[PATCH 13/33] netfs: Hold a ref on a page when PG_private_2 is set
From: David Howells <dhowells@redhat.com>
Date: 2021-02-15 15:59:39
Also in:
ceph-devel, linux-fsdevel, linux-mm, linux-nfs, lkml
Subsystem:
filesystems (vfs and infrastructure), filesystems [netfs library], the rest · Maintainers:
Alexander Viro, Christian Brauner, David Howells, Paulo Alcantara, Linus Torvalds
Take a reference on a page when PG_private_2 is set and drop it once the bit is unlocked. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Howells <dhowells@redhat.com> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: linux-mm@kvack.org cc: linux-cachefs@redhat.com cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/linux-fsdevel/1331025.1612974993@warthog.procyon.org.uk/ (local) --- fs/netfs/read_helper.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/fs/netfs/read_helper.c b/fs/netfs/read_helper.c
index 156941e0de61..9191a3617d91 100644
--- a/fs/netfs/read_helper.c
+++ b/fs/netfs/read_helper.c@@ -10,6 +10,7 @@ #include <linux/fs.h> #include <linux/mm.h> #include <linux/pagemap.h> +#include <linux/pagevec.h> #include <linux/slab.h> #include <linux/uio.h> #include <linux/sched/mm.h>
@@ -230,10 +231,13 @@ static void netfs_rreq_completed(struct netfs_read_request *rreq) static void netfs_rreq_unmark_after_write(struct netfs_read_request *rreq) { struct netfs_read_subrequest *subreq; + struct pagevec pvec; struct page *page; pgoff_t unlocked = 0; bool have_unlocked = false; + pagevec_init(&pvec); + rcu_read_lock(); list_for_each_entry(subreq, &rreq->subrequests, rreq_link) {
@@ -247,6 +251,8 @@ static void netfs_rreq_unmark_after_write(struct netfs_read_request *rreq) continue; unlocked = page->index; unlock_page_fscache(page); + if (pagevec_add(&pvec, page) == 0) + pagevec_release(&pvec); have_unlocked = true; } }
@@ -403,8 +409,10 @@ static void netfs_rreq_unlock(struct netfs_read_request *rreq) pg_failed = true; break; } - if (test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags)) + if (test_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags)) { + get_page(page); SetPageFsCache(page); + } pg_failed |= subreq_failed; if (pgend < iopos + subreq->len) break;