Commit a7d5c294 authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: reduce stack use in smb2_compound_op 



Move a lot of structures and arrays off the stack and into a dynamically
allocated structure instead.

Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent baf3f08e

fs/cifs/smb2inode.c

+47 −45
Original line number Diff line number Diff line
@@ -47,6 +47,18 @@ free_set_inf_compound(struct smb_rqst *rqst) 
}





struct cop_vars {

	struct cifs_open_parms oparms;

	struct kvec rsp_iov[3];

	struct smb_rqst rqst[3];

	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];

	struct kvec qi_iov[1];

	struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];

	struct kvec close_iov[1];

	struct smb2_file_rename_info rename_info;

	struct smb2_file_link_info link_info;

};



static int

smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,

		 struct cifs_sb_info *cifs_sb, const char *full_path,
@@ -54,35 +66,33 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		 __u32 create_options, umode_t mode, void *ptr, int command,

		 struct cifsFileInfo *cfile)

{

	struct cop_vars *vars = NULL;

	struct kvec *rsp_iov;

	struct smb_rqst *rqst;

	int rc;

	__le16 *utf16_path = NULL;

	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;

	struct cifs_open_parms oparms;

	struct cifs_fid fid;

	struct cifs_ses *ses = tcon->ses;

	int num_rqst = 0;

	struct smb_rqst rqst[3];

	int resp_buftype[3];

	struct kvec rsp_iov[3];

	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];

	struct kvec qi_iov[1];

	struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];

	struct kvec close_iov[1];

	struct smb2_query_info_rsp *qi_rsp = NULL;

	int flags = 0;

	__u8 delete_pending[8] = {1, 0, 0, 0, 0, 0, 0, 0};

	unsigned int size[2];

	void *data[2];

	struct smb2_file_rename_info rename_info;

	struct smb2_file_link_info link_info;

	int len;



	vars = kzalloc(sizeof(*vars), GFP_ATOMIC);

	if (vars == NULL)

		return -ENOMEM;

	rqst = &vars->rqst[0];

	rsp_iov = &vars->rsp_iov[0];



	if (smb3_encryption_required(tcon))

		flags |= CIFS_TRANSFORM_REQ;



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

	resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;

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



	/* We already have a handle so we can skip the open */

	if (cfile)
@@ -95,19 +105,17 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		goto finished;

	}



	memset(&oparms, 0, sizeof(struct cifs_open_parms));

	oparms.tcon = tcon;

	oparms.desired_access = desired_access;

	oparms.disposition = create_disposition;

	oparms.create_options = cifs_create_options(cifs_sb, create_options);

	oparms.fid = &fid;

	oparms.reconnect = false;

	oparms.mode = mode;



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

	rqst[num_rqst].rq_iov = open_iov;

	vars->oparms.tcon = tcon;

	vars->oparms.desired_access = desired_access;

	vars->oparms.disposition = create_disposition;

	vars->oparms.create_options = cifs_create_options(cifs_sb, create_options);

	vars->oparms.fid = &fid;

	vars->oparms.reconnect = false;

	vars->oparms.mode = mode;



	rqst[num_rqst].rq_iov = &vars->open_iov[0];

	rqst[num_rqst].rq_nvec = SMB2_CREATE_IOV_SIZE;

	rc = SMB2_open_init(tcon, &rqst[num_rqst], &oplock, &oparms,

	rc = SMB2_open_init(tcon, &rqst[num_rqst], &oplock, &vars->oparms,

			    utf16_path);

	kfree(utf16_path);

	if (rc)
@@ -121,8 +129,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
	/* Operation */

	switch (command) {

	case SMB2_OP_QUERY_INFO:

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

		rqst[num_rqst].rq_iov = qi_iov;

		rqst[num_rqst].rq_iov = &vars->qi_iov[0];

		rqst[num_rqst].rq_nvec = 1;



		if (cfile)
@@ -164,8 +171,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		trace_smb3_mkdir_enter(xid, ses->Suid, tcon->tid, full_path);

		break;

	case SMB2_OP_RMDIR:

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

		rqst[num_rqst].rq_iov = si_iov;

		rqst[num_rqst].rq_iov = &vars->si_iov[0];

		rqst[num_rqst].rq_nvec = 1;



		size[0] = 1; /* sizeof __u8 See MS-FSCC section 2.4.11 */
@@ -182,8 +188,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		trace_smb3_rmdir_enter(xid, ses->Suid, tcon->tid, full_path);

		break;

	case SMB2_OP_SET_EOF:

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

		rqst[num_rqst].rq_iov = si_iov;

		rqst[num_rqst].rq_iov = &vars->si_iov[0];

		rqst[num_rqst].rq_nvec = 1;



		size[0] = 8; /* sizeof __le64 */
@@ -200,8 +205,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		trace_smb3_set_eof_enter(xid, ses->Suid, tcon->tid, full_path);

		break;

	case SMB2_OP_SET_INFO:

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

		rqst[num_rqst].rq_iov = si_iov;

		rqst[num_rqst].rq_iov = &vars->si_iov[0];

		rqst[num_rqst].rq_nvec = 1;
@@ -233,18 +237,17 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
						   full_path);

		break;

	case SMB2_OP_RENAME:

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

		rqst[num_rqst].rq_iov = si_iov;

		rqst[num_rqst].rq_iov = &vars->si_iov[0];

		rqst[num_rqst].rq_nvec = 2;



		len = (2 * UniStrnlen((wchar_t *)ptr, PATH_MAX));



		rename_info.ReplaceIfExists = 1;

		rename_info.RootDirectory = 0;

		rename_info.FileNameLength = cpu_to_le32(len);

		vars->rename_info.ReplaceIfExists = 1;

		vars->rename_info.RootDirectory = 0;

		vars->rename_info.FileNameLength = cpu_to_le32(len);



		size[0] = sizeof(struct smb2_file_rename_info);

		data[0] = &rename_info;

		data[0] = &vars->rename_info;



		size[1] = len + 2 /* null */;

		data[1] = (__le16 *)ptr;
@@ -271,18 +274,17 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
		trace_smb3_rename_enter(xid, ses->Suid, tcon->tid, full_path);

		break;

	case SMB2_OP_HARDLINK:

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

		rqst[num_rqst].rq_iov = si_iov;

		rqst[num_rqst].rq_iov = &vars->si_iov[0];

		rqst[num_rqst].rq_nvec = 2;



		len = (2 * UniStrnlen((wchar_t *)ptr, PATH_MAX));



		link_info.ReplaceIfExists = 0;

		link_info.RootDirectory = 0;

		link_info.FileNameLength = cpu_to_le32(len);

		vars->link_info.ReplaceIfExists = 0;

		vars->link_info.RootDirectory = 0;

		vars->link_info.FileNameLength = cpu_to_le32(len);



		size[0] = sizeof(struct smb2_file_link_info);

		data[0] = &link_info;

		data[0] = &vars->link_info;



		size[1] = len + 2 /* null */;

		data[1] = (__le16 *)ptr;
@@ -308,8 +310,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
	if (cfile)

		goto after_close;

	/* Close */

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

	rqst[num_rqst].rq_iov = close_iov;

	rqst[num_rqst].rq_iov = &vars->close_iov[0];

	rqst[num_rqst].rq_nvec = 1;

	rc = SMB2_close_init(tcon, &rqst[num_rqst], COMPOUND_FID,

			     COMPOUND_FID, false);
@@ -420,6 +421,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon, 
	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);

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

	free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);

	kfree(vars);

	return rc;

}

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