Vivek Goyal c86243b090 ovl: provide a mount option "volatile" ... Container folks are complaining that dnf/yum issues too many sync while installing packages and this slows down the image build. Build requirement is such that they don't care if a node goes down while build was still going on. In that case, they will simply throw away unfinished layer and start new build. So they don't care about syncing intermediate state to the disk and hence don't want to pay the price associated with sync. So they are asking for mount options where they can disable sync on overlay mount point. They primarily seem to have two use cases. - For building images, they will mount overlay with nosync and then sync upper layer after unmounting overlay and reuse upper as lower for next layer. - For running containers, they don't seem to care about syncing upper layer because if node goes down, they will simply throw away upper layer and create a fresh one. So this patch provides a mount option "volatile" which disables all forms of sync. Now it is caller's responsibility to throw away upper if system crashes or shuts down and start fresh. With "volatile", I am seeing roughly 20% speed up in my VM where I am just installing emacs in an image. Installation time drops from 31 seconds to 25 seconds when nosync option is used. This is for the case of building on top of an image where all packages are already cached. That way I take out the network operations latency out of the measurement. Giuseppe is also looking to cut down on number of iops done on the disk. He is complaining that often in cloud their VMs are throttled if they cross the limit. This option can help them where they reduce number of iops (by cutting down on frequent sync and writebacks). Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>		2020-09-02 10:58:48 +02:00
..
caching	docs: filesystems: Replace HTTP links with HTTPS ones	2020-07-13 09:33:22 -06:00
cifs	docs: filesystems: convert cifs/cifsroot.txt to ReST	2020-05-05 09:22:21 -06:00
ext4	ext4: replace HTTP links with HTTPS ones	2020-08-06 01:01:57 -04:00
nfs	Replace HTTP links with HTTPS ones: Documentation/filesystems	2020-06-26 11:14:12 -06:00
spufs	docs: filesystems: convert spufs/spu_run.txt to ReST	2020-05-05 09:22:24 -06:00
9p.rst	Replace HTTP links with HTTPS ones: 9P FILE SYSTEM	2020-07-13 11:28:12 -06:00
adfs.rst	docs: filesystems: convert adfs.txt to ReST	2020-03-02 13:58:44 -07:00
affs.rst	docs: filesystems: convert affs.txt to ReST	2020-03-02 14:01:06 -07:00
afs.rst	Replace HTTP links with HTTPS ones: AFS FILESYSTEM	2020-07-13 11:25:29 -06:00
api-summary.rst	docs: no structured comments in fs/file_table.c	2019-05-24 15:03:39 -06:00
autofs-mount-control.rst	Documentation: filesystems: autofs-mount-control: drop doubled words	2020-07-05 14:44:29 -06:00
autofs.rst	docs: filesystems: Add mount map description in Content	2019-11-18 12:19:59 -07:00
automount-support.rst	docs: filesystems: convert automount-support.txt to ReST	2020-05-05 09:22:21 -06:00
befs.rst	docs: filesystems: convert befs.txt to ReST	2020-03-02 14:01:25 -07:00
bfs.rst	docs: filesystems: convert bfs.txt to ReST	2020-03-02 14:01:26 -07:00
btrfs.rst	docs: filesystems: convert btrfs.txt to ReST	2020-03-02 14:01:28 -07:00
ceph.rst	The main items are:	2020-04-08 21:44:05 -07:00
coda.rst	Documentation: coda: annotate duplicated words	2020-07-13 10:02:32 -06:00
configfs.rst	Documentation: filesystems: configfs: drop doubled word	2020-07-05 14:44:29 -06:00
cramfs.rst	docs: filesystems: convert cramfs.txt to ReST	2020-03-02 14:02:07 -07:00
dax.txt	This is the second round of ext4 commits for 5.8 merge window. It	2020-06-15 09:32:10 -07:00
debugfs.rst	debugfs: make sure we can remove u32_array files cleanly	2020-07-10 13:54:00 -07:00
devpts.rst	docs: filesystems: convert devpts.txt to ReST	2020-05-05 09:22:21 -06:00
directory-locking.rst	Documentation: filesystems: directory-locking: drop doubled word	2020-07-05 14:44:29 -06:00
dlmfs.rst	ocfs2: replace HTTP links with HTTPS ones	2020-08-07 11:33:22 -07:00
dnotify.rst	docs: filesystems: convert dnotify.txt to ReST	2020-05-05 09:22:22 -06:00
ecryptfs.rst	docs: prevent warnings due to autosectionlabel	2020-03-20 17:01:29 -06:00
efivarfs.rst	docs: filesystems: add info about efivars content	2020-05-25 18:59:59 -06:00
erofs.rst	docs: filesystems: convert erofs.txt to ReST	2020-03-02 14:02:57 -07:00
ext2.rst	docs: filesystems: convert ext2.txt to ReST	2020-03-02 14:02:59 -07:00
ext3.rst	docs: filesystems: convert ext3.txt to ReST	2020-03-02 14:03:16 -07:00
f2fs.rst	f2fs-for-5.9-rc1	2020-08-10 18:33:22 -07:00
fiemap.rst	A lot of bug fixes and cleanups for ext4, including:	2020-06-05 16:19:28 -07:00
files.rst	docs: filesystems: convert files.txt to ReST	2020-05-05 09:22:22 -06:00
fscrypt.rst	fscrypt: document inline encryption support	2020-07-27 09:18:49 -07:00
fsverity.rst	Documentation: filesystems: fsverity: drop doubled word	2020-07-05 14:44:29 -06:00
fuse-io.rst	docs: filesystems: convert fuse-io.txt to ReST	2020-05-05 09:22:22 -06:00
fuse.rst	docs: filesystems: fuse.rst: supress a Sphinx warning	2020-03-10 11:55:25 -06:00
gfs2-glocks.rst	docs: filesystems: convert gfs2-glocks.txt to ReST	2020-06-02 19:45:05 +02:00
gfs2-uevents.rst	docs: filesystems: convert gfs2-uevents.txt to ReST	2020-03-02 14:03:35 -07:00
gfs2.rst	docs: filesystems: convert gfs2.txt to ReST	2020-03-02 14:03:18 -07:00
hfs.rst	Replace HTTP links with HTTPS ones: Documentation/filesystems	2020-06-26 11:14:12 -06:00
hfsplus.rst	docs: filesystems: convert hfsplus.txt to ReST	2020-03-02 14:03:47 -07:00
hpfs.rst	Replace HTTP links with HTTPS ones: Documentation/filesystems	2020-06-26 11:14:12 -06:00
index.rst	Changes in gfs2:	2020-06-08 12:47:09 -07:00
inotify.rst	docs: filesystems: convert inotify.txt to ReST	2020-03-02 14:03:55 -07:00
isofs.rst	docs: filesystems: convert isofs.txt to ReST	2020-03-02 14:04:06 -07:00
journalling.rst	Filesystems: Documentation: Replace deprecated :c:func: Usage	2020-08-11 10:23:27 -06:00
locking.rst	It's been a busy cycle for documentation - hopefully the busiest for a	2020-08-04 22:47:54 -07:00
locks.rst	docs: filesystems: convert mandatory-locking.txt to ReST	2020-05-05 09:22:22 -06:00
mandatory-locking.rst	docs: filesystems: convert mandatory-locking.txt to ReST	2020-05-05 09:22:22 -06:00
mount_api.rst	Documentation: filesystems: mount_api: drop doubled word	2020-07-05 14:44:29 -06:00
nilfs2.rst	docs: filesystems: convert nilfs2.txt to ReST	2020-03-02 14:04:06 -07:00
ntfs.rst	docs: filesystems: convert ntfs.txt to ReST	2020-03-02 14:04:06 -07:00
ocfs2-online-filecheck.rst	docs: filesystems: convert ocfs2-online-filecheck.txt to ReST	2020-03-02 14:04:06 -07:00
ocfs2.rst	ocfs2: replace HTTP links with HTTPS ones	2020-08-07 11:33:22 -07:00
omfs.rst	Replace HTTP links with HTTPS ones: OMFS	2020-07-13 11:24:43 -06:00
orangefs.rst	docs: orangefs: fix pvfs2tab literal block	2020-04-28 12:35:47 -06:00
overlayfs.rst	ovl: provide a mount option "volatile"	2020-09-02 10:58:48 +02:00
path-lookup.rst	docs: path-lookup: markup fixes for emphasis	2020-07-27 16:14:13 -06:00
path-lookup.txt	Replace HTTP links with HTTPS ones: documentation	2020-06-08 09:30:19 -06:00
porting.rst	ovl: make private mounts longterm	2020-06-04 10:48:19 +02:00
proc.rst	doc, mm: clarify /proc/<pid>/oom_score value range	2020-08-12 10:57:56 -07:00
qnx6.rst	docs: filesystems: fix typo in qnx6.rst	2020-04-07 13:20:56 -06:00
quota.rst	quota: Fixup http links in quota doc	2020-07-09 08:14:01 +02:00
ramfs-rootfs-initramfs.rst	Replace HTTP links with HTTPS ones: Documentation/filesystems	2020-06-26 11:14:12 -06:00
relay.rst	docs: filesystems: convert relay.txt to ReST	2020-03-02 14:04:41 -07:00
romfs.rst	docs: filesystems: convert romfs.txt to ReST	2020-03-02 14:04:41 -07:00
seq_file.rst	Replace HTTP links with HTTPS ones: documentation	2020-06-08 09:30:19 -06:00
sharedsubtree.rst	docs: filesystems: convert sharedsubtree.txt to ReST	2020-05-05 09:22:23 -06:00
splice.rst
squashfs.rst	docs: filesystems: convert squashfs.txt to ReST	2020-03-02 14:04:41 -07:00
sysfs-pci.rst	PCI: correct flag name	2020-07-27 16:21:04 -06:00
sysfs-tagging.rst	Documentation: filesystems: sysfs-tagging: drop doubled word	2020-07-05 14:44:30 -06:00
sysfs.rst	docs: filesystems: fix renamed references	2020-04-20 15:45:22 -06:00
sysv-fs.rst	docs: filesystems: convert sysv-fs.txt to ReST	2020-03-02 14:04:41 -07:00
tmpfs.rst	tmpfs: support 64-bit inums per-sb	2020-08-07 11:33:24 -07:00
ubifs-authentication.rst	Replace HTTP links with HTTPS ones: Documentation/filesystems	2020-06-26 11:14:12 -06:00
ubifs.rst	docs: filesystems: convert ubifs.txt to ReST	2020-03-02 14:04:41 -07:00
udf.rst	udf: Replace HTTP links with HTTPS ones	2020-07-14 14:37:39 +02:00
vfat.rst	Documentation: filesystems: convert vfat.txt to RST	2020-01-10 10:58:45 -07:00
vfs.rst	docs: filesystems: vfs: correct flag name	2020-07-27 16:19:51 -06:00
virtiofs.rst	virtiofs: Add mount option and atime behavior to the doc	2020-04-20 17:01:34 +02:00
xfs-delayed-logging-design.rst	docs: filesystems: convert xfs-delayed-logging-design.txt to ReST	2020-05-05 09:22:24 -06:00
xfs-self-describing-metadata.rst	New code for 5.8:	2020-06-02 19:21:40 -07:00
zonefs.rst	zonefs: update documentation to reflect zone size vs capacity	2020-08-11 17:42:25 +09:00