From: Matthew Wilcox <willy@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org,
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>,
linux-nilfs@vger.kernel.org
Subject: [PATCH v9 56/61] nilfs2: Convert to XArray
Date: Tue, 13 Mar 2018 06:26:34 -0700 [thread overview]
Message-ID: <20180313132639.17387-57-willy@infradead.org> (raw)
In-Reply-To: <20180313132639.17387-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
I'm not 100% convinced that the rewrite of nilfs_copy_back_pages is
correct, but it will at least have different bugs from the current
version.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
fs/nilfs2/btnode.c | 37 +++++++++++-----------------
fs/nilfs2/page.c | 72 +++++++++++++++++++++++++++++++-----------------------
2 files changed, 56 insertions(+), 53 deletions(-)
diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index dec98cab729d..68797603bc08 100644
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -177,42 +177,36 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc,
ctxt->newbh = NULL;
if (inode->i_blkbits == PAGE_SHIFT) {
- lock_page(obh->b_page);
- /*
- * We cannot call radix_tree_preload for the kernels older
- * than 2.6.23, because it is not exported for modules.
- */
+ void *entry;
+ struct page *opage = obh->b_page;
+ lock_page(opage);
retry:
- err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
- if (err)
- goto failed_unlock;
/* BUG_ON(oldkey != obh->b_page->index); */
- if (unlikely(oldkey != obh->b_page->index))
- NILFS_PAGE_BUG(obh->b_page,
+ if (unlikely(oldkey != opage->index))
+ NILFS_PAGE_BUG(opage,
"invalid oldkey %lld (newkey=%lld)",
(unsigned long long)oldkey,
(unsigned long long)newkey);
- xa_lock_irq(&btnc->i_pages);
- err = radix_tree_insert(&btnc->i_pages, newkey, obh->b_page);
- xa_unlock_irq(&btnc->i_pages);
+ entry = xa_cmpxchg(&btnc->i_pages, newkey, NULL, opage, GFP_NOFS);
/*
* Note: page->index will not change to newkey until
* nilfs_btnode_commit_change_key() will be called.
* To protect the page in intermediate state, the page lock
* is held.
*/
- radix_tree_preload_end();
- if (!err)
+ if (!entry)
return 0;
- else if (err != -EEXIST)
+ if (xa_is_err(entry)) {
+ err = xa_err(entry);
goto failed_unlock;
+ }
err = invalidate_inode_pages2_range(btnc, newkey, newkey);
if (!err)
goto retry;
/* fallback to copy mode */
- unlock_page(obh->b_page);
+ unlock_page(opage);
}
nbh = nilfs_btnode_create_block(btnc, newkey);
@@ -252,9 +246,8 @@ void nilfs_btnode_commit_change_key(struct address_space *btnc,
mark_buffer_dirty(obh);
xa_lock_irq(&btnc->i_pages);
- radix_tree_delete(&btnc->i_pages, oldkey);
- radix_tree_tag_set(&btnc->i_pages, newkey,
- PAGECACHE_TAG_DIRTY);
+ __xa_erase(&btnc->i_pages, oldkey);
+ __xa_set_tag(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY);
xa_unlock_irq(&btnc->i_pages);
opage->index = obh->b_blocknr = newkey;
@@ -283,9 +276,7 @@ void nilfs_btnode_abort_change_key(struct address_space *btnc,
return;
if (nbh == NULL) { /* blocksize == pagesize */
- xa_lock_irq(&btnc->i_pages);
- radix_tree_delete(&btnc->i_pages, newkey);
- xa_unlock_irq(&btnc->i_pages);
+ xa_erase(&btnc->i_pages, newkey);
unlock_page(ctxt->bh->b_page);
} else
brelse(nbh);
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index 4cb850a6f1c2..a3995406d5d3 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -304,10 +304,10 @@ int nilfs_copy_dirty_pages(struct address_space *dmap,
void nilfs_copy_back_pages(struct address_space *dmap,
struct address_space *smap)
{
+ XA_STATE(xas, &dmap->i_pages, 0);
struct pagevec pvec;
unsigned int i, n;
pgoff_t index = 0;
- int err;
pagevec_init(&pvec);
repeat:
@@ -317,43 +317,56 @@ void nilfs_copy_back_pages(struct address_space *dmap,
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i], *dpage;
- pgoff_t offset = page->index;
+ xas_set(&xas, page->index);
lock_page(page);
- dpage = find_lock_page(dmap, offset);
+ do {
+ xas_lock_irq(&xas);
+ dpage = xas_create(&xas);
+ if (!xas_error(&xas))
+ break;
+ xas_unlock_irq(&xas);
+ if (!xas_nomem(&xas, GFP_NOFS)) {
+ unlock_page(page);
+ /*
+ * Callers have a touching faith that this
+ * function cannot fail. Just leak the page.
+ * Other pages may be salvagable if the
+ * xarray doesn't need to allocate memory
+ * to store them.
+ */
+ WARN_ON(1);
+ page->mapping = NULL;
+ put_page(page);
+ goto shadow_remove;
+ }
+ } while (1);
+
if (dpage) {
- /* override existing page on the destination cache */
+ get_page(dpage);
+ xas_unlock_irq(&xas);
+ lock_page(dpage);
+ /* override existing page in the destination cache */
WARN_ON(PageDirty(dpage));
nilfs_copy_page(dpage, page, 0);
unlock_page(dpage);
put_page(dpage);
} else {
- struct page *page2;
-
- /* move the page to the destination cache */
- xa_lock_irq(&smap->i_pages);
- page2 = radix_tree_delete(&smap->i_pages, offset);
- WARN_ON(page2 != page);
-
- smap->nrpages--;
- xa_unlock_irq(&smap->i_pages);
-
- xa_lock_irq(&dmap->i_pages);
- err = radix_tree_insert(&dmap->i_pages, offset, page);
- if (unlikely(err < 0)) {
- WARN_ON(err == -EEXIST);
- page->mapping = NULL;
- put_page(page); /* for cache */
- } else {
- page->mapping = dmap;
- dmap->nrpages++;
- if (PageDirty(page))
- radix_tree_tag_set(&dmap->i_pages,
- offset,
- PAGECACHE_TAG_DIRTY);
- }
+ xas_store(&xas, page);
+ page->mapping = dmap;
+ dmap->nrpages++;
+ if (PageDirty(page))
+ xas_set_tag(&xas, PAGECACHE_TAG_DIRTY);
xa_unlock_irq(&dmap->i_pages);
}
+
+shadow_remove:
+ /* remove the page from the shadow cache */
+ xa_lock_irq(&smap->i_pages);
+ WARN_ON(__xa_erase(&smap->i_pages, xas.xa_index) != page);
+ smap->nrpages--;
+ xa_unlock_irq(&smap->i_pages);
+
unlock_page(page);
}
pagevec_release(&pvec);
@@ -476,8 +489,7 @@ int __nilfs_clear_page_dirty(struct page *page)
if (mapping) {
xa_lock_irq(&mapping->i_pages);
if (test_bit(PG_dirty, &page->flags)) {
- radix_tree_tag_clear(&mapping->i_pages,
- page_index(page),
+ __xa_clear_tag(&mapping->i_pages, page_index(page),
PAGECACHE_TAG_DIRTY);
xa_unlock_irq(&mapping->i_pages);
return clear_page_dirty_for_io(page);
--
2.16.1
next prev parent reply other threads:[~2018-03-13 13:29 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 13:25 [PATCH v9 00/61] XArray v9 Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 01/61] mac80211_hwsim: Use DEFINE_IDA Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 02/61] radix tree: Use GFP_ZONEMASK bits of gfp_t for flags Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 03/61] arm64: Turn flush_dcache_mmap_lock into a no-op Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 04/61] unicore32: " Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 05/61] Export __set_page_dirty Matthew Wilcox
2018-03-27 0:28 ` Darrick J. Wong
2018-03-13 13:25 ` [PATCH v9 06/61] fscache: Use appropriate radix tree accessors Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 07/61] xarray: Add the xa_lock to the radix_tree_root Matthew Wilcox
2018-04-12 20:59 ` Ross Zwisler
2018-04-12 21:10 ` Matthew Wilcox
2018-04-12 21:16 ` Ross Zwisler
2018-04-12 21:22 ` Matthew Wilcox
2018-04-12 21:27 ` Ross Zwisler
2018-03-13 13:25 ` [PATCH v9 08/61] page cache: Use xa_lock Matthew Wilcox
2018-03-16 18:06 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 09/61] xarray: Replace exceptional entries Matthew Wilcox
2018-03-16 18:53 ` Josef Bacik
2018-03-16 19:06 ` Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 10/61] xarray: Change definition of sibling entries Matthew Wilcox
2018-03-16 19:00 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 11/61] xarray: Add definition of struct xarray Matthew Wilcox
2018-03-16 19:05 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 12/61] xarray: Define struct xa_node Matthew Wilcox
2018-03-16 19:11 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 13/61] xarray: Add documentation Matthew Wilcox
2018-03-16 19:12 ` Josef Bacik
2018-03-13 13:25 ` [PATCH v9 14/61] xarray: Add xa_load Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 15/61] xarray: Add xa_get_tag, xa_set_tag and xa_clear_tag Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 16/61] xarray: Add xa_store Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 17/61] xarray: Add xa_cmpxchg and xa_insert Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 18/61] xarray: Add xa_for_each Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 19/61] xarray: Add xa_extract Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 20/61] xarray: Add xa_destroy Matthew Wilcox
2018-03-13 13:25 ` [PATCH v9 21/61] xarray: Add xas_next and xas_prev Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 22/61] xarray: Add xas_create_range Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 23/61] xarray: Add MAINTAINERS entry Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 24/61] page cache: Rearrange address_space Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 25/61] page cache: Convert hole search to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 26/61] page cache: Add and replace pages using the XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 27/61] page cache: Convert page deletion to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 28/61] page cache: Convert page cache lookups " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 29/61] page cache: Convert delete_batch " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 30/61] page cache: Remove stray radix comment Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 31/61] page cache: Convert filemap_range_has_page to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 32/61] mm: Convert page-writeback " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 33/61] mm: Convert workingset " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 34/61] mm: Convert truncate " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 35/61] mm: Convert add_to_swap_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 36/61] mm: Convert delete_from_swap_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 37/61] mm: Convert __do_page_cache_readahead " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 38/61] mm: Convert page migration " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 39/61] mm: Convert huge_memory " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 40/61] mm: Convert collapse_shmem " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 41/61] mm: Convert khugepaged_scan_shmem " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 42/61] pagevec: Use xa_tag_t Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 43/61] shmem: Convert replace to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 44/61] shmem: Convert shmem_confirm_swap " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 45/61] shmem: Convert find_swap_entry " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 46/61] shmem: Convert shmem_add_to_page_cache " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 47/61] shmem: Convert shmem_alloc_hugepage " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 48/61] shmem: Convert shmem_free_swap " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 49/61] shmem: Convert shmem_partial_swap_usage " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 50/61] memfd: Convert shmem_tag_pins " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 51/61] memfd: Convert shmem_wait_for_pins " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 52/61] shmem: Comment fixups Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 53/61] btrfs: Convert page cache to XArray Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 54/61] fs: Convert buffer " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 55/61] fs: Convert writeback " Matthew Wilcox
2018-03-13 13:26 ` Matthew Wilcox [this message]
2018-03-13 13:26 ` [PATCH v9 57/61] f2fs: Convert " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 58/61] lustre: " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 59/61] dax: " Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 60/61] page cache: Finish XArray conversion Matthew Wilcox
2018-03-13 13:26 ` [PATCH v9 61/61] radix tree: Remove unused functions Matthew Wilcox
2018-03-26 22:36 ` [PATCH v9 00/61] XArray v9 Andrew Morton
2018-03-26 23:26 ` Matthew Wilcox
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