-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/21/2011 10:21 PM, Liu Bo wrote: > On 12/22/2011 10:59 AM, Jeff Mahoney wrote: Sorry I haven't > responded to this yet. I started digging right in and I've started > to have some good results. It turns out there's already a > btrfs_cleanup_transaction call that will tear down outstanding > transactions. It's not perfect and I've fixed a few bugs in there, > but it saved me a bunch of effort. I just wished I noticed it a day > before since I had it half implemented myself. :) > > >> Hi Jeff, > >> Yes, it should be, and I wrote this cleanup_transaction where I >> should notice you earlier... Anyway, thanks for your effort. > >> The error handling part has lots of corner cases, so I just pick >> up a brute way to tear down the current transaction in order to >> make the FS RO. Oh, and it's worked great. The brute force method is a good start and will address the most severe problems (and most cases) well. I've decided to ignore most cases of -ENOMEM for now. The biggest bug I ran into so far was calling mutex_lock while holding a spinlock. It was a quick fix. The method I've generally used is to mark the transaction aborted and pass the error up as quickly as possible, cleaning up the local allocations and locks as I go. The transaction gets completed normally, returns an error, isn't committed, and then is destroyed (with others, potentially) when called from in btrfs_commit_transaction. Btrfs makes this super easy since we can just skip all the CoW writes. Thanks! - -Jeff >> thanks, liubo > > This afternoon I started running xfstests on a dm-linear mapped > partition. Halfway through a sufficiently long test, I swap out > the linear mapping to an error mapping. It still crashes, but > somewhat less spectacularly. There are still a ton of BUG_ON's I > need to eliminate as well as work out the usual I/O error-recovery > issue of uninterruptible, unrecoverable writeback contexts and > still-locked pages holding up exit. I'm pretty pleased with the > results so far and am pretty optimistic. > > -Jeff > > >> -- To unsubscribe from this list: send the line "unsubscribe >> linux-btrfs" in the body of a message to >> majordomo@xxxxxxxxxxxxxxx More majordomo info at >> http://vger.kernel.org/majordomo-info.html >> > - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJO8qZBAAoJEB57S2MheeWyCtYP/0+VGdUrdPceYkMGngweINFI Y6K/xzDG2tiogFyb8mVj4XH9xtGoODWiZ+yb2FkRfoqsq1dS34/XzM1Cf1SBgFTu J8xIxv3gVp0lDycV6QqpetNaPPpxDz61LmiFqNRd6bn/usBoYdlyexX3HmPll7Je MS0uAiUVNTJIK+W3qN9BIyvg8F61XFy3SdeCY5dmzClDJft1dgu6mWlHhcKVL7LW uDrX9vldV56qoL6rrNyR/wBVg8rhMxVN5z9qFttWsSpORwZdIOIUdKiTULqnCdvf mzs1yNAsAMTcE0GCLOIWEyiTSZrDlg4nGgZMIDKnzD0GywJDy+qc/9XPL+5WkyaD Z48a6sBCXGhmQsux8iEeGAlTfP5/YJMd2PqaKfFlpSeL2u+Pt6EAFUpEUfXDYRhI aBxzJK7D+GrgduheWTQc2AgeH8ee7bUEe1k+d4+EIWJTq5vKkPWH7x580q0yL+t2 qiLqzSlSTPaCr9tJlQo3d+dHu2L2r43+2qYeHut0JjFtp2dDjWO7AzcQ2JsL0yZR jL0dVT96OsWkmKu/qfvSbFZ6LLR+QrlqBzTgNA4R69nLlUj1f05AVaYvwuVqnIPH QdCf53kaEjvVlRw2WScsRHT1gMY62jmES0glIBgAH9bKAYKADlnzIAW6RSpB8NcO GZoCa+90OHl/kkXWB2eZ =DR3D -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
