Messages in this thread Patch in this message | | | From | Johannes Thumshirn <> | Date | Thu, 23 Nov 2023 07:47:16 -0800 | Subject | [PATCH v2 2/5] btrfs: zoned: don't clear dirty flag of extent buffer |
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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 <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> --- 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 460b88526f56..9c09062d3d0a 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 49514ef829fb..c378094b5cc8 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3748,6 +3748,20 @@ 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; @@ -4139,8 +4153,6 @@ 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 b9bfde6fb929..ed8e002b33e7 100644 --- a/fs/btrfs/zoned.c +++ b/fs/btrfs/zoned.c @@ -1722,7 +1722,8 @@ 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); -- 2.41.0
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