Add a bvec array pointer and an iterator to netfs_io_request for either holding a copy of a DIO iterator or a list of all the bits of buffer pointed to by a DIO iterator. There are two problems: Firstly, if an iovec-class iov_iter is passed to ->read_iter() or ->write_iter(), this cannot be passed directly to kernel_sendmsg() or kernel_recvmsg() as that may cause locking recursion if a fault is generated, so we need to keep track of the pages involved separately. Secondly, if the I/O is asynchronous, we must copy the iov_iter describing the buffer before returning to the caller as it may be immediately deallocated. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Jeff Layton <jlayton@xxxxxxxxxx> cc: linux-cachefs@xxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx cc: linux-mm@xxxxxxxxx --- fs/netfs/objects.c | 10 ++++++++++ include/linux/netfs.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 8e92b8401aaa..4396318081bf 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -78,6 +78,7 @@ static void netfs_free_request(struct work_struct *work) { struct netfs_io_request *rreq = container_of(work, struct netfs_io_request, work); + unsigned int i; trace_netfs_rreq(rreq, netfs_rreq_trace_free); netfs_proc_del_rreq(rreq); @@ -86,6 +87,15 @@ static void netfs_free_request(struct work_struct *work) rreq->netfs_ops->free_request(rreq); if (rreq->cache_resources.ops) rreq->cache_resources.ops->end_operation(&rreq->cache_resources); + if (rreq->direct_bv) { + for (i = 0; i < rreq->direct_bv_count; i++) { + if (rreq->direct_bv[i].bv_page) { + if (rreq->direct_bv_unpin) + unpin_user_page(rreq->direct_bv[i].bv_page); + } + } + kvfree(rreq->direct_bv); + } kfree_rcu(rreq, rcu); netfs_stat_d(&netfs_n_rh_rreq); } diff --git a/include/linux/netfs.h b/include/linux/netfs.h index bd0437088f0e..66479a61ad00 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -191,7 +191,9 @@ struct netfs_io_request { struct list_head subrequests; /* Contributory I/O operations */ struct iov_iter iter; /* Unencrypted-side iterator */ struct iov_iter io_iter; /* I/O (Encrypted-side) iterator */ + struct bio_vec *direct_bv; /* DIO buffer list (when handling iovec-iter) */ void *netfs_priv; /* Private data for the netfs */ + unsigned int direct_bv_count; /* Number of elements in bv[] */ unsigned int debug_id; unsigned int rsize; /* Maximum read size (0 for none) */ atomic_t nr_outstanding; /* Number of ops in progress */ @@ -200,6 +202,7 @@ struct netfs_io_request { size_t len; /* Length of the request */ short error; /* 0 or error that occurred */ enum netfs_io_origin origin; /* Origin of the request */ + bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */ loff_t i_size; /* Size of the file */ loff_t start; /* Start position */ pgoff_t no_unlock_folio; /* Don't unlock this folio after read */ -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/linux-cachefs