From: Stefan Roesch <[email protected]>
To: Filipe Manana <[email protected]>
Cc: [email protected], [email protected],
[email protected], [email protected],
[email protected]
Subject: Re: [PATCH v2 06/12] btrfs: make btrfs_check_nocow_lock nowait compatible
Date: Thu, 8 Sep 2022 11:23:07 -0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAL3q7H6mJEK=T78DF6o=xYmZht=x0jPVgDw3eVoHOKLyxfvdOA@mail.gmail.com>
On 9/8/22 3:18 AM, Filipe Manana wrote:
> >
> On Thu, Sep 8, 2022 at 1:26 AM Stefan Roesch <[email protected]> wrote:
>>
>> From: Josef Bacik <[email protected]>
>>
>> Now all the helpers that btrfs_check_nocow_lock uses handle nowait, add
>> a nowait flag to btrfs_check_nocow_lock so it can be used by the write
>> path.
>>
>> Signed-off-by: Josef Bacik <[email protected]>
>> Signed-off-by: Stefan Roesch <[email protected]>
>> ---
>> fs/btrfs/ctree.h | 2 +-
>> fs/btrfs/file.c | 33 ++++++++++++++++++++++-----------
>> fs/btrfs/inode.c | 2 +-
>> 3 files changed, 24 insertions(+), 13 deletions(-)
>>
>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>> index 536bbc8551fc..06cb25f2d3bd 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -3482,7 +3482,7 @@ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
>> struct extent_state **cached, bool noreserve);
>> int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end);
>> int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
>> - size_t *write_bytes);
>> + size_t *write_bytes, bool nowait);
>> void btrfs_check_nocow_unlock(struct btrfs_inode *inode);
>>
>> /* tree-defrag.c */
>> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
>> index 0f257205c63d..cf19d381ead6 100644
>> --- a/fs/btrfs/file.c
>> +++ b/fs/btrfs/file.c
>> @@ -1481,7 +1481,7 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
>> * NOTE: Callers need to call btrfs_check_nocow_unlock() if we return > 0.
>> */
>> int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
>> - size_t *write_bytes)
>> + size_t *write_bytes, bool nowait)
>> {
>> struct btrfs_fs_info *fs_info = inode->root->fs_info;
>> struct btrfs_root *root = inode->root;
>> @@ -1500,16 +1500,21 @@ int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
>> fs_info->sectorsize) - 1;
>> num_bytes = lockend - lockstart + 1;
>>
>> - btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, NULL);
>> + if (nowait) {
>> + if (!btrfs_try_lock_ordered_range(inode, lockstart, lockend)) {
>> + btrfs_drew_write_unlock(&root->snapshot_lock);
>> + return -EAGAIN;
>> + }
>> + } else {
>> + btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, NULL);
>> + }
>> ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
>> - NULL, NULL, NULL, false, false);
>> - if (ret <= 0) {
>> - ret = 0;
>> + NULL, NULL, NULL, nowait, false);
>> + if (ret <= 0)
>> btrfs_drew_write_unlock(&root->snapshot_lock);
>> - } else {
>> + else
>> *write_bytes = min_t(size_t, *write_bytes ,
>> num_bytes - pos + lockstart);
>> - }
>> unlock_extent(&inode->io_tree, lockstart, lockend);
>>
>> return ret;
>> @@ -1666,16 +1671,22 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
>> &data_reserved, pos,
>> write_bytes, false);
>> if (ret < 0) {
>> + int tmp;
>> +
>> /*
>> * If we don't have to COW at the offset, reserve
>> * metadata only. write_bytes may get smaller than
>> * requested here.
>> */
>> - if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
>> - &write_bytes) > 0)
>> - only_release_metadata = true;
>> - else
>> + tmp = btrfs_check_nocow_lock(BTRFS_I(inode), pos,
>> + &write_bytes, false);
>> + if (tmp < 0)
>> + ret = tmp;
>> + if (tmp > 0)
>> + ret = 0;
>> + if (ret)
>
> A variable named tmp is not a great name, something like "can_nocow'
> would be a lot more clear.
>
I renamed the variable tmp to can_nocow.
> Thanks.
>
>
>> break;
>> + only_release_metadata = true;
>> }
>>
>> num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE);
>> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
>> index 36e755f73764..5426d4f4ac23 100644
>> --- a/fs/btrfs/inode.c
>> +++ b/fs/btrfs/inode.c
>> @@ -4884,7 +4884,7 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
>> ret = btrfs_check_data_free_space(inode, &data_reserved, block_start,
>> blocksize, false);
>> if (ret < 0) {
>> - if (btrfs_check_nocow_lock(inode, block_start, &write_bytes) > 0) {
>> + if (btrfs_check_nocow_lock(inode, block_start, &write_bytes, false) > 0) {
>> /* For nocow case, no need to reserve data space */
>> only_release_metadata = true;
>> } else {
>> --
>> 2.30.2
>>
next prev parent reply other threads:[~2022-09-08 18:23 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 0:26 [PATCH v2 00/12] io-uring/btrfs: support async buffered writes Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 01/12] mm: export balance_dirty_pages_ratelimited_flags() Stefan Roesch
2022-09-08 10:18 ` Filipe Manana
2022-09-08 0:26 ` [PATCH v2 02/12] btrfs: implement a nowait option for tree searches Stefan Roesch
2022-09-08 13:19 ` Josef Bacik
2022-09-08 18:05 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 03/12] btrfs: make can_nocow_extent nowait compatible Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 04/12] btrfs: add the ability to use NO_FLUSH for data reservations Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 05/12] btrfs: add btrfs_try_lock_ordered_range Stefan Roesch
2022-09-08 10:18 ` Filipe Manana
2022-09-08 18:12 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 06/12] btrfs: make btrfs_check_nocow_lock nowait compatible Stefan Roesch
2022-09-08 10:18 ` Filipe Manana
2022-09-08 18:23 ` Stefan Roesch [this message]
2022-09-08 0:26 ` [PATCH v2 07/12] btrfs: make prepare_pages " Stefan Roesch
2022-09-08 10:17 ` Filipe Manana
2022-09-08 18:33 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 08/12] btrfs: make lock_and_cleanup_extent_if_need " Stefan Roesch
2022-09-08 10:17 ` Filipe Manana
2022-09-08 18:38 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 09/12] btrfs: btrfs: plumb NOWAIT through the write path Stefan Roesch
2022-09-08 10:16 ` Filipe Manana
2022-09-08 18:44 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 10/12] btrfs: make balance_dirty_pages nowait compatible Stefan Roesch
2022-09-08 10:16 ` Filipe Manana
2022-09-08 18:48 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 11/12] btrfs: add assert to search functions Stefan Roesch
2022-09-08 10:15 ` Filipe Manana
2022-09-08 19:10 ` Stefan Roesch
2022-09-08 0:26 ` [PATCH v2 12/12] btrfs: enable nowait async buffered writes Stefan Roesch
2022-09-08 10:14 ` Filipe Manana
2022-09-08 19:14 ` Stefan Roesch
2022-09-08 10:14 ` [PATCH v2 00/12] io-uring/btrfs: support " Filipe Manana
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