From aa6313e6ff2bfbf736a2739047bba355d8241584 Mon Sep 17 00:00:00 2001 From: Johannes Thumshirn Date: Thu, 23 Nov 2023 07:47:16 -0800 Subject: [PATCH] btrfs: zoned: don't clear dirty flag of extent buffer One a zoned filesystem, never clear the dirty flag of an extent buffer, but instead mark it as zeroout. On writeout, when encountering a marked extent_buffer, zero it out. Reviewed-by: Christoph Hellwig Reviewed-by: Josef Bacik Signed-off-by: Johannes Thumshirn Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 7 ++++++- fs/btrfs/extent_io.c | 16 ++++++++++++++-- fs/btrfs/zoned.c | 3 ++- 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 21c7835b46ec..7b55b59115e7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -254,8 +254,13 @@ blk_status_t btree_csum_one_bio(struct btrfs_bio *bbio) if (WARN_ON_ONCE(bbio->bio.bi_iter.bi_size != eb->len)) return BLK_STS_IOERR; + /* + * If an extent_buffer is marked as EXTENT_BUFFER_ZONED_ZEROOUT, don't + * checksum it but zero-out its content. This is done to preserve + * ordering of I/O without unnecessarily writing out data. + */ if (test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags)) { - WARN_ON_ONCE(found_start != 0); + memzero_extent_buffer(eb, 0, eb->len); return BLK_STS_OK; } diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 85cee54200ce..671010de7964 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3761,6 +3761,20 @@ void btrfs_clear_buffer_dirty(struct btrfs_trans_handle *trans, if (trans && btrfs_header_generation(eb) != trans->transid) return; + /* + * Instead of clearing the dirty flag off of the buffer, mark it as + * EXTENT_BUFFER_ZONED_ZEROOUT. This allows us to preserve + * write-ordering in zoned mode, without the need to later re-dirty + * the extent_buffer. + * + * The actual zeroout of the buffer will happen later in + * btree_csum_one_bio. + */ + if (btrfs_is_zoned(fs_info)) { + set_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags); + return; + } + if (!test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) return; @@ -4152,8 +4166,6 @@ static void __write_extent_buffer(const struct extent_buffer *eb, /* For unmapped (dummy) ebs, no need to check their uptodate status. */ const bool check_uptodate = !test_bit(EXTENT_BUFFER_UNMAPPED, &eb->bflags); - WARN_ON(test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags)); - if (check_eb_range(eb, start, len)) return; diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c index f1bcf2ac6180..2c7fe6699cf4 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -1713,7 +1713,8 @@ void btrfs_redirty_list_add(struct btrfs_transaction *trans, btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN)) return; - ASSERT(!test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); + ASSERT(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); + ASSERT(test_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags)); memzero_extent_buffer(eb, 0, eb->len); set_bit(EXTENT_BUFFER_ZONED_ZEROOUT, &eb->bflags);