[PATCH 51/54] md/raid10: Adjust 22 checks for null pointers

From: SF Markus Elfring
Date: Thu Oct 06 2016 - 05:51:37 EST


From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 5 Oct 2016 21:36:43 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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The script "checkpatch.pl" pointed information out like the following.

Comparison to NULL could be written â

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid10.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 2181f53..82d79f5 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -734,10 +734,10 @@ static struct md_rdev *read_balance(struct r10conf *conf,
continue;
disk = r10_bio->devs[slot].devnum;
rdev = rcu_dereference(conf->mirrors[disk].replacement);
- if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
+ if (!rdev || test_bit(Faulty, &rdev->flags) ||
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
rdev = rcu_dereference(conf->mirrors[disk].rdev);
- if (rdev == NULL ||
+ if (!rdev ||
test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(In_sync, &rdev->flags) &&
@@ -1386,7 +1386,8 @@ static void __make_request(struct mddev *mddev, struct bio *bio)

if (r10_bio->devs[i].repl_bio) {
struct md_rdev *rdev = conf->mirrors[d].replacement;
- if (rdev == NULL) {
+
+ if (!rdev) {
/* Replacement just got moved to main 'rdev' */
smp_mb();
rdev = conf->mirrors[d].rdev;
@@ -1701,7 +1702,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
first = last = rdev->raid_disk;

if (rdev->saved_raid_disk >= first &&
- conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
+ !conf->mirrors[rdev->saved_raid_disk].rdev)
mirror = rdev->saved_raid_disk;
else
mirror = first;
@@ -1711,7 +1712,7 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
continue;
if (p->rdev) {
if (!test_bit(WantReplacement, &p->rdev->flags) ||
- p->replacement != NULL)
+ p->replacement)
continue;
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
@@ -1849,7 +1850,7 @@ static void end_sync_request(struct r10bio *r10_bio)
struct mddev *mddev = r10_bio->mddev;

while (atomic_dec_and_test(&r10_bio->remaining)) {
- if (r10_bio->master_bio == NULL) {
+ if (!r10_bio->master_bio) {
/* the primary of several recovery bios */
sector_t s = r10_bio->sectors;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
@@ -2515,7 +2516,7 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)

read_more:
rdev = read_balance(conf, r10_bio, &max_sectors);
- if (rdev == NULL) {
+ if (!rdev) {
pr_alert("%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev), b,
(unsigned long long)r10_bio->sector);
@@ -2587,7 +2588,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
for (m = 0; m < conf->copies; m++) {
int dev = r10_bio->devs[m].devnum;
rdev = conf->mirrors[dev].rdev;
- if (r10_bio->devs[m].bio == NULL)
+ if (!r10_bio->devs[m].bio)
continue;
if (!r10_bio->devs[m].bio->bi_error) {
rdev_clear_badblocks(
@@ -2602,7 +2603,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
md_error(conf->mddev, rdev);
}
rdev = conf->mirrors[dev].replacement;
- if (r10_bio->devs[m].repl_bio == NULL)
+ if (!r10_bio->devs[m].repl_bio)
continue;

if (!r10_bio->devs[m].repl_bio->bi_error) {
@@ -2631,7 +2632,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
- } else if (bio != NULL && bio->bi_error) {
+ } else if (bio && bio->bi_error) {
fail = true;
if (!narrow_write_error(r10_bio, m)) {
md_error(conf->mddev, rdev);
@@ -2816,7 +2817,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
* Allow skipping a full rebuild for incremental assembly
* of a clean array, like RAID1 does.
*/
- if (mddev->bitmap == NULL &&
+ if (!mddev->bitmap &&
mddev->recovery_cp == MaxSector &&
mddev->reshape_position == MaxSector &&
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
@@ -2945,10 +2946,10 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
mrdev = rcu_dereference(mirror->rdev);
mreplace = rcu_dereference(mirror->replacement);

- if ((mrdev == NULL ||
+ if ((!mrdev ||
test_bit(Faulty, &mrdev->flags) ||
test_bit(In_sync, &mrdev->flags)) &&
- (mreplace == NULL ||
+ (!mreplace ||
test_bit(Faulty, &mreplace->flags))) {
rcu_read_unlock();
continue;
@@ -2976,7 +2977,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
if (sync_blocks < max_sync)
max_sync = sync_blocks;
if (!must_sync &&
- mreplace == NULL &&
+ !mreplace &&
!conf->fullsync) {
/* yep, skip the sync_blocks here, but don't assume
* that there will never be anything to do here
@@ -3011,7 +3012,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
for (j = 0; j < conf->geo.raid_disks; j++) {
struct md_rdev *rdev = rcu_dereference(
conf->mirrors[j].rdev);
- if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
+ if (!rdev || test_bit(Faulty, &rdev->flags)) {
still_degraded = 1;
break;
}
@@ -3099,7 +3100,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
* this comment keeps human reviewers
* happy.
*/
- if (mreplace == NULL || bio == NULL ||
+ if (!mreplace || !bio ||
test_bit(Faulty, &mreplace->flags))
break;
bio_reset(bio);
@@ -3161,7 +3162,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
if (mreplace)
rdev_dec_pending(mreplace, mddev);
}
- if (biolist == NULL) {
+ if (!biolist) {
while (r10_bio) {
struct r10bio *rb2 = r10_bio;
r10_bio = (struct r10bio*) rb2->master_bio;
@@ -3214,7 +3215,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
bio->bi_error = -EIO;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
- if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
+ if (!rdev || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
@@ -3243,7 +3244,7 @@ static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
count++;

rdev = rcu_dereference(conf->mirrors[d].replacement);
- if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
+ if (!rdev || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
@@ -3565,7 +3566,7 @@ static int raid10_run(struct mddev *mddev)
int first = 1;
bool discard_supported = false;

- if (mddev->private == NULL) {
+ if (!mddev->private) {
conf = setup_conf(mddev);
if (IS_ERR(conf))
return PTR_ERR(conf);
@@ -4542,7 +4543,7 @@ static int handle_reshape_read_error(struct mddev *mddev,
int d = r10b->devs[slot].devnum;
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
sector_t addr;
- if (rdev == NULL ||
+ if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
goto failed;
--
2.10.1