]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/journal.c
Update bcachefs sources to c887148ebf99 thread_with_file: add f_ops.flush
[bcachefs-tools-debian] / libbcachefs / journal.c
index 80a612c0577f25d4228aabc3567d4e7aebe3de61..46dc25ad95e7534040c8d96858aa43028c39950b 100644 (file)
@@ -10,6 +10,7 @@
 #include "bkey_methods.h"
 #include "btree_gc.h"
 #include "btree_update.h"
+#include "btree_write_buffer.h"
 #include "buckets.h"
 #include "error.h"
 #include "journal.h"
@@ -46,6 +47,70 @@ static bool journal_entry_is_open(struct journal *j)
        return __journal_entry_is_open(j->reservations);
 }
 
+static void bch2_journal_buf_to_text(struct printbuf *out, struct journal *j, u64 seq)
+{
+       union journal_res_state s = READ_ONCE(j->reservations);
+       unsigned i = seq & JOURNAL_BUF_MASK;
+       struct journal_buf *buf = j->buf + i;
+
+       prt_str(out, "seq:");
+       prt_tab(out);
+       prt_printf(out, "%llu", seq);
+       prt_newline(out);
+       printbuf_indent_add(out, 2);
+
+       prt_str(out, "refcount:");
+       prt_tab(out);
+       prt_printf(out, "%u", journal_state_count(s, i));
+       prt_newline(out);
+
+       prt_str(out, "size:");
+       prt_tab(out);
+       prt_human_readable_u64(out, vstruct_bytes(buf->data));
+       prt_newline(out);
+
+       prt_str(out, "expires:");
+       prt_tab(out);
+       prt_printf(out, "%li jiffies", buf->expires - jiffies);
+       prt_newline(out);
+
+       prt_str(out, "flags:");
+       prt_tab(out);
+       if (buf->noflush)
+               prt_str(out, "noflush ");
+       if (buf->must_flush)
+               prt_str(out, "must_flush ");
+       if (buf->separate_flush)
+               prt_str(out, "separate_flush ");
+       if (buf->need_flush_to_write_buffer)
+               prt_str(out, "need_flush_to_write_buffer ");
+       if (buf->need_flush_to_write_buffer)
+               prt_str(out, "need_flush_to_write_buffer ");
+       if (buf->write_done)
+               prt_str(out, "write done ");
+       if (buf->write_started)
+               prt_str(out, "write started ");
+       if (buf->write_allocated)
+               prt_str(out, "write allocated ");
+       if (buf->write_done)
+               prt_str(out, "write done");
+       prt_newline(out);
+
+       printbuf_indent_sub(out, 2);
+}
+
+static void bch2_journal_bufs_to_text(struct printbuf *out, struct journal *j)
+{
+       if (!out->nr_tabstops)
+               printbuf_tabstop_push(out, 24);
+
+       for (u64 seq = journal_last_unwritten_seq(j);
+            seq <= journal_cur_seq(j);
+            seq++)
+               bch2_journal_buf_to_text(out, j, seq);
+       prt_printf(out, "last buf %s\n", journal_entry_is_open(j) ? "open" : "closed");
+}
+
 static inline struct journal_buf *
 journal_seq_to_buf(struct journal *j, u64 seq)
 {
@@ -63,6 +128,7 @@ journal_seq_to_buf(struct journal *j, u64 seq)
 static void journal_pin_list_init(struct journal_entry_pin_list *p, int count)
 {
        unsigned i;
+
        for (i = 0; i < ARRAY_SIZE(p->list); i++)
                INIT_LIST_HEAD(&p->list[i]);
        INIT_LIST_HEAD(&p->flushed);
@@ -131,13 +197,40 @@ journal_error_check_stuck(struct journal *j, int error, unsigned flags)
        return stuck;
 }
 
-/* journal entry close/open: */
+void bch2_journal_do_writes(struct journal *j)
+{
+       for (u64 seq = journal_last_unwritten_seq(j);
+            seq <= journal_cur_seq(j);
+            seq++) {
+               unsigned idx = seq & JOURNAL_BUF_MASK;
+               struct journal_buf *w = j->buf + idx;
+
+               if (w->write_started && !w->write_allocated)
+                       break;
+               if (w->write_started)
+                       continue;
+
+               if (!journal_state_count(j->reservations, idx)) {
+                       w->write_started = true;
+                       closure_call(&w->io, bch2_journal_write, j->wq, NULL);
+               }
 
-void __bch2_journal_buf_put(struct journal *j)
+               break;
+       }
+}
+
+/*
+ * Final processing when the last reference of a journal buffer has been
+ * dropped. Drop the pin list reference acquired at journal entry open and write
+ * the buffer, if requested.
+ */
+void bch2_journal_buf_put_final(struct journal *j, u64 seq)
 {
-       struct bch_fs *c = container_of(j, struct bch_fs, journal);
+       lockdep_assert_held(&j->lock);
 
-       closure_call(&j->io, bch2_journal_write, c->io_complete_wq, NULL);
+       if (__bch2_journal_pin_put(j, seq))
+               bch2_journal_reclaim_fast(j);
+       bch2_journal_do_writes(j);
 }
 
 /*
@@ -146,7 +239,7 @@ void __bch2_journal_buf_put(struct journal *j)
  * We don't close a journal_buf until the next journal_buf is finished writing,
  * and can be opened again - this also initializes the next journal_buf:
  */
-static void __journal_entry_close(struct journal *j, unsigned closed_val)
+static void __journal_entry_close(struct journal *j, unsigned closed_val, bool trace)
 {
        struct bch_fs *c = container_of(j, struct bch_fs, journal);
        struct journal_buf *buf = journal_cur_buf(j);
@@ -175,6 +268,18 @@ static void __journal_entry_close(struct journal *j, unsigned closed_val)
        /* Close out old buffer: */
        buf->data->u64s         = cpu_to_le32(old.cur_entry_offset);
 
+       if (trace_journal_entry_close_enabled() && trace) {
+               struct printbuf pbuf = PRINTBUF;
+               pbuf.atomic++;
+
+               prt_str(&pbuf, "entry size: ");
+               prt_human_readable_u64(&pbuf, vstruct_bytes(buf->data));
+               prt_newline(&pbuf);
+               bch2_prt_task_backtrace(&pbuf, current, 1, GFP_NOWAIT);
+               trace_journal_entry_close(c, pbuf.buf);
+               printbuf_exit(&pbuf);
+       }
+
        sectors = vstruct_blocks_plus(buf->data, c->block_bits,
                                      buf->u64s_reserved) << c->block_bits;
        BUG_ON(sectors > buf->sectors);
@@ -203,19 +308,17 @@ static void __journal_entry_close(struct journal *j, unsigned closed_val)
        buf->data->last_seq     = cpu_to_le64(buf->last_seq);
        BUG_ON(buf->last_seq > le64_to_cpu(buf->data->seq));
 
-       __bch2_journal_pin_put(j, le64_to_cpu(buf->data->seq));
-
        cancel_delayed_work(&j->write_work);
 
        bch2_journal_space_available(j);
 
-       bch2_journal_buf_put(j, old.idx);
+       __bch2_journal_buf_put(j, old.idx, le64_to_cpu(buf->data->seq));
 }
 
 void bch2_journal_halt(struct journal *j)
 {
        spin_lock(&j->lock);
-       __journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL);
+       __journal_entry_close(j, JOURNAL_ENTRY_ERROR_VAL, true);
        if (!j->err_seq)
                j->err_seq = journal_cur_seq(j);
        journal_wake(j);
@@ -229,7 +332,7 @@ static bool journal_entry_want_write(struct journal *j)
 
        /* Don't close it yet if we already have a write in flight: */
        if (ret)
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
        else if (nr_unwritten_journal_entries(j)) {
                struct journal_buf *buf = journal_cur_buf(j);
 
@@ -242,7 +345,7 @@ static bool journal_entry_want_write(struct journal *j)
        return ret;
 }
 
-static bool journal_entry_close(struct journal *j)
+bool bch2_journal_entry_close(struct journal *j)
 {
        bool ret;
 
@@ -314,13 +417,19 @@ static int journal_entry_open(struct journal *j)
        atomic64_inc(&j->seq);
        journal_pin_list_init(fifo_push_ref(&j->pin), 1);
 
+       BUG_ON(j->pin.back - 1 != atomic64_read(&j->seq));
+
        BUG_ON(j->buf + (journal_cur_seq(j) & JOURNAL_BUF_MASK) != buf);
 
        bkey_extent_init(&buf->key);
-       buf->noflush    = false;
-       buf->must_flush = false;
-       buf->separate_flush = false;
-       buf->flush_time = 0;
+       buf->noflush            = false;
+       buf->must_flush         = false;
+       buf->separate_flush     = false;
+       buf->flush_time         = 0;
+       buf->need_flush_to_write_buffer = true;
+       buf->write_started      = false;
+       buf->write_allocated    = false;
+       buf->write_done         = false;
 
        memset(buf->data, 0, sizeof(*buf->data));
        buf->data->seq  = cpu_to_le64(journal_cur_seq(j));
@@ -354,14 +463,10 @@ static int journal_entry_open(struct journal *j)
        } while ((v = atomic64_cmpxchg(&j->reservations.counter,
                                       old.v, new.v)) != old.v);
 
-       if (j->res_get_blocked_start)
-               bch2_time_stats_update(j->blocked_time,
-                                      j->res_get_blocked_start);
-       j->res_get_blocked_start = 0;
-
-       mod_delayed_work(c->io_complete_wq,
-                        &j->write_work,
-                        msecs_to_jiffies(c->opts.journal_flush_delay));
+       if (nr_unwritten_journal_entries(j) == 1)
+               mod_delayed_work(j->wq,
+                                &j->write_work,
+                                msecs_to_jiffies(c->opts.journal_flush_delay));
        journal_wake(j);
 
        if (j->early_journal_entries.nr)
@@ -374,7 +479,7 @@ static bool journal_quiesced(struct journal *j)
        bool ret = atomic64_read(&j->seq) == j->seq_ondisk;
 
        if (!ret)
-               journal_entry_close(j);
+               bch2_journal_entry_close(j);
        return ret;
 }
 
@@ -386,20 +491,16 @@ static void journal_quiesce(struct journal *j)
 static void journal_write_work(struct work_struct *work)
 {
        struct journal *j = container_of(work, struct journal, write_work.work);
-       struct bch_fs *c = container_of(j, struct bch_fs, journal);
-       long delta;
 
        spin_lock(&j->lock);
-       if (!__journal_entry_is_open(j->reservations))
-               goto unlock;
-
-       delta = journal_cur_buf(j)->expires - jiffies;
+       if (__journal_entry_is_open(j->reservations)) {
+               long delta = journal_cur_buf(j)->expires - jiffies;
 
-       if (delta > 0)
-               mod_delayed_work(c->io_complete_wq, &j->write_work, delta);
-       else
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
-unlock:
+               if (delta > 0)
+                       mod_delayed_work(j->wq, &j->write_work, delta);
+               else
+                       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
+       }
        spin_unlock(&j->lock);
 }
 
@@ -414,33 +515,32 @@ retry:
        if (journal_res_get_fast(j, res, flags))
                return 0;
 
-       if (bch2_journal_error(j))
-               return -BCH_ERR_erofs_journal_err;
+       if ((flags & BCH_WATERMARK_MASK) < j->watermark) {
+               ret = JOURNAL_ERR_journal_full;
+               can_discard = j->can_discard;
+               goto out;
+       }
 
-       spin_lock(&j->lock);
+       if (j->blocked)
+               return -BCH_ERR_journal_res_get_blocked;
 
-       /* check once more in case somebody else shut things down... */
-       if (bch2_journal_error(j)) {
-               spin_unlock(&j->lock);
+       if (bch2_journal_error(j))
                return -BCH_ERR_erofs_journal_err;
+
+       if (nr_unwritten_journal_entries(j) == ARRAY_SIZE(j->buf) && !journal_entry_is_open(j)) {
+               ret = JOURNAL_ERR_max_in_flight;
+               goto out;
        }
 
+       spin_lock(&j->lock);
+
        /*
         * Recheck after taking the lock, so we don't race with another thread
-        * that just did journal_entry_open() and call journal_entry_close()
+        * that just did journal_entry_open() and call bch2_journal_entry_close()
         * unnecessarily
         */
        if (journal_res_get_fast(j, res, flags)) {
-               spin_unlock(&j->lock);
-               return 0;
-       }
-
-       if ((flags & BCH_WATERMARK_MASK) < j->watermark) {
-               /*
-                * Don't want to close current journal entry, just need to
-                * invoke reclaim:
-                */
-               ret = JOURNAL_ERR_journal_full;
+               ret = 0;
                goto unlock;
        }
 
@@ -455,26 +555,31 @@ retry:
            buf->buf_size < JOURNAL_ENTRY_SIZE_MAX)
                j->buf_size_want = max(j->buf_size_want, buf->buf_size << 1);
 
-       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
-       ret = journal_entry_open(j);
-
-       if (ret == JOURNAL_ERR_max_in_flight)
-               trace_and_count(c, journal_entry_full, c);
+       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, false);
+       ret = journal_entry_open(j) ?: JOURNAL_ERR_retry;
 unlock:
-       if ((ret && ret != JOURNAL_ERR_insufficient_devices) &&
-           !j->res_get_blocked_start) {
-               j->res_get_blocked_start = local_clock() ?: 1;
-               trace_and_count(c, journal_full, c);
-       }
-
        can_discard = j->can_discard;
        spin_unlock(&j->lock);
-
-       if (!ret)
+out:
+       if (ret == JOURNAL_ERR_retry)
                goto retry;
+       if (!ret)
+               return 0;
+
        if (journal_error_check_stuck(j, ret, flags))
                ret = -BCH_ERR_journal_res_get_blocked;
 
+       if (ret == JOURNAL_ERR_max_in_flight &&
+           track_event_change(&c->times[BCH_TIME_blocked_journal_max_in_flight], true)) {
+
+               struct printbuf buf = PRINTBUF;
+               prt_printf(&buf, "seq %llu\n", journal_cur_seq(j));
+               bch2_journal_bufs_to_text(&buf, j);
+               trace_journal_entry_full(c, buf.buf);
+               printbuf_exit(&buf);
+               count_event(c, journal_entry_full);
+       }
+
        /*
         * Journal is full - can't rely on reclaim from work item due to
         * freezing:
@@ -514,42 +619,11 @@ int bch2_journal_res_get_slowpath(struct journal *j, struct journal_res *res,
        int ret;
 
        closure_wait_event(&j->async_wait,
-                  (ret = __journal_res_get(j, res, flags)) !=
-                  -BCH_ERR_journal_res_get_blocked||
+                  (ret = __journal_res_get(j, res, flags)) != -BCH_ERR_journal_res_get_blocked ||
                   (flags & JOURNAL_RES_GET_NONBLOCK));
        return ret;
 }
 
-/* journal_preres: */
-
-static bool journal_preres_available(struct journal *j,
-                                    struct journal_preres *res,
-                                    unsigned new_u64s,
-                                    unsigned flags)
-{
-       bool ret = bch2_journal_preres_get_fast(j, res, new_u64s, flags, true);
-
-       if (!ret && mutex_trylock(&j->reclaim_lock)) {
-               bch2_journal_reclaim(j);
-               mutex_unlock(&j->reclaim_lock);
-       }
-
-       return ret;
-}
-
-int __bch2_journal_preres_get(struct journal *j,
-                             struct journal_preres *res,
-                             unsigned new_u64s,
-                             unsigned flags)
-{
-       int ret;
-
-       closure_wait_event(&j->preres_wait,
-                  (ret = bch2_journal_error(j)) ||
-                  journal_preres_available(j, res, new_u64s, flags));
-       return ret;
-}
-
 /* journal_entry_res: */
 
 void bch2_journal_entry_res_resize(struct journal *j,
@@ -575,7 +649,7 @@ void bch2_journal_entry_res_resize(struct journal *j,
                /*
                 * Not enough room in current journal entry, have to flush it:
                 */
-               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
        } else {
                journal_cur_buf(j)->u64s_reserved += d;
        }
@@ -588,8 +662,13 @@ out:
 
 /**
  * bch2_journal_flush_seq_async - wait for a journal entry to be written
+ * @j:         journal object
+ * @seq:       seq to flush
+ * @parent:    closure object to wait with
+ * Returns:    1 if @seq has already been flushed, 0 if @seq is being flushed,
+ *             -EIO if @seq will never be flushed
  *
- * like bch2_journal_wait_on_seq, except that it triggers a write immediately if
+ * Like bch2_journal_wait_on_seq, except that it triggers a write immediately if
  * necessary
  */
 int bch2_journal_flush_seq_async(struct journal *j, u64 seq,
@@ -627,7 +706,7 @@ recheck_need_open:
                struct journal_res res = { 0 };
 
                if (journal_entry_is_open(j))
-                       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL);
+                       __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
 
                spin_unlock(&j->lock);
 
@@ -689,7 +768,7 @@ int bch2_journal_flush_seq(struct journal *j, u64 seq)
        ret = wait_event_interruptible(j->wait, (ret2 = bch2_journal_flush_seq_async(j, seq, NULL)));
 
        if (!ret)
-               bch2_time_stats_update(j->flush_seq_time, start_time);
+               time_stats_update(j->flush_seq_time, start_time);
 
        return ret ?: ret2 < 0 ? ret2 : 0;
 }
@@ -791,6 +870,48 @@ void bch2_journal_block(struct journal *j)
        journal_quiesce(j);
 }
 
+static struct journal_buf *__bch2_next_write_buffer_flush_journal_buf(struct journal *j, u64 max_seq)
+{
+       struct journal_buf *ret = NULL;
+
+       mutex_lock(&j->buf_lock);
+       spin_lock(&j->lock);
+       max_seq = min(max_seq, journal_cur_seq(j));
+
+       for (u64 seq = journal_last_unwritten_seq(j);
+            seq <= max_seq;
+            seq++) {
+               unsigned idx = seq & JOURNAL_BUF_MASK;
+               struct journal_buf *buf = j->buf + idx;
+
+               if (buf->need_flush_to_write_buffer) {
+                       if (seq == journal_cur_seq(j))
+                               __journal_entry_close(j, JOURNAL_ENTRY_CLOSED_VAL, true);
+
+                       union journal_res_state s;
+                       s.v = atomic64_read_acquire(&j->reservations.counter);
+
+                       ret = journal_state_count(s, idx)
+                               ? ERR_PTR(-EAGAIN)
+                               : buf;
+                       break;
+               }
+       }
+
+       spin_unlock(&j->lock);
+       if (IS_ERR_OR_NULL(ret))
+               mutex_unlock(&j->buf_lock);
+       return ret;
+}
+
+struct journal_buf *bch2_next_write_buffer_flush_journal_buf(struct journal *j, u64 max_seq)
+{
+       struct journal_buf *ret;
+
+       wait_event(j->wait, (ret = __bch2_next_write_buffer_flush_journal_buf(j, max_seq)) != ERR_PTR(-EAGAIN));
+       return ret;
+}
+
 /* allocate journal on a device: */
 
 static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
@@ -829,12 +950,12 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
                                break;
 
                        ret = bch2_trans_run(c,
-                               bch2_trans_mark_metadata_bucket(&trans, ca,
+                               bch2_trans_mark_metadata_bucket(trans, ca,
                                                ob[nr_got]->bucket, BCH_DATA_journal,
                                                ca->mi.bucket_size));
                        if (ret) {
                                bch2_open_bucket_put(c, ob[nr_got]);
-                               bch_err(c, "error marking new journal buckets: %s", bch2_err_str(ret));
+                               bch_err_msg(c, ret, "marking new journal buckets");
                                break;
                        }
 
@@ -910,7 +1031,7 @@ err_unblock:
        if (ret && !new_fs)
                for (i = 0; i < nr_got; i++)
                        bch2_trans_run(c,
-                               bch2_trans_mark_metadata_bucket(&trans, ca,
+                               bch2_trans_mark_metadata_bucket(trans, ca,
                                                bu[i], BCH_DATA_free, 0));
 err_free:
        if (!new_fs)
@@ -944,7 +1065,7 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
                goto unlock;
 
        while (ja->nr < nr) {
-               struct disk_reservation disk_res = { 0, 0 };
+               struct disk_reservation disk_res = { 0, 0, 0 };
 
                /*
                 * note: journal buckets aren't really counted as _sectors_ used yet, so
@@ -972,8 +1093,7 @@ int bch2_set_nr_journal_buckets(struct bch_fs *c, struct bch_dev *ca,
                        break;
        }
 
-       if (ret)
-               bch_err_fn(c, ret);
+       bch_err_fn(c, ret);
 unlock:
        up_write(&c->state_lock);
        return ret;
@@ -1003,11 +1123,26 @@ int bch2_dev_journal_alloc(struct bch_dev *ca)
 
        ret = __bch2_set_nr_journal_buckets(ca, nr, true, NULL);
 err:
-       if (ret)
-               bch_err_fn(ca, ret);
+       bch_err_fn(ca, ret);
        return ret;
 }
 
+int bch2_fs_journal_alloc(struct bch_fs *c)
+{
+       for_each_online_member(c, ca) {
+               if (ca->journal.nr)
+                       continue;
+
+               int ret = bch2_dev_journal_alloc(ca);
+               if (ret) {
+                       percpu_ref_put(&ca->io_ref);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
 /* startup/shutdown: */
 
 static bool bch2_journal_writing_to_device(struct journal *j, unsigned dev_idx)
@@ -1039,7 +1174,7 @@ void bch2_fs_journal_stop(struct journal *j)
        bch2_journal_reclaim_stop(j);
        bch2_journal_flush_all_pins(j);
 
-       wait_event(j->wait, journal_entry_close(j));
+       wait_event(j->wait, bch2_journal_entry_close(j));
 
        /*
         * Always write a new journal entry, to make sure the clock hands are up
@@ -1063,7 +1198,6 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
        struct journal_replay *i, **_i;
        struct genradix_iter iter;
        bool had_entries = false;
-       unsigned ptr;
        u64 last_seq = cur_seq, nr, seq;
 
        genradix_for_each_reverse(&c->journal_entries, iter, _i) {
@@ -1117,8 +1251,8 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
                p = journal_seq_pin(j, seq);
 
                p->devs.nr = 0;
-               for (ptr = 0; ptr < i->nr_ptrs; ptr++)
-                       bch2_dev_list_add_dev(&p->devs, i->ptrs[ptr].dev);
+               darray_for_each(i->ptrs, ptr)
+                       bch2_dev_list_add_dev(&p->devs, ptr->dev);
 
                had_entries = true;
        }
@@ -1146,30 +1280,33 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
 
 void bch2_dev_journal_exit(struct bch_dev *ca)
 {
-       kfree(ca->journal.bio);
-       kfree(ca->journal.buckets);
-       kfree(ca->journal.bucket_seq);
+       struct journal_device *ja = &ca->journal;
 
-       ca->journal.bio         = NULL;
-       ca->journal.buckets     = NULL;
-       ca->journal.bucket_seq  = NULL;
+       for (unsigned i = 0; i < ARRAY_SIZE(ja->bio); i++) {
+               kfree(ja->bio[i]);
+               ja->bio[i] = NULL;
+       }
+
+       kfree(ja->buckets);
+       kfree(ja->bucket_seq);
+       ja->buckets     = NULL;
+       ja->bucket_seq  = NULL;
 }
 
 int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 {
        struct journal_device *ja = &ca->journal;
        struct bch_sb_field_journal *journal_buckets =
-               bch2_sb_get_journal(sb);
+               bch2_sb_field_get(sb, journal);
        struct bch_sb_field_journal_v2 *journal_buckets_v2 =
-               bch2_sb_get_journal_v2(sb);
-       unsigned i, nr_bvecs;
+               bch2_sb_field_get(sb, journal_v2);
 
        ja->nr = 0;
 
        if (journal_buckets_v2) {
                unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
 
-               for (i = 0; i < nr; i++)
+               for (unsigned i = 0; i < nr; i++)
                        ja->nr += le64_to_cpu(journal_buckets_v2->d[i].nr);
        } else if (journal_buckets) {
                ja->nr = bch2_nr_journal_buckets(journal_buckets);
@@ -1179,13 +1316,18 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
        if (!ja->bucket_seq)
                return -BCH_ERR_ENOMEM_dev_journal_init;
 
-       nr_bvecs = DIV_ROUND_UP(JOURNAL_ENTRY_SIZE_MAX, PAGE_SIZE);
+       unsigned nr_bvecs = DIV_ROUND_UP(JOURNAL_ENTRY_SIZE_MAX, PAGE_SIZE);
 
-       ca->journal.bio = bio_kmalloc(nr_bvecs, GFP_KERNEL);
-       if (!ca->journal.bio)
-               return -BCH_ERR_ENOMEM_dev_journal_init;
+       for (unsigned i = 0; i < ARRAY_SIZE(ja->bio); i++) {
+               ja->bio[i] = kmalloc(struct_size(ja->bio[i], bio.bi_inline_vecs,
+                                    nr_bvecs), GFP_KERNEL);
+               if (!ja->bio[i])
+                       return -BCH_ERR_ENOMEM_dev_journal_init;
 
-       bio_init(ca->journal.bio, NULL, ca->journal.bio->bi_inline_vecs, nr_bvecs, 0);
+               ja->bio[i]->ca = ca;
+               ja->bio[i]->buf_idx = i;
+               bio_init(&ja->bio[i]->bio, NULL, ja->bio[i]->bio.bi_inline_vecs, nr_bvecs, 0);
+       }
 
        ja->buckets = kcalloc(ja->nr, sizeof(u64), GFP_KERNEL);
        if (!ja->buckets)
@@ -1193,14 +1335,14 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 
        if (journal_buckets_v2) {
                unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
-               unsigned j, dst = 0;
+               unsigned dst = 0;
 
-               for (i = 0; i < nr; i++)
-                       for (j = 0; j < le64_to_cpu(journal_buckets_v2->d[i].nr); j++)
+               for (unsigned i = 0; i < nr; i++)
+                       for (unsigned j = 0; j < le64_to_cpu(journal_buckets_v2->d[i].nr); j++)
                                ja->buckets[dst++] =
                                        le64_to_cpu(journal_buckets_v2->d[i].start) + j;
        } else if (journal_buckets) {
-               for (i = 0; i < ja->nr; i++)
+               for (unsigned i = 0; i < ja->nr; i++)
                        ja->buckets[i] = le64_to_cpu(journal_buckets->buckets[i]);
        }
 
@@ -1209,20 +1351,21 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 
 void bch2_fs_journal_exit(struct journal *j)
 {
-       unsigned i;
+       if (j->wq)
+               destroy_workqueue(j->wq);
 
        darray_exit(&j->early_journal_entries);
 
-       for (i = 0; i < ARRAY_SIZE(j->buf); i++)
-               kvpfree(j->buf[i].data, j->buf[i].buf_size);
+       for (unsigned i = 0; i < ARRAY_SIZE(j->buf); i++)
+               kvfree(j->buf[i].data);
        free_fifo(&j->pin);
 }
 
 int bch2_fs_journal_init(struct journal *j)
 {
        static struct lock_class_key res_key;
-       unsigned i;
 
+       mutex_init(&j->buf_lock);
        spin_lock_init(&j->lock);
        spin_lock_init(&j->err_lock);
        init_waitqueue_head(&j->wait);
@@ -1241,14 +1384,20 @@ int bch2_fs_journal_init(struct journal *j)
        if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)))
                return -BCH_ERR_ENOMEM_journal_pin_fifo;
 
-       for (i = 0; i < ARRAY_SIZE(j->buf); i++) {
+       for (unsigned i = 0; i < ARRAY_SIZE(j->buf); i++) {
                j->buf[i].buf_size = JOURNAL_ENTRY_SIZE_MIN;
-               j->buf[i].data = kvpmalloc(j->buf[i].buf_size, GFP_KERNEL);
+               j->buf[i].data = kvmalloc(j->buf[i].buf_size, GFP_KERNEL);
                if (!j->buf[i].data)
                        return -BCH_ERR_ENOMEM_journal_buf;
+               j->buf[i].idx = i;
        }
 
        j->pin.front = j->pin.back = 1;
+
+       j->wq = alloc_workqueue("bcachefs_journal",
+                               WQ_HIGHPRI|WQ_FREEZABLE|WQ_UNBOUND|WQ_MEM_RECLAIM, 512);
+       if (!j->wq)
+               return -BCH_ERR_ENOMEM_fs_other_alloc;
        return 0;
 }
 
@@ -1258,10 +1407,8 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
 {
        struct bch_fs *c = container_of(j, struct bch_fs, journal);
        union journal_res_state s;
-       struct bch_dev *ca;
        unsigned long now = jiffies;
-       u64 seq;
-       unsigned i;
+       u64 nr_writes = j->nr_flush_writes + j->nr_noflush_writes;
 
        if (!out->nr_tabstops)
                printbuf_tabstop_push(out, 24);
@@ -1273,21 +1420,24 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
        prt_printf(out, "dirty journal entries:\t%llu/%llu\n",  fifo_used(&j->pin), j->pin.size);
        prt_printf(out, "seq:\t\t\t%llu\n",                     journal_cur_seq(j));
        prt_printf(out, "seq_ondisk:\t\t%llu\n",                j->seq_ondisk);
-       prt_printf(out, "last_seq:\t\t%llu\n",          journal_last_seq(j));
+       prt_printf(out, "last_seq:\t\t%llu\n",                  journal_last_seq(j));
        prt_printf(out, "last_seq_ondisk:\t%llu\n",             j->last_seq_ondisk);
-       prt_printf(out, "flushed_seq_ondisk:\t%llu\n",  j->flushed_seq_ondisk);
-       prt_printf(out, "prereserved:\t\t%u/%u\n",              j->prereserved.reserved, j->prereserved.remaining);
-       prt_printf(out, "watermark:\t\t%s\n",           bch2_watermarks[j->watermark]);
-       prt_printf(out, "each entry reserved:\t%u\n",   j->entry_u64s_reserved);
+       prt_printf(out, "flushed_seq_ondisk:\t%llu\n",          j->flushed_seq_ondisk);
+       prt_printf(out, "watermark:\t\t%s\n",                   bch2_watermarks[j->watermark]);
+       prt_printf(out, "each entry reserved:\t%u\n",           j->entry_u64s_reserved);
        prt_printf(out, "nr flush writes:\t%llu\n",             j->nr_flush_writes);
-       prt_printf(out, "nr noflush writes:\t%llu\n",   j->nr_noflush_writes);
-       prt_printf(out, "nr direct reclaim:\t%llu\n",   j->nr_direct_reclaim);
+       prt_printf(out, "nr noflush writes:\t%llu\n",           j->nr_noflush_writes);
+       prt_printf(out, "average write size:\t");
+       prt_human_readable_u64(out, nr_writes ? div64_u64(j->entry_bytes_written, nr_writes) : 0);
+       prt_newline(out);
+       prt_printf(out, "nr direct reclaim:\t%llu\n",           j->nr_direct_reclaim);
        prt_printf(out, "nr background reclaim:\t%llu\n",       j->nr_background_reclaim);
        prt_printf(out, "reclaim kicked:\t\t%u\n",              j->reclaim_kicked);
-       prt_printf(out, "reclaim runs in:\t%u ms\n",    time_after(j->next_reclaim, now)
+       prt_printf(out, "reclaim runs in:\t%u ms\n",            time_after(j->next_reclaim, now)
               ? jiffies_to_msecs(j->next_reclaim - jiffies) : 0);
-       prt_printf(out, "current entry sectors:\t%u\n", j->cur_entry_sectors);
-       prt_printf(out, "current entry error:\t%s\n",   bch2_journal_errors[j->cur_entry_error]);
+       prt_printf(out, "blocked:\t\t%u\n",                     j->blocked);
+       prt_printf(out, "current entry sectors:\t%u\n",         j->cur_entry_sectors);
+       prt_printf(out, "current entry error:\t%s\n",           bch2_journal_errors[j->cur_entry_error]);
        prt_printf(out, "current entry:\t\t");
 
        switch (s.cur_entry_offset) {
@@ -1303,35 +1453,9 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
        }
 
        prt_newline(out);
-
-       for (seq = journal_cur_seq(j);
-            seq >= journal_last_unwritten_seq(j);
-            --seq) {
-               i = seq & JOURNAL_BUF_MASK;
-
-               prt_printf(out, "unwritten entry:");
-               prt_tab(out);
-               prt_printf(out, "%llu", seq);
-               prt_newline(out);
-               printbuf_indent_add(out, 2);
-
-               prt_printf(out, "refcount:");
-               prt_tab(out);
-               prt_printf(out, "%u", journal_state_count(s, i));
-               prt_newline(out);
-
-               prt_printf(out, "sectors:");
-               prt_tab(out);
-               prt_printf(out, "%u", j->buf[i].sectors);
-               prt_newline(out);
-
-               prt_printf(out, "expires");
-               prt_tab(out);
-               prt_printf(out, "%li jiffies", j->buf[i].expires - jiffies);
-               prt_newline(out);
-
-               printbuf_indent_sub(out, 2);
-       }
+       prt_printf(out, "unwritten entries:");
+       prt_newline(out);
+       bch2_journal_bufs_to_text(out, j);
 
        prt_printf(out,
               "replay done:\t\t%i\n",
@@ -1351,8 +1475,7 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
               j->space[journal_space_total].next_entry,
               j->space[journal_space_total].total);
 
-       for_each_member_device_rcu(ca, c, i,
-                                  &c->rw_devs[BCH_DATA_journal]) {
+       for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
                struct journal_device *ja = &ca->journal;
 
                if (!test_bit(ca->dev_idx, c->rw_devs[BCH_DATA_journal].d))
@@ -1361,7 +1484,7 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
                if (!ja->nr)
                        continue;
 
-               prt_printf(out, "dev %u:\n",            i);
+               prt_printf(out, "dev %u:\n",            ca->dev_idx);
                prt_printf(out, "\tnr\t\t%u\n",         ja->nr);
                prt_printf(out, "\tbucket size\t%u\n",  ca->mi.bucket_size);
                prt_printf(out, "\tavailable\t%u:%u\n", bch2_journal_dev_buckets_available(j, ja, journal_space_discarded), ja->sectors_free);
@@ -1387,7 +1510,6 @@ bool bch2_journal_seq_pins_to_text(struct printbuf *out, struct journal *j, u64
 {
        struct journal_entry_pin_list *pin_list;
        struct journal_entry_pin *pin;
-       unsigned i;
 
        spin_lock(&j->lock);
        *seq = max(*seq, j->pin.front);
@@ -1405,7 +1527,7 @@ bool bch2_journal_seq_pins_to_text(struct printbuf *out, struct journal *j, u64
        prt_newline(out);
        printbuf_indent_add(out, 2);
 
-       for (i = 0; i < ARRAY_SIZE(pin_list->list); i++)
+       for (unsigned i = 0; i < ARRAY_SIZE(pin_list->list); i++)
                list_for_each_entry(pin, &pin_list->list[i], list) {
                        prt_printf(out, "\t%px %ps", pin, pin->flush);
                        prt_newline(out);