NFSv4.1 test the mdsthreshold hint parameters (d23d61c8) · Commits · EulixOS / Software / Kernel

fs/nfs/pnfs.c

+79 −0

Original line number	Diff line number	Diff line
		@@ -935,6 +935,81 @@ pnfs_find_lseg(struct pnfs_layout_hdr *lo,
		return ret;
		}

		/*
		* Use mdsthreshold hints set at each OPEN to determine if I/O should go
		* to the MDS or over pNFS
		*
		* The nfs_inode read_io and write_io fields are cumulative counters reset
		* when there are no layout segments. Note that in pnfs_update_layout iomode
		* is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
		* WRITE request.
		*
		* A return of true means use MDS I/O.
		*
		* From rfc 5661:
		* If a file's size is smaller than the file size threshold, data accesses
		* SHOULD be sent to the metadata server. If an I/O request has a length that
		* is below the I/O size threshold, the I/O SHOULD be sent to the metadata
		* server. If both file size and I/O size are provided, the client SHOULD
		* reach or exceed both thresholds before sending its read or write
		* requests to the data server.
		*/
		static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
		struct inode *ino, int iomode)
		{
		struct nfs4_threshold *t = ctx->mdsthreshold;
		struct nfs_inode *nfsi = NFS_I(ino);
		loff_t fsize = i_size_read(ino);
		bool size = false, size_set = false, io = false, io_set = false, ret = false;

		if (t == NULL)
		return ret;

		dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);

		switch (iomode) {
		case IOMODE_READ:
		if (t->bm & THRESHOLD_RD) {
		dprintk("%s fsize %llu\n", __func__, fsize);
		size_set = true;
		if (fsize < t->rd_sz)
		size = true;
		}
		if (t->bm & THRESHOLD_RD_IO) {
		dprintk("%s nfsi->read_io %llu\n", __func__,
		nfsi->read_io);
		io_set = true;
		if (nfsi->read_io < t->rd_io_sz)
		io = true;
		}
		break;
		case IOMODE_RW:
		if (t->bm & THRESHOLD_WR) {
		dprintk("%s fsize %llu\n", __func__, fsize);
		size_set = true;
		if (fsize < t->wr_sz)
		size = true;
		}
		if (t->bm & THRESHOLD_WR_IO) {
		dprintk("%s nfsi->write_io %llu\n", __func__,
		nfsi->write_io);
		io_set = true;
		if (nfsi->write_io < t->wr_io_sz)
		io = true;
		}
		break;
		}
		if (size_set && io_set) {
		if (size && io)
		ret = true;
		} else if (size \|\| io)
		ret = true;

		dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
		return ret;
		}

		/*
		* Layout segment is retreived from the server if not cached.
		* The appropriate layout segment is referenced and returned to the caller.
		@@ -962,6 +1037,10 @@ pnfs_update_layout(struct inode *ino,

		if (!pnfs_enabled_sb(NFS_SERVER(ino)))
		return NULL;

		if (pnfs_within_mdsthreshold(ctx, ino, iomode))
		return NULL;

		spin_lock(&ino->i_lock);
		lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
		if (lo == NULL) {