[PATCH 14/20] staging/lustre/llite: Solve a race to access lli_has_smd in read case

green
2015-02-02T02:53:34Z

From: Jinshan Xiong <jinshan.xiong@intel.com>

In vvp_io_read_lock(), it used to decide if to add read lock by
checking lli_has_smd. Accessing lli_has_smd is racy when an empty
file is turned into raid0, therefore, it may result in read requests
are issued without corresponding lock.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-on: http://review.whamcloud.com/12139
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5062
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
---
drivers/staging/lustre/lustre/include/lclient.h | 1 +
drivers/staging/lustre/lustre/lclient/lcommon_cl.c | 6 ++++++
drivers/staging/lustre/lustre/llite/vvp_io.c | 15 +++++----------
drivers/staging/lustre/lustre/llite/vvp_lock.c | 1 +
4 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/lustre/lustre/include/lclient.h b/drivers/staging/lustre/lustre/include/lclient.h
index 316500c..c5c3a8d 100644
--- a/drivers/staging/lustre/lustre/include/lclient.h
+++ b/drivers/staging/lustre/lustre/include/lclient.h
@@ -325,6 +325,7 @@ void ccc_lock_fini(const struct lu_env *env, struct cl_lock_slice *slice);
int ccc_lock_enqueue(const struct lu_env *env,
const struct cl_lock_slice *slice,
struct cl_io *io, __u32 enqflags);
+int ccc_lock_use(const struct lu_env *env, const struct cl_lock_slice *slice);
int ccc_lock_unuse(const struct lu_env *env, const struct cl_lock_slice *slice);
int ccc_lock_wait(const struct lu_env *env, const struct cl_lock_slice *slice);
int ccc_lock_fits_into(const struct lu_env *env,
diff --git a/drivers/staging/lustre/lustre/lclient/lcommon_cl.c b/drivers/staging/lustre/lustre/lclient/lcommon_cl.c
index 24d26ab..23095bb 100644
--- a/drivers/staging/lustre/lustre/lclient/lcommon_cl.c
+++ b/drivers/staging/lustre/lustre/lclient/lcommon_cl.c
@@ -586,6 +586,12 @@ int ccc_lock_enqueue(const struct lu_env *env,
return 0;
}

+int ccc_lock_use(const struct lu_env *env, const struct cl_lock_slice *slice)
+{
+ CLOBINVRNT(env, slice->cls_obj, ccc_object_invariant(slice->cls_obj));
+ return 0;
+}
+
int ccc_lock_unuse(const struct lu_env *env, const struct cl_lock_slice *slice)
{
CLOBINVRNT(env, slice->cls_obj, ccc_object_invariant(slice->cls_obj));
diff --git a/drivers/staging/lustre/lustre/llite/vvp_io.c b/drivers/staging/lustre/lustre/llite/vvp_io.c
index 930f601..ce54b76 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_io.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_io.c
@@ -307,18 +307,13 @@ static int vvp_io_rw_lock(const struct lu_env *env, struct cl_io *io,
static int vvp_io_read_lock(const struct lu_env *env,
const struct cl_io_slice *ios)
{
- struct cl_io *io = ios->cis_io;
- struct ll_inode_info *lli = ll_i2info(ccc_object_inode(io->ci_obj));
+ struct cl_io *io = ios->cis_io;
+ struct cl_io_rw_common *rd = &io->u.ci_rd.rd;
int result;

- /* XXX: Layer violation, we shouldn't see lsm at llite level. */
- if (lli->lli_has_smd) /* lsm-less file doesn't need to lock */
- result = vvp_io_rw_lock(env, io, CLM_READ,
- io->u.ci_rd.rd.crw_pos,
- io->u.ci_rd.rd.crw_pos +
- io->u.ci_rd.rd.crw_count - 1);
- else
- result = 0;
+ result = vvp_io_rw_lock(env, io, CLM_READ, rd->crw_pos,
+ rd->crw_pos + rd->crw_count - 1);
+
return result;
}

diff --git a/drivers/staging/lustre/lustre/llite/vvp_lock.c b/drivers/staging/lustre/lustre/llite/vvp_lock.c
index 372633e..f354e82 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_lock.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_lock.c
@@ -71,6 +71,7 @@ static const struct cl_lock_operations vvp_lock_ops = {
.clo_fini = ccc_lock_fini,
.clo_enqueue = ccc_lock_enqueue,
.clo_wait = ccc_lock_wait,
+ .clo_use = ccc_lock_use,
.clo_unuse = ccc_lock_unuse,
.clo_fits_into = ccc_lock_fits_into,
.clo_state = ccc_lock_state,
--
2.1.0