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From: Jan Kara <jack@suse.cz>
To: <linux-fsdevel@vger.kernel.org>
Cc: <linux-ext4@vger.kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	"Darrick J. Wong" <djwong@kernel.org>, Ted Tso <tytso@mit.edu>,
	Dave Chinner <david@fromorbit.com>,
	Matthew Wilcox <willy@infradead.org>, <linux-mm@kvack.org>,
	<linux-xfs@vger.kernel.org>,
	linux-f2fs-devel@lists.sourceforge.net,
	linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org,
	Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH 09/14] xfs: Convert double locking of MMAPLOCK to use VFS helpers
Date: Mon, 12 Jul 2021 18:56:00 +0200	[thread overview]
Message-ID: <20210712165609.13215-9-jack@suse.cz> (raw)
In-Reply-To: <20210712163901.29514-1-jack@suse.cz>

Convert places in XFS that take MMAPLOCK for two inodes to use helper
VFS provides for it (filemap_invalidate_down_write_two()). Note that
this changes lock ordering for MMAPLOCK from inode number based ordering
to pointer based ordering VFS generally uses.

CC: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/xfs/xfs_bmap_util.c | 15 ++++++++-------
 fs/xfs/xfs_inode.c     | 37 +++++++++++--------------------------
 2 files changed, 19 insertions(+), 33 deletions(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 213a97a921bb..1cd3f940fa6a 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1626,7 +1626,6 @@ xfs_swap_extents(
 	struct xfs_bstat	*sbp = &sxp->sx_stat;
 	int			src_log_flags, target_log_flags;
 	int			error = 0;
-	int			lock_flags;
 	uint64_t		f;
 	int			resblks = 0;
 	unsigned int		flags = 0;
@@ -1638,8 +1637,8 @@ xfs_swap_extents(
 	 * do the rest of the checks.
 	 */
 	lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
-	lock_flags = XFS_MMAPLOCK_EXCL;
-	xfs_lock_two_inodes(ip, XFS_MMAPLOCK_EXCL, tip, XFS_MMAPLOCK_EXCL);
+	filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
+				    VFS_I(tip)->i_mapping);
 
 	/* Verify that both files have the same format */
 	if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
@@ -1711,7 +1710,6 @@ xfs_swap_extents(
 	 * or cancel will unlock the inodes from this point onwards.
 	 */
 	xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
-	lock_flags |= XFS_ILOCK_EXCL;
 	xfs_trans_ijoin(tp, ip, 0);
 	xfs_trans_ijoin(tp, tip, 0);
 
@@ -1830,13 +1828,16 @@ xfs_swap_extents(
 	trace_xfs_swap_extent_after(ip, 0);
 	trace_xfs_swap_extent_after(tip, 1);
 
+out_unlock_ilock:
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	xfs_iunlock(tip, XFS_ILOCK_EXCL);
 out_unlock:
-	xfs_iunlock(ip, lock_flags);
-	xfs_iunlock(tip, lock_flags);
+	filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
+				      VFS_I(tip)->i_mapping);
 	unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
 	return error;
 
 out_trans_cancel:
 	xfs_trans_cancel(tp);
-	goto out_unlock;
+	goto out_unlock_ilock;
 }
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index d6a8ac76b45d..3c0bb21453dc 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -552,12 +552,10 @@ xfs_lock_inodes(
 }
 
 /*
- * xfs_lock_two_inodes() can only be used to lock one type of lock at a time -
- * the mmaplock or the ilock, but not more than one type at a time. If we lock
- * more than one at a time, lockdep will report false positives saying we have
- * violated locking orders.  The iolock must be double-locked separately since
- * we use i_rwsem for that.  We now support taking one lock EXCL and the other
- * SHARED.
+ * xfs_lock_two_inodes() can only be used to lock ilock. The iolock and
+ * mmaplock must be double-locked separately since we use i_rwsem and
+ * invalidate_lock for that. We now support taking one lock EXCL and the
+ * other SHARED.
  */
 void
 xfs_lock_two_inodes(
@@ -575,15 +573,8 @@ xfs_lock_two_inodes(
 	ASSERT(hweight32(ip1_mode) == 1);
 	ASSERT(!(ip0_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
 	ASSERT(!(ip1_mode & (XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)));
-	ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
-	       !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
-	ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
-	       !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
-	ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
-	       !(ip0_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
-	ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) ||
-	       !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL)));
-
+	ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)));
+	ASSERT(!(ip1_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)));
 	ASSERT(ip0->i_ino != ip1->i_ino);
 
 	if (ip0->i_ino > ip1->i_ino) {
@@ -3748,11 +3739,8 @@ xfs_ilock2_io_mmap(
 	ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
 	if (ret)
 		return ret;
-	if (ip1 == ip2)
-		xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
-	else
-		xfs_lock_two_inodes(ip1, XFS_MMAPLOCK_EXCL,
-				    ip2, XFS_MMAPLOCK_EXCL);
+	filemap_invalidate_lock_two(VFS_I(ip1)->i_mapping,
+				    VFS_I(ip2)->i_mapping);
 	return 0;
 }
 
@@ -3762,12 +3750,9 @@ xfs_iunlock2_io_mmap(
 	struct xfs_inode	*ip1,
 	struct xfs_inode	*ip2)
 {
-	bool			same_inode = (ip1 == ip2);
-
-	xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL);
-	if (!same_inode)
-		xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+	filemap_invalidate_unlock_two(VFS_I(ip1)->i_mapping,
+				      VFS_I(ip2)->i_mapping);
 	inode_unlock(VFS_I(ip2));
-	if (!same_inode)
+	if (ip1 != ip2)
 		inode_unlock(VFS_I(ip1));
 }
-- 
2.26.2


  parent reply	other threads:[~2021-07-12 16:56 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-12 16:55 [PATCH 0/14 v9] fs: Hole punch vs page cache filling races Jan Kara
2021-07-12 16:55 ` [PATCH 01/14] mm: Fix comments mentioning i_mutex Jan Kara
2021-07-12 16:55 ` [PATCH 02/14] documentation: Sync file_operations members with reality Jan Kara
2021-07-13  1:02   ` Darrick J. Wong
2021-07-12 16:55 ` [PATCH 03/14] mm: Protect operations adding pages to page cache with invalidate_lock Jan Kara
2021-07-13  1:25   ` Darrick J. Wong
2021-07-13 11:11     ` Jan Kara
2021-07-13  6:25   ` Christoph Hellwig
2021-07-13 12:35     ` Jan Kara
2021-07-12 16:55 ` [PATCH 04/14] mm: Add functions to lock invalidate_lock for two mappings Jan Kara
2021-07-12 16:55 ` [PATCH 05/14] ext4: Convert to use mapping->invalidate_lock Jan Kara
2021-07-12 16:55 ` [PATCH 06/14] ext2: Convert to using invalidate_lock Jan Kara
2021-07-12 16:55 ` [PATCH 07/14] xfs: Refactor xfs_isilocked() Jan Kara
2021-07-12 16:55 ` [PATCH 08/14] xfs: Convert to use invalidate_lock Jan Kara
2021-07-12 16:56 ` Jan Kara [this message]
2021-07-12 16:56 ` [PATCH 10/14] zonefs: Convert to using invalidate_lock Jan Kara
2021-07-12 16:56 ` [PATCH 11/14] f2fs: " Jan Kara
2021-07-12 16:56 ` [PATCH 12/14] fuse: " Jan Kara
2021-07-12 16:56 ` [PATCH 13/14] ceph: Fix race between hole punch and page fault Jan Kara
2021-07-12 16:56 ` [PATCH 14/14] cifs: " Jan Kara
  -- strict thread matches above, loose matches on Subject: below --
2021-07-15 13:40 [PATCH 0/14 v10] fs: Hole punch vs page cache filling races Jan Kara
2021-07-15 13:40 ` [PATCH 09/14] xfs: Convert double locking of MMAPLOCK to use VFS helpers Jan Kara
2021-06-15  9:17 [PATCH 0/14 v8] fs: Hole punch vs page cache filling races Jan Kara
2021-06-15  9:17 ` [PATCH 09/14] xfs: Convert double locking of MMAPLOCK to use VFS helpers Jan Kara
2021-06-16  5:38   ` Christoph Hellwig
2021-06-07 14:52 [PATCH 0/14 v7] fs: Hole punch vs page cache filling races Jan Kara
2021-06-07 14:52 ` [PATCH 09/14] xfs: Convert double locking of MMAPLOCK to use VFS helpers Jan Kara
2021-06-07 15:57   ` Darrick J. Wong

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