Hi Max,
Can you try this patch instead of either of yours?
David
---
This reverts commit ae678317b95e760607c7b20b97c9cd4ca9ed6e1a.
Revert the patch that removes the deprecated use of PG_private_2 in
netfslib for the moment as Ceph is actually still using this to track
data copied to the cache.
Fixes: ae678317b95e ("netfs: Remove deprecated use of PG_private_2 as a second writeback flag")
Reported-by: Max Kellermann <max.kellermann@xxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Ilya Dryomov <idryomov@xxxxxxxxx>
cc: Xiubo Li <xiubli@xxxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: ceph-devel@xxxxxxxxxxxxxxx
cc: netfs@xxxxxxxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
cc: linux-mm@xxxxxxxxx
---
fs/ceph/addr.c | 19 +++++
fs/netfs/buffered_read.c | 8 ++
fs/netfs/io.c | 144 +++++++++++++++++++++++++++++++++++++++++++
include/trace/events/netfs.h | 1
4 files changed, 170 insertions(+), 2 deletions(-)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 8c16bc5250ef..73b5a07bf94d 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -498,6 +498,11 @@ const struct netfs_request_ops ceph_netfs_ops = {
};
#ifdef CONFIG_CEPH_FSCACHE
+static void ceph_set_page_fscache(struct page *page)
+{
+ folio_start_private_2(page_folio(page)); /* [DEPRECATED] */
+}
+
static void ceph_fscache_write_terminated(void *priv, ssize_t error, bool was_async)
{
struct inode *inode = priv;
@@ -515,6 +520,10 @@ static void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, b
ceph_fscache_write_terminated, inode, true, caching);
}
#else
+static inline void ceph_set_page_fscache(struct page *page)
+{
+}
+
static inline void ceph_fscache_write_to_cache(struct inode *inode, u64 off, u64 len, bool caching)
{
}
@@ -706,6 +715,8 @@ static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
len = wlen;
set_page_writeback(page);
+ if (caching)
+ ceph_set_page_fscache(page);
ceph_fscache_write_to_cache(inode, page_off, len, caching);
if (IS_ENCRYPTED(inode)) {
@@ -789,6 +800,8 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
return AOP_WRITEPAGE_ACTIVATE;
}
+ folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
+
err = writepage_nounlock(page, wbc);
if (err == -ERESTARTSYS) {
/* direct memory reclaimer was killed by SIGKILL. return 0
@@ -1062,7 +1075,8 @@ static int ceph_writepages_start(struct address_space *mapping,
unlock_page(page);
break;
}
- if (PageWriteback(page)) {
+ if (PageWriteback(page) ||
+ PagePrivate2(page) /* [DEPRECATED] */) {
if (wbc->sync_mode == WB_SYNC_NONE) {
doutc(cl, "%p under writeback\n", page);
unlock_page(page);
@@ -1070,6 +1084,7 @@ static int ceph_writepages_start(struct address_space *mapping,
}
doutc(cl, "waiting on writeback %p\n", page);
wait_on_page_writeback(page);
+ folio_wait_private_2(page_folio(page)); /* [DEPRECATED] */
}
if (!clear_page_dirty_for_io(page)) {
@@ -1254,6 +1269,8 @@ static int ceph_writepages_start(struct address_space *mapping,
}
set_page_writeback(page);
+ if (caching)
+ ceph_set_page_fscache(page);
len += thp_size(page);
}
ceph_fscache_write_to_cache(inode, offset, len, caching);
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index a688d4c75d99..424048f9ed1f 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -466,7 +466,7 @@ int netfs_write_begin(struct netfs_inode *ctx,
if (!netfs_is_cache_enabled(ctx) &&
netfs_skip_folio_read(folio, pos, len, false)) {
netfs_stat(&netfs_n_rh_write_zskip);
- goto have_folio;
+ goto have_folio_no_wait;
}
rreq = netfs_alloc_request(mapping, file,
@@ -507,6 +507,12 @@ int netfs_write_begin(struct netfs_inode *ctx,
netfs_put_request(rreq, false, netfs_rreq_trace_put_return);
have_folio:
+ if (test_bit(NETFS_ICTX_USE_PGPRIV2, &ctx->flags)) {
+ ret = folio_wait_private_2_killable(folio);
+ if (ret < 0)
+ goto error;
+ }
+have_folio_no_wait:
*_folio = folio;
_leave(" = 0");
return 0;
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index c93851b98368..c179a1c73fa7 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -98,6 +98,146 @@ static void netfs_rreq_completed(struct netfs_io_request *rreq, bool was_async)
netfs_put_request(rreq, was_async, netfs_rreq_trace_put_complete);
}
+/*
+ * [DEPRECATED] Deal with the completion of writing the data to the cache. We
+ * have to clear the PG_fscache bits on the folios involved and release the
+ * caller's ref.
+ *
+ * May be called in softirq mode and we inherit a ref from the caller.
+ */
+static void netfs_rreq_unmark_after_write(struct netfs_io_request *rreq,
+ bool was_async)
+{
+ struct netfs_io_subrequest *subreq;
+ struct folio *folio;
+ pgoff_t unlocked = 0;
+ bool have_unlocked = false;
+
+ rcu_read_lock();
+
+ list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+ XA_STATE(xas, &rreq->mapping->i_pages, subreq->start / PAGE_SIZE);
+
+ xas_for_each(&xas, folio, (subreq->start + subreq->len - 1) / PAGE_SIZE) {
+ if (xas_retry(&xas, folio))
+ continue;
+
+ /* We might have multiple writes from the same huge
+ * folio, but we mustn't unlock a folio more than once.
+ */
+ if (have_unlocked && folio->index <= unlocked)
+ continue;
+ unlocked = folio_next_index(folio) - 1;
+ trace_netfs_folio(folio, netfs_folio_trace_end_copy);
+ folio_end_private_2(folio);
+ have_unlocked = true;
+ }
+ }
+
+ rcu_read_unlock();
+ netfs_rreq_completed(rreq, was_async);
+}
+
+static void netfs_rreq_copy_terminated(void *priv, ssize_t transferred_or_error,
+ bool was_async) /* [DEPRECATED] */
+{
+ struct netfs_io_subrequest *subreq = priv;
+ struct netfs_io_request *rreq = subreq->rreq;
+
+ if (IS_ERR_VALUE(transferred_or_error)) {
+ netfs_stat(&netfs_n_rh_write_failed);
+ trace_netfs_failure(rreq, subreq, transferred_or_error,
+ netfs_fail_copy_to_cache);
+ } else {
+ netfs_stat(&netfs_n_rh_write_done);
+ }
+
+ trace_netfs_sreq(subreq, netfs_sreq_trace_write_term);
+
+ /* If we decrement nr_copy_ops to 0, the ref belongs to us. */
+ if (atomic_dec_and_test(&rreq->nr_copy_ops))
+ netfs_rreq_unmark_after_write(rreq, was_async);
+
+ netfs_put_subrequest(subreq, was_async, netfs_sreq_trace_put_terminated);
+}
+
+/*
+ * [DEPRECATED] Perform any outstanding writes to the cache. We inherit a ref
+ * from the caller.
+ */
+static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq)
+{
+ struct netfs_cache_resources *cres = &rreq->cache_resources;
+ struct netfs_io_subrequest *subreq, *next, *p;
+ struct iov_iter iter;
+ int ret;
+
+ trace_netfs_rreq(rreq, netfs_rreq_trace_copy);
+
+ /* We don't want terminating writes trying to wake us up whilst we're
+ * still going through the list.
+ */
+ atomic_inc(&rreq->nr_copy_ops);
+
+ list_for_each_entry_safe(subreq, p, &rreq->subrequests, rreq_link) {
+ if (!test_bit(NETFS_SREQ_COPY_TO_CACHE, &subreq->flags)) {
+ list_del_init(&subreq->rreq_link);
+ netfs_put_subrequest(subreq, false,
+ netfs_sreq_trace_put_no_copy);
+ }
+ }
+
+ list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
+ /* Amalgamate adjacent writes */
+ while (!list_is_last(&subreq->rreq_link, &rreq->subrequests)) {
+ next = list_next_entry(subreq, rreq_link);
+ if (next->start != subreq->start + subreq->len)
+ break;
+ subreq->len += next->len;
+ list_del_init(&next->rreq_link);
+ netfs_put_subrequest(next, false,
+ netfs_sreq_trace_put_merged);
+ }
+
+ ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len,
+ subreq->len, rreq->i_size, true);
+ if (ret < 0) {
+ trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write);
+ trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip);
+ continue;
+ }
+
+ iov_iter_xarray(&iter, ITER_SOURCE, &rreq->mapping->i_pages,
+ subreq->start, subreq->len);
+
+ atomic_inc(&rreq->nr_copy_ops);
+ netfs_stat(&netfs_n_rh_write);
+ netfs_get_subrequest(subreq, netfs_sreq_trace_get_copy_to_cache);
+ trace_netfs_sreq(subreq, netfs_sreq_trace_write);
+ cres->ops->write(cres, subreq->start, &iter,
+ netfs_rreq_copy_terminated, subreq);
+ }
+
+ /* If we decrement nr_copy_ops to 0, the usage ref belongs to us. */
+ if (atomic_dec_and_test(&rreq->nr_copy_ops))
+ netfs_rreq_unmark_after_write(rreq, false);
+}
+
+static void netfs_rreq_write_to_cache_work(struct work_struct *work) /* [DEPRECATED] */
+{
+ struct netfs_io_request *rreq =
+ container_of(work, struct netfs_io_request, work);
+
+ netfs_rreq_do_write_to_cache(rreq);
+}
+
+static void netfs_rreq_write_to_cache(struct netfs_io_request *rreq) /* [DEPRECATED] */
+{
+ rreq->work.func = netfs_rreq_write_to_cache_work;
+ if (!queue_work(system_unbound_wq, &rreq->work))
+ BUG();
+}
+
/*
* Handle a short read.
*/
@@ -275,6 +415,10 @@ static void netfs_rreq_assess(struct netfs_io_request *rreq, bool was_async)
clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
wake_up_bit(&rreq->flags, NETFS_RREQ_IN_PROGRESS);
+ if (test_bit(NETFS_RREQ_COPY_TO_CACHE, &rreq->flags) &&
+ test_bit(NETFS_RREQ_USE_PGPRIV2, &rreq->flags))
+ return netfs_rreq_write_to_cache(rreq);
+
netfs_rreq_completed(rreq, was_async);
}
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index da23484268df..24ec3434d32e 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -145,6 +145,7 @@
EM(netfs_folio_trace_clear_g, "clear-g") \
EM(netfs_folio_trace_clear_s, "clear-s") \
EM(netfs_folio_trace_copy_to_cache, "mark-copy") \
+ EM(netfs_folio_trace_end_copy, "end-copy") \
EM(netfs_folio_trace_filled_gaps, "filled-gaps") \
EM(netfs_folio_trace_kill, "kill") \
EM(netfs_folio_trace_kill_cc, "kill-cc") \
