diff options
Diffstat (limited to 'fs/netfs')
| -rw-r--r-- | fs/netfs/Makefile | 5 | ||||
| -rw-r--r-- | fs/netfs/buffered_read.c | 297 | ||||
| -rw-r--r-- | fs/netfs/direct_read.c | 84 | ||||
| -rw-r--r-- | fs/netfs/direct_write.c | 10 | ||||
| -rw-r--r-- | fs/netfs/internal.h | 45 | ||||
| -rw-r--r-- | fs/netfs/main.c | 6 | ||||
| -rw-r--r-- | fs/netfs/misc.c | 164 | ||||
| -rw-r--r-- | fs/netfs/objects.c | 21 | ||||
| -rw-r--r-- | fs/netfs/read_collect.c | 764 | ||||
| -rw-r--r-- | fs/netfs/read_pgpriv2.c | 208 | ||||
| -rw-r--r-- | fs/netfs/read_retry.c | 234 | ||||
| -rw-r--r-- | fs/netfs/read_single.c | 195 | ||||
| -rw-r--r-- | fs/netfs/rolling_buffer.c | 222 | ||||
| -rw-r--r-- | fs/netfs/stats.c | 13 | ||||
| -rw-r--r-- | fs/netfs/write_collect.c | 284 | ||||
| -rw-r--r-- | fs/netfs/write_issue.c | 242 | ||||
| -rw-r--r-- | fs/netfs/write_retry.c | 234 |
17 files changed, 1914 insertions, 1114 deletions
diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile index d08b0bfb6756..b43188d64bd8 100644 --- a/fs/netfs/Makefile +++ b/fs/netfs/Makefile @@ -13,8 +13,11 @@ netfs-y := \ read_collect.o \ read_pgpriv2.o \ read_retry.o \ + read_single.o \ + rolling_buffer.o \ write_collect.o \ - write_issue.o + write_issue.o \ + write_retry.o netfs-$(CONFIG_NETFS_STATS) += stats.o diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c index 4dc9b8286355..0d1b6d35ff3b 100644 --- a/fs/netfs/buffered_read.c +++ b/fs/netfs/buffered_read.c @@ -64,37 +64,6 @@ static int netfs_begin_cache_read(struct netfs_io_request *rreq, struct netfs_in } /* - * Decant the list of folios to read into a rolling buffer. - */ -static size_t netfs_load_buffer_from_ra(struct netfs_io_request *rreq, - struct folio_queue *folioq, - struct folio_batch *put_batch) -{ - unsigned int order, nr; - size_t size = 0; - - nr = __readahead_batch(rreq->ractl, (struct page **)folioq->vec.folios, - ARRAY_SIZE(folioq->vec.folios)); - folioq->vec.nr = nr; - for (int i = 0; i < nr; i++) { - struct folio *folio = folioq_folio(folioq, i); - - trace_netfs_folio(folio, netfs_folio_trace_read); - order = folio_order(folio); - folioq->orders[i] = order; - size += PAGE_SIZE << order; - - if (!folio_batch_add(put_batch, folio)) - folio_batch_release(put_batch); - } - - for (int i = nr; i < folioq_nr_slots(folioq); i++) - folioq_clear(folioq, i); - - return size; -} - -/* * netfs_prepare_read_iterator - Prepare the subreq iterator for I/O * @subreq: The subrequest to be set up * @@ -128,19 +97,12 @@ static ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq) folio_batch_init(&put_batch); while (rreq->submitted < subreq->start + rsize) { - struct folio_queue *tail = rreq->buffer_tail, *new; - size_t added; - - new = kmalloc(sizeof(*new), GFP_NOFS); - if (!new) - return -ENOMEM; - netfs_stat(&netfs_n_folioq); - folioq_init(new); - new->prev = tail; - tail->next = new; - rreq->buffer_tail = new; - added = netfs_load_buffer_from_ra(rreq, new, &put_batch); - rreq->iter.count += added; + ssize_t added; + + added = rolling_buffer_load_from_ra(&rreq->buffer, rreq->ractl, + &put_batch); + if (added < 0) + return added; rreq->submitted += added; } folio_batch_release(&put_batch); @@ -148,7 +110,7 @@ static ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq) subreq->len = rsize; if (unlikely(rreq->io_streams[0].sreq_max_segs)) { - size_t limit = netfs_limit_iter(&rreq->iter, 0, rsize, + size_t limit = netfs_limit_iter(&rreq->buffer.iter, 0, rsize, rreq->io_streams[0].sreq_max_segs); if (limit < rsize) { @@ -157,20 +119,10 @@ static ssize_t netfs_prepare_read_iterator(struct netfs_io_subrequest *subreq) } } - subreq->io_iter = rreq->iter; - - if (iov_iter_is_folioq(&subreq->io_iter)) { - if (subreq->io_iter.folioq_slot >= folioq_nr_slots(subreq->io_iter.folioq)) { - subreq->io_iter.folioq = subreq->io_iter.folioq->next; - subreq->io_iter.folioq_slot = 0; - } - subreq->curr_folioq = (struct folio_queue *)subreq->io_iter.folioq; - subreq->curr_folioq_slot = subreq->io_iter.folioq_slot; - subreq->curr_folio_order = subreq->curr_folioq->orders[subreq->curr_folioq_slot]; - } + subreq->io_iter = rreq->buffer.iter; iov_iter_truncate(&subreq->io_iter, subreq->len); - iov_iter_advance(&rreq->iter, subreq->len); + rolling_buffer_advance(&rreq->buffer, subreq->len); return subreq->len; } @@ -179,25 +131,14 @@ static enum netfs_io_source netfs_cache_prepare_read(struct netfs_io_request *rr loff_t i_size) { struct netfs_cache_resources *cres = &rreq->cache_resources; + enum netfs_io_source source; if (!cres->ops) return NETFS_DOWNLOAD_FROM_SERVER; - return cres->ops->prepare_read(subreq, i_size); -} - -static void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, - bool was_async) -{ - struct netfs_io_subrequest *subreq = priv; - - if (transferred_or_error < 0) { - netfs_read_subreq_terminated(subreq, transferred_or_error, was_async); - return; - } + source = cres->ops->prepare_read(subreq, i_size); + trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); + return source; - if (transferred_or_error > 0) - subreq->transferred += transferred_or_error; - netfs_read_subreq_terminated(subreq, 0, was_async); } /* @@ -214,6 +155,57 @@ static void netfs_read_cache_to_pagecache(struct netfs_io_request *rreq, netfs_cache_read_terminated, subreq); } +static void netfs_queue_read(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq, + bool last_subreq) +{ + struct netfs_io_stream *stream = &rreq->io_streams[0]; + + __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); + + /* We add to the end of the list whilst the collector may be walking + * the list. The collector only goes nextwards and uses the lock to + * remove entries off of the front. + */ + spin_lock(&rreq->lock); + list_add_tail(&subreq->rreq_link, &stream->subrequests); + if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { + stream->front = subreq; + if (!stream->active) { + stream->collected_to = stream->front->start; + /* Store list pointers before active flag */ + smp_store_release(&stream->active, true); + } + } + + if (last_subreq) { + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags); + } + + spin_unlock(&rreq->lock); +} + +static void netfs_issue_read(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq) +{ + switch (subreq->source) { + case NETFS_DOWNLOAD_FROM_SERVER: + rreq->netfs_ops->issue_read(subreq); + break; + case NETFS_READ_FROM_CACHE: + netfs_read_cache_to_pagecache(rreq, subreq); + break; + default: + __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); + subreq->error = 0; + iov_iter_zero(subreq->len, &subreq->io_iter); + subreq->transferred = subreq->len; + netfs_read_subreq_terminated(subreq); + break; + } +} + /* * Perform a read to the pagecache from a series of sources of different types, * slicing up the region to be read according to available cache blocks and @@ -226,11 +218,9 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq) ssize_t size = rreq->len; int ret = 0; - atomic_inc(&rreq->nr_outstanding); - do { struct netfs_io_subrequest *subreq; - enum netfs_io_source source = NETFS_DOWNLOAD_FROM_SERVER; + enum netfs_io_source source = NETFS_SOURCE_UNKNOWN; ssize_t slice; subreq = netfs_alloc_subrequest(rreq); @@ -242,20 +232,14 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq) subreq->start = start; subreq->len = size; - atomic_inc(&rreq->nr_outstanding); - spin_lock_bh(&rreq->lock); - list_add_tail(&subreq->rreq_link, &rreq->subrequests); - subreq->prev_donated = rreq->prev_donated; - rreq->prev_donated = 0; - trace_netfs_sreq(subreq, netfs_sreq_trace_added); - spin_unlock_bh(&rreq->lock); - source = netfs_cache_prepare_read(rreq, subreq, rreq->i_size); subreq->source = source; if (source == NETFS_DOWNLOAD_FROM_SERVER) { unsigned long long zp = umin(ictx->zero_point, rreq->i_size); size_t len = subreq->len; + if (unlikely(rreq->origin == NETFS_READ_SINGLE)) + zp = rreq->i_size; if (subreq->start >= zp) { subreq->source = source = NETFS_FILL_WITH_ZEROES; goto fill_with_zeroes; @@ -275,17 +259,18 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq) netfs_stat(&netfs_n_rh_download); if (rreq->netfs_ops->prepare_read) { ret = rreq->netfs_ops->prepare_read(subreq); - if (ret < 0) - goto prep_failed; + if (ret < 0) { + subreq->error = ret; + /* Not queued - release both refs. */ + netfs_put_subrequest(subreq, false, + netfs_sreq_trace_put_cancel); + netfs_put_subrequest(subreq, false, + netfs_sreq_trace_put_cancel); + break; + } trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); } - - slice = netfs_prepare_read_iterator(subreq); - if (slice < 0) - goto prep_iter_failed; - - rreq->netfs_ops->issue_read(subreq); - goto done; + goto issue; } fill_with_zeroes: @@ -293,94 +278,47 @@ static void netfs_read_to_pagecache(struct netfs_io_request *rreq) subreq->source = NETFS_FILL_WITH_ZEROES; trace_netfs_sreq(subreq, netfs_sreq_trace_submit); netfs_stat(&netfs_n_rh_zero); - slice = netfs_prepare_read_iterator(subreq); - if (slice < 0) - goto prep_iter_failed; - __set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags); - netfs_read_subreq_terminated(subreq, 0, false); - goto done; + goto issue; } if (source == NETFS_READ_FROM_CACHE) { trace_netfs_sreq(subreq, netfs_sreq_trace_submit); - slice = netfs_prepare_read_iterator(subreq); - if (slice < 0) - goto prep_iter_failed; - netfs_read_cache_to_pagecache(rreq, subreq); - goto done; + goto issue; } pr_err("Unexpected read source %u\n", source); WARN_ON_ONCE(1); break; - prep_iter_failed: - ret = slice; - prep_failed: - subreq->error = ret; - atomic_dec(&rreq->nr_outstanding); - netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel); - break; - - done: + issue: + slice = netfs_prepare_read_iterator(subreq); + if (slice < 0) { + ret = slice; + subreq->error = ret; + trace_netfs_sreq(subreq, netfs_sreq_trace_cancel); + /* Not queued - release both refs. */ + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel); + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel); + break; + } size -= slice; start += slice; + + netfs_queue_read(rreq, subreq, size <= 0); + netfs_issue_read(rreq, subreq); cond_resched(); } while (size > 0); - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_terminated(rreq, false); + if (unlikely(size > 0)) { + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags); + netfs_wake_read_collector(rreq); + } /* Defer error return as we may need to wait for outstanding I/O. */ cmpxchg(&rreq->error, 0, ret); } -/* - * Wait for the read operation to complete, successfully or otherwise. - */ -static int netfs_wait_for_read(struct netfs_io_request *rreq) -{ - int ret; - - trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip); - wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS, TASK_UNINTERRUPTIBLE); - ret = rreq->error; - if (ret == 0 && rreq->submitted < rreq->len) { - trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); - ret = -EIO; - } - - return ret; -} - -/* - * Set up the initial folioq of buffer folios in the rolling buffer and set the - * iterator to refer to it. - */ -static int netfs_prime_buffer(struct netfs_io_request *rreq) -{ - struct folio_queue *folioq; - struct folio_batch put_batch; - size_t added; - - folioq = kmalloc(sizeof(*folioq), GFP_KERNEL); - if (!folioq) - return -ENOMEM; - netfs_stat(&netfs_n_folioq); - folioq_init(folioq); - rreq->buffer = folioq; - rreq->buffer_tail = folioq; - rreq->submitted = rreq->start; - iov_iter_folio_queue(&rreq->iter, ITER_DEST, folioq, 0, 0, 0); - - folio_batch_init(&put_batch); - added = netfs_load_buffer_from_ra(rreq, folioq, &put_batch); - folio_batch_release(&put_batch); - rreq->iter.count += added; - rreq->submitted += added; - return 0; -} - /** * netfs_readahead - Helper to manage a read request * @ractl: The description of the readahead request @@ -409,6 +347,8 @@ void netfs_readahead(struct readahead_control *ractl) if (IS_ERR(rreq)) return; + __set_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags); + ret = netfs_begin_cache_read(rreq, ictx); if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS) goto cleanup_free; @@ -420,7 +360,8 @@ void netfs_readahead(struct readahead_control *ractl) netfs_rreq_expand(rreq, ractl); rreq->ractl = ractl; - if (netfs_prime_buffer(rreq) < 0) + rreq->submitted = rreq->start; + if (rolling_buffer_init(&rreq->buffer, rreq->debug_id, ITER_DEST) < 0) goto cleanup_free; netfs_read_to_pagecache(rreq); @@ -436,23 +377,18 @@ EXPORT_SYMBOL(netfs_readahead); /* * Create a rolling buffer with a single occupying folio. */ -static int netfs_create_singular_buffer(struct netfs_io_request *rreq, struct folio *folio) +static int netfs_create_singular_buffer(struct netfs_io_request *rreq, struct folio *folio, + unsigned int rollbuf_flags) { - struct folio_queue *folioq; + ssize_t added; - folioq = kmalloc(sizeof(*folioq), GFP_KERNEL); - if (!folioq) + if (rolling_buffer_init(&rreq->buffer, rreq->debug_id, ITER_DEST) < 0) return -ENOMEM; - netfs_stat(&netfs_n_folioq); - folioq_init(folioq); - folioq_append(folioq, folio); - BUG_ON(folioq_folio(folioq, 0) != folio); - BUG_ON(folioq_folio_order(folioq, 0) != folio_order(folio)); - rreq->buffer = folioq; - rreq->buffer_tail = folioq; - rreq->submitted = rreq->start + rreq->len; - iov_iter_folio_queue(&rreq->iter, ITER_DEST, folioq, 0, 0, rreq->len); + added = rolling_buffer_append(&rreq->buffer, folio, rollbuf_flags); + if (added < 0) + return added; + rreq->submitted = rreq->start + added; rreq->ractl = (struct readahead_control *)1UL; return 0; } @@ -520,7 +456,7 @@ static int netfs_read_gaps(struct file *file, struct folio *folio) } if (to < flen) bvec_set_folio(&bvec[i++], folio, flen - to, to); - iov_iter_bvec(&rreq->iter, ITER_DEST, bvec, i, rreq->len); + iov_iter_bvec(&rreq->buffer.iter, ITER_DEST, bvec, i, rreq->len); rreq->submitted = rreq->start + flen; netfs_read_to_pagecache(rreq); @@ -529,7 +465,7 @@ static int netfs_read_gaps(struct file *file, struct folio *folio) folio_put(sink); ret = netfs_wait_for_read(rreq); - if (ret == 0) { + if (ret >= 0) { flush_dcache_folio(folio); folio_mark_uptodate(folio); } @@ -588,7 +524,7 @@ int netfs_read_folio(struct file *file, struct folio *folio) trace_netfs_read(rreq, rreq->start, rreq->len, netfs_read_trace_readpage); /* Set up the output buffer */ - ret = netfs_create_singular_buffer(rreq, folio); + ret = netfs_create_singular_buffer(rreq, folio, 0); if (ret < 0) goto discard; @@ -745,7 +681,7 @@ retry: trace_netfs_read(rreq, pos, len, netfs_read_trace_write_begin); /* Set up the output buffer */ - ret = netfs_create_singular_buffer(rreq, folio); + ret = netfs_create_singular_buffer(rreq, folio, 0); if (ret < 0) goto error_put; @@ -810,15 +746,14 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio, trace_netfs_read(rreq, start, flen, netfs_read_trace_prefetch_for_write); /* Set up the output buffer */ - ret = netfs_create_singular_buffer(rreq, folio); + ret = netfs_create_singular_buffer(rreq, folio, NETFS_ROLLBUF_PAGECACHE_MARK); if (ret < 0) goto error_put; - folioq_mark2(rreq->buffer, 0); netfs_read_to_pagecache(rreq); ret = netfs_wait_for_read(rreq); netfs_put_request(rreq, false, netfs_rreq_trace_put_return); - return ret; + return ret < 0 ? ret : 0; error_put: netfs_put_request(rreq, false, netfs_rreq_trace_put_discard); diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c index b1a66a6e6bc2..5e3f0aeb51f3 100644 --- a/fs/netfs/direct_read.c +++ b/fs/netfs/direct_read.c @@ -25,7 +25,7 @@ static void netfs_prepare_dio_read_iterator(struct netfs_io_subrequest *subreq) subreq->len = rsize; if (unlikely(rreq->io_streams[0].sreq_max_segs)) { - size_t limit = netfs_limit_iter(&rreq->iter, 0, rsize, + size_t limit = netfs_limit_iter(&rreq->buffer.iter, 0, rsize, rreq->io_streams[0].sreq_max_segs); if (limit < rsize) { @@ -36,9 +36,9 @@ static void netfs_prepare_dio_read_iterator(struct netfs_io_subrequest *subreq) trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); - subreq->io_iter = rreq->iter; + subreq->io_iter = rreq->buffer.iter; iov_iter_truncate(&subreq->io_iter, subreq->len); - iov_iter_advance(&rreq->iter, subreq->len); + iov_iter_advance(&rreq->buffer.iter, subreq->len); } /* @@ -47,12 +47,11 @@ static void netfs_prepare_dio_read_iterator(struct netfs_io_subrequest *subreq) */ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) { + struct netfs_io_stream *stream = &rreq->io_streams[0]; unsigned long long start = rreq->start; ssize_t size = rreq->len; int ret = 0; - atomic_set(&rreq->nr_outstanding, 1); - do { struct netfs_io_subrequest *subreq; ssize_t slice; @@ -67,19 +66,25 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) subreq->start = start; subreq->len = size; - atomic_inc(&rreq->nr_outstanding); - spin_lock_bh(&rreq->lock); - list_add_tail(&subreq->rreq_link, &rreq->subrequests); - subreq->prev_donated = rreq->prev_donated; - rreq->prev_donated = 0; + __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); + + spin_lock(&rreq->lock); + list_add_tail(&subreq->rreq_link, &stream->subrequests); + if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { + stream->front = subreq; + if (!stream->active) { + stream->collected_to = stream->front->start; + /* Store list pointers before active flag */ + smp_store_release(&stream->active, true); + } + } trace_netfs_sreq(subreq, netfs_sreq_trace_added); - spin_unlock_bh(&rreq->lock); + spin_unlock(&rreq->lock); netfs_stat(&netfs_n_rh_download); if (rreq->netfs_ops->prepare_read) { ret = rreq->netfs_ops->prepare_read(subreq); if (ret < 0) { - atomic_dec(&rreq->nr_outstanding); netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel); break; } @@ -87,20 +92,32 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) netfs_prepare_dio_read_iterator(subreq); slice = subreq->len; - rreq->netfs_ops->issue_read(subreq); - size -= slice; start += slice; rreq->submitted += slice; + if (size <= 0) { + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags); + } + rreq->netfs_ops->issue_read(subreq); + + if (test_bit(NETFS_RREQ_PAUSE, &rreq->flags)) + netfs_wait_for_pause(rreq); + if (test_bit(NETFS_RREQ_FAILED, &rreq->flags)) + break; if (test_bit(NETFS_RREQ_BLOCKED, &rreq->flags) && test_bit(NETFS_RREQ_NONBLOCK, &rreq->flags)) break; cond_resched(); } while (size > 0); - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_terminated(rreq, false); + if (unlikely(size > 0)) { + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags); + netfs_wake_read_collector(rreq); + } + return ret; } @@ -108,9 +125,9 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) * Perform a read to an application buffer, bypassing the pagecache and the * local disk cache. */ -static int netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync) +static ssize_t netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync) { - int ret; + ssize_t ret; _enter("R=%x %llx-%llx", rreq->debug_id, rreq->start, rreq->start + rreq->len - 1); @@ -133,23 +150,12 @@ static int netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync) goto out; } - if (sync) { - trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip); - wait_on_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS, - TASK_UNINTERRUPTIBLE); - - ret = rreq->error; - if (ret == 0 && rreq->submitted < rreq->len && - rreq->origin != NETFS_DIO_READ) { - trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); - ret = -EIO; - } - } else { + if (sync) + ret = netfs_wait_for_read(rreq); + else ret = -EIOCBQUEUED; - } - out: - _leave(" = %d", ret); + _leave(" = %zd", ret); return ret; } @@ -199,15 +205,15 @@ ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *i * the request. */ if (user_backed_iter(iter)) { - ret = netfs_extract_user_iter(iter, rreq->len, &rreq->iter, 0); + ret = netfs_extract_user_iter(iter, rreq->len, &rreq->buffer.iter, 0); if (ret < 0) goto out; - rreq->direct_bv = (struct bio_vec *)rreq->iter.bvec; + rreq->direct_bv = (struct bio_vec *)rreq->buffer.iter.bvec; rreq->direct_bv_count = ret; rreq->direct_bv_unpin = iov_iter_extract_will_pin(iter); - rreq->len = iov_iter_count(&rreq->iter); + rreq->len = iov_iter_count(&rreq->buffer.iter); } else { - rreq->iter = *iter; + rreq->buffer.iter = *iter; rreq->len = orig_count; rreq->direct_bv_unpin = false; iov_iter_advance(iter, orig_count); @@ -215,8 +221,10 @@ ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *i // TODO: Set up bounce buffer if needed - if (!sync) + if (!sync) { rreq->iocb = iocb; + __set_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags); + } ret = netfs_unbuffered_read(rreq, sync); if (ret < 0) diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c index f9421f3e6d37..42ce53cc216e 100644 --- a/fs/netfs/direct_write.c +++ b/fs/netfs/direct_write.c @@ -68,12 +68,12 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * * request. */ if (user_backed_iter(iter)) { - n = netfs_extract_user_iter(iter, len, &wreq->iter, 0); + n = netfs_extract_user_iter(iter, len, &wreq->buffer.iter, 0); if (n < 0) { ret = n; goto out; } - wreq->direct_bv = (struct bio_vec *)wreq->iter.bvec; + wreq->direct_bv = (struct bio_vec *)wreq->buffer.iter.bvec; wreq->direct_bv_count = n; wreq->direct_bv_unpin = iov_iter_extract_will_pin(iter); } else { @@ -82,10 +82,8 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * * (eg. a bio_vec array) will persist till the end of * the op. */ - wreq->iter = *iter; + wreq->buffer.iter = *iter; } - - wreq->io_iter = wreq->iter; } __set_bit(NETFS_RREQ_USE_IO_ITER, &wreq->flags); @@ -97,7 +95,7 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags); if (async) wreq->iocb = iocb; - wreq->len = iov_iter_count(&wreq->io_iter); + wreq->len = iov_iter_count(&wreq->buffer.iter); wreq->cleanup = netfs_cleanup_dio_write; ret = netfs_unbuffered_write(wreq, is_sync_kiocb(iocb), wreq->len); if (ret < 0) { diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index c562aec3b483..1c4f953c3d68 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -23,6 +23,7 @@ /* * buffered_read.c */ +void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, bool was_async); int netfs_prefetch_for_write(struct file *file, struct folio *folio, size_t offset, size_t len); @@ -58,11 +59,8 @@ static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} /* * misc.c */ -struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq); -int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio, - bool needs_put); -struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq); -void netfs_clear_buffer(struct netfs_io_request *rreq); +struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq, + enum netfs_folioq_trace trace); void netfs_reset_iter(struct netfs_io_subrequest *subreq); /* @@ -84,20 +82,27 @@ static inline void netfs_see_request(struct netfs_io_request *rreq, trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what); } +static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq, + enum netfs_sreq_ref_trace what) +{ + trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index, + refcount_read(&subreq->ref), what); +} + /* * read_collect.c */ -void netfs_read_termination_worker(struct work_struct *work); -void netfs_rreq_terminated(struct netfs_io_request *rreq, bool was_async); +void netfs_read_collection_worker(struct work_struct *work); +void netfs_wake_read_collector(struct netfs_io_request *rreq); +void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, bool was_async); +ssize_t netfs_wait_for_read(struct netfs_io_request *rreq); +void netfs_wait_for_pause(struct netfs_io_request *rreq); /* * read_pgpriv2.c */ -void netfs_pgpriv2_mark_copy_to_cache(struct netfs_io_subrequest *subreq, - struct netfs_io_request *rreq, - struct folio_queue *folioq, - int slot); -void netfs_pgpriv2_write_to_the_cache(struct netfs_io_request *rreq); +void netfs_pgpriv2_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio); +void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq); bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq); /* @@ -113,6 +118,7 @@ void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq); extern atomic_t netfs_n_rh_dio_read; extern atomic_t netfs_n_rh_readahead; extern atomic_t netfs_n_rh_read_folio; +extern atomic_t netfs_n_rh_read_single; extern atomic_t netfs_n_rh_rreq; extern atomic_t netfs_n_rh_sreq; extern atomic_t netfs_n_rh_download; @@ -129,6 +135,8 @@ extern atomic_t netfs_n_rh_write_begin; extern atomic_t netfs_n_rh_write_done; extern atomic_t netfs_n_rh_write_failed; extern atomic_t netfs_n_rh_write_zskip; +extern atomic_t netfs_n_rh_retry_read_req; +extern atomic_t netfs_n_rh_retry_read_subreq; extern atomic_t netfs_n_wh_buffered_write; extern atomic_t netfs_n_wh_writethrough; extern atomic_t netfs_n_wh_dio_write; @@ -141,6 +149,8 @@ extern atomic_t netfs_n_wh_upload_failed; extern atomic_t netfs_n_wh_write; extern atomic_t netfs_n_wh_write_done; extern atomic_t netfs_n_wh_write_failed; +extern atomic_t netfs_n_wh_retry_write_req; +extern atomic_t netfs_n_wh_retry_write_subreq; extern atomic_t netfs_n_wb_lock_skip; extern atomic_t netfs_n_wb_lock_wait; extern atomic_t netfs_n_folioq; @@ -181,9 +191,9 @@ void netfs_reissue_write(struct netfs_io_stream *stream, struct iov_iter *source); void netfs_issue_write(struct netfs_io_request *wreq, struct netfs_io_stream *stream); -int netfs_advance_write(struct netfs_io_request *wreq, - struct netfs_io_stream *stream, - loff_t start, size_t len, bool to_eof); +size_t netfs_advance_write(struct netfs_io_request *wreq, + struct netfs_io_stream *stream, + loff_t start, size_t len, bool to_eof); struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len); int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc, struct folio *folio, size_t copied, bool to_page_end, @@ -193,6 +203,11 @@ int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_contr int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len); /* + * write_retry.c + */ +void netfs_retry_writes(struct netfs_io_request *wreq); + +/* * Miscellaneous functions. */ static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx) diff --git a/fs/netfs/main.c b/fs/netfs/main.c index 6c7be1377ee0..4e3e62040831 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -37,9 +37,11 @@ static const char *netfs_origins[nr__netfs_io_origin] = { [NETFS_READAHEAD] = "RA", [NETFS_READPAGE] = "RP", [NETFS_READ_GAPS] = "RG", + [NETFS_READ_SINGLE] = "R1", [NETFS_READ_FOR_WRITE] = "RW", [NETFS_DIO_READ] = "DR", [NETFS_WRITEBACK] = "WB", + [NETFS_WRITEBACK_SINGLE] = "W1", [NETFS_WRITETHROUGH] = "WT", [NETFS_UNBUFFERED_WRITE] = "UW", [NETFS_DIO_WRITE] = "DW", @@ -69,7 +71,7 @@ static int netfs_requests_seq_show(struct seq_file *m, void *v) refcount_read(&rreq->ref), rreq->flags, rreq->error, - atomic_read(&rreq->nr_outstanding), + 0, rreq->start, rreq->submitted, rreq->len); seq_putc(m, '\n'); return 0; @@ -116,7 +118,7 @@ static int __init netfs_init(void) goto error_reqpool; netfs_subrequest_slab = kmem_cache_create("netfs_subrequest", - sizeof(struct netfs_io_subrequest), 0, + sizeof(struct netfs_io_subrequest) + 16, 0, SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); if (!netfs_subrequest_slab) diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index 78fe5796b2b2..7099aa07737a 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -8,113 +8,101 @@ #include <linux/swap.h> #include "internal.h" -/* - * Make sure there's space in the rolling queue. +/** + * netfs_alloc_folioq_buffer - Allocate buffer space into a folio queue + * @mapping: Address space to set on the folio (or NULL). + * @_buffer: Pointer to the folio queue to add to (may point to a NULL; updated). + * @_cur_size: Current size of the buffer (updated). + * @size: Target size of the buffer. + * @gfp: The allocation constraints. */ -struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq) +int netfs_alloc_folioq_buffer(struct address_space *mapping, + struct folio_queue **_buffer, + size_t *_cur_size, ssize_t size, gfp_t gfp) { - struct folio_queue *tail = rreq->buffer_tail, *prev; - unsigned int prev_nr_slots = 0; - - if (WARN_ON_ONCE(!rreq->buffer && tail) || - WARN_ON_ONCE(rreq->buffer && !tail)) - return ERR_PTR(-EIO); - - prev = tail; - if (prev) { - if (!folioq_full(tail)) - return tail; - prev_nr_slots = folioq_nr_slots(tail); - } - - tail = kmalloc(sizeof(*tail), GFP_NOFS); - if (!tail) - return ERR_PTR(-ENOMEM); - netfs_stat(&netfs_n_folioq); - folioq_init(tail); - tail->prev = prev; - if (prev) - /* [!] NOTE: After we set prev->next, the consumer is entirely - * at liberty to delete prev. - */ - WRITE_ONCE(prev->next, tail); - - rreq->buffer_tail = tail; - if (!rreq->buffer) { - rreq->buffer = tail; - iov_iter_folio_queue(&rreq->io_iter, ITER_SOURCE, tail, 0, 0, 0); - } else { - /* Make sure we don't leave the master iterator pointing to a - * block that might get immediately consumed. - */ - if (rreq->io_iter.folioq == prev && - rreq->io_iter.folioq_slot == prev_nr_slots) { - rreq->io_iter.folioq = tail; - rreq->io_iter.folioq_slot = 0; + struct folio_queue *tail = *_buffer, *p; + + size = round_up(size, PAGE_SIZE); + if (*_cur_size >= size) + return 0; + + if (tail) + while (tail->next) + tail = tail->next; + + do { + struct folio *folio; + int order = 0, slot; + + if (!tail || folioq_full(tail)) { + p = netfs_folioq_alloc(0, GFP_NOFS, netfs_trace_folioq_alloc_buffer); + if (!p) + return -ENOMEM; + if (tail) { + tail->next = p; + p->prev = tail; + } else { + *_buffer = p; + } + tail = p; } - } - rreq->buffer_tail_slot = 0; - return tail; -} -/* - * Append a folio to the rolling queue. - */ -int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio, - bool needs_put) -{ - struct folio_queue *tail; - unsigned int slot, order = folio_order(folio); + if (size - *_cur_size > PAGE_SIZE) + order = umin(ilog2(size - *_cur_size) - PAGE_SHIFT, + MAX_PAGECACHE_ORDER); - tail = netfs_buffer_make_space(rreq); - if (IS_ERR(tail)) - return PTR_ERR(tail); + folio = folio_alloc(gfp, order); + if (!folio && order > 0) + folio = folio_alloc(gfp, 0); + if (!folio) + return -ENOMEM; - rreq->io_iter.count += PAGE_SIZE << order; + folio->mapping = mapping; + folio->index = *_cur_size / PAGE_SIZE; + trace_netfs_folio(folio, netfs_folio_trace_alloc_buffer); + slot = folioq_append_mark(tail, folio); + *_cur_size += folioq_folio_size(tail, slot); + } while (*_cur_size < size); - slot = folioq_append(tail, folio); - /* Store the counter after setting the slot. */ - smp_store_release(&rreq->buffer_tail_slot, slot); return 0; } +EXPORT_SYMBOL(netfs_alloc_folioq_buffer); -/* - * Delete the head of a rolling queue. +/** + * netfs_free_folioq_buffer - Free a folio queue. + * @fq: The start of the folio queue to free + * + * Free up a chain of folio_queues and, if marked, the marked folios they point + * to. */ -struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq) +void netfs_free_folioq_buffer(struct folio_queue *fq) { - struct folio_queue *head = wreq->buffer, *next = head->next; - - if (next) - next->prev = NULL; - netfs_stat_d(&netfs_n_folioq); - kfree(head); - wreq->buffer = next; - return next; -} + struct folio_queue *next; + struct folio_batch fbatch; -/* - * Clear out a rolling queue. - */ -void netfs_clear_buffer(struct netfs_io_request *rreq) -{ - struct folio_queue *p; + folio_batch_init(&fbatch); + + for (; fq; fq = next) { + for (int slot = 0; slot < folioq_count(fq); slot++) { + struct folio *folio = folioq_folio(fq, slot); - while ((p = rreq->buffer)) { - rreq->buffer = p->next; - for (int slot = 0; slot < folioq_count(p); slot++) { - struct folio *folio = folioq_folio(p, slot); - if (!folio) + if (!folio || + !folioq_is_marked(fq, slot)) continue; - if (folioq_is_marked(p, slot)) { - trace_netfs_folio(folio, netfs_folio_trace_put); - folio_put(folio); - } + + trace_netfs_folio(folio, netfs_folio_trace_put); + if (folio_batch_add(&fbatch, folio)) + folio_batch_release(&fbatch); } + netfs_stat_d(&netfs_n_folioq); - kfree(p); + next = fq->next; + kfree(fq); } + + folio_batch_release(&fbatch); } +EXPORT_SYMBOL(netfs_free_folioq_buffer); /* * Reset the subrequest iterator to refer just to the region remaining to be diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 31e388ec6e48..dc6b41ef18b0 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -48,17 +48,20 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, spin_lock_init(&rreq->lock); INIT_LIST_HEAD(&rreq->io_streams[0].subrequests); INIT_LIST_HEAD(&rreq->io_streams[1].subrequests); - INIT_LIST_HEAD(&rreq->subrequests); + init_waitqueue_head(&rreq->waitq); refcount_set(&rreq->ref, 1); if (origin == NETFS_READAHEAD || origin == NETFS_READPAGE || origin == NETFS_READ_GAPS || + origin == NETFS_READ_SINGLE || origin == NETFS_READ_FOR_WRITE || - origin == NETFS_DIO_READ) - INIT_WORK(&rreq->work, netfs_read_termination_worker); - else + origin == NETFS_DIO_READ) { + INIT_WORK(&rreq->work, netfs_read_collection_worker); + rreq->io_streams[0].avail = true; + } else { INIT_WORK(&rreq->work, netfs_write_collection_worker); + } __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); if (file && file->f_flags & O_NONBLOCK) @@ -92,14 +95,6 @@ void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async) struct netfs_io_stream *stream; int s; - while (!list_empty(&rreq->subrequests)) { - subreq = list_first_entry(&rreq->subrequests, - struct netfs_io_subrequest, rreq_link); - list_del(&subreq->rreq_link); - netfs_put_subrequest(subreq, was_async, - netfs_sreq_trace_put_clear); - } - for (s = 0; s < ARRAY_SIZE(rreq->io_streams); s++) { stream = &rreq->io_streams[s]; while (!list_empty(&stream->subrequests)) { @@ -143,7 +138,7 @@ static void netfs_free_request(struct work_struct *work) } kvfree(rreq->direct_bv); } - netfs_clear_buffer(rreq); + rolling_buffer_clear(&rreq->buffer); if (atomic_dec_and_test(&ictx->io_count)) wake_up_var(&ictx->io_count); diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 8878b46589ff..23c75755ad4e 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -14,6 +14,14 @@ #include <linux/task_io_accounting_ops.h> #include "internal.h" +/* Notes made in the collector */ +#define HIT_PENDING 0x01 /* A front op was still pending */ +#define MADE_PROGRESS 0x04 /* Made progress cleaning up a stream or the folio set */ +#define BUFFERED 0x08 /* The pagecache needs cleaning up */ +#define NEED_RETRY 0x10 /* A front op requests retrying */ +#define COPY_TO_CACHE 0x40 /* Need to copy subrequest to cache */ +#define ABANDON_SREQ 0x80 /* Need to abandon untransferred part of subrequest */ + /* * Clear the unread part of an I/O request. */ @@ -31,14 +39,18 @@ static void netfs_clear_unread(struct netfs_io_subrequest *subreq) * cache the folio, we set the group to NETFS_FOLIO_COPY_TO_CACHE, mark it * dirty and let writeback handle it. */ -static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, - struct netfs_io_request *rreq, +static void netfs_unlock_read_folio(struct netfs_io_request *rreq, struct folio_queue *folioq, int slot) { struct netfs_folio *finfo; struct folio *folio = folioq_folio(folioq, slot); + if (unlikely(folio_pos(folio) < rreq->abandon_to)) { + trace_netfs_folio(folio, netfs_folio_trace_abandon); + goto just_unlock; + } + flush_dcache_folio(folio); folio_mark_uptodate(folio); @@ -53,7 +65,7 @@ static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, kfree(finfo); } - if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) { + if (test_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags)) { if (!WARN_ON_ONCE(folio_get_private(folio) != NULL)) { trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); folio_attach_private(folio, NETFS_FOLIO_COPY_TO_CACHE); @@ -66,12 +78,11 @@ static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, folioq_clear(folioq, slot); } else { // TODO: Use of PG_private_2 is deprecated. - if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) - netfs_pgpriv2_mark_copy_to_cache(subreq, rreq, folioq, slot); - else - folioq_clear(folioq, slot); + if (test_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags)) + netfs_pgpriv2_copy_to_cache(rreq, folio); } +just_unlock: if (!test_bit(NETFS_RREQ_DONT_UNLOCK_FOLIOS, &rreq->flags)) { if (folio->index == rreq->no_unlock_folio && test_bit(NETFS_RREQ_NO_UNLOCK_FOLIO, &rreq->flags)) { @@ -81,239 +92,249 @@ static void netfs_unlock_read_folio(struct netfs_io_subrequest *subreq, folio_unlock(folio); } } + + folioq_clear(folioq, slot); } /* - * Unlock any folios that are now completely read. Returns true if the - * subrequest is removed from the list. + * Unlock any folios we've finished with. */ -static bool netfs_consume_read_data(struct netfs_io_subrequest *subreq, bool was_async) +static void netfs_read_unlock_folios(struct netfs_io_request *rreq, + unsigned int *notes) { - struct netfs_io_subrequest *prev, *next; - struct netfs_io_request *rreq = subreq->rreq; - struct folio_queue *folioq = subreq->curr_folioq; - size_t avail, prev_donated, next_donated, fsize, part, excess; - loff_t fpos, start; - loff_t fend; - int slot = subreq->curr_folioq_slot; - - if (WARN(subreq->transferred > subreq->len, - "Subreq overread: R%x[%x] %zu > %zu", - rreq->debug_id, subreq->debug_index, - subreq->transferred, subreq->len)) - subreq->transferred = subreq->len; - -next_folio: - fsize = PAGE_SIZE << subreq->curr_folio_order; - fpos = round_down(subreq->start + subreq->consumed, fsize); - fend = fpos + fsize; - - if (WARN_ON_ONCE(!folioq) || - WARN_ON_ONCE(!folioq_folio(folioq, slot)) || - WARN_ON_ONCE(folioq_folio(folioq, slot)->index != fpos / PAGE_SIZE)) { - pr_err("R=%08x[%x] s=%llx-%llx ctl=%zx/%zx/%zx sl=%u\n", - rreq->debug_id, subreq->debug_index, - subreq->start, subreq->start + subreq->transferred - 1, - subreq->consumed, subreq->transferred, subreq->len, - slot); - if (folioq) { - struct folio *folio = folioq_folio(folioq, slot); - - pr_err("folioq: orders=%02x%02x%02x%02x\n", - folioq->orders[0], folioq->orders[1], - folioq->orders[2], folioq->orders[3]); - if (folio) - pr_err("folio: %llx-%llx ix=%llx o=%u qo=%u\n", - fpos, fend - 1, folio_pos(folio), folio_order(folio), - folioq_folio_order(folioq, slot)); - } - } + struct folio_queue *folioq = rreq->buffer.tail; + unsigned long long collected_to = rreq->collected_to; + unsigned int slot = rreq->buffer.first_tail_slot; -donation_changed: - /* Try to consume the current folio if we've hit or passed the end of - * it. There's a possibility that this subreq doesn't start at the - * beginning of the folio, in which case we need to donate to/from the - * preceding subreq. - * - * We also need to include any potential donation back from the - * following subreq. - */ - prev_donated = READ_ONCE(subreq->prev_donated); - next_donated = READ_ONCE(subreq->next_donated); - if (prev_donated || next_donated) { - spin_lock_bh(&rreq->lock); - prev_donated = subreq->prev_donated; - next_donated = subreq->next_donated; - subreq->start -= prev_donated; - subreq->len += prev_donated; - subreq->transferred += prev_donated; - prev_donated = subreq->prev_donated = 0; - if (subreq->transferred == subreq->len) { - subreq->len += next_donated; - subreq->transferred += next_donated; - next_donated = subreq->next_donated = 0; + if (rreq->cleaned_to >= rreq->collected_to) + return; + + // TODO: Begin decryption + + if (slot >= folioq_nr_slots(folioq)) { + folioq = rolling_buffer_delete_spent(&rreq->buffer); + if (!folioq) { + rreq->front_folio_order = 0; + return; } - trace_netfs_sreq(subreq, netfs_sreq_trace_add_donations); - spin_unlock_bh(&rreq->lock); + slot = 0; } - avail = subreq->transferred; - if (avail == subreq->len) - avail += next_donated; - start = subreq->start; - if (subreq->consumed == 0) { - start -= prev_donated; - avail += prev_donated; - } else { - start += subreq->consumed; - avail -= subreq->consumed; - } - part = umin(avail, fsize); - - trace_netfs_progress(subreq, start, avail, part); - - if (start + avail >= fend) { - if (fpos == start) { - /* Flush, unlock and mark for caching any folio we've just read. */ - subreq->consumed = fend - subreq->start; - netfs_unlock_read_folio(subreq, rreq, folioq, slot); - folioq_mark2(folioq, slot); - if (subreq->consumed >= subreq->len) - goto remove_subreq; - } else if (fpos < start) { - excess = fend - subreq->start; - - spin_lock_bh(&rreq->lock); - /* If we complete first on a folio split with the - * preceding subreq, donate to that subreq - otherwise - * we get the responsibility. - */ - if (subreq->prev_donated != prev_donated) { - spin_unlock_bh(&rreq->lock); - goto donation_changed; - } + for (;;) { + struct folio *folio; + unsigned long long fpos, fend; + unsigned int order; + size_t fsize; - if (list_is_first(&subreq->rreq_link, &rreq->subrequests)) { - spin_unlock_bh(&rreq->lock); - pr_err("Can't donate prior to front\n"); - goto bad; - } + if (*notes & COPY_TO_CACHE) + set_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags); - prev = list_prev_entry(subreq, rreq_link); - WRITE_ONCE(prev->next_donated, prev->next_donated + excess); - subreq->start += excess; - subreq->len -= excess; - subreq->transferred -= excess; - trace_netfs_donate(rreq, subreq, prev, excess, - netfs_trace_donate_tail_to_prev); - trace_netfs_sreq(subreq, netfs_sreq_trace_donate_to_prev); - - if (subreq->consumed >= subreq->len) - goto remove_subreq_locked; - spin_unlock_bh(&rreq->lock); - } else { - pr_err("fpos > start\n"); - goto bad; - } + folio = folioq_folio(folioq, slot); + if (WARN_ONCE(!folio_test_locked(folio), + "R=%08x: folio %lx is not locked\n", + rreq->debug_id, folio->index)) + trace_netfs_folio(folio, netfs_folio_trace_not_locked); + + order = folioq_folio_order(folioq, slot); + rreq->front_folio_order = order; + fsize = PAGE_SIZE << order; + fpos = folio_pos(folio); + fend = umin(fpos + fsize, rreq->i_size); + + trace_netfs_collect_folio(rreq, folio, fend, collected_to); - /* Advance the rolling buffer to the next folio. */ + /* Unlock any folio we've transferred all of. */ + if (collected_to < fend) + break; + + netfs_unlock_read_folio(rreq, folioq, slot); + WRITE_ONCE(rreq->cleaned_to, fpos + fsize); + *notes |= MADE_PROGRESS; + + clear_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags); + + /* Clean up the head folioq. If we clear an entire folioq, then + * we can get rid of it provided it's not also the tail folioq + * being filled by the issuer. + */ + folioq_clear(folioq, slot); slot++; if (slot >= folioq_nr_slots(folioq)) { + folioq = rolling_buffer_delete_spent(&rreq->buffer); + if (!folioq) + goto done; slot = 0; - folioq = folioq->next; - subreq->curr_folioq = folioq; + trace_netfs_folioq(folioq, netfs_trace_folioq_read_progress); } - subreq->curr_folioq_slot = slot; - if (folioq && folioq_folio(folioq, slot)) - subreq->curr_folio_order = folioq->orders[slot]; - if (!was_async) - cond_resched(); - goto next_folio; + + if (fpos + fsize >= collected_to) + break; } - /* Deal with partial progress. */ - if (subreq->transferred < subreq->len) - return false; + rreq->buffer.tail = folioq; +done: + rreq->buffer.first_tail_slot = slot; +} - /* Donate the remaining downloaded data to one of the neighbouring - * subrequests. Note that we may race with them doing the same thing. +/* + * Collect and assess the results of various read subrequests. We may need to + * retry some of the results. + * + * Note that we have a sequence of subrequests, which may be drawing on + * different sources and may or may not be the same size or starting position + * and may not even correspond in boundary alignment. + */ +static void netfs_collect_read_results(struct netfs_io_request *rreq) +{ + struct netfs_io_subrequest *front, *remove; + struct netfs_io_stream *stream = &rreq->io_streams[0]; + unsigned int notes; + + _enter("%llx-%llx", rreq->start, rreq->start + rreq->len); + trace_netfs_rreq(rreq, netfs_rreq_trace_collect); + trace_netfs_collect(rreq); + +reassess: + if (rreq->origin == NETFS_READAHEAD || + rreq->origin == NETFS_READPAGE || + rreq->origin == NETFS_READ_FOR_WRITE) + notes = BUFFERED; + else + notes = 0; + + /* Remove completed subrequests from the front of the stream and + * advance the completion point. We stop when we hit something that's + * in progress. The issuer thread may be adding stuff to the tail + * whilst we're doing this. */ - spin_lock_bh(&rreq->lock); + front = READ_ONCE(stream->front); + while (front) { + size_t transferred; - if (subreq->prev_donated != prev_donated || - subreq->next_donated != next_donated) { - spin_unlock_bh(&rreq->lock); - cond_resched(); - goto donation_changed; - } + trace_netfs_collect_sreq(rreq, front); + _debug("sreq [%x] %llx %zx/%zx", + front->debug_index, front->start, front->transferred, front->len); - /* Deal with the trickiest case: that this subreq is in the middle of a - * folio, not touching either edge, but finishes first. In such a - * case, we donate to the previous subreq, if there is one and if it is - * contiguous, so that the donation is only handled when that completes - * - and remove this subreq from the list. - * - * If the previous subreq finished first, we will have acquired their - * donation and should be able to unlock folios and/or donate nextwards. - */ - if (!subreq->consumed && - !prev_donated && - !list_is_first(&subreq->rreq_link, &rreq->subrequests)) { - prev = list_prev_entry(subreq, rreq_link); - if (subreq->start == prev->start + prev->len) { - WRITE_ONCE(prev->next_donated, prev->next_donated + subreq->len); - subreq->start += subreq->len; - subreq->len = 0; - subreq->transferred = 0; - trace_netfs_donate(rreq, subreq, prev, subreq->len, - netfs_trace_donate_to_prev); - trace_netfs_sreq(subreq, netfs_sreq_trace_donate_to_prev); - goto remove_subreq_locked; + if (stream->collected_to < front->start) { + trace_netfs_collect_gap(rreq, stream, front->start, 'F'); + stream->collected_to = front->start; + } + + if (test_bit(NETFS_SREQ_IN_PROGRESS, &front->flags)) + notes |= HIT_PENDING; + smp_rmb(); /* Read counters after IN_PROGRESS flag. */ + transferred = READ_ONCE(front->transferred); + + /* If we can now collect the next folio, do so. We don't want + * to defer this as we have to decide whether we need to copy + * to the cache or not, and that may differ between adjacent + * subreqs. + */ + if (notes & BUFFERED) { + size_t fsize = PAGE_SIZE << rreq->front_folio_order; + + /* Clear the tail of a short read. */ + if (!(notes & HIT_PENDING) && + front->error == 0 && + transferred < front->len && + (test_bit(NETFS_SREQ_HIT_EOF, &front->flags) || + test_bit(NETFS_SREQ_CLEAR_TAIL, &front->flags))) { + netfs_clear_unread(front); + transferred = front->transferred = front->len; + trace_netfs_sreq(front, netfs_sreq_trace_clear); + } + + stream->collected_to = front->start + transferred; + rreq->collected_to = stream->collected_to; + + if (test_bit(NETFS_SREQ_COPY_TO_CACHE, &front->flags)) + notes |= COPY_TO_CACHE; + + if (test_bit(NETFS_SREQ_FAILED, &front->flags)) { + rreq->abandon_to = front->start + front->len; + front->transferred = front->len; + transferred = front->len; + trace_netfs_rreq(rreq, netfs_rreq_trace_set_abandon); + } + if (front->start + transferred >= rreq->cleaned_to + fsize || + test_bit(NETFS_SREQ_HIT_EOF, &front->flags)) + netfs_read_unlock_folios(rreq, ¬es); + } else { + stream->collected_to = front->start + transferred; + rreq->collected_to = stream->collected_to; } + + /* Stall if the front is still undergoing I/O. */ + if (notes & HIT_PENDING) + break; + + if (test_bit(NETFS_SREQ_FAILED, &front->flags)) { + if (!stream->failed) { + stream->error = front->error; + rreq->error = front->error; + set_bit(NETFS_RREQ_FAILED, &rreq->flags); + stream->failed = true; + } + notes |= MADE_PROGRESS | ABANDON_SREQ; + } else if (test_bit(NETFS_SREQ_NEED_RETRY, &front->flags)) { + stream->need_retry = true; + notes |= NEED_RETRY | MADE_PROGRESS; + break; + } else { + if (!stream->failed) + stream->transferred = stream->collected_to - rreq->start; + notes |= MADE_PROGRESS; + } + + /* Remove if completely consumed. */ + stream->source = front->source; + spin_lock(&rreq->lock); + + remove = front; + trace_netfs_sreq(front, netfs_sreq_trace_discard); + list_del_init(&front->rreq_link); + front = list_first_entry_or_null(&stream->subrequests, + struct netfs_io_subrequest, rreq_link); + stream->front = front; + spin_unlock(&rreq->lock); + netfs_put_subrequest(remove, false, + notes & ABANDON_SREQ ? + netfs_sreq_trace_put_abandon : + netfs_sreq_trace_put_done); } - /* If we can't donate down the chain, donate up the chain instead. */ - excess = subreq->len - subreq->consumed + next_donated; + trace_netfs_collect_stream(rreq, stream); + trace_netfs_collect_state(rreq, rreq->collected_to, notes); - if (!subreq->consumed) - excess += prev_donated; + if (!(notes & BUFFERED)) + rreq->cleaned_to = rreq->collected_to; - if (list_is_last(&subreq->rreq_link, &rreq->subrequests)) { - rreq->prev_donated = excess; - trace_netfs_donate(rreq, subreq, NULL, excess, - netfs_trace_donate_to_deferred_next); - } else { - next = list_next_entry(subreq, rreq_link); - WRITE_ONCE(next->prev_donated, excess); - trace_netfs_donate(rreq, subreq, next, excess, - netfs_trace_donate_to_next); + if (notes & NEED_RETRY) + goto need_retry; + if ((notes & MADE_PROGRESS) && test_bit(NETFS_RREQ_PAUSE, &rreq->flags)) { + trace_netfs_rreq(rreq, netfs_rreq_trace_unpause); + clear_bit_unlock(NETFS_RREQ_PAUSE, &rreq->flags); + smp_mb__after_atomic(); /* Set PAUSE before task state */ + wake_up(&rreq->waitq); + } + + if (notes & MADE_PROGRESS) { + //cond_resched(); + goto reassess; } - trace_netfs_sreq(subreq, netfs_sreq_trace_donate_to_next); - subreq->len = subreq->consumed; - subreq->transferred = subreq->consumed; - goto remove_subreq_locked; - -remove_subreq: - spin_lock_bh(&rreq->lock); -remove_subreq_locked: - subreq->consumed = subreq->len; - list_del(&subreq->rreq_link); - spin_unlock_bh(&rreq->lock); - netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_consumed); - return true; - -bad: - /* Errr... prev and next both donated to us, but insufficient to finish - * the folio. + +out: + _leave(" = %x", notes); + return; + +need_retry: + /* Okay... We're going to have to retry parts of the stream. Note + * that any partially completed op will have had any wholly transferred + * folios removed from it. */ - printk("R=%08x[%x] s=%llx-%llx %zx/%zx/%zx\n", - rreq->debug_id, subreq->debug_index, - subreq->start, subreq->start + subreq->transferred - 1, - subreq->consumed, subreq->transferred, subreq->len); - printk("folio: %llx-%llx\n", fpos, fend - 1); - printk("donated: prev=%zx next=%zx\n", prev_donated, next_donated); - printk("s=%llx av=%zx part=%zx\n", start, avail, part); - BUG(); + _debug("retry"); + netfs_retry_reads(rreq); + goto out; } /* @@ -322,12 +343,13 @@ bad: static void netfs_rreq_assess_dio(struct netfs_io_request *rreq) { struct netfs_io_subrequest *subreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; unsigned int i; /* Collect unbuffered reads and direct reads, adding up the transfer * sizes until we find the first short or failed subrequest. */ - list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { + list_for_each_entry(subreq, &stream->subrequests, rreq_link) { rreq->transferred += subreq->transferred; if (subreq->transferred < subreq->len || @@ -360,25 +382,67 @@ static void netfs_rreq_assess_dio(struct netfs_io_request *rreq) } /* - * Assess the state of a read request and decide what to do next. + * Do processing after reading a monolithic single object. + */ +static void netfs_rreq_assess_single(struct netfs_io_request *rreq) +{ + struct netfs_io_stream *stream = &rreq->io_streams[0]; + + if (!rreq->error && stream->source == NETFS_DOWNLOAD_FROM_SERVER && + fscache_resources_valid(&rreq->cache_resources)) { + trace_netfs_rreq(rreq, netfs_rreq_trace_dirty); + netfs_single_mark_inode_dirty(rreq->inode); + } + + if (rreq->iocb) { + rreq->iocb->ki_pos += rreq->transferred; + if (rreq->iocb->ki_complete) + rreq->iocb->ki_complete( + rreq->iocb, rreq->error ? rreq->error : rreq->transferred); + } + if (rreq->netfs_ops->done) + rreq->netfs_ops->done(rreq); +} + +/* + * Perform the collection of subrequests and folios. * * Note that we're in normal kernel thread context at this point, possibly * running on a workqueue. */ -static void netfs_rreq_assess(struct netfs_io_request *rreq) +static void netfs_read_collection(struct netfs_io_request *rreq) { - trace_netfs_rreq(rreq, netfs_rreq_trace_assess); + struct netfs_io_stream *stream = &rreq->io_streams[0]; - //netfs_rreq_is_still_valid(rreq); + netfs_collect_read_results(rreq); - if (test_and_clear_bit(NETFS_RREQ_NEED_RETRY, &rreq->flags)) { - netfs_retry_reads(rreq); + /* We're done when the app thread has finished posting subreqs and the + * queue is empty. + */ + if (!test_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags)) return; - } + smp_rmb(); /* Read ALL_QUEUED before subreq lists. */ + + if (!list_empty(&stream->subrequests)) + return; + + /* Okay, declare that all I/O is complete. */ + rreq->transferred = stream->transferred; + trace_netfs_rreq(rreq, netfs_rreq_trace_complete); - if (rreq->origin == NETFS_DIO_READ || - rreq->origin == NETFS_READ_GAPS) + //netfs_rreq_is_still_valid(rreq); + + switch (rreq->origin) { + case NETFS_DIO_READ: + case NETFS_READ_GAPS: netfs_rreq_assess_dio(rreq); + break; + case NETFS_READ_SINGLE: + netfs_rreq_assess_single(rreq); + break; + default: + break; + } task_io_account_read(rreq->transferred); trace_netfs_rreq(rreq, netfs_rreq_trace_wake_ip); @@ -387,61 +451,67 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq) trace_netfs_rreq(rreq, netfs_rreq_trace_done); netfs_clear_subrequests(rreq, false); netfs_unlock_abandoned_read_pages(rreq); - if (unlikely(test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags))) - netfs_pgpriv2_write_to_the_cache(rreq); + if (unlikely(rreq->copy_to_cache)) + netfs_pgpriv2_end_copy_to_cache(rreq); } -void netfs_read_termination_worker(struct work_struct *work) +void netfs_read_collection_worker(struct work_struct *work) { - struct netfs_io_request *rreq = - container_of(work, struct netfs_io_request, work); + struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work); + netfs_see_request(rreq, netfs_rreq_trace_see_work); - netfs_rreq_assess(rreq); - netfs_put_request(rreq, false, netfs_rreq_trace_put_work_complete); + if (test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) + netfs_read_collection(rreq); + netfs_put_request(rreq, false, netfs_rreq_trace_put_work); } /* - * Handle the completion of all outstanding I/O operations on a read request. - * We inherit a ref from the caller. + * Wake the collection work item. */ -void netfs_rreq_terminated(struct netfs_io_request *rreq, bool was_async) +void netfs_wake_read_collector(struct netfs_io_request *rreq) { - if (!was_async) - return netfs_rreq_assess(rreq); - if (!work_pending(&rreq->work)) { - netfs_get_request(rreq, netfs_rreq_trace_get_work); - if (!queue_work(system_unbound_wq, &rreq->work)) - netfs_put_request(rreq, was_async, netfs_rreq_trace_put_work_nq); + if (test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags) && + !test_bit(NETFS_RREQ_RETRYING, &rreq->flags)) { + if (!work_pending(&rreq->work)) { + netfs_get_request(rreq, netfs_rreq_trace_get_work); + if (!queue_work(system_unbound_wq, &rreq->work)) + netfs_put_request(rreq, true, netfs_rreq_trace_put_work_nq); + } + } else { + trace_netfs_rreq(rreq, netfs_rreq_trace_wake_queue); + wake_up(&rreq->waitq); } } /** * netfs_read_subreq_progress - Note progress of a read operation. * @subreq: The read request that has terminated. - * @was_async: True if we're in an asynchronous context. * * This tells the read side of netfs lib that a contributory I/O operation has * made some progress and that it may be possible to unlock some folios. * * Before calling, the filesystem should update subreq->transferred to track * the amount of data copied into the output buffer. - * - * If @was_async is true, the caller might be running in softirq or interrupt - * context and we can't sleep. */ -void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq, - bool was_async) +void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq) { struct netfs_io_request *rreq = subreq->rreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; + size_t fsize = PAGE_SIZE << rreq->front_folio_order; trace_netfs_sreq(subreq, netfs_sreq_trace_progress); - if (subreq->transferred > subreq->consumed && + /* If we are at the head of the queue, wake up the collector, + * getting a ref to it if we were the ones to do so. + */ + if (subreq->start + subreq->transferred > rreq->cleaned_to + fsize && (rreq->origin == NETFS_READAHEAD || rreq->origin == NETFS_READPAGE || - rreq->origin == NETFS_READ_FOR_WRITE)) { - netfs_consume_read_data(subreq, was_async); + rreq->origin == NETFS_READ_FOR_WRITE) && + list_is_first(&subreq->rreq_link, &stream->subrequests) + ) { __set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); + netfs_wake_read_collector(rreq); } } EXPORT_SYMBOL(netfs_read_subreq_progress); @@ -449,27 +519,23 @@ EXPORT_SYMBOL(netfs_read_subreq_progress); /** * netfs_read_subreq_terminated - Note the termination of an I/O operation. * @subreq: The I/O request that has terminated. - * @error: Error code indicating type of completion. - * @was_async: The termination was asynchronous * * This tells the read helper that a contributory I/O operation has terminated, * one way or another, and that it should integrate the results. * - * The caller indicates the outcome of the operation through @error, supplying - * 0 to indicate a successful or retryable transfer (if NETFS_SREQ_NEED_RETRY - * is set) or a negative error code. The helper will look after reissuing I/O - * operations as appropriate and writing downloaded data to the cache. + * The caller indicates the outcome of the operation through @subreq->error, + * supplying 0 to indicate a successful or retryable transfer (if + * NETFS_SREQ_NEED_RETRY is set) or a negative error code. The helper will + * look after reissuing I/O operations as appropriate and writing downloaded + * data to the cache. * * Before calling, the filesystem should update subreq->transferred to track * the amount of data copied into the output buffer. - * - * If @was_async is true, the caller might be running in softirq or interrupt - * context and we can't sleep. */ -void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq, - int error, bool was_async) +void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq) { struct netfs_io_request *rreq = subreq->rreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; switch (subreq->source) { case NETFS_READ_FROM_CACHE: @@ -482,71 +548,159 @@ void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq, break; } - if (rreq->origin != NETFS_DIO_READ) { - /* Collect buffered reads. - * - * If the read completed validly short, then we can clear the - * tail before going on to unlock the folios. - */ - if (error == 0 && subreq->transferred < subreq->len && - (test_bit(NETFS_SREQ_HIT_EOF, &subreq->flags) || - test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags))) { - netfs_clear_unread(subreq); - subreq->transferred = subreq->len; - trace_netfs_sreq(subreq, netfs_sreq_trace_clear); - } - if (subreq->transferred > subreq->consumed && - (rreq->origin == NETFS_READAHEAD || - rreq->origin == NETFS_READPAGE || - rreq->origin == NETFS_READ_FOR_WRITE)) { - netfs_consume_read_data(subreq, was_async); - __set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); - } - rreq->transferred += subreq->transferred; - } - /* Deal with retry requests, short reads and errors. If we retry * but don't make progress, we abandon the attempt. */ - if (!error && subreq->transferred < subreq->len) { + if (!subreq->error && subreq->transferred < subreq->len) { if (test_bit(NETFS_SREQ_HIT_EOF, &subreq->flags)) { trace_netfs_sreq(subreq, netfs_sreq_trace_hit_eof); + } else if (test_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags)) { + trace_netfs_sreq(subreq, netfs_sreq_trace_need_clear); + } else if (test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) { + trace_netfs_sreq(subreq, netfs_sreq_trace_need_retry); + } else if (test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags)) { + __set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); + trace_netfs_sreq(subreq, netfs_sreq_trace_partial_read); } else { + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); + subreq->error = -ENODATA; trace_netfs_sreq(subreq, netfs_sreq_trace_short); - if (subreq->transferred > subreq->consumed) { - /* If we didn't read new data, abandon retry. */ - if (subreq->retry_count && - test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags)) { - __set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); - set_bit(NETFS_RREQ_NEED_RETRY, &rreq->flags); - } - } else if (test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags)) { - __set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); - set_bit(NETFS_RREQ_NEED_RETRY, &rreq->flags); - } else { - __set_bit(NETFS_SREQ_FAILED, &subreq->flags); - error = -ENODATA; - } } } - subreq->error = error; - trace_netfs_sreq(subreq, netfs_sreq_trace_terminated); - - if (unlikely(error < 0)) { - trace_netfs_failure(rreq, subreq, error, netfs_fail_read); + if (unlikely(subreq->error < 0)) { + trace_netfs_failure(rreq, subreq, subreq->error, netfs_fail_read); if (subreq->source == NETFS_READ_FROM_CACHE) { netfs_stat(&netfs_n_rh_read_failed); + __set_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); } else { netfs_stat(&netfs_n_rh_download_failed); - set_bit(NETFS_RREQ_FAILED, &rreq->flags); - rreq->error = subreq->error; + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); } + trace_netfs_rreq(rreq, netfs_rreq_trace_set_pause); + set_bit(NETFS_RREQ_PAUSE, &rreq->flags); } - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_terminated(rreq, was_async); + trace_netfs_sreq(subreq, netfs_sreq_trace_terminated); + + clear_bit_unlock(NETFS_SREQ_IN_PROGRESS, &subreq->flags); + smp_mb__after_atomic(); /* Clear IN_PROGRESS before task state */ - netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated); + /* If we are at the head of the queue, wake up the collector. */ + if (list_is_first(&subreq->rreq_link, &stream->subrequests) || + test_bit(NETFS_RREQ_RETRYING, &rreq->flags)) + netfs_wake_read_collector(rreq); + + netfs_put_subrequest(subreq, true, netfs_sreq_trace_put_terminated); } EXPORT_SYMBOL(netfs_read_subreq_terminated); + +/* + * Handle termination of a read from the cache. + */ +void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error, bool was_async) +{ + struct netfs_io_subrequest *subreq = priv; + + if (transferred_or_error > 0) { + subreq->error = 0; + if (transferred_or_error > 0) { + subreq->transferred += transferred_or_error; + __set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); + } + } else { + subreq->error = transferred_or_error; + } + netfs_read_subreq_terminated(subreq); +} + +/* + * Wait for the read operation to complete, successfully or otherwise. + */ +ssize_t netfs_wait_for_read(struct netfs_io_request *rreq) +{ + struct netfs_io_subrequest *subreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; + DEFINE_WAIT(myself); + ssize_t ret; + + for (;;) { + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue); + prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE); + + subreq = list_first_entry_or_null(&stream->subrequests, + struct netfs_io_subrequest, rreq_link); + if (subreq && + (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) || + test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) { + __set_current_state(TASK_RUNNING); + netfs_read_collection(rreq); + continue; + } + + if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags)) + break; + + schedule(); + trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue); + } + + finish_wait(&rreq->waitq, &myself); + + ret = rreq->error; + if (ret == 0) { + ret = rreq->transferred; + switch (rreq->origin) { + case NETFS_DIO_READ: + case NETFS_READ_SINGLE: + ret = rreq->transferred; + break; + default: + if (rreq->submitted < rreq->len) { + trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read); + ret = -EIO; + } + break; + } + } + + return ret; +} + +/* + * Wait for a paused read operation to unpause or complete in some manner. + */ +void netfs_wait_for_pause(struct netfs_io_request *rreq) +{ + struct netfs_io_subrequest *subreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; + DEFINE_WAIT(myself); + + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_pause); + + for (;;) { + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue); + prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE); + + if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) { + subreq = list_first_entry_or_null(&stream->subrequests, + struct netfs_io_subrequest, rreq_link); + if (subreq && + (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) || + test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) { + __set_current_state(TASK_RUNNING); + netfs_read_collection(rreq); + continue; + } + } + + if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags) || + !test_bit(NETFS_RREQ_PAUSE, &rreq->flags)) + break; + + schedule(); + trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue); + } + + finish_wait(&rreq->waitq, &myself); +} diff --git a/fs/netfs/read_pgpriv2.c b/fs/netfs/read_pgpriv2.c index e72f5e674834..cf7727060215 100644 --- a/fs/netfs/read_pgpriv2.c +++ b/fs/netfs/read_pgpriv2.c @@ -14,52 +14,11 @@ #include "internal.h" /* - * [DEPRECATED] Mark page as requiring copy-to-cache using PG_private_2. The - * third mark in the folio queue is used to indicate that this folio needs - * writing. - */ -void netfs_pgpriv2_mark_copy_to_cache(struct netfs_io_subrequest *subreq, - struct netfs_io_request *rreq, - struct folio_queue *folioq, - int slot) -{ - struct folio *folio = folioq_folio(folioq, slot); - - trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); - folio_start_private_2(folio); - folioq_mark3(folioq, slot); -} - -/* - * [DEPRECATED] Cancel PG_private_2 on all marked folios in the event of an - * unrecoverable error. - */ -static void netfs_pgpriv2_cancel(struct folio_queue *folioq) -{ - struct folio *folio; - int slot; - - while (folioq) { - if (!folioq->marks3) { - folioq = folioq->next; - continue; - } - - slot = __ffs(folioq->marks3); - folio = folioq_folio(folioq, slot); - - trace_netfs_folio(folio, netfs_folio_trace_cancel_copy); - folio_end_private_2(folio); - folioq_unmark3(folioq, slot); - } -} - -/* * [DEPRECATED] Copy a folio to the cache with PG_private_2 set. */ -static int netfs_pgpriv2_copy_folio(struct netfs_io_request *wreq, struct folio *folio) +static void netfs_pgpriv2_copy_folio(struct netfs_io_request *creq, struct folio *folio) { - struct netfs_io_stream *cache = &wreq->io_streams[1]; + struct netfs_io_stream *cache = &creq->io_streams[1]; size_t fsize = folio_size(folio), flen = fsize; loff_t fpos = folio_pos(folio), i_size; bool to_eof = false; @@ -70,17 +29,17 @@ static int netfs_pgpriv2_copy_folio(struct netfs_io_request *wreq, struct folio * of the page to beyond it, but cannot move i_size into or through the * page since we have it locked. */ - i_size = i_size_read(wreq->inode); + i_size = i_size_read(creq->inode); if (fpos >= i_size) { /* mmap beyond eof. */ _debug("beyond eof"); folio_end_private_2(folio); - return 0; + return; } - if (fpos + fsize > wreq->i_size) - wreq->i_size = i_size; + if (fpos + fsize > creq->i_size) + creq->i_size = i_size; if (flen > i_size - fpos) { flen = i_size - fpos; @@ -94,8 +53,10 @@ static int netfs_pgpriv2_copy_folio(struct netfs_io_request *wreq, struct folio trace_netfs_folio(folio, netfs_folio_trace_store_copy); /* Attach the folio to the rolling buffer. */ - if (netfs_buffer_append_folio(wreq, folio, false) < 0) - return -ENOMEM; + if (rolling_buffer_append(&creq->buffer, folio, 0) < 0) { + clear_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &creq->flags); + return; + } cache->submit_extendable_to = fsize; cache->submit_off = 0; @@ -109,11 +70,11 @@ static int netfs_pgpriv2_copy_folio(struct netfs_io_request *wreq, struct folio do { ssize_t part; - wreq->io_iter.iov_offset = cache->submit_off; + creq->buffer.iter.iov_offset = cache->submit_off; - atomic64_set(&wreq->issued_to, fpos + cache->submit_off); + atomic64_set(&creq->issued_to, fpos + cache->submit_off); cache->submit_extendable_to = fsize - cache->submit_off; - part = netfs_advance_write(wreq, cache, fpos + cache->submit_off, + part = netfs_advance_write(creq, cache, fpos + cache->submit_off, cache->submit_len, to_eof); cache->submit_off += part; if (part > cache->submit_len) @@ -122,99 +83,95 @@ static int netfs_pgpriv2_copy_folio(struct netfs_io_request *wreq, struct folio cache->submit_len -= part; } while (cache->submit_len > 0); - wreq->io_iter.iov_offset = 0; - iov_iter_advance(&wreq->io_iter, fsize); - atomic64_set(&wreq->issued_to, fpos + fsize); + creq->buffer.iter.iov_offset = 0; + rolling_buffer_advance(&creq->buffer, fsize); + atomic64_set(&creq->issued_to, fpos + fsize); if (flen < fsize) - netfs_issue_write(wreq, cache); - - _leave(" = 0"); - return 0; + netfs_issue_write(creq, cache); } /* - * [DEPRECATED] Go through the buffer and write any folios that are marked with - * the third mark to the cache. + * [DEPRECATED] Set up copying to the cache. */ -void netfs_pgpriv2_write_to_the_cache(struct netfs_io_request *rreq) +static struct netfs_io_request *netfs_pgpriv2_begin_copy_to_cache( + struct netfs_io_request *rreq, struct folio *folio) { - struct netfs_io_request *wreq; - struct folio_queue *folioq; - struct folio *folio; - int error = 0; - int slot = 0; - - _enter(""); + struct netfs_io_request *creq; if (!fscache_resources_valid(&rreq->cache_resources)) - goto couldnt_start; + goto cancel; - /* Need the first folio to be able to set up the op. */ - for (folioq = rreq->buffer; folioq; folioq = folioq->next) { - if (folioq->marks3) { - slot = __ffs(folioq->marks3); - break; - } - } - if (!folioq) - return; - folio = folioq_folio(folioq, slot); - - wreq = netfs_create_write_req(rreq->mapping, NULL, folio_pos(folio), + creq = netfs_create_write_req(rreq->mapping, NULL, folio_pos(folio), NETFS_PGPRIV2_COPY_TO_CACHE); - if (IS_ERR(wreq)) { - kleave(" [create %ld]", PTR_ERR(wreq)); - goto couldnt_start; - } + if (IS_ERR(creq)) + goto cancel; - trace_netfs_write(wreq, netfs_write_trace_copy_to_cache); + if (!creq->io_streams[1].avail) + goto cancel_put; + + trace_netfs_write(creq, netfs_write_trace_copy_to_cache); netfs_stat(&netfs_n_wh_copy_to_cache); - if (!wreq->io_streams[1].avail) { - netfs_put_request(wreq, false, netfs_rreq_trace_put_return); - goto couldnt_start; - } + rreq->copy_to_cache = creq; + return creq; + +cancel_put: + netfs_put_request(creq, false, netfs_rreq_trace_put_return); +cancel: + rreq->copy_to_cache = ERR_PTR(-ENOBUFS); + clear_bit(NETFS_RREQ_FOLIO_COPY_TO_CACHE, &rreq->flags); + return ERR_PTR(-ENOBUFS); +} - for (;;) { - error = netfs_pgpriv2_copy_folio(wreq, folio); - if (error < 0) - break; +/* + * [DEPRECATED] Mark page as requiring copy-to-cache using PG_private_2 and add + * it to the copy write request. + */ +void netfs_pgpriv2_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio) +{ + struct netfs_io_request *creq = rreq->copy_to_cache; - folioq_unmark3(folioq, slot); - while (!folioq->marks3) { - folioq = folioq->next; - if (!folioq) - goto end_of_queue; - } + if (!creq) + creq = netfs_pgpriv2_begin_copy_to_cache(rreq, folio); + if (IS_ERR(creq)) + return; - slot = __ffs(folioq->marks3); - folio = folioq_folio(folioq, slot); - } + trace_netfs_folio(folio, netfs_folio_trace_copy_to_cache); + folio_start_private_2(folio); + netfs_pgpriv2_copy_folio(creq, folio); +} -end_of_queue: - netfs_issue_write(wreq, &wreq->io_streams[1]); +/* + * [DEPRECATED] End writing to the cache, flushing out any outstanding writes. + */ +void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq) +{ + struct netfs_io_request *creq = rreq->copy_to_cache; + + if (IS_ERR_OR_NULL(creq)) + return; + + netfs_issue_write(creq, &creq->io_streams[1]); smp_wmb(); /* Write lists before ALL_QUEUED. */ - set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags); + set_bit(NETFS_RREQ_ALL_QUEUED, &creq->flags); - netfs_put_request(wreq, false, netfs_rreq_trace_put_return); - _leave(" = %d", error); -couldnt_start: - netfs_pgpriv2_cancel(rreq->buffer); + netfs_put_request(creq, false, netfs_rreq_trace_put_return); + creq->copy_to_cache = NULL; } /* * [DEPRECATED] Remove the PG_private_2 mark from any folios we've finished * copying. */ -bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq) +bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *creq) { - struct folio_queue *folioq = wreq->buffer; - unsigned long long collected_to = wreq->collected_to; - unsigned int slot = wreq->buffer_head_slot; + struct folio_queue *folioq = creq->buffer.tail; + unsigned long long collected_to = creq->collected_to; + unsigned int slot = creq->buffer.first_tail_slot; bool made_progress = false; if (slot >= folioq_nr_slots(folioq)) { - folioq = netfs_delete_buffer_head(wreq); + folioq = rolling_buffer_delete_spent(&creq->buffer); slot = 0; } @@ -226,16 +183,16 @@ bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq) folio = folioq_folio(folioq, slot); if (WARN_ONCE(!folio_test_private_2(folio), "R=%08x: folio %lx is not marked private_2\n", - wreq->debug_id, folio->index)) + creq->debug_id, folio->index)) trace_netfs_folio(folio, netfs_folio_trace_not_under_wback); fpos = folio_pos(folio); fsize = folio_size(folio); flen = fsize; - fend = min_t(unsigned long long, fpos + flen, wreq->i_size); + fend = min_t(unsigned long long, fpos + flen, creq->i_size); - trace_netfs_collect_folio(wreq, folio, fend, collected_to); + trace_netfs_collect_folio(creq, folio, fend, collected_to); /* Unlock any folio we've transferred all of. */ if (collected_to < fend) @@ -243,7 +200,7 @@ bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq) trace_netfs_folio(folio, netfs_folio_trace_end_copy); folio_end_private_2(folio); - wreq->cleaned_to = fpos + fsize; + creq->cleaned_to = fpos + fsize; made_progress = true; /* Clean up the head folioq. If we clear an entire folioq, then @@ -253,9 +210,9 @@ bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq) folioq_clear(folioq, slot); slot++; if (slot >= folioq_nr_slots(folioq)) { - if (READ_ONCE(wreq->buffer_tail) == folioq) - break; - folioq = netfs_delete_buffer_head(wreq); + folioq = rolling_buffer_delete_spent(&creq->buffer); + if (!folioq) + goto done; slot = 0; } @@ -263,7 +220,8 @@ bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq) break; } - wreq->buffer = folioq; - wreq->buffer_head_slot = slot; + creq->buffer.tail = folioq; +done: + creq->buffer.first_tail_slot = slot; return made_progress; } diff --git a/fs/netfs/read_retry.c b/fs/netfs/read_retry.c index 16b676c68dcd..0f294b26e08c 100644 --- a/fs/netfs/read_retry.c +++ b/fs/netfs/read_retry.c @@ -12,17 +12,9 @@ static void netfs_reissue_read(struct netfs_io_request *rreq, struct netfs_io_subrequest *subreq) { - struct iov_iter *io_iter = &subreq->io_iter; - - if (iov_iter_is_folioq(io_iter)) { - subreq->curr_folioq = (struct folio_queue *)io_iter->folioq; - subreq->curr_folioq_slot = io_iter->folioq_slot; - subreq->curr_folio_order = subreq->curr_folioq->orders[subreq->curr_folioq_slot]; - } - - atomic_inc(&rreq->nr_outstanding); + __clear_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); - netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); + netfs_stat(&netfs_n_rh_retry_read_subreq); subreq->rreq->netfs_ops->issue_read(subreq); } @@ -33,13 +25,12 @@ static void netfs_reissue_read(struct netfs_io_request *rreq, static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) { struct netfs_io_subrequest *subreq; - struct netfs_io_stream *stream0 = &rreq->io_streams[0]; - LIST_HEAD(sublist); - LIST_HEAD(queue); + struct netfs_io_stream *stream = &rreq->io_streams[0]; + struct list_head *next; _enter("R=%x", rreq->debug_id); - if (list_empty(&rreq->subrequests)) + if (list_empty(&stream->subrequests)) return; if (rreq->netfs_ops->retry_request) @@ -50,15 +41,14 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) */ if (!rreq->netfs_ops->prepare_read && !rreq->cache_resources.ops) { - struct netfs_io_subrequest *subreq; - - list_for_each_entry(subreq, &rreq->subrequests, rreq_link) { + list_for_each_entry(subreq, &stream->subrequests, rreq_link) { if (test_bit(NETFS_SREQ_FAILED, &subreq->flags)) break; if (__test_and_clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) { __clear_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); subreq->retry_count++; netfs_reset_iter(subreq); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); netfs_reissue_read(rreq, subreq); } } @@ -75,48 +65,44 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) * populating with smaller subrequests. In the event that the subreq * we just launched finishes before we insert the next subreq, it'll * fill in rreq->prev_donated instead. - + * * Note: Alternatively, we could split the tail subrequest right before * we reissue it and fix up the donations under lock. */ - list_splice_init(&rreq->subrequests, &queue); + next = stream->subrequests.next; do { - struct netfs_io_subrequest *from; + struct netfs_io_subrequest *from, *to, *tmp; struct iov_iter source; unsigned long long start, len; - size_t part, deferred_next_donated = 0; - bool boundary = false; + size_t part; + bool boundary = false, subreq_superfluous = false; /* Go through the subreqs and find the next span of contiguous * buffer that we then rejig (cifs, for example, needs the * rsize renegotiating) and reissue. */ - from = list_first_entry(&queue, struct netfs_io_subrequest, rreq_link); - list_move_tail(&from->rreq_link, &sublist); + from = list_entry(next, struct netfs_io_subrequest, rreq_link); + to = from; start = from->start + from->transferred; len = from->len - from->transferred; - _debug("from R=%08x[%x] s=%llx ctl=%zx/%zx/%zx", + _debug("from R=%08x[%x] s=%llx ctl=%zx/%zx", rreq->debug_id, from->debug_index, - from->start, from->consumed, from->transferred, from->len); + from->start, from->transferred, from->len); if (test_bit(NETFS_SREQ_FAILED, &from->flags) || !test_bit(NETFS_SREQ_NEED_RETRY, &from->flags)) goto abandon; - deferred_next_donated = from->next_donated; - while ((subreq = list_first_entry_or_null( - &queue, struct netfs_io_subrequest, rreq_link))) { - if (subreq->start != start + len || - subreq->transferred > 0 || + list_for_each_continue(next, &stream->subrequests) { + subreq = list_entry(next, struct netfs_io_subrequest, rreq_link); + if (subreq->start + subreq->transferred != start + len || + test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) || !test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) break; - list_move_tail(&subreq->rreq_link, &sublist); - len += subreq->len; - deferred_next_donated = subreq->next_donated; - if (test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags)) - break; + to = subreq; + len += to->len; } _debug(" - range: %llx-%llx %llx", start, start + len - 1, len); @@ -129,38 +115,33 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) source.count = len; /* Work through the sublist. */ - while ((subreq = list_first_entry_or_null( - &sublist, struct netfs_io_subrequest, rreq_link))) { - list_del(&subreq->rreq_link); - + subreq = from; + list_for_each_entry_from(subreq, &stream->subrequests, rreq_link) { + if (!len) { + subreq_superfluous = true; + break; + } subreq->source = NETFS_DOWNLOAD_FROM_SERVER; subreq->start = start - subreq->transferred; subreq->len = len + subreq->transferred; - stream0->sreq_max_len = subreq->len; - __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); __clear_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); subreq->retry_count++; - spin_lock_bh(&rreq->lock); - list_add_tail(&subreq->rreq_link, &rreq->subrequests); - subreq->prev_donated += rreq->prev_donated; - rreq->prev_donated = 0; trace_netfs_sreq(subreq, netfs_sreq_trace_retry); - spin_unlock_bh(&rreq->lock); - - BUG_ON(!len); /* Renegotiate max_len (rsize) */ + stream->sreq_max_len = subreq->len; if (rreq->netfs_ops->prepare_read && rreq->netfs_ops->prepare_read(subreq) < 0) { trace_netfs_sreq(subreq, netfs_sreq_trace_reprep_failed); __set_bit(NETFS_SREQ_FAILED, &subreq->flags); + goto abandon; } - part = umin(len, stream0->sreq_max_len); - if (unlikely(rreq->io_streams[0].sreq_max_segs)) - part = netfs_limit_iter(&source, 0, part, stream0->sreq_max_segs); + part = umin(len, stream->sreq_max_len); + if (unlikely(stream->sreq_max_segs)) + part = netfs_limit_iter(&source, 0, part, stream->sreq_max_segs); subreq->len = subreq->transferred + part; subreq->io_iter = source; iov_iter_truncate(&subreq->io_iter, part); @@ -170,57 +151,105 @@ static void netfs_retry_read_subrequests(struct netfs_io_request *rreq) if (!len) { if (boundary) __set_bit(NETFS_SREQ_BOUNDARY, &subreq->flags); - subreq->next_donated = deferred_next_donated; } else { __clear_bit(NETFS_SREQ_BOUNDARY, &subreq->flags); - subreq->next_donated = 0; } + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); netfs_reissue_read(rreq, subreq); - if (!len) + if (subreq == to) { + subreq_superfluous = false; break; - - /* If we ran out of subrequests, allocate another. */ - if (list_empty(&sublist)) { - subreq = netfs_alloc_subrequest(rreq); - if (!subreq) - goto abandon; - subreq->source = NETFS_DOWNLOAD_FROM_SERVER; - subreq->start = start; - - /* We get two refs, but need just one. */ - netfs_put_subrequest(subreq, false, netfs_sreq_trace_new); - trace_netfs_sreq(subreq, netfs_sreq_trace_split); - list_add_tail(&subreq->rreq_link, &sublist); } } /* If we managed to use fewer subreqs, we can discard the - * excess. + * excess; if we used the same number, then we're done. */ - while ((subreq = list_first_entry_or_null( - &sublist, struct netfs_io_subrequest, rreq_link))) { - trace_netfs_sreq(subreq, netfs_sreq_trace_discard); - list_del(&subreq->rreq_link); - netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done); + if (!len) { + if (!subreq_superfluous) + continue; + list_for_each_entry_safe_from(subreq, tmp, + &stream->subrequests, rreq_link) { + trace_netfs_sreq(subreq, netfs_sreq_trace_superfluous); + list_del(&subreq->rreq_link); + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done); + if (subreq == to) + break; + } + continue; } - } while (!list_empty(&queue)); + /* We ran out of subrequests, so we need to allocate some more + * and insert them after. + */ + do { + subreq = netfs_alloc_subrequest(rreq); + if (!subreq) { + subreq = to; + goto abandon_after; + } + subreq->source = NETFS_DOWNLOAD_FROM_SERVER; + subreq->start = start; + subreq->len = len; + subreq->stream_nr = stream->stream_nr; + subreq->retry_count = 1; + + trace_netfs_sreq_ref(rreq->debug_id, subreq->debug_index, + refcount_read(&subreq->ref), + netfs_sreq_trace_new); + + list_add(&subreq->rreq_link, &to->rreq_link); + to = list_next_entry(to, rreq_link); + trace_netfs_sreq(subreq, netfs_sreq_trace_retry); + + stream->sreq_max_len = umin(len, rreq->rsize); + stream->sreq_max_segs = 0; + if (unlikely(stream->sreq_max_segs)) + part = netfs_limit_iter(&source, 0, part, stream->sreq_max_segs); + + netfs_stat(&netfs_n_rh_download); + if (rreq->netfs_ops->prepare_read(subreq) < 0) { + trace_netfs_sreq(subreq, netfs_sreq_trace_reprep_failed); + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); + goto abandon; + } + + part = umin(len, stream->sreq_max_len); + subreq->len = subreq->transferred + part; + subreq->io_iter = source; + iov_iter_truncate(&subreq->io_iter, part); + iov_iter_advance(&source, part); + + len -= part; + start += part; + if (!len && boundary) { + __set_bit(NETFS_SREQ_BOUNDARY, &to->flags); + boundary = false; + } + + netfs_reissue_read(rreq, subreq); + } while (len); + + } while (!list_is_head(next, &stream->subrequests)); return; - /* If we hit ENOMEM, fail all remaining subrequests */ + /* If we hit an error, fail all remaining incomplete subrequests */ +abandon_after: + if (list_is_last(&subreq->rreq_link, &stream->subrequests)) + return; + subreq = list_next_entry(subreq, rreq_link); abandon: - list_splice_init(&sublist, &queue); - list_for_each_entry(subreq, &queue, rreq_link) { - if (!subreq->error) - subreq->error = -ENOMEM; - __clear_bit(NETFS_SREQ_FAILED, &subreq->flags); + list_for_each_entry_from(subreq, &stream->subrequests, rreq_link) { + if (!subreq->error && + !test_bit(NETFS_SREQ_FAILED, &subreq->flags) && + !test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) + continue; + subreq->error = -ENOMEM; + __set_bit(NETFS_SREQ_FAILED, &subreq->flags); __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); } - spin_lock_bh(&rreq->lock); - list_splice_tail_init(&queue, &rreq->subrequests); - spin_unlock_bh(&rreq->lock); } /* @@ -228,14 +257,39 @@ abandon: */ void netfs_retry_reads(struct netfs_io_request *rreq) { - trace_netfs_rreq(rreq, netfs_rreq_trace_resubmit); + struct netfs_io_subrequest *subreq; + struct netfs_io_stream *stream = &rreq->io_streams[0]; + DEFINE_WAIT(myself); - atomic_inc(&rreq->nr_outstanding); + netfs_stat(&netfs_n_rh_retry_read_req); - netfs_retry_read_subrequests(rreq); + set_bit(NETFS_RREQ_RETRYING, &rreq->flags); + + /* Wait for all outstanding I/O to quiesce before performing retries as + * we may need to renegotiate the I/O sizes. + */ + list_for_each_entry(subreq, &stream->subrequests, rreq_link) { + if (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags)) + continue; + + trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue); + for (;;) { + prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE); + + if (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags)) + break; - if (atomic_dec_and_test(&rreq->nr_outstanding)) - netfs_rreq_terminated(rreq, false); + trace_netfs_sreq(subreq, netfs_sreq_trace_wait_for); + schedule(); + trace_netfs_rreq(rreq, netfs_rreq_trace_woke_queue); + } + + finish_wait(&rreq->waitq, &myself); + } + clear_bit(NETFS_RREQ_RETRYING, &rreq->flags); + + trace_netfs_rreq(rreq, netfs_rreq_trace_resubmit); + netfs_retry_read_subrequests(rreq); } /* @@ -246,7 +300,7 @@ void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq) { struct folio_queue *p; - for (p = rreq->buffer; p; p = p->next) { + for (p = rreq->buffer.tail; p; p = p->next) { for (int slot = 0; slot < folioq_count(p); slot++) { struct folio *folio = folioq_folio(p, slot); diff --git a/fs/netfs/read_single.c b/fs/netfs/read_single.c new file mode 100644 index 000000000000..fea0ecdecc53 --- /dev/null +++ b/fs/netfs/read_single.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Single, monolithic object support (e.g. AFS directory). + * + * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include <linux/uio.h> +#include <linux/sched/mm.h> +#include <linux/task_io_accounting_ops.h> +#include <linux/netfs.h> +#include "internal.h" + +/** + * netfs_single_mark_inode_dirty - Mark a single, monolithic object inode dirty + * @inode: The inode to mark + * + * Mark an inode that contains a single, monolithic object as dirty so that its + * writepages op will get called. If set, the SINGLE_NO_UPLOAD flag indicates + * that the object will only be written to the cache and not uploaded (e.g. AFS + * directory contents). + */ +void netfs_single_mark_inode_dirty(struct inode *inode) +{ + struct netfs_inode *ictx = netfs_inode(inode); + bool cache_only = test_bit(NETFS_ICTX_SINGLE_NO_UPLOAD, &ictx->flags); + bool caching = fscache_cookie_enabled(netfs_i_cookie(netfs_inode(inode))); + + if (cache_only && !caching) + return; + + mark_inode_dirty(inode); + + if (caching && !(inode->i_state & I_PINNING_NETFS_WB)) { + bool need_use = false; + + spin_lock(&inode->i_lock); + if (!(inode->i_state & I_PINNING_NETFS_WB)) { + inode->i_state |= I_PINNING_NETFS_WB; + need_use = true; + } + spin_unlock(&inode->i_lock); + + if (need_use) + fscache_use_cookie(netfs_i_cookie(ictx), true); + } + +} +EXPORT_SYMBOL(netfs_single_mark_inode_dirty); + +static int netfs_single_begin_cache_read(struct netfs_io_request *rreq, struct netfs_inode *ctx) +{ + return fscache_begin_read_operation(&rreq->cache_resources, netfs_i_cookie(ctx)); +} + +static void netfs_single_cache_prepare_read(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq) +{ + struct netfs_cache_resources *cres = &rreq->cache_resources; + + if (!cres->ops) { + subreq->source = NETFS_DOWNLOAD_FROM_SERVER; + return; + } + subreq->source = cres->ops->prepare_read(subreq, rreq->i_size); + trace_netfs_sreq(subreq, netfs_sreq_trace_prepare); + +} + +static void netfs_single_read_cache(struct netfs_io_request *rreq, + struct netfs_io_subrequest *subreq) +{ + struct netfs_cache_resources *cres = &rreq->cache_resources; + + _enter("R=%08x[%x]", rreq->debug_id, subreq->debug_index); + netfs_stat(&netfs_n_rh_read); + cres->ops->read(cres, subreq->start, &subreq->io_iter, NETFS_READ_HOLE_FAIL, + netfs_cache_read_terminated, subreq); +} + +/* + * Perform a read to a buffer from the cache or the server. Only a single + * subreq is permitted as the object must be fetched in a single transaction. + */ +static int netfs_single_dispatch_read(struct netfs_io_request *rreq) +{ + struct netfs_io_stream *stream = &rreq->io_streams[0]; + struct netfs_io_subrequest *subreq; + int ret = 0; + + subreq = netfs_alloc_subrequest(rreq); + if (!subreq) + return -ENOMEM; + + subreq->source = NETFS_SOURCE_UNKNOWN; + subreq->start = 0; + subreq->len = rreq->len; + subreq->io_iter = rreq->buffer.iter; + + __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); + + spin_lock(&rreq->lock); + list_add_tail(&subreq->rreq_link, &stream->subrequests); + trace_netfs_sreq(subreq, netfs_sreq_trace_added); + stream->front = subreq; + /* Store list pointers before active flag */ + smp_store_release(&stream->active, true); + spin_unlock(&rreq->lock); + + netfs_single_cache_prepare_read(rreq, subreq); + switch (subreq->source) { + case NETFS_DOWNLOAD_FROM_SERVER: + netfs_stat(&netfs_n_rh_download); + if (rreq->netfs_ops->prepare_read) { + ret = rreq->netfs_ops->prepare_read(subreq); + if (ret < 0) + goto cancel; + } + + rreq->netfs_ops->issue_read(subreq); + rreq->submitted += subreq->len; + break; + case NETFS_READ_FROM_CACHE: + trace_netfs_sreq(subreq, netfs_sreq_trace_submit); + netfs_single_read_cache(rreq, subreq); + rreq->submitted += subreq->len; + ret = 0; + break; + default: + pr_warn("Unexpected single-read source %u\n", subreq->source); + WARN_ON_ONCE(true); + ret = -EIO; + break; + } + + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags); + return ret; +cancel: + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_cancel); + return ret; +} + +/** + * netfs_read_single - Synchronously read a single blob of pages. + * @inode: The inode to read from. + * @file: The file we're using to read or NULL. + * @iter: The buffer we're reading into. + * + * Fulfil a read request for a single monolithic object by drawing data from + * the cache if possible, or the netfs if not. The buffer may be larger than + * the file content; unused beyond the EOF will be zero-filled. The content + * will be read with a single I/O request (though this may be retried). + * + * The calling netfs must initialise a netfs context contiguous to the vfs + * inode before calling this. + * + * This is usable whether or not caching is enabled. If caching is enabled, + * the data will be stored as a single object into the cache. + */ +ssize_t netfs_read_single(struct inode *inode, struct file *file, struct iov_iter *iter) +{ + struct netfs_io_request *rreq; + struct netfs_inode *ictx = netfs_inode(inode); + ssize_t ret; + + rreq = netfs_alloc_request(inode->i_mapping, file, 0, iov_iter_count(iter), + NETFS_READ_SINGLE); + if (IS_ERR(rreq)) + return PTR_ERR(rreq); + + ret = netfs_single_begin_cache_read(rreq, ictx); + if (ret == -ENOMEM || ret == -EINTR || ret == -ERESTARTSYS) + goto cleanup_free; + + netfs_stat(&netfs_n_rh_read_single); + trace_netfs_read(rreq, 0, rreq->len, netfs_read_trace_read_single); + + rreq->buffer.iter = *iter; + netfs_single_dispatch_read(rreq); + + ret = netfs_wait_for_read(rreq); + netfs_put_request(rreq, true, netfs_rreq_trace_put_return); + return ret; + +cleanup_free: + netfs_put_request(rreq, false, netfs_rreq_trace_put_failed); + return ret; +} +EXPORT_SYMBOL(netfs_read_single); diff --git a/fs/netfs/rolling_buffer.c b/fs/netfs/rolling_buffer.c new file mode 100644 index 000000000000..207b6a326651 --- /dev/null +++ b/fs/netfs/rolling_buffer.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Rolling buffer helpers + * + * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/bitops.h> +#include <linux/pagemap.h> +#include <linux/rolling_buffer.h> +#include <linux/slab.h> +#include "internal.h" + +static atomic_t debug_ids; + +/** + * netfs_folioq_alloc - Allocate a folio_queue struct + * @rreq_id: Associated debugging ID for tracing purposes + * @gfp: Allocation constraints + * @trace: Trace tag to indicate the purpose of the allocation + * + * Allocate, initialise and account the folio_queue struct and log a trace line + * to mark the allocation. + */ +struct folio_queue *netfs_folioq_alloc(unsigned int rreq_id, gfp_t gfp, + unsigned int /*enum netfs_folioq_trace*/ trace) +{ + struct folio_queue *fq; + + fq = kmalloc(sizeof(*fq), gfp); + if (fq) { + netfs_stat(&netfs_n_folioq); + folioq_init(fq, rreq_id); + fq->debug_id = atomic_inc_return(&debug_ids); + trace_netfs_folioq(fq, trace); + } + return fq; +} +EXPORT_SYMBOL(netfs_folioq_alloc); + +/** + * netfs_folioq_free - Free a folio_queue struct + * @folioq: The object to free + * @trace: Trace tag to indicate which free + * + * Free and unaccount the folio_queue struct. + */ +void netfs_folioq_free(struct folio_queue *folioq, + unsigned int /*enum netfs_trace_folioq*/ trace) +{ + trace_netfs_folioq(folioq, trace); + netfs_stat_d(&netfs_n_folioq); + kfree(folioq); +} +EXPORT_SYMBOL(netfs_folioq_free); + +/* + * Initialise a rolling buffer. We allocate an empty folio queue struct to so + * that the pointers can be independently driven by the producer and the + * consumer. + */ +int rolling_buffer_init(struct rolling_buffer *roll, unsigned int rreq_id, + unsigned int direction) +{ + struct folio_queue *fq; + + fq = netfs_folioq_alloc(rreq_id, GFP_NOFS, netfs_trace_folioq_rollbuf_init); + if (!fq) + return -ENOMEM; + + roll->head = fq; + roll->tail = fq; + iov_iter_folio_queue(&roll->iter, direction, fq, 0, 0, 0); + return 0; +} + +/* + * Add another folio_queue to a rolling buffer if there's no space left. + */ +int rolling_buffer_make_space(struct rolling_buffer *roll) +{ + struct folio_queue *fq, *head = roll->head; + + if (!folioq_full(head)) + return 0; + + fq = netfs_folioq_alloc(head->rreq_id, GFP_NOFS, netfs_trace_folioq_make_space); + if (!fq) + return -ENOMEM; + fq->prev = head; + + roll->head = fq; + if (folioq_full(head)) { + /* Make sure we don't leave the master iterator pointing to a + * block that might get immediately consumed. + */ + if (roll->iter.folioq == head && + roll->iter.folioq_slot == folioq_nr_slots(head)) { + roll->iter.folioq = fq; + roll->iter.folioq_slot = 0; + } + } + + /* Make sure the initialisation is stored before the next pointer. + * + * [!] NOTE: After we set head->next, the consumer is at liberty to + * immediately delete the old head. + */ + smp_store_release(&head->next, fq); + return 0; +} + +/* + * Decant the list of folios to read into a rolling buffer. + */ +ssize_t rolling_buffer_load_from_ra(struct rolling_buffer *roll, + struct readahead_control *ractl, + struct folio_batch *put_batch) +{ + struct folio_queue *fq; + struct page **vec; + int nr, ix, to; + ssize_t size = 0; + + if (rolling_buffer_make_space(roll) < 0) + return -ENOMEM; + + fq = roll->head; + vec = (struct page **)fq->vec.folios; + nr = __readahead_batch(ractl, vec + folio_batch_count(&fq->vec), + folio_batch_space(&fq->vec)); + ix = fq->vec.nr; + to = ix + nr; + fq->vec.nr = to; + for (; ix < to; ix++) { + struct folio *folio = folioq_folio(fq, ix); + unsigned int order = folio_order(folio); + + fq->orders[ix] = order; + size += PAGE_SIZE << order; + trace_netfs_folio(folio, netfs_folio_trace_read); + if (!folio_batch_add(put_batch, folio)) + folio_batch_release(put_batch); + } + WRITE_ONCE(roll->iter.count, roll->iter.count + size); + + /* Store the counter after setting the slot. */ + smp_store_release(&roll->next_head_slot, to); + return size; +} + +/* + * Append a folio to the rolling buffer. + */ +ssize_t rolling_buffer_append(struct rolling_buffer *roll, struct folio *folio, + unsigned int flags) +{ + ssize_t size = folio_size(folio); + int slot; + + if (rolling_buffer_make_space(roll) < 0) + return -ENOMEM; + + slot = folioq_append(roll->head, folio); + if (flags & ROLLBUF_MARK_1) + folioq_mark(roll->head, slot); + if (flags & ROLLBUF_MARK_2) + folioq_mark2(roll->head, slot); + + WRITE_ONCE(roll->iter.count, roll->iter.count + size); + + /* Store the counter after setting the slot. */ + smp_store_release(&roll->next_head_slot, slot); + return size; +} + +/* + * Delete a spent buffer from a rolling queue and return the next in line. We + * don't return the last buffer to keep the pointers independent, but return + * NULL instead. + */ +struct folio_queue *rolling_buffer_delete_spent(struct rolling_buffer *roll) +{ + struct folio_queue *spent = roll->tail, *next = READ_ONCE(spent->next); + + if (!next) + return NULL; + next->prev = NULL; + netfs_folioq_free(spent, netfs_trace_folioq_delete); + roll->tail = next; + return next; +} + +/* + * Clear out a rolling queue. Folios that have mark 1 set are put. + */ +void rolling_buffer_clear(struct rolling_buffer *roll) +{ + struct folio_batch fbatch; + struct folio_queue *p; + + folio_batch_init(&fbatch); + + while ((p = roll->tail)) { + roll->tail = p->next; + for (int slot = 0; slot < folioq_count(p); slot++) { + struct folio *folio = folioq_folio(p, slot); + + if (!folio) + continue; + if (folioq_is_marked(p, slot)) { + trace_netfs_folio(folio, netfs_folio_trace_put); + if (!folio_batch_add(&fbatch, folio)) + folio_batch_release(&fbatch); + } + } + + netfs_folioq_free(p, netfs_trace_folioq_clear); + } + + folio_batch_release(&fbatch); +} diff --git a/fs/netfs/stats.c b/fs/netfs/stats.c index 8e63516b40f6..ab6b916addc4 100644 --- a/fs/netfs/stats.c +++ b/fs/netfs/stats.c @@ -12,6 +12,7 @@ atomic_t netfs_n_rh_dio_read; atomic_t netfs_n_rh_readahead; atomic_t netfs_n_rh_read_folio; +atomic_t netfs_n_rh_read_single; atomic_t netfs_n_rh_rreq; atomic_t netfs_n_rh_sreq; atomic_t netfs_n_rh_download; @@ -28,6 +29,8 @@ atomic_t netfs_n_rh_write_begin; atomic_t netfs_n_rh_write_done; atomic_t netfs_n_rh_write_failed; atomic_t netfs_n_rh_write_zskip; +atomic_t netfs_n_rh_retry_read_req; +atomic_t netfs_n_rh_retry_read_subreq; atomic_t netfs_n_wh_buffered_write; atomic_t netfs_n_wh_writethrough; atomic_t netfs_n_wh_dio_write; @@ -40,16 +43,19 @@ atomic_t netfs_n_wh_upload_failed; atomic_t netfs_n_wh_write; atomic_t netfs_n_wh_write_done; atomic_t netfs_n_wh_write_failed; +atomic_t netfs_n_wh_retry_write_req; +atomic_t netfs_n_wh_retry_write_subreq; atomic_t netfs_n_wb_lock_skip; atomic_t netfs_n_wb_lock_wait; atomic_t netfs_n_folioq; int netfs_stats_show(struct seq_file *m, void *v) { - seq_printf(m, "Reads : DR=%u RA=%u RF=%u WB=%u WBZ=%u\n", + seq_printf(m, "Reads : DR=%u RA=%u RF=%u RS=%u WB=%u WBZ=%u\n", atomic_read(&netfs_n_rh_dio_read), atomic_read(&netfs_n_rh_readahead), atomic_read(&netfs_n_rh_read_folio), + atomic_read(&netfs_n_rh_read_single), atomic_read(&netfs_n_rh_write_begin), atomic_read(&netfs_n_rh_write_zskip)); seq_printf(m, "Writes : BW=%u WT=%u DW=%u WP=%u 2C=%u\n", @@ -79,6 +85,11 @@ int netfs_stats_show(struct seq_file *m, void *v) atomic_read(&netfs_n_wh_write), atomic_read(&netfs_n_wh_write_done), atomic_read(&netfs_n_wh_write_failed)); + seq_printf(m, "Retries: rq=%u rs=%u wq=%u ws=%u\n", + atomic_read(&netfs_n_rh_retry_read_req), + atomic_read(&netfs_n_rh_retry_read_subreq), + atomic_read(&netfs_n_wh_retry_write_req), + atomic_read(&netfs_n_wh_retry_write_subreq)); seq_printf(m, "Objs : rr=%u sr=%u foq=%u wsc=%u\n", atomic_read(&netfs_n_rh_rreq), atomic_read(&netfs_n_rh_sreq), diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c index ca3a11ed9b54..3fca59e6475d 100644 --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -17,10 +17,38 @@ #define HIT_PENDING 0x01 /* A front op was still pending */ #define NEED_REASSESS 0x02 /* Need to loop round and reassess */ #define MADE_PROGRESS 0x04 /* Made progress cleaning up a stream or the folio set */ -#define BUFFERED 0x08 /* The pagecache needs cleaning up */ +#define NEED_UNLOCK 0x08 /* The pagecache needs unlocking */ #define NEED_RETRY 0x10 /* A front op requests retrying */ #define SAW_FAILURE 0x20 /* One stream or hit a permanent failure */ +static void netfs_dump_request(const struct netfs_io_request *rreq) +{ + pr_err("Request R=%08x r=%d fl=%lx or=%x e=%ld\n", + rreq->debug_id, refcount_read(&rreq->ref), rreq->flags, + rreq->origin, rreq->error); + pr_err(" st=%llx tsl=%zx/%llx/%llx\n", + rreq->start, rreq->transferred, rreq->submitted, rreq->len); + pr_err(" cci=%llx/%llx/%llx\n", + rreq->cleaned_to, rreq->collected_to, atomic64_read(&rreq->issued_to)); + pr_err(" iw=%pSR\n", rreq->netfs_ops->issue_write); + for (int i = 0; i < NR_IO_STREAMS; i++) { + const struct netfs_io_subrequest *sreq; + const struct netfs_io_stream *s = &rreq->io_streams[i]; + + pr_err(" str[%x] s=%x e=%d acnf=%u,%u,%u,%u\n", + s->stream_nr, s->source, s->error, + s->avail, s->active, s->need_retry, s->failed); + pr_err(" str[%x] ct=%llx t=%zx\n", + s->stream_nr, s->collected_to, s->transferred); + list_for_each_entry(sreq, &s->subrequests, rreq_link) { + pr_err(" sreq[%x:%x] sc=%u s=%llx t=%zx/%zx r=%d f=%lx\n", + sreq->stream_nr, sreq->debug_index, sreq->source, + sreq->start, sreq->transferred, sreq->len, + refcount_read(&sreq->ref), sreq->flags); + } + } +} + /* * Successful completion of write of a folio to the server and/or cache. Note * that we are not allowed to lock the folio here on pain of deadlocking with @@ -83,9 +111,15 @@ end_wb: static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq, unsigned int *notes) { - struct folio_queue *folioq = wreq->buffer; + struct folio_queue *folioq = wreq->buffer.tail; unsigned long long collected_to = wreq->collected_to; - unsigned int slot = wreq->buffer_head_slot; + unsigned int slot = wreq->buffer.first_tail_slot; + + if (WARN_ON_ONCE(!folioq)) { + pr_err("[!] Writeback unlock found empty rolling buffer!\n"); + netfs_dump_request(wreq); + return; + } if (wreq->origin == NETFS_PGPRIV2_COPY_TO_CACHE) { if (netfs_pgpriv2_unlock_copied_folios(wreq)) @@ -94,7 +128,9 @@ static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq, } if (slot >= folioq_nr_slots(folioq)) { - folioq = netfs_delete_buffer_head(wreq); + folioq = rolling_buffer_delete_spent(&wreq->buffer); + if (!folioq) + return; slot = 0; } @@ -134,9 +170,9 @@ static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq, folioq_clear(folioq, slot); slot++; if (slot >= folioq_nr_slots(folioq)) { - if (READ_ONCE(wreq->buffer_tail) == folioq) - break; - folioq = netfs_delete_buffer_head(wreq); + folioq = rolling_buffer_delete_spent(&wreq->buffer); + if (!folioq) + goto done; slot = 0; } @@ -144,222 +180,9 @@ static void netfs_writeback_unlock_folios(struct netfs_io_request *wreq, break; } - wreq->buffer = folioq; - wreq->buffer_head_slot = slot; -} - -/* - * Perform retries on the streams that need it. - */ -static void netfs_retry_write_stream(struct netfs_io_request *wreq, - struct netfs_io_stream *stream) -{ - struct list_head *next; - - _enter("R=%x[%x:]", wreq->debug_id, stream->stream_nr); - - if (list_empty(&stream->subrequests)) - return; - - if (stream->source == NETFS_UPLOAD_TO_SERVER && - wreq->netfs_ops->retry_request) - wreq->netfs_ops->retry_request(wreq, stream); - - if (unlikely(stream->failed)) - return; - - /* If there's no renegotiation to do, just resend each failed subreq. */ - if (!stream->prepare_write) { - struct netfs_io_subrequest *subreq; - - list_for_each_entry(subreq, &stream->subrequests, rreq_link) { - if (test_bit(NETFS_SREQ_FAILED, &subreq->flags)) - break; - if (__test_and_clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) { - struct iov_iter source = subreq->io_iter; - - iov_iter_revert(&source, subreq->len - source.count); - netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); - netfs_reissue_write(stream, subreq, &source); - } - } - return; - } - - next = stream->subrequests.next; - - do { - struct netfs_io_subrequest *subreq = NULL, *from, *to, *tmp; - struct iov_iter source; - unsigned long long start, len; - size_t part; - bool boundary = false; - - /* Go through the stream and find the next span of contiguous - * data that we then rejig (cifs, for example, needs the wsize - * renegotiating) and reissue. - */ - from = list_entry(next, struct netfs_io_subrequest, rreq_link); - to = from; - start = from->start + from->transferred; - len = from->len - from->transferred; - - if (test_bit(NETFS_SREQ_FAILED, &from->flags) || - !test_bit(NETFS_SREQ_NEED_RETRY, &from->flags)) - return; - - list_for_each_continue(next, &stream->subrequests) { - subreq = list_entry(next, struct netfs_io_subrequest, rreq_link); - if (subreq->start + subreq->transferred != start + len || - test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) || - !test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) - break; - to = subreq; - len += to->len; - } - - /* Determine the set of buffers we're going to use. Each - * subreq gets a subset of a single overall contiguous buffer. - */ - netfs_reset_iter(from); - source = from->io_iter; - source.count = len; - - /* Work through the sublist. */ - subreq = from; - list_for_each_entry_from(subreq, &stream->subrequests, rreq_link) { - if (!len) - break; - /* Renegotiate max_len (wsize) */ - trace_netfs_sreq(subreq, netfs_sreq_trace_retry); - __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); - subreq->retry_count++; - stream->prepare_write(subreq); - - part = min(len, stream->sreq_max_len); - subreq->len = part; - subreq->start = start; - subreq->transferred = 0; - len -= part; - start += part; - if (len && subreq == to && - __test_and_clear_bit(NETFS_SREQ_BOUNDARY, &to->flags)) - boundary = true; - - netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); - netfs_reissue_write(stream, subreq, &source); - if (subreq == to) - break; - } - - /* If we managed to use fewer subreqs, we can discard the - * excess; if we used the same number, then we're done. - */ - if (!len) { - if (subreq == to) - continue; - list_for_each_entry_safe_from(subreq, tmp, - &stream->subrequests, rreq_link) { - trace_netfs_sreq(subreq, netfs_sreq_trace_discard); - list_del(&subreq->rreq_link); - netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done); - if (subreq == to) - break; - } - continue; - } - - /* We ran out of subrequests, so we need to allocate some more - * and insert them after. - */ - do { - subreq = netfs_alloc_subrequest(wreq); - subreq->source = to->source; - subreq->start = start; - subreq->debug_index = atomic_inc_return(&wreq->subreq_counter); - subreq->stream_nr = to->stream_nr; - subreq->retry_count = 1; - - trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index, - refcount_read(&subreq->ref), - netfs_sreq_trace_new); - netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); - - list_add(&subreq->rreq_link, &to->rreq_link); - to = list_next_entry(to, rreq_link); - trace_netfs_sreq(subreq, netfs_sreq_trace_retry); - - stream->sreq_max_len = len; - stream->sreq_max_segs = INT_MAX; - switch (stream->source) { - case NETFS_UPLOAD_TO_SERVER: - netfs_stat(&netfs_n_wh_upload); - stream->sreq_max_len = umin(len, wreq->wsize); - break; - case NETFS_WRITE_TO_CACHE: - netfs_stat(&netfs_n_wh_write); - break; - default: - WARN_ON_ONCE(1); - } - - stream->prepare_write(subreq); - - part = umin(len, stream->sreq_max_len); - subreq->len = subreq->transferred + part; - len -= part; - start += part; - if (!len && boundary) { - __set_bit(NETFS_SREQ_BOUNDARY, &to->flags); - boundary = false; - } - - netfs_reissue_write(stream, subreq, &source); - if (!len) - break; - - } while (len); - - } while (!list_is_head(next, &stream->subrequests)); -} - -/* - * Perform retries on the streams that need it. If we're doing content - * encryption and the server copy changed due to a third-party write, we may - * need to do an RMW cycle and also rewrite the data to the cache. - */ -static void netfs_retry_writes(struct netfs_io_request *wreq) -{ - struct netfs_io_subrequest *subreq; - struct netfs_io_stream *stream; - int s; - - /* Wait for all outstanding I/O to quiesce before performing retries as - * we may need to renegotiate the I/O sizes. - */ - for (s = 0; s < NR_IO_STREAMS; s++) { - stream = &wreq->io_streams[s]; - if (!stream->active) - continue; - - list_for_each_entry(subreq, &stream->subrequests, rreq_link) { - wait_on_bit(&subreq->flags, NETFS_SREQ_IN_PROGRESS, - TASK_UNINTERRUPTIBLE); - } - } - - // TODO: Enc: Fetch changed partial pages - // TODO: Enc: Reencrypt content if needed. - // TODO: Enc: Wind back transferred point. - // TODO: Enc: Mark cache pages for retry. - - for (s = 0; s < NR_IO_STREAMS; s++) { - stream = &wreq->io_streams[s]; - if (stream->need_retry) { - stream->need_retry = false; - netfs_retry_write_stream(wreq, stream); - } - } + wreq->buffer.tail = folioq; +done: + wreq->buffer.first_tail_slot = slot; } /* @@ -390,7 +213,7 @@ reassess_streams: if (wreq->origin == NETFS_WRITEBACK || wreq->origin == NETFS_WRITETHROUGH || wreq->origin == NETFS_PGPRIV2_COPY_TO_CACHE) - notes = BUFFERED; + notes = NEED_UNLOCK; else notes = 0; @@ -449,14 +272,14 @@ reassess_streams: cancel: /* Remove if completely consumed. */ - spin_lock_bh(&wreq->lock); + spin_lock(&wreq->lock); remove = front; list_del_init(&front->rreq_link); front = list_first_entry_or_null(&stream->subrequests, struct netfs_io_subrequest, rreq_link); stream->front = front; - spin_unlock_bh(&wreq->lock); + spin_unlock(&wreq->lock); netfs_put_subrequest(remove, false, notes & SAW_FAILURE ? netfs_sreq_trace_put_cancel : @@ -487,7 +310,7 @@ reassess_streams: trace_netfs_collect_state(wreq, wreq->collected_to, notes); /* Unlock any folios that we have now finished with. */ - if (notes & BUFFERED) { + if (notes & NEED_UNLOCK) { if (wreq->cleaned_to < wreq->collected_to) netfs_writeback_unlock_folios(wreq, ¬es); } else { @@ -500,7 +323,9 @@ reassess_streams: goto need_retry; if ((notes & MADE_PROGRESS) && test_bit(NETFS_RREQ_PAUSE, &wreq->flags)) { trace_netfs_rreq(wreq, netfs_rreq_trace_unpause); - clear_and_wake_up_bit(NETFS_RREQ_PAUSE, &wreq->flags); + clear_bit_unlock(NETFS_RREQ_PAUSE, &wreq->flags); + smp_mb__after_atomic(); /* Set PAUSE before task state */ + wake_up(&wreq->waitq); } if (notes & NEED_REASSESS) { @@ -575,7 +400,8 @@ void netfs_write_collection_worker(struct work_struct *work) trace_netfs_rreq(wreq, netfs_rreq_trace_write_done); if (wreq->io_streams[1].active && - wreq->io_streams[1].failed) { + wreq->io_streams[1].failed && + ictx->ops->invalidate_cache) { /* Cache write failure doesn't prevent writeback completion * unless we're in disconnected mode. */ diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index ff0e82505a0b..77279fc5b5a7 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -94,9 +94,10 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping, { struct netfs_io_request *wreq; struct netfs_inode *ictx; - bool is_buffered = (origin == NETFS_WRITEBACK || - origin == NETFS_WRITETHROUGH || - origin == NETFS_PGPRIV2_COPY_TO_CACHE); + bool is_cacheable = (origin == NETFS_WRITEBACK || + origin == NETFS_WRITEBACK_SINGLE || + origin == NETFS_WRITETHROUGH || + origin == NETFS_PGPRIV2_COPY_TO_CACHE); wreq = netfs_alloc_request(mapping, file, start, 0, origin); if (IS_ERR(wreq)) @@ -105,8 +106,10 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping, _enter("R=%x", wreq->debug_id); ictx = netfs_inode(wreq->inode); - if (is_buffered && netfs_is_cache_enabled(ictx)) + if (is_cacheable && netfs_is_cache_enabled(ictx)) fscache_begin_write_operation(&wreq->cache_resources, netfs_i_cookie(ictx)); + if (rolling_buffer_init(&wreq->buffer, wreq->debug_id, ITER_SOURCE) < 0) + goto nomem; wreq->cleaned_to = wreq->start; @@ -129,6 +132,10 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping, } return wreq; +nomem: + wreq->error = -ENOMEM; + netfs_put_request(wreq, false, netfs_rreq_trace_put_failed); + return ERR_PTR(-ENOMEM); } /** @@ -153,16 +160,15 @@ static void netfs_prepare_write(struct netfs_io_request *wreq, loff_t start) { struct netfs_io_subrequest *subreq; - struct iov_iter *wreq_iter = &wreq->io_iter; + struct iov_iter *wreq_iter = &wreq->buffer.iter; /* Make sure we don't point the iterator at a used-up folio_queue * struct being used as a placeholder to prevent the queue from * collapsing. In such a case, extend the queue. */ if (iov_iter_is_folioq(wreq_iter) && - wreq_iter->folioq_slot >= folioq_nr_slots(wreq_iter->folioq)) { - netfs_buffer_make_space(wreq); - } + wreq_iter->folioq_slot >= folioq_nr_slots(wreq_iter->folioq)) + rolling_buffer_make_space(&wreq->buffer); subreq = netfs_alloc_subrequest(wreq); subreq->source = stream->source; @@ -198,7 +204,7 @@ static void netfs_prepare_write(struct netfs_io_request *wreq, * the list. The collector only goes nextwards and uses the lock to * remove entries off of the front. */ - spin_lock_bh(&wreq->lock); + spin_lock(&wreq->lock); list_add_tail(&subreq->rreq_link, &stream->subrequests); if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { stream->front = subreq; @@ -209,7 +215,7 @@ static void netfs_prepare_write(struct netfs_io_request *wreq, } } - spin_unlock_bh(&wreq->lock); + spin_unlock(&wreq->lock); stream->construct = subreq; } @@ -247,6 +253,7 @@ void netfs_reissue_write(struct netfs_io_stream *stream, subreq->retry_count++; __clear_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); __set_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags); + netfs_stat(&netfs_n_wh_retry_write_subreq); netfs_do_issue_write(stream, subreq); } @@ -268,9 +275,9 @@ void netfs_issue_write(struct netfs_io_request *wreq, * we can avoid overrunning the credits obtained (cifs) and try to parallelise * content-crypto preparation with network writes. */ -int netfs_advance_write(struct netfs_io_request *wreq, - struct netfs_io_stream *stream, - loff_t start, size_t len, bool to_eof) +size_t netfs_advance_write(struct netfs_io_request *wreq, + struct netfs_io_stream *stream, + loff_t start, size_t len, bool to_eof) { struct netfs_io_subrequest *subreq = stream->construct; size_t part; @@ -327,6 +334,9 @@ static int netfs_write_folio(struct netfs_io_request *wreq, _enter(""); + if (rolling_buffer_make_space(&wreq->buffer) < 0) + return -ENOMEM; + /* netfs_perform_write() may shift i_size around the page or from out * of the page to beyond it, but cannot move i_size into or through the * page since we have it locked. @@ -431,7 +441,7 @@ static int netfs_write_folio(struct netfs_io_request *wreq, } /* Attach the folio to the rolling buffer. */ - netfs_buffer_append_folio(wreq, folio, false); + rolling_buffer_append(&wreq->buffer, folio, 0); /* Move the submission point forward to allow for write-streaming data * not starting at the front of the page. We don't do write-streaming @@ -444,7 +454,8 @@ static int netfs_write_folio(struct netfs_io_request *wreq, stream = &wreq->io_streams[s]; stream->submit_off = foff; stream->submit_len = flen; - if ((stream->source == NETFS_WRITE_TO_CACHE && streamw) || + if (!stream->avail || + (stream->source == NETFS_WRITE_TO_CACHE && streamw) || (stream->source == NETFS_UPLOAD_TO_SERVER && fgroup == NETFS_FOLIO_COPY_TO_CACHE)) { stream->submit_off = UINT_MAX; @@ -478,7 +489,7 @@ static int netfs_write_folio(struct netfs_io_request *wreq, /* Advance the iterator(s). */ if (stream->submit_off > iter_off) { - iov_iter_advance(&wreq->io_iter, stream->submit_off - iter_off); + rolling_buffer_advance(&wreq->buffer, stream->submit_off - iter_off); iter_off = stream->submit_off; } @@ -496,7 +507,7 @@ static int netfs_write_folio(struct netfs_io_request *wreq, } if (fsize > iter_off) - iov_iter_advance(&wreq->io_iter, fsize - iter_off); + rolling_buffer_advance(&wreq->buffer, fsize - iter_off); atomic64_set(&wreq->issued_to, fpos + fsize); if (!debug) @@ -635,7 +646,7 @@ int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_c struct folio **writethrough_cache) { _enter("R=%x ic=%zu ws=%u cp=%zu tp=%u", - wreq->debug_id, wreq->iter.count, wreq->wsize, copied, to_page_end); + wreq->debug_id, wreq->buffer.iter.count, wreq->wsize, copied, to_page_end); if (!*writethrough_cache) { if (folio_test_dirty(folio)) @@ -710,10 +721,10 @@ int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t part = netfs_advance_write(wreq, upload, start, len, false); start += part; len -= part; - iov_iter_advance(&wreq->io_iter, part); + rolling_buffer_advance(&wreq->buffer, part); if (test_bit(NETFS_RREQ_PAUSE, &wreq->flags)) { trace_netfs_rreq(wreq, netfs_rreq_trace_wait_pause); - wait_on_bit(&wreq->flags, NETFS_RREQ_PAUSE, TASK_UNINTERRUPTIBLE); + wait_event(wreq->waitq, !test_bit(NETFS_RREQ_PAUSE, &wreq->flags)); } if (test_bit(NETFS_RREQ_FAILED, &wreq->flags)) break; @@ -723,3 +734,194 @@ int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t _leave(" = %d", error); return error; } + +/* + * Write some of a pending folio data back to the server and/or the cache. + */ +static int netfs_write_folio_single(struct netfs_io_request *wreq, + struct folio *folio) +{ + struct netfs_io_stream *upload = &wreq->io_streams[0]; + struct netfs_io_stream *cache = &wreq->io_streams[1]; + struct netfs_io_stream *stream; + size_t iter_off = 0; + size_t fsize = folio_size(folio), flen; + loff_t fpos = folio_pos(folio); + bool to_eof = false; + bool no_debug = false; + + _enter(""); + + flen = folio_size(folio); + if (flen > wreq->i_size - fpos) { + flen = wreq->i_size - fpos; + folio_zero_segment(folio, flen, fsize); + to_eof = true; + } else if (flen == wreq->i_size - fpos) { + to_eof = true; + } + + _debug("folio %zx/%zx", flen, fsize); + + if (!upload->avail && !cache->avail) { + trace_netfs_folio(folio, netfs_folio_trace_cancel_store); + return 0; + } + + if (!upload->construct) + trace_netfs_folio(folio, netfs_folio_trace_store); + else + trace_netfs_folio(folio, netfs_folio_trace_store_plus); + + /* Attach the folio to the rolling buffer. */ + folio_get(folio); + rolling_buffer_append(&wreq->buffer, folio, NETFS_ROLLBUF_PUT_MARK); + + /* Move the submission point forward to allow for write-streaming data + * not starting at the front of the page. We don't do write-streaming + * with the cache as the cache requires DIO alignment. + * + * Also skip uploading for data that's been read and just needs copying + * to the cache. + */ + for (int s = 0; s < NR_IO_STREAMS; s++) { + stream = &wreq->io_streams[s]; + stream->submit_off = 0; + stream->submit_len = flen; + if (!stream->avail) { + stream->submit_off = UINT_MAX; + stream->submit_len = 0; + } + } + + /* Attach the folio to one or more subrequests. For a big folio, we + * could end up with thousands of subrequests if the wsize is small - + * but we might need to wait during the creation of subrequests for + * network resources (eg. SMB credits). + */ + for (;;) { + ssize_t part; + size_t lowest_off = ULONG_MAX; + int choose_s = -1; + + /* Always add to the lowest-submitted stream first. */ + for (int s = 0; s < NR_IO_STREAMS; s++) { + stream = &wreq->io_streams[s]; + if (stream->submit_len > 0 && + stream->submit_off < lowest_off) { + lowest_off = stream->submit_off; + choose_s = s; + } + } + + if (choose_s < 0) + break; + stream = &wreq->io_streams[choose_s]; + + /* Advance the iterator(s). */ + if (stream->submit_off > iter_off) { + rolling_buffer_advance(&wreq->buffer, stream->submit_off - iter_off); + iter_off = stream->submit_off; + } + + atomic64_set(&wreq->issued_to, fpos + stream->submit_off); + stream->submit_extendable_to = fsize - stream->submit_off; + part = netfs_advance_write(wreq, stream, fpos + stream->submit_off, + stream->submit_len, to_eof); + stream->submit_off += part; + if (part > stream->submit_len) + stream->submit_len = 0; + else + stream->submit_len -= part; + if (part > 0) + no_debug = true; + } + + wreq->buffer.iter.iov_offset = 0; + if (fsize > iter_off) + rolling_buffer_advance(&wreq->buffer, fsize - iter_off); + atomic64_set(&wreq->issued_to, fpos + fsize); + + if (!no_debug) + kdebug("R=%x: No submit", wreq->debug_id); + _leave(" = 0"); + return 0; +} + +/** + * netfs_writeback_single - Write back a monolithic payload + * @mapping: The mapping to write from + * @wbc: Hints from the VM + * @iter: Data to write, must be ITER_FOLIOQ. + * + * Write a monolithic, non-pagecache object back to the server and/or + * the cache. + */ +int netfs_writeback_single(struct address_space *mapping, + struct writeback_control *wbc, + struct iov_iter *iter) +{ + struct netfs_io_request *wreq; + struct netfs_inode *ictx = netfs_inode(mapping->host); + struct folio_queue *fq; + size_t size = iov_iter_count(iter); + int ret; + + if (WARN_ON_ONCE(!iov_iter_is_folioq(iter))) + return -EIO; + + if (!mutex_trylock(&ictx->wb_lock)) { + if (wbc->sync_mode == WB_SYNC_NONE) { + netfs_stat(&netfs_n_wb_lock_skip); + return 0; + } + netfs_stat(&netfs_n_wb_lock_wait); + mutex_lock(&ictx->wb_lock); + } + + wreq = netfs_create_write_req(mapping, NULL, 0, NETFS_WRITEBACK_SINGLE); + if (IS_ERR(wreq)) { + ret = PTR_ERR(wreq); + goto couldnt_start; + } + + trace_netfs_write(wreq, netfs_write_trace_writeback); + netfs_stat(&netfs_n_wh_writepages); + + if (__test_and_set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags)) + wreq->netfs_ops->begin_writeback(wreq); + + for (fq = (struct folio_queue *)iter->folioq; fq; fq = fq->next) { + for (int slot = 0; slot < folioq_count(fq); slot++) { + struct folio *folio = folioq_folio(fq, slot); + size_t part = umin(folioq_folio_size(fq, slot), size); + + _debug("wbiter %lx %llx", folio->index, atomic64_read(&wreq->issued_to)); + + ret = netfs_write_folio_single(wreq, folio); + if (ret < 0) + goto stop; + size -= part; + if (size <= 0) + goto stop; + } + } + +stop: + for (int s = 0; s < NR_IO_STREAMS; s++) + netfs_issue_write(wreq, &wreq->io_streams[s]); + smp_wmb(); /* Write lists before ALL_QUEUED. */ + set_bit(NETFS_RREQ_ALL_QUEUED, &wreq->flags); + + mutex_unlock(&ictx->wb_lock); + + netfs_put_request(wreq, false, netfs_rreq_trace_put_return); + _leave(" = %d", ret); + return ret; + +couldnt_start: + mutex_unlock(&ictx->wb_lock); + _leave(" = %d", ret); + return ret; +} +EXPORT_SYMBOL(netfs_writeback_single); diff --git a/fs/netfs/write_retry.c b/fs/netfs/write_retry.c new file mode 100644 index 000000000000..545d33079a77 --- /dev/null +++ b/fs/netfs/write_retry.c @@ -0,0 +1,234 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Network filesystem write retrying. + * + * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/pagemap.h> +#include <linux/slab.h> +#include "internal.h" + +/* + * Perform retries on the streams that need it. + */ +static void netfs_retry_write_stream(struct netfs_io_request *wreq, + struct netfs_io_stream *stream) +{ + struct list_head *next; + + _enter("R=%x[%x:]", wreq->debug_id, stream->stream_nr); + + if (list_empty(&stream->subrequests)) + return; + + if (stream->source == NETFS_UPLOAD_TO_SERVER && + wreq->netfs_ops->retry_request) + wreq->netfs_ops->retry_request(wreq, stream); + + if (unlikely(stream->failed)) + return; + + /* If there's no renegotiation to do, just resend each failed subreq. */ + if (!stream->prepare_write) { + struct netfs_io_subrequest *subreq; + + list_for_each_entry(subreq, &stream->subrequests, rreq_link) { + if (test_bit(NETFS_SREQ_FAILED, &subreq->flags)) + break; + if (__test_and_clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) { + struct iov_iter source = subreq->io_iter; + + iov_iter_revert(&source, subreq->len - source.count); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); + netfs_reissue_write(stream, subreq, &source); + } + } + return; + } + + next = stream->subrequests.next; + + do { + struct netfs_io_subrequest *subreq = NULL, *from, *to, *tmp; + struct iov_iter source; + unsigned long long start, len; + size_t part; + bool boundary = false; + + /* Go through the stream and find the next span of contiguous + * data that we then rejig (cifs, for example, needs the wsize + * renegotiating) and reissue. + */ + from = list_entry(next, struct netfs_io_subrequest, rreq_link); + to = from; + start = from->start + from->transferred; + len = from->len - from->transferred; + + if (test_bit(NETFS_SREQ_FAILED, &from->flags) || + !test_bit(NETFS_SREQ_NEED_RETRY, &from->flags)) + return; + + list_for_each_continue(next, &stream->subrequests) { + subreq = list_entry(next, struct netfs_io_subrequest, rreq_link); + if (subreq->start + subreq->transferred != start + len || + test_bit(NETFS_SREQ_BOUNDARY, &subreq->flags) || + !test_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags)) + break; + to = subreq; + len += to->len; + } + + /* Determine the set of buffers we're going to use. Each + * subreq gets a subset of a single overall contiguous buffer. + */ + netfs_reset_iter(from); + source = from->io_iter; + source.count = len; + + /* Work through the sublist. */ + subreq = from; + list_for_each_entry_from(subreq, &stream->subrequests, rreq_link) { + if (!len) + break; + + subreq->start = start; + subreq->len = len; + __clear_bit(NETFS_SREQ_NEED_RETRY, &subreq->flags); + subreq->retry_count++; + trace_netfs_sreq(subreq, netfs_sreq_trace_retry); + + /* Renegotiate max_len (wsize) */ + stream->sreq_max_len = len; + stream->prepare_write(subreq); + + part = umin(len, stream->sreq_max_len); + if (unlikely(stream->sreq_max_segs)) + part = netfs_limit_iter(&source, 0, part, stream->sreq_max_segs); + subreq->len = part; + subreq->transferred = 0; + len -= part; + start += part; + if (len && subreq == to && + __test_and_clear_bit(NETFS_SREQ_BOUNDARY, &to->flags)) + boundary = true; + + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); + netfs_reissue_write(stream, subreq, &source); + if (subreq == to) + break; + } + + /* If we managed to use fewer subreqs, we can discard the + * excess; if we used the same number, then we're done. + */ + if (!len) { + if (subreq == to) + continue; + list_for_each_entry_safe_from(subreq, tmp, + &stream->subrequests, rreq_link) { + trace_netfs_sreq(subreq, netfs_sreq_trace_discard); + list_del(&subreq->rreq_link); + netfs_put_subrequest(subreq, false, netfs_sreq_trace_put_done); + if (subreq == to) + break; + } + continue; + } + + /* We ran out of subrequests, so we need to allocate some more + * and insert them after. + */ + do { + subreq = netfs_alloc_subrequest(wreq); + subreq->source = to->source; + subreq->start = start; + subreq->debug_index = atomic_inc_return(&wreq->subreq_counter); + subreq->stream_nr = to->stream_nr; + subreq->retry_count = 1; + + trace_netfs_sreq_ref(wreq->debug_id, subreq->debug_index, + refcount_read(&subreq->ref), + netfs_sreq_trace_new); + netfs_get_subrequest(subreq, netfs_sreq_trace_get_resubmit); + + list_add(&subreq->rreq_link, &to->rreq_link); + to = list_next_entry(to, rreq_link); + trace_netfs_sreq(subreq, netfs_sreq_trace_retry); + + stream->sreq_max_len = len; + stream->sreq_max_segs = INT_MAX; + switch (stream->source) { + case NETFS_UPLOAD_TO_SERVER: + netfs_stat(&netfs_n_wh_upload); + stream->sreq_max_len = umin(len, wreq->wsize); + break; + case NETFS_WRITE_TO_CACHE: + netfs_stat(&netfs_n_wh_write); + break; + default: + WARN_ON_ONCE(1); + } + + stream->prepare_write(subreq); + + part = umin(len, stream->sreq_max_len); + subreq->len = subreq->transferred + part; + len -= part; + start += part; + if (!len && boundary) { + __set_bit(NETFS_SREQ_BOUNDARY, &to->flags); + boundary = false; + } + + netfs_reissue_write(stream, subreq, &source); + if (!len) + break; + + } while (len); + + } while (!list_is_head(next, &stream->subrequests)); +} + +/* + * Perform retries on the streams that need it. If we're doing content + * encryption and the server copy changed due to a third-party write, we may + * need to do an RMW cycle and also rewrite the data to the cache. + */ +void netfs_retry_writes(struct netfs_io_request *wreq) +{ + struct netfs_io_subrequest *subreq; + struct netfs_io_stream *stream; + int s; + + netfs_stat(&netfs_n_wh_retry_write_req); + + /* Wait for all outstanding I/O to quiesce before performing retries as + * we may need to renegotiate the I/O sizes. + */ + for (s = 0; s < NR_IO_STREAMS; s++) { + stream = &wreq->io_streams[s]; + if (!stream->active) + continue; + + list_for_each_entry(subreq, &stream->subrequests, rreq_link) { + wait_on_bit(&subreq->flags, NETFS_SREQ_IN_PROGRESS, + TASK_UNINTERRUPTIBLE); + } + } + + // TODO: Enc: Fetch changed partial pages + // TODO: Enc: Reencrypt content if needed. + // TODO: Enc: Wind back transferred point. + // TODO: Enc: Mark cache pages for retry. + + for (s = 0; s < NR_IO_STREAMS; s++) { + stream = &wreq->io_streams[s]; + if (stream->need_retry) { + stream->need_retry = false; + netfs_retry_write_stream(wreq, stream); + } + } +} |