X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_log_cil.c;h=a844f77d2cc3e199a9959ddb7eb4d9c8df6c9ee1;hb=d420e5c810bce5debce0238021b410d0ef99cf08;hp=02b9cf3f8252baeade5d4e99b3e88853a7b50b98;hpb=1f9c52e16b5f67131440ddd51bd0cff27e45ea10;p=deliverable%2Flinux.git diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 02b9cf3f8252..a844f77d2cc3 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -17,7 +17,7 @@ #include "xfs.h" #include "xfs_fs.h" -#include "xfs_types.h" +#include "xfs_shared.h" #include "xfs_log.h" #include "xfs_trans.h" #include "xfs_trans_priv.h" @@ -80,6 +80,83 @@ xlog_cil_init_post_recovery( log->l_curr_block); } +STATIC int +xlog_cil_lv_item_format( + struct xfs_log_item *lip, + struct xfs_log_vec *lv) +{ + int index; + char *ptr; + + /* format new vectors into array */ + lip->li_ops->iop_format(lip, lv->lv_iovecp); + + /* copy data into existing array */ + ptr = lv->lv_buf; + for (index = 0; index < lv->lv_niovecs; index++) { + struct xfs_log_iovec *vec = &lv->lv_iovecp[index]; + + memcpy(ptr, vec->i_addr, vec->i_len); + vec->i_addr = ptr; + ptr += vec->i_len; + } + + /* + * some size calculations for log vectors over-estimate, so the caller + * doesn't know the amount of space actually used by the item. Return + * the byte count to the caller so they can check and store it + * appropriately. + */ + return ptr - lv->lv_buf; +} + +/* + * Prepare the log item for insertion into the CIL. Calculate the difference in + * log space and vectors it will consume, and if it is a new item pin it as + * well. + */ +STATIC void +xfs_cil_prepare_item( + struct xlog *log, + struct xfs_log_vec *lv, + struct xfs_log_vec *old_lv, + int *diff_len, + int *diff_iovecs) +{ + /* Account for the new LV being passed in */ + if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) { + *diff_len += lv->lv_buf_len; + *diff_iovecs += lv->lv_niovecs; + } + + /* + * If there is no old LV, this is the first time we've seen the item in + * this CIL context and so we need to pin it. If we are replacing the + * old_lv, then remove the space it accounts for and free it. + */ + if (!old_lv) + lv->lv_item->li_ops->iop_pin(lv->lv_item); + else if (old_lv != lv) { + ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED); + + *diff_len -= old_lv->lv_buf_len; + *diff_iovecs -= old_lv->lv_niovecs; + kmem_free(old_lv); + } + + /* attach new log vector to log item */ + lv->lv_item->li_lv = lv; + + /* + * If this is the first time the item is being committed to the + * CIL, store the sequence number on the log item so we can + * tell in future commits whether this is the first checkpoint + * the item is being committed into. + */ + if (!lv->lv_item->li_seq) + lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence; +} + /* * Format log item into a flat buffers * @@ -106,35 +183,39 @@ xlog_cil_init_post_recovery( * format the regions into the iclog as though they are being formatted * directly out of the objects themselves. */ -static struct xfs_log_vec * -xlog_cil_prepare_log_vecs( - struct xfs_trans *tp) +static void +xlog_cil_insert_format_items( + struct xlog *log, + struct xfs_trans *tp, + int *diff_len, + int *diff_iovecs) { struct xfs_log_item_desc *lidp; - struct xfs_log_vec *lv = NULL; - struct xfs_log_vec *ret_lv = NULL; /* Bail out if we didn't find a log item. */ if (list_empty(&tp->t_items)) { ASSERT(0); - return NULL; + return; } list_for_each_entry(lidp, &tp->t_items, lid_trans) { - struct xfs_log_vec *new_lv; - void *ptr; - int index; - int len = 0; - uint niovecs; + struct xfs_log_item *lip = lidp->lid_item; + struct xfs_log_vec *lv; + struct xfs_log_vec *old_lv; + int niovecs = 0; + int nbytes = 0; + int buf_size; bool ordered = false; /* Skip items which aren't dirty in this transaction. */ if (!(lidp->lid_flags & XFS_LID_DIRTY)) continue; + /* get number of vecs and size of data to be stored */ + lip->li_ops->iop_size(lip, &niovecs, &nbytes); + /* Skip items that do not have any vectors for writing */ - niovecs = IOP_SIZE(lidp->lid_item); if (!niovecs) continue; @@ -146,109 +227,63 @@ xlog_cil_prepare_log_vecs( if (niovecs == XFS_LOG_VEC_ORDERED) { ordered = true; niovecs = 0; + nbytes = 0; } - new_lv = kmem_zalloc(sizeof(*new_lv) + - niovecs * sizeof(struct xfs_log_iovec), - KM_SLEEP|KM_NOFS); + /* grab the old item if it exists for reservation accounting */ + old_lv = lip->li_lv; - new_lv->lv_item = lidp->lid_item; - new_lv->lv_niovecs = niovecs; - if (ordered) { - /* track as an ordered logvec */ - new_lv->lv_buf_len = XFS_LOG_VEC_ORDERED; - goto next; - } + /* calc buffer size */ + buf_size = sizeof(struct xfs_log_vec) + nbytes + + niovecs * sizeof(struct xfs_log_iovec); - /* The allocated iovec region lies beyond the log vector. */ - new_lv->lv_iovecp = (struct xfs_log_iovec *)&new_lv[1]; + /* compare to existing item size */ + if (lip->li_lv && buf_size <= lip->li_lv->lv_size) { + /* same or smaller, optimise common overwrite case */ + lv = lip->li_lv; + lv->lv_next = NULL; - /* build the vector array and calculate it's length */ - IOP_FORMAT(new_lv->lv_item, new_lv->lv_iovecp); - for (index = 0; index < new_lv->lv_niovecs; index++) - len += new_lv->lv_iovecp[index].i_len; + if (ordered) + goto insert; - new_lv->lv_buf_len = len; - new_lv->lv_buf = kmem_alloc(new_lv->lv_buf_len, - KM_SLEEP|KM_NOFS); - ptr = new_lv->lv_buf; - - for (index = 0; index < new_lv->lv_niovecs; index++) { - struct xfs_log_iovec *vec = &new_lv->lv_iovecp[index]; - - memcpy(ptr, vec->i_addr, vec->i_len); - vec->i_addr = ptr; - ptr += vec->i_len; - } - ASSERT(ptr == new_lv->lv_buf + new_lv->lv_buf_len); - -next: - if (!ret_lv) - ret_lv = new_lv; - else - lv->lv_next = new_lv; - lv = new_lv; - } - - return ret_lv; -} - -/* - * Prepare the log item for insertion into the CIL. Calculate the difference in - * log space and vectors it will consume, and if it is a new item pin it as - * well. - */ -STATIC void -xfs_cil_prepare_item( - struct xlog *log, - struct xfs_log_vec *lv, - int *len, - int *diff_iovecs) -{ - struct xfs_log_vec *old = lv->lv_item->li_lv; + /* + * set the item up as though it is a new insertion so + * that the space reservation accounting is correct. + */ + *diff_iovecs -= lv->lv_niovecs; + *diff_len -= lv->lv_buf_len; - if (old) { - /* existing lv on log item, space used is a delta */ - ASSERT((old->lv_buf && old->lv_buf_len && old->lv_niovecs) || - old->lv_buf_len == XFS_LOG_VEC_ORDERED); + /* Ensure the lv is set up according to ->iop_size */ + lv->lv_niovecs = niovecs; + lv->lv_buf = (char *)lv + buf_size - nbytes; - /* - * If the new item is ordered, keep the old one that is already - * tracking dirty or ordered regions - */ - if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) { - ASSERT(!lv->lv_buf); - kmem_free(lv); - return; + lv->lv_buf_len = xlog_cil_lv_item_format(lip, lv); + goto insert; } - *len += lv->lv_buf_len - old->lv_buf_len; - *diff_iovecs += lv->lv_niovecs - old->lv_niovecs; - kmem_free(old->lv_buf); - kmem_free(old); - } else { - /* new lv, must pin the log item */ - ASSERT(!lv->lv_item->li_lv); - - if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) { - *len += lv->lv_buf_len; - *diff_iovecs += lv->lv_niovecs; + /* allocate new data chunk */ + lv = kmem_zalloc(buf_size, KM_SLEEP|KM_NOFS); + lv->lv_item = lip; + lv->lv_size = buf_size; + lv->lv_niovecs = niovecs; + if (ordered) { + /* track as an ordered logvec */ + ASSERT(lip->li_lv == NULL); + lv->lv_buf_len = XFS_LOG_VEC_ORDERED; + goto insert; } - IOP_PIN(lv->lv_item); - } + /* The allocated iovec region lies beyond the log vector. */ + lv->lv_iovecp = (struct xfs_log_iovec *)&lv[1]; - /* attach new log vector to log item */ - lv->lv_item->li_lv = lv; + /* The allocated data region lies beyond the iovec region */ + lv->lv_buf = (char *)lv + buf_size - nbytes; - /* - * If this is the first time the item is being committed to the - * CIL, store the sequence number on the log item so we can - * tell in future commits whether this is the first checkpoint - * the item is being committed into. - */ - if (!lv->lv_item->li_seq) - lv->lv_item->li_seq = log->l_cilp->xc_ctx->sequence; + lv->lv_buf_len = xlog_cil_lv_item_format(lip, lv); +insert: + ASSERT(lv->lv_buf_len <= nbytes); + xfs_cil_prepare_item(log, lv, old_lv, diff_len, diff_iovecs); + } } /* @@ -261,53 +296,47 @@ xfs_cil_prepare_item( static void xlog_cil_insert_items( struct xlog *log, - struct xfs_log_vec *log_vector, - struct xlog_ticket *ticket) + struct xfs_trans *tp) { struct xfs_cil *cil = log->l_cilp; struct xfs_cil_ctx *ctx = cil->xc_ctx; - struct xfs_log_vec *lv; + struct xfs_log_item_desc *lidp; int len = 0; int diff_iovecs = 0; int iclog_space; - ASSERT(log_vector); + ASSERT(tp); /* - * Do all the accounting aggregation and switching of log vectors - * around in a separate loop to the insertion of items into the CIL. - * Then we can do a separate loop to update the CIL within a single - * lock/unlock pair. This reduces the number of round trips on the CIL - * lock from O(nr_logvectors) to O(1) and greatly reduces the overall - * hold time for the transaction commit. - * - * If this is the first time the item is being placed into the CIL in - * this context, pin it so it can't be written to disk until the CIL is - * flushed to the iclog and the iclog written to disk. - * * We can do this safely because the context can't checkpoint until we * are done so it doesn't matter exactly how we update the CIL. */ + xlog_cil_insert_format_items(log, tp, &len, &diff_iovecs); + + /* + * Now (re-)position everything modified at the tail of the CIL. + * We do this here so we only need to take the CIL lock once during + * the transaction commit. + */ spin_lock(&cil->xc_cil_lock); - for (lv = log_vector; lv; ) { - struct xfs_log_vec *next = lv->lv_next; + list_for_each_entry(lidp, &tp->t_items, lid_trans) { + struct xfs_log_item *lip = lidp->lid_item; - ASSERT(lv->lv_item->li_lv || list_empty(&lv->lv_item->li_cil)); - lv->lv_next = NULL; + /* Skip items which aren't dirty in this transaction. */ + if (!(lidp->lid_flags & XFS_LID_DIRTY)) + continue; - /* - * xfs_cil_prepare_item() may free the lv, so move the item on - * the CIL first. - */ - list_move_tail(&lv->lv_item->li_cil, &cil->xc_cil); - xfs_cil_prepare_item(log, lv, &len, &diff_iovecs); - lv = next; + list_move_tail(&lip->li_cil, &cil->xc_cil); } /* account for space used by new iovec headers */ len += diff_iovecs * sizeof(xlog_op_header_t); 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); + /* * Now transfer enough transaction reservation to the context ticket * for the checkpoint. The context ticket is special - the unit @@ -316,10 +345,8 @@ xlog_cil_insert_items( * during the transaction commit. */ if (ctx->ticket->t_curr_res == 0) { - /* first commit in checkpoint, steal the header reservation */ - ASSERT(ticket->t_curr_res >= ctx->ticket->t_unit_res + len); ctx->ticket->t_curr_res = ctx->ticket->t_unit_res; - ticket->t_curr_res -= ctx->ticket->t_unit_res; + tp->t_ticket->t_curr_res -= ctx->ticket->t_unit_res; } /* do we need space for more log record headers? */ @@ -333,10 +360,10 @@ xlog_cil_insert_items( hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header); ctx->ticket->t_unit_res += hdrs; ctx->ticket->t_curr_res += hdrs; - ticket->t_curr_res -= hdrs; - ASSERT(ticket->t_curr_res >= len); + tp->t_ticket->t_curr_res -= hdrs; + ASSERT(tp->t_ticket->t_curr_res >= len); } - ticket->t_curr_res -= len; + tp->t_ticket->t_curr_res -= len; ctx->space_used += len; spin_unlock(&cil->xc_cil_lock); @@ -350,7 +377,6 @@ xlog_cil_free_logvec( for (lv = log_vector; lv; ) { struct xfs_log_vec *next = lv->lv_next; - kmem_free(lv->lv_buf); kmem_free(lv); lv = next; } @@ -376,9 +402,9 @@ xlog_cil_committed( xfs_extent_busy_clear(mp, &ctx->busy_extents, (mp->m_flags & XFS_MOUNT_DISCARD) && !abort); - spin_lock(&ctx->cil->xc_cil_lock); + spin_lock(&ctx->cil->xc_push_lock); list_del(&ctx->committing); - spin_unlock(&ctx->cil->xc_cil_lock); + spin_unlock(&ctx->cil->xc_push_lock); xlog_cil_free_logvec(ctx->lv_chain); @@ -433,7 +459,7 @@ xlog_cil_push( down_write(&cil->xc_ctx_lock); ctx = cil->xc_ctx; - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); push_seq = cil->xc_push_seq; ASSERT(push_seq <= ctx->sequence); @@ -444,10 +470,10 @@ xlog_cil_push( */ if (list_empty(&cil->xc_cil)) { cil->xc_push_seq = 0; - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); goto out_skip; } - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); /* check for a previously pushed seqeunce */ @@ -515,9 +541,9 @@ xlog_cil_push( * that higher sequences will wait for us to write out a commit record * before they do. */ - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); list_add(&ctx->committing, &cil->xc_committing); - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); up_write(&cil->xc_ctx_lock); /* @@ -552,7 +578,7 @@ xlog_cil_push( * order the commit records so replay will get them in the right order. */ restart: - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); list_for_each_entry(new_ctx, &cil->xc_committing, committing) { /* * Higher sequences will wait for this one so skip them. @@ -565,11 +591,11 @@ restart: * It is still being pushed! Wait for the push to * complete, then start again from the beginning. */ - xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock); + xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); goto restart; } } - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); /* xfs_log_done always frees the ticket on error. */ commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0); @@ -588,10 +614,10 @@ restart: * callbacks to the iclog we can assign the commit LSN to the context * and wake up anyone who is waiting for the commit to complete. */ - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); ctx->commit_lsn = commit_lsn; wake_up_all(&cil->xc_commit_wait); - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); /* release the hounds! */ return xfs_log_release_iclog(log->l_mp, commit_iclog); @@ -644,12 +670,12 @@ xlog_cil_push_background( if (cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) return; - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); if (cil->xc_push_seq < cil->xc_current_sequence) { cil->xc_push_seq = cil->xc_current_sequence; queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); } - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); } @@ -672,19 +698,33 @@ xlog_cil_push_foreground( * If the CIL is empty or we've already pushed the sequence then * there's no work we need to do. */ - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); if (list_empty(&cil->xc_cil) || push_seq <= cil->xc_push_seq) { - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); return; } cil->xc_push_seq = push_seq; - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); /* do the push now */ xlog_cil_push(log); } +bool +xlog_cil_empty( + struct xlog *log) +{ + struct xfs_cil *cil = log->l_cilp; + bool empty = false; + + spin_lock(&cil->xc_push_lock); + if (list_empty(&cil->xc_cil)) + empty = true; + spin_unlock(&cil->xc_push_lock); + return empty; +} + /* * Commit a transaction with the given vector to the Committed Item List. * @@ -706,43 +746,25 @@ xfs_log_commit_cil( int flags) { struct xlog *log = mp->m_log; + struct xfs_cil *cil = log->l_cilp; int log_flags = 0; - struct xfs_log_vec *log_vector; if (flags & XFS_TRANS_RELEASE_LOG_RES) log_flags = XFS_LOG_REL_PERM_RESERV; - /* - * Do all the hard work of formatting items (including memory - * allocation) outside the CIL context lock. This prevents stalling CIL - * pushes when we are low on memory and a transaction commit spends a - * lot of time in memory reclaim. - */ - log_vector = xlog_cil_prepare_log_vecs(tp); - if (!log_vector) - return ENOMEM; - /* lock out background commit */ - down_read(&log->l_cilp->xc_ctx_lock); - if (commit_lsn) - *commit_lsn = log->l_cilp->xc_ctx->sequence; + down_read(&cil->xc_ctx_lock); - /* xlog_cil_insert_items() destroys log_vector list */ - xlog_cil_insert_items(log, log_vector, tp->t_ticket); + xlog_cil_insert_items(log, tp); /* check we didn't blow the reservation */ if (tp->t_ticket->t_curr_res < 0) - xlog_print_tic_res(log->l_mp, tp->t_ticket); + xlog_print_tic_res(mp, tp->t_ticket); - /* attach the transaction to the CIL if it has any busy extents */ - if (!list_empty(&tp->t_busy)) { - spin_lock(&log->l_cilp->xc_cil_lock); - list_splice_init(&tp->t_busy, - &log->l_cilp->xc_ctx->busy_extents); - spin_unlock(&log->l_cilp->xc_cil_lock); - } + tp->t_commit_lsn = cil->xc_ctx->sequence; + if (commit_lsn) + *commit_lsn = tp->t_commit_lsn; - tp->t_commit_lsn = *commit_lsn; xfs_log_done(mp, tp->t_ticket, NULL, log_flags); xfs_trans_unreserve_and_mod_sb(tp); @@ -757,11 +779,11 @@ xfs_log_commit_cil( * the log items. This affects (at least) processing of stale buffers, * inodes and EFIs. */ - xfs_trans_free_items(tp, *commit_lsn, 0); + xfs_trans_free_items(tp, tp->t_commit_lsn, 0); xlog_cil_push_background(log); - up_read(&log->l_cilp->xc_ctx_lock); + up_read(&cil->xc_ctx_lock); return 0; } @@ -800,7 +822,7 @@ xlog_cil_force_lsn( * on commits for those as well. */ restart: - spin_lock(&cil->xc_cil_lock); + spin_lock(&cil->xc_push_lock); list_for_each_entry(ctx, &cil->xc_committing, committing) { if (ctx->sequence > sequence) continue; @@ -809,7 +831,7 @@ restart: * It is still being pushed! Wait for the push to * complete, then start again from the beginning. */ - xlog_wait(&cil->xc_commit_wait, &cil->xc_cil_lock); + xlog_wait(&cil->xc_commit_wait, &cil->xc_push_lock); goto restart; } if (ctx->sequence != sequence) @@ -817,7 +839,7 @@ restart: /* found it! */ commit_lsn = ctx->commit_lsn; } - spin_unlock(&cil->xc_cil_lock); + spin_unlock(&cil->xc_push_lock); return commit_lsn; } @@ -875,6 +897,7 @@ xlog_cil_init( INIT_LIST_HEAD(&cil->xc_cil); INIT_LIST_HEAD(&cil->xc_committing); spin_lock_init(&cil->xc_cil_lock); + spin_lock_init(&cil->xc_push_lock); init_rwsem(&cil->xc_ctx_lock); init_waitqueue_head(&cil->xc_commit_wait);