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* dm thin: commit before gathering statusAlasdair G Kergon2012-07-271-1/+1
| | | | | | | | | | | | | | | | Commit outstanding metadata before returning the status for a dm thin pool so that the numbers reported are as up-to-date as possible. The commit is not performed if the device is suspended or if the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target through a new 'status_flags' parameter in the target's dm_status_fn. The userspace dmsetup tool will support the --noflush flag with the 'dmsetup status' and 'dmsetup wait' commands from version 1.02.76 onwards. Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: reject trailing characters in sccanf inputMikulas Patocka2012-03-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Device mapper uses sscanf to convert arguments to numbers. The problem is that the way we use it ignores additional unmatched characters in the scanned string. For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number, but also it will match number with some garbage appended, like "123abc". As a result, device mapper accepts garbage after some numbers. For example the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"' will pass without an error. This patch fixes all sscanf uses in device mapper. It appends "%c" with a pointer to a dummy character variable to every sscanf statement. The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds only if string is a null-terminated number (optionally preceded by some whitespace characters). If there is some character appended after the number, sscanf matches "%c", writes the character to the dummy variable and returns 2. We check the return value for 1 and consequently reject numbers with some garbage appended. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: fix crash on read when corrupt_bio_byte not setMike Snitzer2012-03-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following BUG is hit on the first read that is submitted to a dm flakey test device while the device is "down" if the corrupt_bio_byte feature wasn't requested when the device's table was loaded. Example DM table that will hit this BUG: 0 2097152 flakey 8:0 2048 0 30 This bug was introduced by commit a3998799fb4df0b0af8271a7d50c4269032397aa (dm flakey: add corrupt_bio_byte feature) in v3.1-rc1. BUG: unable to handle kernel paging request at ffff8801cfce3fff IP: [<ffffffffa008c233>] corrupt_bio_data+0x6e/0xae [dm_flakey] PGD 1606063 PUD 0 Oops: 0002 [#1] SMP ... Call Trace: <IRQ> [<ffffffffa008c2b5>] flakey_end_io+0x42/0x48 [dm_flakey] [<ffffffffa00dca98>] clone_endio+0x54/0xb6 [dm_mod] [<ffffffff81130587>] bio_endio+0x2d/0x2f [<ffffffff811c819a>] req_bio_endio+0x96/0x9f [<ffffffff811c94b9>] blk_update_request+0x1dc/0x3a9 [<ffffffff812f5ee2>] ? rcu_read_unlock+0x21/0x23 [<ffffffff811c96a6>] blk_update_bidi_request+0x20/0x6e [<ffffffff811c9713>] blk_end_bidi_request+0x1f/0x5d [<ffffffff811c978d>] blk_end_request+0x10/0x12 [<ffffffff8128f450>] scsi_io_completion+0x1e5/0x4b1 [<ffffffff812882a9>] scsi_finish_command+0xec/0xf5 [<ffffffff8128f830>] scsi_softirq_done+0xff/0x108 [<ffffffff811ce284>] blk_done_softirq+0x84/0x98 [<ffffffff81048d19>] __do_softirq+0xe3/0x1d5 [<ffffffff8138f83f>] ? _raw_spin_lock+0x62/0x69 [<ffffffff810997cf>] ? handle_irq_event+0x4c/0x61 [<ffffffff8139833c>] call_softirq+0x1c/0x30 [<ffffffff81003b37>] do_softirq+0x4b/0xa3 [<ffffffff81048a39>] irq_exit+0x53/0xca [<ffffffff81398acd>] do_IRQ+0x9d/0xb4 [<ffffffff81390333>] common_interrupt+0x73/0x73 ... Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.1+ Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: do not forward ioctls from logical volumes to the underlying devicePaolo Bonzini2012-01-141-1/+10
| | | | | | | | | | | | A logical volume can map to just part of underlying physical volume. In this case, it must be treated like a partition. Based on a patch from Alasdair G Kergon. Cc: Alasdair G Kergon <agk@redhat.com> Cc: dm-devel@redhat.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm: flakey fix corrupt_bio_byte error pathMike Snitzer2011-09-251-1/+3
| | | | | | | | | If no arguments were provided to the corrupt_bio_byte feature an error should be returned immediately. Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: add corrupt_bio_byte featureMike Snitzer2011-08-021-15/+140
| | | | | | | | | Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a specified position with a specified value during intervals when the device is "down". Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: add drop_writesMike Snitzer2011-08-021-8/+55
| | | | | | | | Add 'drop_writes' option to drop writes silently while the device is 'down'. Reads are not touched. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: support feature argsMike Snitzer2011-08-021-19/+64
| | | | | | | | | | | | Add the ability to specify arbitrary feature flags when creating a flakey target. This code uses the same target argument helpers that the multipath target does. Also remove the superfluous 'dm-flakey' prefixes from the error messages, as they already contain the prefix 'flakey'. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm flakey: use dm_target_offset and support discardsMike Snitzer2011-08-021-1/+2
| | | | | | | Use dm_target_offset() and support discards. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: add flakey targetJosef Bacik2011-03-241-0/+212
This target is the same as the linear target except that it returns I/O errors periodically. It's been found useful in simulating failing devices for testing purposes. I needed a dm target to do some failure testing on btrfs's raid code, and Mike pointed me at this. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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