drbd: detach from frozen backing device
* drbd-8.3:
documentation: Documented detach's --force and disk's --disk-timeout
drbd: Implemented the disk-timeout option
drbd: Force flag for the detach operation
drbd: Allow new IOs while the local disk in in FAILED state
drbd: Bitmap IO functions can not return prematurely if the disk breaks
drbd: Added a kref to bm_aio_ctx
drbd: Hold a reference to ldev while doing meta-data IO
drbd: Keep a reference to the bio until the completion handler finished
drbd: Implemented wait_until_done_or_disk_failure()
drbd: Replaced md_io_mutex by an atomic: md_io_in_use
drbd: moved md_io into mdev
drbd: Immediately allow completion of IOs, that wait for IO completions on a failed disk
drbd: Keep a reference to barrier acked requests
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index aeb483d..58b5b61 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -114,18 +114,44 @@
static int w_al_write_transaction(struct drbd_work *, int);
+void *drbd_md_get_buffer(struct drbd_conf *mdev)
+{
+ int r;
+
+ wait_event(mdev->misc_wait,
+ (r = atomic_cmpxchg(&mdev->md_io_in_use, 0, 1)) == 0 ||
+ mdev->state.disk <= D_FAILED);
+
+ return r ? NULL : page_address(mdev->md_io_page);
+}
+
+void drbd_md_put_buffer(struct drbd_conf *mdev)
+{
+ if (atomic_dec_and_test(&mdev->md_io_in_use))
+ wake_up(&mdev->misc_wait);
+}
+
+static bool md_io_allowed(struct drbd_conf *mdev)
+{
+ enum drbd_disk_state ds = mdev->state.disk;
+ return ds >= D_NEGOTIATING || ds == D_ATTACHING;
+}
+
+void wait_until_done_or_disk_failure(struct drbd_conf *mdev, unsigned int *done)
+{
+ wait_event(mdev->misc_wait, *done || !md_io_allowed(mdev));
+}
+
static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
struct drbd_backing_dev *bdev,
struct page *page, sector_t sector,
int rw, int size)
{
struct bio *bio;
- struct drbd_md_io md_io;
int err;
- md_io.mdev = mdev;
- init_completion(&md_io.event);
- md_io.error = 0;
+ mdev->md_io.done = 0;
+ mdev->md_io.error = -ENODEV;
if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
rw |= REQ_FUA | REQ_FLUSH;
@@ -137,17 +163,25 @@
err = -EIO;
if (bio_add_page(bio, page, size, 0) != size)
goto out;
- bio->bi_private = &md_io;
+ bio->bi_private = &mdev->md_io;
bio->bi_end_io = drbd_md_io_complete;
bio->bi_rw = rw;
+ if (!get_ldev_if_state(mdev, D_ATTACHING)) { /* Corresponding put_ldev in drbd_md_io_complete() */
+ dev_err(DEV, "ASSERT FAILED: get_ldev_if_state() == 1 in _drbd_md_sync_page_io()\n");
+ err = -ENODEV;
+ goto out;
+ }
+
+ bio_get(bio); /* one bio_put() is in the completion handler */
+ atomic_inc(&mdev->md_io_in_use); /* drbd_md_put_buffer() is in the completion handler */
if (drbd_insert_fault(mdev, (rw & WRITE) ? DRBD_FAULT_MD_WR : DRBD_FAULT_MD_RD))
bio_endio(bio, -EIO);
else
submit_bio(rw, bio);
- wait_for_completion(&md_io.event);
+ wait_until_done_or_disk_failure(mdev, &mdev->md_io.done);
if (bio_flagged(bio, BIO_UPTODATE))
- err = md_io.error;
+ err = mdev->md_io.error;
out:
bio_put(bio);
@@ -160,7 +194,7 @@
int err;
struct page *iop = mdev->md_io_page;
- D_ASSERT(mutex_is_locked(&mdev->md_io_mutex));
+ D_ASSERT(atomic_read(&mdev->md_io_in_use) == 1);
BUG_ON(!bdev->md_bdev);
@@ -344,8 +378,14 @@
return 0;
}
- mutex_lock(&mdev->md_io_mutex); /* protects md_io_buffer, al_tr_cycle, ... */
- buffer = page_address(mdev->md_io_page);
+ buffer = drbd_md_get_buffer(mdev); /* protects md_io_buffer, al_tr_cycle, ... */
+ if (!buffer) {
+ dev_err(DEV, "disk failed while waiting for md_io buffer\n");
+ aw->err = -EIO;
+ complete(&((struct update_al_work *)w)->event);
+ put_ldev(mdev);
+ return 1;
+ }
memset(buffer, 0, sizeof(*buffer));
buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);
@@ -415,7 +455,7 @@
mdev->al_tr_number++;
}
- mutex_unlock(&mdev->md_io_mutex);
+ drbd_md_put_buffer(mdev);
complete(&((struct update_al_work *)w)->event);
put_ldev(mdev);
@@ -506,8 +546,9 @@
/* lock out all other meta data io for now,
* and make sure the page is mapped.
*/
- mutex_lock(&mdev->md_io_mutex);
- b = page_address(mdev->md_io_page);
+ b = drbd_md_get_buffer(mdev);
+ if (!b)
+ return 0;
/* Always use the full ringbuffer space for now.
* possible optimization: read in all of it,
@@ -528,7 +569,7 @@
/* IO error */
if (rv == -1) {
- mutex_unlock(&mdev->md_io_mutex);
+ drbd_md_put_buffer(mdev);
return 0;
}
@@ -558,7 +599,7 @@
if (!found_valid) {
if (found_initialized != mx)
dev_warn(DEV, "No usable activity log found.\n");
- mutex_unlock(&mdev->md_io_mutex);
+ drbd_md_put_buffer(mdev);
return 1;
}
@@ -573,7 +614,7 @@
if (!expect(rv != 0))
goto cancel;
if (rv == -1) {
- mutex_unlock(&mdev->md_io_mutex);
+ drbd_md_put_buffer(mdev);
return 0;
}
@@ -643,7 +684,7 @@
mdev->al_tr_pos = (to + 1) % (MD_AL_SECTORS*512/MD_BLOCK_SIZE);
/* ok, we are done with it */
- mutex_unlock(&mdev->md_io_mutex);
+ drbd_md_put_buffer(mdev);
dev_info(DEV, "Found %d transactions (%d active extents) in activity log.\n",
transactions, active_extents);