[linux-cifs-client] Re: [PATCH 03/13] cifs: allow get_cifs_acl to be called without an inode

[Jeff Layton]

On Mon, 11 May 2009 16:56:21 -0400
Christoph Hellwig <hch at infradead.org> wrote:

> On Mon, May 11, 2009 at 04:24:22PM -0400, Jeff Layton wrote:
> > We'll need this later when we restructure cifs_get_inode_info.
> > 
> > Signed-off-by: Jeff Layton <jlayton at redhat.com>
> > ---
> >  fs/cifs/cifsacl.c |   25 ++++++-------------------
> >  1 files changed, 6 insertions(+), 19 deletions(-)
> > 
> >  static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
> > -				       const char *path, const __u16 *pfid)
> > +				      const char *path, const __u16 *pfid)
> >  {
> >  	struct cifsFileInfo *open_file = NULL;
> > -	bool unlock_file = false;
> >  	int xid;
> >  	int rc = -EIO;
> >  	__u16 fid;
> > -	struct super_block *sb;
> > -	struct cifs_sb_info *cifs_sb;
> >  	struct cifs_ntsd *pntsd = NULL;
> > +	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
> 
> This isn't going to work with a NULL inode.
> 

Oops. Good catch!

> But this whole set_cifs_acl function is a real mess anyway and needs
> some splitting up.  What about the untested patch below?
> 

Looks good. I'll plan to incorporate this or something close to it on
the next respin.

Thanks for the review so far.

> 
> Index: linux-2.6/fs/cifs/cifsacl.c
> ===================================================================
> --- linux-2.6.orig/fs/cifs/cifsacl.c	2009-05-11 22:35:29.841784452 +0200
> +++ linux-2.6/fs/cifs/cifsacl.c	2009-05-11 22:55:19.465660251 +0200
> @@ -552,67 +552,65 @@ static int build_sec_desc(struct cifs_nt
>  	return rc;
>  }
>  
> -
> -/* Retrieve an ACL from the server */
> -static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
> -				       const char *path, const __u16 *pfid)
> +static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
> +		__u16 fid, u32 *pacllen)
>  {
> -	struct cifsFileInfo *open_file = NULL;
> -	bool unlock_file = false;
> -	int xid;
> -	int rc = -EIO;
> -	__u16 fid;
> -	struct super_block *sb;
> -	struct cifs_sb_info *cifs_sb;
>  	struct cifs_ntsd *pntsd = NULL;
> +	int xid, rc;
>  
> -	cFYI(1, ("get mode from ACL for %s", path));
> +	xid = GetXid();
> +	rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, &pntsd, pacllen);
> +	FreeXid(xid);
>  
> -	if (inode == NULL)
> -		return NULL;
>  
> -	xid = GetXid();
> -	if (pfid == NULL)
> -		open_file = find_readable_file(CIFS_I(inode));
> -	else
> -		fid = *pfid;
> +	cFYI(1, ("GetCIFSACL rc = %d ACL len %d", rc, *pacllen));
> +	return pntsd;
> +}
>  
> -	sb = inode->i_sb;
> -	if (sb == NULL) {
> -		FreeXid(xid);
> -		return NULL;
> -	}
> -	cifs_sb = CIFS_SB(sb);
> +static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
> +		const char *path, u32 *pacllen)
> +{
> +	struct cifs_ntsd *pntsd = NULL;
> +	int oplock = 0;
> +	int xid, rc;
> +	__u16 fid;
>  
> -	if (open_file) {
> -		unlock_file = true;
> -		fid = open_file->netfid;
> -	} else if (pfid == NULL) {
> -		int oplock = 0;
> -		/* open file */
> -		rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
> -				READ_CONTROL, 0, &fid, &oplock, NULL,
> -				cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
> -					CIFS_MOUNT_MAP_SPECIAL_CHR);
> -		if (rc != 0) {
> -			cERROR(1, ("Unable to open file to get ACL"));
> -			FreeXid(xid);
> -			return NULL;
> -		}
> +	xid = GetXid();
> +
> +	rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN, READ_CONTROL, 0,
> +			 &fid, &oplock, NULL, cifs_sb->local_nls,
> +			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
> +	if (rc) {
> +		cERROR(1, ("Unable to open file to get ACL"));
> +		goto out;
>  	}
>  
>  	rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, &pntsd, pacllen);
>  	cFYI(1, ("GetCIFSACL rc = %d ACL len %d", rc, *pacllen));
> -	if (unlock_file == true) /* find_readable_file increments ref count */
> -		atomic_dec(&open_file->wrtPending);
> -	else if (pfid == NULL) /* if opened above we have to close the handle */
> -		CIFSSMBClose(xid, cifs_sb->tcon, fid);
> -	/* else handle was passed in by caller */
>  
> +	CIFSSMBClose(xid, cifs_sb->tcon, fid);
> + out:
>  	FreeXid(xid);
>  	return pntsd;
>  }
>  
> +/* Retrieve an ACL from the server */
> +static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
> +				       const char *path)
> +{
> +	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
> +	struct cifs_ntsd *pntsd = NULL;
> +	struct cifsFileInfo *open_file;
> +
> +	open_file = find_readable_file(CIFS_I(inode));
> +	if (!open_file)
> +		return get_cifs_acl_by_path(cifs_sb, path, pacllen);
> +
> +	pntsd = get_cifs_acl_by_fid(cifs_sb, open_file->netfid, pacllen);
> +	atomic_dec(&open_file->wrtPending);
> +	return pntsd;
> +}
> +
>  /* Set an ACL on the server */
>  static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
>  				struct inode *inode, const char *path)
> @@ -675,7 +673,13 @@ void acl_to_uid_mode(struct inode *inode
>  	int rc = 0;
>  
>  	cFYI(DBG2, ("converting ACL to mode for %s", path));
> -	pntsd = get_cifs_acl(&acllen, inode, path, pfid);
> +
> +	if (pfid) {
> +		pntsd = get_cifs_acl_by_fid(CIFS_SB(inode->i_sb), *pfid,
> +					    &acllen);
> +	} else {
> +		pntsd = get_cifs_acl(&acllen, inode, path);
> +	}
>  
>  	/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
>  	if (pntsd)
> @@ -698,7 +702,7 @@ int mode_to_acl(struct inode *inode, con
>  	cFYI(DBG2, ("set ACL from mode for %s", path));
>  
>  	/* Get the security descriptor */
> -	pntsd = get_cifs_acl(&secdesclen, inode, path, NULL);
> +	pntsd = get_cifs_acl(&secdesclen, inode, path);
>  
>  	/* Add three ACEs for owner, group, everyone getting rid of
>  	   other ACEs as chmod disables ACEs and set the security descriptor */



-- 
Jeff Layton <jlayton at redhat.com>