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author | Matthew Wilcox <willy@infradead.org> | 2018-05-16 18:00:33 -0400 |
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committer | Matthew Wilcox <willy@infradead.org> | 2018-10-21 10:46:34 -0400 |
commit | 3ece58a270cd1e5026282abe778bd50db7a11d08 (patch) | |
tree | ed4feeec0489b4fa9e513e8817363944da48dd3d /mm/filemap.c | |
parent | fd1b3cee2a867868d39bb8cbcc4b00c36d07cc01 (diff) | |
download | linux-stable-3ece58a270cd1e5026282abe778bd50db7a11d08.tar.gz linux-stable-3ece58a270cd1e5026282abe778bd50db7a11d08.tar.bz2 linux-stable-3ece58a270cd1e5026282abe778bd50db7a11d08.zip |
page cache: Convert find_get_pages_contig to XArray
There's no direct replacement for radix_tree_for_each_contig()
in the XArray API as it's an unusual thing to do. Instead,
open-code a loop using xas_next(). This removes the only user of
radix_tree_for_each_contig() so delete the iterator from the API and
the test suite code for it.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'mm/filemap.c')
-rw-r--r-- | mm/filemap.c | 53 |
1 files changed, 22 insertions, 31 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index b72c39fe61c2..089b67598100 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1721,57 +1721,43 @@ out: unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index, unsigned int nr_pages, struct page **pages) { - struct radix_tree_iter iter; - void **slot; + XA_STATE(xas, &mapping->i_pages, index); + struct page *page; unsigned int ret = 0; if (unlikely(!nr_pages)) return 0; rcu_read_lock(); - radix_tree_for_each_contig(slot, &mapping->i_pages, &iter, index) { - struct page *head, *page; -repeat: - page = radix_tree_deref_slot(slot); - /* The hole, there no reason to continue */ - if (unlikely(!page)) - break; - - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) { - slot = radix_tree_iter_retry(&iter); - continue; - } - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Stop - * looking for contiguous pages. - */ + for (page = xas_load(&xas); page; page = xas_next(&xas)) { + struct page *head; + if (xas_retry(&xas, page)) + continue; + /* + * If the entry has been swapped out, we can stop looking. + * No current caller is looking for DAX entries. + */ + if (xa_is_value(page)) break; - } head = compound_head(page); if (!page_cache_get_speculative(head)) - goto repeat; + goto retry; /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + if (compound_head(page) != head) + goto put_page; /* Has the page moved? */ - if (unlikely(page != *slot)) { - put_page(head); - goto repeat; - } + if (unlikely(page != xas_reload(&xas))) + goto put_page; /* * must check mapping and index after taking the ref. * otherwise we can get both false positives and false * negatives, which is just confusing to the caller. */ - if (page->mapping == NULL || page_to_pgoff(page) != iter.index) { + if (!page->mapping || page_to_pgoff(page) != xas.xa_index) { put_page(page); break; } @@ -1779,6 +1765,11 @@ repeat: pages[ret] = page; if (++ret == nr_pages) break; + continue; +put_page: + put_page(head); +retry: + xas_reset(&xas); } rcu_read_unlock(); return ret; |