linux/drivers/md/raid5-cache.c, branch v4.5

raid5-cache: handle journal hotadd in quiesce

2016-01-14T00:49:43Z

Handle journal hotadd in quiesce to avoid creating duplicated threads. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown

md: set MD_HAS_JOURNAL in correct places

2016-01-14T00:49:43Z

Set MD_HAS_JOURNAL when a array is loaded or journal is initialized. This is to avoid the flags set too early in journal disk hotadd. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown

raid5: allow r5l_io_unit allocations to fail

2016-01-06T00:40:12Z

And propagate the error up the stack so we can add the stripe to no_stripes_list and retry our log operation later. This avoids blocking raid5d due to reclaim, an it allows to get rid of the deadlock-prone GFP_NOFAIL allocation. shli: add missing mempool_destroy() Signed-off-by: Christoph Hellwig Signed-off-by: NeilBrown

raid5-cache: use a mempool for the metadata block

2016-01-06T00:40:08Z

We only have a limited number in flight, so use a page based mempool. Signed-off-by: Christoph Hellwig Signed-off-by: NeilBrown

raid5-cache: use a bio_set

2016-01-06T00:40:04Z

This allows us to make guaranteed forward progress. Signed-off-by: Christoph Hellwig Signed-off-by: NeilBrown

raid5-cache: add journal hot add/remove support

2016-01-06T00:39:57Z

Add support for journal disk hot add/remove. Mostly trival checks in md part. The raid5 part is a little tricky. For hot-remove, we can't wait pending write as it's called from raid5d. The wait will cause deadlock. We simplily fail the hot-remove. A hot-remove retry can success eventually since if journal disk is faulty all pending write will be failed and finish. For hot-add, since an array supporting journal but without journal disk will be marked read-only, we are safe to hot add journal without stopping IO (should be read IO, while journal only handles write IO). Signed-off-by: Shaohua Li Signed-off-by: NeilBrown

raid5-cache: free meta_page earlier

2016-01-06T00:39:43Z

Once the I/O completed we don't need the meta page anymore. As the iounits can live on for a long time this reduces memory pressure a bit. Signed-off-by: Christoph Hellwig Reviewed-by: Shaohua Li Signed-off-by: NeilBrown

raid5-cache: simplify r5l_move_io_unit_list

2016-01-06T00:39:34Z

It's only used for one kind of move, so make that explicit. Also clean up the code a bit by using list_for_each_safe. Signed-off-by: Christoph Hellwig Reviewed-by: Shaohua Li Signed-off-by: NeilBrown

raid5-cache: start raid5 readonly if journal is missing

2015-11-01T02:48:29Z

If raid array is expected to have journal (eg, journal is set in MD superblock feature map) and the array is started without journal disk, start the array readonly. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown

raid5-cache: IO error handling

2015-11-01T02:48:29Z

There are 3 places the raid5-cache dispatches IO. The discard IO error doesn't matter, so we ignore it. The superblock write IO error can be handled in MD core. The remaining are log write and flush. When the IO error happens, we mark log disk faulty and fail all write IO. Read IO is still allowed to run. Userspace will get a notification too and corresponding daemon can choose setting raid array readonly for example. Signed-off-by: Shaohua Li Signed-off-by: NeilBrown