Signed-off-by: zhangyi (F) <yi.zhang@xxxxxxxxxx>
---
README.md | 56 +++++++++++++++++++++++++++++++++-----------------------
1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/README.md b/README.md
index 8de69cd..1d759b0 100644
--- a/README.md
+++ b/README.md
@@ -20,11 +20,12 @@ Opaque directories
------------------
An opaque directory is a directory with "trusted.overlay.opaque" xattr valued
-"y". There are two legal situations of making opaque directory: 1) create
-directory over whiteout 2) creat directory in merged directory. If an opaque
-directory is found, corresponding matching name in lower layers might exist or
-parent directory might merged, If not, the opaque xattr will be treated as
-invalid and remove.
+"y". There are two legal situations of making opaque directory:
+1) Create directory over whiteout,
+2) Creat directory in merged directory.
+If an opaque directory is found, either corresponding matching name in lower
+layers is exist or parent directory is merged, If not, the opaque xattr will be
+treated as invalid and remove.
Redirect directories
@@ -35,17 +36,21 @@ valued to the path of the original location from the root of the overlay. It
is only used when renaming a directory and "redirect dir" feature is enabled.
If an redirect directory is found, the following must be met:
-1) The directory store in redirect xattr should exist in one of lower layers.
+1) The directory path pointed by redirect xattr should exist in one of lower
+ layers.
2) The origin directory should be redirected only once in one layer, which mean
there is only one redirect xattr point to this origin directory in the
specified layer.
-3) A whiteout or an opaque directory with the same name to origin should exist
- in the same directory as the redirect directory.
+3) A whiteout or an opaque directory or another redirect directory with the
+ same name to origin should exist in the same directory as the redirect
+ directory.
If not, 1) The redirect xattr is invalid and need to remove 2) One of the
-redirect xattr is redundant but not sure which one is, ask user 3) Create a
-whiteout device or set opaque xattr to an existing directory if the parent
-directory was meregd or remove xattr if not.
+redirect xattr is redundant but not sure which one is, ask user by default or
+remove in 'yes' mode 3) Check and fix the missing whiteout or opaque in redierct
+parent directory if there is no another redirected upper directory covering the
+redirect lower target.
+
Usage
=====
@@ -58,14 +63,17 @@ Usage
fsck.overlay [-l lowerdir] [-u upperdir] [-w workdir] [-avhV]
Options:
- -l, --lowerdir=LOWERDIR specify lower directories of overlayfs,
- multiple lower use ':' as separator.
- -u, --upperdir=UPPERDIR specify upper directory of overlayfs
- -w, --workdir=WORKDIR specify work directory of overlayfs
- -a, --auto repair automatically (no questions)
- -v, --verbose print more messages of overlayfs
- -h, --help display this usage of overlayfs
- -V, --version display version information
+ -l, --lowerdir=LOWERDIR specify lower directories of overlayfs,
+ multiple lower use ':' as separator,
+ the leftmost one is the toppest
+ -u, --upperdir=UPPERDIR specify upper directory of overlayfs
+ -w, --workdir=WORKDIR specify work directory of overlayfs
+ -p, automatic repair (no questions)
+ -n, make no changes to the filesystem
+ -y, assume "yes" to all questions
+ -v, --verbose print more messages of overlayfs
+ -h, --help display this usage of overlayfs
+ -V, --version display version information
3. Exit value:
0 No errors
@@ -82,7 +90,9 @@ Todo
1. Overlay filesystem mounted check. Prevent fscking when overlay is
online. Now, We cannot distinguish mounted directories if overlayfs was
- mounted with relative path.
-2. Symbolic link check.
-3. Check origin/impure/nlink xattr.
-4. ...
+ mounted with relative path. Should modify kernel together to support.
+2. Check and fix invalid redirect xattr through origin xattr.
+3. Symbolic link check.
+4. Check origin/impure/nlink xattr.
+5. Check index feature consistency.
+6. ...
--
2.9.5
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