From 21a228781104ae6fed7e720137ab024575071feb Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il@gmail.com>
Date: Wed, 17 May 2017 00:12:41 +0300
Subject: [PATCH] ovl: handle rename when upper doesn't support xattr
On failure to set opaque/redirect xattr on rename, skip setting xattr and
return -EXDEV.
On failure to set opaque xattr when creating a new directory, -EIO is
returned instead of -EOPNOTSUPP.
Any failure to set those xattr will be recorded in super block and
then setting any xattr on upper won't be attempted again.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/overlayfs/dir.c | 29 +++++++++++++++++++----------
fs/overlayfs/overlayfs.h | 1 -
fs/overlayfs/util.c | 9 +--------
3 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 723b98b9069876..80e0e202a346ed 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -127,17 +127,28 @@ int ovl_create_real(struct inode *dir, struct dentry *newdentry,
return err;
}
-static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
+static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
+ int xerr)
{
int err;
- err = ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
+ err = ovl_check_setxattr(dentry, upper, OVL_XATTR_OPAQUE, "y", 1, xerr);
if (!err)
ovl_dentry_set_opaque(dentry);
return err;
}
+static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry)
+{
+ /*
+ * Fail with -EIO when trying to create opaque dir and upper doesn't
+ * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to
+ * return a specific error for noxattr case.
+ */
+ return ovl_set_opaque_xerr(dentry, upperdentry, -EIO);
+}
+
/* Common operations required to be done after creation of file on upper */
static void ovl_instantiate(struct dentry *dentry, struct inode *inode,
struct dentry *newdentry, bool hardlink)
@@ -846,18 +857,16 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir)
if (IS_ERR(redirect))
return PTR_ERR(redirect);
- err = ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_REDIRECT,
- redirect, strlen(redirect), 0);
+ err = ovl_check_setxattr(dentry, ovl_dentry_upper(dentry),
+ OVL_XATTR_REDIRECT,
+ redirect, strlen(redirect), -EXDEV);
if (!err) {
spin_lock(&dentry->d_lock);
ovl_dentry_set_redirect(dentry, redirect);
spin_unlock(&dentry->d_lock);
} else {
kfree(redirect);
- if (err == -EOPNOTSUPP)
- ovl_clear_redirect_dir(dentry->d_sb);
- else
- pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err);
+ pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err);
/* Fall back to userspace copy-up */
err = -EXDEV;
}
@@ -992,7 +1001,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
if (ovl_type_merge_or_lower(old))
err = ovl_set_redirect(old, samedir);
else if (!old_opaque && ovl_type_merge(new->d_parent))
- err = ovl_set_opaque(old, olddentry);
+ err = ovl_set_opaque_xerr(old, olddentry, -EXDEV);
if (err)
goto out_dput;
}
@@ -1000,7 +1009,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
if (ovl_type_merge_or_lower(new))
err = ovl_set_redirect(new, samedir);
else if (!new_opaque && ovl_type_merge(old->d_parent))
- err = ovl_set_opaque(new, newdentry);
+ err = ovl_set_opaque_xerr(new, newdentry, -EXDEV);
if (err)
goto out_dput;
}
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index ce7c3aba61e46f..505b18b5633033 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -206,7 +206,6 @@ bool ovl_dentry_is_opaque(struct dentry *dentry);
bool ovl_dentry_is_whiteout(struct dentry *dentry);
void ovl_dentry_set_opaque(struct dentry *dentry);
bool ovl_redirect_dir(struct super_block *sb);
-void ovl_clear_redirect_dir(struct super_block *sb);
const char *ovl_dentry_get_redirect(struct dentry *dentry);
void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect);
void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index b5a0dc36ee968c..4d541a8d083451 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -191,14 +191,7 @@ bool ovl_redirect_dir(struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
- return ofs->config.redirect_dir;
-}
-
-void ovl_clear_redirect_dir(struct super_block *sb)
-{
- struct ovl_fs *ofs = sb->s_fs_info;
-
- ofs->config.redirect_dir = false;
+ return ofs->config.redirect_dir && !ofs->noxattr;
}
const char *ovl_dentry_get_redirect(struct dentry *dentry)
--
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