On Wed 30-08-17 12:44:03, Dan Williams wrote: > The ->iomap_begin() operation is a hot path, so cache the > fs_dax_get_by_host() result at mount time to avoid the incurring the > hash lookup overhead on a per-i/o basis. > > Cc: "Theodore Ts'o" <tytso@xxxxxxx> > Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx> > Cc: Jan Kara <jack@xxxxxxx> > Reported-by: Christoph Hellwig <hch@xxxxxx> > Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Looks good to me (and it looks even cleaner than your previous approach). Just one nit below. You can add: Reviewed-by: Jan Kara <jack@xxxxxxx> > diff --git a/fs/ext2/super.c b/fs/ext2/super.c > index 7b1bc9059863..d9dd999568c2 100644 > --- a/fs/ext2/super.c > +++ b/fs/ext2/super.c > @@ -144,6 +144,7 @@ static void ext2_put_super (struct super_block * sb) > int db_count; > int i; > struct ext2_sb_info *sbi = EXT2_SB(sb); > + struct dax_device *dax_dev = sbi->s_daxdev; > > ext2_quota_off_umount(sb); > > @@ -172,6 +173,7 @@ static void ext2_put_super (struct super_block * sb) > sb->s_fs_info = NULL; > kfree(sbi->s_blockgroup_lock); > kfree(sbi); > + fs_put_dax(dax_dev); The local variable looks superfluous here. I'd just do fs_put_dax(sbi->s_daxdev); Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
