Take a reference on a page when PG_private_2 is set and drop it once the bit is unlocked[1]. Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> cc: linux-mm@xxxxxxxxx cc: linux-cachefs@xxxxxxxxxx cc: linux-afs@xxxxxxxxxxxxxxxxxxx cc: linux-nfs@xxxxxxxxxxxxxxx cc: linux-cifs@xxxxxxxxxxxxxxx cc: ceph-devel@xxxxxxxxxxxxxxx cc: v9fs-developer@xxxxxxxxxxxxxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/CAHk-=wh+2gbF7XEjYc=HV9w_2uVzVf7vs60BPz0gFA=+pUm3ww@xxxxxxxxxxxxxx/ [1] Link: https://lore.kernel.org/r/1331025.1612974993@xxxxxxxxxxxxxxxxxxxxxx/ Link: https://lore.kernel.org/r/161340400833.1303470.8070750156044982282.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v3 --- 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 0a7b76c11c98..ce11ca4c32e4 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> @@ -238,10 +239,13 @@ static void netfs_rreq_unmark_after_write(struct netfs_read_request *rreq, bool was_async) { 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) { @@ -255,6 +259,8 @@ 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; } } @@ -413,8 +419,10 @@ 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;
