kernel/git/stable/linux.git/drivers/md/dm-snap.h, branch master

dm snapshot: remove dm_snap header

2009-04-02T18:55:34+00:00

Move some of the last bits from dm-snap.h into dm-snap.c where they belong and remove dm-snap.h. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm snapshot: remove dm_snap header use

2009-04-02T18:55:33+00:00

Move useful functions out of dm-snap.h and stop using dm-snap.h. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm exception store: move cow pointer

2009-04-02T18:55:33+00:00

Move COW device from snapshot to exception store. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm exception store: move chunk_fields

2009-04-02T18:55:32+00:00

Move chunk fields from snapshot to exception store. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm exception store: move dm_target pointer

2009-04-02T18:55:32+00:00

Move target pointer from snapshot to exception store. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm exception store: introduce registry

2009-04-02T18:55:31+00:00

Move exception stores into a registry. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm snapshot: extend exception store functions

2009-01-06T03:05:19+00:00

Supply dm_add_exception as a callback to the read_metadata function. Add a status function ready for a later patch and name the functions consistently. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm snapshot: rename struct exception_store

2009-01-06T03:05:16+00:00

Rename struct exception_store to dm_exception_store. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm snapshot: separate out exception store interface

2009-01-06T03:05:15+00:00

Pull structures that bridge the gap between snapshot and exception store out of dm-snap.h and put them in a new .h file - dm-exception-store.h. This file will define the API for new exception stores. Ultimately, dm-snap.h is unnecessary, since only dm-snap.c should be using it. Signed-off-by: Jonathan Brassow Signed-off-by: Alasdair G Kergon

dm snapshot: wait for chunks in destructor

2008-10-30T13:33:16+00:00

If there are several snapshots sharing an origin and one is removed while the origin is being written to, the snapshot's mempool may get deleted while elements are still referenced. Prior to dm-snapshot-use-per-device-mempools.patch the pending exceptions may still have been referenced after the snapshot was destroyed, but this was not a problem because the shared mempool was still there. This patch fixes the problem by tracking the number of mempool elements in use. The scenario: - You have an origin and two snapshots 1 and 2. - Someone writes to the origin. - It creates two exceptions in the snapshots, snapshot 1 will be primary exception, snapshot 2's pending_exception->primary_pe will point to the exception in snapshot 1. - The exceptions are being relocated, relocation of exception 1 finishes (but it's pending_exception is still allocated, because it is referenced by an exception from snapshot 2) - The user lvremoves snapshot 1 --- it calls just suspend (does nothing) and destructor. md->pending is zero (there is no I/O submitted to the snapshot by md layer), so it won't help us. - The destructor waits for kcopyd jobs to finish on snapshot 1 --- but there are none. - The destructor on snapshot 1 cleans up everything. - The relocation of exception on snapshot 2 finishes, it drops reference on primary_pe. This frees its primary_pe pointer. Primary_pe points to pending exception created for snapshot 1. So it frees memory into non-existing mempool. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon