Change the getxattr inode operation to only use its inode argument, and
ignore the dentry. This is possible because on overlayfs, each dentry
has a separate inode and inodes are not shared among dentries. Allows
SELinux to work on top of overlayfs.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
fs/overlayfs/inode.c | 26 +++++++++++++++-----------
fs/overlayfs/overlayfs.h | 1 +
fs/overlayfs/super.c | 10 +++++++---
3 files changed, 23 insertions(+), 14 deletions(-)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 8c3f985..7acc145 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -238,29 +238,32 @@ out:
return err;
}
-static bool ovl_need_xattr_filter(struct dentry *dentry,
+static bool ovl_need_xattr_filter(struct inode *inode,
enum ovl_path_type type)
{
if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
- return S_ISDIR(dentry->d_inode->i_mode);
+ return S_ISDIR(inode->i_mode);
else
return false;
}
-ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
+ssize_t ovl_getxattr(struct dentry *unused, struct inode *inode,
const char *name, void *value, size_t size)
{
- struct path realpath;
+ struct ovl_entry *oe = inode->i_private;
enum ovl_path_type type;
+ struct dentry *realdentry;
+ bool is_upper;
- if (!dentry)
- return -ECHILD;
+ realdentry = ovl_entry_real(oe, &is_upper);
+ if (!realdentry->d_inode)
+ return -ENOENT;
- type = ovl_path_real(dentry, &realpath);
- if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
+ type = __ovl_path_type(oe, inode->i_mode);
+ if (ovl_need_xattr_filter(inode, type) && ovl_is_private_xattr(name))
return -ENODATA;
- return vfs_getxattr(realpath.dentry, name, value, size);
+ return vfs_getxattr(realdentry, name, value, size);
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
@@ -274,7 +277,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
if (res <= 0 || size == 0)
return res;
- if (!ovl_need_xattr_filter(dentry, type))
+ if (!ovl_need_xattr_filter(dentry->d_inode, type))
return res;
/* filter out private xattrs */
@@ -306,7 +309,8 @@ int ovl_removexattr(struct dentry *dentry, const char *name)
goto out;
err = -ENODATA;
- if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
+ if (ovl_need_xattr_filter(dentry->d_inode, type) &&
+ ovl_is_private_xattr(name))
goto out_drop_write;
if (!OVL_TYPE_UPPER(type)) {
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 4bd9b5b..0d1430f 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -131,6 +131,7 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
return err;
}
+enum ovl_path_type __ovl_path_type(struct ovl_entry *oe, umode_t mode);
enum ovl_path_type ovl_path_type(struct dentry *dentry);
u64 ovl_dentry_version_get(struct dentry *dentry);
void ovl_dentry_version_inc(struct dentry *dentry);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index ce02f46..d04546e 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -70,9 +70,8 @@ static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe)
return oe->numlower ? oe->lowerstack[0].dentry : NULL;
}
-enum ovl_path_type ovl_path_type(struct dentry *dentry)
+enum ovl_path_type __ovl_path_type(struct ovl_entry *oe, umode_t mode)
{
- struct ovl_entry *oe = dentry->d_fsdata;
enum ovl_path_type type = 0;
if (oe->__upperdentry) {
@@ -82,7 +81,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
* Non-dir dentry can hold lower dentry from previous
* location. Its purity depends only on opaque flag.
*/
- if (oe->numlower && S_ISDIR(dentry->d_inode->i_mode))
+ if (oe->numlower && S_ISDIR(mode))
type |= __OVL_PATH_MERGE;
else if (!oe->opaque)
type |= __OVL_PATH_PURE;
@@ -93,6 +92,11 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry)
return type;
}
+enum ovl_path_type ovl_path_type(struct dentry *dentry)
+{
+ return __ovl_path_type(dentry->d_fsdata, dentry->d_inode->i_mode);
+}
+
static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
{
return lockless_dereference(oe->__upperdentry);
--
2.5.5
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
