Commit 8e670f77 authored by Rohith Surabattula's avatar Rohith Surabattula Committed by Steve French
Browse files

Handle STATUS_IO_TIMEOUT gracefully 



Currently STATUS_IO_TIMEOUT is not treated as retriable error.
It is currently mapped to ETIMEDOUT and returned to userspace
for most system calls. STATUS_IO_TIMEOUT is returned by server
in case of unavailability or throttling errors.

This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it
can be retried. Also, added a check to drop the connection to
not overload the server in case of ongoing unavailability.

Signed-off-by: default avatarRohith Surabattula <rohiths@microsoft.com>
Reviewed-by: default avatarAurelien Aptel <aaptel@suse.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent d1542cf6

fs/cifs/cifsglob.h

+2 −0
Original line number Diff line number Diff line
@@ -510,6 +510,8 @@ struct smb_version_operations { 
		      struct fiemap_extent_info *, u64, u64);

	/* version specific llseek implementation */

	loff_t (*llseek)(struct file *, struct cifs_tcon *, loff_t, int);

	/* Check for STATUS_IO_TIMEOUT */

	bool (*is_status_io_timeout)(char *buf);

};



struct smb_version_values {

fs/cifs/connect.c

+14 −1
Original line number Diff line number Diff line
@@ -69,6 +69,9 @@ extern bool disable_legacy_dialects; 
#define TLINK_ERROR_EXPIRE	(1 * HZ)

#define TLINK_IDLE_EXPIRE	(600 * HZ)



/* Drop the connection to not overload the server */

#define NUM_STATUS_IO_TIMEOUT   5



enum {

	/* Mount options that take no arguments */

	Opt_user_xattr, Opt_nouser_xattr,
@@ -1117,7 +1120,7 @@ cifs_demultiplex_thread(void *p) 
	struct task_struct *task_to_wake = NULL;

	struct mid_q_entry *mids[MAX_COMPOUND];

	char *bufs[MAX_COMPOUND];

	unsigned int noreclaim_flag;

	unsigned int noreclaim_flag, num_io_timeout = 0;



	noreclaim_flag = memalloc_noreclaim_save();

	cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
@@ -1213,6 +1216,16 @@ next_pdu: 
			continue;

		}



		if (server->ops->is_status_io_timeout &&

		    server->ops->is_status_io_timeout(buf)) {

			num_io_timeout++;

			if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {

				cifs_reconnect(server);

				num_io_timeout = 0;

				continue;

			}

		}



		server->lstrp = jiffies;



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

fs/cifs/smb2maperror.c

+1 −1
Original line number Diff line number Diff line
@@ -488,7 +488,7 @@ static const struct status_to_posix_error smb2_error_map_table[] = { 
	{STATUS_PIPE_CONNECTED, -EIO, "STATUS_PIPE_CONNECTED"},

	{STATUS_PIPE_LISTENING, -EIO, "STATUS_PIPE_LISTENING"},

	{STATUS_INVALID_READ_MODE, -EIO, "STATUS_INVALID_READ_MODE"},

	{STATUS_IO_TIMEOUT, -ETIMEDOUT, "STATUS_IO_TIMEOUT"},

	{STATUS_IO_TIMEOUT, -EAGAIN, "STATUS_IO_TIMEOUT"},

	{STATUS_FILE_FORCED_CLOSED, -EIO, "STATUS_FILE_FORCED_CLOSED"},

	{STATUS_PROFILING_NOT_STARTED, -EIO, "STATUS_PROFILING_NOT_STARTED"},

	{STATUS_PROFILING_NOT_STOPPED, -EIO, "STATUS_PROFILING_NOT_STOPPED"},

fs/cifs/smb2ops.c

+15 −0
Original line number Diff line number Diff line
@@ -2354,6 +2354,17 @@ smb2_is_session_expired(char *buf) 
	return true;

}



static bool

smb2_is_status_io_timeout(char *buf)

{

	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;



	if (shdr->Status == STATUS_IO_TIMEOUT)

		return true;

	else

		return false;

}



static int

smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,

		     struct cifsInodeInfo *cinode)
@@ -4817,6 +4828,7 @@ struct smb_version_operations smb20_operations = { 
	.make_node = smb2_make_node,

	.fiemap = smb3_fiemap,

	.llseek = smb3_llseek,

	.is_status_io_timeout = smb2_is_status_io_timeout,

};



struct smb_version_operations smb21_operations = {
@@ -4917,6 +4929,7 @@ struct smb_version_operations smb21_operations = { 
	.make_node = smb2_make_node,

	.fiemap = smb3_fiemap,

	.llseek = smb3_llseek,

	.is_status_io_timeout = smb2_is_status_io_timeout,

};



struct smb_version_operations smb30_operations = {
@@ -5027,6 +5040,7 @@ struct smb_version_operations smb30_operations = { 
	.make_node = smb2_make_node,

	.fiemap = smb3_fiemap,

	.llseek = smb3_llseek,

	.is_status_io_timeout = smb2_is_status_io_timeout,

};



struct smb_version_operations smb311_operations = {
@@ -5138,6 +5152,7 @@ struct smb_version_operations smb311_operations = { 
	.make_node = smb2_make_node,

	.fiemap = smb3_fiemap,

	.llseek = smb3_llseek,

	.is_status_io_timeout = smb2_is_status_io_timeout,

};



struct smb_version_values smb20_values = {

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