From cd0277ed0c188dd40e7744e89299af7b78831ca4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 29 May 2024 21:47:07 +0100 Subject: netfs: Use new folio_queue data type and iterator instead of xarray iter Make the netfs write-side routines use the new folio_queue struct to hold a rolling buffer of folios, with the issuer adding folios at the tail and the collector removing them from the head as they're processed instead of using an xarray. This will allow a subsequent patch to simplify the write collector. The primary mark (as tested by folioq_is_marked()) is used to note if the corresponding folio needs putting. Signed-off-by: David Howells cc: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20240814203850.2240469-16-dhowells@redhat.com/ # v2 Signed-off-by: Christian Brauner --- fs/netfs/misc.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) (limited to 'fs/netfs/misc.c') diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index c1f321cf5999..4cd2f84415c1 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -8,6 +8,82 @@ #include #include "internal.h" +/* + * 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 = rreq->buffer_tail; + unsigned int slot, order = folio_order(folio); + + if (WARN_ON_ONCE(!rreq->buffer && tail) || + WARN_ON_ONCE(rreq->buffer && !tail)) + return -EIO; + + if (!tail || folioq_full(tail)) { + tail = kmalloc(sizeof(*tail), GFP_NOFS); + if (!tail) + return -ENOMEM; + netfs_stat(&netfs_n_folioq); + folioq_init(tail); + tail->prev = rreq->buffer_tail; + if (tail->prev) + tail->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); + } + rreq->buffer_tail_slot = 0; + } + + rreq->io_iter.count += PAGE_SIZE << order; + + slot = folioq_append(tail, folio); + /* Store the counter after setting the slot. */ + smp_store_release(&rreq->buffer_tail_slot, slot); + return 0; +} + +/* + * Delete the head of a rolling queue. + */ +struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq) +{ + 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; +} + +/* + * Clear out a rolling queue. + */ +void netfs_clear_buffer(struct netfs_io_request *rreq) +{ + struct folio_queue *p; + + while ((p = rreq->buffer)) { + rreq->buffer = p->next; + for (int slot = 0; slot < folioq_nr_slots(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); + folio_put(folio); + } + } + netfs_stat_d(&netfs_n_folioq); + kfree(p); + } +} + /** * netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback * @mapping: The mapping the folio belongs to. -- cgit From bfaa33b8ba196f9506a45e5a36e968f087c8cd16 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 8 Jul 2024 14:49:45 +0100 Subject: netfs: Provide an iterator-reset function Provide a function to reset the iterator on a subrequest. Signed-off-by: David Howells cc: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20240814203850.2240469-17-dhowells@redhat.com/ # v2 Signed-off-by: Christian Brauner --- fs/netfs/misc.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'fs/netfs/misc.c') diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index 4cd2f84415c1..0ad0982ce0e2 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -84,6 +84,24 @@ void netfs_clear_buffer(struct netfs_io_request *rreq) } } +/* + * Reset the subrequest iterator to refer just to the region remaining to be + * read. The iterator may or may not have been advanced by socket ops or + * extraction ops to an extent that may or may not match the amount actually + * read. + */ +void netfs_reset_iter(struct netfs_io_subrequest *subreq) +{ + struct iov_iter *io_iter = &subreq->io_iter; + size_t remain = subreq->len - subreq->transferred; + + if (io_iter->count > remain) + iov_iter_advance(io_iter, io_iter->count - remain); + else if (io_iter->count < remain) + iov_iter_revert(io_iter, remain - io_iter->count); + iov_iter_truncate(&subreq->io_iter, remain); +} + /** * netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback * @mapping: The mapping the folio belongs to. -- cgit