From b6bfebc13218f1fc1502041a810919d3a81b8b4e Mon Sep 17 00:00:00 2001 From: Stefan Behrens Date: Fri, 2 Nov 2012 16:44:58 +0100 Subject: [PATCH] Btrfs: cleanup scrub bio and worker wait code Just move some code into functions to make everything more readable. Signed-off-by: Stefan Behrens Signed-off-by: Chris Mason --- fs/btrfs/scrub.c | 106 +++++++++++++++++++++++++++++++---------------- 1 file changed, 71 insertions(+), 35 deletions(-) diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index fcd5bccaa4ed..a67b1a17a009 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2011 STRATO. All rights reserved. + * Copyright (C) 2011, 2012 STRATO. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public @@ -104,8 +104,8 @@ struct scrub_ctx { struct btrfs_root *dev_root; int first_free; int curr; - atomic_t in_flight; - atomic_t fixup_cnt; + atomic_t bios_in_flight; + atomic_t workers_pending; spinlock_t list_lock; wait_queue_head_t list_wait; u16 csum_size; @@ -146,6 +146,10 @@ struct scrub_warning { }; +static void scrub_pending_bio_inc(struct scrub_ctx *sctx); +static void scrub_pending_bio_dec(struct scrub_ctx *sctx); +static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx); +static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx); static int scrub_handle_errored_block(struct scrub_block *sblock_to_check); static int scrub_setup_recheck_block(struct scrub_ctx *sctx, struct btrfs_mapping_tree *map_tree, @@ -184,6 +188,59 @@ static void scrub_bio_end_io_worker(struct btrfs_work *work); static void scrub_block_complete(struct scrub_block *sblock); +static void scrub_pending_bio_inc(struct scrub_ctx *sctx) +{ + atomic_inc(&sctx->bios_in_flight); +} + +static void scrub_pending_bio_dec(struct scrub_ctx *sctx) +{ + atomic_dec(&sctx->bios_in_flight); + wake_up(&sctx->list_wait); +} + +/* + * used for workers that require transaction commits (i.e., for the + * NOCOW case) + */ +static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) +{ + struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; + + /* + * increment scrubs_running to prevent cancel requests from + * completing as long as a worker is running. we must also + * increment scrubs_paused to prevent deadlocking on pause + * requests used for transactions commits (as the worker uses a + * transaction context). it is safe to regard the worker + * as paused for all matters practical. effectively, we only + * avoid cancellation requests from completing. + */ + mutex_lock(&fs_info->scrub_lock); + atomic_inc(&fs_info->scrubs_running); + atomic_inc(&fs_info->scrubs_paused); + mutex_unlock(&fs_info->scrub_lock); + atomic_inc(&sctx->workers_pending); +} + +/* used for workers that require transaction commits */ +static void scrub_pending_trans_workers_dec(struct scrub_ctx *sctx) +{ + struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; + + /* + * see scrub_pending_trans_workers_inc() why we're pretending + * to be paused in the scrub counters + */ + mutex_lock(&fs_info->scrub_lock); + atomic_dec(&fs_info->scrubs_running); + atomic_dec(&fs_info->scrubs_paused); + mutex_unlock(&fs_info->scrub_lock); + atomic_dec(&sctx->workers_pending); + wake_up(&fs_info->scrub_pause_wait); + wake_up(&sctx->list_wait); +} + static void scrub_free_csums(struct scrub_ctx *sctx) { while (!list_empty(&sctx->csum_list)) { @@ -264,8 +321,8 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev) sctx->nodesize = dev->dev_root->nodesize; sctx->leafsize = dev->dev_root->leafsize; sctx->sectorsize = dev->dev_root->sectorsize; - atomic_set(&sctx->in_flight, 0); - atomic_set(&sctx->fixup_cnt, 0); + atomic_set(&sctx->bios_in_flight, 0); + atomic_set(&sctx->workers_pending, 0); atomic_set(&sctx->cancel_req, 0); sctx->csum_size = btrfs_super_csum_size(fs_info->super_copy); INIT_LIST_HEAD(&sctx->csum_list); @@ -609,14 +666,7 @@ out: btrfs_free_path(path); kfree(fixup); - /* see caller why we're pretending to be paused in the scrub counters */ - mutex_lock(&fs_info->scrub_lock); - atomic_dec(&fs_info->scrubs_running); - atomic_dec(&fs_info->scrubs_paused); - mutex_unlock(&fs_info->scrub_lock); - atomic_dec(&sctx->fixup_cnt); - wake_up(&fs_info->scrub_pause_wait); - wake_up(&sctx->list_wait); + scrub_pending_trans_workers_dec(sctx); } /* @@ -789,20 +839,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) fixup_nodatasum->logical = logical; fixup_nodatasum->root = fs_info->extent_root; fixup_nodatasum->mirror_num = failed_mirror_index + 1; - /* - * increment scrubs_running to prevent cancel requests from - * completing as long as a fixup worker is running. we must also - * increment scrubs_paused to prevent deadlocking on pause - * requests used for transactions commits (as the worker uses a - * transaction context). it is safe to regard the fixup worker - * as paused for all matters practical. effectively, we only - * avoid cancellation requests from completing. - */ - mutex_lock(&fs_info->scrub_lock); - atomic_inc(&fs_info->scrubs_running); - atomic_inc(&fs_info->scrubs_paused); - mutex_unlock(&fs_info->scrub_lock); - atomic_inc(&sctx->fixup_cnt); + scrub_pending_trans_workers_inc(sctx); fixup_nodatasum->work.func = scrub_fixup_nodatasum; btrfs_queue_worker(&fs_info->scrub_workers, &fixup_nodatasum->work); @@ -1491,7 +1528,7 @@ static void scrub_submit(struct scrub_ctx *sctx) sbio = sctx->bios[sctx->curr]; sctx->curr = -1; - atomic_inc(&sctx->in_flight); + scrub_pending_bio_inc(sctx); btrfsic_submit_bio(READ, sbio->bio); } @@ -1692,8 +1729,7 @@ static void scrub_bio_end_io_worker(struct btrfs_work *work) sbio->next_free = sctx->first_free; sctx->first_free = sbio->index; spin_unlock(&sctx->list_lock); - atomic_dec(&sctx->in_flight); - wake_up(&sctx->list_wait); + scrub_pending_bio_dec(sctx); } static void scrub_block_complete(struct scrub_block *sblock) @@ -1863,7 +1899,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, logical = base + offset; wait_event(sctx->list_wait, - atomic_read(&sctx->in_flight) == 0); + atomic_read(&sctx->bios_in_flight) == 0); atomic_inc(&fs_info->scrubs_paused); wake_up(&fs_info->scrub_pause_wait); @@ -1928,7 +1964,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, /* push queued extents */ scrub_submit(sctx); wait_event(sctx->list_wait, - atomic_read(&sctx->in_flight) == 0); + atomic_read(&sctx->bios_in_flight) == 0); atomic_inc(&fs_info->scrubs_paused); wake_up(&fs_info->scrub_pause_wait); mutex_lock(&fs_info->scrub_lock); @@ -2218,7 +2254,7 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx, if (ret) return ret; } - wait_event(sctx->list_wait, atomic_read(&sctx->in_flight) == 0); + wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); return 0; } @@ -2363,11 +2399,11 @@ int btrfs_scrub_dev(struct btrfs_root *root, u64 devid, u64 start, u64 end, if (!ret) ret = scrub_enumerate_chunks(sctx, dev, start, end); - wait_event(sctx->list_wait, atomic_read(&sctx->in_flight) == 0); + wait_event(sctx->list_wait, atomic_read(&sctx->bios_in_flight) == 0); atomic_dec(&fs_info->scrubs_running); wake_up(&fs_info->scrub_pause_wait); - wait_event(sctx->list_wait, atomic_read(&sctx->fixup_cnt) == 0); + wait_event(sctx->list_wait, atomic_read(&sctx->workers_pending) == 0); if (progress) memcpy(progress, &sctx->stat, sizeof(*progress)); -- 2.30.2