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From:   Matthew Wilcox <willy@infradead.org>
To:     linux-kernel@vger.kernel.org
Cc:     Matthew Wilcox <mawilcox@microsoft.com>, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org,
        linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Stefano Stabellini <sstabellini@kernel.org>,
        iommu@lists.linux-foundation.org, linux-remoteproc@vger.kernel.org,
        linux-s390@vger.kernel.org, intel-gfx@lists.freedesktop.org,
        cgroups@vger.kernel.org, linux-sh@vger.kernel.org,
        David Howells <dhowells@redhat.com>
Subject: [PATCH v6 61/99] dax: Convert dax_writeback_one to XArray
Date:   Wed, 17 Jan 2018 12:21:25 -0800
Message-Id: <20180117202203.19756-62-willy@infradead.org>
In-Reply-To: <20180117202203.19756-1-willy@infradead.org>
References: <20180117202203.19756-1-willy@infradead.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Matthew Wilcox <mawilcox@microsoft.com>

Likewise easy

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
 fs/dax.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 9a30224da4d6..b66b8c896ed8 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -632,8 +632,7 @@ static int dax_writeback_one(struct block_device *bdev,
 		struct dax_device *dax_dev, struct address_space *mapping,
 		pgoff_t index, void *entry)
 {
-	struct radix_tree_root *pages = &mapping->pages;
-	XA_STATE(xas, pages, index);
+	XA_STATE(xas, &mapping->pages, index);
 	void *entry2, *kaddr;
 	long ret = 0, id;
 	sector_t sector;
@@ -648,7 +647,7 @@ static int dax_writeback_one(struct block_device *bdev,
 	if (WARN_ON(!xa_is_value(entry)))
 		return -EIO;
 
-	xa_lock_irq(&mapping->pages);
+	xas_lock_irq(&xas);
 	entry2 = get_unlocked_mapping_entry(&xas);
 	/* Entry got punched out / reallocated? */
 	if (!entry2 || WARN_ON_ONCE(!xa_is_value(entry2)))
@@ -667,7 +666,7 @@ static int dax_writeback_one(struct block_device *bdev,
 	}
 
 	/* Another fsync thread may have already written back this entry */
-	if (!radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE))
+	if (!xas_get_tag(&xas, PAGECACHE_TAG_TOWRITE))
 		goto put_unlocked;
 	/* Lock the entry to serialize with page faults */
 	entry = lock_slot(&xas);
@@ -678,8 +677,8 @@ static int dax_writeback_one(struct block_device *bdev,
 	 * at the entry only under xa_lock and once they do that they will
 	 * see the entry locked and wait for it to unlock.
 	 */
-	radix_tree_tag_clear(pages, index, PAGECACHE_TAG_TOWRITE);
-	xa_unlock_irq(&mapping->pages);
+	xas_clear_tag(&xas, PAGECACHE_TAG_TOWRITE);
+	xas_unlock_irq(&xas);
 
 	/*
 	 * Even if dax_writeback_mapping_range() was given a wbc->range_start
@@ -717,9 +716,7 @@ static int dax_writeback_one(struct block_device *bdev,
 	 * the pfn mappings are writeprotected and fault waits for mapping
 	 * entry lock.
 	 */
-	xa_lock_irq(&mapping->pages);
-	radix_tree_tag_clear(pages, index, PAGECACHE_TAG_DIRTY);
-	xa_unlock_irq(&mapping->pages);
+	xa_clear_tag(&mapping->pages, index, PAGECACHE_TAG_DIRTY);
 	trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT);
  dax_unlock:
 	dax_read_unlock(id);
@@ -728,7 +725,7 @@ static int dax_writeback_one(struct block_device *bdev,
 
  put_unlocked:
 	put_unlocked_mapping_entry(&xas, entry2);
-	xa_unlock_irq(&mapping->pages);
+	xas_unlock_irq(&xas);
 	return ret;
 }
 
-- 
2.15.1