kernel_optimize_test/fs/overlayfs
Amir Goldstein dfe51d47b7 ovl: avoid possible inode number collisions with xino=on
When xino feature is enabled and a real directory inode number overflows
the lower xino bits, we cannot map this directory inode number to a unique
and persistent inode number and we fall back to the real inode st_ino and
overlay st_dev.

The real inode st_ino with high bits may collide with a lower inode number
on overlay st_dev that was mapped using xino.

To avoid possible collision with legitimate xino values, map a non
persistent inode number to a dedicated range in the xino address space.
The dedicated range is created by adding one more bit to the number of
reserved high xino bits.  We could have added just one more fsid, but that
would have had the undesired effect of changing persistent overlay inode
numbers on kernel or require more complex xino mapping code.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-03-27 16:51:02 +01:00
..
copy_up.c ovl: ignore failure to copy up unknown xattrs 2020-03-17 15:04:22 +01:00
dir.c ovl: fix WARN_ON nlink drop to zero 2020-03-27 16:51:02 +01:00
export.c ovl: ovl_obtain_alias(): don't call d_instantiate_anon() for old 2020-03-17 15:04:23 +01:00
file.c ovl: fix lockdep warning for async write 2020-03-13 15:53:06 +01:00
inode.c ovl: avoid possible inode number collisions with xino=on 2020-03-27 16:51:02 +01:00
Kconfig ovl: fix some xino configurations 2020-03-13 15:53:06 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
namei.c ovl: allow remote upper 2020-03-17 15:04:22 +01:00
overlayfs.h ovl: replace zero-length array with flexible-array member 2020-03-17 15:04:23 +01:00
ovl_entry.h ovl: use a private non-persistent ino pool 2020-03-27 16:51:02 +01:00
readdir.c ovl: avoid possible inode number collisions with xino=on 2020-03-27 16:51:02 +01:00
super.c ovl: avoid possible inode number collisions with xino=on 2020-03-27 16:51:02 +01:00
util.c ovl: allow remote upper 2020-03-17 15:04:22 +01:00