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author | Alasdair G Kergon <agk@redhat.com> | 2009-12-10 23:52:23 +0000 |
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committer | Alasdair G Kergon <agk@redhat.com> | 2009-12-10 23:52:23 +0000 |
commit | a794015597a2d9b437470c7692aac77e5fc08cd2 (patch) | |
tree | d25dd56edd53f8f1890ed005b5531ccfa07c28ee /drivers/md/dm-table.c | |
parent | 1d0f3ce83200edc5d43723c77c62b09ad6560294 (diff) | |
download | linux-a794015597a2d9b437470c7692aac77e5fc08cd2.tar.gz |
dm: bind new table before destroying old
When replacing a mapped device's table during a 'resume', delay the destruction of the old table until the new one is successfully in place. This will make it easier for a later patch to transfer internal state information from the old table to the new one (something we do not currently support) while giving us more options for reversion if a later part of the operation fails. Devices are always in the suspended state during dm_swap_table(). This patch reinforces the requirement that all I/O must have been flushed from the table targets while in this state (including any in workqueues). In the case of 'noflush' suspending, unprocessed I/O should have been 'pushed back' to the dm core prior to this point, for resubmission after the new table is in place. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-table.c')
-rw-r--r-- | drivers/md/dm-table.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 1a6cb3c7822e..3162b9c3c3f2 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -237,6 +237,9 @@ void dm_table_destroy(struct dm_table *t) { unsigned int i; + if (!t) + return; + while (atomic_read(&t->holders)) msleep(1); smp_mb(); |