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| author | Amir Goldstein <amir73il@gmail.com> | 2018-01-03 19:34:45 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-01-24 10:18:19 +0100 |
| commit | 9678e630305724487f1fc101d6b83c383ff9cc90 (patch) | |
| tree | 553bc1c4c744236395c6eb0613b69fab1d4903b6 | |
| parent | a5a927a7c82e28ea76599dee4019c41e372c911f (diff) | |
| download | linux-9678e630305724487f1fc101d6b83c383ff9cc90.tar.bz2 | |
ovl: fix inconsistent d_ino for legacy merge dir
For a merge dir that was copied up before v4.12 or that was hand crafted
offline (e.g. mkdir {upper/lower}/dir), upper dir does not contain the
'trusted.overlay.origin' xattr. In that case, stat(2) on the merge dir
returns the lower dir st_ino, but getdents(2) returns the upper dir d_ino.
After this change, on merge dir lookup, missing origin xattr on upper
dir will be fixed and 'impure' xattr will be fixed on parent of the legacy
merge dir.
Suggested-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| -rw-r--r-- | fs/overlayfs/copy_up.c | 4 | ||||
| -rw-r--r-- | fs/overlayfs/namei.c | 33 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 2 |
3 files changed, 37 insertions, 2 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index eb3b8d39fb61..206ececd5ae7 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -288,8 +288,8 @@ out: return fh; } -static int ovl_set_origin(struct dentry *dentry, struct dentry *lower, - struct dentry *upper) +int ovl_set_origin(struct dentry *dentry, struct dentry *lower, + struct dentry *upper) { const struct ovl_fh *fh = NULL; int err; diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 69a43ede0a2a..69f4f19659fc 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -584,6 +584,27 @@ static int ovl_find_layer(struct ovl_fs *ofs, struct ovl_path *path) return i; } +/* Fix missing 'origin' xattr */ +static int ovl_fix_origin(struct dentry *dentry, struct dentry *lower, + struct dentry *upper) +{ + int err; + + if (ovl_check_origin_xattr(upper)) + return 0; + + err = ovl_want_write(dentry); + if (err) + return err; + + err = ovl_set_origin(dentry, lower, upper); + if (!err) + err = ovl_set_impure(dentry->d_parent, upper->d_parent); + + ovl_drop_write(dentry); + return err; +} + struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { @@ -674,6 +695,18 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, if (!this) continue; + /* + * If no origin fh is stored in upper of a merge dir, store fh + * of lower dir and set upper parent "impure". + */ + if (upperdentry && !ctr && !ofs->noxattr) { + err = ovl_fix_origin(dentry, this, upperdentry); + if (err) { + dput(this); + goto out_put; + } + } + stack[ctr].dentry = this; stack[ctr].layer = lower.layer; ctr++; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index b489099ccd49..d1cfa69c98b5 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -322,3 +322,5 @@ int ovl_copy_up_flags(struct dentry *dentry, int flags); int ovl_copy_xattr(struct dentry *old, struct dentry *new); int ovl_set_attr(struct dentry *upper, struct kstat *stat); struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper); +int ovl_set_origin(struct dentry *dentry, struct dentry *lower, + struct dentry *upper); |