dax: move writeback calls into the filesystems
Previously calls to dax_writeback_mapping_range() for all DAX filesystems
(ext2, ext4 & xfs) were centralized in filemap_write_and_wait_range().
dax_writeback_mapping_range() needs a struct block_device, and it used
to get that from inode->i_sb->s_bdev. This is correct for normal inodes
mounted on ext2, ext4 and XFS filesystems, but is incorrect for DAX raw
block devices and for XFS real-time files.
Instead, call dax_writeback_mapping_range() directly from the filesystem
->writepages function so that it can supply us with a valid block
device. This also fixes DAX code to properly flush caches in response
to sync(2).
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
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>
diff --git a/mm/filemap.c b/mm/filemap.c
index 23edcce..3461d97 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -446,7 +446,8 @@
{
int err = 0;
- if (mapping->nrpages) {
+ if ((!dax_mapping(mapping) && mapping->nrpages) ||
+ (dax_mapping(mapping) && mapping->nrexceptional)) {
err = filemap_fdatawrite(mapping);
/*
* Even if the above returned error, the pages may be
@@ -482,13 +483,8 @@
{
int err = 0;
- if (dax_mapping(mapping) && mapping->nrexceptional) {
- err = dax_writeback_mapping_range(mapping, lstart, lend);
- if (err)
- return err;
- }
-
- if (mapping->nrpages) {
+ if ((!dax_mapping(mapping) && mapping->nrpages) ||
+ (dax_mapping(mapping) && mapping->nrexceptional)) {
err = __filemap_fdatawrite_range(mapping, lstart, lend,
WB_SYNC_ALL);
/* See comment of filemap_write_and_wait() */