From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Some filesystem writeback routines can end up taking up a lot of stack space (particularly xfs). Instead of risking running over due to the extra overhead from the NFS stack, we should just call these routines from a workqueue job. Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- fs/nfs/localio.c | 51 ++++++++++++++++++++++++++++++++++++------------ 1 file changed, 38 insertions(+), 13 deletions(-) diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c index 5939ca2216be..2c6811b20dcf 100644 --- a/fs/nfs/localio.c +++ b/fs/nfs/localio.c @@ -63,6 +63,12 @@ struct nfs_local_fsync_ctx { }; static void nfs_local_fsync_work(struct work_struct *work); +struct nfs_local_io_args { + struct nfs_local_kiocb *iocb; + struct work_struct work; + struct completion *done; +}; + /* * We need to translate between nfs status return values and * the local errno values which may not be the same. @@ -597,14 +603,35 @@ nfs_local_write_aio_complete(struct kiocb *kiocb, long ret) nfs_local_pgio_complete(iocb); } -static int -nfs_do_local_write(struct nfs_pgio_header *hdr, struct file *filp, - const struct rpc_call_ops *call_ops) +static void nfs_local_call_write(struct work_struct *work) { - struct nfs_local_kiocb *iocb; + struct nfs_local_io_args *args = + container_of(work, struct nfs_local_io_args, work); + struct nfs_local_kiocb *iocb = args->iocb; + struct file *filp = iocb->kiocb.ki_filp; struct iov_iter iter; ssize_t status; + nfs_local_iter_init(&iter, iocb, WRITE); + + file_start_write(filp); + status = filp->f_op->write_iter(&iocb->kiocb, &iter); + file_end_write(filp); + if (status != -EIOCBQUEUED) { + nfs_local_write_done(iocb, status); + nfs_get_vfs_attr(filp, iocb->hdr->res.fattr); + nfs_local_pgio_release(iocb); + } + complete(args->done); +} + +static int nfs_do_local_write(struct nfs_pgio_header *hdr, struct file *filp, + const struct rpc_call_ops *call_ops) +{ + struct nfs_local_io_args args; + DECLARE_COMPLETION_ONSTACK(done); + struct nfs_local_kiocb *iocb; + dprintk("%s: vfs_write count=%u pos=%llu %s\n", __func__, hdr->args.count, hdr->args.offset, (hdr->args.stable == NFS_UNSTABLE) ? "unstable" : "stable"); @@ -612,7 +639,6 @@ nfs_do_local_write(struct nfs_pgio_header *hdr, struct file *filp, iocb = nfs_local_iocb_alloc(hdr, filp, GFP_NOIO); if (iocb == NULL) return -ENOMEM; - nfs_local_iter_init(&iter, iocb, WRITE); switch (hdr->args.stable) { default: @@ -632,14 +658,13 @@ nfs_do_local_write(struct nfs_pgio_header *hdr, struct file *filp, nfs_set_local_verifier(hdr->inode, hdr->res.verf, hdr->args.stable); - file_start_write(filp); - status = filp->f_op->write_iter(&iocb->kiocb, &iter); - file_end_write(filp); - if (status != -EIOCBQUEUED) { - nfs_local_write_done(iocb, status); - nfs_get_vfs_attr(filp, hdr->res.fattr); - nfs_local_pgio_release(iocb); - } + args.iocb = iocb; + args.done = &done; + INIT_WORK_ONSTACK(&args.work, nfs_local_call_write); + + queue_work(nfsiod_workqueue, &args.work); + wait_for_completion(&done); + destroy_work_on_stack(&args.work); return 0; } -- 2.44.0