| Message ID | 1342831308-18815-7-git-send-email-sage@inktank.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com> On Fri, Jul 20, 2012 at 5:41 PM, Sage Weil <sage@inktank.com> wrote: > Previously, we were opportunistically initializing the bio_iter if it > appeared to be uninitialized in the middle of the read path. The problem > is that a sequence like: > > - start reading message > - initialize bio_iter > - read half a message > - messenger fault, reconnect > - restart reading message > - ** bio_iter now non-NULL, not reinitialized ** > - read past end of bio, crash > > Instead, initialize the bio_iter unconditionally when we allocate/claim > the message for read. > > Signed-off-by: Sage Weil <sage@inktank.com> > --- > net/ceph/messenger.c | 11 ++++++----- > 1 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c > index e24310e..efa369f 100644 > --- a/net/ceph/messenger.c > +++ b/net/ceph/messenger.c > @@ -1876,6 +1876,11 @@ static int read_partial_message(struct ceph_connection *con) > else > con->in_msg_pos.page_pos = 0; > con->in_msg_pos.data_pos = 0; > + > +#ifdef CONFIG_BLOCK > + if (m->bio) > + init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); > +#endif > } > > /* front */ > @@ -1892,10 +1897,6 @@ static int read_partial_message(struct ceph_connection *con) > if (ret <= 0) > return ret; > } > -#ifdef CONFIG_BLOCK > - if (m->bio && !m->bio_iter) > - init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); > -#endif > > /* (page) data */ > while (con->in_msg_pos.data_pos < data_len) { > @@ -1906,7 +1907,7 @@ static int read_partial_message(struct ceph_connection *con) > return ret; > #ifdef CONFIG_BLOCK > } else if (m->bio) { > - > + BUG_ON(!m->bio_iter); > ret = read_partial_message_bio(con, > &m->bio_iter, &m->bio_seg, > data_len, do_datacrc); > -- > 1.7.9 > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07/20/2012 07:41 PM, Sage Weil wrote: > Previously, we were opportunistically initializing the bio_iter if it > appeared to be uninitialized in the middle of the read path. The problem > is that a sequence like: > > - start reading message > - initialize bio_iter > - read half a message > - messenger fault, reconnect > - restart reading message > - ** bio_iter now non-NULL, not reinitialized ** > - read past end of bio, crash > > Instead, initialize the bio_iter unconditionally when we allocate/claim > the message for read. > > Signed-off-by: Sage Weil <sage@inktank.com> This seems to be similar to this recent change to the writing side of things: commit 43643528cce60ca184fe8197efa8e8da7c89a037 Author: Yan, Zheng <zheng.z.yan@intel.com> rbd: Clear ceph_msg->bio_iter for retransmitted message In any case, this is the place where a new message is being initialized, so it makes sense that this is where you re-init the bio_iter pointer. Reviewed-by: Alex Elder <elder@inktank.com> > --- > net/ceph/messenger.c | 11 ++++++----- > 1 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c > index e24310e..efa369f 100644 > --- a/net/ceph/messenger.c > +++ b/net/ceph/messenger.c > @@ -1876,6 +1876,11 @@ static int read_partial_message(struct ceph_connection *con) > else > con->in_msg_pos.page_pos = 0; > con->in_msg_pos.data_pos = 0; > + > +#ifdef CONFIG_BLOCK > + if (m->bio) > + init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); > +#endif > } > > /* front */ > @@ -1892,10 +1897,6 @@ static int read_partial_message(struct ceph_connection *con) > if (ret <= 0) > return ret; > } > -#ifdef CONFIG_BLOCK > - if (m->bio && !m->bio_iter) > - init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); > -#endif > > /* (page) data */ > while (con->in_msg_pos.data_pos < data_len) { > @@ -1906,7 +1907,7 @@ static int read_partial_message(struct ceph_connection *con) > return ret; > #ifdef CONFIG_BLOCK > } else if (m->bio) { > - > + BUG_ON(!m->bio_iter); > ret = read_partial_message_bio(con, > &m->bio_iter, &m->bio_seg, > data_len, do_datacrc); > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index e24310e..efa369f 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1876,6 +1876,11 @@ static int read_partial_message(struct ceph_connection *con) else con->in_msg_pos.page_pos = 0; con->in_msg_pos.data_pos = 0; + +#ifdef CONFIG_BLOCK + if (m->bio) + init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); +#endif } /* front */ @@ -1892,10 +1897,6 @@ static int read_partial_message(struct ceph_connection *con) if (ret <= 0) return ret; } -#ifdef CONFIG_BLOCK - if (m->bio && !m->bio_iter) - init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); -#endif /* (page) data */ while (con->in_msg_pos.data_pos < data_len) { @@ -1906,7 +1907,7 @@ static int read_partial_message(struct ceph_connection *con) return ret; #ifdef CONFIG_BLOCK } else if (m->bio) { - + BUG_ON(!m->bio_iter); ret = read_partial_message_bio(con, &m->bio_iter, &m->bio_seg, data_len, do_datacrc);
Previously, we were opportunistically initializing the bio_iter if it appeared to be uninitialized in the middle of the read path. The problem is that a sequence like: - start reading message - initialize bio_iter - read half a message - messenger fault, reconnect - restart reading message - ** bio_iter now non-NULL, not reinitialized ** - read past end of bio, crash Instead, initialize the bio_iter unconditionally when we allocate/claim the message for read. Signed-off-by: Sage Weil <sage@inktank.com> --- net/ceph/messenger.c | 11 ++++++----- 1 files changed, 6 insertions(+), 5 deletions(-)