))

			rc = server->ops->async_readv(rdata);

		if (rc) {

			add_credits_and_wake_if(server, rdata->credits, 0);

			add_credits_and_wake_if(server, &rdata->credits, 0);

			kref_put(&rdata->refcount,

				cifs_uncached_readdata_release);

			if (rc == -EAGAIN) {
@@ -4093,10 +4106,11 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, 
		loff_t offset;

		struct page *page, *tpage;

		struct cifs_readdata *rdata;

		unsigned credits;

		struct cifs_credits credits_on_stack;

		struct cifs_credits *credits = &credits_on_stack;



		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,

						   &rsize, &credits);

						   &rsize, credits);

		if (rc)

			break;
@@ -4142,7 +4156,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, 
		rdata->tailsz = PAGE_SIZE;

		rdata->read_into_pages = cifs_readpages_read_into_pages;

		rdata->copy_into_pages = cifs_readpages_copy_into_pages;

		rdata->credits = credits;

		rdata->credits = credits_on_stack;



		list_for_each_entry_safe(page, tpage, &tmplist, lru) {

			list_del(&page->lru);
@@ -4153,7 +4167,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, 
		    !(rc = cifs_reopen_file(rdata->cfile, true)))

			rc = server->ops->async_readv(rdata);

		if (rc) {

			add_credits_and_wake_if(server, rdata->credits, 0);

			add_credits_and_wake_if(server, &rdata->credits, 0);

			for (i = 0; i < rdata->nr_pages; i++) {

				page = rdata->pages[i];

				lru_cache_add_file(page);

fs/cifs/smb1ops.c

+3 −3
Original line number Diff line number Diff line
@@ -117,11 +117,11 @@ cifs_find_mid(struct TCP_Server_Info *server, char *buffer) 
}



static void

cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add,

		 const int optype)

cifs_add_credits(struct TCP_Server_Info *server,

		 const struct cifs_credits *credits, const int optype)

{

	spin_lock(&server->req_lock);

	server->credits += add;

	server->credits += credits->value;

	server->in_flight--;

	spin_unlock(&server->req_lock);

	wake_up(&server->request_q);