drbd: Allow online change of al-stripes and al-stripe-size
Allow to change the AL layout with an resize operation. For that
the reisze command gets two new fields: al_stripes and al_stripe_size.
In order to make the operation crash save:
1) Lock out all IO and MD-IO
2) Write the super block with MDF_PRIMARY_IND clear
3) write the bitmap to the new location (all zeros, since
we allow only while connected)
4) Initialize the new AL-area
5) Write the super block with the restored MDF_PRIMARY_IND.
6) Unfreeze all IO
Since the AL-layout has no influence on the protocol, this operation
needs to be beforemed on both sides of a resource (if intended).
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 45d1275..8cc1e64 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -827,12 +827,17 @@
* Returns 0 on success, negative return values indicate errors.
* You should call drbd_md_sync() after calling this function.
*/
-enum determine_dev_size drbd_determine_dev_size(struct drbd_conf *mdev, enum dds_flags flags) __must_hold(local)
+enum determine_dev_size
+drbd_determine_dev_size(struct drbd_conf *mdev, enum dds_flags flags, struct resize_parms *rs) __must_hold(local)
{
sector_t prev_first_sect, prev_size; /* previous meta location */
sector_t la_size_sect, u_size;
+ struct drbd_md *md = &mdev->ldev->md;
+ u32 prev_al_stripe_size_4k;
+ u32 prev_al_stripes;
sector_t size;
char ppb[10];
+ void *buffer;
int md_moved, la_size_changed;
enum determine_dev_size rv = DS_UNCHANGED;
@@ -847,6 +852,11 @@
* still lock the act_log to not trigger ASSERTs there.
*/
drbd_suspend_io(mdev);
+ buffer = drbd_md_get_buffer(mdev); /* Lock meta-data IO */
+ if (!buffer) {
+ drbd_resume_io(mdev);
+ return DS_ERROR;
+ }
/* no wait necessary anymore, actually we could assert that */
wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
@@ -855,7 +865,17 @@
prev_size = mdev->ldev->md.md_size_sect;
la_size_sect = mdev->ldev->md.la_size_sect;
- /* TODO: should only be some assert here, not (re)init... */
+ if (rs) {
+ /* rs is non NULL if we should change the AL layout only */
+
+ prev_al_stripes = md->al_stripes;
+ prev_al_stripe_size_4k = md->al_stripe_size_4k;
+
+ md->al_stripes = rs->al_stripes;
+ md->al_stripe_size_4k = rs->al_stripe_size / 4;
+ md->al_size_4k = (u64)rs->al_stripes * rs->al_stripe_size / 4;
+ }
+
drbd_md_set_sector_offsets(mdev, mdev->ldev);
rcu_read_lock();
@@ -863,6 +883,21 @@
rcu_read_unlock();
size = drbd_new_dev_size(mdev, mdev->ldev, u_size, flags & DDSF_FORCED);
+ if (size < la_size_sect) {
+ if (rs && u_size == 0) {
+ /* Remove "rs &&" later. This check should always be active, but
+ right now the receiver expects the permissive behavior */
+ dev_warn(DEV, "Implicit shrink not allowed. "
+ "Use --size=%llus for explicit shrink.\n",
+ (unsigned long long)size);
+ rv = DS_ERROR_SHRINK;
+ }
+ if (u_size > size)
+ rv = DS_ERROR_SPACE_MD;
+ if (rv != DS_UNCHANGED)
+ goto err_out;
+ }
+
if (drbd_get_capacity(mdev->this_bdev) != size ||
drbd_bm_capacity(mdev) != size) {
int err;
@@ -886,38 +921,57 @@
dev_info(DEV, "size = %s (%llu KB)\n", ppsize(ppb, size>>1),
(unsigned long long)size>>1);
}
- if (rv == DS_ERROR)
- goto out;
+ if (rv <= DS_ERROR)
+ goto err_out;
la_size_changed = (la_size_sect != mdev->ldev->md.la_size_sect);
md_moved = prev_first_sect != drbd_md_first_sector(mdev->ldev)
|| prev_size != mdev->ldev->md.md_size_sect;
- if (la_size_changed || md_moved) {
- int err;
+ if (la_size_changed || md_moved || rs) {
+ u32 prev_flags;
drbd_al_shrink(mdev); /* All extents inactive. */
+
+ prev_flags = md->flags;
+ md->flags &= ~MDF_PRIMARY_IND;
+ drbd_md_write(mdev, buffer);
+
dev_info(DEV, "Writing the whole bitmap, %s\n",
la_size_changed && md_moved ? "size changed and md moved" :
la_size_changed ? "size changed" : "md moved");
/* next line implicitly does drbd_suspend_io()+drbd_resume_io() */
- err = drbd_bitmap_io(mdev, md_moved ? &drbd_bm_write_all : &drbd_bm_write,
- "size changed", BM_LOCKED_MASK);
- if (err) {
- rv = DS_ERROR;
- goto out;
- }
- drbd_md_mark_dirty(mdev);
+ drbd_bitmap_io(mdev, md_moved ? &drbd_bm_write_all : &drbd_bm_write,
+ "size changed", BM_LOCKED_MASK);
+ drbd_initialize_al(mdev, buffer);
+
+ md->flags = prev_flags;
+ drbd_md_write(mdev, buffer);
+
+ if (rs)
+ dev_info(DEV, "Changed AL layout to al-stripes = %d, al-stripe-size-kB = %d\n",
+ md->al_stripes, md->al_stripe_size_4k * 4);
}
if (size > la_size_sect)
rv = DS_GREW;
if (size < la_size_sect)
rv = DS_SHRUNK;
-out:
+
+ if (0) {
+ err_out:
+ if (rs) {
+ md->al_stripes = prev_al_stripes;
+ md->al_stripe_size_4k = prev_al_stripe_size_4k;
+ md->al_size_4k = (u64)prev_al_stripes * prev_al_stripe_size_4k;
+
+ drbd_md_set_sector_offsets(mdev, mdev->ldev);
+ }
+ }
lc_unlock(mdev->act_log);
wake_up(&mdev->al_wait);
+ drbd_md_put_buffer(mdev);
drbd_resume_io(mdev);
return rv;
@@ -1618,8 +1672,8 @@
!drbd_md_test_flag(mdev->ldev, MDF_CONNECTED_IND))
set_bit(USE_DEGR_WFC_T, &mdev->flags);
- dd = drbd_determine_dev_size(mdev, 0);
- if (dd == DS_ERROR) {
+ dd = drbd_determine_dev_size(mdev, 0, NULL);
+ if (dd <= DS_ERROR) {
retcode = ERR_NOMEM_BITMAP;
goto force_diskless_dec;
} else if (dd == DS_GREW)
@@ -2316,6 +2370,7 @@
struct drbd_conf *mdev;
enum drbd_ret_code retcode;
enum determine_dev_size dd;
+ bool change_al_layout = false;
enum dds_flags ddsf;
sector_t u_size;
int err;
@@ -2326,31 +2381,33 @@
if (retcode != NO_ERROR)
goto fail;
+ mdev = adm_ctx.mdev;
+ if (!get_ldev(mdev)) {
+ retcode = ERR_NO_DISK;
+ goto fail;
+ }
+
memset(&rs, 0, sizeof(struct resize_parms));
+ rs.al_stripes = mdev->ldev->md.al_stripes;
+ rs.al_stripe_size = mdev->ldev->md.al_stripe_size_4k * 4;
if (info->attrs[DRBD_NLA_RESIZE_PARMS]) {
err = resize_parms_from_attrs(&rs, info);
if (err) {
retcode = ERR_MANDATORY_TAG;
drbd_msg_put_info(from_attrs_err_to_txt(err));
- goto fail;
+ goto fail_ldev;
}
}
- mdev = adm_ctx.mdev;
if (mdev->state.conn > C_CONNECTED) {
retcode = ERR_RESIZE_RESYNC;
- goto fail;
+ goto fail_ldev;
}
if (mdev->state.role == R_SECONDARY &&
mdev->state.peer == R_SECONDARY) {
retcode = ERR_NO_PRIMARY;
- goto fail;
- }
-
- if (!get_ldev(mdev)) {
- retcode = ERR_NO_DISK;
- goto fail;
+ goto fail_ldev;
}
if (rs.no_resync && mdev->tconn->agreed_pro_version < 93) {
@@ -2369,6 +2426,28 @@
}
}
+ if (mdev->ldev->md.al_stripes != rs.al_stripes ||
+ mdev->ldev->md.al_stripe_size_4k != rs.al_stripe_size / 4) {
+ u32 al_size_k = rs.al_stripes * rs.al_stripe_size;
+
+ if (al_size_k > (16 * 1024 * 1024)) {
+ retcode = ERR_MD_LAYOUT_TOO_BIG;
+ goto fail_ldev;
+ }
+
+ if (al_size_k < MD_32kB_SECT/2) {
+ retcode = ERR_MD_LAYOUT_TOO_SMALL;
+ goto fail_ldev;
+ }
+
+ if (mdev->state.conn != C_CONNECTED) {
+ retcode = ERR_MD_LAYOUT_CONNECTED;
+ goto fail_ldev;
+ }
+
+ change_al_layout = true;
+ }
+
if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev))
mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
@@ -2384,12 +2463,18 @@
}
ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
- dd = drbd_determine_dev_size(mdev, ddsf);
+ dd = drbd_determine_dev_size(mdev, ddsf, change_al_layout ? &rs : NULL);
drbd_md_sync(mdev);
put_ldev(mdev);
if (dd == DS_ERROR) {
retcode = ERR_NOMEM_BITMAP;
goto fail;
+ } else if (dd == DS_ERROR_SPACE_MD) {
+ retcode = ERR_MD_LAYOUT_NO_FIT;
+ goto fail;
+ } else if (dd == DS_ERROR_SHRINK) {
+ retcode = ERR_IMPLICIT_SHRINK;
+ goto fail;
}
if (mdev->state.conn == C_CONNECTED) {
