From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <wqu@suse.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [Patch v2 05/42] btrfs: refactor submit_extent_page() to make bio and its flag tracing easier
Date: Fri, 14 May 2021 01:03:02 +0200 [thread overview]
Message-ID: <20210513230302.GO7604@twin.jikos.cz> (raw)
In-Reply-To: <20210427230349.369603-6-wqu@suse.com>
On Wed, Apr 28, 2021 at 07:03:12AM +0800, Qu Wenruo wrote:
> There are a lot of code inside extent_io.c needs both "struct bio
> **bio_ret" and "unsigned long prev_bio_flags", along with some parameter
> like "unsigned long bio_flags".
>
> Such strange parameters are here for bio assembly.
>
> For example, we have such inode page layout:
>
> 0 4K 8K 12K
> |<-- Extent A-->|<- EB->|
>
> Then what we do is:
> - Page [0, 4K)
> *bio_ret = NULL
> So we allocate a new bio to bio_ret,
> Add page [0, 4K) to *bio_ret.
>
> - Page [4K, 8K)
> *bio_ret != NULL
> We found this page is continuous to *bio_ret,
> and if we're not at stripe boundary, we
> add page [4K, 8K) to *bio_ret.
>
> - Page [8K, 12K)
> *bio_ret != NULL
> But we found this page is not continuous, so
> we submit *bio_ret, then allocate a new bio,
> and add page [8K, 12K) to the new bio.
>
> This means we need to record both the bio and its bio_flag, but we
> record them manually using those strange parameter list, other than
> encapsulating them into their own structure.
>
> So this patch will introduce a new structure, btrfs_bio_ctrl, to record
> both the bio, and its bio_flags.
>
> Also, in above case, for all pages added to the bio, we need to check if
> the new page crosses stripe boundary.
> This check itself can be time consuming, and we don't really need to do
> that for each page.
>
> This patch also integrate the stripe boundary check into btrfs_bio_ctrl.
> When a new bio is allocated, the stripe and ordered extent boundary is
> also calculated, so no matter how large the bio will be, we only
> calculate the boundaries once, to save some CPU time.
>
> The following functions/structures are affected:
> - struct extent_page_data
> Replace its bio pointer with structure btrfs_bio_ctrl (embedded
> structure, not pointer)
>
> - end_write_bio()
> - flush_write_bio()
> Just change how bio is fetched
>
> - btrfs_bio_add_page()
> Use pre-calculated boundaries instead of re-calculating them.
> And use @bio_ctrl to replace @bio and @prev_bio_flags.
>
> - calc_bio_boundaries()
> New function
>
> - submit_extent_page() callers
> - btrfs_do_readpage() callers
> - contiguous_readpages() callers
> To Use @bio_ctrl to replace @bio and @prev_bio_flags, and how to grab
> bio.
>
> - btrfs_bio_fits_in_ordered_extent()
> Removed, as now the ordered extent size limit is done at bio
> allocation time, no need to check for each page range.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
> fs/btrfs/ctree.h | 2 -
> fs/btrfs/extent_io.c | 214 ++++++++++++++++++++++++++++---------------
> fs/btrfs/extent_io.h | 13 ++-
> fs/btrfs/inode.c | 36 +-------
> 4 files changed, 154 insertions(+), 111 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 278e0cbc9a98..b94790583008 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3146,8 +3146,6 @@ void btrfs_split_delalloc_extent(struct inode *inode,
> struct extent_state *orig, u64 split);
> int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
> unsigned long bio_flags);
> -bool btrfs_bio_fits_in_ordered_extent(struct page *page, struct bio *bio,
> - unsigned int size);
> void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end);
> vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf);
> int btrfs_readpage(struct file *file, struct page *page);
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 8e18dc9a415d..949b603e7aa3 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -136,7 +136,7 @@ struct tree_entry {
> };
>
> struct extent_page_data {
> - struct bio *bio;
> + struct btrfs_bio_ctrl bio_ctrl;
> /* tells writepage not to lock the state bits for this range
> * it still does the unlocking
> */
> @@ -185,10 +185,12 @@ int __must_check submit_one_bio(struct bio *bio, int mirror_num,
> /* Cleanup unsubmitted bios */
> static void end_write_bio(struct extent_page_data *epd, int ret)
> {
> - if (epd->bio) {
> - epd->bio->bi_status = errno_to_blk_status(ret);
> - bio_endio(epd->bio);
> - epd->bio = NULL;
> + struct bio *bio = epd->bio_ctrl.bio;
We've been using _ctl suffix for the control structures that affect
behaviour of functions that take it as a parameter. I haven't modified
the patch to avoid conflicts with other patches but as a further cleanup
it would be good to get that unified to _ctl.
> static int submit_extent_page(unsigned int opf,
> struct writeback_control *wbc,
> + struct btrfs_bio_ctrl *bio_ctrl,
> struct page *page, u64 disk_bytenr,
> size_t size, unsigned long pg_offset,
> - struct bio **bio_ret,
> bio_end_io_t end_io_func,
> int mirror_num,
> - unsigned long prev_bio_flags,
> unsigned long bio_flags,
> bool force_bio_submit)
This function has been a challenge for anybody who likes to do cleanups.
I have a few branches that try to do so but no luck yet, so I appreciate
any reduction of the parameters with potential to move more of them to
the control structure.
next prev parent reply other threads:[~2021-05-13 23:05 UTC|newest]
Thread overview: 117+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-27 23:03 [Patch v2 00/42] btrfs: add data write support for subpage Qu Wenruo
2021-04-27 23:03 ` [Patch v2 01/42] btrfs: scrub: fix subpage scrub repair error caused by hardcoded PAGE_SIZE Qu Wenruo
2021-05-13 22:57 ` David Sterba
2021-05-13 23:32 ` Qu Wenruo
2021-04-27 23:03 ` [Patch v2 02/42] btrfs: make free space cache size consistent across different PAGE_SIZE Qu Wenruo
2021-04-27 23:03 ` [Patch v2 03/42] btrfs: remove the unused parameter @len for btrfs_bio_fits_in_stripe() Qu Wenruo
2021-05-13 22:58 ` David Sterba
2021-05-13 23:07 ` David Sterba
2021-04-27 23:03 ` [Patch v2 04/42] btrfs: allow btrfs_bio_fits_in_stripe() to accept bio without any page Qu Wenruo
2021-04-27 23:03 ` [Patch v2 05/42] btrfs: refactor submit_extent_page() to make bio and its flag tracing easier Qu Wenruo
2021-05-13 23:03 ` David Sterba [this message]
2021-05-21 11:06 ` Johannes Thumshirn
2021-05-21 11:26 ` Qu Wenruo
2021-05-21 13:30 ` David Sterba
2021-04-27 23:03 ` [Patch v2 06/42] btrfs: make subpage metadata write path to call its own endio functions Qu Wenruo
2021-04-27 23:03 ` [Patch v2 07/42] btrfs: pass btrfs_inode into btrfs_writepage_endio_finish_ordered() Qu Wenruo
2021-05-13 23:06 ` David Sterba
2021-05-13 23:35 ` Qu Wenruo
2021-05-21 14:27 ` Josef Bacik
2021-05-21 20:22 ` David Sterba
2021-05-22 0:24 ` Qu Wenruo
2021-05-23 7:40 ` Qu Wenruo
2021-05-23 13:43 ` Josef Bacik
2021-05-23 13:50 ` Qu Wenruo
2021-05-23 14:08 ` Josef Bacik
2021-04-27 23:03 ` [Patch v2 08/42] btrfs: make Private2 lifespan more consistent Qu Wenruo
2021-04-27 23:03 ` [Patch v2 09/42] btrfs: refactor how we finish ordered extent io for endio functions Qu Wenruo
2021-05-13 23:11 ` David Sterba
2021-04-27 23:03 ` [Patch v2 10/42] btrfs: update the comments in btrfs_invalidatepage() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 11/42] btrfs: introduce btrfs_lookup_first_ordered_range() Qu Wenruo
2021-05-13 23:13 ` David Sterba
2021-04-27 23:03 ` [Patch v2 12/42] btrfs: refactor btrfs_invalidatepage() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 13/42] btrfs: rename PagePrivate2 to PageOrdered inside btrfs Qu Wenruo
2021-04-27 23:03 ` [Patch v2 14/42] btrfs: pass bytenr directly to __process_pages_contig() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 15/42] btrfs: refactor the page status update into process_one_page() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 16/42] btrfs: provide btrfs_page_clamp_*() helpers Qu Wenruo
2021-04-27 23:03 ` [Patch v2 17/42] btrfs: only require sector size alignment for end_bio_extent_writepage() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 18/42] btrfs: make btrfs_dirty_pages() to be subpage compatible Qu Wenruo
2021-04-27 23:03 ` [Patch v2 19/42] btrfs: make __process_pages_contig() to handle subpage dirty/error/writeback status Qu Wenruo
2021-04-27 23:03 ` [Patch v2 20/42] btrfs: make end_bio_extent_writepage() to be subpage compatible Qu Wenruo
2021-04-27 23:03 ` [Patch v2 21/42] btrfs: make process_one_page() to handle subpage locking Qu Wenruo
2021-04-27 23:03 ` [Patch v2 22/42] btrfs: introduce helpers for subpage ordered status Qu Wenruo
2021-04-27 23:03 ` [Patch v2 23/42] btrfs: make page Ordered bit to be subpage compatible Qu Wenruo
2021-04-27 23:03 ` [Patch v2 24/42] btrfs: update locked page dirty/writeback/error bits in __process_pages_contig Qu Wenruo
2021-04-27 23:03 ` [Patch v2 25/42] btrfs: prevent extent_clear_unlock_delalloc() to unlock page not locked by __process_pages_contig() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 26/42] btrfs: make btrfs_set_range_writeback() subpage compatible Qu Wenruo
2021-04-27 23:03 ` [Patch v2 27/42] btrfs: make __extent_writepage_io() only submit dirty range for subpage Qu Wenruo
2021-04-27 23:03 ` [Patch v2 28/42] btrfs: make btrfs_truncate_block() to be subpage compatible Qu Wenruo
2021-04-27 23:03 ` [Patch v2 29/42] btrfs: make btrfs_page_mkwrite() " Qu Wenruo
2021-04-27 23:03 ` [Patch v2 30/42] btrfs: reflink: make copy_inline_to_page() " Qu Wenruo
2021-04-27 23:03 ` [Patch v2 31/42] btrfs: fix the filemap_range_has_page() call in btrfs_punch_hole_lock_range() Qu Wenruo
2021-04-27 23:03 ` [Patch v2 32/42] btrfs: don't clear page extent mapped if we're not invalidating the full page Qu Wenruo
2021-04-27 23:03 ` [Patch v2 33/42] btrfs: extract relocation page read and dirty part into its own function Qu Wenruo
2021-04-27 23:03 ` [Patch v2 34/42] btrfs: make relocate_one_page() to handle subpage case Qu Wenruo
2021-04-27 23:03 ` [Patch v2 35/42] btrfs: fix wild subpage writeback which does not have ordered extent Qu Wenruo
2021-04-27 23:03 ` [Patch v2 36/42] btrfs: disable inline extent creation for subpage Qu Wenruo
2021-05-04 4:28 ` Qu Wenruo
2021-04-27 23:03 ` [Patch v2 37/42] btrfs: skip validation for subpage read repair Qu Wenruo
2021-04-27 23:03 ` [Patch v2 38/42] btrfs: allow submit_extent_page() to do bio split for subpage Qu Wenruo
2021-04-27 23:03 ` [Patch v2 39/42] btrfs: reject raid5/6 fs " Qu Wenruo
2021-04-28 14:22 ` Neal Gompa
2021-04-28 23:11 ` Qu Wenruo
2021-05-12 22:04 ` David Sterba
2021-04-27 23:03 ` [Patch v2 40/42] btrfs: fix a crash caused by race between prepare_pages() and btrfs_releasepage() Qu Wenruo
2021-04-28 10:56 ` Filipe Manana
2021-04-27 23:03 ` [Patch v2 41/42] btrfs: fix the use-after-free bug in writeback subpage helper Qu Wenruo
2021-05-06 23:46 ` Qu Wenruo
2021-05-07 4:57 ` Ritesh Harjani
2021-05-07 5:14 ` Qu Wenruo
2021-05-10 8:38 ` Qu Wenruo
2021-05-10 12:29 ` Ritesh Harjani
2021-05-10 13:10 ` Qu Wenruo
2021-05-11 10:48 ` Ritesh Harjani
2021-05-11 11:15 ` Qu Wenruo
2021-05-12 1:49 ` Qu Wenruo
2021-05-12 7:09 ` Ritesh Harjani
2021-05-13 16:33 ` Ritesh Harjani
2021-05-13 21:36 ` Ritesh Harjani
2021-05-13 23:41 ` Qu Wenruo
2021-05-14 15:08 ` Ritesh Harjani
2021-05-14 17:53 ` Ritesh Harjani
2021-05-14 22:22 ` Qu Wenruo
2021-05-15 9:59 ` Ritesh Harjani
2021-05-15 10:15 ` Qu Wenruo
2021-05-25 4:43 ` Ritesh Harjani
2021-05-25 5:52 ` Qu Wenruo
2021-05-25 6:14 ` Qu Wenruo
2021-05-25 9:23 ` Ritesh Harjani
2021-05-25 9:45 ` Qu Wenruo
2021-05-25 9:49 ` Qu Wenruo
2021-05-25 10:20 ` Ritesh Harjani
2021-05-25 11:41 ` Qu Wenruo
2021-05-25 13:02 ` Ritesh Harjani
2021-05-26 5:29 ` Ritesh Harjani
2021-05-26 5:58 ` Qu Wenruo
2021-05-26 13:45 ` Ritesh Harjani
2021-05-28 8:26 ` Qu Wenruo
2021-05-28 8:59 ` Ritesh Harjani
2021-05-28 10:25 ` Qu Wenruo
2021-05-30 1:50 ` Qu Wenruo
2021-04-27 23:03 ` [Patch v2 42/42] btrfs: allow read-write for 4K sectorsize on 64K page size systems Qu Wenruo
2021-05-12 22:18 ` [Patch v2 00/42] btrfs: add data write support for subpage David Sterba
2021-05-12 23:48 ` Qu Wenruo
2021-05-13 2:21 ` Qu Wenruo
2021-05-13 22:54 ` David Sterba
2021-05-14 1:41 ` Qu Wenruo
2021-05-14 2:26 ` riteshh
2021-05-14 10:28 ` riteshh
2021-05-14 11:28 ` David Sterba
2021-05-14 14:38 ` riteshh
2021-05-14 11:30 ` David Sterba
2021-05-14 22:25 ` David Sterba
2021-05-14 22:45 ` Qu Wenruo
2021-05-14 23:05 ` David Sterba
2021-05-14 23:17 ` Qu Wenruo
2021-05-17 13:22 ` David Sterba
2021-05-17 23:20 ` Qu Wenruo
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