I'm ccing Linux kernel because this bug is also present in v2.6. Andrew, Viro: tar --verify (which uses lseek) on SCSI tapes fails with:
tar: /dev/nst0: Warning: Cannot seek: Illegal seek The problem was introduced by Viro's f_pos fixes which added "no_llseek" as the llseek method in st.c. John removed "no_llseek" and things are working again for him. On Wed, Mar 02, 2005 at 06:44:34AM -0500, John L. Males wrote: > Hi Marcello, > > I manage to complete the test using the suggested code change to st.c > you requested. I did the change to 2.4.29. The tar --verify worked, > but discovered a new tape file system bug that I very much believe if > different issue. > First question I would have is this code change test I made to st.c, > is it only a quick means to access the issue for the kernel developers > so they can created a more appropriate fix? > > Second question is your thought for this quick change as a temporary > workaround. I think this is the appropriate fix - AFAICS its legit to perform "llseek" on tapes. Please correct me if I'm wrong. > Third question, would you agree the new tape file system bug I found > that I believe not realted to the tar: /dev/nst0: Warning: Cannot > seek: Illegal seek I should report as a new eMail with one liner > description of problem as subject? Please report that problem separately! > > > Regards, > > John L. Males > Willowdale, Ontario > Canada > 02 March 2005 (06:28 -) 06:44 > 01 March 2005 (14:05 - 20:45) > > > ********** Reply Seperator ********** > > On (Tue) 2005-03-01 11:22:24 -0300 > Marcelo Tosatti wrote in Message-ID: [EMAIL PROTECTED] > > To: "John L. Males" <[EMAIL PROTECTED]> > From: Marcelo Tosatti <[EMAIL PROTECTED]> > Subject: Re: [BUG] 2.4.27 - 2.4.29 tar: /dev/nst0: Warning: Cannot > seek: Illegal seekg > Date: Tue, 1 Mar 2005 11:22:24 -0300 > > > > > Hi John, > > > > I'm very sorry for the delay. > > > > Please do the following: > > > > Edit drivers/char/st.c, line 3871: > > > > static struct file_operations st_fops = > > { > > owner: THIS_MODULE, > > read: st_read, > > write: st_write, > > ioctl: st_ioctl, > > llseek: no_llseek, > > open: st_open, > > flush: st_flush, > > release: st_release, > > }; > > > > Comment out the "llseek" entry: > > > > static struct file_operations st_fops = > > { > > owner: THIS_MODULE, > > read: st_read, > > write: st_write, > > ioctl: st_ioctl, > > // llseek: no_llseek, > > open: st_open, > > flush: st_flush, > > release: st_release, > > }; > > > > And retest. > > > > > > Thanks. > > > > > > On Mon, Feb 28, 2005 at 05:44:44PM -0500, John L. Males wrote: > > > Marcelo, > > > > > > > > ********** Reply Seperator ********** > > > > > > > > > > On (Sat) 2005-02-26 07:50:52 -0300 > > > > > Marcelo Tosatti wrote in Message-ID: > > > > > [EMAIL PROTECTED] > > > > > > > > > > To: "John L. Males" <[EMAIL PROTECTED]> > > > > > From: Marcelo Tosatti <[EMAIL PROTECTED]> > > > > > Subject: Re: Fw[05]: [BUG] 2.4.27 - 2.4.29 tar: /dev/nst0: > > > > > Warning: Cannot seek: Illegal seek > > > > > Date: Sat, 26 Feb 2005 07:50:52 -0300 > > > > > > > > > > > > > > > > > Hi John, > > > > > > > > > > > > On Wed, Feb 23, 2005 at 10:03:08AM -0500, John L. Males > > > > > > wrote: > > > > > > > Marcelo, > > > > > > > > > > > > > > I have tried to post the attached bug to ther LKML about > > > > > > > 13:10 yesterday and it has not posted, nor any message > > > > > > > about why will not. I never had problems posting to the > > > > > > > LKML in past, but it has been a couple years since I did. > > > > > > > My current understanding is bugzilla if for reporting 2.6 > > > > > > > issues and not 2.4 issues. Is this correct? > > > > > > > > > > > > There are some v2.4 bugs reported at the bugzilla, but you > > > > > > are right: bugzilla should be used for 2.6 issues only, I'm > > > > > > personally tracking the v2.4 buglist. > > > > > > > > > > > > That being said, please contact me personally whenever you > > > > > > have a 2.4 bugreport! > > > > > > > > > > > > > I searched high and low to find your eMail address and > > > > > > > with no luck. I eMailed someone that made a patch realted > > > > > > > to tapes just to find out how I can get the bug sent to > > > > > > > you. They gave me your eMail address. I fully understand > > > > > > > the problem of being a Kernel maintainer, not to mention > > > > > > > the SPAM problems why I seemed unable to find your eMail > > > > > > > address listed anywhere. > > > > > > > > > > > > > > A couple updates to the original bug eMail details that > > > > > > > are attached. I do not believe the issue is controller > > > > > > > specific, but just for record the system has two > > > > > > > AHA-2940UW with 2.57.2 firmware. I looked at the delta > > > > > > > patch for 2.4.26 to 2.4.27 and seems there were no AIC7XXX > > > > > > > changes, there seemed to be some tape related changes and > > > > > > > a llseek change. Not sure if that will help narrow the > > > > > > > scope of bug I am experiencing. Someone suggested it was > > > > > > > important issue to report to you and may be "introduced > > > > > > > along with the f_pos race fixes". > > > > > > > > > > > > Ok, can you please try v2.4.27-rc4? The "f_pos race fixes" > > > > > > have been introduced during v2.5. > > > > > > > > > > I can, but will likley be a few days before I have time to > > > > > build and test as a few personal matters arose on Friday that > > > > > will have my attention for a few days. > > > > > > > > > > > > > > > > > In case you confirm that 2.4.27-rc4 works, we should track > > > > > > down the exact change which caused the problem. > > > > > > > > > > > > > If you or someone that needs to have more details of the > > > > > > > problem just eMail me. I am now using the 2.4.29 stock > > > > > > > Kernel with no additional patches. I would think this is > > > > > > > an important issue for those still needing to do tape > > > > > > > backups using tar. Not sure if you have any other reports > > > > > > > of this problem already of if those that do use tar are > > > > > > > using an older kernel and so are not aware of the issue as > > > > > > > yet. > > > > > > > > > > > > Hope you can help tracking this bug down! :) > > > > > > > > > > > > Thanks for your bugreport and sorry for taking so long to > > > > > > answer. > > > > > > > > > > > > Question: the latest v2.6 kernels also show the same problem > > > > > > on tar--verify? > > > > > > > > > > > > > > > > Marcelo I suspect you are still digging through your eMail and > > > > > have not yet seen my eMail "Re[06]: [BUG] 2.4.27 - 2.4.29 > > > > > tar:/dev/nst0: Warning: Cannot seek: Illegal seek" of 25 > > > > > February 2005(17:45 -) 18:30 which answers the above question > > > > > you had related to the 2.6 kernel. I have copied the part of > > > > > the eMail that relates to your 2.6 kernel question below, but > > > > > left the other question I posed as an aside to be answered > > > > > later when you have time from that eMail: > > > > > > > > > > Marcelo, > > > > > > > > > > Just an update. I managed to figure out how to load the > > > > > 2940UW Kernel drivers from Knoppix listed as "CAUTION". Some > > > > > of the AIC7xxx drivers do not work in the early Knoppix > > > > > versions that have a 2.6 kernel in Knoppix. I know you do not > > > > > maintain the 2.6 kernel. I just hought it might be helpful to > > > > > have these observations in realtion to the 2.4 kernel bug I > > > > > reported in case it is helpful. > > > > > > > > > > Using Knoppix: > > > > > > > > > > V3.6 Kernel 2.6.7 tar verify for tape works > > > > > > > > > > V3.7 Kernel 2.6.9 tar verify for tape fails > > > > > > > > > > Looking at the delta patches it seems in the 2.6.8 to 2.6.9 > > > > > patch set there are alot of llseek related changes, many more > > > > > than in the 2.4.26 to 2.4.27 patch set. That said, there were > > > > > very similar llseek patches in 2.4.9 and the 2.4.27 patch sets > > > > > that I suspect may have some relationship to the bug I am > > > > > experiencing. > > > > > > > > > > I would be interested to know if the bug I reported can be > > > > > duplicated and when the patch is created. The latter as > > > > > sometimes reading the change log is is hard for me to deduce > > > > > what the fix description may read like compared to the bug I > > > > > experienced. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/