diff options
Diffstat (limited to 'fs/overlayfs/util.c')
| -rw-r--r-- | fs/overlayfs/util.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index f8455fcb8b07..73ac47b49218 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -601,6 +601,16 @@ bool ovl_is_whiteout(struct dentry *dentry) return inode && IS_WHITEOUT(inode); } +/* + * Use this over ovl_is_whiteout for upper and lower files, as it also + * handles overlay.whiteout xattr whiteout files. + */ +bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path) +{ + return ovl_is_whiteout(path->dentry) || + ovl_path_check_xwhiteout_xattr(ofs, path); +} + struct file *ovl_path_open(const struct path *path, int flags) { struct inode *inode = d_inode(path->dentry); @@ -716,6 +726,32 @@ bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path) return false; } +bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path) +{ + struct dentry *dentry = path->dentry; + int res; + + /* xattr.whiteout must be a zero size regular file */ + if (!d_is_reg(dentry) || i_size_read(d_inode(dentry)) != 0) + return false; + + res = ovl_path_getxattr(ofs, path, OVL_XATTR_XWHITEOUT, NULL, 0); + return res >= 0; +} + +bool ovl_path_check_xwhiteouts_xattr(struct ovl_fs *ofs, const struct path *path) +{ + struct dentry *dentry = path->dentry; + int res; + + /* xattr.whiteouts must be a directory */ + if (!d_is_dir(dentry)) + return false; + + res = ovl_path_getxattr(ofs, path, OVL_XATTR_XWHITEOUTS, NULL, 0); + return res >= 0; +} + /* * Load persistent uuid from xattr into s_uuid if found, or store a new * random generated value in s_uuid and in xattr. @@ -800,6 +836,8 @@ bool ovl_path_check_dir_xattr(struct ovl_fs *ofs, const struct path *path, #define OVL_XATTR_UUID_POSTFIX "uuid" #define OVL_XATTR_METACOPY_POSTFIX "metacopy" #define OVL_XATTR_PROTATTR_POSTFIX "protattr" +#define OVL_XATTR_XWHITEOUT_POSTFIX "whiteout" +#define OVL_XATTR_XWHITEOUTS_POSTFIX "whiteouts" #define OVL_XATTR_TAB_ENTRY(x) \ [x] = { [false] = OVL_XATTR_TRUSTED_PREFIX x ## _POSTFIX, \ @@ -815,6 +853,8 @@ const char *const ovl_xattr_table[][2] = { OVL_XATTR_TAB_ENTRY(OVL_XATTR_UUID), OVL_XATTR_TAB_ENTRY(OVL_XATTR_METACOPY), OVL_XATTR_TAB_ENTRY(OVL_XATTR_PROTATTR), + OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUT), + OVL_XATTR_TAB_ENTRY(OVL_XATTR_XWHITEOUTS), }; int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, |