Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Fun set of conflict resolutions here...

For the mac80211 stuff, these were fortunately just parallel
adds.  Trivially resolved.

In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the
function phy_disable_interrupts() earlier in the file, whilst in
'net-next' the phy_error() call from this function was removed.

In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the
'rt_table_id' member of rtable collided with a bug fix in 'net' that
added a new struct member "rt_mtu_locked" which needs to be copied
over here.

The mlxsw driver conflict consisted of net-next separating
the span code and definitions into separate files, whilst
a 'net' bug fix made some changes to that moved code.

The mlx5 infiniband conflict resolution was quite non-trivial,
the RDMA tree's merge commit was used as a guide here, and
here are their notes:

====================

    Due to bug fixes found by the syzkaller bot and taken into the for-rc
    branch after development for the 4.17 merge window had already started
    being taken into the for-next branch, there were fairly non-trivial
    merge issues that would need to be resolved between the for-rc branch
    and the for-next branch.  This merge resolves those conflicts and
    provides a unified base upon which ongoing development for 4.17 can
    be based.

    Conflicts:
            drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524
            (IB/mlx5: Fix cleanup order on unload) added to for-rc and
            commit b5ca15ad7e61 (IB/mlx5: Add proper representors support)
            add as part of the devel cycle both needed to modify the
            init/de-init functions used by mlx5.  To support the new
            representors, the new functions added by the cleanup patch
            needed to be made non-static, and the init/de-init list
            added by the representors patch needed to be modified to
            match the init/de-init list changes made by the cleanup
            patch.
    Updates:
            drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function
            prototypes added by representors patch to reflect new function
            names as changed by cleanup patch
            drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init
            stage list to match new order from cleanup patch
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 12 deletions

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 66e1edbfb2b2..046469fcc1b8 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -955,15 +955,29 @@ static inline bool imap_needs_alloc(struct inode *inode,
 		(IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN);
 }
 
+static inline bool needs_cow_for_zeroing(struct xfs_bmbt_irec *imap, int nimaps)
+{
+	return nimaps &&
+		imap->br_startblock != HOLESTARTBLOCK &&
+		imap->br_state != XFS_EXT_UNWRITTEN;
+}
+
 static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags)
 {
 	/*
-	 * COW writes will allocate delalloc space, so we need to make sure
-	 * to take the lock exclusively here.
+	 * COW writes may allocate delalloc space or convert unwritten COW
+	 * extents, so we need to make sure to take the lock exclusively here.
 	 */
 	if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO)))
 		return true;
-	if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE))
+
+	/*
+	 * Extents not yet cached requires exclusive access, don't block.
+	 * This is an opencoded xfs_ilock_data_map_shared() to cater for the
+	 * non-blocking behaviour.
+	 */
+	if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
+	    !(ip->i_df.if_flags & XFS_IFEXTENTS))
 		return true;
 	return false;
 }
@@ -993,16 +1007,18 @@ xfs_file_iomap_begin(
 		return xfs_file_iomap_begin_delay(inode, offset, length, iomap);
 	}
 
-	if (need_excl_ilock(ip, flags)) {
+	if (need_excl_ilock(ip, flags))
 		lockmode = XFS_ILOCK_EXCL;
-		xfs_ilock(ip, XFS_ILOCK_EXCL);
-	} else {
-		lockmode = xfs_ilock_data_map_shared(ip);
-	}
+	else
+		lockmode = XFS_ILOCK_SHARED;
 
-	if ((flags & IOMAP_NOWAIT) && !(ip->i_df.if_flags & XFS_IFEXTENTS)) {
-		error = -EAGAIN;
-		goto out_unlock;
+	if (flags & IOMAP_NOWAIT) {
+		if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+			return -EAGAIN;
+		if (!xfs_ilock_nowait(ip, lockmode))
+			return -EAGAIN;
+	} else {
+		xfs_ilock(ip, lockmode);
 	}
 
 	ASSERT(offset <= mp->m_super->s_maxbytes);
@@ -1024,7 +1040,9 @@ xfs_file_iomap_begin(
 			goto out_unlock;
 	}
 
-	if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
+	if (xfs_is_reflink_inode(ip) &&
+	    ((flags & IOMAP_WRITE) ||
+	     ((flags & IOMAP_ZERO) && needs_cow_for_zeroing(&imap, nimaps)))) {
 		if (flags & IOMAP_DIRECT) {
 			/*
 			 * A reflinked inode will result in CoW alloc.