-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Chris - I'm starting to dig into the fun part of error handling and btrfs_commit_transaction is a minefield right now. I've been thinking about how I would go about recovering from a serious error like an -EIO while writing out or an -ENOMEM in a deep part of the code that it's prohibitively expensive to recover from. Mostly I'm looking for the best way to make calling btrfs_std_error() be functionally equivalent to killing the power on the disk. We already block off new writers, but that's obviously nowhere near enough. We could have an open transaction floating around, uncommitted transactions queued, and then an unrecoverable error hits, forcing us to shut it all down. It seems to me that that a similar method of recovery that I wrote for reiserfs can be used here as well. Am I understanding correctly that if I go through the motions of committing the transaction *except* for updating the tree roots, or maybe even doing that but declining to write the superblocks out, that the transaction essentially doesn't exist on disk? Including the allocations? The in-memory representation will not match what's on disk, but that's what happens with every file system in RO-failure mode. With CoW even for data, data is essentially frozen in time as well. (I suppose with nodatacow that's not true, but that's for another day.) - -Jeff - -- Jeff Mahoney SUSE Labs -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJO58fxAAoJEB57S2MheeWyiH8P/RGfJUCwBoz83vLH5qRfsAzO Rnfjq9/NS+58zh5MGImimr9u6ZuNCfNUEFUDXGnVwF2Er1jHh0orU1pQdvU9XlHv T/vAyZp1s/emwwDPQX0Xo24QNumSzA2u7qnUuUBklq8l+KL99OZCErhu/eJ6i06S vTv6KflsL/EU5ISgro051fVLGep0ZF5hLYOJHQbCJaRlL6OwC2d8cWHGR+qBdRaw t4SQ+tVmKnnd4UzlpPzyQTCSOwdnSYtei28fCAy7X4rmycCXTa8eYQgvxkIabgkM IF8F8utcKT2yTFyUbJM3MWUx0yzPVsL77XnO8FCfYbusYC1EPTnMSGJ1CbupHvr1 kmFJEOQ4rj8fxLzxYDdxjEJ7HtyIhQDfH1BZ1/0+e8BShepr7/60AwoNaWVOceN/ rDDkkKgIogprGO0un1Fv3J+FNPgIR/47t1ULSUTLhg4vAqbQRuYiI36Y2zlG7G2a C/u/4UgrH40CVFVVtIRnjO67/QffTC3pf8Q6kzaXgotQJUt1XfY3a4X6MLQnfWKo bBQaPTIpsxtf7k3cnH5XfjQqtljGgXrbBExtMPKBor7RDPVw3KrLm4F35Enr4Gur pumzXQfiSC2oiSxpG1RXegZ2CXLKW4a/++kMApAOR98xTAHM8dzFhx0V0YZh/MHY Sc+ddgI2v5ZIUL2IV3WK =DmtI -----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
