Hi,
# drop torvalds@xxxxxxxxxxxxxxxxxxxx, linux-mm@xxxxxxxxx, linux-fsdevel@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
A Question about ETXTBSY of nfs.
# I tried google/bing, but yet no good info is found.
test case:
/ssd is a nfs directory
kernel: 5.10.61, 5.4.106 and more
1, on Node1:
[root@T630 ~]# echo -e '#!/bin/bash\necho hello' >/ssd/a.sh
[root@T630 ~]# chmod a+x /ssd/a.sh
2, on Node2:
[root@T640 ~]# /ssd/a.sh
-bash: /ssd/a.sh: /bin/bash: bad interpreter: Text file busy
[root@T640 ~]# bash /ssd/a.sh
hello
[root@T640 ~]# /ssd/a.sh
-bash: /ssd/a.sh: /bin/bash: bad interpreter: Text file busy
Is there any way(flush, sync) to avoid this ETXTBSY error(Text file busy)?
Best Regards
Wang Yugui (wangyugui@xxxxxxxxxxxx)
2021/09/02
> On Thu, Aug 26, 2021 at 09:57:39AM +1000, NeilBrown wrote:
> >
> > Commit dc617f29dbe5 ("vfs: don't allow writes to swap files")
> > broke swap-over-NFS as it introduced an ETXTBSY error when NFS tries to
> > swap-out using ->direct_IO().
> >
> > There is no sound justification for this error. File permissions are
> > sufficient to stop non-root users from writing to a swap file, and root
> > must always be cautious not to do anything dangerous.
> >
> > These checks effectively provide a mandatory write lock on swap, and
> > mandatory locks are not supported in Linux.
> >
> > So remove all the checks that return ETXTBSY when attempts are made to
> > write to swap.
>
> Swap files are not just any files and do need a mandatory write lock
> as they are part of the kernel VM and writing to them will mess up
> the kernel badly. David Howells actually has sent various patches
> to fix swap over NFS in the last weeks.
