kernel/drivers/md/dm.c, branch linux-2.6.30.y

dm: sysfs skip output when device is being destroyed

2009-07-02T23:50:40Z

commit 4d89b7b4e4726893453d0fb4ddbb5b3e16353994 upstream. Do not process sysfs attributes when device is being destroyed. Otherwise code can cause BUG_ON(test_bit(DMF_FREEING, &md->flags)); in dm_put() call. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

block: move bio list helpers into bio.h

2009-04-15T06:28:09Z

It's used by DM and MD and generally useful, so move the bio list helpers into bio.h. Signed-off-by: Christoph Hellwig Acked-by: Alasdair G Kergon Signed-off-by: Jens Axboe

dm: implement basic barrier support

2009-04-08T23:27:16Z

Barriers are submitted to a worker thread that issues them in-order. The thread is modified so that when it sees a barrier request it waits for all pending IO before the request then submits the barrier and waits for it. (We must wait, otherwise it could be intermixed with following requests.) Errors from the barrier request are recorded in a per-device barrier_error variable. There may be only one barrier request in progress at once. For now, the barrier request is converted to a non-barrier request when sending it to the underlying device. This patch guarantees correct barrier behavior if the underlying device doesn't perform write-back caching. The same requirement existed before barriers were supported in dm. Bottom layer barrier support (sending barriers by target drivers) and handling devices with write-back caches will be done in further patches. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: remove dm_request loop

2009-04-08T23:27:15Z

Remove queue_io return value and a loop in dm_request. IO may be submitted to a worker thread with queue_io(). queue_io() sets DMF_QUEUE_IO_TO_THREAD so that all further IO is queued for the thread. When the thread finishes its work, it clears DMF_QUEUE_IO_TO_THREAD and from this point on, requests are submitted from dm_request again. This will be used for processing barriers. Remove the loop in dm_request. queue_io() can submit I/Os to the worker thread even if DMF_QUEUE_IO_TO_THREAD was not set. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: rework queueing and suspension

2009-04-08T23:27:15Z

Rework shutting down on suspend and document the associated rules. Drop write lock in __split_and_process_bio to allow more processing concurrency. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: simplify dm_request loop

2009-04-08T23:27:14Z

Refactor the code in dm_request(). Require the new DMF_BLOCK_FOR_SUSPEND flag on readahead bios we will discard so we don't drop such bios while processing a barrier. Signed-off-by: Alasdair G Kergon

dm: split DMF_BLOCK_IO flag into two

2009-04-08T23:27:14Z

Split the DMF_BLOCK_IO flag into two. DMF_BLOCK_IO_FOR_SUSPEND is set when I/O must be blocked while suspending a device. DMF_QUEUE_IO_TO_THREAD is set when I/O must be queued to a worker thread for later processing. Signed-off-by: Alasdair G Kergon

dm: rearrange dm_wq_work

2009-04-08T23:27:13Z

Refactor dm_wq_work() to make later patch more readable. Signed-off-by: Alasdair G Kergon

dm: remove limited barrier support

2009-04-08T23:27:13Z

Prepare for full barrier implementation: first remove the restricted support. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon

dm: add integrity support

2009-04-08T23:27:12Z

This patch provides support for data integrity passthrough in the device mapper. - If one or more component devices support integrity an integrity profile is preallocated for the DM device. - If all component devices have compatible profiles the DM device is flagged as capable. - Handle integrity metadata when splitting and cloning bios. Signed-off-by: Martin K. Petersen Signed-off-by: Alasdair G Kergon