From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Matthew Wilcox To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , Jan Kara , Jeff Layton , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues , Nicholas Piggin , Ryusuke Konishi , linux-nilfs@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net Subject: [PATCH v14 51/74] shmem: Convert shmem_alloc_hugepage to XArray Date: Sat, 16 Jun 2018 19:00:29 -0700 Message-Id: <20180617020052.4759-52-willy@infradead.org> In-Reply-To: <20180617020052.4759-1-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Sender: owner-linux-mm@kvack.org List-ID: xa_find() is a slightly easier API to use than radix_tree_gang_lookup_slot() because it contains its own RCU locking. This commit removes the last user of radix_tree_gang_lookup_slot() so remove the function too. Signed-off-by: Matthew Wilcox --- include/linux/radix-tree.h | 6 +----- lib/radix-tree.c | 44 +------------------------------------- mm/shmem.c | 14 ++++-------- 3 files changed, 6 insertions(+), 58 deletions(-) diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h index eefa0b099dd5..081e68b4376b 100644 --- a/include/linux/radix-tree.h +++ b/include/linux/radix-tree.h @@ -147,12 +147,11 @@ static inline unsigned int iter_shift(const struct radix_tree_iter *iter) * radix_tree_lookup_slot * radix_tree_tag_get * radix_tree_gang_lookup - * radix_tree_gang_lookup_slot * radix_tree_gang_lookup_tag * radix_tree_gang_lookup_tag_slot * radix_tree_tagged * - * The first 8 functions are able to be called locklessly, using RCU. The + * The first 7 functions are able to be called locklessly, using RCU. The * caller must ensure calls to these functions are made within rcu_read_lock() * regions. Other readers (lock-free or otherwise) and modifications may be * running concurrently. @@ -263,9 +262,6 @@ void radix_tree_clear_tags(struct radix_tree_root *, struct radix_tree_node *, unsigned int radix_tree_gang_lookup(const struct radix_tree_root *, void **results, unsigned long first_index, unsigned int max_items); -unsigned int radix_tree_gang_lookup_slot(const struct radix_tree_root *, - void __rcu ***results, unsigned long *indices, - unsigned long first_index, unsigned int max_items); int radix_tree_preload(gfp_t gfp_mask); int radix_tree_maybe_preload(gfp_t gfp_mask); int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order); diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 5c8a262f506c..d0f44ea96945 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1138,7 +1138,7 @@ void __radix_tree_replace(struct radix_tree_root *root, * @slot: pointer to slot * @item: new item to store in the slot. * - * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(), + * For use with radix_tree_lookup_slot() and * radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked * across slot lookup and replacement. * @@ -1772,48 +1772,6 @@ radix_tree_gang_lookup(const struct radix_tree_root *root, void **results, } EXPORT_SYMBOL(radix_tree_gang_lookup); -/** - * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree - * @root: radix tree root - * @results: where the results of the lookup are placed - * @indices: where their indices should be placed (but usually NULL) - * @first_index: start the lookup from this key - * @max_items: place up to this many items at *results - * - * Performs an index-ascending scan of the tree for present items. Places - * their slots at *@results and returns the number of items which were - * placed at *@results. - * - * The implementation is naive. - * - * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must - * be dereferenced with radix_tree_deref_slot, and if using only RCU - * protection, radix_tree_deref_slot may fail requiring a retry. - */ -unsigned int -radix_tree_gang_lookup_slot(const struct radix_tree_root *root, - void __rcu ***results, unsigned long *indices, - unsigned long first_index, unsigned int max_items) -{ - struct radix_tree_iter iter; - void __rcu **slot; - unsigned int ret = 0; - - if (unlikely(!max_items)) - return 0; - - radix_tree_for_each_slot(slot, root, &iter, first_index) { - results[ret] = slot; - if (indices) - indices[ret] = iter.index; - if (++ret == max_items) - break; - } - - return ret; -} -EXPORT_SYMBOL(radix_tree_gang_lookup_slot); - /** * radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree * based on a tag diff --git a/mm/shmem.c b/mm/shmem.c index 8e702b6d84a5..09452ca79220 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1434,23 +1434,17 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, struct shmem_inode_info *info, pgoff_t index) { struct vm_area_struct pvma; - struct inode *inode = &info->vfs_inode; - struct address_space *mapping = inode->i_mapping; - pgoff_t idx, hindex; - void __rcu **results; + struct address_space *mapping = info->vfs_inode.i_mapping; + pgoff_t hindex; struct page *page; if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) return NULL; hindex = round_down(index, HPAGE_PMD_NR); - rcu_read_lock(); - if (radix_tree_gang_lookup_slot(&mapping->i_pages, &results, &idx, - hindex, 1) && idx < hindex + HPAGE_PMD_NR) { - rcu_read_unlock(); + if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1, + XA_PRESENT)) return NULL; - } - rcu_read_unlock(); shmem_pseudo_vma_init(&pvma, info, hindex); page = alloc_pages_vma(gfp | __GFP_COMP | __GFP_NORETRY | __GFP_NOWARN, -- 2.17.1