@@ -2205,9 +2205,9 @@ xlog_print_trans(
}
/*
- * Calculate the potential space needed by the log vector. If this is a start
- * transaction, the caller has already accounted for both opheaders in the start
- * transaction, so we don't need to account for them here.
+ * Calculate the potential space needed by the log vector. All regions contain
+ * their own opheaders and they are accounted for in region space so we don't
+ * need to add them to the vector length here.
*/
static int
xlog_write_calc_vec_length(
@@ -2234,18 +2234,7 @@ xlog_write_calc_vec_length(
xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
}
}
-
- /* Don't account for regions with embedded ophdrs */
- if (optype && headers > 0) {
- headers--;
- if (optype & XLOG_START_TRANS) {
- ASSERT(headers >= 1);
- headers--;
- }
- }
-
ticket->t_res_num_ophdrs += headers;
- len += headers * sizeof(struct xlog_op_header);
return len;
}
@@ -2255,7 +2244,6 @@ xlog_write_setup_ophdr(
struct xlog_op_header *ophdr,
struct xlog_ticket *ticket)
{
- ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
ophdr->oh_clientid = XFS_TRANSACTION;
ophdr->oh_res2 = 0;
ophdr->oh_flags = 0;
@@ -2489,21 +2477,25 @@ xlog_write(
ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
/*
- * The XLOG_START_TRANS has embedded ophdrs for the
- * start record and transaction header. They will always
- * be the first two regions in the lv chain. Commit and
- * unmount records also have embedded ophdrs.
+ * Regions always have their ophdr at the start of the
+ * region, except for:
+ * - a transaction start which has a start record ophdr
+ * before the first region ophdr; and
+ * - the previous region didn't fully fit into an iclog
+ * so needs a continuation ophdr to prepend the region
+ * in this new iclog.
*/
- if (optype) {
- ophdr = reg->i_addr;
- if (index)
- optype &= ~XLOG_START_TRANS;
- } else {
+ ophdr = reg->i_addr;
+ if (optype && index) {
+ optype &= ~XLOG_START_TRANS;
+ } else if (partial_copy) {
ophdr = xlog_write_setup_ophdr(ptr, ticket);
xlog_write_adv_cnt(&ptr, &len, &log_offset,
sizeof(struct xlog_op_header));
added_ophdr = true;
}
+ ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
+
len += xlog_write_setup_copy(ticket, ophdr,
iclog->ic_size-log_offset,
reg->i_len,
@@ -2521,20 +2513,11 @@ xlog_write(
ophdr->oh_len = cpu_to_be32(copy_len -
sizeof(struct xlog_op_header));
}
- /*
- * Copy region.
- *
- * Commit records just log an opheader, so
- * we can have empty payloads with no data region to
- * copy. Hence we only copy the payload if the vector
- * says it has data to copy.
- */
- ASSERT(copy_len >= 0);
- if (copy_len > 0) {
- memcpy(ptr, reg->i_addr + copy_off, copy_len);
- xlog_write_adv_cnt(&ptr, &len, &log_offset,
- copy_len);
- }
+
+ ASSERT(copy_len > 0);
+ memcpy(ptr, reg->i_addr + copy_off, copy_len);
+ xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len);
+
if (added_ophdr)
copy_len += sizeof(struct xlog_op_header);
record_cnt++;
@@ -30,12 +30,22 @@ struct xfs_log_vec {
* track the space used by the log vectors separately to prevent log space hangs
* due to inaccurate accounting (i.e. a leak) of the used log space through the
* CIL context ticket.
+ *
+ * We also add space for the xlog_op_header that describes this region in the
+ * log. This prepends the data region we return to the caller to copy their data
+ * into, so do all the static initialisation of the ophdr now. Because the ophdr
+ * is not 8 byte aligned, we have to be careful to ensure that we align the
+ * start of the buffer such that the region we return to the call is 8 byte
+ * aligned and packed against the tail of the ophdr.
*/
static inline void *
xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
uint type)
{
- struct xfs_log_iovec *vec = *vecp;
+ struct xfs_log_iovec *vec = *vecp;
+ struct xlog_op_header *oph;
+ uint32_t len;
+ void *buf;
if (vec) {
ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
@@ -44,21 +54,36 @@ xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
vec = &lv->lv_iovecp[0];
}
- if (!IS_ALIGNED(lv->lv_buf_len, sizeof(uint64_t)))
- lv->lv_buf_len = round_up(lv->lv_buf_len, sizeof(uint64_t));
+ len = lv->lv_buf_len + sizeof(struct xlog_op_header);
+ if (!IS_ALIGNED(len, sizeof(uint64_t))) {
+ lv->lv_buf_len = round_up(len, sizeof(uint64_t)) -
+ sizeof(struct xlog_op_header);
+ }
vec->i_type = type;
vec->i_addr = lv->lv_buf + lv->lv_buf_len;
- ASSERT(IS_ALIGNED((unsigned long)vec->i_addr, sizeof(uint64_t)));
+ oph = vec->i_addr;
+ oph->oh_clientid = XFS_TRANSACTION;
+ oph->oh_res2 = 0;
+ oph->oh_flags = 0;
+
+ buf = vec->i_addr + sizeof(struct xlog_op_header);
+ ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t)));
*vecp = vec;
- return vec->i_addr;
+ return buf;
}
static inline void
xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
{
+ struct xlog_op_header *oph = vec->i_addr;
+
+ /* opheader tracks payload length, logvec tracks region length */
+ oph->oh_len = len;
+
+ len += sizeof(struct xlog_op_header);
lv->lv_buf_len += len;
lv->lv_bytes += len;
vec->i_len = len;
@@ -181,13 +181,20 @@ xlog_cil_alloc_shadow_bufs(
}
/*
- * We 64-bit align the length of each iovec so that the start
- * of the next one is naturally aligned. We'll need to
- * account for that slack space here. Then round nbytes up
- * to 64-bit alignment so that the initial buffer alignment is
- * easy to calculate and verify.
+ * We 64-bit align the length of each iovec so that the start of
+ * the next one is naturally aligned. We'll need to account for
+ * that slack space here.
+ *
+ * We also add the xlog_op_header to each region when
+ * formatting, but that's not accounted to the size of the item
+ * at this point. Hence we'll need an addition number of bytes
+ * for each vector to hold an opheader.
+ *
+ * Then round nbytes up to 64-bit alignment so that the initial
+ * buffer alignment is easy to calculate and verify.
*/
- nbytes += niovecs * sizeof(uint64_t);
+ nbytes += niovecs * (sizeof(uint64_t) +
+ sizeof(struct xlog_op_header));;
nbytes = round_up(nbytes, sizeof(uint64_t));
/*
@@ -433,11 +440,6 @@ xlog_cil_insert_items(
spin_lock(&cil->xc_cil_lock);
- /* account for space used by new iovec headers */
- iovhdr_res = diff_iovecs * sizeof(xlog_op_header_t);
- len += iovhdr_res;
- ctx->nvecs += diff_iovecs;
-
/* attach the transaction to the CIL if it has any busy extents */
if (!list_empty(&tp->t_busy))
list_splice_init(&tp->t_busy, &ctx->busy_extents);
@@ -469,6 +471,7 @@ xlog_cil_insert_items(
}
tp->t_ticket->t_curr_res -= len;
ctx->space_used += len;
+ ctx->nvecs += diff_iovecs;
/*
* If we've overrun the reservation, dump the tx details before we move