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path: root/drivers/md/dm-flakey.c
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2013-03-01dm: rename request variables to biosAlasdair G Kergon
Use 'bio' in the name of variables and functions that deal with bios rather than 'request' to avoid confusion with the normal block layer use of 'request'. No functional changes. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-01dm: fix truncated status stringsMikulas Patocka
Avoid returning a truncated table or status string instead of setting the DM_BUFFER_FULL_FLAG when the last target of a table fills the buffer. When processing a table or status request, the function retrieve_status calls ti->type->status. If ti->type->status returns non-zero, retrieve_status assumes that the buffer overflowed and sets DM_BUFFER_FULL_FLAG. However, targets don't return non-zero values from their status method on overflow. Most targets returns always zero. If a buffer overflow happens in a target that is not the last in the table, it gets noticed during the next iteration of the loop in retrieve_status; but if a buffer overflow happens in the last target, it goes unnoticed and erroneously truncated data is returned. In the current code, the targets behave in the following way: * dm-crypt returns -ENOMEM if there is not enough space to store the key, but it returns 0 on all other overflows. * dm-thin returns errors from the status method if a disk error happened. This is incorrect because retrieve_status doesn't check the error code, it assumes that all non-zero values mean buffer overflow. * all the other targets always return 0. This patch changes the ti->type->status function to return void (because most targets don't use the return code). Overflow is detected in retrieve_status: if the status method fills up the remaining space completely, it is assumed that buffer overflow happened. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21dm: remove map_infoMikulas Patocka
This patch removes map_info from bio-based device mapper targets. map_info is still used for request-based targets. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-12-21dm flakey: dont use map_contextMikulas Patocka
Replace map_info with a per-bio structure "struct per_bio_data" in dm-flakey. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-07-27dm thin: commit before gathering statusAlasdair G Kergon
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>
2012-03-28dm: reject trailing characters in sccanf inputMikulas Patocka
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>
2012-03-07dm flakey: fix crash on read when corrupt_bio_byte not setMike Snitzer
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>
2012-01-14dm: do not forward ioctls from logical volumes to the underlying devicePaolo Bonzini
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>
2011-09-25dm: flakey fix corrupt_bio_byte error pathMike Snitzer
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>
2011-08-02dm flakey: add corrupt_bio_byte featureMike Snitzer
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>
2011-08-02dm flakey: add drop_writesMike Snitzer
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>
2011-08-02dm flakey: support feature argsMike Snitzer
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>
2011-08-02dm flakey: use dm_target_offset and support discardsMike Snitzer
Use dm_target_offset() and support discards. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2011-03-24dm: add flakey targetJosef Bacik
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>