+// SPDX-License-Identifier: GPL-2.0
/*
* Code for moving data off a device.
*/
#include "bcachefs.h"
+#include "bkey_buf.h"
#include "btree_update.h"
+#include "btree_update_interior.h"
#include "buckets.h"
+#include "errcode.h"
#include "extents.h"
-#include "io.h"
+#include "io_write.h"
#include "journal.h"
#include "keylist.h"
#include "migrate.h"
#include "move.h"
+#include "replicas.h"
#include "super-io.h"
-static int issue_migration_move(struct bch_dev *ca,
- struct moving_context *ctxt,
- struct bkey_s_c k)
+static int drop_dev_ptrs(struct bch_fs *c, struct bkey_s k,
+ unsigned dev_idx, int flags, bool metadata)
{
- struct bch_fs *c = ca->fs;
- struct disk_reservation res;
- const struct bch_extent_ptr *ptr;
- int ret;
-
- if (bch2_disk_reservation_get(c, &res, k.k->size, 0))
- return -ENOSPC;
+ unsigned replicas = metadata ? c->opts.metadata_replicas : c->opts.data_replicas;
+ unsigned lost = metadata ? BCH_FORCE_IF_METADATA_LOST : BCH_FORCE_IF_DATA_LOST;
+ unsigned degraded = metadata ? BCH_FORCE_IF_METADATA_DEGRADED : BCH_FORCE_IF_DATA_DEGRADED;
+ unsigned nr_good;
- extent_for_each_ptr(bkey_s_c_to_extent(k), ptr)
- if (ptr->dev == ca->dev_idx)
- goto found;
+ bch2_bkey_drop_device(k, dev_idx);
- BUG();
-found:
- /* XXX: we need to be doing something with the disk reservation */
+ nr_good = bch2_bkey_durability(c, k.s_c);
+ if ((!nr_good && !(flags & lost)) ||
+ (nr_good < replicas && !(flags & degraded)))
+ return -BCH_ERR_remove_would_lose_data;
- ret = bch2_data_move(c, ctxt, &c->migration_write_point, k, ptr);
- if (ret)
- bch2_disk_reservation_put(c, &res);
- return ret;
+ return 0;
}
-#define MAX_DATA_OFF_ITER 10
-
-/*
- * This moves only the data off, leaving the meta-data (if any) in place.
- * It walks the key space, and for any key with a valid pointer to the
- * relevant device, it copies it elsewhere, updating the key to point to
- * the copy.
- * The meta-data is moved off by bch_move_meta_data_off_device.
- *
- * Note: If the number of data replicas desired is > 1, ideally, any
- * new copies would not be made in the same device that already have a
- * copy (if there are enough devices).
- * This is _not_ currently implemented. The multiple replicas can
- * land in the same device even if there are others available.
- */
-
-int bch2_move_data_off_device(struct bch_dev *ca)
+static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
+ struct btree_iter *iter,
+ struct bkey_s_c k,
+ unsigned dev_idx,
+ int flags)
{
- struct moving_context ctxt;
- struct bch_fs *c = ca->fs;
- unsigned pass = 0;
- u64 seen_key_count;
- int ret = 0;
-
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
+ struct bch_fs *c = trans->c;
+ struct bkey_i *n;
+ int ret;
- if (!(bch2_dev_has_data(c, ca) & (1 << BCH_DATA_USER)))
+ if (!bch2_bkey_has_device_c(k, dev_idx))
return 0;
- mutex_lock(&c->replicas_gc_lock);
- bch2_replicas_gc_start(c, 1 << BCH_DATA_USER);
+ n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+ ret = PTR_ERR_OR_ZERO(n);
+ if (ret)
+ return ret;
- bch2_move_ctxt_init(&ctxt, NULL, SECTORS_IN_FLIGHT_PER_DEVICE);
- __set_bit(ca->dev_idx, ctxt.avoid.d);
+ ret = drop_dev_ptrs(c, bkey_i_to_s(n), dev_idx, flags, false);
+ if (ret)
+ return ret;
/*
- * In theory, only one pass should be necessary as we've
- * quiesced all writes before calling this.
- *
- * However, in practice, more than one pass may be necessary:
- * - Some move fails due to an error. We can can find this out
- * from the moving_context.
- * - Some key swap failed because some of the pointers in the
- * key in the tree changed due to caching behavior, btree gc
- * pruning stale pointers, or tiering (if the device being
- * removed is in tier 0). A smarter bkey_cmpxchg would
- * handle these cases.
- *
- * Thus this scans the tree one more time than strictly necessary,
- * but that can be viewed as a verification pass.
+ * If the new extent no longer has any pointers, bch2_extent_normalize()
+ * will do the appropriate thing with it (turning it into a
+ * KEY_TYPE_error key, or just a discard if it was a cached extent)
*/
+ bch2_extent_normalize(c, bkey_i_to_s(n));
- do {
- struct btree_iter iter;
- struct bkey_s_c k;
-
- seen_key_count = 0;
- atomic_set(&ctxt.error_count, 0);
- atomic_set(&ctxt.error_flags, 0);
-
- bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN,
- BTREE_ITER_PREFETCH);
-
- while (!bch2_move_ctxt_wait(&ctxt) &&
- (k = bch2_btree_iter_peek(&iter)).k &&
- !(ret = btree_iter_err(k))) {
- if (!bkey_extent_is_data(k.k) ||
- !bch2_extent_has_device(bkey_s_c_to_extent(k),
- ca->dev_idx))
- goto next;
-
- ret = issue_migration_move(ca, &ctxt, k);
- if (ret == -ENOMEM) {
- bch2_btree_iter_unlock(&iter);
+ /*
+ * Since we're not inserting through an extent iterator
+ * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
+ * we aren't using the extent overwrite path to delete, we're
+ * just using the normal key deletion path:
+ */
+ if (bkey_deleted(&n->k))
+ n->k.size = 0;
+ return 0;
+}
- /*
- * memory allocation failure, wait for some IO
- * to finish
- */
- bch2_move_ctxt_wait_for_io(&ctxt);
- continue;
- }
- if (ret == -ENOSPC)
- break;
- BUG_ON(ret);
+static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
+{
+ struct btree_trans *trans = bch2_trans_get(c);
+ enum btree_id id;
+ int ret = 0;
- seen_key_count++;
+ for (id = 0; id < BTREE_ID_NR; id++) {
+ if (!btree_type_has_ptrs(id))
continue;
-next:
- if (bkey_extent_is_data(k.k)) {
- ret = bch2_check_mark_super(c, bkey_s_c_to_extent(k),
- BCH_DATA_USER);
- if (ret)
- break;
- }
- bch2_btree_iter_advance_pos(&iter);
- bch2_btree_iter_cond_resched(&iter);
-
- }
- bch2_btree_iter_unlock(&iter);
- bch2_move_ctxt_exit(&ctxt);
+ ret = for_each_btree_key_commit(trans, iter, id, POS_MIN,
+ BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+ NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
+ bch2_dev_usrdata_drop_key(trans, &iter, k, dev_idx, flags));
if (ret)
- goto err;
- } while (seen_key_count && pass++ < MAX_DATA_OFF_ITER);
-
- if (seen_key_count) {
- pr_err("Unable to migrate all data in %d iterations.",
- MAX_DATA_OFF_ITER);
- ret = -1;
- goto err;
+ break;
}
-err:
- bch2_replicas_gc_end(c, ret);
- mutex_unlock(&c->replicas_gc_lock);
+ bch2_trans_put(trans);
+
return ret;
}
-/*
- * This walks the btree, and for any node on the relevant device it moves the
- * node elsewhere.
- */
-static int bch2_move_btree_off(struct bch_fs *c, struct bch_dev *ca,
- enum btree_id id)
+static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
{
+ struct btree_trans *trans;
struct btree_iter iter;
struct closure cl;
struct btree *b;
+ struct bkey_buf k;
+ unsigned id;
int ret;
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
+ /* don't handle this yet: */
+ if (flags & BCH_FORCE_IF_METADATA_LOST)
+ return -BCH_ERR_remove_with_metadata_missing_unimplemented;
+ trans = bch2_trans_get(c);
+ bch2_bkey_buf_init(&k);
closure_init_stack(&cl);
- for_each_btree_node(&iter, c, id, POS_MIN, BTREE_ITER_PREFETCH, b) {
- struct bkey_s_c_extent e = bkey_i_to_s_c_extent(&b->key);
-
- if (!bch2_extent_has_device(e, ca->dev_idx))
- continue;
+ for (id = 0; id < BTREE_ID_NR; id++) {
+ bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
+ BTREE_ITER_PREFETCH);
+retry:
+ ret = 0;
+ while (bch2_trans_begin(trans),
+ (b = bch2_btree_iter_peek_node(&iter)) &&
+ !(ret = PTR_ERR_OR_ZERO(b))) {
+ if (!bch2_bkey_has_device_c(bkey_i_to_s_c(&b->key), dev_idx))
+ goto next;
- ret = bch2_btree_node_rewrite(c, &iter, b->data->keys.seq, 0);
- if (ret) {
- bch2_btree_iter_unlock(&iter);
- return ret;
- }
+ bch2_bkey_buf_copy(&k, c, &b->key);
- bch2_btree_iter_set_locks_want(&iter, 0);
- }
- ret = bch2_btree_iter_unlock(&iter);
- if (ret)
- return ret; /* btree IO error */
+ ret = drop_dev_ptrs(c, bkey_i_to_s(k.k),
+ dev_idx, flags, true);
+ if (ret)
+ break;
- if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
- for_each_btree_node(&iter, c, id, POS_MIN, BTREE_ITER_PREFETCH, b) {
- struct bkey_s_c_extent e = bkey_i_to_s_c_extent(&b->key);
+ ret = bch2_btree_node_update_key(trans, &iter, b, k.k, 0, false);
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
+ ret = 0;
+ continue;
+ }
- BUG_ON(bch2_extent_has_device(e, ca->dev_idx));
+ bch_err_msg(c, ret, "updating btree node key");
+ if (ret)
+ break;
+next:
+ bch2_btree_iter_next_node(&iter);
}
- bch2_btree_iter_unlock(&iter);
- }
-
- return 0;
-}
-
-/*
- * This moves only the meta-data off, leaving the data (if any) in place.
- * The data is moved off by bch_move_data_off_device, if desired, and
- * called first.
- *
- * Before calling this, allocation of buckets to the device must have
- * been disabled, as else we'll continue to write meta-data to the device
- * when new buckets are picked for meta-data writes.
- * In addition, the copying gc and allocator threads for the device
- * must have been stopped. The allocator thread is the only thread
- * that writes prio/gen information.
- *
- * Meta-data consists of:
- * - Btree nodes
- * - Prio/gen information
- * - Journal entries
- * - Superblock
- *
- * This has to move the btree nodes and the journal only:
- * - prio/gen information is not written once the allocator thread is stopped.
- * also, as the prio/gen information is per-device it is not moved.
- * - the superblock will be written by the caller once after everything
- * is stopped.
- *
- * Note that currently there is no way to stop btree node and journal
- * meta-data writes to a device without moving the meta-data because
- * once a bucket is open for a btree node, unless a replacement btree
- * node is allocated (and the tree updated), the bucket will continue
- * to be written with updates. Similarly for the journal (it gets
- * written until filled).
- *
- * This routine leaves the data (if any) in place. Whether the data
- * should be moved off is a decision independent of whether the meta
- * data should be moved off and stopped:
- *
- * - For device removal, both data and meta-data are moved off, in
- * that order.
- *
- * - However, for turning a device read-only without removing it, only
- * meta-data is moved off since that's the only way to prevent it
- * from being written. Data is left in the device, but no new data
- * is written.
- */
-
-int bch2_move_metadata_off_device(struct bch_dev *ca)
-{
- struct bch_fs *c = ca->fs;
- unsigned i;
- int ret = 0;
-
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
-
- if (!(bch2_dev_has_data(c, ca) &
- ((1 << BCH_DATA_JOURNAL)|
- (1 << BCH_DATA_BTREE))))
- return 0;
-
- mutex_lock(&c->replicas_gc_lock);
- bch2_replicas_gc_start(c,
- (1 << BCH_DATA_JOURNAL)|
- (1 << BCH_DATA_BTREE));
+ if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
+ goto retry;
- /* 1st, Move the btree nodes off the device */
+ bch2_trans_iter_exit(trans, &iter);
- for (i = 0; i < BTREE_ID_NR; i++) {
- ret = bch2_move_btree_off(c, ca, i);
if (ret)
goto err;
}
- /* There are no prios/gens to move -- they are already in the device. */
-
- /* 2nd. Move the journal off the device */
-
- ret = bch2_journal_move(ca);
- if (ret)
- goto err;
-
+ bch2_btree_interior_updates_flush(c);
+ ret = 0;
err:
- bch2_replicas_gc_end(c, ret);
- mutex_unlock(&c->replicas_gc_lock);
- return ret;
-}
+ bch2_bkey_buf_exit(&k, c);
+ bch2_trans_put(trans);
-/*
- * Flagging data bad when forcibly removing a device after failing to
- * migrate the data off the device.
- */
-
-static int bch2_flag_key_bad(struct btree_iter *iter,
- struct bch_dev *ca,
- struct bkey_s_c_extent orig)
-{
- BKEY_PADDED(key) tmp;
- struct bkey_s_extent e;
- struct bch_extent_ptr *ptr;
- struct bch_fs *c = ca->fs;
+ BUG_ON(bch2_err_matches(ret, BCH_ERR_transaction_restart));
- bkey_reassemble(&tmp.key, orig.s_c);
- e = bkey_i_to_s_extent(&tmp.key);
-
- extent_for_each_ptr_backwards(e, ptr)
- if (ptr->dev == ca->dev_idx)
- bch2_extent_drop_ptr(e, ptr);
-
- /*
- * If the new extent no longer has any pointers, bch2_extent_normalize()
- * will do the appropriate thing with it (turning it into a
- * KEY_TYPE_ERROR key, or just a discard if it was a cached extent)
- */
- bch2_extent_normalize(c, e.s);
-
- return bch2_btree_insert_at(c, NULL, NULL, NULL,
- BTREE_INSERT_ATOMIC,
- BTREE_INSERT_ENTRY(iter, &tmp.key));
+ return ret;
}
-/*
- * This doesn't actually move any data -- it marks the keys as bad
- * if they contain a pointer to a device that is forcibly removed
- * and don't have other valid pointers. If there are valid pointers,
- * the necessary pointers to the removed device are replaced with
- * bad pointers instead.
- *
- * This is only called if bch_move_data_off_device above failed, meaning
- * that we've already tried to move the data MAX_DATA_OFF_ITER times and
- * are not likely to succeed if we try again.
- */
-int bch2_flag_data_bad(struct bch_dev *ca)
+int bch2_dev_data_drop(struct bch_fs *c, unsigned dev_idx, int flags)
{
- struct bch_fs *c = ca->fs;
- struct bkey_s_c k;
- struct bkey_s_c_extent e;
- struct btree_iter iter;
- int ret = 0;
-
- mutex_lock(&c->replicas_gc_lock);
- bch2_replicas_gc_start(c, 1 << BCH_DATA_USER);
-
- bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS,
- POS_MIN, BTREE_ITER_PREFETCH);
-
- while ((k = bch2_btree_iter_peek(&iter)).k &&
- !(ret = btree_iter_err(k))) {
- if (!bkey_extent_is_data(k.k))
- goto advance;
-
- e = bkey_s_c_to_extent(k);
- if (!bch2_extent_has_device(e, ca->dev_idx))
- goto advance;
-
- ret = bch2_flag_key_bad(&iter, ca, e);
-
- /*
- * don't want to leave ret == -EINTR, since if we raced and
- * something else overwrote the key we could spuriously return
- * -EINTR below:
- */
- if (ret == -EINTR)
- ret = 0;
- if (ret)
- break;
-
- /*
- * If the replica we're dropping was dirty and there is an
- * additional cached replica, the cached replica will now be
- * considered dirty - upon inserting the new version of the key,
- * the bucket accounting will be updated to reflect the fact
- * that the cached data is now dirty and everything works out as
- * if by magic without us having to do anything.
- *
- * The one thing we need to be concerned with here is there's a
- * race between when we drop any stale pointers from the key
- * we're about to insert, and when the key actually gets
- * inserted and the cached data is marked as dirty - we could
- * end up trying to insert a key with a pointer that should be
- * dirty, but points to stale data.
- *
- * If that happens the insert code just bails out and doesn't do
- * the insert - however, it doesn't return an error. Hence we
- * need to always recheck the current key before advancing to
- * the next:
- */
- continue;
-advance:
- if (bkey_extent_is_data(k.k)) {
- ret = bch2_check_mark_super(c, bkey_s_c_to_extent(k),
- BCH_DATA_USER);
- if (ret)
- break;
- }
- bch2_btree_iter_advance_pos(&iter);
- }
-
- bch2_btree_iter_unlock(&iter);
-
- bch2_replicas_gc_end(c, ret);
- mutex_unlock(&c->replicas_gc_lock);
-
- return ret;
+ return bch2_dev_usrdata_drop(c, dev_idx, flags) ?:
+ bch2_dev_metadata_drop(c, dev_idx, flags);
}
projects / bcachefs-tools-debian / blobdiff