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From:   Vivek Goyal <vgoyal@redhat.com>
To:     linux-fsdevel@vger.kernel.org, dan.j.williams@intel.com,
        jack@suse.cz, willy@infradead.org
Cc:     virtio-fs@redhat.com, slp@redhat.com, miklos@szeredi.hu,
        linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
        vgoyal@redhat.com
Subject: [PATCH v3 2/3] dax: Add a wakeup mode parameter to put_unlocked_entry()
Date:   Mon, 19 Apr 2021 17:36:35 -0400
Message-Id: <20210419213636.1514816-3-vgoyal@redhat.com>
In-Reply-To: <20210419213636.1514816-1-vgoyal@redhat.com>
References: <20210419213636.1514816-1-vgoyal@redhat.com>
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As of now put_unlocked_entry() always wakes up next waiter. In next
patches we want to wake up all waiters at one callsite. Hence, add a
parameter to the function.

This patch does not introduce any change of behavior.

Suggested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
 fs/dax.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 00978d0838b1..f19d76a6a493 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -275,11 +275,12 @@ static void wait_entry_unlocked(struct xa_state *xas, void *entry)
 	finish_wait(wq, &ewait.wait);
 }
 
-static void put_unlocked_entry(struct xa_state *xas, void *entry)
+static void put_unlocked_entry(struct xa_state *xas, void *entry,
+			       enum dax_entry_wake_mode mode)
 {
 	/* If we were the only waiter woken, wake the next one */
 	if (entry && !dax_is_conflict(entry))
-		dax_wake_entry(xas, entry, WAKE_NEXT);
+		dax_wake_entry(xas, entry, mode);
 }
 
 /*
@@ -633,7 +634,7 @@ struct page *dax_layout_busy_page_range(struct address_space *mapping,
 			entry = get_unlocked_entry(&xas, 0);
 		if (entry)
 			page = dax_busy_page(entry);
-		put_unlocked_entry(&xas, entry);
+		put_unlocked_entry(&xas, entry, WAKE_NEXT);
 		if (page)
 			break;
 		if (++scanned % XA_CHECK_SCHED)
@@ -675,7 +676,7 @@ static int __dax_invalidate_entry(struct address_space *mapping,
 	mapping->nrexceptional--;
 	ret = 1;
 out:
-	put_unlocked_entry(&xas, entry);
+	put_unlocked_entry(&xas, entry, WAKE_NEXT);
 	xas_unlock_irq(&xas);
 	return ret;
 }
@@ -954,7 +955,7 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev,
 	return ret;
 
  put_unlocked:
-	put_unlocked_entry(xas, entry);
+	put_unlocked_entry(xas, entry, WAKE_NEXT);
 	return ret;
 }
 
@@ -1695,7 +1696,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order)
 	/* Did we race with someone splitting entry or so? */
 	if (!entry || dax_is_conflict(entry) ||
 	    (order == 0 && !dax_is_pte_entry(entry))) {
-		put_unlocked_entry(&xas, entry);
+		put_unlocked_entry(&xas, entry, WAKE_NEXT);
 		xas_unlock_irq(&xas);
 		trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf,
 						      VM_FAULT_NOPAGE);
-- 
2.25.4