Commit b0f6df73 authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: cache FILE_ALL_INFO for the shared root handle 



When we open the shared root handle also ask for FILE_ALL_INFORMATION since
we can do this at zero cost as part of a compound.
Cache this information as long as the lease is held and return and serve any
future requests from cache.

This allows us to serve "stat /<mountpoint>" directly from cache and avoid
a network roundtrip.  Since clients often want to do this quite a lot
this improve performance slightly.

As an example: xfstest generic/533 performs 43 stat operations on the root
of the share while it is run. Which are eliminated with this patch.

Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
parent ab7b10cf

fs/cifs/cifsglob.h

+3 −0
Original line number Diff line number Diff line
@@ -962,11 +962,14 @@ cap_unix(struct cifs_ses *ses) 


struct cached_fid {

	bool is_valid:1;	/* Do we have a useable root fid */

	bool file_all_info_is_valid:1;



	struct kref refcount;

	struct cifs_fid *fid;

	struct mutex fid_mutex;

	struct cifs_tcon *tcon;

	struct work_struct lease_break;

	struct smb2_file_all_info file_all_info;

};



/*

fs/cifs/smb2inode.c

+10 −5
Original line number Diff line number Diff line
@@ -309,12 +309,17 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon, 
		rc = open_shroot(xid, tcon, &fid);

		if (rc)

			goto out;



		if (tcon->crfid.file_all_info_is_valid) {

			move_smb2_info_to_cifs(data,

					       &tcon->crfid.file_all_info);

		} else {

			rc = SMB2_query_info(xid, tcon, fid.persistent_fid,

					     fid.volatile_fid, smb2_data);

		close_shroot(&tcon->crfid);

		if (rc)

			goto out;

			if (!rc)

				move_smb2_info_to_cifs(data, smb2_data);

		}

		close_shroot(&tcon->crfid);

		goto out;

	}

fs/cifs/smb2ops.c

+95 −18
Original line number Diff line number Diff line
@@ -619,6 +619,7 @@ smb2_close_cached_fid(struct kref *ref) 
		SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,

			   cfid->fid->volatile_fid);

		cfid->is_valid = false;

		cfid->file_all_info_is_valid = false;

	}

}
@@ -643,9 +644,18 @@ smb2_cached_lease_break(struct work_struct *work) 
 */

int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)

{

	struct cifs_open_parms oparams;

	int rc;

	__le16 srch_path = 0; /* Null - since an open of top of share */

	struct cifs_ses *ses = tcon->ses;

	struct TCP_Server_Info *server = ses->server;

	struct cifs_open_parms oparms;

	struct smb2_create_rsp *o_rsp = NULL;

	struct smb2_query_info_rsp *qi_rsp = NULL;

	int resp_buftype[2];

	struct smb_rqst rqst[2];

	struct kvec rsp_iov[2];

	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];

	struct kvec qi_iov[1];

	int rc, flags = 0;

	__le16 utf16_path = 0; /* Null - since an open of top of share */

	u8 oplock = SMB2_OPLOCK_LEVEL_II;



	mutex_lock(&tcon->crfid.fid_mutex);
@@ -657,22 +667,89 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) 
		return 0;

	}



	oparams.tcon = tcon;

	oparams.create_options = 0;

	oparams.desired_access = FILE_READ_ATTRIBUTES;

	oparams.disposition = FILE_OPEN;

	oparams.fid = pfid;

	oparams.reconnect = false;

	if (smb3_encryption_required(tcon))

		flags |= CIFS_TRANSFORM_REQ;



	memset(rqst, 0, sizeof(rqst));

	resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;

	memset(rsp_iov, 0, sizeof(rsp_iov));



	/* Open */

	memset(&open_iov, 0, sizeof(open_iov));

	rqst[0].rq_iov = open_iov;

	rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;



	oparms.tcon = tcon;

	oparms.create_options = 0;

	oparms.desired_access = FILE_READ_ATTRIBUTES;

	oparms.disposition = FILE_OPEN;

	oparms.fid = pfid;

	oparms.reconnect = false;



	rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, &utf16_path);

	if (rc)

		goto oshr_exit;

	smb2_set_next_command(tcon, &rqst[0]);



	memset(&qi_iov, 0, sizeof(qi_iov));

	rqst[1].rq_iov = qi_iov;

	rqst[1].rq_nvec = 1;



	rc = SMB2_query_info_init(tcon, &rqst[1], COMPOUND_FID,

				  COMPOUND_FID, FILE_ALL_INFORMATION,

				  SMB2_O_INFO_FILE, 0,

				  sizeof(struct smb2_file_all_info) +

				  PATH_MAX * 2, 0, NULL);

	if (rc)

		goto oshr_exit;



	smb2_set_related(&rqst[1]);



	rc = compound_send_recv(xid, ses, flags, 2, rqst,

				resp_buftype, rsp_iov);

	if (rc)

		goto oshr_exit;



	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;

	oparms.fid->persistent_fid = o_rsp->PersistentFileId;

	oparms.fid->volatile_fid = o_rsp->VolatileFileId;

#ifdef CONFIG_CIFS_DEBUG2

	oparms.fid->mid = le64_to_cpu(o_rsp->sync_hdr.MessageId);

#endif /* CIFS_DEBUG2 */



	if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE)

		oplock = smb2_parse_lease_state(server, o_rsp,

						&oparms.fid->epoch,

						oparms.fid->lease_key);

	else

		goto oshr_exit;





	rc = SMB2_open(xid, &oparams, &srch_path, &oplock, NULL, NULL, NULL);

	if (rc == 0) {

	memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));

	tcon->crfid.tcon = tcon;

	tcon->crfid.is_valid = true;

	kref_init(&tcon->crfid.refcount);

	kref_get(&tcon->crfid.refcount);

	}





	qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;

	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))

		goto oshr_exit;

	rc = smb2_validate_and_copy_iov(

				le16_to_cpu(qi_rsp->OutputBufferOffset),

				sizeof(struct smb2_file_all_info),

				&rsp_iov[1], sizeof(struct smb2_file_all_info),

				(char *)&tcon->crfid.file_all_info);

	if (rc)

		goto oshr_exit;

	tcon->crfid.file_all_info_is_valid = 1;



 oshr_exit:

	mutex_unlock(&tcon->crfid.fid_mutex);

	SMB2_open_free(&rqst[0]);

	SMB2_query_info_free(&rqst[1]);

	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);

	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);

	return rc;

}

fs/cifs/smb2pdu.c

+7 −5
Original line number Diff line number Diff line
@@ -1797,8 +1797,9 @@ create_reconnect_durable_buf(struct cifs_fid *fid) 
	return buf;

}



static __u8

parse_lease_state(struct TCP_Server_Info *server, struct smb2_create_rsp *rsp,

__u8

smb2_parse_lease_state(struct TCP_Server_Info *server,

		       struct smb2_create_rsp *rsp,

		       unsigned int *epoch, char *lease_key)

{

	char *data_offset;
@@ -2456,7 +2457,8 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path, 
	}



	if (rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE)

		*oplock = parse_lease_state(server, rsp, &oparms->fid->epoch,

		*oplock = smb2_parse_lease_state(server, rsp,

						 &oparms->fid->epoch,

						 oparms->fid->lease_key);

	else

		*oplock = rsp->OplockLevel;

fs/cifs/smb2proto.h

+3 −0
Original line number Diff line number Diff line
@@ -223,6 +223,9 @@ extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *); 


extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *,

					enum securityEnum);

extern __u8 smb2_parse_lease_state(struct TCP_Server_Info *server,

				   struct smb2_create_rsp *rsp,

				   unsigned int *epoch, char *lease_key);

extern int smb3_encryption_required(const struct cifs_tcon *tcon);

extern int smb2_validate_iov(unsigned int offset, unsigned int buffer_length,

			     struct kvec *iov, unsigned int min_buf_size);

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