NVDIMM Device and Persistent Memory development
 help / color / Atom feed
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org
Subject: [PATCH v2 1/4] mm: Introduce and use mapping_empty
Date: Mon, 26 Oct 2020 15:18:46 +0000
Message-ID: <20201026151849.24232-2-willy@infradead.org> (raw)
In-Reply-To: <20201026151849.24232-1-willy@infradead.org>

Instead of checking the two counters (nrpages and nrexceptional), we
can just check whether i_pages is empty.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
---
 fs/block_dev.c          |  2 +-
 fs/dax.c                |  2 +-
 fs/gfs2/glock.c         |  3 +--
 include/linux/pagemap.h |  5 +++++
 mm/truncate.c           | 18 +++---------------
 5 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9e84b1928b94..34105f66e12f 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -79,7 +79,7 @@ static void kill_bdev(struct block_device *bdev)
 {
 	struct address_space *mapping = bdev->bd_inode->i_mapping;
 
-	if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+	if (mapping_empty(mapping))
 		return;
 
 	invalidate_bh_lrus();
diff --git a/fs/dax.c b/fs/dax.c
index 5b47834f2e1b..53ed0ab8c958 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -965,7 +965,7 @@ int dax_writeback_mapping_range(struct address_space *mapping,
 	if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
 		return -EIO;
 
-	if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
+	if (mapping_empty(mapping) || wbc->sync_mode != WB_SYNC_ALL)
 		return 0;
 
 	trace_dax_writeback_range(inode, xas.xa_index, end_index);
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 5441c17562c5..bfad01ce096d 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -273,8 +273,7 @@ static void __gfs2_glock_put(struct gfs2_glock *gl)
 	if (mapping) {
 		truncate_inode_pages_final(mapping);
 		if (!gfs2_withdrawn(sdp))
-			GLOCK_BUG_ON(gl, mapping->nrpages ||
-				     mapping->nrexceptional);
+			GLOCK_BUG_ON(gl, !mapping_empty(mapping));
 	}
 	trace_gfs2_glock_put(gl);
 	sdp->sd_lockstruct.ls_ops->lm_put_lock(gl);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index dc3390e6ee3e..86143d36d028 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -18,6 +18,11 @@
 
 struct pagevec;
 
+static inline bool mapping_empty(struct address_space *mapping)
+{
+	return xa_empty(&mapping->i_pages);
+}
+
 /*
  * Bits in mapping->flags.
  */
diff --git a/mm/truncate.c b/mm/truncate.c
index 11ef90d7e3af..58524aaf67e2 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -342,7 +342,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
 	struct page *	page;
 	bool partial_end;
 
-	if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+	if (mapping_empty(mapping))
 		goto out;
 
 	/*
@@ -470,9 +470,6 @@ EXPORT_SYMBOL(truncate_inode_pages);
  */
 void truncate_inode_pages_final(struct address_space *mapping)
 {
-	unsigned long nrexceptional;
-	unsigned long nrpages;
-
 	/*
 	 * Page reclaim can not participate in regular inode lifetime
 	 * management (can't call iput()) and thus can race with the
@@ -482,16 +479,7 @@ void truncate_inode_pages_final(struct address_space *mapping)
 	 */
 	mapping_set_exiting(mapping);
 
-	/*
-	 * When reclaim installs eviction entries, it increases
-	 * nrexceptional first, then decreases nrpages.  Make sure we see
-	 * this in the right order or we might miss an entry.
-	 */
-	nrpages = mapping->nrpages;
-	smp_rmb();
-	nrexceptional = mapping->nrexceptional;
-
-	if (nrpages || nrexceptional) {
+	if (!mapping_empty(mapping)) {
 		/*
 		 * As truncation uses a lockless tree lookup, cycle
 		 * the tree lock to make sure any ongoing tree
@@ -657,7 +645,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
 	int ret2 = 0;
 	int did_range_unmap = 0;
 
-	if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+	if (mapping_empty(mapping))
 		goto out;
 
 	pagevec_init(&pvec);
-- 
2.28.0
_______________________________________________
Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org
To unsubscribe send an email to linux-nvdimm-leave@lists.01.org

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26 15:18 [PATCH v2 0/4] Remove nrexceptional tracking Matthew Wilcox (Oracle)
2020-10-26 15:18 ` Matthew Wilcox (Oracle) [this message]
2021-01-21 20:42   ` [PATCH v2 1/4] mm: Introduce and use mapping_empty Johannes Weiner
2021-01-21 21:18     ` Matthew Wilcox
2020-10-26 15:18 ` [PATCH v2 2/4] mm: Stop accounting shadow entries Matthew Wilcox (Oracle)
2021-01-21 20:44   ` Johannes Weiner
2020-10-26 15:18 ` [PATCH v2 3/4] dax: Account DAX entries as nrpages Matthew Wilcox (Oracle)
2021-01-21 20:46   ` Johannes Weiner
2020-10-26 15:18 ` [PATCH v2 4/4] mm: Remove nrexceptional from inode Matthew Wilcox (Oracle)
2021-01-21 20:47   ` Johannes Weiner
2021-01-21 18:43 ` [PATCH v2 0/4] Remove nrexceptional tracking Matthew Wilcox
2021-03-13  2:35   ` Matthew Wilcox
2021-01-22 19:38 ` William Kucharski

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201026151849.24232-2-willy@infradead.org \
    --to=willy@infradead.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-nvdimm@lists.01.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

NVDIMM Device and Persistent Memory development

Archives are clonable:
	git clone --mirror https://lore.kernel.org/nvdimm/0 nvdimm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 nvdimm nvdimm/ https://lore.kernel.org/nvdimm \
		nvdimm@lists.linux.dev
	public-inbox-index nvdimm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/dev.linux.lists.nvdimm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git