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>

diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index 56b8d3a..a6162c4 100644 (file)
--- 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 feef0ea..7bce246 100644 (file)
--- 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 17bfc19..23f4756 100644 (file)
--- 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;
        }