From: NeilBrown <neilb@suse.de>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 005 of 9] md: Replace magic numbers in sb_dirty with well defined bit flags
Date: Mon, 31 Jul 2006 17:32:18 +1000 [thread overview]
Message-ID: <1060731073218.24482@suse.de> (raw)
In-Reply-To: 20060731172842.24323.patches@notabene
Instead of magic numbers (0,1,2,3) in sb_dirty, we have
some flags instead:
MD_CHANGE_DEVS
Some device state has changed requiring superblock update
on all devices.
MD_CHANGE_CLEAN
The array has transitions from 'clean' to 'dirty' or back,
requiring a superblock update on active devices, but possibly
not on spares
MD_CHANGE_PENDING
A superblock update is underway.
We wait for an update to complete by waiting for all flags to
be clear. A flag can be set at any time, even during an update,
without risk that the change will be lost.
Stop exporting md_update_sb - isn't needed.
Signed-off-by: Neil Brown <neilb@suse.de>
### Diffstat output
./drivers/md/md.c | 68 +++++++++++++++++++++++---------------------
./drivers/md/multipath.c | 3 -
./drivers/md/raid1.c | 2 -
./drivers/md/raid10.c | 2 -
./drivers/md/raid5.c | 8 ++---
./include/linux/raid/md.h | 1
./include/linux/raid/md_k.h | 6 +++
7 files changed, 49 insertions(+), 41 deletions(-)
diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c 2006-07-31 17:23:57.000000000 +1000
+++ ./drivers/md/md.c 2006-07-31 17:24:34.000000000 +1000
@@ -1587,7 +1587,7 @@ static void sync_sbs(mddev_t * mddev, in
}
}
-void md_update_sb(mddev_t * mddev)
+static void md_update_sb(mddev_t * mddev, int force_change)
{
int err;
struct list_head *tmp;
@@ -1597,18 +1597,25 @@ void md_update_sb(mddev_t * mddev)
repeat:
spin_lock_irq(&mddev->write_lock);
- sync_req = mddev->in_sync;
- mddev->utime = get_seconds();
- if (mddev->sb_dirty == 3)
+
+ set_bit(MD_CHANGE_PENDING, &mddev->flags);
+ if (test_and_clear_bit(MD_CHANGE_DEVS, &mddev->flags))
+ force_change = 1;
+ if (test_and_clear_bit(MD_CHANGE_CLEAN, &mddev->flags))
/* just a clean<-> dirty transition, possibly leave spares alone,
* though if events isn't the right even/odd, we will have to do
* spares after all
*/
nospares = 1;
+ if (force_change)
+ nospares = 0;
+
+ sync_req = mddev->in_sync;
+ mddev->utime = get_seconds();
/* If this is just a dirty<->clean transition, and the array is clean
* and 'events' is odd, we can roll back to the previous clean state */
- if (mddev->sb_dirty == 3
+ if (nospares
&& (mddev->in_sync && mddev->recovery_cp == MaxSector)
&& (mddev->events & 1))
mddev->events--;
@@ -1639,7 +1646,6 @@ repeat:
MD_BUG();
mddev->events --;
}
- mddev->sb_dirty = 2;
sync_sbs(mddev, nospares);
/*
@@ -1647,7 +1653,7 @@ repeat:
* nonpersistent superblocks
*/
if (!mddev->persistent) {
- mddev->sb_dirty = 0;
+ clear_bit(MD_CHANGE_PENDING, &mddev->flags);
spin_unlock_irq(&mddev->write_lock);
wake_up(&mddev->sb_wait);
return;
@@ -1684,20 +1690,20 @@ repeat:
break;
}
md_super_wait(mddev);
- /* if there was a failure, sb_dirty was set to 1, and we re-write super */
+ /* if there was a failure, MD_CHANGE_DEVS was set, and we re-write super */
spin_lock_irq(&mddev->write_lock);
- if (mddev->in_sync != sync_req|| mddev->sb_dirty == 1) {
+ if (mddev->in_sync != sync_req ||
+ test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
/* have to write it out again */
spin_unlock_irq(&mddev->write_lock);
goto repeat;
}
- mddev->sb_dirty = 0;
+ clear_bit(MD_CHANGE_PENDING, &mddev->flags);
spin_unlock_irq(&mddev->write_lock);
wake_up(&mddev->sb_wait);
}
-EXPORT_SYMBOL_GPL(md_update_sb);
/* words written to sysfs files may, or my not, be \n terminated.
* We want to accept with case. For this we use cmd_match.
@@ -1770,7 +1776,7 @@ state_store(mdk_rdev_t *rdev, const char
else {
mddev_t *mddev = rdev->mddev;
kick_rdev_from_array(rdev);
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
md_new_event(mddev);
err = 0;
}
@@ -2413,7 +2419,7 @@ array_state_store(mddev_t *mddev, const
spin_lock_irq(&mddev->write_lock);
if (atomic_read(&mddev->writes_pending) == 0) {
mddev->in_sync = 1;
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_CLEAN, &mddev->flags);
}
spin_unlock_irq(&mddev->write_lock);
} else {
@@ -2425,7 +2431,7 @@ array_state_store(mddev_t *mddev, const
case active:
if (mddev->pers) {
restart_array(mddev);
- mddev->sb_dirty = 0;
+ clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
wake_up(&mddev->sb_wait);
err = 0;
} else {
@@ -2530,7 +2536,7 @@ size_store(mddev_t *mddev, const char *b
if (mddev->pers) {
err = update_size(mddev, size);
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
} else {
if (mddev->size == 0 ||
mddev->size > size)
@@ -3098,8 +3104,8 @@ static int do_md_run(mddev_t * mddev)
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
- if (mddev->sb_dirty)
- md_update_sb(mddev);
+ if (mddev->flags)
+ md_update_sb(mddev, 0);
set_capacity(disk, mddev->array_size<<1);
@@ -3262,10 +3268,10 @@ static int do_md_stop(mddev_t * mddev, i
if (mddev->ro)
mddev->ro = 0;
}
- if (!mddev->in_sync || mddev->sb_dirty) {
+ if (!mddev->in_sync || mddev->flags) {
/* mark array as shutdown cleanly */
mddev->in_sync = 1;
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
}
if (mode == 1)
set_disk_ro(disk, 1);
@@ -3734,7 +3740,7 @@ static int hot_remove_disk(mddev_t * mdd
goto busy;
kick_rdev_from_array(rdev);
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
md_new_event(mddev);
return 0;
@@ -3811,7 +3817,7 @@ static int hot_add_disk(mddev_t * mddev,
rdev->raid_disk = -1;
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
/*
* Kick recovery, maybe this spare has to be added to the
@@ -3942,7 +3948,8 @@ static int set_array_info(mddev_t * mdde
mddev->max_disks = MD_SB_DISKS;
- mddev->sb_dirty = 1;
+ mddev->flags = 0;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
mddev->bitmap_offset = 0;
@@ -4111,7 +4118,7 @@ static int update_array_info(mddev_t *md
mddev->bitmap_offset = 0;
}
}
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
return rv;
}
@@ -4947,12 +4954,12 @@ void md_write_start(mddev_t *mddev, stru
spin_lock_irq(&mddev->write_lock);
if (mddev->in_sync) {
mddev->in_sync = 0;
- mddev->sb_dirty = 3;
+ set_bit(MD_CHANGE_CLEAN, &mddev->flags);
md_wakeup_thread(mddev->thread);
}
spin_unlock_irq(&mddev->write_lock);
}
- wait_event(mddev->sb_wait, mddev->sb_dirty==0);
+ wait_event(mddev->sb_wait, mddev->flags==0);
}
void md_write_end(mddev_t *mddev)
@@ -5222,7 +5229,6 @@ void md_do_sync(mddev_t *mddev)
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < mddev->curr_resync)
rdev->recovery_offset = mddev->curr_resync;
- mddev->sb_dirty = 1;
}
}
@@ -5279,7 +5285,7 @@ void md_check_recovery(mddev_t *mddev)
}
if ( ! (
- mddev->sb_dirty ||
+ mddev->flags ||
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
(mddev->safemode == 1) ||
@@ -5295,14 +5301,14 @@ void md_check_recovery(mddev_t *mddev)
if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
!mddev->in_sync && mddev->recovery_cp == MaxSector) {
mddev->in_sync = 1;
- mddev->sb_dirty = 3;
+ set_bit(MD_CHANGE_CLEAN, &mddev->flags);
}
if (mddev->safemode == 1)
mddev->safemode = 0;
spin_unlock_irq(&mddev->write_lock);
- if (mddev->sb_dirty)
- md_update_sb(mddev);
+ if (mddev->flags)
+ md_update_sb(mddev, 0);
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
@@ -5321,7 +5327,7 @@ void md_check_recovery(mddev_t *mddev)
/* activate any spares */
mddev->pers->spare_active(mddev);
}
- md_update_sb(mddev);
+ md_update_sb(mddev, 1);
/* if array is no-longer degraded, then any saved_raid_disk
* information must be scrapped
diff .prev/drivers/md/multipath.c ./drivers/md/multipath.c
--- .prev/drivers/md/multipath.c 2006-07-31 17:23:57.000000000 +1000
+++ ./drivers/md/multipath.c 2006-07-31 17:24:34.000000000 +1000
@@ -253,7 +253,7 @@ static void multipath_error (mddev_t *md
char b[BDEVNAME_SIZE];
clear_bit(In_sync, &rdev->flags);
set_bit(Faulty, &rdev->flags);
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
conf->working_disks--;
printk(KERN_ALERT "multipath: IO failure on %s,"
" disabling IO path. \n Operation continuing"
@@ -470,7 +470,6 @@ static int multipath_run (mddev_t *mddev
}
conf->raid_disks = mddev->raid_disks;
- mddev->sb_dirty = 1;
conf->mddev = mddev;
spin_lock_init(&conf->device_lock);
INIT_LIST_HEAD(&conf->retry_list);
diff .prev/drivers/md/raid1.c ./drivers/md/raid1.c
--- .prev/drivers/md/raid1.c 2006-07-31 17:24:24.000000000 +1000
+++ ./drivers/md/raid1.c 2006-07-31 17:24:34.000000000 +1000
@@ -966,7 +966,7 @@ static void error(mddev_t *mddev, mdk_rd
}
clear_bit(In_sync, &rdev->flags);
set_bit(Faulty, &rdev->flags);
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
" Operation continuing on %d devices\n",
bdevname(rdev->bdev,b), conf->working_disks);
diff .prev/drivers/md/raid10.c ./drivers/md/raid10.c
--- .prev/drivers/md/raid10.c 2006-07-31 17:24:34.000000000 +1000
+++ ./drivers/md/raid10.c 2006-07-31 17:24:34.000000000 +1000
@@ -960,7 +960,7 @@ static void error(mddev_t *mddev, mdk_rd
}
clear_bit(In_sync, &rdev->flags);
set_bit(Faulty, &rdev->flags);
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n"
" Operation continuing on %d devices\n",
bdevname(rdev->bdev,b), conf->working_disks);
diff .prev/drivers/md/raid5.c ./drivers/md/raid5.c
--- .prev/drivers/md/raid5.c 2006-07-31 17:23:57.000000000 +1000
+++ ./drivers/md/raid5.c 2006-07-31 17:24:34.000000000 +1000
@@ -696,7 +696,7 @@ static void error(mddev_t *mddev, mdk_rd
PRINTK("raid5: error called\n");
if (!test_bit(Faulty, &rdev->flags)) {
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
if (test_bit(In_sync, &rdev->flags)) {
conf->working_disks--;
mddev->degraded++;
@@ -2781,9 +2781,9 @@ static sector_t reshape_request(mddev_t
wait_event(conf->wait_for_overlap,
atomic_read(&conf->reshape_stripes)==0);
mddev->reshape_position = conf->expand_progress;
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
md_wakeup_thread(mddev->thread);
- wait_event(mddev->sb_wait, mddev->sb_dirty == 0 ||
+ wait_event(mddev->sb_wait, mddev->flags == 0 ||
kthread_should_stop());
spin_lock_irq(&conf->device_lock);
conf->expand_lo = mddev->reshape_position;
@@ -3605,7 +3605,7 @@ static int raid5_start_reshape(mddev_t *
mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
mddev->raid_disks = conf->raid_disks;
mddev->reshape_position = 0;
- mddev->sb_dirty = 1;
+ set_bit(MD_CHANGE_DEVS, &mddev->flags);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
diff .prev/include/linux/raid/md.h ./include/linux/raid/md.h
--- .prev/include/linux/raid/md.h 2006-07-31 17:23:57.000000000 +1000
+++ ./include/linux/raid/md.h 2006-07-31 17:24:34.000000000 +1000
@@ -93,7 +93,6 @@ extern int sync_page_io(struct block_dev
extern void md_do_sync(mddev_t *mddev);
extern void md_new_event(mddev_t *mddev);
-extern void md_update_sb(mddev_t * mddev);
#endif
diff .prev/include/linux/raid/md_k.h ./include/linux/raid/md_k.h
--- .prev/include/linux/raid/md_k.h 2006-07-31 17:23:57.000000000 +1000
+++ ./include/linux/raid/md_k.h 2006-07-31 17:24:34.000000000 +1000
@@ -114,7 +114,11 @@ struct mddev_s
dev_t unit;
int md_minor;
struct list_head disks;
- int sb_dirty;
+ unsigned long flags;
+#define MD_CHANGE_DEVS 0 /* Some device status has changed */
+#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
+#define MD_CHANGE_PENDING 2 /* superblock update in progress */
+
int ro;
struct gendisk *gendisk;
next prev parent reply other threads:[~2006-07-31 7:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-31 7:31 [PATCH 000 of 9] md: Introduction - assorted cleanup and minor fixes NeilBrown
2006-07-31 7:31 ` [PATCH 001 of 9] md: The scheduled removal of the START_ARRAY ioctl for md NeilBrown
2006-07-31 7:31 ` [PATCH 002 of 9] md: Fix a comment that is wrong in raid5.h NeilBrown
2006-07-31 7:32 ` [PATCH 003 of 9] md: Factor out part of raid1d into a separate function NeilBrown
2006-07-31 7:32 ` [PATCH 004 of 9] md: Factor out part of raid10d " NeilBrown
2006-08-01 17:15 ` Bill Davidsen
2006-08-01 20:27 ` Neil Brown
2006-07-31 7:32 ` NeilBrown [this message]
2006-07-31 15:33 ` [PATCH 005 of 9] md: Replace magic numbers in sb_dirty with well defined bit flags Ingo Oeser
2006-08-01 17:12 ` Bill Davidsen
2006-08-02 22:52 ` Doug Ledford
2006-07-31 7:32 ` [PATCH 006 of 9] md: Remove the working_disks and failed_disks from raid5 state data NeilBrown
2006-07-31 7:43 ` Michael Tokarev
2006-07-31 7:32 ` [PATCH 007 of 9] md: Remove 'working_disks' from raid10 state NeilBrown
2006-07-31 7:32 ` [PATCH 008 of 9] md: Remove working_disks from raid1 state data NeilBrown
2006-07-31 7:32 ` [PATCH 009 of 9] md: Improve locking around error handling NeilBrown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1060731073218.24482@suse.de \
--to=neilb@suse.de \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-raid@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.