Revision 9f141d6ef6258a3a37a045842d9ba7e68f368956 authored by Jan Kara on 19 October 2016, 12:34:31 UTC, committed by Dan Williams on 27 December 2016, 04:29:25 UTC
Currently ->iomap_begin() handler is called with entry lock held. If the
filesystem held any locks between ->iomap_begin() and ->iomap_end()
(such as ext4 which will want to hold transaction open), this would cause
lock inversion with the iomap_apply() from standard IO path which first
calls ->iomap_begin() and only then calls ->actor() callback which grabs
entry locks for DAX (if it faults when copying from/to user provided
buffers).

Fix the problem by nesting grabbing of entry lock inside ->iomap_begin()
- ->iomap_end() pair.

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
1 parent f449b93
Raw File
makelst
#!/bin/sh
# A script to dump mixed source code & assembly
# with correct relocations from System.map
# Requires the following lines in makefile:
#%.lst: %.c
#	$(CC) $(c_flags) -g -c -o $*.o $< &&
#	$(srctree)/scripts/makelst $*.o System.map $(OBJDUMP) > $@
#
# Copyright (C) 2000 IBM Corporation
# Author(s): DJ Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
#            William Stearns <wstearns@pobox.com>
#

# awk style field access
field() {
  shift $1 ; echo $1
}

t1=`$3 --syms $1 | grep .text | grep -m1 " F "`
if [ -n "$t1" ]; then
  t2=`field 6 $t1`
  if [ ! -r $2 ]; then
    echo "No System.map" >&2
  else
    t3=`grep $t2 $2`
    t4=`field 1 $t3`
    t5=`field 1 $t1`
    t6=`printf "%lu" $((0x$t4 - 0x$t5))`
  fi
fi
$3 -r --source --adjust-vma=${t6:-0} $1
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