Add a new sparse_read operation for the OSD client, driven by its own
state machine. The messenger can repeatedly call the sparse_read
operation, and it will pass back the necessary info to set up to read
the next extent of data, while zeroing in the sparse regions.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
include/linux/ceph/osd_client.h | 37 ++++++++
net/ceph/osd_client.c | 161 +++++++++++++++++++++++++++++++-
2 files changed, 193 insertions(+), 5 deletions(-)
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index 3431011f364d..9405cf3f5b45 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -29,6 +29,42 @@ typedef void (*ceph_osdc_callback_t)(struct ceph_osd_request *);
#define CEPH_HOMELESS_OSD -1
+enum ceph_sparse_read_state {
+ CEPH_SPARSE_READ_COUNT = 0,
+ CEPH_SPARSE_READ_EXTENTS,
+ CEPH_SPARSE_READ_DATA_LEN,
+ CEPH_SPARSE_READ_DATA,
+};
+
+/* A single extent in a SPARSE_READ reply */
+struct ceph_sparse_extent {
+ __le64 off;
+ __le64 len;
+} __attribute__((packed));
+
+/*
+ * A SPARSE_READ reply is a 32-bit count of extents, followed by an array of
+ * 64-bit offset/length pairs, and then all of the actual file data
+ * concatenated after it (sans holes).
+ *
+ * Unfortunately, we don't know how long the extent array is until we've
+ * started reading the data section of the reply, so for a real sparse read, we
+ * have to allocate the array after alloc_msg returns.
+ *
+ * For the common case of a single extent, we keep an embedded extent here so
+ * we can avoid the extra allocation.
+ */
+struct ceph_sparse_read {
+ enum ceph_sparse_read_state sr_state; /* state machine state */
+ u64 sr_offset; /* request obj offset */
+ u64 sr_pos; /* current pos in buffer */
+ int sr_index; /* current extent index */
+ __le32 sr_count; /* number of extents */
+ __le32 sr_datalen; /* length of actual data */
+ struct ceph_sparse_extent *sr_extent; /* extent array */
+ struct ceph_sparse_extent sr_emb_ext[1]; /* extent (for trivial cases */
+};
+
/* a given osd we're communicating with */
struct ceph_osd {
refcount_t o_ref;
@@ -46,6 +82,7 @@ struct ceph_osd {
unsigned long lru_ttl;
struct list_head o_keepalive_item;
struct mutex lock;
+ struct ceph_sparse_read o_sparse_read;
};
#define CEPH_OSD_SLAB_OPS 2
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 1c5815530e0d..602e2315728a 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -376,6 +376,7 @@ static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
switch (op->op) {
case CEPH_OSD_OP_READ:
+ case CEPH_OSD_OP_SPARSE_READ:
case CEPH_OSD_OP_WRITE:
case CEPH_OSD_OP_WRITEFULL:
ceph_osd_data_release(&op->extent.osd_data);
@@ -706,6 +707,7 @@ static void get_num_data_items(struct ceph_osd_request *req,
/* reply */
case CEPH_OSD_OP_STAT:
case CEPH_OSD_OP_READ:
+ case CEPH_OSD_OP_SPARSE_READ:
case CEPH_OSD_OP_LIST_WATCHERS:
*num_reply_data_items += 1;
break;
@@ -775,7 +777,7 @@ void osd_req_op_extent_init(struct ceph_osd_request *osd_req,
BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
opcode != CEPH_OSD_OP_WRITEFULL && opcode != CEPH_OSD_OP_ZERO &&
- opcode != CEPH_OSD_OP_TRUNCATE);
+ opcode != CEPH_OSD_OP_TRUNCATE && opcode != CEPH_OSD_OP_SPARSE_READ);
op->extent.offset = offset;
op->extent.length = length;
@@ -984,6 +986,7 @@ static u32 osd_req_encode_op(struct ceph_osd_op *dst,
case CEPH_OSD_OP_STAT:
break;
case CEPH_OSD_OP_READ:
+ case CEPH_OSD_OP_SPARSE_READ:
case CEPH_OSD_OP_WRITE:
case CEPH_OSD_OP_WRITEFULL:
case CEPH_OSD_OP_ZERO:
@@ -1080,7 +1083,12 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
BUG_ON(opcode != CEPH_OSD_OP_READ && opcode != CEPH_OSD_OP_WRITE &&
opcode != CEPH_OSD_OP_ZERO && opcode != CEPH_OSD_OP_TRUNCATE &&
- opcode != CEPH_OSD_OP_CREATE && opcode != CEPH_OSD_OP_DELETE);
+ opcode != CEPH_OSD_OP_CREATE && opcode != CEPH_OSD_OP_DELETE &&
+ opcode != CEPH_OSD_OP_SPARSE_READ);
+
+ /* can't handle more than one sparse read data item at a time yet */
+ if (WARN_ON_ONCE(opcode == CEPH_OSD_OP_SPARSE_READ && num_ops > 1))
+ return ERR_PTR(-EINVAL);
req = ceph_osdc_alloc_request(osdc, snapc, num_ops, use_mempool,
GFP_NOFS);
@@ -2037,6 +2045,7 @@ static void setup_request_data(struct ceph_osd_request *req)
&op->raw_data_in);
break;
case CEPH_OSD_OP_READ:
+ case CEPH_OSD_OP_SPARSE_READ:
ceph_osdc_msg_data_add(reply_msg,
&op->extent.osd_data);
break;
@@ -2443,6 +2452,20 @@ static void submit_request(struct ceph_osd_request *req, bool wrlocked)
__submit_request(req, wrlocked);
}
+static void ceph_init_sparse_read(struct ceph_sparse_read *sr, u64 offset)
+{
+ if (sr->sr_extent != sr->sr_emb_ext)
+ kfree(sr->sr_extent);
+ sr->sr_state = CEPH_SPARSE_READ_COUNT;
+ sr->sr_offset = offset;
+ sr->sr_pos = 0;
+ sr->sr_count = 0;
+ sr->sr_index = 0;
+ sr->sr_extent = sr->sr_emb_ext;
+ sr->sr_extent[0].off = 0;
+ sr->sr_extent[0].len = 0;
+}
+
static void finish_request(struct ceph_osd_request *req)
{
struct ceph_osd_client *osdc = req->r_osdc;
@@ -2452,8 +2475,10 @@ static void finish_request(struct ceph_osd_request *req)
req->r_end_latency = ktime_get();
- if (req->r_osd)
+ if (req->r_osd) {
+ ceph_init_sparse_read(&req->r_osd->o_sparse_read, 0);
unlink_request(req->r_osd, req);
+ }
atomic_dec(&osdc->num_requests);
/*
@@ -3655,6 +3680,7 @@ static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
struct MOSDOpReply m;
u64 tid = le64_to_cpu(msg->hdr.tid);
u32 data_len = 0;
+ u32 result_len = 0;
int ret;
int i;
@@ -3749,6 +3775,13 @@ static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
req->r_ops[i].rval = m.rval[i];
req->r_ops[i].outdata_len = m.outdata_len[i];
data_len += m.outdata_len[i];
+ if (req->r_ops[i].op == CEPH_OSD_OP_SPARSE_READ) {
+ struct ceph_sparse_read *sr = &osd->o_sparse_read;
+
+ result_len += sr->sr_pos - sr->sr_offset;
+ } else {
+ result_len += m.outdata_len[i];
+ }
}
if (data_len != le32_to_cpu(msg->hdr.data_len)) {
pr_err("sum of lens %u != %u for tid %llu\n", data_len,
@@ -3763,7 +3796,7 @@ static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
* one (type of) reply back.
*/
WARN_ON(!(m.flags & CEPH_OSD_FLAG_ONDISK));
- req->r_result = m.result ?: data_len;
+ req->r_result = m.result ?: result_len;
finish_request(req);
mutex_unlock(&osd->lock);
up_read(&osdc->lock);
@@ -5398,6 +5431,22 @@ static void osd_dispatch(struct ceph_connection *con, struct ceph_msg *msg)
ceph_msg_put(msg);
}
+static bool is_sparse_read(struct ceph_osd_request *req, u64 *off)
+{
+ int i;
+
+ if (!(req->r_flags & CEPH_OSD_FLAG_READ))
+ return false;
+
+ for (i = 0; i < req->r_num_ops; ++i) {
+ if (req->r_ops[i].op == CEPH_OSD_OP_SPARSE_READ) {
+ *off = req->r_ops[i].extent.offset;
+ return true;
+ }
+ }
+ return false;
+}
+
/*
* Lookup and return message for incoming reply. Don't try to do
* anything about a larger than preallocated data portion of the
@@ -5414,6 +5463,8 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
int front_len = le32_to_cpu(hdr->front_len);
int data_len = le32_to_cpu(hdr->data_len);
u64 tid = le64_to_cpu(hdr->tid);
+ u64 sroff;
+ bool sparse;
down_read(&osdc->lock);
if (!osd_registered(osd)) {
@@ -5446,7 +5497,9 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
req->r_reply = m;
}
- if (data_len > req->r_reply->data_length) {
+ sparse = is_sparse_read(req, &sroff);
+
+ if (!sparse && (data_len > req->r_reply->data_length)) {
pr_warn("%s osd%d tid %llu data %d > preallocated %zu, skipping\n",
__func__, osd->o_osd, req->r_tid, data_len,
req->r_reply->data_length);
@@ -5456,6 +5509,10 @@ static struct ceph_msg *get_reply(struct ceph_connection *con,
}
m = ceph_msg_get(req->r_reply);
+ m->sparse_read = sparse;
+ if (sparse)
+ ceph_init_sparse_read(&osd->o_sparse_read, sroff);
+
dout("get_reply tid %lld %p\n", tid, m);
out_unlock_session:
@@ -5688,9 +5745,103 @@ static int osd_check_message_signature(struct ceph_msg *msg)
return ceph_auth_check_message_signature(auth, msg);
}
+static void zero_range(struct ceph_msg *msg, u64 off, u64 len)
+{
+ struct ceph_msg_data_cursor cursor;
+
+ ceph_msg_data_cursor_init(&cursor, msg, off + len);
+
+ while (len) {
+ struct page *page;
+ size_t poff, plen;
+ bool last = false;
+
+ page = ceph_msg_data_next(&cursor, &poff, &plen, &last);
+ if (WARN_ON_ONCE(!page))
+ break;
+ if (plen > len)
+ plen = len;
+ zero_user_segment(page, poff, plen);
+ len -= plen;
+ }
+}
+
+static int osd_sparse_read(struct ceph_connection *con, u64 *poff, u64 *plen, char **pbuf)
+{
+ struct ceph_osd *o = con->private;
+ struct ceph_sparse_read *sr = &o->o_sparse_read;
+ u32 count = __le32_to_cpu(sr->sr_count);
+ u64 eoff, elen;
+
+ switch (sr->sr_state) {
+ case CEPH_SPARSE_READ_COUNT:
+ /* number of extents */
+ *plen = sizeof(sr->sr_count);
+ *pbuf = (char *)&sr->sr_count;
+ sr->sr_state = CEPH_SPARSE_READ_EXTENTS;
+ break;
+ case CEPH_SPARSE_READ_EXTENTS:
+ dout("got %u extents\n", count);
+
+ if (count > 0) {
+ if (count > 1) {
+ /* can't use the embedded extent array */
+ sr->sr_extent = kmalloc_array(count, sizeof(*sr->sr_extent),
+ GFP_NOIO);
+ if (!sr->sr_extent)
+ return -ENOMEM;
+ }
+ *plen = count * sizeof(*sr->sr_extent);
+ *pbuf = (char *)sr->sr_extent;
+ sr->sr_state = CEPH_SPARSE_READ_DATA_LEN;
+ break;
+ }
+ /* No extents? Fall through to reading data len */
+ fallthrough;
+ case CEPH_SPARSE_READ_DATA_LEN:
+ *plen = sizeof(sr->sr_datalen);
+ *pbuf = (char *)&sr->sr_datalen;
+ sr->sr_state = CEPH_SPARSE_READ_DATA;
+ break;
+ case CEPH_SPARSE_READ_DATA:
+ /* on first extent, set last offset to starting pos */
+ if (sr->sr_index == 0)
+ sr->sr_pos = sr->sr_offset;
+
+ if (sr->sr_index >= count) {
+ dout("sr_index %d count %d\n", sr->sr_index, count);
+ return 0;
+ }
+
+ eoff = le64_to_cpu(sr->sr_extent[sr->sr_index].off);
+ elen = le64_to_cpu(sr->sr_extent[sr->sr_index].len);
+
+ dout("ext %d off 0x%llx len 0x%llx\n", sr->sr_index, eoff, elen);
+
+ /* zero out anything from sr_pos to start of extent */
+ if (sr->sr_pos < eoff)
+ zero_range(con->in_msg,
+ sr->sr_pos - sr->sr_offset,
+ eoff - sr->sr_pos);
+
+ /* Pass back extent info for msgr to set up buffer */
+ *poff = eoff - sr->sr_offset;
+ *plen = elen;
+
+ /* Set position for next extent */
+ sr->sr_pos = *poff + elen;
+
+ /* Bump the array index */
+ ++sr->sr_index;
+ break;
+ }
+ return 1;
+}
+
static const struct ceph_connection_operations osd_con_ops = {
.get = osd_get_con,
.put = osd_put_con,
+ .sparse_read = osd_sparse_read,
.alloc_msg = osd_alloc_msg,
.dispatch = osd_dispatch,
.fault = osd_fault,
--
2.34.1
