drbd: RCU for disk_conf
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index b8ea480..ea62838 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -384,7 +384,8 @@
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (get_ldev_if_state(mdev, D_CONSISTENT)) {
- fp = max_t(enum drbd_fencing_p, fp, mdev->ldev->dc.fencing);
+ fp = max_t(enum drbd_fencing_p, fp,
+ rcu_dereference(mdev->ldev->disk_conf)->fencing);
put_ldev(mdev);
}
}
@@ -678,7 +679,12 @@
struct drbd_backing_dev *bdev)
{
sector_t md_size_sect = 0;
- switch (bdev->dc.meta_dev_idx) {
+ int meta_dev_idx;
+
+ rcu_read_lock();
+ meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx;
+
+ switch (meta_dev_idx) {
default:
/* v07 style fixed size indexed meta data */
bdev->md.md_size_sect = MD_RESERVED_SECT;
@@ -713,6 +719,7 @@
bdev->md.bm_offset = -md_size_sect + MD_AL_OFFSET;
break;
}
+ rcu_read_unlock();
}
/* input size is expected to be in KB */
@@ -803,7 +810,9 @@
/* TODO: should only be some assert here, not (re)init... */
drbd_md_set_sector_offsets(mdev, mdev->ldev);
- u_size = mdev->ldev->dc.disk_size;
+ rcu_read_lock();
+ u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
+ rcu_read_unlock();
size = drbd_new_dev_size(mdev, mdev->ldev, u_size, flags & DDSF_FORCED);
if (drbd_get_capacity(mdev->this_bdev) != size ||
@@ -979,7 +988,9 @@
struct request_queue * const b = mdev->ldev->backing_bdev->bd_disk->queue;
max_hw_sectors = min(queue_max_hw_sectors(b), max_bio_size >> 9);
- max_segments = mdev->ldev->dc.max_bio_bvecs;
+ rcu_read_lock();
+ max_segments = rcu_dereference(mdev->ldev->disk_conf)->max_bio_bvecs;
+ rcu_read_unlock();
put_ldev(mdev);
}
@@ -1095,7 +1106,7 @@
{
enum drbd_ret_code retcode;
struct drbd_conf *mdev;
- struct disk_conf *new_disk_conf;
+ struct disk_conf *new_disk_conf, *old_disk_conf;
int err, fifo_size;
int *rs_plan_s = NULL;
@@ -1114,19 +1125,15 @@
goto out;
}
-/* FIXME freeze IO, cluster wide.
- *
- * We should make sure no-one uses
- * some half-updated struct when we
- * assign it later. */
-
- new_disk_conf = kmalloc(sizeof(*new_disk_conf), GFP_KERNEL);
+ new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
if (!new_disk_conf) {
retcode = ERR_NOMEM;
goto fail;
}
- memcpy(new_disk_conf, &mdev->ldev->dc, sizeof(*new_disk_conf));
+ mutex_lock(&mdev->tconn->conf_update);
+ old_disk_conf = mdev->ldev->disk_conf;
+ *new_disk_conf = *old_disk_conf;
if (should_set_defaults(info))
set_disk_conf_defaults(new_disk_conf);
@@ -1151,7 +1158,7 @@
if (!rs_plan_s) {
dev_err(DEV, "kmalloc of fifo_buffer failed");
retcode = ERR_NOMEM;
- goto fail;
+ goto fail_unlock;
}
}
@@ -1171,31 +1178,37 @@
if (err) {
retcode = ERR_NOMEM;
- goto fail;
+ goto fail_unlock;
}
- /* FIXME
- * To avoid someone looking at a half-updated struct, we probably
- * should have a rw-semaphor on net_conf and disk_conf.
- */
write_lock_irq(&global_state_lock);
retcode = drbd_sync_after_valid(mdev, new_disk_conf->resync_after);
if (retcode == NO_ERROR) {
- mdev->ldev->dc = *new_disk_conf;
+ rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
drbd_sync_after_changed(mdev);
}
write_unlock_irq(&global_state_lock);
- drbd_md_sync(mdev);
+ if (retcode != NO_ERROR)
+ goto fail_unlock;
+ drbd_md_sync(mdev);
if (mdev->state.conn >= C_CONNECTED)
drbd_send_sync_param(mdev);
+ mutex_unlock(&mdev->tconn->conf_update);
+ synchronize_rcu();
+ kfree(old_disk_conf);
+ goto success;
+
+fail_unlock:
+ mutex_unlock(&mdev->tconn->conf_update);
fail:
- put_ldev(mdev);
kfree(new_disk_conf);
kfree(rs_plan_s);
+success:
+ put_ldev(mdev);
out:
drbd_adm_finish(info, retcode);
return 0;
@@ -1210,6 +1223,7 @@
sector_t max_possible_sectors;
sector_t min_md_device_sectors;
struct drbd_backing_dev *nbc = NULL; /* new_backing_conf */
+ struct disk_conf *new_disk_conf = NULL;
struct block_device *bdev;
struct lru_cache *resync_lru = NULL;
union drbd_state ns, os;
@@ -1243,17 +1257,22 @@
retcode = ERR_NOMEM;
goto fail;
}
+ new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);
+ if (!new_disk_conf) {
+ retcode = ERR_NOMEM;
+ goto fail;
+ }
+ nbc->disk_conf = new_disk_conf;
- set_disk_conf_defaults(&nbc->dc);
-
- err = disk_conf_from_attrs(&nbc->dc, info);
+ set_disk_conf_defaults(new_disk_conf);
+ err = disk_conf_from_attrs(new_disk_conf, info);
if (err) {
retcode = ERR_MANDATORY_TAG;
drbd_msg_put_info(from_attrs_err_to_txt(err));
goto fail;
}
- if (nbc->dc.meta_dev_idx < DRBD_MD_INDEX_FLEX_INT) {
+ if (new_disk_conf->meta_dev_idx < DRBD_MD_INDEX_FLEX_INT) {
retcode = ERR_MD_IDX_INVALID;
goto fail;
}
@@ -1261,7 +1280,7 @@
rcu_read_lock();
nc = rcu_dereference(mdev->tconn->net_conf);
if (nc) {
- if (nbc->dc.fencing == FP_STONITH && nc->wire_protocol == DRBD_PROT_A) {
+ if (new_disk_conf->fencing == FP_STONITH && nc->wire_protocol == DRBD_PROT_A) {
rcu_read_unlock();
retcode = ERR_STONITH_AND_PROT_A;
goto fail;
@@ -1269,10 +1288,10 @@
}
rcu_read_unlock();
- bdev = blkdev_get_by_path(nbc->dc.backing_dev,
+ bdev = blkdev_get_by_path(new_disk_conf->backing_dev,
FMODE_READ | FMODE_WRITE | FMODE_EXCL, mdev);
if (IS_ERR(bdev)) {
- dev_err(DEV, "open(\"%s\") failed with %ld\n", nbc->dc.backing_dev,
+ dev_err(DEV, "open(\"%s\") failed with %ld\n", new_disk_conf->backing_dev,
PTR_ERR(bdev));
retcode = ERR_OPEN_DISK;
goto fail;
@@ -1287,12 +1306,12 @@
* should check it for you already; but if you don't, or
* someone fooled it, we need to double check here)
*/
- bdev = blkdev_get_by_path(nbc->dc.meta_dev,
+ bdev = blkdev_get_by_path(new_disk_conf->meta_dev,
FMODE_READ | FMODE_WRITE | FMODE_EXCL,
- (nbc->dc.meta_dev_idx < 0) ?
+ (new_disk_conf->meta_dev_idx < 0) ?
(void *)mdev : (void *)drbd_m_holder);
if (IS_ERR(bdev)) {
- dev_err(DEV, "open(\"%s\") failed with %ld\n", nbc->dc.meta_dev,
+ dev_err(DEV, "open(\"%s\") failed with %ld\n", new_disk_conf->meta_dev,
PTR_ERR(bdev));
retcode = ERR_OPEN_MD_DISK;
goto fail;
@@ -1300,8 +1319,8 @@
nbc->md_bdev = bdev;
if ((nbc->backing_bdev == nbc->md_bdev) !=
- (nbc->dc.meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
- nbc->dc.meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
+ (new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_INTERNAL ||
+ new_disk_conf->meta_dev_idx == DRBD_MD_INDEX_FLEX_INT)) {
retcode = ERR_MD_IDX_INVALID;
goto fail;
}
@@ -1317,21 +1336,21 @@
/* RT - for drbd_get_max_capacity() DRBD_MD_INDEX_FLEX_INT */
drbd_md_set_sector_offsets(mdev, nbc);
- if (drbd_get_max_capacity(nbc) < nbc->dc.disk_size) {
+ if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) {
dev_err(DEV, "max capacity %llu smaller than disk size %llu\n",
(unsigned long long) drbd_get_max_capacity(nbc),
- (unsigned long long) nbc->dc.disk_size);
+ (unsigned long long) new_disk_conf->disk_size);
retcode = ERR_DISK_TO_SMALL;
goto fail;
}
- if (nbc->dc.meta_dev_idx < 0) {
+ if (new_disk_conf->meta_dev_idx < 0) {
max_possible_sectors = DRBD_MAX_SECTORS_FLEX;
/* at least one MB, otherwise it does not make sense */
min_md_device_sectors = (2<<10);
} else {
max_possible_sectors = DRBD_MAX_SECTORS;
- min_md_device_sectors = MD_RESERVED_SECT * (nbc->dc.meta_dev_idx + 1);
+ min_md_device_sectors = MD_RESERVED_SECT * (new_disk_conf->meta_dev_idx + 1);
}
if (drbd_get_capacity(nbc->md_bdev) < min_md_device_sectors) {
@@ -1356,7 +1375,7 @@
dev_warn(DEV, "==> truncating very big lower level device "
"to currently maximum possible %llu sectors <==\n",
(unsigned long long) max_possible_sectors);
- if (nbc->dc.meta_dev_idx >= 0)
+ if (new_disk_conf->meta_dev_idx >= 0)
dev_warn(DEV, "==>> using internal or flexible "
"meta data may help <<==\n");
}
@@ -1399,14 +1418,14 @@
}
/* Since we are diskless, fix the activity log first... */
- if (drbd_check_al_size(mdev, &nbc->dc)) {
+ if (drbd_check_al_size(mdev, new_disk_conf)) {
retcode = ERR_NOMEM;
goto force_diskless_dec;
}
/* Prevent shrinking of consistent devices ! */
if (drbd_md_test_flag(nbc, MDF_CONSISTENT) &&
- drbd_new_dev_size(mdev, nbc, nbc->dc.disk_size, 0) < nbc->md.la_size_sect) {
+ drbd_new_dev_size(mdev, nbc, nbc->disk_conf->disk_size, 0) < nbc->md.la_size_sect) {
dev_warn(DEV, "refusing to truncate a consistent device\n");
retcode = ERR_DISK_TO_SMALL;
goto force_diskless_dec;
@@ -1419,11 +1438,13 @@
/* Reset the "barriers don't work" bits here, then force meta data to
* be written, to ensure we determine if barriers are supported. */
- if (nbc->dc.no_md_flush)
+ if (new_disk_conf->no_md_flush)
set_bit(MD_NO_FUA, &mdev->flags);
else
clear_bit(MD_NO_FUA, &mdev->flags);
+ /* FIXME Missing stuff: rs_plan_s, clip al range */
+
/* Point of no return reached.
* Devices and memory are no longer released by error cleanup below.
* now mdev takes over responsibility, and the state engine should
@@ -1433,6 +1454,7 @@
mdev->resync = resync_lru;
nbc = NULL;
resync_lru = NULL;
+ new_disk_conf = NULL;
mdev->write_ordering = WO_bdev_flush;
drbd_bump_write_ordering(mdev, WO_bdev_flush);
@@ -1530,9 +1552,11 @@
if (drbd_md_test_flag(mdev->ldev, MDF_PEER_OUT_DATED))
ns.pdsk = D_OUTDATED;
- if ( ns.disk == D_CONSISTENT &&
- (ns.pdsk == D_OUTDATED || mdev->ldev->dc.fencing == FP_DONT_CARE))
+ rcu_read_lock();
+ if (ns.disk == D_CONSISTENT &&
+ (ns.pdsk == D_OUTDATED || rcu_dereference(mdev->ldev->disk_conf)->fencing == FP_DONT_CARE))
ns.disk = D_UP_TO_DATE;
+ rcu_read_unlock();
/* All tests on MDF_PRIMARY_IND, MDF_CONNECTED_IND,
MDF_CONSISTENT and MDF_WAS_UP_TO_DATE must happen before
@@ -1589,6 +1613,7 @@
FMODE_READ | FMODE_WRITE | FMODE_EXCL);
kfree(nbc);
}
+ kfree(new_disk_conf);
lc_destroy(resync_lru);
finish:
@@ -1691,7 +1716,7 @@
idr_for_each_entry(&tconn->volumes, mdev, i) {
if (get_ldev(mdev)) {
- enum drbd_fencing_p fp = mdev->ldev->dc.fencing;
+ enum drbd_fencing_p fp = rcu_dereference(mdev->ldev->disk_conf)->fencing;
put_ldev(mdev);
if (new_conf->wire_protocol == DRBD_PROT_A && fp == FP_STONITH)
return ERR_STONITH_AND_PROT_A;
@@ -2159,11 +2184,13 @@
int drbd_adm_resize(struct sk_buff *skb, struct genl_info *info)
{
+ struct disk_conf *old_disk_conf, *new_disk_conf = NULL;
struct resize_parms rs;
struct drbd_conf *mdev;
enum drbd_ret_code retcode;
enum determine_dev_size dd;
enum dds_flags ddsf;
+ sector_t u_size;
int err;
retcode = drbd_adm_prepare(skb, info, DRBD_ADM_NEED_MINOR);
@@ -2204,10 +2231,31 @@
goto fail;
}
+ rcu_read_lock();
+ u_size = rcu_dereference(mdev->ldev->disk_conf)->disk_size;
+ rcu_read_unlock();
+ if (u_size != (sector_t)rs.resize_size) {
+ new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
+ if (!new_disk_conf) {
+ retcode = ERR_NOMEM;
+ goto fail;
+ }
+ }
+
if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev))
mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
- mdev->ldev->dc.disk_size = (sector_t)rs.resize_size;
+ if (new_disk_conf) {
+ mutex_lock(&mdev->tconn->conf_update);
+ old_disk_conf = mdev->ldev->disk_conf;
+ *new_disk_conf = *old_disk_conf;
+ new_disk_conf->disk_size = (sector_t)rs.resize_size;
+ rcu_assign_pointer(mdev->ldev->disk_conf, new_disk_conf);
+ mutex_unlock(&mdev->tconn->conf_update);
+ synchronize_rcu();
+ kfree(old_disk_conf);
+ }
+
ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
dd = drbd_determine_dev_size(mdev, ddsf);
drbd_md_sync(mdev);
@@ -2501,11 +2549,11 @@
if (res_opts_to_skb(skb, &mdev->tconn->res_opts, exclude_sensitive))
goto nla_put_failure;
+ rcu_read_lock();
if (got_ldev)
- if (disk_conf_to_skb(skb, &mdev->ldev->dc, exclude_sensitive))
+ if (disk_conf_to_skb(skb, rcu_dereference(mdev->ldev->disk_conf), exclude_sensitive))
goto nla_put_failure;
- rcu_read_lock();
nc = rcu_dereference(mdev->tconn->net_conf);
if (nc)
err = net_conf_to_skb(skb, nc, exclude_sensitive);
