md: Introduction - some revised/reordered patches.

PATCH In review NeilBrown 2 participants 7 messages Aug 27, 2006 – Aug 28, 2006 MD RAID

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NeilBrown

author

2006-08-27 23:49 UTC #0 lore raw

PATCH 1/1 md: Introduction - some revised/reordered patches.

Following are revisions of 4 patches currently in -rc4-mm3 which reorder the last to be the first, as that first should go to 2.6.18, but the others don't need to.

The patches are:

md-fix-issues-with-referencing-rdev-in-md-raid1.patch md-factor-out-part-of-raid1d-into-a-separate-function.patch md-remove-working_disks-from-raid1-state-data.patch md-improve-locking-around-error-handling.patch

The first one listed above was at the end of the list, and should go into 2.6.18.

Thanks,
NeilBrown

NeilBrown

author

2006-08-27 23:49 UTC #1 lore raw

PATCH 1/1 md: Fix issues with referencing rdev in md/raid1

We need to be careful when referencing mirrors[i].rdev. so it can disappear under us at various times.

So:
fix a couple of problem places.
comment a couple of non-problem places
move an 'atomic_add' which deferences rdev down a little
way to some where where it is sure to not be NULL.

Signed-off-by Neil Brown <[email protected]>

---

drivers/md/raid1.c +35 ~~-22~~

Index: mm-quilt/drivers/md/raid1.c
===================================================================
@@ -930,10 +930,13 @@ static void status(struct seq_file *seq,
 
 	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
 						conf->working_disks);
-	for (i = 0; i < conf->raid_disks; i++)
+	rcu_read_lock();
+	for (i = 0; i < conf->raid_disks; i++) {
+		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
 		seq_printf(seq, "%s",
-			      conf->mirrors[i].rdev &&
-			      test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
+			   rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+	}
+	rcu_read_unlock();
 	seq_printf(seq, "]");
 }

@@ -975,7 +978,6 @@ static void error(mddev_t *mddev, mdk_rd
 static void print_conf(conf_t *conf)
 {
 	int i;
-	mirror_info_t *tmp;
 
 	printk("RAID1 conf printout:\n");
 	if (!conf) {

@@ -985,14 +987,17 @@ static void print_conf(conf_t *conf)
 	printk(" --- wd:%d rd:%d\n", conf->working_disks,
 		conf->raid_disks);
 
+	rcu_read_lock();
 	for (i = 0; i < conf->raid_disks; i++) {
 		char b[BDEVNAME_SIZE];
-		tmp = conf->mirrors + i;
-		if (tmp->rdev)
+		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+		if (rdev)
 			printk(" disk %d, wo:%d, o:%d, dev:%s\n",
-				i, !test_bit(In_sync, &tmp->rdev->flags), !test_bit(Faulty, &tmp->rdev->flags),
-				bdevname(tmp->rdev->bdev,b));
+			       i, !test_bit(In_sync, &rdev->flags),
+			       !test_bit(Faulty, &rdev->flags),
+			       bdevname(rdev->bdev,b));
 	}
+	rcu_read_unlock();
 }
 
 static void close_sync(conf_t *conf)

@@ -1008,20 +1013,20 @@ static int raid1_spare_active(mddev_t *m
 {
 	int i;
 	conf_t *conf = mddev->private;
-	mirror_info_t *tmp;
 
 	/*
 	 * Find all failed disks within the RAID1 configuration 
-	 * and mark them readable
+	 * and mark them readable.
+	 * Called under mddev lock, so rcu protection not needed.
 	 */
 	for (i = 0; i < conf->raid_disks; i++) {
-		tmp = conf->mirrors + i;
-		if (tmp->rdev 
-		    && !test_bit(Faulty, &tmp->rdev->flags)
-		    && !test_bit(In_sync, &tmp->rdev->flags)) {
+		mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+		if (rdev
+		    && !test_bit(Faulty, &rdev->flags)
+		    && !test_bit(In_sync, &rdev->flags)) {
 			conf->working_disks++;
 			mddev->degraded--;
-			set_bit(In_sync, &tmp->rdev->flags);
+			set_bit(In_sync, &rdev->flags);
 		}
 	}

@@ -1237,7 +1242,7 @@ static void sync_request_write(mddev_t *
 		/* ouch - failed to read all of that.
 		 * Try some synchronous reads of other devices to get
 		 * good data, much like with normal read errors.  Only
-		 * read into the pages we already have so they we don't
+		 * read into the pages we already have so we don't
 		 * need to re-issue the read request.
 		 * We don't need to freeze the array, because being in an
 		 * active sync request, there is no normal IO, and

@@ -1257,6 +1262,10 @@ static void sync_request_write(mddev_t *
 				s = PAGE_SIZE >> 9;
 			do {
 				if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
+					/* No rcu protection needed here devices
+					 * can only be removed when no resync is
+					 * active, and resync is currently active
+					 */
 					rdev = conf->mirrors[d].rdev;
 					if (sync_page_io(rdev->bdev,
 							 sect + rdev->data_offset,

@@ -1463,6 +1472,11 @@ static void raid1d(mddev_t *mddev)
 					s = PAGE_SIZE >> 9;
 
 				do {
+					/* Note: no rcu protection needed here
+					 * as this is synchronous in the raid1d thread
+					 * which is the thread that might remove
+					 * a device.  If raid1d ever becomes multi-threaded....
+					 */
 					rdev = conf->mirrors[d].rdev;
 					if (rdev &&
 					    test_bit(In_sync, &rdev->flags) &&

@@ -1486,7 +1500,6 @@ static void raid1d(mddev_t *mddev)
 							d = conf->raid_disks;
 						d--;
 						rdev = conf->mirrors[d].rdev;
-						atomic_add(s, &rdev->corrected_errors);
 						if (rdev &&
 						    test_bit(In_sync, &rdev->flags)) {
 							if (sync_page_io(rdev->bdev,

@@ -1509,9 +1522,11 @@ static void raid1d(mddev_t *mddev)
 									 s<<9, conf->tmppage, READ) == 0)
 								/* Well, this device is dead */
 								md_error(mddev, rdev);
-							else
+							else {
+								atomic_add(s, &rdev->corrected_errors);
 								printk(KERN_INFO "raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
 								       mdname(mddev), s, (unsigned long long)(sect + rdev->data_offset), bdevname(rdev->bdev, b));
+							}
 						}
 					}
 				} else {

@@ -1787,19 +1802,17 @@ static sector_t sync_request(mddev_t *md
 		for (i=0; i<conf->raid_disks; i++) {
 			bio = r1_bio->bios[i];
 			if (bio->bi_end_io == end_sync_read) {
-				md_sync_acct(conf->mirrors[i].rdev->bdev, nr_sectors);
+				md_sync_acct(bio->bi_bdev, nr_sectors);
 				generic_make_request(bio);
 			}
 		}
 	} else {
 		atomic_set(&r1_bio->remaining, 1);
 		bio = r1_bio->bios[r1_bio->read_disk];
-		md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev,
-			     nr_sectors);
+		md_sync_acct(bio->bi_bdev, nr_sectors);
 		generic_make_request(bio);
 
 	}
-
 	return nr_sectors;
 }

NeilBrown

author

2006-08-27 23:49 UTC #2 lore raw

PATCH 1/1 md: Factor out part of raid1d into a separate function

In reply to NeilBrown

From: NeilBrown <[email protected]>

raid1d has toooo many nested block, so take the fix_read_error functionality out into a separate function.

Signed-off-by Neil Brown <[email protected]>

---

 drivers/md/raid1.c |  161 +++++++++++++++++++++++--------------------
 1 file changed, 89 insertions(+), 72 deletions(-)

drivers/md/raid1.c +95 ~~-78~~

Index: mm-quilt/drivers/md/raid1.c
===================================================================
@@ -1368,6 +1368,95 @@ static void sync_request_write(mddev_t *
  *	3.	Performs writes following reads for array syncronising.
  */
 
+static void fix_read_error(conf_t *conf, int read_disk,
+			   sector_t sect, int sectors)
+{
+	mddev_t *mddev = conf->mddev;
+	while(sectors) {
+		int s = sectors;
+		int d = read_disk;
+		int success = 0;
+		int start;
+		mdk_rdev_t *rdev;
+
+		if (s > (PAGE_SIZE>>9))
+			s = PAGE_SIZE >> 9;
+
+		do {
+			/* Note: no rcu protection needed here
+			 * as this is synchronous in the raid1d thread
+			 * which is the thread that might remove
+			 * a device.  If raid1d ever becomes multi-threaded....
+			 */
+			rdev = conf->mirrors[d].rdev;
+			if (rdev &&
+			    test_bit(In_sync, &rdev->flags) &&
+			    sync_page_io(rdev->bdev,
+					 sect + rdev->data_offset,
+					 s<<9,
+					 conf->tmppage, READ))
+				success = 1;
+			else {
+				d++;
+				if (d == conf->raid_disks)
+					d = 0;
+			}
+		} while (!success && d != read_disk);
+
+		if (!success) {
+			/* Cannot read from anywhere -- bye bye array */
+			md_error(mddev, conf->mirrors[read_disk].rdev);
+			break;
+		}
+		/* write it back and re-read */
+		start = d;
+		while (d != read_disk) {
+			if (d==0)
+				d = conf->raid_disks;
+			d--;
+			rdev = conf->mirrors[d].rdev;
+			if (rdev &&
+			    test_bit(In_sync, &rdev->flags)) {
+				if (sync_page_io(rdev->bdev,
+						 sect + rdev->data_offset,
+						 s<<9, conf->tmppage, WRITE)
+				    == 0)
+					/* Well, this device is dead */
+					md_error(mddev, rdev);
+			}
+		}
+		d = start;
+		while (d != read_disk) {
+			char b[BDEVNAME_SIZE];
+			if (d==0)
+				d = conf->raid_disks;
+			d--;
+			rdev = conf->mirrors[d].rdev;
+			if (rdev &&
+			    test_bit(In_sync, &rdev->flags)) {
+				if (sync_page_io(rdev->bdev,
+						 sect + rdev->data_offset,
+						 s<<9, conf->tmppage, READ)
+				    == 0)
+					/* Well, this device is dead */
+					md_error(mddev, rdev);
+				else {
+					atomic_add(s, &rdev->corrected_errors);
+					printk(KERN_INFO
+					       "raid1:%s: read error corrected "
+					       "(%d sectors at %llu on %s)\n",
+					       mdname(mddev), s,
+					       (unsigned long long)sect +
+					           rdev->data_offset,
+					       bdevname(rdev->bdev, b));
+				}
+			}
+		}
+		sectors -= s;
+		sect += s;
+	}
+}
+
 static void raid1d(mddev_t *mddev)
 {
 	r1bio_t *r1_bio;

@@ -1460,86 +1549,14 @@ static void raid1d(mddev_t *mddev)
 			 * This is all done synchronously while the array is
 			 * frozen
 			 */
-			sector_t sect = r1_bio->sector;
-			int sectors = r1_bio->sectors;
-			freeze_array(conf);
-			if (mddev->ro == 0) while(sectors) {
-				int s = sectors;
-				int d = r1_bio->read_disk;
-				int success = 0;
-
-				if (s > (PAGE_SIZE>>9))
-					s = PAGE_SIZE >> 9;
-
-				do {
-					/* Note: no rcu protection needed here
-					 * as this is synchronous in the raid1d thread
-					 * which is the thread that might remove
-					 * a device.  If raid1d ever becomes multi-threaded....
-					 */
-					rdev = conf->mirrors[d].rdev;
-					if (rdev &&
-					    test_bit(In_sync, &rdev->flags) &&
-					    sync_page_io(rdev->bdev,
-							 sect + rdev->data_offset,
-							 s<<9,
-							 conf->tmppage, READ))
-						success = 1;
-					else {
-						d++;
-						if (d == conf->raid_disks)
-							d = 0;
-					}
-				} while (!success && d != r1_bio->read_disk);
-
-				if (success) {
-					/* write it back and re-read */
-					int start = d;
-					while (d != r1_bio->read_disk) {
-						if (d==0)
-							d = conf->raid_disks;
-						d--;
-						rdev = conf->mirrors[d].rdev;
-						if (rdev &&
-						    test_bit(In_sync, &rdev->flags)) {
-							if (sync_page_io(rdev->bdev,
-									 sect + rdev->data_offset,
-									 s<<9, conf->tmppage, WRITE) == 0)
-								/* Well, this device is dead */
-								md_error(mddev, rdev);
-						}
-					}
-					d = start;
-					while (d != r1_bio->read_disk) {
-						if (d==0)
-							d = conf->raid_disks;
-						d--;
-						rdev = conf->mirrors[d].rdev;
-						if (rdev &&
-						    test_bit(In_sync, &rdev->flags)) {
-							if (sync_page_io(rdev->bdev,
-									 sect + rdev->data_offset,
-									 s<<9, conf->tmppage, READ) == 0)
-								/* Well, this device is dead */
-								md_error(mddev, rdev);
-							else {
-								atomic_add(s, &rdev->corrected_errors);
-								printk(KERN_INFO "raid1:%s: read error corrected (%d sectors at %llu on %s)\n",
-								       mdname(mddev), s, (unsigned long long)(sect + rdev->data_offset), bdevname(rdev->bdev, b));
-							}
-						}
-					}
-				} else {
-					/* Cannot read from anywhere -- bye bye array */
-					md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
-					break;
-				}
-				sectors -= s;
-				sect += s;
+			if (mddev->ro == 0) {
+				freeze_array(conf);
+				fix_read_error(conf, r1_bio->read_disk,
+					       r1_bio->sector,
+					       r1_bio->sectors);
+				unfreeze_array(conf);
 			}
 
-			unfreeze_array(conf);
-
 			bio = r1_bio->bios[r1_bio->read_disk];
 			if ((disk=read_balance(conf, r1_bio)) == -1) {
 				printk(KERN_ALERT "raid1: %s: unrecoverable I/O"

NeilBrown

author

2006-08-27 23:49 UTC #3 lore raw

PATCH 1/1 md: Remove working_disks from raid1 state data

In reply to NeilBrown

From: NeilBrown <[email protected]>

It is equivalent to conf->raid_disks - conf->mddev->degraded.

Signed-off-by Neil Brown <[email protected]>

---

 drivers/md/raid1.c         |   28 ++++++++++++----------------
 include/linux/raid/raid1.h |    1 -
 2 files changed, 12 insertions(+), 17 deletions(-)

drivers/md/raid1.c +12 ~~-16~~

Index: mm-quilt/drivers/md/raid1.c
===================================================================
@@ -271,7 +271,7 @@ static int raid1_end_read_request(struct
 	 */
 	update_head_pos(mirror, r1_bio);
 
-	if (uptodate || conf->working_disks <= 1) {
+	if (uptodate || (conf->raid_disks - conf->mddev->degraded) <= 1) {
 		/*
 		 * Set R1BIO_Uptodate in our master bio, so that
 		 * we will return a good error code for to the higher

@@ -929,7 +929,7 @@ static void status(struct seq_file *seq,
 	int i;
 
 	seq_printf(seq, " [%d/%d] [", conf->raid_disks,
-						conf->working_disks);
+		   conf->raid_disks - mddev->degraded);
 	rcu_read_lock();
 	for (i = 0; i < conf->raid_disks; i++) {
 		mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);

@@ -953,7 +953,7 @@ static void error(mddev_t *mddev, mdk_rd
 	 * else mark the drive as failed
 	 */
 	if (test_bit(In_sync, &rdev->flags)
-	    && conf->working_disks == 1)
+	    && (conf->raid_disks - mddev->degraded) == 1)
 		/*
 		 * Don't fail the drive, act as though we were just a
 		 * normal single drive

@@ -961,7 +961,6 @@ static void error(mddev_t *mddev, mdk_rd
 		return;
 	if (test_bit(In_sync, &rdev->flags)) {
 		mddev->degraded++;
-		conf->working_disks--;
 		/*
 		 * if recovery is running, make sure it aborts.
 		 */

@@ -972,7 +971,7 @@ static void error(mddev_t *mddev, mdk_rd
 	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);
+		bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
 }
 
 static void print_conf(conf_t *conf)

@@ -984,7 +983,7 @@ static void print_conf(conf_t *conf)
 		printk("(!conf)\n");
 		return;
 	}
-	printk(" --- wd:%d rd:%d\n", conf->working_disks,
+	printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
 		conf->raid_disks);
 
 	rcu_read_lock();

@@ -1024,7 +1023,6 @@ static int raid1_spare_active(mddev_t *m
 		if (rdev
 		    && !test_bit(Faulty, &rdev->flags)
 		    && !test_bit(In_sync, &rdev->flags)) {
-			conf->working_disks++;
 			mddev->degraded--;
 			set_bit(In_sync, &rdev->flags);
 		}

@@ -1901,15 +1899,11 @@ static int run(mddev_t *mddev)
 			blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
 
 		disk->head_position = 0;
-		if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags))
-			conf->working_disks++;
 	}
 	conf->raid_disks = mddev->raid_disks;
 	conf->mddev = mddev;
 	spin_lock_init(&conf->device_lock);
 	INIT_LIST_HEAD(&conf->retry_list);
-	if (conf->working_disks == 1)
-		mddev->recovery_cp = MaxSector;
 
 	spin_lock_init(&conf->resync_lock);
 	init_waitqueue_head(&conf->wait_barrier);

@@ -1917,11 +1911,6 @@ static int run(mddev_t *mddev)
 	bio_list_init(&conf->pending_bio_list);
 	bio_list_init(&conf->flushing_bio_list);
 
-	if (!conf->working_disks) {
-		printk(KERN_ERR "raid1: no operational mirrors for %s\n",
-			mdname(mddev));
-		goto out_free_conf;
-	}
 
 	mddev->degraded = 0;
 	for (i = 0; i < conf->raid_disks; i++) {

@@ -1934,6 +1923,13 @@ static int run(mddev_t *mddev)
 			mddev->degraded++;
 		}
 	}
+	if (mddev->degraded == conf->raid_disks) {
+		printk(KERN_ERR "raid1: no operational mirrors for %s\n",
+			mdname(mddev));
+		goto out_free_conf;
+	}
+	if (conf->raid_disks - mddev->degraded == 1)
+		mddev->recovery_cp = MaxSector;
 
 	/*
 	 * find the first working one and use it as a starting point

include/linux/raid/raid1.h +0 -1

Index: mm-quilt/include/linux/raid/raid1.h
===================================================================
@@ -30,7 +30,6 @@ struct r1_private_data_s {
 	mddev_t			*mddev;
 	mirror_info_t		*mirrors;
 	int			raid_disks;
-	int			working_disks;
 	int			last_used;
 	sector_t		next_seq_sect;
 	spinlock_t		device_lock;

NeilBrown

author

2006-08-27 23:49 UTC #4 lore raw

PATCH 1/1 md: Improve locking around error handling

In reply to NeilBrown

From: NeilBrown <[email protected]>

The error handling routines don't use proper locking, and so two concurrent errors could trigger a problem.

So:
- use test-and-set and test-and-clear to synchonise

    the In_sync bits with the ->degraded count

- use the spinlock to protect updates to the degraded count (could use an atomic_t but that would be a bigger change in code, and isn't really justified)
- remove un-necessary locking in raid5

Signed-off-by Neil Brown <[email protected]>

---

 drivers/md/raid1.c  |   16 +++++++++++-----
 drivers/md/raid10.c |   12 ++++++++----
 drivers/md/raid5.c  |   20 ++++++++++++--------
 3 files changed, 31 insertions(+), 17 deletions(-)

drivers/md/raid1.c +11 -5

Index: mm-quilt/drivers/md/raid1.c
===================================================================
@@ -959,14 +959,16 @@ static void error(mddev_t *mddev, mdk_rd
 		 * normal single drive
 		 */
 		return;
-	if (test_bit(In_sync, &rdev->flags)) {
+	if (test_and_clear_bit(In_sync, &rdev->flags)) {
+		unsigned long flags;
+		spin_lock_irqsave(&conf->device_lock, flags);
 		mddev->degraded++;
+		spin_unlock_irqrestore(&conf->device_lock, flags);
 		/*
 		 * if recovery is running, make sure it aborts.
 		 */
 		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
 	}
-	clear_bit(In_sync, &rdev->flags);
 	set_bit(Faulty, &rdev->flags);
 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
 	printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"

@@ -1022,9 +1024,11 @@ static int raid1_spare_active(mddev_t *m
 		mdk_rdev_t *rdev = conf->mirrors[i].rdev;
 		if (rdev
 		    && !test_bit(Faulty, &rdev->flags)
-		    && !test_bit(In_sync, &rdev->flags)) {
+		    && !test_and_set_bit(In_sync, &rdev->flags)) {
+			unsigned long flags;
+			spin_lock_irqsave(&conf->device_lock, flags);
 			mddev->degraded--;
-			set_bit(In_sync, &rdev->flags);
+			spin_unlock_irqrestore(&conf->device_lock, flags);
 		}
 	}

@@ -2048,7 +2052,7 @@ static int raid1_reshape(mddev_t *mddev)
 	mirror_info_t *newmirrors;
 	conf_t *conf = mddev_to_conf(mddev);
 	int cnt, raid_disks;
-
+	unsigned long flags;
 	int d, d2;
 
 	/* Cannot change chunk_size, layout, or level */

@@ -2107,7 +2111,9 @@ static int raid1_reshape(mddev_t *mddev)
 	kfree(conf->poolinfo);
 	conf->poolinfo = newpoolinfo;
 
+	spin_lock_irqsave(&conf->device_lock, flags);
 	mddev->degraded += (raid_disks - conf->raid_disks);
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 	conf->raid_disks = mddev->raid_disks = raid_disks;
 	mddev->delta_disks = 0;

drivers/md/raid10.c +8 -4

Index: mm-quilt/drivers/md/raid10.c
===================================================================
@@ -950,14 +950,16 @@ static void error(mddev_t *mddev, mdk_rd
 		 * really dead" tests...
 		 */
 		return;
-	if (test_bit(In_sync, &rdev->flags)) {
+	if (test_and_clear_bit(In_sync, &rdev->flags)) {
+		unsigned long flags;
+		spin_lock_irqsave(&conf->device_lock, flags);
 		mddev->degraded++;
+		spin_unlock_irqrestore(&conf->device_lock, flags);
 		/*
 		 * if recovery is running, make sure it aborts.
 		 */
 		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
 	}
-	clear_bit(In_sync, &rdev->flags);
 	set_bit(Faulty, &rdev->flags);
 	set_bit(MD_CHANGE_DEVS, &mddev->flags);
 	printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n"

@@ -1033,9 +1035,11 @@ static int raid10_spare_active(mddev_t *
 		tmp = conf->mirrors + i;
 		if (tmp->rdev
 		    && !test_bit(Faulty, &tmp->rdev->flags)
-		    && !test_bit(In_sync, &tmp->rdev->flags)) {
+		    && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
+			unsigned long flags;
+			spin_lock_irqsave(&conf->device_lock, flags);
 			mddev->degraded--;
-			set_bit(In_sync, &tmp->rdev->flags);
+			spin_unlock_irqrestore(&conf->device_lock, flags);
 		}
 	}

drivers/md/raid5.c +12 -8

Index: mm-quilt/drivers/md/raid5.c
===================================================================
@@ -636,7 +636,6 @@ static int raid5_end_write_request (stru
  	struct stripe_head *sh = bi->bi_private;
 	raid5_conf_t *conf = sh->raid_conf;
 	int disks = sh->disks, i;
-	unsigned long flags;
 	int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags);
 
 	if (bi->bi_size)

@@ -654,7 +653,6 @@ static int raid5_end_write_request (stru
 		return 0;
 	}
 
-	spin_lock_irqsave(&conf->device_lock, flags);
 	if (!uptodate)
 		md_error(conf->mddev, conf->disks[i].rdev);

@@ -662,8 +660,7 @@ static int raid5_end_write_request (stru
 	
 	clear_bit(R5_LOCKED, &sh->dev[i].flags);
 	set_bit(STRIPE_HANDLE, &sh->state);
-	__release_stripe(conf, sh);
-	spin_unlock_irqrestore(&conf->device_lock, flags);
+	release_stripe(sh);
 	return 0;
 }

@@ -697,9 +694,11 @@ static void error(mddev_t *mddev, mdk_rd
 
 	if (!test_bit(Faulty, &rdev->flags)) {
 		set_bit(MD_CHANGE_DEVS, &mddev->flags);
-		if (test_bit(In_sync, &rdev->flags)) {
+		if (test_and_clear_bit(In_sync, &rdev->flags)) {
+			unsigned long flags;
+			spin_lock_irqsave(&conf->device_lock, flags);
 			mddev->degraded++;
-			clear_bit(In_sync, &rdev->flags);
+			spin_unlock_irqrestore(&conf->device_lock, flags);
 			/*
 			 * if recovery was running, make sure it aborts.
 			 */

@@ -3419,9 +3418,11 @@ static int raid5_spare_active(mddev_t *m
 		tmp = conf->disks + i;
 		if (tmp->rdev
 		    && !test_bit(Faulty, &tmp->rdev->flags)
-		    && !test_bit(In_sync, &tmp->rdev->flags)) {
+		    && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
+			unsigned long flags;
+			spin_lock_irqsave(&conf->device_lock, flags);
 			mddev->degraded--;
-			set_bit(In_sync, &tmp->rdev->flags);
+			spin_unlock_irqrestore(&conf->device_lock, flags);
 		}
 	}
 	print_raid5_conf(conf);

@@ -3557,6 +3558,7 @@ static int raid5_start_reshape(mddev_t *
 	struct list_head *rtmp;
 	int spares = 0;
 	int added_devices = 0;
+	unsigned long flags;
 
 	if (mddev->degraded ||
 	    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))

@@ -3598,7 +3600,9 @@ static int raid5_start_reshape(mddev_t *
 				break;
 		}
 
+	spin_lock_irqsave(&conf->device_lock, flags);
 	mddev->degraded = (conf->raid_disks - conf->previous_raid_disks) - added_devices;
+	spin_unlock_irqrestore(&conf->device_lock, flags);
 	mddev->raid_disks = conf->raid_disks;
 	mddev->reshape_position = 0;
 	set_bit(MD_CHANGE_DEVS, &mddev->flags);

Jeff Breidenbach

2006-08-28 00:06 UTC #5 lore raw

Recommended kernel?

In reply to NeilBrown

I'm thinking about upgrading from Linux 2.6.14 to some newer kernel - probably to whatever is in Debian unstable. They're all basically safe for md and RAID1, right? No gotcha kernel versions to especially avoid?

--Jeff

Neil Brown

author

2006-08-28 00:11 UTC #6 lore raw

Re: Recommended kernel?

Quoted 3 lines · On Sunday August 27, [email protected] wrote:

I'm thinking about upgrading from Linux 2.6.14 to some newer kernel - probably to whatever is in Debian unstable. They're all basically safe for md and RAID1, right? No gotcha kernel versions to especially avoid?

2.6.17.11 should be fine.

NeilBrown