Re: [PATCH v2 07/12] mm: Add an 'end' parameter to pagevec_lookup_entries

From: Jan Kara
Date: Tue Sep 29 2020 - 05:02:47 EST


On Mon 14-09-20 14:00:37, Matthew Wilcox (Oracle) wrote:
> Simplifies the callers and uses the existing functionality
> in find_get_entries(). We can also drop the final argument of
> truncate_exceptional_pvec_entries() and simplify the logic in that
> function.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> include/linux/pagevec.h | 5 ++---
> mm/swap.c | 8 ++++----
> mm/truncate.c | 41 ++++++++++-------------------------------
> 3 files changed, 16 insertions(+), 38 deletions(-)
>
> diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
> index 081d934eda64..4b245592262c 100644
> --- a/include/linux/pagevec.h
> +++ b/include/linux/pagevec.h
> @@ -26,9 +26,8 @@ struct pagevec {
> void __pagevec_release(struct pagevec *pvec);
> void __pagevec_lru_add(struct pagevec *pvec);
> unsigned pagevec_lookup_entries(struct pagevec *pvec,
> - struct address_space *mapping,
> - pgoff_t start, unsigned nr_entries,
> - pgoff_t *indices);
> + struct address_space *mapping, pgoff_t start, pgoff_t end,
> + unsigned nr_entries, pgoff_t *indices);
> void pagevec_remove_exceptionals(struct pagevec *pvec);
> unsigned pagevec_lookup_range(struct pagevec *pvec,
> struct address_space *mapping,
> diff --git a/mm/swap.c b/mm/swap.c
> index fcf6ccb94b09..b6e56a84b466 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -1036,6 +1036,7 @@ void __pagevec_lru_add(struct pagevec *pvec)
> * @pvec: Where the resulting entries are placed
> * @mapping: The address_space to search
> * @start: The starting entry index
> + * @end: The highest index to return (inclusive).
> * @nr_entries: The maximum number of pages
> * @indices: The cache indices corresponding to the entries in @pvec
> *
> @@ -1056,11 +1057,10 @@ void __pagevec_lru_add(struct pagevec *pvec)
> * found.
> */
> unsigned pagevec_lookup_entries(struct pagevec *pvec,
> - struct address_space *mapping,
> - pgoff_t start, unsigned nr_entries,
> - pgoff_t *indices)
> + struct address_space *mapping, pgoff_t start, pgoff_t end,
> + unsigned nr_entries, pgoff_t *indices)
> {
> - pvec->nr = find_get_entries(mapping, start, ULONG_MAX, nr_entries,
> + pvec->nr = find_get_entries(mapping, start, end, nr_entries,
> pvec->pages, indices);
> return pagevec_count(pvec);
> }
> diff --git a/mm/truncate.c b/mm/truncate.c
> index 5dbe0c77b5ac..69ea72e7fc1c 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -57,11 +57,10 @@ static void clear_shadow_entry(struct address_space *mapping, pgoff_t index,
> * exceptional entries similar to what pagevec_remove_exceptionals does.
> */
> static void truncate_exceptional_pvec_entries(struct address_space *mapping,
> - struct pagevec *pvec, pgoff_t *indices,
> - pgoff_t end)
> + struct pagevec *pvec, pgoff_t *indices)
> {
> int i, j;
> - bool dax, lock;
> + bool dax;
>
> /* Handled by shmem itself */
> if (shmem_mapping(mapping))
> @@ -75,8 +74,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping,
> return;
>
> dax = dax_mapping(mapping);
> - lock = !dax && indices[j] < end;
> - if (lock)
> + if (!dax)
> xa_lock_irq(&mapping->i_pages);
>
> for (i = j; i < pagevec_count(pvec); i++) {
> @@ -88,9 +86,6 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping,
> continue;
> }
>
> - if (index >= end)
> - continue;
> -
> if (unlikely(dax)) {
> dax_delete_mapping_entry(mapping, index);
> continue;
> @@ -99,7 +94,7 @@ static void truncate_exceptional_pvec_entries(struct address_space *mapping,
> __clear_shadow_entry(mapping, index, page);
> }
>
> - if (lock)
> + if (!dax)
> xa_unlock_irq(&mapping->i_pages);
> pvec->nr = j;
> }
> @@ -329,7 +324,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
> while (index < end && find_lock_entries(mapping, index, end - 1,
> &pvec, indices)) {
> index = indices[pagevec_count(&pvec) - 1] + 1;
> - truncate_exceptional_pvec_entries(mapping, &pvec, indices, end);
> + truncate_exceptional_pvec_entries(mapping, &pvec, indices);
> for (i = 0; i < pagevec_count(&pvec); i++)
> truncate_cleanup_page(mapping, pvec.pages[i]);
> delete_from_page_cache_batch(mapping, &pvec);
> @@ -381,8 +376,8 @@ void truncate_inode_pages_range(struct address_space *mapping,
> index = start;
> for ( ; ; ) {
> cond_resched();
> - if (!pagevec_lookup_entries(&pvec, mapping, index,
> - min(end - index, (pgoff_t)PAGEVEC_SIZE), indices)) {
> + if (!pagevec_lookup_entries(&pvec, mapping, index, end - 1,
> + PAGEVEC_SIZE, indices)) {
> /* If all gone from start onwards, we're done */
> if (index == start)
> break;
> @@ -390,23 +385,12 @@ void truncate_inode_pages_range(struct address_space *mapping,
> index = start;
> continue;
> }
> - if (index == start && indices[0] >= end) {
> - /* All gone out of hole to be punched, we're done */
> - pagevec_remove_exceptionals(&pvec);
> - pagevec_release(&pvec);
> - break;
> - }
>
> for (i = 0; i < pagevec_count(&pvec); i++) {
> struct page *page = pvec.pages[i];
>
> /* We rely upon deletion not changing page->index */
> index = indices[i];
> - if (index >= end) {
> - /* Restart punch to make sure all gone */
> - index = start - 1;
> - break;
> - }
>
> if (xa_is_value(page))
> continue;
> @@ -417,7 +401,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
> truncate_inode_page(mapping, page);
> unlock_page(page);
> }
> - truncate_exceptional_pvec_entries(mapping, &pvec, indices, end);
> + truncate_exceptional_pvec_entries(mapping, &pvec, indices);
> pagevec_release(&pvec);
> index++;
> }
> @@ -528,8 +512,6 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping,
>
> /* We rely upon deletion not changing page->index */
> index = indices[i];
> - if (index > end)
> - break;
>
> if (xa_is_value(page)) {
> invalidate_exceptional_entry(mapping, index,
> @@ -629,16 +611,13 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
>
> pagevec_init(&pvec);
> index = start;
> - while (index <= end && pagevec_lookup_entries(&pvec, mapping, index,
> - min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1,
> - indices)) {
> + while (pagevec_lookup_entries(&pvec, mapping, index, end,
> + PAGEVEC_SIZE, indices)) {
> for (i = 0; i < pagevec_count(&pvec); i++) {
> struct page *page = pvec.pages[i];
>
> /* We rely upon deletion not changing page->index */
> index = indices[i];
> - if (index > end)
> - break;
>
> if (xa_is_value(page)) {
> if (!invalidate_exceptional_entry2(mapping,
> --
> 2.28.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR