forked from Minki/linux
096a218a58
When a lower file has immutable/append-only fileattr flags, the behavior of overlayfs post copy up is inconsistent. Immediattely after copy up, ovl inode still has the S_IMMUTABLE/S_APPEND inode flags copied from lower inode, so vfs code still treats the ovl inode as immutable/append-only. After ovl inode evict or mount cycle, the ovl inode does not have these inode flags anymore. We cannot copy up the immutable and append-only fileattr flags, because immutable/append-only inodes cannot be linked and because overlayfs will not be able to set overlay.* xattr on the upper inodes. Instead, if any of the fileattr flags of interest exist on the lower inode, we store them in overlay.protattr xattr on the upper inode and we read the flags from xattr on lookup and on fileattr_get(). This gives consistent behavior post copy up regardless of inode eviction from cache. When user sets new fileattr flags, we update or remove the overlay.protattr xattr. Storing immutable/append-only fileattr flags in an xattr instead of upper fileattr also solves other non-standard behavior issues - overlayfs can now copy up children of "ovl-immutable" directories and lower aliases of "ovl-immutable" hardlinks. Reported-by: Chengguang Xu <cgxu519@mykernel.net> Link: https://lore.kernel.org/linux-unionfs/20201226104618.239739-1-cgxu519@mykernel.net/ Link: https://lore.kernel.org/linux-unionfs/20210210190334.1212210-5-amir73il@gmail.com/ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> |
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| .. | ||
| copy_up.c | ||
| dir.c | ||
| export.c | ||
| file.c | ||
| inode.c | ||
| Kconfig | ||
| Makefile | ||
| namei.c | ||
| overlayfs.h | ||
| ovl_entry.h | ||
| readdir.c | ||
| super.c | ||
| util.c | ||