The backtrace in your attachment looks like a known bug of 2.6.37 which have already been fixed in 2.6.38. I have no idea why latest btrfs still hang in your environment if there's no debug info... -----Original Message----- From: Maria WikstrÃm [mailto:maria@xxxxxxxxxxxxx] Sent: Friday, February 18, 2011 7:32 PM To: Zhong, Xin Cc: Johannes Hirte; linux-btrfs@xxxxxxxxxxxxxxx Subject: RE: [PATCH v2]Btrfs: pwrite blocked when writing from the mmaped buffer of the same page Seems like my reply got eaten by the lists spam filter, so I resend with attachment compressed. Should have thought of that :p fre 2011-02-11 klockan 12:39 +0800 skrev Zhong, Xin: > Hi, > > Could you paste the output of sysrq+t here? Thanks! Yes, it's in the attachment. I tried latest btrfs from git (last commit Mon Feb 14 00:45:29 2011 +0000) but it hang so bad that I couldn't get the output from sysrq+t to hit the disk. So the output is from vanilla 2.6.37 // Maria > -----Original Message----- > From: Johannes Hirte [mailto:johannes.hirte@xxxxxxxxxxxxxxxxx] > Sent: Wednesday, February 02, 2011 7:35 AM > To: Zhong, Xin > Cc: Maria WikstrÃm; linux-btrfs@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2]Btrfs: pwrite blocked when writing from the > mmaped buffer of the same page > > On Friday 28 January 2011 04:53:24 Zhong, Xin wrote: > > Could you describe the steps to recreate it? > > It will be a great help for me to look further. Thanks! > > It's a little strange. I have to systems with btrfs, both > Gentoo-based. One is affected by this bug the other is not. On the > affected system it is enough to do a 'emerge dev-libs/libgcrypt' that > should normaly compile and install libgcrypt. The emerge command is > part of portage, the package management of Gentoo. > The strace output looks similar to the one from Maria: > ÿô.nlj·Ÿ®‰†+%ŠË±é¥Šwÿº{.nlj·¥Š{±ýžØn‡r¡öë¨è&£ûz¹Þúzf£¢·hšˆ§~††Ûÿÿïÿ‘ê_èæ+v‰¨þ)ßø
