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author | Miklos Szeredi <mszeredi@redhat.com> | 2016-12-16 11:02:56 +0100 |
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committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-12-16 11:02:56 +0100 |
commit | a6c6065511411c57167a6cdae0c33263fb662b51 (patch) | |
tree | cd2c7904884c557a0d7d26a88efc737a8885407a /fs/overlayfs/super.c | |
parent | 02b69b284cd7815239fabfe895bfef9a9eb5a3ce (diff) | |
download | linux-stable-a6c6065511411c57167a6cdae0c33263fb662b51.tar.gz linux-stable-a6c6065511411c57167a6cdae0c33263fb662b51.tar.bz2 linux-stable-a6c6065511411c57167a6cdae0c33263fb662b51.zip |
ovl: redirect on rename-dir
Current code returns EXDEV when a directory would need to be copied up to
move. We could copy up the directory tree in this case, but there's
another, simpler solution: point to old lower directory from moved upper
directory.
This is achieved with a "trusted.overlay.redirect" xattr storing the path
relative to the root of the overlay. After such attribute has been set,
the directory can be moved without further actions required.
This is a backward incompatible feature, old kernels won't be able to
correctly mount an overlay containing redirected directories.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 4e44e865b716..520f9ab0e9ef 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -226,6 +226,8 @@ enum { OPT_UPPERDIR, OPT_WORKDIR, OPT_DEFAULT_PERMISSIONS, + OPT_REDIRECT_DIR_ON, + OPT_REDIRECT_DIR_OFF, OPT_ERR, }; @@ -234,6 +236,8 @@ static const match_table_t ovl_tokens = { {OPT_UPPERDIR, "upperdir=%s"}, {OPT_WORKDIR, "workdir=%s"}, {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, + {OPT_REDIRECT_DIR_ON, "redirect_dir=on"}, + {OPT_REDIRECT_DIR_OFF, "redirect_dir=off"}, {OPT_ERR, NULL} }; @@ -298,6 +302,14 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) config->default_permissions = true; break; + case OPT_REDIRECT_DIR_ON: + config->redirect_dir = true; + break; + + case OPT_REDIRECT_DIR_OFF: + config->redirect_dir = false; + break; + default: pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); return -EINVAL; |