Hi Okajima,
Looking at aufs3.x sources, I see the same behavior ie., that if code ever
hits below condition it evaluates to true (if CRAMFS is not configured). I
can try enabling CONFIG_AUFS_HNOTIFY option but is there is anyway I could
verify that enabling this config and using mount option "fixes" this issue.
if (unlikely(au_test_fs_unique_ino(h_dentry->d_inode)))
AuWarn1("Warning: Un-notified UDBA or repeatedly renamed
dir,"
" b%d, %s, %.*s, hi%lu, i%lu.\n",
bstart, au_sbtype(h_dentry->d_sb),
AuDLNPair(dentry),
(unsigned long)h_ino, (unsigned long)ino);
thank you.
p.s: i hope these mails are not garbled.
On Wed, Feb 6, 2013 at 11:44 AM, Prasad Koya <[1]prasad.k...@gmail.com>
wrote:
Hi Okajima,
While we are moving to 3.4 kernel we are trying to support our 2.6.x
version of kernel which has aufs 2.2.
Reviving the old thread dated Oct 17, 2012, I see that
if (unlikely(au_test_fs_unique_ino(h_dentry->d_inode)))
AuWarn1("Warning: Un-notified UDBA or repeatedly renamed
dir,"
" b%d, %s, %.*s, hi%lu, i%lu.\n",
bstart, au_sbtype(h_dentry->d_sb),
AuDLNPair(dentry),
(unsigned long)h_ino, (unsigned long)ino);
if CONFIG_CRAMFS_MODULE or CONFIG_CRAMFS are not defined,
au_test_fs_unique_ino() will always return true and it will print
above warning. As you suggested that implementation of aufs in 2.2 is
poor, is it safe to turn off that comment?
I tried to reproduce the issue again y'day but without any luck:
mount --bind /var/log /tmp/storage
mount -o remount,ro,bind /var/log /tmp/storage
mount -t aufs -o dirs=/var/core:/tmp/storage none /tmp/x1
effectively this is what I believe I'm doing:
1 - /u = /rw + /ro
2 - run "> /u/file" once
3 - repeat "stat /u/file > /dev/null" in background
4 - repeat "> /rw/file2; mv /rw/file2 /rw/file"
I ran 3 and 4 in infinite loop, parallelly in two different terminals.
I'm ok with enabling CONFIG_AUFS_HNOTIFY and use "udba=notify" but it
would be great if I can validate that this option is helping. The
option in Kconfig clearly says this will have performance hit.
config AUFS_HNOTIFY
bool "Detect direct branch access (bypassing aufs)"
help
If you want to modify files on branches directly, eg. bypassing
aufs,
and want aufs to detect the changes of them fully, then enable
this
option and use 'udba=notify' mount option.
Currently there is only one available configuration, "fsnotify".
It will have a negative impact to the performance.
See detail in aufs.5.
Pl advise.
thanks for your time
Prasad
References
1. mailto:prasad.k...@gmail.com
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