diff options
Diffstat (limited to 'fs/xfs/xfs_log_cil.c')
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 117 |
1 files changed, 94 insertions, 23 deletions
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index cdebd832c3d..b3425b34e3d 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -97,7 +97,7 @@ xfs_cil_prepare_item( { /* Account for the new LV being passed in */ if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) { - *diff_len += lv->lv_buf_len; + *diff_len += lv->lv_bytes; *diff_iovecs += lv->lv_niovecs; } @@ -111,7 +111,7 @@ xfs_cil_prepare_item( else if (old_lv != lv) { ASSERT(lv->lv_buf_len != XFS_LOG_VEC_ORDERED); - *diff_len -= old_lv->lv_buf_len; + *diff_len -= old_lv->lv_bytes; *diff_iovecs -= old_lv->lv_niovecs; kmem_free(old_lv); } @@ -205,16 +205,25 @@ xlog_cil_insert_format_items( /* * 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. + * 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. */ nbytes += niovecs * sizeof(uint64_t); + nbytes = round_up(nbytes, sizeof(uint64_t)); /* grab the old item if it exists for reservation accounting */ old_lv = lip->li_lv; - /* calc buffer size */ - buf_size = sizeof(struct xfs_log_vec) + nbytes + - niovecs * sizeof(struct xfs_log_iovec); + /* + * The data buffer needs to start 64-bit aligned, so round up + * that space to ensure we can align it appropriately and not + * overrun the buffer. + */ + buf_size = nbytes + + round_up((sizeof(struct xfs_log_vec) + + niovecs * sizeof(struct xfs_log_iovec)), + sizeof(uint64_t)); /* compare to existing item size */ if (lip->li_lv && buf_size <= lip->li_lv->lv_size) { @@ -230,7 +239,7 @@ xlog_cil_insert_format_items( * that the space reservation accounting is correct. */ *diff_iovecs -= lv->lv_niovecs; - *diff_len -= lv->lv_buf_len; + *diff_len -= lv->lv_bytes; } else { /* allocate new data chunk */ lv = kmem_zalloc(buf_size, KM_SLEEP|KM_NOFS); @@ -250,7 +259,10 @@ xlog_cil_insert_format_items( /* The allocated data region lies beyond the iovec region */ lv->lv_buf_len = 0; + lv->lv_bytes = 0; lv->lv_buf = (char *)lv + buf_size - nbytes; + ASSERT(IS_ALIGNED((unsigned long)lv->lv_buf, sizeof(uint64_t))); + lip->li_ops->iop_format(lip, lv); insert: ASSERT(lv->lv_buf_len <= nbytes); @@ -374,7 +386,15 @@ xlog_cil_committed( xfs_extent_busy_clear(mp, &ctx->busy_extents, (mp->m_flags & XFS_MOUNT_DISCARD) && !abort); + /* + * If we are aborting the commit, wake up anyone waiting on the + * committing list. If we don't, then a shutdown we can leave processes + * waiting in xlog_cil_force_lsn() waiting on a sequence commit that + * will never happen because we aborted it. + */ spin_lock(&ctx->cil->xc_push_lock); + if (abort) + wake_up_all(&ctx->cil->xc_commit_wait); list_del(&ctx->committing); spin_unlock(&ctx->cil->xc_push_lock); @@ -488,13 +508,6 @@ xlog_cil_push( cil->xc_ctx = new_ctx; /* - * mirror the new sequence into the cil structure so that we can do - * unlocked checks against the current sequence in log forces without - * risking deferencing a freed context pointer. - */ - cil->xc_current_sequence = new_ctx->sequence; - - /* * The switch is now done, so we can drop the context lock and move out * of a shared context. We can't just go straight to the commit record, * though - we need to synchronise with previous and future commits so @@ -512,8 +525,15 @@ xlog_cil_push( * Hence we need to add this context to the committing context list so * that higher sequences will wait for us to write out a commit record * before they do. + * + * xfs_log_force_lsn requires us to mirror the new sequence into the cil + * structure atomically with the addition of this sequence to the + * committing list. This also ensures that we can do unlocked checks + * against the current sequence in log forces without risking + * deferencing a freed context pointer. */ spin_lock(&cil->xc_push_lock); + cil->xc_current_sequence = new_ctx->sequence; list_add(&ctx->committing, &cil->xc_committing); spin_unlock(&cil->xc_push_lock); up_write(&cil->xc_ctx_lock); @@ -553,8 +573,18 @@ restart: spin_lock(&cil->xc_push_lock); list_for_each_entry(new_ctx, &cil->xc_committing, committing) { /* + * Avoid getting stuck in this loop because we were woken by the + * shutdown, but then went back to sleep once already in the + * shutdown state. + */ + if (XLOG_FORCED_SHUTDOWN(log)) { + spin_unlock(&cil->xc_push_lock); + goto out_abort_free_ticket; + } + + /* * Higher sequences will wait for this one so skip them. - * Don't wait for own own sequence, either. + * Don't wait for our own sequence, either. */ if (new_ctx->sequence >= ctx->sequence) continue; @@ -651,8 +681,14 @@ xlog_cil_push_background( } +/* + * xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence + * number that is passed. When it returns, the work will be queued for + * @push_seq, but it won't be completed. The caller is expected to do any + * waiting for push_seq to complete if it is required. + */ static void -xlog_cil_push_foreground( +xlog_cil_push_now( struct xlog *log, xfs_lsn_t push_seq) { @@ -677,10 +713,8 @@ xlog_cil_push_foreground( } cil->xc_push_seq = push_seq; + queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work); spin_unlock(&cil->xc_push_lock); - - /* do the push now */ - xlog_cil_push(log); } bool @@ -710,7 +744,7 @@ xlog_cil_empty( * background commit, returns without it held once background commits are * allowed again. */ -int +void xfs_log_commit_cil( struct xfs_mount *mp, struct xfs_trans *tp, @@ -756,7 +790,6 @@ xfs_log_commit_cil( xlog_cil_push_background(log); up_read(&cil->xc_ctx_lock); - return 0; } /* @@ -785,7 +818,8 @@ xlog_cil_force_lsn( * xlog_cil_push() handles racing pushes for the same sequence, * so no need to deal with it here. */ - xlog_cil_push_foreground(log, sequence); +restart: + xlog_cil_push_now(log, sequence); /* * See if we can find a previous sequence still committing. @@ -793,9 +827,15 @@ xlog_cil_force_lsn( * before allowing the force of push_seq to go ahead. Hence block * on commits for those as well. */ -restart: spin_lock(&cil->xc_push_lock); list_for_each_entry(ctx, &cil->xc_committing, committing) { + /* + * Avoid getting stuck in this loop because we were woken by the + * shutdown, but then went back to sleep once already in the + * shutdown state. + */ + if (XLOG_FORCED_SHUTDOWN(log)) + goto out_shutdown; if (ctx->sequence > sequence) continue; if (!ctx->commit_lsn) { @@ -811,8 +851,39 @@ restart: /* found it! */ commit_lsn = ctx->commit_lsn; } + + /* + * The call to xlog_cil_push_now() executes the push in the background. + * Hence by the time we have got here it our sequence may not have been + * pushed yet. This is true if the current sequence still matches the + * push sequence after the above wait loop and the CIL still contains + * dirty objects. + * + * When the push occurs, it will empty the CIL and atomically increment + * the currect sequence past the push sequence and move it into the + * committing list. Of course, if the CIL is clean at the time of the + * push, it won't have pushed the CIL at all, so in that case we should + * try the push for this sequence again from the start just in case. + */ + if (sequence == cil->xc_current_sequence && + !list_empty(&cil->xc_cil)) { + spin_unlock(&cil->xc_push_lock); + goto restart; + } + spin_unlock(&cil->xc_push_lock); return commit_lsn; + + /* + * We detected a shutdown in progress. We need to trigger the log force + * to pass through it's iclog state machine error handling, even though + * we are already in a shutdown state. Hence we can't return + * NULLCOMMITLSN here as that has special meaning to log forces (i.e. + * LSN is already stable), so we return a zero LSN instead. + */ +out_shutdown: + spin_unlock(&cil->xc_push_lock); + return 0; } /* |