diff options
| -rw-r--r-- | fs/xfs/xfs_log.c | 115 | ||||
| -rw-r--r-- | fs/xfs/xfs_log.h | 42 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 25 |
3 files changed, 99 insertions, 83 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 1f6e7092ec76..23ca073de6df 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -90,6 +90,62 @@ xlog_iclogs_empty( static int xfs_log_cover(struct xfs_mount *); +/* + * We need to make sure the buffer pointer returned is naturally aligned for the + * biggest basic data type we put into it. We have already accounted for this + * padding when sizing the buffer. + * + * However, this padding does not get written into the log, and hence we have to + * 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. + */ +void * +xlog_prepare_iovec( + struct xfs_log_vec *lv, + struct xfs_log_iovec **vecp, + uint type) +{ + 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); + vec++; + } else { + vec = &lv->lv_iovecp[0]; + } + + 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; + + 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 buf; +} + static void xlog_grant_sub_space( struct xlog *log, @@ -2232,9 +2288,9 @@ 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( @@ -2261,18 +2317,7 @@ 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; } @@ -2282,7 +2327,6 @@ 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; @@ -2500,21 +2544,25 @@ 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, @@ -2532,20 +2580,11 @@ 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++; diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index d1fc43476166..816f44d7dc81 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -21,44 +21,18 @@ struct xfs_log_vec { #define XFS_LOG_VEC_ORDERED (-1) -/* - * We need to make sure the buffer pointer returned is naturally aligned for the - * biggest basic data type we put into it. We have already accounted for this - * padding when sizing the buffer. - * - * However, this padding does not get written into the log, and hence we have to - * 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. - */ -static inline void * -xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp, - uint type) -{ - struct xfs_log_iovec *vec = *vecp; - - if (vec) { - ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs); - vec++; - } else { - 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)); - - 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))); - - *vecp = vec; - return vec->i_addr; -} +void *xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp, + uint type); 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 = cpu_to_be32(len); + + len += sizeof(struct xlog_op_header); lv->lv_buf_len += len; lv->lv_bytes += len; vec->i_len = len; diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 2403a7bbb913..5ccbb6bd4655 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -214,13 +214,20 @@ 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)); /* @@ -465,11 +472,6 @@ 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); @@ -501,6 +503,7 @@ 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 |