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Message-Id: <1461586077-11581-5-git-send-email-philipp.reisner@linbit.com>
Date: Mon, 25 Apr 2016 14:07:31 +0200
From: Philipp Reisner <philipp.reisner@...bit.com>
To: Jens Axboe <axboe@...com>, linux-kernel@...r.kernel.org
Cc: drbd-dev@...ts.linbit.com,
Philipp Reisner <philipp.reisner@...bit.com>
Subject: [PATCH 04/30] drbd: Implement handling of thinly provisioned storage on resync target nodes
If during resync we read only zeroes for a range of sectors assume
that these secotors can be discarded on the sync target node.
Signed-off-by: Philipp Reisner <philipp.reisner@...bit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
---
drivers/block/drbd/drbd_int.h | 5 +++
drivers/block/drbd/drbd_main.c | 18 ++++++++
drivers/block/drbd/drbd_protocol.h | 4 ++
drivers/block/drbd/drbd_receiver.c | 88 ++++++++++++++++++++++++++++++++++++--
drivers/block/drbd/drbd_worker.c | 29 ++++++++++++-
5 files changed, 140 insertions(+), 4 deletions(-)
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 7a1cf7e..1a93f4f 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -471,6 +471,9 @@ enum {
/* this originates from application on peer
* (not some resync or verify or other DRBD internal request) */
__EE_APPLICATION,
+
+ /* If it contains only 0 bytes, send back P_RS_DEALLOCATED */
+ __EE_RS_THIN_REQ,
};
#define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
#define EE_MAY_SET_IN_SYNC (1<<__EE_MAY_SET_IN_SYNC)
@@ -485,6 +488,7 @@ enum {
#define EE_SUBMITTED (1<<__EE_SUBMITTED)
#define EE_WRITE (1<<__EE_WRITE)
#define EE_APPLICATION (1<<__EE_APPLICATION)
+#define EE_RS_THIN_REQ (1<<__EE_RS_THIN_REQ)
/* flag bits per device */
enum {
@@ -1123,6 +1127,7 @@ extern int drbd_send_ov_request(struct drbd_peer_device *, sector_t sector, int
extern int drbd_send_bitmap(struct drbd_device *device);
extern void drbd_send_sr_reply(struct drbd_peer_device *, enum drbd_state_rv retcode);
extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_state_rv retcode);
+extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *);
extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev);
extern void drbd_device_cleanup(struct drbd_device *device);
void drbd_print_uuids(struct drbd_device *device, const char *text);
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 802d729..3cecc4f 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1377,6 +1377,22 @@ int drbd_send_ack_ex(struct drbd_peer_device *peer_device, enum drbd_packet cmd,
cpu_to_be64(block_id));
}
+int drbd_send_rs_deallocated(struct drbd_peer_device *peer_device,
+ struct drbd_peer_request *peer_req)
+{
+ struct drbd_socket *sock;
+ struct p_block_desc *p;
+
+ sock = &peer_device->connection->data;
+ p = drbd_prepare_command(peer_device, sock);
+ if (!p)
+ return -EIO;
+ p->sector = cpu_to_be64(peer_req->i.sector);
+ p->blksize = cpu_to_be32(peer_req->i.size);
+ p->pad = 0;
+ return drbd_send_command(peer_device, sock, P_RS_DEALLOCATED, sizeof(*p), NULL, 0);
+}
+
int drbd_send_drequest(struct drbd_peer_device *peer_device, int cmd,
sector_t sector, int size, u64 block_id)
{
@@ -3681,6 +3697,8 @@ const char *cmdname(enum drbd_packet cmd)
[P_CONN_ST_CHG_REPLY] = "conn_st_chg_reply",
[P_RETRY_WRITE] = "retry_write",
[P_PROTOCOL_UPDATE] = "protocol_update",
+ [P_RS_THIN_REQ] = "rs_thin_req",
+ [P_RS_DEALLOCATED] = "rs_deallocated",
/* enum drbd_packet, but not commands - obsoleted flags:
* P_MAY_IGNORE
diff --git a/drivers/block/drbd/drbd_protocol.h b/drivers/block/drbd/drbd_protocol.h
index ef92453..e5e74e3 100644
--- a/drivers/block/drbd/drbd_protocol.h
+++ b/drivers/block/drbd/drbd_protocol.h
@@ -60,6 +60,10 @@ enum drbd_packet {
* which is why I chose TRIM here, to disambiguate. */
P_TRIM = 0x31,
+ /* Only use these two if both support FF_THIN_RESYNC */
+ P_RS_THIN_REQ = 0x32, /* Request a block for resync or reply P_RS_DEALLOCATED */
+ P_RS_DEALLOCATED = 0x33, /* Contains only zeros on sync source node */
+
P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
P_MAX_OPT_CMD = 0x101,
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 8b30ab5..3a6c2ec 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1417,9 +1417,15 @@ int drbd_submit_peer_request(struct drbd_device *device,
* so we can find it to present it in debugfs */
peer_req->submit_jif = jiffies;
peer_req->flags |= EE_SUBMITTED;
- spin_lock_irq(&device->resource->req_lock);
- list_add_tail(&peer_req->w.list, &device->active_ee);
- spin_unlock_irq(&device->resource->req_lock);
+
+ /* If this was a resync request from receive_rs_deallocated(),
+ * it is already on the sync_ee list */
+ if (list_empty(&peer_req->w.list)) {
+ spin_lock_irq(&device->resource->req_lock);
+ list_add_tail(&peer_req->w.list, &device->active_ee);
+ spin_unlock_irq(&device->resource->req_lock);
+ }
+
if (blkdev_issue_zeroout(device->ldev->backing_bdev,
sector, data_size >> 9, GFP_NOIO, false))
peer_req->flags |= EE_WAS_ERROR;
@@ -2574,6 +2580,7 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
case P_DATA_REQUEST:
drbd_send_ack_rp(peer_device, P_NEG_DREPLY, p);
break;
+ case P_RS_THIN_REQ:
case P_RS_DATA_REQUEST:
case P_CSUM_RS_REQUEST:
case P_OV_REQUEST:
@@ -2613,6 +2620,12 @@ static int receive_DataRequest(struct drbd_connection *connection, struct packet
peer_req->flags |= EE_APPLICATION;
goto submit;
+ case P_RS_THIN_REQ:
+ /* If at some point in the future we have a smart way to
+ find out if this data block is completely deallocated,
+ then we would do something smarter here than reading
+ the block... */
+ peer_req->flags |= EE_RS_THIN_REQ;
case P_RS_DATA_REQUEST:
peer_req->w.cb = w_e_end_rsdata_req;
fault_type = DRBD_FAULT_RS_RD;
@@ -4587,6 +4600,72 @@ static int receive_out_of_sync(struct drbd_connection *connection, struct packet
return 0;
}
+static int receive_rs_deallocated(struct drbd_connection *connection, struct packet_info *pi)
+{
+ struct drbd_peer_device *peer_device;
+ struct p_block_desc *p = pi->data;
+ struct drbd_device *device;
+ sector_t sector;
+ int size, err = 0;
+
+ peer_device = conn_peer_device(connection, pi->vnr);
+ if (!peer_device)
+ return -EIO;
+ device = peer_device->device;
+
+ sector = be64_to_cpu(p->sector);
+ size = be32_to_cpu(p->blksize);
+
+ dec_rs_pending(device);
+
+ if (get_ldev(device)) {
+ struct drbd_peer_request *peer_req;
+ const int rw = REQ_WRITE | REQ_DISCARD;
+
+ peer_req = drbd_alloc_peer_req(peer_device, ID_SYNCER, sector,
+ size, false, GFP_NOIO);
+ if (!peer_req) {
+ put_ldev(device);
+ return -ENOMEM;
+ }
+
+ peer_req->w.cb = e_end_resync_block;
+ peer_req->submit_jif = jiffies;
+ peer_req->flags |= EE_IS_TRIM;
+
+ spin_lock_irq(&device->resource->req_lock);
+ list_add_tail(&peer_req->w.list, &device->sync_ee);
+ spin_unlock_irq(&device->resource->req_lock);
+
+ atomic_add(pi->size >> 9, &device->rs_sect_ev);
+ err = drbd_submit_peer_request(device, peer_req, rw, DRBD_FAULT_RS_WR);
+
+ if (err) {
+ spin_lock_irq(&device->resource->req_lock);
+ list_del(&peer_req->w.list);
+ spin_unlock_irq(&device->resource->req_lock);
+
+ drbd_free_peer_req(device, peer_req);
+ put_ldev(device);
+ err = 0;
+ goto fail;
+ }
+
+ inc_unacked(device);
+
+ /* No put_ldev() here. Gets called in drbd_endio_write_sec_final(),
+ as well as drbd_rs_complete_io() */
+ } else {
+ fail:
+ drbd_rs_complete_io(device, sector);
+ drbd_send_ack_ex(peer_device, P_NEG_ACK, sector, size, ID_SYNCER);
+ }
+
+ atomic_add(size >> 9, &device->rs_sect_in);
+
+ return err;
+}
+
struct data_cmd {
int expect_payload;
size_t pkt_size;
@@ -4614,11 +4693,14 @@ static struct data_cmd drbd_cmd_handler[] = {
[P_OV_REQUEST] = { 0, sizeof(struct p_block_req), receive_DataRequest },
[P_OV_REPLY] = { 1, sizeof(struct p_block_req), receive_DataRequest },
[P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), receive_DataRequest },
+ [P_RS_THIN_REQ] = { 0, sizeof(struct p_block_req), receive_DataRequest },
[P_DELAY_PROBE] = { 0, sizeof(struct p_delay_probe93), receive_skip },
[P_OUT_OF_SYNC] = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
[P_CONN_ST_CHG_REQ] = { 0, sizeof(struct p_req_state), receive_req_conn_state },
[P_PROTOCOL_UPDATE] = { 1, sizeof(struct p_protocol), receive_protocol },
[P_TRIM] = { 0, sizeof(struct p_trim), receive_Data },
+ [P_RS_DEALLOCATED] = { 0, sizeof(struct p_block_desc), receive_rs_deallocated },
+
};
static void drbdd(struct drbd_connection *connection)
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 4d87499..01d74ee2 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1035,6 +1035,30 @@ int w_e_end_data_req(struct drbd_work *w, int cancel)
return err;
}
+static bool all_zero(struct drbd_peer_request *peer_req)
+{
+ struct page *page = peer_req->pages;
+ unsigned int len = peer_req->i.size;
+
+ page_chain_for_each(page) {
+ unsigned int l = min_t(unsigned int, len, PAGE_SIZE);
+ unsigned int i, words = l / sizeof(long);
+ unsigned long *d;
+
+ d = kmap_atomic(page);
+ for (i = 0; i < words; i++) {
+ if (d[i]) {
+ kunmap_atomic(d);
+ return false;
+ }
+ }
+ kunmap_atomic(d);
+ len -= l;
+ }
+
+ return true;
+}
+
/**
* w_e_end_rsdata_req() - Worker callback to send a P_RS_DATA_REPLY packet in response to a P_RS_DATA_REQUEST
* @w: work object.
@@ -1063,7 +1087,10 @@ int w_e_end_rsdata_req(struct drbd_work *w, int cancel)
} else if (likely((peer_req->flags & EE_WAS_ERROR) == 0)) {
if (likely(device->state.pdsk >= D_INCONSISTENT)) {
inc_rs_pending(device);
- err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
+ if (peer_req->flags & EE_RS_THIN_REQ && all_zero(peer_req))
+ err = drbd_send_rs_deallocated(peer_device, peer_req);
+ else
+ err = drbd_send_block(peer_device, P_RS_DATA_REPLY, peer_req);
} else {
if (__ratelimit(&drbd_ratelimit_state))
drbd_err(device, "Not sending RSDataReply, "
--
1.9.1
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