From 43d193f8440d67f0dddd93ae973eb94174039e83 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Wed, 2 Sep 2020 10:58:49 +0200
Subject: [PATCH] ovl: enumerate private xattrs
Instead of passing the xattr name down to the ovl_do_*xattr() accessor
functions, pass an enumerated value. The enum can use the same names as
the the previous #define for each xattr name.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/overlayfs/namei.c | 16 ++++++++--------
fs/overlayfs/overlayfs.h | 38 +++++++++++++++++++++++++-------------
fs/overlayfs/util.c | 31 ++++++++++++++++++++++++++-----
3 files changed, 59 insertions(+), 26 deletions(-)
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 56b8d3afa1f27e..a6162c4076db73 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -106,12 +106,12 @@ int ovl_check_fb_len(struct ovl_fb *fb, int fb_len)
}
static struct ovl_fh *ovl_get_fh(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name)
+ enum ovl_xattr ox)
{
int res, err;
struct ovl_fh *fh = NULL;
- res = ovl_do_getxattr(ofs, dentry, name, NULL, 0);
+ res = ovl_do_getxattr(ofs, dentry, ox, NULL, 0);
if (res < 0) {
if (res == -ENODATA || res == -EOPNOTSUPP)
return NULL;
@@ -125,7 +125,7 @@ static struct ovl_fh *ovl_get_fh(struct ovl_fs *ofs, struct dentry *dentry,
if (!fh)
return ERR_PTR(-ENOMEM);
- res = ovl_do_getxattr(ofs, dentry, name, fh->buf, res);
+ res = ovl_do_getxattr(ofs, dentry, ox, fh->buf, res);
if (res < 0)
goto fail;
@@ -416,9 +416,9 @@ static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
* Return 0 on match, -ESTALE on mismatch, < 0 on error.
*/
static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name, const struct ovl_fh *fh)
+ enum ovl_xattr ox, const struct ovl_fh *fh)
{
- struct ovl_fh *ofh = ovl_get_fh(ofs, dentry, name);
+ struct ovl_fh *ofh = ovl_get_fh(ofs, dentry, ox);
int err = 0;
if (!ofh)
@@ -443,7 +443,7 @@ static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry,
* Return 0 on match, -ESTALE on mismatch, -ENODATA on no xattr, < 0 on error.
*/
int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name, struct dentry *real, bool is_upper,
+ enum ovl_xattr ox, struct dentry *real, bool is_upper,
bool set)
{
struct inode *inode;
@@ -457,9 +457,9 @@ int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
goto fail;
}
- err = ovl_verify_fh(ofs, dentry, name, fh);
+ err = ovl_verify_fh(ofs, dentry, ox, fh);
if (set && err == -ENODATA)
- err = ovl_do_setxattr(ofs, dentry, name, fh->buf, fh->fb.len);
+ err = ovl_do_setxattr(ofs, dentry, ox, fh->buf, fh->fb.len);
if (err)
goto fail;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index feef0eadc5b39b..7bce2469fe559f 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -23,13 +23,16 @@ enum ovl_path_type {
#define OVL_TYPE_ORIGIN(type) ((type) & __OVL_PATH_ORIGIN)
#define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay."
-#define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque"
-#define OVL_XATTR_REDIRECT OVL_XATTR_PREFIX "redirect"
-#define OVL_XATTR_ORIGIN OVL_XATTR_PREFIX "origin"
-#define OVL_XATTR_IMPURE OVL_XATTR_PREFIX "impure"
-#define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink"
-#define OVL_XATTR_UPPER OVL_XATTR_PREFIX "upper"
-#define OVL_XATTR_METACOPY OVL_XATTR_PREFIX "metacopy"
+
+enum ovl_xattr {
+ OVL_XATTR_OPAQUE,
+ OVL_XATTR_REDIRECT,
+ OVL_XATTR_ORIGIN,
+ OVL_XATTR_IMPURE,
+ OVL_XATTR_NLINK,
+ OVL_XATTR_UPPER,
+ OVL_XATTR_METACOPY,
+};
enum ovl_inode_flag {
/* Pure upper dir that may contain non pure upper entries */
@@ -110,6 +113,12 @@ struct ovl_fh {
#define OVL_FH_FID_OFFSET (OVL_FH_WIRE_OFFSET + \
offsetof(struct ovl_fb, fid))
+extern const char *ovl_xattr_table[];
+static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox)
+{
+ return ovl_xattr_table[ox];
+}
+
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
{
int err = vfs_rmdir(dir, dentry);
@@ -171,16 +180,18 @@ static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
}
static inline ssize_t ovl_do_getxattr(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name, void *value,
+ enum ovl_xattr ox, void *value,
size_t size)
{
+ const char *name = ovl_xattr(ofs, ox);
return vfs_getxattr(dentry, name, value, size);
}
static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name, const void *value,
+ enum ovl_xattr ox, const void *value,
size_t size)
{
+ const char *name = ovl_xattr(ofs, ox);
int err = vfs_setxattr(dentry, name, value, size, 0);
pr_debug("setxattr(%pd2, \"%s\", \"%*pE\", %zu, 0) = %i\n",
dentry, name, min((int)size, 48), value, size, err);
@@ -188,8 +199,9 @@ static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry,
}
static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name)
+ enum ovl_xattr ox)
{
+ const char *name = ovl_xattr(ofs, ox);
int err = vfs_removexattr(dentry, name);
pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
return err;
@@ -291,9 +303,9 @@ void ovl_copy_up_end(struct dentry *dentry);
bool ovl_already_copied_up(struct dentry *dentry, int flags);
bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry);
bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
- const char *name);
+ enum ovl_xattr ox);
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
- const char *name, const void *value, size_t size,
+ enum ovl_xattr ox, const void *value, size_t size,
int xerr);
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
void ovl_set_flag(unsigned long flag, struct inode *inode);
@@ -376,7 +388,7 @@ struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
struct dentry *upperdentry, struct ovl_path **stackp);
int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
- const char *name, struct dentry *real, bool is_upper,
+ enum ovl_xattr ox, struct dentry *real, bool is_upper,
bool set);
struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index);
int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 17bfc19625d0e1..23f475627d07f8 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -558,7 +558,7 @@ bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry)
}
bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
- const char *name)
+ enum ovl_xattr ox)
{
int res;
char val;
@@ -566,15 +566,36 @@ bool ovl_check_dir_xattr(struct super_block *sb, struct dentry *dentry,
if (!d_is_dir(dentry))
return false;
- res = ovl_do_getxattr(OVL_FS(sb), dentry, name, &val, 1);
+ res = ovl_do_getxattr(OVL_FS(sb), dentry, ox, &val, 1);
if (res == 1 && val == 'y')
return true;
return false;
}
+#define OVL_XATTR_OPAQUE_POSTFIX "opaque"
+#define OVL_XATTR_REDIRECT_POSTFIX "redirect"
+#define OVL_XATTR_ORIGIN_POSTFIX "origin"
+#define OVL_XATTR_IMPURE_POSTFIX "impure"
+#define OVL_XATTR_NLINK_POSTFIX "nlink"
+#define OVL_XATTR_UPPER_POSTFIX "upper"
+#define OVL_XATTR_METACOPY_POSTFIX "metacopy"
+
+#define OVL_XATTR_TAB_ENTRY(x) \
+ [x] = OVL_XATTR_PREFIX x ## _POSTFIX
+
+const char *ovl_xattr_table[] = {
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_OPAQUE),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_REDIRECT),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_ORIGIN),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_IMPURE),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_NLINK),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_UPPER),
+ OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY),
+};
+
int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
- const char *name, const void *value, size_t size,
+ enum ovl_xattr ox, const void *value, size_t size,
int xerr)
{
int err;
@@ -583,10 +604,10 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
if (ofs->noxattr)
return xerr;
- err = ovl_do_setxattr(ofs, upperdentry, name, value, size);
+ err = ovl_do_setxattr(ofs, upperdentry, ox, value, size);
if (err == -EOPNOTSUPP) {
- pr_warn("cannot set %s xattr on upper\n", name);
+ pr_warn("cannot set %s xattr on upper\n", ovl_xattr(ofs, ox));
ofs->noxattr = true;
return xerr;
}
--
GitLab