Re: loop_end_io_transfer | |
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sat, 29 Aug 2009, Jari Ruusu wrote: > err=-95 means: > > #define EOPNOTSUPP 95 /* Operation not supported on transport endpoint */ > > bi_rw=0x5 means: > > * bit 0 -- data direction > * If not set, bio is a read from device. If set, it's a write to device. > [snip] > * bit 2 -- barrier > * Insert a serialization point in the IO queue, forcing previously > * submitted IO to be completed before this one is issued. > > Here is what happens: > - File system sends barrier write to loop device. > - Loop encrypts the data (not relevant here). > - Loop device sends barrier write to RAID5 backing device. > - RAID5 backing device not supporting barrier writes at all, so it returns > EOPNOTSUPP error code. > - Loop device prints error code it got from backing device. > - Loop device returns EOPNOTSUPP error code to file system. > - File system realizes that barrier writes do not work on that device, so it > switches off barrier writes. > - File system re-sends the write without barrier. > > Summary: > File system auto-detects that barriers don't work on that particular device. Thanks for the information. > If that error message annoys you, then use that -o nobarrier mount > option. I do not mind at all. I just wanted to be 100% sure that partition will not be corrupted. Gabriel - -- // Gabriel VLASIU // // OpenGPG-KeyID : 0xE684206E // OpenGPG-Fingerprint: 0C3D 9F8B 725D E243 CB3C 8428 796A DB1F E684 206E // OpenGPG-URL : http://www.vlasiu.net/public.key -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFKmSVZeWrbH+aEIG4RAoo/AJ9HK0AmaFL4Prs1CrxEeYFlW13BNQCeN01a dfcCbTpiBd9M4UoJV1tiDbA= =YLM4 -----END PGP SIGNATURE----- - Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/