ovl: update Kconfig texts

Add some hints about overlayfs kernel config options.

Enabling NFS export by default is especially recommended against, as it
incurs a performance penalty even if the filesystem is not actually
exported.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2018-03-07 11:47:15 +01:00
parent d1fe96c0e4
commit 36cd95dfa1

View File

@ -24,6 +24,8 @@ config OVERLAY_FS_REDIRECT_DIR
an overlay which has redirects on a kernel that doesn't support this
feature will have unexpected results.
If unsure, say N.
config OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW
bool "Overlayfs: follow redirects even if redirects are turned off"
default y
@ -32,8 +34,13 @@ config OVERLAY_FS_REDIRECT_ALWAYS_FOLLOW
Disable this to get a possibly more secure configuration, but that
might not be backward compatible with previous kernels.
If backward compatibility is not an issue, then it is safe and
recommended to say N here.
For more information, see Documentation/filesystems/overlayfs.txt
If unsure, say Y.
config OVERLAY_FS_INDEX
bool "Overlayfs: turn on inodes index feature by default"
depends on OVERLAY_FS
@ -51,6 +58,8 @@ config OVERLAY_FS_INDEX
That is, mounting an overlay which has an inodes index on a kernel
that doesn't support this feature will have unexpected results.
If unsure, say N.
config OVERLAY_FS_NFS_EXPORT
bool "Overlayfs: turn on NFS export feature by default"
depends on OVERLAY_FS
@ -72,3 +81,8 @@ config OVERLAY_FS_NFS_EXPORT
Note, that the NFS export feature is not backward compatible.
That is, mounting an overlay which has a full index on a kernel
that doesn't support this feature will have unexpected results.
Most users should say N here and enable this feature on a case-by-
case basis with the "nfs_export=on" mount option.
Say N unless you fully understand the consequences.