[PATCH 06/26] netfs: Remove deprecated use of PG_private_2 as a second writeback flag

From: David Howells
Date: Thu Mar 28 2024 - 12:38:13 EST


Remove the deprecated use of PG_private_2 in netfslib.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Jeff Layton <jlayton@xxxxxxxxxx>
cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
cc: linux-cachefs@xxxxxxxxxx
cc: linux-fsdevel@xxxxxxxxxxxxxxx
cc: linux-mm@xxxxxxxxx
---
fs/ceph/addr.c | 19 +-----
fs/netfs/buffered_read.c | 8 +--
fs/netfs/io.c | 144 ---------------------------------------
3 files changed, 2 insertions(+), 169 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 75690f969ebc..2d0f13537c85 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -498,11 +498,6 @@ 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;
@@ -520,10 +515,6 @@ 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)
{
}
@@ -715,8 +706,6 @@ 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)) {
@@ -798,8 +787,6 @@ static int ceph_writepage(struct page *page, struct writeback_control *wbc)
ceph_inode_to_fs_client(inode)->write_congested)
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
@@ -1073,8 +1060,7 @@ static int ceph_writepages_start(struct address_space *mapping,
unlock_page(page);
break;
}
- if (PageWriteback(page) ||
- PagePrivate2(page) /* [DEPRECATED] */) {
+ if (PageWriteback(page)) {
if (wbc->sync_mode == WB_SYNC_NONE) {
doutc(cl, "%p under writeback\n", page);
unlock_page(page);
@@ -1082,7 +1068,6 @@ 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)) {
@@ -1267,8 +1252,6 @@ 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 b3fd6e1fa322..1622cce535a3 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -464,7 +464,7 @@ 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_no_wait;
+ goto have_folio;
}

rreq = netfs_alloc_request(mapping, file,
@@ -505,12 +505,6 @@ 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 60a19f96e0ce..2641238aae82 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -98,146 +98,6 @@ 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.
*/
@@ -410,10 +270,6 @@ 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);
}