This is a note to let you know that I've just added the patch titled
dm thin: fix missing out-of-data-space to write mode transition if blocks are released
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-thin-fix-missing-out-of-data-space-to-write-mode-transition-if-blocks-are-released.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2c43fd26e46734430122b8d2ad3024bb532df3ef Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@xxxxxxxxxx>
Date: Thu, 11 Dec 2014 11:12:19 +0000
Subject: dm thin: fix missing out-of-data-space to write mode transition if blocks are released
From: Joe Thornber <ejt@xxxxxxxxxx>
commit 2c43fd26e46734430122b8d2ad3024bb532df3ef upstream.
Discard bios and thin device deletion have the potential to release data
blocks. If the thin-pool is in out-of-data-space mode, and blocks were
released, transition the thin-pool back to full write mode.
The correct time to do this is just after the thin-pool metadata commit.
It cannot be done before the commit because the space maps will not
allow immediate reuse of the data blocks in case there's a rollback
following power failure.
Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-thin.c | 22 ++++++++++++++++++++--
1 file changed, 20 insertions(+), 2 deletions(-)
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -990,6 +990,24 @@ static void schedule_external_copy(struc
schedule_zero(tc, virt_block, data_dest, cell, bio);
}
+static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
+
+static void check_for_space(struct pool *pool)
+{
+ int r;
+ dm_block_t nr_free;
+
+ if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE)
+ return;
+
+ r = dm_pool_get_free_block_count(pool->pmd, &nr_free);
+ if (r)
+ return;
+
+ if (nr_free)
+ set_pool_mode(pool, PM_WRITE);
+}
+
/*
* A non-zero return indicates read_only or fail_io mode.
* Many callers don't care about the return value.
@@ -1004,6 +1022,8 @@ static int commit(struct pool *pool)
r = dm_pool_commit_metadata(pool->pmd);
if (r)
metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
+ else
+ check_for_space(pool);
return r;
}
@@ -1022,8 +1042,6 @@ static void check_low_water_mark(struct
}
}
-static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
-
static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
{
int r;
Patches currently in stable-queue which might be from ejt@xxxxxxxxxx are
queue-3.18/dm-space-map-metadata-fix-sm_bootstrap_get_nr_blocks.patch
queue-3.18/dm-thin-fix-missing-out-of-data-space-to-write-mode-transition-if-blocks-are-released.patch
queue-3.18/dm-cache-fix-spurious-cell_defer-when-dealing-with-partial-block-at-end-of-device.patch
queue-3.18/dm-thin-fix-inability-to-discard-blocks-when-in-out-of-data-space-mode.patch
queue-3.18/dm-cache-only-use-overwrite-optimisation-for-promotion-when-in-writeback-mode.patch
queue-3.18/dm-cache-dirty-flag-was-mistakenly-being-cleared-when-promoting-via-overwrite.patch
--
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