smb: client: reduce stack usage in smb2_query_info_compound()

Clang warns about exceeded stack frame size

  fs/smb/client/smb2ops.c:2521:1: warning: stack frame size (1336)
  exceeds limit (1024) in 'smb2_query_info_compound'
  [-Wframe-larger-than]

Fix this by allocating a structure that will hold most of the large
variables.

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index d31ea7e7fd8413b0842a06ed03c85dc1bf2eb9e8..015d13d9054dd79fa62a24b87614ea69f1d29960 100644 (file)
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -2513,15 +2513,13 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
                         struct kvec *rsp, int *buftype,
                         struct cifs_sb_info *cifs_sb)
 {
+       struct smb2_compound_vars *vars;
        struct cifs_ses *ses = tcon->ses;
        struct TCP_Server_Info *server = cifs_pick_channel(ses);
        int flags = CIFS_CP_CREATE_CLOSE_OP;
-       struct smb_rqst rqst[3];
+       struct smb_rqst *rqst;
        int resp_buftype[3];
-       struct kvec rsp_iov[3];
-       struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
-       struct kvec qi_iov[1];
-       struct kvec close_iov[1];
+       struct kvec *rsp_iov;
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
@@ -2538,9 +2536,14 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
        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));
+       vars = kzalloc(sizeof(*vars), GFP_KERNEL);
+       if (!vars) {
+               rc = -ENOMEM;
+               goto out_free_path;
+       }
+       rqst = vars->rqst;
+       rsp_iov = vars->rsp_iov;
 
        /*
         * We can only call this for things we know are directories.
@@ -2549,8 +2552,7 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
                open_cached_dir(xid, tcon, path, cifs_sb, false,
                                &cfid); /* cfid null if open dir failed */
 
-       memset(&open_iov, 0, sizeof(open_iov));
-       rqst[0].rq_iov = open_iov;
+       rqst[0].rq_iov = vars->open_iov;
        rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
 
        oparms = (struct cifs_open_parms) {
@@ -2568,8 +2570,7 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
                goto qic_exit;
        smb2_set_next_command(tcon, &rqst[0]);
 
-       memset(&qi_iov, 0, sizeof(qi_iov));
-       rqst[1].rq_iov = qi_iov;
+       rqst[1].rq_iov = &vars->qi_iov;
        rqst[1].rq_nvec = 1;
 
        if (cfid) {
@@ -2596,8 +2597,7 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
                smb2_set_related(&rqst[1]);
        }
 
-       memset(&close_iov, 0, sizeof(close_iov));
-       rqst[2].rq_iov = close_iov;
+       rqst[2].rq_iov = &vars->close_iov;
        rqst[2].rq_nvec = 1;
 
        rc = SMB2_close_init(tcon, server,
@@ -2628,7 +2628,6 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
        *buftype = resp_buftype[1];
 
  qic_exit:
-       kfree(utf16_path);
        SMB2_open_free(&rqst[0]);
        SMB2_query_info_free(&rqst[1]);
        SMB2_close_free(&rqst[2]);
@@ -2636,6 +2635,9 @@ smb2_query_info_compound(const unsigned int xid, struct cifs_tcon *tcon,
        free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);
        if (cfid)
                close_cached_dir(cfid);
+       kfree(vars);
+out_free_path:
+       kfree(utf16_path);
        return rc;
 }