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Commit 2a6fba6d authored by Eric Sandeen's avatar Eric Sandeen Committed by Dave Chinner
Browse files

xfs: only return -errno or success from attr ->put_listent 



Today, the put_listent formatters return either 1 or 0; if
they return 1, some callers treat this as an error and return
it up the stack, despite "1" not being a valid (negative)
error code.

The intent seems to be that if the input buffer is full,
we set seen_enough or set count = -1, and return 1;
but some callers check the return before checking the
seen_enough or count fields of the context.

Fix this by only returning non-zero for actual errors
encountered, and rely on the caller to first check the
return value, then check the values in the context to
decide what to do.

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent f55532a0

fs/xfs/xfs_attr.h

+1 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ typedef struct attrlist_cursor_kern { 
 *========================================================================*/





/* Return 0 on success, or -errno; other state communicated via *context */

typedef int (*put_listent_func_t)(struct xfs_attr_list_context *, int,

			      unsigned char *, int, int, unsigned char *);

fs/xfs/xfs_attr_list.c

+3 −5
Original line number Diff line number Diff line
@@ -108,16 +108,14 @@ xfs_attr_shortform_list(xfs_attr_list_context_t *context) 
					   (int)sfe->namelen,

					   (int)sfe->valuelen,

					   &sfe->nameval[sfe->namelen]);



			if (error)

				return error;

			/*

			 * Either search callback finished early or

			 * didn't fit it all in the buffer after all.

			 */

			if (context->seen_enough)

				break;



			if (error)

				return error;

			sfe = XFS_ATTR_SF_NEXTENTRY(sfe);

		}

		trace_xfs_attr_list_sf_all(context);
@@ -581,7 +579,7 @@ xfs_attr_put_listent( 
		trace_xfs_attr_list_full(context);

		alist->al_more = 1;

		context->seen_enough = 1;

		return 1;

		return 0;

	}



	aep = (attrlist_ent_t *)&context->alist[context->firstu];

fs/xfs/xfs_xattr.c

+10 −4
Original line number Diff line number Diff line
@@ -146,7 +146,7 @@ __xfs_xattr_put_listent( 
	arraytop = context->count + prefix_len + namelen + 1;

	if (arraytop > context->firstu) {

		context->count = -1;	/* insufficient space */

		return 1;

		return 0;

	}

	offset = (char *)context->alist + context->count;

	strncpy(offset, prefix, prefix_len);
@@ -221,11 +221,15 @@ xfs_xattr_put_listent( 
}



ssize_t

xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)

xfs_vn_listxattr(

	struct dentry	*dentry,

	char		*data,

	size_t		size)

{

	struct xfs_attr_list_context context;

	struct attrlist_cursor_kern cursor = { 0 };

	struct inode	*inode = d_inode(dentry);

	int		error;



	/*

	 * First read the regular on-disk attributes.
@@ -239,7 +243,9 @@ xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size) 
	context.firstu = context.bufsize;

	context.put_listent = xfs_xattr_put_listent;



	xfs_attr_list_int(&context);

	error = xfs_attr_list_int(&context);

	if (error)

		return error;

	if (context.count < 0)

		return -ERANGE;