From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: [PATCH 05/16] rbd: define dup_token() Date: Wed, 11 Jul 2012 09:01:23 -0500 Message-ID: <4FFD8733.9090305@inktank.com> References: <4FFD847C.7070205@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:63502 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757702Ab2GKOB1 (ORCPT ); Wed, 11 Jul 2012 10:01:27 -0400 Received: by mail-yx0-f174.google.com with SMTP id l2so1225622yen.19 for ; Wed, 11 Jul 2012 07:01:27 -0700 (PDT) In-Reply-To: <4FFD847C.7070205@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Define a new function dup_token(), to be used during argument parsing for making dynamically-allocated copies of tokens being parsed. For now, no gfp_flags parameter is defined (GFP_KERNEL is used) but it could be easily be added if needed. Signed-off-by: Alex Elder --- drivers/block/rbd.c | 36 ++++++++++++++++++++++++++++++++++++ 1 files changed, 36 insertions(+), 0 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 2ae3bb0..63c132f 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2281,6 +2281,42 @@ static inline size_t copy_token(const char **buf, } /* + * Finds the next token in *buf, dynamically allocates a buffer big + * enough to hold a copy of it, and copies the token into the new + * buffer. The copy is guaranteed to be terminated with '\0'. Note + * that a duplicate buffer is created even for a zero-length token. + * + * Returns a pointer to the newly-allocated duplicate, or a null + * pointer if memory for the duplicate was not available. If + * the lenp argument is a non-null pointer, the length of the token + * (not including the '\0') is returned in *lenp. + * + * If successful, the *buf pointer will be updated to point beyond + * the end of the found token. + * + * Note: For now, the memory is allocated using GFP_KERNEL. + */ +static inline char *dup_token(const char **buf, size_t *lenp) +{ + char *dup; + size_t len; + + len = next_token(buf); + dup = kmalloc(len + 1, GFP_KERNEL); + if (!dup) + return NULL; + + memcpy(dup, *buf, len); + *(dup + len) = '\0'; + *buf += len; + + if (lenp) + *lenp = len; + + return dup; +} + +/* * This fills in the pool_name, obj, obj_len, snap_name, obj_len, * rbd_dev, rbd_md_name, and name fields of the given rbd_dev, based * on the list of monitor addresses and other options provided via -- 1.7.5.4