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.