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-rw-r--r--libbcache/migrate.c395
1 files changed, 0 insertions, 395 deletions
diff --git a/libbcache/migrate.c b/libbcache/migrate.c
deleted file mode 100644
index 9ef9685e..00000000
--- a/libbcache/migrate.c
+++ /dev/null
@@ -1,395 +0,0 @@
-/*
- * Code for moving data off a device.
- */
-
-#include "bcache.h"
-#include "btree_update.h"
-#include "buckets.h"
-#include "extents.h"
-#include "io.h"
-#include "journal.h"
-#include "keylist.h"
-#include "migrate.h"
-#include "move.h"
-#include "super-io.h"
-
-static int issue_migration_move(struct bch_dev *ca,
- struct moving_context *ctxt,
- struct bkey_s_c k)
-{
- struct bch_fs *c = ca->fs;
- struct disk_reservation res;
- const struct bch_extent_ptr *ptr;
- int ret;
-
- if (bch_disk_reservation_get(c, &res, k.k->size, 0))
- return -ENOSPC;
-
- extent_for_each_ptr(bkey_s_c_to_extent(k), ptr)
- if (ptr->dev == ca->dev_idx)
- goto found;
-
- BUG();
-found:
- /* XXX: we need to be doing something with the disk reservation */
-
- ret = bch_data_move(c, ctxt, &c->migration_write_point, k, ptr);
- if (ret)
- bch_disk_reservation_put(c, &res);
- return ret;
-}
-
-#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 bch_move_data_off_device(struct bch_dev *ca)
-{
- struct moving_context ctxt;
- struct bch_fs *c = ca->fs;
- struct bch_sb_field_members *mi;
- unsigned pass = 0;
- u64 seen_key_count;
- int ret = 0;
-
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
-
- if (!ca->mi.has_data)
- return 0;
-
- bch_move_ctxt_init(&ctxt, NULL, SECTORS_IN_FLIGHT_PER_DEVICE);
- ctxt.avoid = ca;
-
- /*
- * 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.
- */
-
- 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);
-
- bch_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN);
-
- while (!bch_move_ctxt_wait(&ctxt) &&
- (k = bch_btree_iter_peek(&iter)).k &&
- !(ret = btree_iter_err(k))) {
- if (!bkey_extent_is_data(k.k) ||
- !bch_extent_has_device(bkey_s_c_to_extent(k),
- ca->dev_idx))
- goto next;
-
- ret = issue_migration_move(ca, &ctxt, k);
- if (ret == -ENOMEM) {
- bch_btree_iter_unlock(&iter);
-
- /*
- * memory allocation failure, wait for some IO
- * to finish
- */
- bch_move_ctxt_wait_for_io(&ctxt);
- continue;
- }
- if (ret == -ENOSPC)
- break;
- BUG_ON(ret);
-
- seen_key_count++;
-next:
- bch_btree_iter_advance_pos(&iter);
- bch_btree_iter_cond_resched(&iter);
-
- }
- bch_btree_iter_unlock(&iter);
- bch_move_ctxt_exit(&ctxt);
-
- if (ret)
- return ret;
- } 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);
- return -1;
- }
-
- mutex_lock(&c->sb_lock);
- mi = bch_sb_get_members(c->disk_sb);
- SET_BCH_MEMBER_HAS_DATA(&mi->members[ca->dev_idx], false);
-
- bch_write_super(c);
- mutex_unlock(&c->sb_lock);
-
- return 0;
-}
-
-/*
- * This walks the btree, and for any node on the relevant device it moves the
- * node elsewhere.
- */
-static int bch_move_btree_off(struct bch_dev *ca, enum btree_id id)
-{
- struct bch_fs *c = ca->fs;
- struct btree_iter iter;
- struct closure cl;
- struct btree *b;
- int ret;
-
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
-
- closure_init_stack(&cl);
-
- for_each_btree_node(&iter, c, id, POS_MIN, 0, b) {
- struct bkey_s_c_extent e = bkey_i_to_s_c_extent(&b->key);
-retry:
- if (!bch_extent_has_device(e, ca->dev_idx))
- continue;
-
- ret = bch_btree_node_rewrite(&iter, b, &cl);
- if (ret == -EINTR || ret == -ENOSPC) {
- /*
- * Drop locks to upgrade locks or wait on
- * reserve: after retaking, recheck in case we
- * raced.
- */
- bch_btree_iter_unlock(&iter);
- closure_sync(&cl);
- b = bch_btree_iter_peek_node(&iter);
- goto retry;
- }
- if (ret) {
- bch_btree_iter_unlock(&iter);
- return ret;
- }
-
- bch_btree_iter_set_locks_want(&iter, 0);
- }
- ret = bch_btree_iter_unlock(&iter);
- if (ret)
- return ret; /* btree IO error */
-
- if (IS_ENABLED(CONFIG_BCACHE_DEBUG)) {
- for_each_btree_node(&iter, c, id, POS_MIN, 0, b) {
- struct bkey_s_c_extent e = bkey_i_to_s_c_extent(&b->key);
-
- BUG_ON(bch_extent_has_device(e, ca->dev_idx));
- }
- bch_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 bch_move_metadata_off_device(struct bch_dev *ca)
-{
- struct bch_fs *c = ca->fs;
- struct bch_sb_field_members *mi;
- unsigned i;
- int ret;
-
- BUG_ON(ca->mi.state == BCH_MEMBER_STATE_RW);
-
- if (!ca->mi.has_metadata)
- return 0;
-
- /* 1st, Move the btree nodes off the device */
-
- for (i = 0; i < BTREE_ID_NR; i++) {
- ret = bch_move_btree_off(ca, i);
- if (ret)
- return ret;
- }
-
- /* There are no prios/gens to move -- they are already in the device. */
-
- /* 2nd. Move the journal off the device */
-
- ret = bch_journal_move(ca);
- if (ret)
- return ret;
-
- mutex_lock(&c->sb_lock);
- mi = bch_sb_get_members(c->disk_sb);
- SET_BCH_MEMBER_HAS_METADATA(&mi->members[ca->dev_idx], false);
-
- bch_write_super(c);
- mutex_unlock(&c->sb_lock);
-
- return 0;
-}
-
-/*
- * Flagging data bad when forcibly removing a device after failing to
- * migrate the data off the device.
- */
-
-static int bch_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;
-
- 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)
- bch_extent_drop_ptr(e, ptr);
-
- /*
- * If the new extent no longer has any pointers, bch_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)
- */
- bch_extent_normalize(c, e.s);
-
- return bch_btree_insert_at(c, NULL, NULL, NULL,
- BTREE_INSERT_ATOMIC,
- BTREE_INSERT_ENTRY(iter, &tmp.key));
-}
-
-/*
- * 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 bch_flag_data_bad(struct bch_dev *ca)
-{
- int ret = 0;
- struct bkey_s_c k;
- struct bkey_s_c_extent e;
- struct btree_iter iter;
-
- bch_btree_iter_init(&iter, ca->fs, BTREE_ID_EXTENTS, POS_MIN);
-
- while ((k = bch_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 (!bch_extent_has_device(e, ca->dev_idx))
- goto advance;
-
- ret = bch_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:
- bch_btree_iter_advance_pos(&iter);
- }
-
- bch_btree_iter_unlock(&iter);
-
- return ret;
-}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-02 03:41:43 +0000