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From:   Shiyang Ruan <ruansy.fnst@fujitsu.com>
To:     <linux-kernel@vger.kernel.org>, <linux-xfs@vger.kernel.org>,
        <linux-nvdimm@lists.01.org>, <linux-mm@kvack.org>,
        <linux-fsdevel@vger.kernel.org>, <dm-devel@redhat.com>
CC:     <darrick.wong@oracle.com>, <dan.j.williams@intel.com>,
        <david@fromorbit.com>, <hch@lst.de>, <agk@redhat.com>,
        <snitzer@redhat.com>, <rgoldwyn@suse.de>
Subject: [PATCH v4 10/10] fs/dax: Remove useless functions
Date:   Fri, 4 Jun 2021 09:18:44 +0800
Message-ID: <20210604011844.1756145-11-ruansy.fnst@fujitsu.com>
In-Reply-To: <20210604011844.1756145-1-ruansy.fnst@fujitsu.com>
References: <20210604011844.1756145-1-ruansy.fnst@fujitsu.com>
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Precedence: bulk

Since owner tracking is triggerred by pmem device, these functions are
useless.  So remove them.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
 fs/dax.c | 46 ----------------------------------------------
 1 file changed, 46 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 1a7473f46df2..aff1e0f58967 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -334,48 +334,6 @@ static unsigned long dax_end_pfn(void *entry)
 	for (pfn = dax_to_pfn(entry); \
 			pfn < dax_end_pfn(entry); pfn++)
 
-/*
- * TODO: for reflink+dax we need a way to associate a single page with
- * multiple address_space instances at different linear_page_index()
- * offsets.
- */
-static void dax_associate_entry(void *entry, struct address_space *mapping,
-		struct vm_area_struct *vma, unsigned long address)
-{
-	unsigned long size = dax_entry_size(entry), pfn, index;
-	int i = 0;
-
-	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
-		return;
-
-	index = linear_page_index(vma, address & ~(size - 1));
-	for_each_mapped_pfn(entry, pfn) {
-		struct page *page = pfn_to_page(pfn);
-
-		WARN_ON_ONCE(page->mapping);
-		page->mapping = mapping;
-		page->index = index + i++;
-	}
-}
-
-static void dax_disassociate_entry(void *entry, struct address_space *mapping,
-		bool trunc)
-{
-	unsigned long pfn;
-
-	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED))
-		return;
-
-	for_each_mapped_pfn(entry, pfn) {
-		struct page *page = pfn_to_page(pfn);
-
-		WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
-		WARN_ON_ONCE(page->mapping && page->mapping != mapping);
-		page->mapping = NULL;
-		page->index = 0;
-	}
-}
-
 static struct page *dax_busy_page(void *entry)
 {
 	unsigned long pfn;
@@ -554,7 +512,6 @@ static void *grab_mapping_entry(struct xa_state *xas,
 			xas_lock_irq(xas);
 		}
 
-		dax_disassociate_entry(entry, mapping, false);
 		xas_store(xas, NULL);	/* undo the PMD join */
 		dax_wake_entry(xas, entry, WAKE_ALL);
 		mapping->nrpages -= PG_PMD_NR;
@@ -691,7 +648,6 @@ static int __dax_invalidate_entry(struct address_space *mapping,
 	    (xas_get_mark(&xas, PAGECACHE_TAG_DIRTY) ||
 	     xas_get_mark(&xas, PAGECACHE_TAG_TOWRITE)))
 		goto out;
-	dax_disassociate_entry(entry, mapping, trunc);
 	xas_store(&xas, NULL);
 	mapping->nrpages -= 1UL << dax_entry_order(entry);
 	ret = 1;
@@ -785,8 +741,6 @@ static void *dax_insert_entry(struct xa_state *xas,
 	if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {
 		void *old;
 
-		dax_disassociate_entry(entry, mapping, false);
-		dax_associate_entry(new_entry, mapping, vmf->vma, vmf->address);
 		/*
 		 * Only swap our new entry into the page cache if the current
 		 * entry is a zero page or an empty entry.  If a normal PTE or
-- 
2.31.1