From: NeilBrown <neilb@suse.de>
To: linux-raid@vger.kernel.org
Subject: [md PATCH 18/26] md: remove mddev_lock from rdev_attr_show()
Date: Wed, 04 Feb 2015 08:42:29 +1100 [thread overview]
Message-ID: <20150203214229.3448.28776.stgit@notabene.brown> (raw)
In-Reply-To: <20150203213948.3448.80258.stgit@notabene.brown>
No rdev attributes need locking for 'show', though
state_show() might benefit from ensuring it sees a
consistent set of flags.
None even use rdev->mddev, so testing for it isn't really
needed and it certainly doesn't need to be held constant.
So improve state_show() and remove the locking.
Signed-off-by: NeilBrown <neilb@suse.de>
---
drivers/md/md.c | 36 ++++++++++++++----------------------
1 file changed, 14 insertions(+), 22 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b7f48238a92d..cbbac7b7238a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2419,40 +2419,41 @@ state_show(struct md_rdev *rdev, char *page)
{
char *sep = "";
size_t len = 0;
+ unsigned long flags = ACCESS_ONCE(rdev->flags);
- if (test_bit(Faulty, &rdev->flags) ||
+ if (test_bit(Faulty, &flags) ||
rdev->badblocks.unacked_exist) {
len+= sprintf(page+len, "%sfaulty",sep);
sep = ",";
}
- if (test_bit(In_sync, &rdev->flags)) {
+ if (test_bit(In_sync, &flags)) {
len += sprintf(page+len, "%sin_sync",sep);
sep = ",";
}
- if (test_bit(WriteMostly, &rdev->flags)) {
+ if (test_bit(WriteMostly, &flags)) {
len += sprintf(page+len, "%swrite_mostly",sep);
sep = ",";
}
- if (test_bit(Blocked, &rdev->flags) ||
+ if (test_bit(Blocked, &flags) ||
(rdev->badblocks.unacked_exist
- && !test_bit(Faulty, &rdev->flags))) {
+ && !test_bit(Faulty, &flags))) {
len += sprintf(page+len, "%sblocked", sep);
sep = ",";
}
- if (!test_bit(Faulty, &rdev->flags) &&
- !test_bit(In_sync, &rdev->flags)) {
+ if (!test_bit(Faulty, &flags) &&
+ !test_bit(In_sync, &flags)) {
len += sprintf(page+len, "%sspare", sep);
sep = ",";
}
- if (test_bit(WriteErrorSeen, &rdev->flags)) {
+ if (test_bit(WriteErrorSeen, &flags)) {
len += sprintf(page+len, "%swrite_error", sep);
sep = ",";
}
- if (test_bit(WantReplacement, &rdev->flags)) {
+ if (test_bit(WantReplacement, &flags)) {
len += sprintf(page+len, "%swant_replacement", sep);
sep = ",";
}
- if (test_bit(Replacement, &rdev->flags)) {
+ if (test_bit(Replacement, &flags)) {
len += sprintf(page+len, "%sreplacement", sep);
sep = ",";
}
@@ -2965,21 +2966,12 @@ rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
- struct mddev *mddev = rdev->mddev;
- ssize_t rv;
if (!entry->show)
return -EIO;
-
- rv = mddev ? mddev_lock(mddev) : -EBUSY;
- if (!rv) {
- if (rdev->mddev == NULL)
- rv = -EBUSY;
- else
- rv = entry->show(rdev, page);
- mddev_unlock(mddev);
- }
- return rv;
+ if (!rdev->mddev)
+ return -EBUSY;
+ return entry->show(rdev, page);
}
static ssize_t
next prev parent reply other threads:[~2015-02-03 21:42 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-03 21:42 [md PATCH 00/26] Pending md patches NeilBrown
2015-02-03 21:42 ` [md PATCH 04/26] md/raid5: need_this_block: start simplifying the last two conditions NeilBrown
2015-02-03 21:42 ` [md PATCH 06/26] md: rename mddev->write_lock to mddev->lock NeilBrown
2015-02-03 21:42 ` [md PATCH 02/26] md/raid5: separate large if clause out of fetch_block() NeilBrown
2015-02-03 21:42 ` [md PATCH 01/26] md: do_release_stripe(): No need to call md_wakeup_thread() twice NeilBrown
2015-02-03 21:42 ` [md PATCH 03/26] md/raid5: separate out the easy conditions in need_this_block NeilBrown
2015-02-03 21:42 ` [md PATCH 05/26] md/raid5: need_this_block: tidy/fix last condition NeilBrown
2015-02-03 21:42 ` [md PATCH 12/26] md: level_store: group all important changes into one place NeilBrown
2015-02-03 21:42 ` [md PATCH 10/26] md: split detach operation out from ->stop NeilBrown
2015-02-03 21:42 ` [md PATCH 13/26] md: protect ->pers changes with mddev->lock NeilBrown
2015-02-03 21:42 ` [md PATCH 14/26] md/bitmap: protect clearing of ->bitmap by mddev->lock NeilBrown
2015-02-03 21:42 ` [md PATCH 19/26] md: remove unnecessary 'buf' from get_bitmap_file NeilBrown
2015-02-03 21:42 ` [md PATCH 16/26] md/raid5: use ->lock to protect accessing raid5 sysfs attributes NeilBrown
2015-02-03 21:42 ` [md PATCH 07/26] md: make ->congested robust against personality changes NeilBrown
2015-02-03 21:42 ` [md PATCH 11/26] md: rename ->stop to ->free NeilBrown
2015-02-03 21:42 ` [md PATCH 15/26] md: remove need for mddev_lock() in md_seq_show() NeilBrown
2015-02-03 21:42 ` [md PATCH 09/26] md/linear: remove rcu protections in favour of suspend/resume NeilBrown
2015-02-03 21:42 ` [md PATCH 17/26] md: remove mddev_lock() from md_attr_show() NeilBrown
2015-02-03 21:42 ` [md PATCH 20/26] md: tidy up set_bitmap_file NeilBrown
2015-02-03 21:42 ` [md PATCH 08/26] md: make merge_bvec_fn more robust in face of personality changes NeilBrown
2015-02-03 21:42 ` NeilBrown [this message]
2015-02-03 21:42 ` [md PATCH 23/26] md: use mddev->lock to protect updates to resync_{min, max} NeilBrown
2015-02-03 21:42 ` [md PATCH 24/26] md: move mddev_lock and related to md.h NeilBrown
2015-02-03 21:42 ` [md PATCH 25/26] md: make reconfig_mutex optional for writes to md sysfs files NeilBrown
2015-02-03 21:42 ` [md PATCH 22/26] md: minor cleanup in safe_delay_store NeilBrown
2015-02-03 21:42 ` [md PATCH 26/26] md: wakeup thread upon rdev_dec_pending() NeilBrown
2015-02-03 21:42 ` [md PATCH 21/26] md: move GET_BITMAP_FILE ioctl out from mddev_lock NeilBrown
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