Define D_REAL_FILEDATA which is to be used as a parameter for d_real() to return the dentry that is holding the file data, which is either the upper or the lower denry. The caller is expected to call d_real() again on the returned dentry to get to lower layers of a stacked filesystem, if available.
Signed-off-by: Stefan Berger <[email protected]> --- fs/overlayfs/super.c | 6 ++++++ include/linux/dcache.h | 1 + 2 files changed, 7 insertions(+) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 06a231970cb5..f466ad89b005 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -36,6 +36,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, enum d_real_type type) switch (type) { case D_REAL_DATA: case D_REAL_METADATA: + case D_REAL_FILEDATA: break; default: goto bug; @@ -47,6 +48,11 @@ static struct dentry *ovl_d_real(struct dentry *dentry, enum d_real_type type) } upper = ovl_dentry_upper(dentry); + if (type == D_REAL_FILEDATA) { + if (ovl_has_upperdata(d_inode(dentry))) + return upper; + return ovl_dentry_lower(dentry); + } if (upper && (type == D_REAL_METADATA || ovl_has_upperdata(d_inode(dentry)))) return upper; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index bf53e3894aae..e4e54fb2cf4e 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -128,6 +128,7 @@ enum dentry_d_lock_class enum d_real_type { D_REAL_DATA, D_REAL_METADATA, + D_REAL_FILEDATA, }; struct dentry_operations { -- 2.43.0
