From: Nikolay Borisov <nborisov@suse.com>
To: Qu Wenruo <wqu@suse.com>, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 17/32] btrfs: extent_io: don't allow tree block to cross page boundary for subpage support
Date: Fri, 6 Nov 2020 16:04:03 +0200 [thread overview]
Message-ID: <d45d198c-d7bd-a066-0fb6-686b77c8694e@suse.com> (raw)
In-Reply-To: <981350a6-77f9-6419-7a2e-22110364a55b@suse.com>
On 6.11.20 г. 15:25 ч., Qu Wenruo wrote:
>
>
> On 2020/11/6 下午7:54, Nikolay Borisov wrote:
>>
>>
>> On 3.11.20 г. 15:30 ч., Qu Wenruo wrote:
>>> As a preparation for subpage sector size support (allowing filesystem
>>> with sector size smaller than page size to be mounted) if the sector
>>> size is smaller than page size, we don't allow tree block to be read if
>>> it crosses 64K(*) boundary.
>>>
>>> The 64K is selected because:
>>> - We are only going to support 64K page size for subpage for now
>>> - 64K is also the max node size btrfs supports
>>>
>>> This ensures that, tree blocks are always contained in one page for a
>>> system with 64K page size, which can greatly simplify the handling.
>>>
>>> Or we need to do complex multi-page handling for tree blocks.
>>>
>>> Currently the only way to create such tree blocks crossing 64K boundary
>>> is by btrfs-convert, which will get fixed soon and doesn't get
>>> wide-spread usage.
>>
>> So filesystems with subpage blocksize which have been created as a
>> result of a convert operation would eventually fail to read some block
>> am I correct in my understanding? If that is the case then can't we
>> simply land subpage support in userspace tools _after_ the convert has
>> been fixed and turn this check into an assert?
>
> My bad, after I checked the convert code, at least from 2016 that all
> free space convert can utilized is already 64K aligned.
>
> So there isn't much thing to be done in convert already.
So remove the bit about convert and does that mean this code should
really be turned into an assert?
>
> Thanks,
> Qu
>
>>
>>
>>>
>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>> ---
>>> fs/btrfs/extent_io.c | 7 +++++++
>>> 1 file changed, 7 insertions(+)
>>>
>>> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
>>> index 30768e49cf47..30bbaeaa129a 100644
>>> --- a/fs/btrfs/extent_io.c
>>> +++ b/fs/btrfs/extent_io.c
>>> @@ -5261,6 +5261,13 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
>>> btrfs_err(fs_info, "bad tree block start %llu", start);
>>> return ERR_PTR(-EINVAL);
>>> }
>>> + if (btrfs_is_subpage(fs_info) && round_down(start, PAGE_SIZE) !=
>>> + round_down(start + len - 1, PAGE_SIZE)) {
>>> + btrfs_err(fs_info,
>>> + "tree block crosses page boundary, start %llu nodesize %lu",
>>> + start, len);
>>> + return ERR_PTR(-EINVAL);
>>> + }
>>>
>>> eb = find_extent_buffer(fs_info, start);
>>> if (eb)
>>>
>>
>
next prev parent reply other threads:[~2020-11-06 14:04 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 13:30 [PATCH 00/32] btrfs: preparation patches for subpage support Qu Wenruo
2020-11-03 13:30 ` [PATCH 01/32] btrfs: extent_io: remove the extent_start/extent_len for end_bio_extent_readpage() Qu Wenruo
2020-11-05 9:46 ` Nikolay Borisov
2020-11-05 10:15 ` Qu Wenruo
2020-11-05 10:32 ` Nikolay Borisov
2020-11-06 2:01 ` Qu Wenruo
2020-11-06 7:19 ` Qu Wenruo
2020-11-05 19:40 ` Josef Bacik
2020-11-06 1:52 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 02/32] btrfs: extent_io: integrate page status update into endio_readpage_release_extent() Qu Wenruo
2020-11-05 10:26 ` Nikolay Borisov
2020-11-05 11:15 ` Qu Wenruo
2020-11-05 10:35 ` Nikolay Borisov
2020-11-05 11:25 ` Qu Wenruo
2020-11-05 19:34 ` Josef Bacik
2020-11-03 13:30 ` [PATCH 03/32] btrfs: extent_io: add lockdep_assert_held() for attach_extent_buffer_page() Qu Wenruo
2020-11-03 13:30 ` [PATCH 04/32] btrfs: extent_io: extract the btree page submission code into its own helper function Qu Wenruo
2020-11-05 10:47 ` Nikolay Borisov
2020-11-06 18:11 ` David Sterba
2020-11-03 13:30 ` [PATCH 05/32] btrfs: extent-io-tests: remove invalid tests Qu Wenruo
2020-11-03 13:30 ` [PATCH 06/32] btrfs: extent_io: calculate inline extent buffer page size based on page size Qu Wenruo
2020-11-05 12:54 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 07/32] btrfs: extent_io: make btrfs_fs_info::buffer_radix to take sector size devided values Qu Wenruo
2020-11-03 13:30 ` [PATCH 08/32] btrfs: extent_io: sink less common parameters for __set_extent_bit() Qu Wenruo
2020-11-05 13:35 ` Nikolay Borisov
2020-11-05 13:55 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 09/32] btrfs: extent_io: sink less common parameters for __clear_extent_bit() Qu Wenruo
2020-11-03 13:30 ` [PATCH 10/32] btrfs: disk_io: grab fs_info from extent_buffer::fs_info directly for btrfs_mark_buffer_dirty() Qu Wenruo
2020-11-05 13:45 ` Nikolay Borisov
2020-11-05 13:49 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 11/32] btrfs: disk-io: make csum_tree_block() handle sectorsize smaller than page size Qu Wenruo
2020-11-06 18:58 ` David Sterba
2020-11-07 0:04 ` Qu Wenruo
2020-11-10 14:33 ` David Sterba
2020-11-11 0:08 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 12/32] btrfs: disk-io: extract the extent buffer verification from btrfs_validate_metadata_buffer() Qu Wenruo
2020-11-05 13:57 ` Nikolay Borisov
2020-11-06 19:03 ` David Sterba
2020-11-09 6:44 ` Qu Wenruo
2020-11-10 14:37 ` David Sterba
2020-11-03 13:30 ` [PATCH 13/32] btrfs: disk-io: accept bvec directly for csum_dirty_buffer() Qu Wenruo
2020-11-05 14:13 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 14/32] btrfs: inode: make btrfs_readpage_end_io_hook() follow sector size Qu Wenruo
2020-11-05 14:28 ` Nikolay Borisov
2020-11-06 19:16 ` David Sterba
2020-11-06 19:20 ` David Sterba
2020-11-06 19:28 ` David Sterba
2020-11-03 13:30 ` [PATCH 15/32] btrfs: introduce a helper to determine if the sectorsize is smaller than PAGE_SIZE Qu Wenruo
2020-11-05 15:01 ` Nikolay Borisov
2020-11-05 22:52 ` Qu Wenruo
2020-11-06 17:28 ` David Sterba
2020-11-07 0:00 ` Qu Wenruo
2020-11-10 14:53 ` David Sterba
2020-11-11 1:34 ` Qu Wenruo
2020-11-11 2:21 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 16/32] btrfs: extent_io: allow find_first_extent_bit() to find a range with exact bits match Qu Wenruo
2020-11-05 15:03 ` Nikolay Borisov
2020-11-05 22:55 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 17/32] btrfs: extent_io: don't allow tree block to cross page boundary for subpage support Qu Wenruo
2020-11-06 11:54 ` Nikolay Borisov
2020-11-06 12:03 ` Nikolay Borisov
2020-11-06 13:25 ` Qu Wenruo
2020-11-06 14:04 ` Nikolay Borisov [this message]
2020-11-06 23:56 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 18/32] btrfs: extent_io: update num_extent_pages() to support subpage sized extent buffer Qu Wenruo
2020-11-06 12:09 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 19/32] btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors Qu Wenruo
2020-11-06 12:51 ` Nikolay Borisov
2020-11-09 5:49 ` Qu Wenruo
2020-11-03 13:30 ` [PATCH 20/32] btrfs: disk-io: only clear EXTENT_LOCK bit for extent_invalidatepage() Qu Wenruo
2020-11-06 13:17 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 21/32] btrfs: extent-io: make type of extent_state::state to be at least 32 bits Qu Wenruo
2020-11-06 13:38 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 22/32] btrfs: file-item: use nodesize to determine whether we need readahead for btrfs_lookup_bio_sums() Qu Wenruo
2020-11-06 13:55 ` Nikolay Borisov
2020-11-03 13:30 ` [PATCH 23/32] btrfs: file-item: remove the btrfs_find_ordered_sum() call in btrfs_lookup_bio_sums() Qu Wenruo
2020-11-06 14:28 ` Nikolay Borisov
2020-11-03 13:31 ` [PATCH 24/32] btrfs: file-item: refactor btrfs_lookup_bio_sums() to handle out-of-order bvecs Qu Wenruo
2020-11-06 15:22 ` Nikolay Borisov
2020-11-03 13:31 ` [PATCH 25/32] btrfs: scrub: distinguish scrub_page from regular page Qu Wenruo
2020-11-03 13:31 ` [PATCH 26/32] btrfs: scrub: remove the @force parameter of scrub_pages() Qu Wenruo
2020-11-03 13:31 ` [PATCH 27/32] btrfs: scrub: use flexible array for scrub_page::csums Qu Wenruo
2020-11-09 17:44 ` David Sterba
2020-11-10 0:53 ` Qu Wenruo
2020-11-10 14:22 ` David Sterba
2020-11-03 13:31 ` [PATCH 28/32] btrfs: scrub: refactor scrub_find_csum() Qu Wenruo
2020-11-03 13:31 ` [PATCH 29/32] btrfs: scrub: introduce scrub_page::page_len for subpage support Qu Wenruo
2020-11-09 18:17 ` David Sterba
2020-11-10 0:54 ` Qu Wenruo
2020-11-09 18:25 ` David Sterba
2020-11-10 0:56 ` Qu Wenruo
2020-11-10 14:27 ` David Sterba
2020-11-03 13:31 ` [PATCH 30/32] btrfs: scrub: always allocate one full page for one sector for RAID56 Qu Wenruo
2020-11-03 13:31 ` [PATCH 31/32] btrfs: scrub: support subpage tree block scrub Qu Wenruo
2020-11-09 18:31 ` David Sterba
2020-11-03 13:31 ` [PATCH 32/32] btrfs: scrub: support subpage data scrub Qu Wenruo
2020-11-05 19:28 ` [PATCH 00/32] btrfs: preparation patches for subpage support Josef Bacik
2020-11-06 0:02 ` Qu Wenruo
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