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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/netfs/misc.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/netfs/misc.c')
-rw-r--r--fs/netfs/misc.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c
new file mode 100644
index 000000000..5d554512e
--- /dev/null
+++ b/fs/netfs/misc.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Miscellaneous routines.
+ *
+ * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/swap.h>
+#include "internal.h"
+
+/**
+ * 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.
+ */
+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 = *_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;
+ }
+
+ if (size - *_cur_size > PAGE_SIZE)
+ order = umin(ilog2(size - *_cur_size) - PAGE_SHIFT,
+ MAX_PAGECACHE_ORDER);
+
+ folio = folio_alloc(gfp, order);
+ if (!folio && order > 0)
+ folio = folio_alloc(gfp, 0);
+ if (!folio)
+ return -ENOMEM;
+
+ 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);
+
+ return 0;
+}
+EXPORT_SYMBOL(netfs_alloc_folioq_buffer);
+
+/**
+ * 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.
+ */
+void netfs_free_folioq_buffer(struct folio_queue *fq)
+{
+ struct folio_queue *next;
+ struct folio_batch fbatch;
+
+ folio_batch_init(&fbatch);
+
+ for (; fq; fq = next) {
+ for (int slot = 0; slot < folioq_count(fq); slot++) {
+ struct folio *folio = folioq_folio(fq, slot);
+
+ if (!folio ||
+ !folioq_is_marked(fq, slot))
+ continue;
+
+ trace_netfs_folio(folio, netfs_folio_trace_put);
+ if (folio_batch_add(&fbatch, folio))
+ folio_batch_release(&fbatch);
+ }
+
+ netfs_stat_d(&netfs_n_folioq);
+ 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
+ * 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.
+ * @folio: The folio being dirtied.
+ *
+ * Set the dirty flag on a folio and pin an in-use cache object in memory so
+ * that writeback can later write to it. This is intended to be called from
+ * the filesystem's ->dirty_folio() method.
+ *
+ * Return: true if the dirty flag was set on the folio, false otherwise.
+ */
+bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio)
+{
+ struct inode *inode = mapping->host;
+ struct netfs_inode *ictx = netfs_inode(inode);
+ struct fscache_cookie *cookie = netfs_i_cookie(ictx);
+ bool need_use = false;
+
+ _enter("");
+
+ if (!filemap_dirty_folio(mapping, folio))
+ return false;
+ if (!fscache_cookie_valid(cookie))
+ return true;
+
+ if (!(inode_state_read_once(inode) & I_PINNING_NETFS_WB)) {
+ spin_lock(&inode->i_lock);
+ if (!(inode_state_read(inode) & I_PINNING_NETFS_WB)) {
+ inode_state_set(inode, I_PINNING_NETFS_WB);
+ need_use = true;
+ }
+ spin_unlock(&inode->i_lock);
+
+ if (need_use)
+ fscache_use_cookie(cookie, true);
+ }
+ return true;
+}
+EXPORT_SYMBOL(netfs_dirty_folio);
+
+/**
+ * netfs_unpin_writeback - Unpin writeback resources
+ * @inode: The inode on which the cookie resides
+ * @wbc: The writeback control
+ *
+ * Unpin the writeback resources pinned by netfs_dirty_folio(). This is
+ * intended to be called as/by the netfs's ->write_inode() method.
+ */
+int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc)
+{
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
+
+ if (wbc->unpinned_netfs_wb)
+ fscache_unuse_cookie(cookie, NULL, NULL);
+ return 0;
+}
+EXPORT_SYMBOL(netfs_unpin_writeback);
+
+/**
+ * netfs_clear_inode_writeback - Clear writeback resources pinned by an inode
+ * @inode: The inode to clean up
+ * @aux: Auxiliary data to apply to the inode
+ *
+ * Clear any writeback resources held by an inode when the inode is evicted.
+ * This must be called before clear_inode() is called.
+ */
+void netfs_clear_inode_writeback(struct inode *inode, const void *aux)
+{
+ struct fscache_cookie *cookie = netfs_i_cookie(netfs_inode(inode));
+
+ if (inode_state_read_once(inode) & I_PINNING_NETFS_WB) {
+ loff_t i_size = i_size_read(inode);
+ fscache_unuse_cookie(cookie, aux, &i_size);
+ }
+}
+EXPORT_SYMBOL(netfs_clear_inode_writeback);
+
+/**
+ * netfs_invalidate_folio - Invalidate or partially invalidate a folio
+ * @folio: Folio proposed for release
+ * @offset: Offset of the invalidated region
+ * @length: Length of the invalidated region
+ *
+ * Invalidate part or all of a folio for a network filesystem. The folio will
+ * be removed afterwards if the invalidated region covers the entire folio.
+ */
+void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length)
+{
+ struct netfs_folio *finfo;
+ struct inode *inode = folio_inode(folio);
+ struct netfs_inode *ctx = netfs_inode(inode);
+ size_t flen = folio_size(folio);
+
+ _enter("{%lx},%zx,%zx", folio->index, offset, length);
+
+ if (offset == 0 && length == flen) {
+ unsigned long long i_size, remote_i_size, zero_point;
+ unsigned long long fpos = folio_pos(folio), end;
+
+ netfs_read_sizes(inode, &i_size, &remote_i_size, &zero_point);
+ end = umin(fpos + flen, i_size);
+ if (fpos < i_size && end > zero_point) {
+ spin_lock(&inode->i_lock);
+ end = umin(fpos + flen, inode->i_size);
+ if (fpos < i_size && end > ctx->_zero_point)
+ netfs_write_zero_point(inode, end);
+ spin_unlock(&inode->i_lock);
+ }
+ }
+
+ folio_wait_private_2(folio); /* [DEPRECATED] */
+
+ if (!folio_test_private(folio))
+ return;
+
+ finfo = netfs_folio_info(folio);
+
+ if (offset == 0 && length >= flen)
+ goto erase_completely;
+
+ if (finfo) {
+ /* We have a partially uptodate page from a streaming write. */
+ unsigned int fstart = finfo->dirty_offset;
+ unsigned int fend = fstart + finfo->dirty_len;
+ unsigned int iend = offset + length;
+
+ if (offset >= fend)
+ return;
+ if (iend <= fstart)
+ return;
+
+ /* The invalidation region overlaps the data. If the region
+ * covers the start of the data, we either move along the start
+ * or just erase the data entirely.
+ */
+ if (offset <= fstart) {
+ if (iend >= fend)
+ goto erase_completely;
+ /* Move the start of the data. */
+ finfo->dirty_len = fend - iend;
+ finfo->dirty_offset = iend;
+ trace_netfs_folio(folio, netfs_folio_trace_invalidate_front);
+ return;
+ }
+
+ /* Reduce the length of the data if the invalidation region
+ * covers the tail part.
+ */
+ if (iend >= fend) {
+ finfo->dirty_len = offset - fstart;
+ trace_netfs_folio(folio, netfs_folio_trace_invalidate_tail);
+ return;
+ }
+
+ /* A partial write was split. The caller has already zeroed
+ * it, so just absorb the hole.
+ */
+ trace_netfs_folio(folio, netfs_folio_trace_invalidate_middle);
+ }
+ return;
+
+erase_completely:
+ netfs_put_group(netfs_folio_group(folio));
+ folio_detach_private(folio);
+ folio_clear_uptodate(folio);
+ folio_cancel_dirty(folio);
+ kfree(finfo);
+ trace_netfs_folio(folio, netfs_folio_trace_invalidate_all);
+}
+EXPORT_SYMBOL(netfs_invalidate_folio);
+
+/**
+ * netfs_release_folio - Try to release a folio
+ * @folio: Folio proposed for release
+ * @gfp: Flags qualifying the release
+ *
+ * Request release of a folio and clean up its private state if it's not busy.
+ * Returns true if the folio can now be released, false if not
+ */
+bool netfs_release_folio(struct folio *folio, gfp_t gfp)
+{
+ struct inode *inode = folio_inode(folio);
+ struct netfs_inode *ctx = netfs_inode(inode);
+ unsigned long long i_size, remote_i_size, zero_point, end;
+
+ if (folio_test_dirty(folio))
+ return false;
+
+ netfs_read_sizes(inode, &i_size, &remote_i_size, &zero_point);
+ end = folio_next_pos(folio);
+ if (end > zero_point) {
+ spin_lock(&inode->i_lock);
+ end = umin(end, ctx->_remote_i_size);
+ if (end > ctx->_zero_point)
+ netfs_write_zero_point(inode, end);
+ spin_unlock(&inode->i_lock);
+ }
+
+ if (folio_test_private(folio))
+ return false;
+ if (unlikely(folio_test_private_2(folio))) { /* [DEPRECATED] */
+ if (current_is_kswapd() || !(gfp & __GFP_FS))
+ return false;
+ folio_wait_private_2(folio);
+ }
+ fscache_note_page_release(netfs_i_cookie(ctx));
+ return true;
+}
+EXPORT_SYMBOL(netfs_release_folio);
+
+/*
+ * Wake the collection work item.
+ */
+void netfs_wake_collector(struct netfs_io_request *rreq)
+{
+ if (test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags) &&
+ !test_bit(NETFS_RREQ_RETRYING, &rreq->flags)) {
+ queue_work(system_dfl_wq, &rreq->work);
+ } else {
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wake_queue);
+ wake_up(&rreq->waitq);
+ }
+}
+
+/*
+ * Mark a subrequest as no longer being in progress and, if need be, wake the
+ * collector.
+ */
+void netfs_subreq_clear_in_progress(struct netfs_io_subrequest *subreq)
+{
+ struct netfs_io_request *rreq = subreq->rreq;
+ struct netfs_io_stream *stream = &rreq->io_streams[subreq->stream_nr];
+
+ clear_bit_unlock(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
+ smp_mb__after_atomic(); /* Clear IN_PROGRESS before task state */
+
+ /* 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_collector(rreq);
+}
+
+/*
+ * Wait for all outstanding I/O in a stream to quiesce.
+ */
+void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
+ struct netfs_io_stream *stream)
+{
+ struct netfs_io_subrequest *subreq;
+ DEFINE_WAIT(myself);
+
+ list_for_each_entry(subreq, &stream->subrequests, rreq_link) {
+ smp_rmb(); /* Read ->next before IN_PROGRESS. */
+ if (!netfs_check_subreq_in_progress(subreq))
+ continue;
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wait_quiesce);
+ for (;;) {
+ prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
+
+ if (!netfs_check_subreq_in_progress(subreq))
+ break;
+
+ trace_netfs_sreq(subreq, netfs_sreq_trace_wait_for);
+ schedule();
+ }
+ }
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_waited_quiesce);
+ finish_wait(&rreq->waitq, &myself);
+}
+
+/*
+ * Perform collection in app thread if not offloaded to workqueue.
+ */
+static int netfs_collect_in_app(struct netfs_io_request *rreq,
+ bool (*collector)(struct netfs_io_request *rreq))
+{
+ bool need_collect = false, inactive = true, done = true;
+
+ if (!netfs_check_rreq_in_progress(rreq)) {
+ trace_netfs_rreq(rreq, netfs_rreq_trace_recollect);
+ return 1; /* Done */
+ }
+
+ for (int i = 0; i < NR_IO_STREAMS; i++) {
+ struct netfs_io_subrequest *subreq;
+ struct netfs_io_stream *stream = &rreq->io_streams[i];
+
+ if (!stream->active)
+ continue;
+ inactive = false;
+ trace_netfs_collect_stream(rreq, stream);
+ subreq = list_first_entry_or_null(&stream->subrequests,
+ struct netfs_io_subrequest,
+ rreq_link);
+ if (subreq &&
+ (!netfs_check_subreq_in_progress(subreq) ||
+ test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) {
+ need_collect = true;
+ break;
+ }
+ if (subreq || !test_bit(NETFS_RREQ_ALL_QUEUED, &rreq->flags))
+ done = false;
+ }
+
+ if (!need_collect && !inactive && !done)
+ return 0; /* Sleep */
+
+ __set_current_state(TASK_RUNNING);
+ if (collector(rreq)) {
+ /* Drop the ref from the NETFS_RREQ_IN_PROGRESS flag. */
+ netfs_put_request(rreq, netfs_rreq_trace_put_work_ip);
+ return 1; /* Done */
+ }
+
+ if (inactive) {
+ WARN(true, "Failed to collect inactive req R=%08x\n",
+ rreq->debug_id);
+ cond_resched();
+ }
+ return 2; /* Again */
+}
+
+/*
+ * Wait for a request to complete, successfully or otherwise.
+ */
+static ssize_t netfs_wait_for_in_progress(struct netfs_io_request *rreq,
+ bool (*collector)(struct netfs_io_request *rreq))
+{
+ DEFINE_WAIT(myself);
+ ssize_t ret;
+
+ for (;;) {
+ prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
+
+ if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) {
+ switch (netfs_collect_in_app(rreq, collector)) {
+ case 0:
+ break;
+ case 1:
+ goto all_collected;
+ case 2:
+ if (!netfs_check_rreq_in_progress(rreq))
+ break;
+ cond_resched();
+ continue;
+ }
+ }
+
+ if (!netfs_check_rreq_in_progress(rreq))
+ break;
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wait_ip);
+ schedule();
+ }
+
+all_collected:
+ trace_netfs_rreq(rreq, netfs_rreq_trace_waited_ip);
+ finish_wait(&rreq->waitq, &myself);
+
+ ret = rreq->error;
+ if (ret == 0) {
+ ret = rreq->transferred;
+ switch (rreq->origin) {
+ case NETFS_DIO_READ:
+ case NETFS_DIO_WRITE:
+ case NETFS_READ_SINGLE:
+ case NETFS_UNBUFFERED_READ:
+ case NETFS_UNBUFFERED_WRITE:
+ break;
+ default:
+ if (rreq->submitted < rreq->len) {
+ trace_netfs_failure(rreq, NULL, ret, netfs_fail_short_read);
+ ret = -EIO;
+ }
+ break;
+ }
+ }
+
+ return ret;
+}
+
+ssize_t netfs_wait_for_read(struct netfs_io_request *rreq)
+{
+ return netfs_wait_for_in_progress(rreq, netfs_read_collection);
+}
+
+ssize_t netfs_wait_for_write(struct netfs_io_request *rreq)
+{
+ return netfs_wait_for_in_progress(rreq, netfs_write_collection);
+}
+
+/*
+ * Wait for a paused operation to unpause or complete in some manner.
+ */
+static void netfs_wait_for_pause(struct netfs_io_request *rreq,
+ bool (*collector)(struct netfs_io_request *rreq))
+{
+ DEFINE_WAIT(myself);
+
+ for (;;) {
+ trace_netfs_rreq(rreq, netfs_rreq_trace_wait_pause);
+ prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
+
+ if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) {
+ switch (netfs_collect_in_app(rreq, collector)) {
+ case 0:
+ break;
+ case 1:
+ goto all_collected;
+ case 2:
+ if (!netfs_check_rreq_in_progress(rreq) ||
+ !test_bit(NETFS_RREQ_PAUSE, &rreq->flags))
+ break;
+ cond_resched();
+ continue;
+ }
+ }
+
+ if (!netfs_check_rreq_in_progress(rreq) ||
+ !test_bit(NETFS_RREQ_PAUSE, &rreq->flags))
+ break;
+
+ schedule();
+ }
+
+all_collected:
+ trace_netfs_rreq(rreq, netfs_rreq_trace_waited_pause);
+ finish_wait(&rreq->waitq, &myself);
+}
+
+void netfs_wait_for_paused_read(struct netfs_io_request *rreq)
+{
+ return netfs_wait_for_pause(rreq, netfs_read_collection);
+}
+
+void netfs_wait_for_paused_write(struct netfs_io_request *rreq)
+{
+ return netfs_wait_for_pause(rreq, netfs_write_collection);
+}