在 2024/7/3 23:18, Amir Goldstein 写道:
On Wed, Jul 3, 2024 at 4:48 PM Christian Brauner <brauner@xxxxxxxxxx> wrote:
[...]
This fix looks correct, but it is not pretty IMO.
The cleanup on error is much cleaner in ovl_parse_layer() -> ovl_add_layer()
I wonder if we can reuse some of those helpers instead of the current code.
Christian, what do you think?
Yeah, sounds good. Something like the completely untested below.
Feel free to reuse in whatever form.
Thanks Christian, it's so nice of you.
This looks much nicer!
I think you unintentionally dropped incrementing of ctx->nr_data
for the notorious case of ::<lowerdatadir>.
Hi, Amir, thanks for reminding, I modify some points based on the
patches from Christian:
1. Use ovl_mount_dir() to parse parameter string for Opt_lowerdir,
because I found the character '\' can be filtered from parameter string
for Opt_lowerdir, so I want to keep it(Not sure whether it's right).
mount("none", "/root/tmp/merge", "overlay", 0, "lowerdir=low\\er:lower2")
2. Keep 'ctx->nr_data' updating in ovl_parse_param_lowerdir(). I was
going to move 'ctx->nr_data' updating into ovl_add_layer() by passing
'Opt_datadir_add' into ovl_parse_layer(), but I found
ovl_mount_dir_check() use this opt to do some check, the opt should be
Opt_lowerdir.
3. Remove 'out_put' error handling branch from
ovl_parse_param_lowerdir(), because ovl_fs_context_free is invoked if
something error happens.
Zhihao,
Please make sure to run the fstests overlay test for lowerdatadirs
overlay/079 overlay/085 overlay/086
BTW, I get overlay/061 failed even before applying my patches. Maybe I
will take some time to analyze it.
overlay/061 - output mismatch (see
/root/git/xfstests-dev/results//overlay/061.out.bad)
--- tests/overlay/061.out 2023-04-01 14:14:58.354052795 +0800
+++ /root/git/xfstests-dev/results//overlay/061.out.bad 2024-07-04
14:52:44.993000000 +0800
@@ -1,4 +1,4 @@
QA output created by 061
-00000000: 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61
aaaaaaaaaaaaaaaa
+00000000: 54 68 69 73 20 69 73 20 6f 6c 64 20 6e 65 77 73
This.is.old.news
After mount cycle:
00000000: 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61
aaaaaaaaaaaaaaaa
...
(Run 'diff -u /root/git/xfstests-dev/tests/overlay/061.out
/root/git/xfstests-dev/results//overlay/061.out.bad' to see the entire
diff)
v2 pacthes:
https://lore.kernel.org/linux-unionfs/20240704070323.3365042-1-chengzhihao1@xxxxxxxxxx/T/#mdaedba39d7f261cd2555ea6773ed3611c02e7a4e
