Merge tag 'v5.0-rc6' into for-5.1/block

Pull in 5.0-rc6 to avoid a dumb merge conflict with fs/iomap.c.
This is needed since io_uring is now based on the block branch,
to avoid a conflict between the multi-page bvecs and the bits
of io_uring that touch the core block parts.

* tag 'v5.0-rc6': (525 commits)
  Linux 5.0-rc6
  x86/mm: Make set_pmd_at() paravirt aware
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  MAINTAINERS: unify reference to xen-devel list
  x86/mm/cpa: Fix set_mce_nospec()
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment
  net: dsa: b53: Fix for failure when irq is not defined in dt
  blktrace: Show requests without sector
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
  geneve: should not call rt6_lookup() when ipv6 was disabled
  KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
  KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
  kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
  signal: Better detection of synchronous signals
  ...

1 files changed, 17 insertions, 2 deletions

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index eedc5e0156ff..4f5f2ff3f70f 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -776,10 +776,26 @@ _xfs_buf_read(
 }
 
 /*
+ * Set buffer ops on an unchecked buffer and validate it, if possible.
+ *
  * If the caller passed in an ops structure and the buffer doesn't have ops
  * assigned, set the ops and use them to verify the contents.  If the contents
  * cannot be verified, we'll clear XBF_DONE.  We assume the buffer has no
  * recorded errors and is already in XBF_DONE state.
+ *
+ * Under normal operations, every in-core buffer must have buffer ops assigned
+ * to them when the buffer is read in from disk so that we can validate the
+ * metadata.
+ *
+ * However, there are two scenarios where one can encounter in-core buffers
+ * that don't have buffer ops.  The first is during log recovery of buffers on
+ * a V4 filesystem, though these buffers are purged at the end of recovery.
+ *
+ * The other is online repair, which tries to match arbitrary metadata blocks
+ * with btree types in order to find the root.  If online repair doesn't match
+ * the buffer with /any/ btree type, the buffer remains in memory in DONE state
+ * with no ops, and a subsequent read_buf call from elsewhere will not set the
+ * ops.  This function helps us fix this situation.
  */
 int
 xfs_buf_ensure_ops(
@@ -1536,8 +1552,7 @@ __xfs_buf_submit(
 		xfs_buf_ioerror(bp, -EIO);
 		bp->b_flags &= ~XBF_DONE;
 		xfs_buf_stale(bp);
-		if (bp->b_flags & XBF_ASYNC)
-			xfs_buf_ioend(bp);
+		xfs_buf_ioend(bp);
 		return -EIO;
 	}