From: Nikolay Borisov <nborisov@suse.com>
To: Qu Wenruo <wqu@suse.com>, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH 04/17] btrfs: make btrfs_fs_info::buffer_radix to take sector size devided values
Date: Fri, 11 Sep 2020 13:11:54 +0300 [thread overview]
Message-ID: <cb58ceb4-1636-c717-7ac5-4a45d4d80314@suse.com> (raw)
In-Reply-To: <20200908075230.86856-5-wqu@suse.com>
On 8.09.20 г. 10:52 ч., Qu Wenruo wrote:
> For subpage size sector size support, one page can contain mutliple tree
> blocks, thus we can no longer use (eb->start >> PAGE_SHIFT) any more, or
> we can easily get extent buffer doesn't belongs to us.
>
> This patch will use (extent_buffer::start / sectorsize) as index for radix
> tree so that we can get correct extent buffer for subpage size support.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
That's fine, however now that we are moving towards sectorsize I wonder
if it would make more sense to fs_info->sector_bits which would be
log2(fs_info->sectorsize) and have expressions such as:
start >> fs_info->sector_bits. I * think* we can rely on the compiler
doing the right thing given fs_info->sectorsize is guaranteed to be a
power of 2 value.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> ---
> fs/btrfs/extent_io.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 6def411b2eba..5d969340275e 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -5142,7 +5142,7 @@ struct extent_buffer *find_extent_buffer(struct btrfs_fs_info *fs_info,
>
> rcu_read_lock();
> eb = radix_tree_lookup(&fs_info->buffer_radix,
> - start >> PAGE_SHIFT);
> + start / fs_info->sectorsize);
> if (eb && atomic_inc_not_zero(&eb->refs)) {
> rcu_read_unlock();
> /*
> @@ -5194,7 +5194,7 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
> }
> spin_lock(&fs_info->buffer_lock);
> ret = radix_tree_insert(&fs_info->buffer_radix,
> - start >> PAGE_SHIFT, eb);
> + start / fs_info->sectorsize, eb);
> spin_unlock(&fs_info->buffer_lock);
> radix_tree_preload_end();
> if (ret == -EEXIST) {
> @@ -5302,7 +5302,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
>
> spin_lock(&fs_info->buffer_lock);
> ret = radix_tree_insert(&fs_info->buffer_radix,
> - start >> PAGE_SHIFT, eb);
> + start / fs_info->sectorsize, eb);
> spin_unlock(&fs_info->buffer_lock);
> radix_tree_preload_end();
> if (ret == -EEXIST) {
> @@ -5358,7 +5358,7 @@ static int release_extent_buffer(struct extent_buffer *eb)
>
> spin_lock(&fs_info->buffer_lock);
> radix_tree_delete(&fs_info->buffer_radix,
> - eb->start >> PAGE_SHIFT);
> + eb->start / fs_info->sectorsize);
> spin_unlock(&fs_info->buffer_lock);
> } else {
> spin_unlock(&eb->refs_lock);
>
next prev parent reply other threads:[~2020-09-11 10:12 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-08 7:52 [PATCH 00/17] btrfs: add read-only support for subpage sector size Qu Wenruo
2020-09-08 7:52 ` [PATCH 01/17] btrfs: extent-io-tests: remove invalid tests Qu Wenruo
2020-09-09 12:26 ` Nikolay Borisov
2020-09-09 13:06 ` Qu Wenruo
2020-09-08 7:52 ` [PATCH 02/17] btrfs: calculate inline extent buffer page size based on page size Qu Wenruo
2020-09-11 9:56 ` Nikolay Borisov
2020-09-11 10:13 ` Qu Wenruo
2020-09-08 7:52 ` [PATCH 03/17] btrfs: remove the open-code to read disk-key Qu Wenruo
2020-09-11 10:07 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 04/17] btrfs: make btrfs_fs_info::buffer_radix to take sector size devided values Qu Wenruo
2020-09-11 10:11 ` Nikolay Borisov [this message]
2020-09-11 10:15 ` Qu Wenruo
2020-09-08 7:52 ` [PATCH 05/17] btrfs: don't allow tree block to cross page boundary for subpage support Qu Wenruo
2020-09-11 10:26 ` Nikolay Borisov
2020-09-11 11:36 ` Qu Wenruo
2020-09-11 12:08 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 06/17] btrfs: handle sectorsize < PAGE_SIZE case for extent buffer accessors Qu Wenruo
2020-09-08 7:52 ` [PATCH 07/17] btrfs: make csum_tree_block() handle sectorsize smaller than page size Qu Wenruo
2020-09-11 11:10 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 08/17] btrfs: refactor how we extract extent buffer from page for alloc_extent_buffer() Qu Wenruo
2020-09-11 11:14 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 09/17] btrfs: refactor btrfs_release_extent_buffer_pages() Qu Wenruo
2020-09-11 11:17 ` Nikolay Borisov
2020-09-11 11:39 ` Qu Wenruo
2020-09-08 7:52 ` [PATCH 10/17] btrfs: add assert_spin_locked() for attach_extent_buffer_page() Qu Wenruo
2020-09-11 11:22 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 11/17] btrfs: extract the extent buffer verification from btree_readpage_end_io_hook() Qu Wenruo
2020-09-11 13:00 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 12/17] btrfs: remove the unnecessary parameter @start and @len for check_data_csum() Qu Wenruo
2020-09-11 13:50 ` Nikolay Borisov
2020-09-08 7:52 ` [PATCH 13/17] btrfs: extent_io: only require sector size alignment for page read Qu Wenruo
2020-09-11 13:55 ` Nikolay Borisov
2020-09-15 1:54 ` Qu Wenruo
2020-09-08 7:52 ` [PATCH 14/17] btrfs: make btrfs_readpage_end_io_hook() follow sector size Qu Wenruo
2020-09-09 17:34 ` Goldwyn Rodrigues
2020-09-10 0:05 ` Qu Wenruo
2020-09-10 14:26 ` Goldwyn Rodrigues
2020-09-08 7:52 ` [PATCH 15/17] btrfs: introduce subpage_eb_mapping for extent buffers Qu Wenruo
2020-09-08 10:22 ` kernel test robot
2020-09-08 14:24 ` Dan Carpenter
2020-09-08 7:52 ` [PATCH 16/17] btrfs: handle extent buffer verification proper for subpage size Qu Wenruo
2020-09-08 7:52 ` [PATCH 17/17] btrfs: allow RO mount of 4K sector size fs on 64K page system Qu Wenruo
2020-09-08 8:03 ` [PATCH 00/17] btrfs: add read-only support for subpage sector size Qu Wenruo
2020-09-11 10:24 ` Qu Wenruo
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