Commit a0b58afa authored by Andriy Skulysh's avatar Andriy Skulysh Committed by Greg Kroah-Hartman
Browse files

staging/lustre/ptlrpc: Fix race during exp_flock_hash creation 

During race exp_flock_hash can be created 2 times.
It is created & assigned without any lock.

Move hash initialization from ldlm_flock_blocking_link()
to ldlm_init_export()

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2835
Lustre-change: http://review.whamcloud.com/5471


Signed-off-by: default avatarAndriy Skulysh <Andriy_Skulysh@xyratex.com>
Reviewed-by: default avatarAlexander Boyko <Alexander_Boyko@xyratex.com>
Reviewed-by: default avatarVitaly Fertman <Vitaly_Fertman@xyratex.com>
Tested-by: default avatarKyrylo Shatskyy <kyrylo_shatskyy@xyratex.com>
Reviewed-by: default avatarKeith Mannthey <keith.mannthey@intel.com>
Reviewed-by: default avatarPrakash Surya <surya1@llnl.gov>
Reviewed-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarPeng Tao <bergwolf@gmail.com>
Signed-off-by: default avatarAndreas Dilger <andreas.dilger@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c1f3d689

drivers/staging/lustre/lustre/ldlm/ldlm_flock.c

+8 −20
Original line number Diff line number Diff line
@@ -95,20 +95,12 @@ ldlm_flocks_overlap(struct ldlm_lock *lock, struct ldlm_lock *new) 
		lock->l_policy_data.l_flock.start));

}



static inline int ldlm_flock_blocking_link(struct ldlm_lock *req,

static inline void ldlm_flock_blocking_link(struct ldlm_lock *req,

					    struct ldlm_lock *lock)

{

	int rc = 0;



	/* For server only */

	if (req->l_export == NULL)

		return 0;



	if (unlikely(req->l_export->exp_flock_hash == NULL)) {

		rc = ldlm_init_flock_export(req->l_export);

		if (rc)

			goto error;

	}

		return;



	LASSERT(hlist_unhashed(&req->l_exp_flock_hash));
@@ -121,8 +113,6 @@ static inline int ldlm_flock_blocking_link(struct ldlm_lock *req, 
	cfs_hash_add(req->l_export->exp_flock_hash,

		     &req->l_policy_data.l_flock.owner,

		     &req->l_exp_flock_hash);

error:

	return rc;

}



static inline void ldlm_flock_blocking_unlink(struct ldlm_lock *req)
@@ -250,7 +240,6 @@ ldlm_process_flock_lock(struct ldlm_lock *req, __u64 *flags, int first_enq, 
	int overlaps = 0;

	int splitted = 0;

	const struct ldlm_callback_suite null_cbs = { NULL };

	int rc;



	CDEBUG(D_DLMTRACE, "flags %#llx owner "LPU64" pid %u mode %u start "

	       LPU64" end "LPU64"\n", *flags,
@@ -328,12 +317,8 @@ reprocess: 


			/* add lock to blocking list before deadlock

			 * check to prevent race */

			rc = ldlm_flock_blocking_link(req, lock);

			if (rc) {

				ldlm_flock_destroy(req, mode, *flags);

				*err = rc;

				return LDLM_ITER_STOP;

			}

			ldlm_flock_blocking_link(req, lock);



			if (ldlm_flock_deadlock(req, lock)) {

				ldlm_flock_blocking_unlink(req);

				ldlm_flock_destroy(req, mode, *flags);
@@ -813,6 +798,9 @@ static cfs_hash_ops_t ldlm_export_flock_ops = { 


int ldlm_init_flock_export(struct obd_export *exp)

{

	if (strcmp(exp->exp_obd->obd_type->typ_name, LUSTRE_MDT_NAME) != 0)

		return 0;



	exp->exp_flock_hash =

		cfs_hash_create(obd_uuid2str(&exp->exp_client_uuid),

				HASH_EXP_LOCK_CUR_BITS,

drivers/staging/lustre/lustre/ldlm/ldlm_lockd.c

+8 −0
Original line number Diff line number Diff line
@@ -964,6 +964,7 @@ static cfs_hash_ops_t ldlm_export_lock_ops = { 


int ldlm_init_export(struct obd_export *exp)

{

	int rc;

	exp->exp_lock_hash =

		cfs_hash_create(obd_uuid2str(&exp->exp_client_uuid),

				HASH_EXP_LOCK_CUR_BITS,
@@ -977,7 +978,14 @@ int ldlm_init_export(struct obd_export *exp) 
	if (!exp->exp_lock_hash)

		return -ENOMEM;



	rc = ldlm_init_flock_export(exp);

	if (rc)

		GOTO(err, rc);



	return 0;

err:

	ldlm_destroy_export(exp);

	return rc;

}

EXPORT_SYMBOL(ldlm_init_export);

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