From: Yuriy Belikov Date: Wed, 4 Sep 2024 16:54:29 +0000 (+0300) Subject: overlayfs.rst: update metacopy section in overlayfs documentation X-Git-Tag: v6.12-rc1~142^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=930b7c32ea2b514fb2c37aa3d4b946d954ee7fa2;p=thirdparty%2Fkernel%2Flinux.git overlayfs.rst: update metacopy section in overlayfs documentation - Provide info about trusted.overlay.metacopy extended attribute - Minor rephrasing regarding copy-up operation with metacopy=on Signed-off-by: Yuriy Belikov Signed-off-by: Amir Goldstein --- diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index 1655144014418..3436447123409 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -367,8 +367,11 @@ Metadata only copy up When the "metacopy" feature is enabled, overlayfs will only copy up metadata (as opposed to whole file), when a metadata specific operation -like chown/chmod is performed. Full file will be copied up later when -file is opened for WRITE operation. +like chown/chmod is performed. An upper file in this state is marked with +"trusted.overlayfs.metacopy" xattr which indicates that the upper file +contains no data. The data will be copied up later when file is opened for +WRITE operation. After the lower file's data is copied up, +the "trusted.overlayfs.metacopy" xattr is removed from the upper file. In other words, this is delayed data copy up operation and data is copied up when there is a need to actually modify data.