diff options
| author | Alasdair G Kergon <agk@redhat.com> | 2006-03-27 01:17:50 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-27 08:44:59 -0800 |
| commit | 138728dc96529f20dfe970c470e51885a60e329f (patch) | |
| tree | a0369a9de402cd8b9a123129c5e8ba7c69ba1a95 /drivers/md/kcopyd.c | |
| parent | 969429b504ae866d3f8b1cafd68a2c099e305093 (diff) | |
[PATCH] dm snapshot: fix kcopyd destructor
Before removing a snapshot, wait for the completion of any kcopyd jobs using
it.
Do this by maintaining a count (nr_jobs) of how many outstanding jobs each
kcopyd_client has.
The snapshot destructor first unregisters the snapshot so that no new kcopyd
jobs (created by writes to the origin) will reference that particular
snapshot. kcopyd_client_destroy() is now run next to wait for the completion
of any outstanding jobs before the snapshot exception structures (that those
jobs reference) are freed.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/kcopyd.c')
| -rw-r--r-- | drivers/md/kcopyd.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/md/kcopyd.c b/drivers/md/kcopyd.c index 9dcb2c8a385..ed71f3f9462 100644 --- a/drivers/md/kcopyd.c +++ b/drivers/md/kcopyd.c @@ -44,6 +44,9 @@ struct kcopyd_client { struct page_list *pages; unsigned int nr_pages; unsigned int nr_free_pages; + + wait_queue_head_t destroyq; + atomic_t nr_jobs; }; static struct page_list *alloc_pl(void) @@ -292,10 +295,15 @@ static int run_complete_job(struct kcopyd_job *job) int read_err = job->read_err; unsigned int write_err = job->write_err; kcopyd_notify_fn fn = job->fn; + struct kcopyd_client *kc = job->kc; - kcopyd_put_pages(job->kc, job->pages); + kcopyd_put_pages(kc, job->pages); mempool_free(job, _job_pool); fn(read_err, write_err, context); + + if (atomic_dec_and_test(&kc->nr_jobs)) + wake_up(&kc->destroyq); + return 0; } @@ -430,6 +438,7 @@ static void do_work(void *ignored) */ static void dispatch_job(struct kcopyd_job *job) { + atomic_inc(&job->kc->nr_jobs); push(&_pages_jobs, job); wake(); } @@ -669,6 +678,9 @@ int kcopyd_client_create(unsigned int nr_pages, struct kcopyd_client **result) return r; } + init_waitqueue_head(&kc->destroyq); + atomic_set(&kc->nr_jobs, 0); + client_add(kc); *result = kc; return 0; @@ -676,6 +688,9 @@ int kcopyd_client_create(unsigned int nr_pages, struct kcopyd_client **result) void kcopyd_client_destroy(struct kcopyd_client *kc) { + /* Wait for completion of all jobs submitted by this client. */ + wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); + dm_io_put(kc->nr_pages); client_free_pages(kc); client_del(kc); |