The patch titled
md: fix issues with referencing rdev in md/raid1
has been removed from the -mm tree. Its filename is
md-fix-issues-with-referencing-rdev-in-md-raid1.patch
This patch was dropped because an updated version was merged
------------------------------------------------------
Subject: md: fix issues with referencing rdev in md/raid1
From: NeilBrown <neilb@xxxxxxx>
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 <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/md/raid1.c | 55 ++++++++++++++++++++++++++-----------------
1 files changed, 34 insertions(+), 21 deletions(-)
diff -puN drivers/md/raid1.c~md-fix-issues-with-referencing-rdev-in-md-raid1 drivers/md/raid1.c
--- a/drivers/md/raid1.c~md-fix-issues-with-referencing-rdev-in-md-raid1
+++ a/drivers/md/raid1.c
@@ -930,10 +930,13 @@ static void status(struct seq_file *seq,
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
- 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, "]");
}
@@ -976,7 +979,6 @@ 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) {
@@ -986,14 +988,17 @@ static void print_conf(conf_t *conf)
printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
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)
@@ -1009,17 +1014,17 @@ 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_and_set_bit(In_sync, &tmp->rdev->flags)) {
+ mdk_rdev_t *rdev = conf->mirrors[i].rdev;
+ if (rdev
+ && !test_bit(Faulty, &rdev->flags)
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded--;
@@ -1239,7 +1244,7 @@ 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
@@ -1259,6 +1264,10 @@ 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,
@@ -1376,6 +1385,11 @@ static void fix_read_error(conf_t *conf,
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) &&
@@ -1403,7 +1417,6 @@ static void fix_read_error(conf_t *conf,
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,
@@ -1429,7 +1442,8 @@ static void fix_read_error(conf_t *conf,
== 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",
@@ -1437,6 +1451,7 @@ static void fix_read_error(conf_t *conf,
(unsigned long long)sect +
rdev->data_offset,
bdevname(rdev->bdev, b));
+ }
}
}
sectors -= s;
@@ -1806,19 +1821,17 @@ 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;
}
_
Patches currently in -mm which might be from neilb@xxxxxxx are
lockdep-fix-blkdev_open-warning.patch
md-avoid-backward-event-updates-in-md-superblock-when-degraded.patch
md-fix-recent-breakage-of-md-raid1-array-checking.patch
vfs-destroy-the-dentries-contributed-by-a-superblock-on-unmounting.patch
knfsd-knfsd-add-some-missing-newlines-in-printks.patch
knfsd-knfsd-remove-an-unused-variable-from-e_show.patch
knfsd-knfsd-remove-an-unused-variable-from-auth_unix_lookup.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes.patch
knfsd-add-a-callback-for-when-last-rpc-thread-finishes-tidy.patch
knfsd-be-more-selective-in-which-sockets-lockd-listens-on.patch
knfsd-remove-nfsd_versbits-as-intermediate-storage-for-desired-versions.patch
knfsd-separate-out-some-parts-of-nfsd_svc-which-start-nfs-servers.patch
knfsd-separate-out-some-parts-of-nfsd_svc-which-start-nfs-servers-tweaks.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-tidy.patch
knfsd-define-new-nfsdfs-file-portlist-contains-list-of-ports-fix.patch
knfsd-allow-sockets-to-be-passed-to-nfsd-via-portlist.patch
knfsd-use-seq_start_token-instead-of-hardcoded-magic-void1.patch
knfsd-have-ext2-reject-file-handles-with-bad-inode-numbers-early.patch
knfsd-have-ext2-reject-file-handles-with-bad-inode-numbers-early-tidy.patch
knfsd-make-ext3-reject-filehandles-referring-to-invalid-inode-numbers.patch
knfsd-make-ext3-reject-filehandles-referring-to-invalid-inode-numbers-tidy.patch
knfsd-drop-serv-option-to-svc_recv-and-svc_process.patch
knfsd-drop-serv-option-to-svc_recv-and-svc_process-nfs-callback-fix-nfs-callback-fix.patch
knfsd-check-return-value-of-lockd_up-in-write_ports.patch
knfsd-move-makesock-failed-warning-into-make_socks.patch
knfsd-correctly-handle-error-condition-from-lockd_up.patch
knfsd-move-tempsock-aging-to-a-timer.patch
knfsd-move-tempsock-aging-to-a-timer-tidy.patch
knfsd-convert-sk_inuse-to-atomic_t.patch
knfsd-use-new-lock-for-svc_sock-deferred-list.patch
knfsd-convert-sk_reserved-to-atomic_t.patch
knfsd-test-and-set-sk_busy-atomically.patch
knfsd-split-svc_serv-into-pools.patch
knfsd-split-svc_serv-into-pools-fix.patch
knfsd-add-svc_get.patch
knfsd-add-svc_set_num_threads.patch
knfsd-use-svc_set_num_threads-to-manage-threads-in-knfsd.patch
knfsd-make-rpc-threads-pools-numa-aware.patch
knfsd-make-rpc-threads-pools-numa-aware-fix.patch
knfsd-allow-admin-to-set-nthreads-per-node.patch
nfsd-lockdep-annotation.patch
knfsd-nfsd-lockdep-annotation-fix.patch
knfsd-call-lockd_down-when-closing-a-socket-via-a-write-to-nfsd-portlist.patch
knfsd-protect-update-to-sn_nrthreads-with-lock_kernel.patch
knfsd-fixed-handling-of-lockd-fail-when-adding-nfsd-socket.patch
knfsd-replace-two-page-lists-in-struct-svc_rqst-with-one.patch
knfsd-avoid-excess-stack-usage-in-svc_tcp_recvfrom.patch
knfsd-prepare-knfsd-for-support-of-rsize-wsize-of-up-to-1mb-over-tcp.patch
knfsd-allow-max-size-of-nfsd-payload-to-be-configured.patch
knfsd-make-nfsd-readahead-params-cache-smp-friendly.patch
knfsd-knfsd-cache-ipmap-per-tcp-socket.patch
md-the-scheduled-removal-of-the-start_array-ioctl-for-md.patch
md-fix-a-comment-that-is-wrong-in-raid5h.patch
md-factor-out-part-of-raid1d-into-a-separate-function.patch
md-factor-out-part-of-raid10d-into-a-separate-function.patch
md-replace-magic-numbers-in-sb_dirty-with-well-defined-bit-flags.patch
md-remove-the-working_disks-and-failed_disks-from-raid5-state-data.patch
md-remove-working_disks-from-raid10-state.patch
md-remove-working_disks-from-raid1-state-data.patch
md-improve-locking-around-error-handling.patch
md-fix-issues-with-referencing-rdev-in-md-raid1.patch
md-new-sysfs-interface-for-setting-bits-in-the-write-intent-bitmap.patch
md-remove-unnecessary-variable-x-in-stripe_to_pdidx.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
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