Jiufei Xue 2406a307ac ovl: implement async IO routines ... A performance regression was observed since linux v4.19 with aio test using fio with iodepth 128 on overlayfs. The queue depth of the device was always 1 which is unexpected. After investigation, it was found that commit 16914e6fc7 ("ovl: add ovl_read_iter()") and commit 2a92e07edc ("ovl: add ovl_write_iter()") resulted in vfs_iter_{read,write} being called on underlying filesystem, which always results in syncronous IO. Implement async IO for stacked reading and writing. This resolves the performance regresion. This is implemented by allocating a new kiocb for submitting the AIO request on the underlying filesystem. When the request is completed, the new kiocb is freed and the completion callback is called on the original iocb. Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>		2020-01-24 09:46:46 +01:00
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copy_up.c	ovl: improving copy-up efficiency for big sparse file	2020-01-22 20:11:41 +01:00
dir.c	ovl: use pr_fmt auto generate prefix	2020-01-22 20:11:41 +01:00
export.c	ovl: layer is const	2020-01-24 09:46:45 +01:00
file.c	ovl: implement async IO routines	2020-01-24 09:46:46 +01:00
inode.c	ovl: fix corner case of non-constant st_dev;st_ino	2020-01-24 09:46:45 +01:00
Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
namei.c	ovl: generalize the lower_layers[] array	2020-01-22 20:11:41 +01:00
overlayfs.h	ovl: implement async IO routines	2020-01-24 09:46:46 +01:00
ovl_entry.h	ovl: layer is const	2020-01-24 09:46:45 +01:00
readdir.c	ovl: layer is const	2020-01-24 09:46:45 +01:00
super.c	ovl: implement async IO routines	2020-01-24 09:46:46 +01:00
util.c	ovl: layer is const	2020-01-24 09:46:45 +01:00