Revision 03cdadb04077b9311bbc67d98cc5401aff76482d authored by Dan Williams on 26 February 2016, 23:19:43 UTC, committed by Linus Torvalds on 27 February 2016, 18:28:52 UTC
The recent *sync enabling discovered that we are inserting into the
block_device pagecache counter to the expectations of the dirty data
tracking for dax mappings.  This can lead to data corruption.

We want to support DAX for block devices eventually, but it requires
wider changes to properly manage the pagecache.

   dump_stack+0x85/0xc2
   dax_writeback_mapping_range+0x60/0xe0
   blkdev_writepages+0x3f/0x50
   do_writepages+0x21/0x30
   __filemap_fdatawrite_range+0xc6/0x100
   filemap_write_and_wait+0x4a/0xa0
   set_blocksize+0x70/0xd0
   sb_set_blocksize+0x1d/0x50
   ext4_fill_super+0x75b/0x3360
   mount_bdev+0x180/0x1b0
   ext4_mount+0x15/0x20
   mount_fs+0x38/0x170

Mark the support broken so its disabled by default, but otherwise still
available for testing.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent a4a8481
Raw File
ubsan.h
#ifndef _LIB_UBSAN_H
#define _LIB_UBSAN_H

enum {
	type_kind_int = 0,
	type_kind_float = 1,
	type_unknown = 0xffff
};

struct type_descriptor {
	u16 type_kind;
	u16 type_info;
	char type_name[1];
};

struct source_location {
	const char *file_name;
	union {
		unsigned long reported;
		struct {
			u32 line;
			u32 column;
		};
	};
};

struct overflow_data {
	struct source_location location;
	struct type_descriptor *type;
};

struct type_mismatch_data {
	struct source_location location;
	struct type_descriptor *type;
	unsigned long alignment;
	unsigned char type_check_kind;
};

struct nonnull_arg_data {
	struct source_location location;
	struct source_location attr_location;
	int arg_index;
};

struct nonnull_return_data {
	struct source_location location;
	struct source_location attr_location;
};

struct vla_bound_data {
	struct source_location location;
	struct type_descriptor *type;
};

struct out_of_bounds_data {
	struct source_location location;
	struct type_descriptor *array_type;
	struct type_descriptor *index_type;
};

struct shift_out_of_bounds_data {
	struct source_location location;
	struct type_descriptor *lhs_type;
	struct type_descriptor *rhs_type;
};

struct unreachable_data {
	struct source_location location;
};

struct invalid_value_data {
	struct source_location location;
	struct type_descriptor *type;
};

#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
typedef __int128 s_max;
typedef unsigned __int128 u_max;
#else
typedef s64 s_max;
typedef u64 u_max;
#endif

#endif
back to top