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-rw-r--r--fs/overlayfs/util.c103
1 files changed, 80 insertions, 23 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index f48284a2a896..87f811c089e4 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -194,6 +194,20 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path)
return type;
}
+enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path)
+{
+ enum ovl_path_type type = ovl_path_type(dentry);
+
+ WARN_ON_ONCE(d_is_dir(dentry));
+
+ if (!OVL_TYPE_UPPER(type) || OVL_TYPE_MERGE(type))
+ ovl_path_lowerdata(dentry, path);
+ else
+ ovl_path_upper(dentry, path);
+
+ return type;
+}
+
struct dentry *ovl_dentry_upper(struct dentry *dentry)
{
return ovl_upperdentry_dereference(OVL_I(d_inode(dentry)));
@@ -236,6 +250,17 @@ struct dentry *ovl_i_dentry_upper(struct inode *inode)
return ovl_upperdentry_dereference(OVL_I(inode));
}
+void ovl_i_path_real(struct inode *inode, struct path *path)
+{
+ path->dentry = ovl_i_dentry_upper(inode);
+ if (!path->dentry) {
+ path->dentry = OVL_I(inode)->lowerpath.dentry;
+ path->mnt = OVL_I(inode)->lowerpath.layer->mnt;
+ } else {
+ path->mnt = ovl_upper_mnt(OVL_FS(inode->i_sb));
+ }
+}
+
struct inode *ovl_inode_upper(struct inode *inode)
{
struct dentry *upperdentry = ovl_i_dentry_upper(inode);
@@ -245,7 +270,9 @@ struct inode *ovl_inode_upper(struct inode *inode)
struct inode *ovl_inode_lower(struct inode *inode)
{
- return OVL_I(inode)->lower;
+ struct dentry *lowerdentry = OVL_I(inode)->lowerpath.dentry;
+
+ return lowerdentry ? d_inode(lowerdentry) : NULL;
}
struct inode *ovl_inode_real(struct inode *inode)
@@ -443,7 +470,7 @@ static void ovl_dir_version_inc(struct dentry *dentry, bool impurity)
void ovl_dir_modified(struct dentry *dentry, bool impurity)
{
/* Copy mtime/ctime */
- ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
+ ovl_copyattr(d_inode(dentry));
ovl_dir_version_inc(dentry, impurity);
}
@@ -466,6 +493,7 @@ bool ovl_is_whiteout(struct dentry *dentry)
struct file *ovl_path_open(struct path *path, int flags)
{
struct inode *inode = d_inode(path->dentry);
+ struct user_namespace *real_mnt_userns = mnt_user_ns(path->mnt);
int err, acc_mode;
if (flags & ~(O_ACCMODE | O_LARGEFILE))
@@ -482,12 +510,12 @@ struct file *ovl_path_open(struct path *path, int flags)
BUG();
}
- err = inode_permission(&init_user_ns, inode, acc_mode | MAY_OPEN);
+ err = inode_permission(real_mnt_userns, inode, acc_mode | MAY_OPEN);
if (err)
return ERR_PTR(err);
/* O_NOATIME is an optimization, don't fail if not permitted */
- if (inode_owner_or_capable(&init_user_ns, inode))
+ if (inode_owner_or_capable(real_mnt_userns, inode))
flags |= O_NOATIME;
return dentry_open(path, flags, current_cred());
@@ -550,11 +578,11 @@ void ovl_copy_up_end(struct dentry *dentry)
ovl_inode_unlock(d_inode(dentry));
}
-bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry)
+bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, struct path *path)
{
int res;
- res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_ORIGIN, NULL, 0);
+ res = ovl_path_getxattr(ofs, path, OVL_XATTR_ORIGIN, NULL, 0);
/* Zero size value means "copied up but origin unknown" */
if (res >= 0)
@@ -563,16 +591,16 @@ bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry)
return false;
}
-bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
- enum ovl_xattr ox)
+bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, struct path *path,
+ enum ovl_xattr ox)
{
int res;
char val;
- if (!d_is_dir(dentry))
+ if (!d_is_dir(path->dentry))
return false;
- res = ovl_do_getxattr(OVL_FS(sb), dentry, ox, &val, 1);
+ res = ovl_path_getxattr(ofs, path, ox, &val, 1);
if (res == 1 && val == 'y')
return true;
@@ -612,7 +640,7 @@ int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
if (ofs->noxattr)
return xerr;
- err = ovl_do_setxattr(ofs, upperdentry, ox, value, size);
+ err = ovl_setxattr(ofs, upperdentry, ox, value, size);
if (err == -EOPNOTSUPP) {
pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox));
@@ -652,8 +680,8 @@ void ovl_check_protattr(struct inode *inode, struct dentry *upper)
char buf[OVL_PROTATTR_MAX+1];
int res, n;
- res = ovl_do_getxattr(ofs, upper, OVL_XATTR_PROTATTR, buf,
- OVL_PROTATTR_MAX);
+ res = ovl_getxattr_upper(ofs, upper, OVL_XATTR_PROTATTR, buf,
+ OVL_PROTATTR_MAX);
if (res < 0)
return;
@@ -708,7 +736,7 @@ int ovl_set_protattr(struct inode *inode, struct dentry *upper,
err = ovl_check_setxattr(ofs, upper, OVL_XATTR_PROTATTR,
buf, len, -EPERM);
} else if (inode->i_flags & OVL_PROT_I_FLAGS_MASK) {
- err = ovl_do_removexattr(ofs, upper, OVL_XATTR_PROTATTR);
+ err = ovl_removexattr(ofs, upper, OVL_XATTR_PROTATTR);
if (err == -EOPNOTSUPP || err == -ENODATA)
err = 0;
}
@@ -824,7 +852,7 @@ static void ovl_cleanup_index(struct dentry *dentry)
}
inode_lock_nested(dir, I_MUTEX_PARENT);
- index = lookup_one_len(name.name, indexdir, name.len);
+ index = ovl_lookup_upper(ofs, name.name, indexdir, name.len);
err = PTR_ERR(index);
if (IS_ERR(index)) {
index = NULL;
@@ -834,7 +862,7 @@ static void ovl_cleanup_index(struct dentry *dentry)
dir, index);
} else {
/* Cleanup orphan index entries */
- err = ovl_cleanup(dir, index);
+ err = ovl_cleanup(ofs, dir, index);
}
inode_unlock(dir);
@@ -943,15 +971,15 @@ err:
}
/* err < 0, 0 if no metacopy xattr, 1 if metacopy xattr found */
-int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry)
+int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct path *path)
{
int res;
/* Only regular files can have metacopy xattr */
- if (!S_ISREG(d_inode(dentry)->i_mode))
+ if (!S_ISREG(d_inode(path->dentry)->i_mode))
return 0;
- res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_METACOPY, NULL, 0);
+ res = ovl_path_getxattr(ofs, path, OVL_XATTR_METACOPY, NULL, 0);
if (res < 0) {
if (res == -ENODATA || res == -EOPNOTSUPP)
return 0;
@@ -987,13 +1015,12 @@ bool ovl_is_metacopy_dentry(struct dentry *dentry)
return (oe->numlower > 1);
}
-char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
- int padding)
+char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct path *path, int padding)
{
int res;
char *s, *next, *buf = NULL;
- res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, NULL, 0);
+ res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, NULL, 0);
if (res == -ENODATA || res == -EOPNOTSUPP)
return NULL;
if (res < 0)
@@ -1005,7 +1032,7 @@ char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
if (!buf)
return ERR_PTR(-ENOMEM);
- res = ovl_do_getxattr(ofs, dentry, OVL_XATTR_REDIRECT, buf, res);
+ res = ovl_path_getxattr(ofs, path, OVL_XATTR_REDIRECT, buf, res);
if (res < 0)
goto fail;
if (res == 0)
@@ -1060,3 +1087,33 @@ int ovl_sync_status(struct ovl_fs *ofs)
return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
}
+
+/*
+ * ovl_copyattr() - copy inode attributes from layer to ovl inode
+ *
+ * When overlay copies inode information from an upper or lower layer to the
+ * relevant overlay inode it will apply the idmapping of the upper or lower
+ * layer when doing so ensuring that the ovl inode ownership will correctly
+ * reflect the ownership of the idmapped upper or lower layer. For example, an
+ * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to
+ * map any lower or upper inode owned by id 1001 to id 1000. These mapping
+ * helpers are nops when the relevant layer isn't idmapped.
+ */
+void ovl_copyattr(struct inode *inode)
+{
+ struct path realpath;
+ struct inode *realinode;
+ struct user_namespace *real_mnt_userns;
+
+ ovl_i_path_real(inode, &realpath);
+ realinode = d_inode(realpath.dentry);
+ real_mnt_userns = mnt_user_ns(realpath.mnt);
+
+ inode->i_uid = i_uid_into_mnt(real_mnt_userns, realinode);
+ inode->i_gid = i_gid_into_mnt(real_mnt_userns, realinode);
+ inode->i_mode = realinode->i_mode;
+ inode->i_atime = realinode->i_atime;
+ inode->i_mtime = realinode->i_mtime;
+ inode->i_ctime = realinode->i_ctime;
+ i_size_write(inode, i_size_read(realinode));
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-03 04:54:52 +0000