LU-11121 mdt: take discard lock at cleanup stage

Call mdt_dom_check_and_discard() after mdt_object_unlock() to
avoid possible deadlock if some third lock is conflicting with
both like in the scenario below:
 thread1: mdt_object_lock() with some bits
 thread2: take conflicting lock and wait
 thread1: mdt_dom_check_and_discard() with bits conflicting
          with thread2 causes deadlock.

Patch enables dom layout in racer to test it on regular basis
Another minor update uses 'trap' in related tests.

Test-Parameters: mdssizegb=20 mdtcount=1 mdscount=1 testlist=sanity-dom,dom-performance,racer,racer,racer
Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: I63bedabb4a82cfa2f01e126d35dc8c2a89d64f56
Reviewed-on: https://review.whamcloud.com/29930
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/mdt/mdt_handler.c b/lustre/mdt/mdt_handler.c
index b0ad257..6550570 100644 (file)
--- a/lustre/mdt/mdt_handler.c
+++ b/lustre/mdt/mdt_handler.c
@@ -1840,7 +1840,7 @@ static int mdt_getattr_name_lock(struct mdt_thread_info *info,
                        LDLM_LOCK_PUT(lock);
                        mdt_object_put(info->mti_env, child);
                        /* NB: call the mdt_pack_size2body always after
-                        * mdt_object_put(), that is why this speacial
+                        * mdt_object_put(), that is why this special
                         * exit path is used. */
                        rc = mdt_pack_size2body(info, child_fid,
                                                &lhc->mlh_reg_lh);
@@ -1854,17 +1854,17 @@ static int mdt_getattr_name_lock(struct mdt_thread_info *info,
 
                        GOTO(out_parent, rc = 0);
                }
-        }
-        if (lock)
-                LDLM_LOCK_PUT(lock);
+       }
+       if (lock)
+               LDLM_LOCK_PUT(lock);
 
-        EXIT;
+       EXIT;
 out_child:
-        mdt_object_put(info->mti_env, child);
+       mdt_object_put(info->mti_env, child);
 out_parent:
-        if (lhp)
-                mdt_object_unlock(info, parent, lhp, 1);
-        return rc;
+       if (lhp)
+               mdt_object_unlock(info, parent, lhp, 1);
+       return rc;
 }
 
 /* normal handler: should release the child lock */

diff --git a/lustre/mdt/mdt_reint.c b/lustre/mdt/mdt_reint.c
index 4470fb0..5c451c0 100644 (file)
--- a/lustre/mdt/mdt_reint.c
+++ b/lustre/mdt/mdt_reint.c
@@ -847,7 +847,7 @@ static int mdt_reint_unlink(struct mdt_thread_info *info,
        struct mdt_lock_handle *child_lh;
        struct ldlm_enqueue_info *einfo = &info->mti_einfo;
        __u64 lock_ibits;
-       bool cos_incompat = false;
+       bool cos_incompat = false, discard = false;
        int no_name = 0;
        int rc;
 
@@ -1029,7 +1029,7 @@ relock:
                if (rc)
                        GOTO(out_stat, rc);
        } else {
-               mdt_dom_check_and_discard(info, mc);
+               discard = true;
        }
        mdt_handle_last_unlink(info, mc, ma);
 
@@ -1058,6 +1058,8 @@ out_stat:
 unlock_child:
        mdt_reint_striped_unlock(info, mc, child_lh, einfo, rc);
 put_child:
+       if (discard)
+               mdt_dom_check_and_discard(info, mc);
        mdt_object_put(info->mti_env, mc);
 unlock_parent:
        mdt_object_unlock(info, mp, parent_lh, rc);
@@ -1881,7 +1883,7 @@ static int mdt_reint_rename_internal(struct mdt_thread_info *info,
        struct lu_fid *new_fid = &info->mti_tmp_fid2;
        __u64 lock_ibits;
        bool reverse = false;
-       bool cos_incompat;
+       bool cos_incompat, discard = false;
        int rc;
        ENTRY;
 
@@ -2150,7 +2152,7 @@ relock:
                mdt_counter_incr(req, LPROC_MDT_RENAME);
                if (mnew) {
                        mdt_handle_last_unlink(info, mnew, ma);
-                       mdt_dom_check_and_discard(info, mnew);
+                       discard = true;
                }
 
                mdt_rename_counter_tally(info, info->mti_mdt, req,
@@ -2163,8 +2165,11 @@ relock:
 out_unlock_old:
        mdt_object_unlock(info, mold, lh_oldp, rc);
 out_put_new:
-       if (mnew != NULL)
+       if (mnew != NULL) {
+               if (discard)
+                       mdt_dom_check_and_discard(info, mnew);
                mdt_object_put(info->mti_env, mnew);
+       }
 out_put_old:
        mdt_object_put(info->mti_env, mold);
 out_unlock_parents:

diff --git a/lustre/tests/racer.sh b/lustre/tests/racer.sh
index ea70258..904ff71 100644 (file)
--- a/lustre/tests/racer.sh
+++ b/lustre/tests/racer.sh
@@ -53,7 +53,7 @@ RACER_ENABLE_STRIPED_DIRS=${RACER_ENABLE_STRIPED_DIRS:-false}
 RACER_ENABLE_MIGRATION=${RACER_ENABLE_MIGRATION:-false}
 RACER_ENABLE_SNAPSHOT=${RACER_ENABLE_SNAPSHOT:-true}
 RACER_ENABLE_PFL=${RACER_ENABLE_PFL:-true}
-RACER_ENABLE_DOM=${RACER_ENABLE_DOM:-false}
+RACER_ENABLE_DOM=${RACER_ENABLE_DOM:-true}
 RACER_ENABLE_FLR=${RACER_ENABLE_FLR:-true}
 
 check_progs_installed $CLIENTS $racer ||

diff --git a/lustre/tests/sanityn.sh b/lustre/tests/sanityn.sh
index 86367ae..b1b96de 100755 (executable)
--- a/lustre/tests/sanityn.sh
+++ b/lustre/tests/sanityn.sh
@@ -4371,19 +4371,19 @@ test_101a() {
        # to get layout
        $CHECKSTAT -t file $DIR1/$tfile
 
-       OLD_VAL=$(cat /proc/sys/vm/dirty_writeback_centisecs)
-       echo 0 > /proc/sys/vm/dirty_writeback_centisecs
-       echo $OLD_VAL
+       local old_wb=$(sysctl -n vm.dirty_writeback_centisecs)
+       sysctl -wq vm.dirty_writeback_centisecs=0
+
+       trap "sysctl -wq vm.dirty_writeback_centisecs=$old_wb" EXIT
 
        # open + IO lock
        dd if=/dev/zero of=$DIR1/$tfile bs=4096 count=1 ||
                error_noexit "Write fails"
        # must discard pages
        lctl set_param -n mdc.*.stats=clear
-       rm $DIR2/$tfile || error_noexit "Unlink fails"
-       local writes=$(lctl get_param -n mdc.*.stats | grep ost_write | wc -l)
-       echo $OLD_VAL > /proc/sys/vm/dirty_writeback_centisecs
+       rm $DIR2/$tfile || error "Unlink fails"
 
+       local writes=$(lctl get_param -n mdc.*.stats | grep ost_write | wc -l)
        [ $writes -eq 0 ] || error "Found WRITE RPC but expect none"
 }
 run_test 101a "Discard DoM data on unlink"
@@ -4397,18 +4397,18 @@ test_101b() {
        # to get layout
        $CHECKSTAT -t file $DIR1/$tfile
 
-       OLD_VAL=$(cat /proc/sys/vm/dirty_writeback_centisecs)
-       echo 0 > /proc/sys/vm/dirty_writeback_centisecs
-       echo $OLD_VAL
+       local old_wb=$(sysctl -n vm.dirty_writeback_centisecs)
+       sysctl -wq vm.dirty_writeback_centisecs=0
+
+       trap "sysctl -wq vm.dirty_writeback_centisecs=$old_wb" EXIT
 
        # open + IO lock
-       dd if=/dev/zero of=$DIR1/$tfile bs=4096 count=1 ||
-               error_noexit "Write fails"
+       dd if=/dev/zero of=$DIR1/$tfile bs=4096 count=1 || error "Write fails"
        # must discard pages
        lctl set_param -n mdc.*.stats=clear
-       mv $DIR2/${tfile}_2 $DIR2/$tfile || error_noexit "Rename fails"
+       mv $DIR2/${tfile}_2 $DIR2/$tfile || error "Rename fails"
+
        local writes=$(lctl get_param -n mdc.*.stats | grep ost_write | wc -l)
-       echo $OLD_VAL > /proc/sys/vm/dirty_writeback_centisecs
        [ $writes -eq 0 ] || error "Found WRITE RPC but expect none"
 }
 run_test 101b "Discard DoM data on rename"
@@ -4421,22 +4421,21 @@ test_101c() {
        # to get layout
        $CHECKSTAT -t file $DIR1/$tfile
 
-       OLD_VAL=$(cat /proc/sys/vm/dirty_writeback_centisecs)
-       echo 0 > /proc/sys/vm/dirty_writeback_centisecs
-       echo $OLD_VAL
+       local old_wb=$(sysctl -n vm.dirty_writeback_centisecs)
+       sysctl -wq vm.dirty_writeback_centisecs=0
+
+       trap "sysctl -wq vm.dirty_writeback_centisecs=$old_wb" EXIT
 
        # open + IO lock
-       dd if=/dev/zero of=$DIR1/$tfile bs=4096 count=1 ||
-               error_noexit "Write fails"
+       dd if=/dev/zero of=$DIR1/$tfile bs=4096 count=1 || error "Write fails"
        $MULTIOP $DIR1/$tfile O_c &
        MULTIOP_PID=$!
        sleep 1
        lctl set_param -n mdc.*.stats=clear
-       rm $DIR2/$tfile > /dev/null || error_noexit "Unlink fails"
-       kill -USR1 $MULTIOP_PID && wait $MULTIOP_PID ||
-               error_noexit "multiop failure"
+       rm $DIR2/$tfile > /dev/null || error "Unlink fails for opened file"
+       kill -USR1 $MULTIOP_PID && wait $MULTIOP_PID || error "multiop failure"
+
        local writes=$(lctl get_param -n mdc.*.stats | grep ost_write | wc -l)
-       echo $OLD_VAL > /proc/sys/vm/dirty_writeback_centisecs
        [ $writes -eq 0 ] || error "Found WRITE RPC but expect none"
 }
 run_test 101c "Discard DoM data on close-unlink"