From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
Jeff Layton <jlayton@redhat.com>,
Lukas Czerner <lczerner@redhat.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Christoph Hellwig <hch@lst.de>,
Goldwyn Rodrigues <rgoldwyn@suse.com>,
Nicholas Piggin <npiggin@gmail.com>,
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>,
linux-nilfs@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
Chao Yu <yuchao0@huawei.com>,
linux-f2fs-devel@lists.sourceforge.net
Subject: [PATCH v14 14/74] xarray: Extract entries from an XArray
Date: Sat, 16 Jun 2018 18:59:52 -0700 [thread overview]
Message-ID: <20180617020052.4759-15-willy@infradead.org> (raw)
In-Reply-To: <20180617020052.4759-1-willy@infradead.org>
The xa_extract function combines the functionality of
radix_tree_gang_lookup() and radix_tree_gang_lookup_tagged().
It extracts entries matching the specified filter into a normal array.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
include/linux/xarray.h | 2 ++
lib/xarray.c | 80 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+)
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index 0790b3b098f0..6f398732b664 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -227,6 +227,8 @@ void *xa_find(struct xarray *xa, unsigned long *index,
unsigned long max, xa_tag_t) __attribute__((nonnull(2)));
void *xa_find_after(struct xarray *xa, unsigned long *index,
unsigned long max, xa_tag_t) __attribute__((nonnull(2)));
+unsigned int xa_extract(struct xarray *, void **dst, unsigned long start,
+ unsigned long max, unsigned int n, xa_tag_t);
/**
* xa_init() - Initialise an empty XArray.
diff --git a/lib/xarray.c b/lib/xarray.c
index 8756ca22363e..1e15ead40d78 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1413,6 +1413,86 @@ void *xa_find_after(struct xarray *xa, unsigned long *indexp,
}
EXPORT_SYMBOL(xa_find_after);
+static unsigned int xas_extract_present(struct xa_state *xas, void **dst,
+ unsigned long max, unsigned int n)
+{
+ void *entry;
+ unsigned int i = 0;
+
+ rcu_read_lock();
+ xas_for_each(xas, entry, max) {
+ if (xas_retry(xas, entry))
+ continue;
+ dst[i++] = entry;
+ if (i == n)
+ break;
+ }
+ rcu_read_unlock();
+
+ return i;
+}
+
+static unsigned int xas_extract_tag(struct xa_state *xas, void **dst,
+ unsigned long max, unsigned int n, xa_tag_t tag)
+{
+ void *entry;
+ unsigned int i = 0;
+
+ rcu_read_lock();
+ xas_for_each_tagged(xas, entry, max, tag) {
+ if (xas_retry(xas, entry))
+ continue;
+ dst[i++] = entry;
+ if (i == n)
+ break;
+ }
+ rcu_read_unlock();
+
+ return i;
+}
+
+/**
+ * xa_extract() - Copy selected entries from the XArray into a normal array.
+ * @xa: The source XArray to copy from.
+ * @dst: The buffer to copy entries into.
+ * @start: The first index in the XArray eligible to be selected.
+ * @max: The last index in the XArray eligible to be selected.
+ * @n: The maximum number of entries to copy.
+ * @filter: Selection criterion.
+ *
+ * Copies up to @n entries that match @filter from the XArray. The
+ * copied entries will have indices between @start and @max, inclusive.
+ *
+ * The @filter may be an XArray tag value, in which case entries which are
+ * tagged with that tag will be copied. It may also be %XA_PRESENT, in
+ * which case non-NULL entries will be copied.
+ *
+ * The entries returned may not represent a snapshot of the XArray at a
+ * moment in time. For example, if another thread stores to index 5, then
+ * index 10, calling xa_extract() may return the old contents of index 5
+ * and the new contents of index 10. Indices not modified while this
+ * function is running will not be skipped.
+ *
+ * If you need stronger guarantees, holding the xa_lock across calls to this
+ * function will prevent concurrent modification.
+ *
+ * Context: Any context. Takes and releases the RCU lock.
+ * Return: The number of entries copied.
+ */
+unsigned int xa_extract(struct xarray *xa, void **dst, unsigned long start,
+ unsigned long max, unsigned int n, xa_tag_t filter)
+{
+ XA_STATE(xas, xa, start);
+
+ if (!n)
+ return 0;
+
+ if ((__force unsigned int)filter < XA_MAX_TAGS)
+ return xas_extract_tag(&xas, dst, max, n, filter);
+ return xas_extract_present(&xas, dst, max, n);
+}
+EXPORT_SYMBOL(xa_extract);
+
#ifdef XA_DEBUG
void xa_dump_node(const struct xa_node *node)
{
--
2.17.1
next prev parent reply other threads:[~2018-06-17 1:59 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-17 1:59 [PATCH v14 00/74] Convert page cache to XArray Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 01/74] Update email address Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 02/74] radix tree test suite: Enable ubsan Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 03/74] dax: Fix use of zero page Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 04/74] xarray: Replace exceptional entries Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 05/74] xarray: Change definition of sibling entries Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 06/74] xarray: Add definition of struct xarray Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 07/74] xarray: Define struct xa_node Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 08/74] xarray: Add documentation Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 09/74] xarray: Add XArray load operation Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 10/74] xarray: Add XArray tags Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 11/74] xarray: Add XArray unconditional store operations Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 12/74] xarray: Add XArray conditional " Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 13/74] xarray: Add XArray iterators Matthew Wilcox
2018-06-17 1:59 ` Matthew Wilcox [this message]
2018-06-17 1:59 ` [PATCH v14 15/74] xarray: Destroy an XArray Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 16/74] xarray: Step through " Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 17/74] xarray: Add xas_for_each_conflict Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 18/74] xarray: Add xas_create_range Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 19/74] xarray: Add MAINTAINERS entry Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 20/74] page cache: Rearrange address_space Matthew Wilcox
2018-06-17 1:59 ` [PATCH v14 21/74] page cache: Convert hole search to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 22/74] page cache: Add and replace pages using the XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 23/74] page cache: Convert page deletion to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 24/74] page cache: Convert find_get_entry " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 25/74] page cache: Convert find_get_entries " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 26/74] page cache: Convert find_get_pages_range " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 27/74] page cache: Convert find_get_pages_contig " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 28/74] page cache; Convert find_get_pages_range_tag " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 29/74] page cache: Convert find_get_entries_tag " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 30/74] page cache: Convert filemap_map_pages " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 31/74] radix tree test suite: Convert regression1 " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 32/74] page cache: Convert delete_batch " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 33/74] page cache: Remove stray radix comment Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 34/74] page cache: Convert filemap_range_has_page to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 35/74] mm: Convert page-writeback " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 36/74] mm: Convert workingset " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 37/74] mm: Convert truncate " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 38/74] mm: Convert add_to_swap_cache " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 39/74] mm: Convert delete_from_swap_cache " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 40/74] mm: Convert __do_page_cache_readahead " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 41/74] mm: Convert page migration " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 42/74] mm: Convert huge_memory " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 43/74] mm: Convert collapse_shmem " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 44/74] mm: Convert khugepaged_scan_shmem " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 45/74] mm: Convert is_page_cache_freeable " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 46/74] pagevec: Use xa_tag_t Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 47/74] shmem: Convert shmem_radix_tree_replace to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 48/74] shmem: Convert shmem_confirm_swap " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 49/74] shmem: Convert find_swap_entry " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 50/74] shmem: Convert shmem_add_to_page_cache " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 51/74] shmem: Convert shmem_alloc_hugepage " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 52/74] shmem: Convert shmem_free_swap " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 53/74] shmem: Convert shmem_partial_swap_usage " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 54/74] memfd: Convert memfd_wait_for_pins " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 55/74] memfd: Convert memfd_tag_pins " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 56/74] shmem: Comment fixups Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 57/74] btrfs: Convert page cache to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 58/74] fs: Convert buffer " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 59/74] fs: Convert writeback " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 60/74] nilfs2: Convert " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 61/74] f2fs: " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 62/74] dax: Rename some functions Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 63/74] dax: Hash on XArray instead of mapping Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 64/74] dax: Convert dax_insert_pfn_mkwrite to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 65/74] dax: Convert dax_layout_busy_page " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 66/74] dax: Convert __dax_invalidate_entry " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 67/74] dax: Convert dax writeback " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 68/74] dax: Convert dax_lock_page " Matthew Wilcox
2018-06-29 17:30 ` Ross Zwisler
2018-07-06 11:54 ` [PATCH] fs/dax: remove unused function Anders Roxell
2018-07-06 13:04 ` [PATCH v14 68/74] dax: Convert dax_lock_page to XArray Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 69/74] dax: Convert page fault handlers " Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 70/74] page cache: Finish XArray conversion Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 71/74] radix tree: Remove radix_tree_update_node_t Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 72/74] radix tree: Remove split/join code Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 73/74] radix tree: Remove radix_tree_maybe_preload_order Matthew Wilcox
2018-06-17 2:00 ` [PATCH v14 74/74] radix tree: Remove radix_tree_clear_tags Matthew Wilcox
2018-06-19 3:12 ` [PATCH v14 00/74] Convert page cache to XArray Ross Zwisler
2018-06-19 9:22 ` Matthew Wilcox
2018-06-19 16:40 ` Ross Zwisler
2018-06-19 17:16 ` Matthew Wilcox
2018-06-27 11:05 ` Matthew Wilcox
2018-06-27 19:44 ` Ross Zwisler
2018-06-28 8:39 ` Matthew Wilcox
2018-06-28 16:30 ` Ross Zwisler
2018-07-25 21:03 ` Matthew Wilcox
2018-07-25 21:12 ` Ross Zwisler
2018-07-27 17:20 ` Ross Zwisler
2018-07-30 15:43 ` Matthew Wilcox
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