On 2/2/24 10:51, Amir Goldstein wrote:
On Fri, Feb 2, 2024 at 4:59 PM Stefan Berger <stefanb@xxxxxxxxxxxxx> wrote:
On 2/2/24 04:24, Amir Goldstein wrote:
On Thu, Feb 1, 2024 at 10:35 PM Stefan Berger <stefanb@xxxxxxxxxxxxx> wrote:
and your suggested change to this patch :
- struct inode *inode = d_real_inode(dentry);
+ struct inode *inode = d_inode(d_real(dentry, false));;
In the new version I change the API to use an enum instead of bool, e.g.:
struct inode *inode = d_inode(d_real(dentry, D_REAL_METADATA));
Thanks. I will use it.
This catches in build time and in run time, callers that were not converted
to the new API.
The test cases are now passing with and without metacopy enabled. Yay!
Too soon to be happy.
I guess you are missing a test for the following case:
1. file was meta copied up (change is detected)
2. the lower file that contains the data is being changed (change is
not detected)
Right. Though it seems there's something wrong with overlayfs as well
after appending a byte to the file on the lower.
-rwxr-xr-x 1 0 0 25 Feb 2 14:55
/ext4.mount/lower/test_rsa_portable2
-rwxr-xr-x 1 0 0 24 Feb 2 14:55
/ext4.mount/overlay/test_rsa_portable2
bb16aa5350bcc8863da1a873c846fec9281842d9
/ext4.mount/lower/test_rsa_portable2
bb16aa5350bcc8863da1a873c846fec9281842d9
/ext4.mount/overlay/test_rsa_portable2
We have a hash collision on a file with 24 bytes and the underlying one
with 25 byte. (-; :-)
https://docs.kernel.org/filesystems/overlayfs.html#changes-to-underlying-filesystems
If you modify the lower file underneath overlayfs, you get no
guarantee from overlayfs about expected results.
This makes your work more challenging.
The odd thing is my updated test case '2' seems to indicate that
everything already works as expected with CONFIG_OVERLAY_FS_METACOPY=y.
After causing copy-up of metadata changes to the file content on the
lower layer still cause permission error to file execution on the
overlay layer and after restoring the file content on the lower the file
on the overlay again runs as expected. The file content change + copy-up
of file content also has completely decoupled the lower file from the
file on the overlay and changes to the file on the lower cause no more
file execution rejections on the overlay.
Stefan
Thanks,
Amir.
