Delete a directory, crash the system
I had a strange experience on my laptop yesterday. I was deleting a directory and the system crashed. It spat out a message along the lines of ufs_dirrem bad link count 2 on parent. I thought it was so strange I repeated the process several times, and each time it crashed. Is this behavior EXPECTED? I can't for the life of me think of a time or operating system I've run where I've ever had a system crash on me from doing something as basic as deleting a file. Anyway I couldn't boot into single user for some reason so I booted from a USB image, ran fsck, and then everything was fine. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
El 27/07/2013 13:49, David Noel david.i.n...@gmail.com escribió: I had a strange experience on my laptop yesterday. I was deleting a directory and the system crashed. It spat out a message along the lines of ufs_dirrem bad link count 2 on parent. I thought it was so strange I repeated the process several times, and each time it crashed. Is this behavior EXPECTED? I can't for the life of me think of a time or operating system I've run where I've ever had a system crash on me from doing something as basic as deleting a file. Anyway I couldn't boot into single user for some reason so I booted from a USB image, ran fsck, and then everything was fine. Was it a kernel crash? Did you get a core? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
Yes On 7/27/13, Fernando Apesteguía fernando.apesteg...@gmail.com wrote: El 27/07/2013 13:49, David Noel david.i.n...@gmail.com escribió: I had a strange experience on my laptop yesterday. I was deleting a directory and the system crashed. It spat out a message along the lines of ufs_dirrem bad link count 2 on parent. I thought it was so strange I repeated the process several times, and each time it crashed. Is this behavior EXPECTED? I can't for the life of me think of a time or operating system I've run where I've ever had a system crash on me from doing something as basic as deleting a file. Anyway I couldn't boot into single user for some reason so I booted from a USB image, ran fsck, and then everything was fine. Was it a kernel crash? Did you get a core? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
El 27/07/2013 14:16, David Noel david.i.n...@gmail.com escribió: Yes Post the stack trace of the core and maybe someone can help you. On 7/27/13, Fernando Apesteguía fernando.apesteg...@gmail.com wrote: El 27/07/2013 13:49, David Noel david.i.n...@gmail.com escribió: I had a strange experience on my laptop yesterday. I was deleting a directory and the system crashed. It spat out a message along the lines of ufs_dirrem bad link count 2 on parent. I thought it was so strange I repeated the process several times, and each time it crashed. Is this behavior EXPECTED? I can't for the life of me think of a time or operating system I've run where I've ever had a system crash on me from doing something as basic as deleting a file. Anyway I couldn't boot into single user for some reason so I booted from a USB image, ran fsck, and then everything was fine. Was it a kernel crash? Did you get a core? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
Post the stack trace of the core and maybe someone can help you. panic: ufs_dirrem: Bad link count 2 on parent cpuid = 0 KDB: stack backtrace: #0 0x808680fe at kdb_backtrace+0x5e #1 0x80832cb7 at panic+0x187 #2 0x80a700e3 at ufs_rmdir+0x1c3 #3 0x80b7d484 at VOP_RMDIR_APV+0x34 #4 0x808ca32a at kern_rmdirat+0x21a #5 0x80b17cf0 at amd64_syscall+0x450 #6 0x80b03427 at Xfast_syscall+0xf7 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
On 27/07/2013 13:58, David Noel wrote: Post the stack trace of the core and maybe someone can help you. panic: ufs_dirrem: Bad link count 2 on parent cpuid = 0 KDB: stack backtrace: #0 0x808680fe at kdb_backtrace+0x5e #1 0x80832cb7 at panic+0x187 #2 0x80a700e3 at ufs_rmdir+0x1c3 #3 0x80b7d484 at VOP_RMDIR_APV+0x34 #4 0x808ca32a at kern_rmdirat+0x21a #5 0x80b17cf0 at amd64_syscall+0x450 #6 0x80b03427 at Xfast_syscall+0xf7 I'm taking a guess here - the effective link count when it came to removing the parent directory was only two and it should have been three or more. This gets sanity checked this before proceeding, and panics if it is not. Why an effective link count of three? We're talking about the parent of the directory you're trying to zap, right? There's the link to the directory from its parent, and the '.' link and the .. link from the directory you're trying to remove. There may be more if it contains other directories, but there can't be less. Anyway - if you only had a link count of just two effective links at the start of the delete process it suggests that the link count was messed up - either a link never existed or its count was wrong. Should the kernel panic? Well it's a situation that can never happen - it could simply remove the directory and pretend everything was okay but guess it was decided it was likely to be a symptom of impending disaster. Other anomalies return an error. In over ten years with FreeBSD systems I can't say I've ever seen this cannot happen situation arise. I'd guess you had an interrupted (by power failure) inode operation at some time which caused the corruption. removing a directory is a PITA as it can lead to a race - a context swap could create a file it it mid-way through the process. Regards, Frank. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
I'm taking a guess here - the effective link count when it came to removing the parent directory was only two and it should have been three or more. This gets sanity checked this before proceeding, and panics if it is not. Why an effective link count of three? We're talking about the parent of the directory you're trying to zap, right? There's the link to the directory from its parent, and the '.' link and the .. link from the directory you're trying to remove. There may be more if it contains other directories, but there can't be less. Anyway - if you only had a link count of just two effective links at the start of the delete process it suggests that the link count was messed up - either a link never existed or its count was wrong. Should the kernel panic? Well it's a situation that can never happen - it could simply remove the directory and pretend everything was okay but guess it was decided it was likely to be a symptom of impending disaster. Other anomalies return an error. In over ten years with FreeBSD systems I can't say I've ever seen this cannot happen situation arise. I'd guess you had an interrupted (by power failure) inode operation at some time which caused the corruption. removing a directory is a PITA as it can lead to a race - a context swap could create a file it it mid-way through the process. Regards, Frank. Interesting. Thanks for the analysis. I'm not a systems guy (Java, mostly), so I don't really have the context to make much sense of kgdb output. What you're saying though makes sense and sounds about right -- it's a laptop and I've inadvertently run the battery down to nothing a few times in the past. All the same, it was a very strange experience. I would not have expected a kernel panic from a simple rm -rf! ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: /usr/src for 9.2 beta?
On Fri, 26 Jul 2013 17:56:09 -0400, kpneal wrote: On Fri, Jul 26, 2013 at 07:30:17PM +, Walter Hurry wrote: I'd like to try out 9.2-BETA1 on a test box. From where do I check out the sources please (using svn)? I believe you want: svn co svn://svn.freebsd.org/base/stable/9 After 9.2 is released you'll be able to use: svn co svn://svn.freebsd.org/base/releng/9.2 But if I'm not mistaken until then you'll want stable/9. Thanks. Yes, that seems to work. By the way, I did search svn.freebsd.org/base prior to posting, but didn't see anything obvious. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
On 07/27/2013 11:30, David Noel wrote: -- it's a laptop and I've inadvertently run the battery down to nothing a few times in the past. All the same, it was a very strange experience. I would not have expected a kernel panic from a simple rm -rf! You may want to look into running fsck(8) and its myriad of options to try to clean up the problem (assuming you're using a ufs filesystem also see fsck_ufs(8)). fsck normally runs during startup but perhaps a set of non-default options will do the trick. Also make sure you have soft updates enabled on your filesystem and preferably journaled soft updates, if for some odd reason you don't, as that is designed to avoid filesystem inconsistencies in the face of things like power failures. Sincerely, Jason ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
On 07/27/13 14:58, David Noel wrote: Post the stack trace of the core and maybe someone can help you. panic: ufs_dirrem: Bad link count 2 on parent cpuid = 0 KDB: stack backtrace: #0 0x808680fe at kdb_backtrace+0x5e #1 0x80832cb7 at panic+0x187 #2 0x80a700e3 at ufs_rmdir+0x1c3 #3 0x80b7d484 at VOP_RMDIR_APV+0x34 #4 0x808ca32a at kern_rmdirat+0x21a #5 0x80b17cf0 at amd64_syscall+0x450 #6 0x80b03427 at Xfast_syscall+0xf7 So the system panics in ufs_rmdir(). Maybe the filesystem is corrupt? Have you tried to fsck(8) it manually? Even if the filesystem is corrupt, ufs_rmdir() shouldn't panic(), IMHO, but fail gracefully. Hmmm... -cpghost. -- Cordula's Web. http://www.cordula.ws/ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
FreeBSD slices and the Boot Manager
Hi, I have a workstation with two factory installed hard disks. The first disk, ada0, is occupied by a Windows 7 Pro OS (mainly kept for the three year warranty of the workstation as Dell techs mostly speak the Microsoft language). Instead I have configured the BIOS to boot from the MBR on the second disk as I most of the time (99%) use FreeBSD. The MBR on ada1 was installed with sysinstall's option Install the FreeBSD Boot Manager, when I installed the FreeBSD 8.3-RELEASE. (The latest BIOS version 2.4.0 for Dell T1500 does not support UEFI/GPT/GUID.) The second disk ada1, now has three FreeBSD slices: 1) ada1s1 with FreeBSD 8.1-RELEASE 2) ada1s2 with FreeBSD 8.2-RELEASE 3) ada1s3 with FreeBSD 8.3-RELEASE I want to install the new FreeBSD 8.4-RELEASE on ada1s1 by overwriting the now existing two first slices. This means that ada1s3, must become ada1s2 instead. Is this possible to do? A very important question is if sysinstall's option Install the FreeBSD Boot Manager detects that I have a FreeBSD 8.3 and detect it as slice 2 on disk 1? So it becomes a boot option when I am rebooting? (Maybe the slice may come up as ad6s2, because AHCI in FreeBSD 8.4 isn't enabled at the time of the install.) If the answer to these questions is yes, then the next two questions arise. Can I mount ada1s2a (FreeBSD 8.3) from the newly installed FreeBSD 8.4 and edit my FreeBSD's 8.3-R /etc/fstab according to the new disk layout, and occasionally run FreeBSD 8.3 without problems? Or do I have to do more to get it to work? The idea behind this kind of 'reverse' disk layout of mine is to have FreeBSD 8.4 as my new default OS. And have FreeBSD 8.3 untouched for configuring FreeBSD 8.4 and booting into it when ever needed. If I can do this as described above, I will have plenty of space on the disk for the future and a new FreeBSD release. Thanks for your interest in my questions, Conny Andersson =-=-=-=-=-=-=-=-=-= Conny Andersson atar...@telia.com =-=-=-=-=-=-=-=-=-= ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
You may want to look into running fsck(8) and its myriad of options fsck did the trick Also make sure you have soft updates enabled on your filesystem and preferably journaled soft updates ..pretty sure I do but I'll double check, thanks. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
So the system panics in ufs_rmdir(). Maybe the filesystem is corrupt? Have you tried to fsck(8) it manually? fsck worked, though I had to boot from a USB image because I couldn't get into single user.. for some odd reason. Even if the filesystem is corrupt, ufs_rmdir() shouldn't panic(), IMHO, but fail gracefully. Hmmm... Yeah, I was pretty surprised. I think I tried it like 3 times to be sure... and yeah, each time... kaboom! Who'd have thought. Do I just post this to the mailing list and hope some benevolent developer stumbles upon it and takes it upon him/herself to fix this, or where do I find the FreeBSD Suggestion Box? I guess I should file a Problem Report and see what happens from there. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
9.2-BETA1 iso is available
Just down loaded the 9.2-BETA1 iso. Thought others would be interested to know it is available. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
On 27/07/2013 19:57, David Noel wrote:
So the system panics in ufs_rmdir(). Maybe the filesystem is
corrupt? Have you tried to fsck(8) it manually?
fsck worked, though I had to boot from a USB image because I couldn't
get into single user.. for some odd reason.
Even if the filesystem is corrupt, ufs_rmdir() shouldn't
panic(), IMHO, but fail gracefully. Hmmm...
Yeah, I was pretty surprised. I think I tried it like 3 times to be
sure... and yeah, each time... kaboom! Who'd have thought. Do I just
post this to the mailing list and hope some benevolent developer
stumbles upon it and takes it upon him/herself to fix this, or where
do I find the FreeBSD Suggestion Box? I guess I should file a Problem
Report and see what happens from there.
I was going to raise an issue when the discussion had died down to a
concensus. I also don't think it's reasonable for the kernel to bomb
when it encounters corruption on a disk.
If you want to patch it yourself, edit sys/ufs/ufs/ufs_vnops.c at around
line 2791 change:
if (dp-i_effnlink 3)
panic(ufs_dirrem: Bad link count %d on parent,
dp-i_effnlink);
To
if (dp-i_effnlink 3) {
error = EINVAL;
goto out;
}
The ufs_link() call has a similar issue.
I can't see why my mod will break anything, but there's always
unintended consequences. By returning invalid argument, any code above
it should already be handling that condition although the user will be
scratching their head wondering what's wrong with it. Returning ENOENT
or EACCES or ENOTDIR may be better (No such directory, Access denied
or Not a valid directory).
The trouble is that it's tricky to test properly without finding a good
way to corrupt the link count :-)
Regards, Frank.
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Re: Delete a directory, crash the system
I was going to raise an issue when the discussion had died down to a
concensus. I also don't think it's reasonable for the kernel to bomb
when it encounters corruption on a disk.
If you want to patch it yourself, edit sys/ufs/ufs/ufs_vnops.c at around
line 2791 change:
if (dp-i_effnlink 3)
panic(ufs_dirrem: Bad link count %d on parent,
dp-i_effnlink);
To
if (dp-i_effnlink 3) {
error = EINVAL;
goto out;
}
The ufs_link() call has a similar issue.
I can't see why my mod will break anything, but there's always
unintended consequences. By returning invalid argument, any code above
it should already be handling that condition although the user will be
scratching their head wondering what's wrong with it. Returning ENOENT
or EACCES or ENOTDIR may be better (No such directory, Access denied
or Not a valid directory).
The trouble is that it's tricky to test properly without finding a good
way to corrupt the link count :-)
Regards, Frank.
Cool. Thanks for the patch!
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Re: Delete a directory, crash the system
On 27/07/2013 20:38, David Noel wrote:
I was going to raise an issue when the discussion had died down to a
concensus. I also don't think it's reasonable for the kernel to bomb
when it encounters corruption on a disk.
If you want to patch it yourself, edit sys/ufs/ufs/ufs_vnops.c at around
line 2791 change:
if (dp-i_effnlink 3)
panic(ufs_dirrem: Bad link count %d on parent,
dp-i_effnlink);
To
if (dp-i_effnlink 3) {
error = EINVAL;
goto out;
}
The ufs_link() call has a similar issue.
I can't see why my mod will break anything, but there's always
unintended consequences. By returning invalid argument, any code above
it should already be handling that condition although the user will be
scratching their head wondering what's wrong with it. Returning ENOENT
or EACCES or ENOTDIR may be better (No such directory, Access denied
or Not a valid directory).
The trouble is that it's tricky to test properly without finding a good
way to corrupt the link count :-)
Regards, Frank.
Cool. Thanks for the patch!
Sorry - forgot to mention that you use it entirely at your own risk!
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Re: Delete a directory, crash the system
On 07/27/13 20:57, David Noel wrote:
So the system panics in ufs_rmdir(). Maybe the filesystem is
corrupt? Have you tried to fsck(8) it manually?
fsck worked, though I had to boot from a USB image because I couldn't
get into single user.. for some odd reason.
Even if the filesystem is corrupt, ufs_rmdir() shouldn't
panic(), IMHO, but fail gracefully. Hmmm...
Yeah, I was pretty surprised. I think I tried it like 3 times to be
sure... and yeah, each time... kaboom! Who'd have thought. Do I just
post this to the mailing list and hope some benevolent developer
stumbles upon it and takes it upon him/herself to fix this, or where
do I find the FreeBSD Suggestion Box? I guess I should file a Problem
Report and see what happens from there.
Maybe you could ask on freebsd-fs@. That's the list where the
filesystem hackers are hanging around.
Basically, from /usr/src/sys/ufs/ufs/ufs_vnops.c:ufs_rmdir():
if (dp-i_effnlink 3)
panic(ufs_dirrem: Bad link count %d on parent, dp-i_effnlink);
if (!ufs_dirempty(ip, dp-i_number, cnp-cn_cred)) {
error = ENOTEMPTY;
goto out;
}
(...)
Basically, the parent directory has less than 3 entries, but
since 2 entries are mandatory (. and ..), the 3rd entry
that is missing must belong to the directory being removed.
This is inconsistent. And if the parent directory is inconsistent,
other bad things could happen. The kernel errs on the side of
caution, and panic()s instead of silently returning EINVAL.
Actually, this is a sensible thing to do in this context.
A more robust file system would halt all processes, and perform
an in-kernel fsck on the filesystem and its internal (in-memory)
structures to repair the damage... and THEN resume the processes.
However, this is a major project, and we don't have a self-healing
filesystem / kernel (... yet). ;-)
-cpghost.
--
Cordula's Web. http://www.cordula.ws/
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Re: Delete a directory, crash the system
Yes. It'd be nice if UFS/FFS would just downgrade things to read-only and not panic. -Adrian ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
FusionIO - Extreme support, 9.1
Hi all, I've 2 IOExtreme 80GB cards that work as a stipe yielding 160GB. These cards use exceptionally fast high quality RAM. I called support about Centos6/FreeBSD support but they said nada. The cards do work in Centos6 and I suspect they just wanted to reduce support load, etc... Does this stuff work in FreeBSD =9.1? Thanks in advance, - aurf ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
where to get the release notes for 9.2
There is a specific feature I need to see if it is in 9.2 or just 10 where can I find the draft release notes for 9.2? ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
On Sat, 27 Jul 2013 13:57:31 -0500, David Noel wrote: So the system panics in ufs_rmdir(). Maybe the filesystem is corrupt? Have you tried to fsck(8) it manually? fsck worked, though I had to boot from a USB image because I couldn't get into single user.. for some odd reason. From your initial description, a _severe_ file system defect seems to be a reasonable assumption. Make sure fsck is run in foreground prior to bringing up the system. The option background_fsck=NO in /etc/rc.conf will make sure you won't encounter this problem again (_if_ it was related to the file system). Always make sure you're booting into a fsck'ed environment. You could also use a S.M.A.R.T. analysis tool such as smartmon (from ports) to make sure the OS didn't panic because of a hard disk defect. I'm just mentioning this because I have sufficient exoerience in this field. :-) Even if the filesystem is corrupt, ufs_rmdir() shouldn't panic(), IMHO, but fail gracefully. Hmmm... Yeah, I was pretty surprised. I think I tried it like 3 times to be sure... and yeah, each time... kaboom! It's really surprising that a (comparable) high-level function could fail in that drastic way, but on the other hand, one would assume that there is a _reason_ for this behaviour. -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Delete a directory, crash the system
And here, kids, you can see the strength of open source
operating system: You can see _why_ something happens. :-)
On Sat, 27 Jul 2013 20:35:09 +0100, Frank Leonhardt wrote:
On 27/07/2013 19:57, David Noel wrote:
So the system panics in ufs_rmdir(). Maybe the filesystem is
corrupt? Have you tried to fsck(8) it manually?
fsck worked, though I had to boot from a USB image because I couldn't
get into single user.. for some odd reason.
Even if the filesystem is corrupt, ufs_rmdir() shouldn't
panic(), IMHO, but fail gracefully. Hmmm...
Yeah, I was pretty surprised. I think I tried it like 3 times to be
sure... and yeah, each time... kaboom! Who'd have thought. Do I just
post this to the mailing list and hope some benevolent developer
stumbles upon it and takes it upon him/herself to fix this, or where
do I find the FreeBSD Suggestion Box? I guess I should file a Problem
Report and see what happens from there.
I was going to raise an issue when the discussion had died down to a
concensus. I also don't think it's reasonable for the kernel to bomb
when it encounters corruption on a disk.
If you want to patch it yourself, edit sys/ufs/ufs/ufs_vnops.c at around
line 2791 change:
if (dp-i_effnlink 3)
panic(ufs_dirrem: Bad link count %d on parent,
dp-i_effnlink);
To
if (dp-i_effnlink 3) {
error = EINVAL;
goto out;
}
The ufs_link() call has a similar issue.
I can't see why my mod will break anything, but there's always
unintended consequences.
One of the core policies usually is to stop _any_ action that
had failed due to a reason that cannot be and make sure it
won't get worse. This can be seen for example in fsck's behaviour:
If there is a massive file system error that cannot be repaired
without further intervention that _could_ destroy data or make
its retrieval harder or impossible, the operator will be requested
to make the decision. There are options to automate this process,
but on the other hand, always assume 'yes' can then be a risk,
as it could prevent recovery. My assumtion is that the developers
chose a similar approach here: We found a situation that should
not be possible, so we stop the system for messing up the file
system even more. This carries the attitude of not hiding a
problem for the sake of convenience by being silent and going
back to the usual work. Of course it is debatable if this is the
right decision in _this_ particular case.
By returning invalid argument, any code above
it should already be handling that condition although the user will be
scratching their head wondering what's wrong with it.
By determining the inode number and using the fsdb tool internal
data about inodes can be examined. Will it also show something
that's basically impossible? :-)
Returning ENOENT
or EACCES or ENOTDIR may be better (No such directory, Access denied
or Not a valid directory).
Depends on the applying definition of those errors.
The trouble is that it's tricky to test properly without finding a good
way to corrupt the link count :-)
There is a _simple_ way to do this, and I have even mentioned it.
Use the fsdb program and manipulate the inode manually. Make
sure that you actually understand that _what_ you are doing there
is creating severe file system inconsistency errors. :-)
--
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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Re: Delete a directory, crash the system
On Sat, 27 Jul 2013 14:57:07 -0700, Adrian Chadd wrote: Yes. It'd be nice if UFS/FFS would just downgrade things to read-only and not panic. That would be possible, but it would confuse programs and users. It's not that you could walk up to the disk drive and flip the write protect switch back... ;-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
