On Wed, Aug 19, 2020 at 04:05:51PM +0100, Matthew Wilcox (Oracle) wrote:
> This simplifies the callers and leads to a more efficient implementation
> since the XArray has this functionality already.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> include/linux/pagemap.h | 4 ++--
> mm/filemap.c | 9 +++++----
> mm/shmem.c | 10 ++++------
> mm/swap.c | 2 +-
> 4 files changed, 12 insertions(+), 13 deletions(-)
>
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 7de11dcd534d..3f0dc8d00f2a 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -387,8 +387,8 @@ static inline struct page *find_subpage(struct page *head, pgoff_t index)
> struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
> struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
> unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
> - unsigned int nr_entries, struct page **entries,
> - pgoff_t *indices);
> + pgoff_t end, unsigned int nr_entries, struct page **entries,
> + pgoff_t *indices);
> unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
> pgoff_t end, unsigned int nr_pages,
> struct page **pages);
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 1aaea26556cc..159cf3d6f1ae 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -1742,6 +1742,7 @@ EXPORT_SYMBOL(pagecache_get_page);
> * find_get_entries - gang pagecache lookup
> * @mapping: The address_space to search
> * @start: The starting page cache index
> + * @end: The highest page cache index to return.
Maybe add here whether 'end' is inclusive or exclusive?
> * @nr_entries: The maximum number of entries
> * @entries: Where the resulting entries are placed
> * @indices: The cache indices corresponding to the entries in @entries
> @@ -1765,9 +1766,9 @@ EXPORT_SYMBOL(pagecache_get_page);
> *
> * Return: the number of pages and shadow entries which were found.
> */
> -unsigned find_get_entries(struct address_space *mapping,
> - pgoff_t start, unsigned int nr_entries,
> - struct page **entries, pgoff_t *indices)
> +unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
> + pgoff_t end, unsigned int nr_entries, struct page **entries,
> + pgoff_t *indices)
> {
> XA_STATE(xas, &mapping->i_pages, start);
> struct page *page;
> @@ -1777,7 +1778,7 @@ unsigned find_get_entries(struct address_space *mapping,
> return 0;
>
> rcu_read_lock();
> - xas_for_each(&xas, page, ULONG_MAX) {
> + xas_for_each(&xas, page, end) {
> if (xas_retry(&xas, page))
> continue;
> /*
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 0f9f149f4b5e..abdbe61a1aa7 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -906,9 +906,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
> pagevec_init(&pvec);
> index = start;
> while (index < end) {
> - pvec.nr = find_get_entries(mapping, index,
> - min(end - index, (pgoff_t)PAGEVEC_SIZE),
> - pvec.pages, indices);
> + pvec.nr = find_get_entries(mapping, index, end - 1,
> + PAGEVEC_SIZE, pvec.pages, indices);
> if (!pvec.nr)
> break;
> for (i = 0; i < pagevec_count(&pvec); i++) {
> @@ -977,9 +976,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
> while (index < end) {
> cond_resched();
>
> - pvec.nr = find_get_entries(mapping, index,
> - min(end - index, (pgoff_t)PAGEVEC_SIZE),
> - pvec.pages, indices);
> + pvec.nr = find_get_entries(mapping, index, end - 1,
> + PAGEVEC_SIZE, pvec.pages, indices);
> if (!pvec.nr) {
> /* If all gone or hole-punch or unfalloc, we're done */
> if (index == start || end != -1)
> diff --git a/mm/swap.c b/mm/swap.c
> index d16d65d9b4e0..fcf6ccb94b09 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -1060,7 +1060,7 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec,
> pgoff_t start, unsigned nr_entries,
> pgoff_t *indices)
> {
> - pvec->nr = find_get_entries(mapping, start, nr_entries,
> + pvec->nr = find_get_entries(mapping, start, ULONG_MAX, nr_entries,
> pvec->pages, indices);
> return pagevec_count(pvec);
> }
> --
> 2.28.0
>
>
--
Sincerely yours,
Mike.
