diff options
| -rw-r--r-- | fs/fuse/virtio_fs.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c index 5200ad50ed10..f9c1aa1d289c 100644 --- a/fs/fuse/virtio_fs.c +++ b/fs/fuse/virtio_fs.c @@ -1018,18 +1018,37 @@ __releases(fiq->lock) spin_unlock(&fiq->lock); } +/* Count number of scatter-gather elements required */ +static unsigned int sg_count_fuse_pages(struct fuse_page_desc *page_descs, + unsigned int num_pages, + unsigned int total_len) +{ + unsigned int i; + unsigned int this_len; + + for (i = 0; i < num_pages && total_len; i++) { + this_len = min(page_descs[i].length, total_len); + total_len -= this_len; + } + + return i; +} + /* Return the number of scatter-gather list elements required */ static unsigned int sg_count_fuse_req(struct fuse_req *req) { struct fuse_args *args = req->args; struct fuse_args_pages *ap = container_of(args, typeof(*ap), args); - unsigned int total_sgs = 1 /* fuse_in_header */; + unsigned int size, total_sgs = 1 /* fuse_in_header */; if (args->in_numargs - args->in_pages) total_sgs += 1; - if (args->in_pages) - total_sgs += ap->num_pages; + if (args->in_pages) { + size = args->in_args[args->in_numargs - 1].size; + total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages, + size); + } if (!test_bit(FR_ISREPLY, &req->flags)) return total_sgs; @@ -1039,8 +1058,11 @@ static unsigned int sg_count_fuse_req(struct fuse_req *req) if (args->out_numargs - args->out_pages) total_sgs += 1; - if (args->out_pages) - total_sgs += ap->num_pages; + if (args->out_pages) { + size = args->out_args[args->out_numargs - 1].size; + total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages, + size); + } return total_sgs; } |