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author | Philipp Reisner <philipp.reisner@linbit.com> | 2010-05-10 16:42:23 +0200 |
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committer | Philipp Reisner <philipp.reisner@linbit.com> | 2010-05-18 02:03:32 +0200 |
commit | 9a25a04c8079725c1b1ab756694a8e0757844b40 (patch) | |
tree | ed8fbbbbd7cb4db7d77531bcd2c046f5bd0170c1 /drivers/block | |
parent | a1c88d0d7aa2ef427f78834c9a3b0a673a19dca6 (diff) | |
download | kernel_samsung_smdk4412-9a25a04c8079725c1b1ab756694a8e0757844b40.zip kernel_samsung_smdk4412-9a25a04c8079725c1b1ab756694a8e0757844b40.tar.gz kernel_samsung_smdk4412-9a25a04c8079725c1b1ab756694a8e0757844b40.tar.bz2 |
drbd: If we detect late that IO got frozen, retry after we thawed.
If we detect late (= after grabing mdev->req_lock) that IO got frozen, we
return 1 to generic_make_request(), which simply will retry to make a
request for that bio.
In the subsequent call of generic_make_request() into drbd_make_request_26()
we sleep in inc_ap_bio().
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'drivers/block')
-rw-r--r-- | drivers/block/drbd/drbd_int.h | 4 | ||||
-rw-r--r-- | drivers/block/drbd/drbd_req.c | 33 |
2 files changed, 28 insertions, 9 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 4b97f30..c194348 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -2223,7 +2223,7 @@ static inline int __inc_ap_bio_cond(struct drbd_conf *mdev) /* I'd like to use wait_event_lock_irq, * but I'm not sure when it got introduced, * and not sure when it has 3 or 4 arguments */ -static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two) +static inline void inc_ap_bio(struct drbd_conf *mdev, int count) { /* compare with after_state_ch, * os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S */ @@ -2245,7 +2245,7 @@ static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two) finish_wait(&mdev->misc_wait, &wait); spin_lock_irq(&mdev->req_lock); } - atomic_add(one_or_two, &mdev->ap_bio_cnt); + atomic_add(count, &mdev->ap_bio_cnt); spin_unlock_irq(&mdev->req_lock); } diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index 343e0e6..3397f11 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -722,6 +722,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio) struct drbd_request *req; int local, remote; int err = -EIO; + int ret = 0; /* allocate outside of all locks; */ req = drbd_req_new(mdev, bio); @@ -784,7 +785,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio) (mdev->state.pdsk == D_INCONSISTENT && mdev->state.conn >= C_CONNECTED)); - if (!(local || remote)) { + if (!(local || remote) && !mdev->state.susp) { dev_err(DEV, "IO ERROR: neither local nor remote disk\n"); goto fail_free_complete; } @@ -810,6 +811,16 @@ allocate_barrier: /* GOOD, everything prepared, grab the spin_lock */ spin_lock_irq(&mdev->req_lock); + if (mdev->state.susp) { + /* If we got suspended, use the retry mechanism of + generic_make_request() to restart processing of this + bio. In the next call to drbd_make_request_26 + we sleep in inc_ap_bio() */ + ret = 1; + spin_unlock_irq(&mdev->req_lock); + goto fail_free_complete; + } + if (remote) { remote = (mdev->state.pdsk == D_UP_TO_DATE || (mdev->state.pdsk == D_INCONSISTENT && @@ -947,12 +958,14 @@ fail_and_free_req: req->private_bio = NULL; put_ldev(mdev); } - bio_endio(bio, err); + if (!ret) + bio_endio(bio, err); + drbd_req_free(req); dec_ap_bio(mdev); kfree(b); - return 0; + return ret; } /* helper function for drbd_make_request @@ -1065,15 +1078,21 @@ int drbd_make_request_26(struct request_queue *q, struct bio *bio) /* we need to get a "reference count" (ap_bio_cnt) * to avoid races with the disconnect/reconnect/suspend code. - * In case we need to split the bio here, we need to get two references + * In case we need to split the bio here, we need to get three references * atomically, otherwise we might deadlock when trying to submit the * second one! */ - inc_ap_bio(mdev, 2); + inc_ap_bio(mdev, 3); D_ASSERT(e_enr == s_enr + 1); - drbd_make_request_common(mdev, &bp->bio1); - drbd_make_request_common(mdev, &bp->bio2); + while (drbd_make_request_common(mdev, &bp->bio1)) + inc_ap_bio(mdev, 1); + + while (drbd_make_request_common(mdev, &bp->bio2)) + inc_ap_bio(mdev, 1); + + dec_ap_bio(mdev); + bio_pair_release(bp); } return 0; |