On 2021/3/16 上午2:51, David Sterba wrote:
On Mon, Mar 15, 2021 at 04:25:32PM +0800, Qu Wenruo wrote:
On 2021/3/15 下午3:55, Johannes Thumshirn wrote:
On 15/03/2021 06:40, Qu Wenruo wrote:
The difference against find_extent_buffer_nospinlock() is:
- Also handles regular sectorsize == PAGE_SIZE case
- No extent buffer refs increase/decrease
As extent buffer under IO must has non-zero refs.
Can these be merged into a single function? The sectorsie == PAGE_SIZE case
won't do anything for find_extent_buffer_nospinlock() and the
atomic_inc_not_zero(&eb->refs) can be hidden behind a 'if (write)' check.
That would make the eb refs change too inconsistent.
But I get your point.
How about calling find_extent_buffer_nospinlock() and then dec the refs
manually?
Is this equivalent to this patch? Ie. the atomic_inc_not_zero in
find_extent_buffer_nospinlock happens inside the RCU section, while what
you suggest looks like
find_extent_buffer_nospinlock()
rcu_lock
radix_lookup
rcu_unlock
atomic_inc_not_zero()
No, I mean just call find_extent_buffer_nospinlock() directly.
Then manually call atomic_dec() on the returned eb.
Thanks,
Qu
