/* *  linux/fs/nfs/blocklayout/blocklayoutdev.c * *  Device operations for the pnfs nfs4 file layout driver. * *  Copyright (c) 2006 The Regents of the University of Michigan. *  All rights reserved. * *  Andy Adamson <andros@citi.umich.edu> *  Fred Isaman <iisaman@umich.edu> * * permission is granted to use, copy, create derivative works and * redistribute this software and such derivative works for any purpose, * so long as the name of the university of michigan is not used in * any advertising or publicity pertaining to the use or distribution * of this software without specific, written prior authorization.  if * the above copyright notice or any other identification of the * university of michigan is included in any copy of any portion of * this software, then the disclaimer below must also be included. * * this software is provided as is, without representation from the * university of michigan as to its fitness for any purpose, and without * warranty by the university of michigan of any kind, either express * or implied, including without limitation the implied warranties of * merchantability and fitness for a particular purpose.  the regents * of the university of michigan shall not be liable for any damages, * including special, indirect, incidental, or consequential damages, * with respect to any claim arising out or in connection with the use * of the software, even if it has been or is hereafter advised of the * possibility of such damages. */#include <linux/module.h>#include <linux/buffer_head.h> /* __bread */ #include <linux/genhd.h>#include <linux/blkdev.h>#include <linux/hash.h> #include "blocklayout.h" #define NFSDBG_FACILITY         NFSDBG_PNFS_LD static int decode_sector_number(__be32 **rp, sector_t *sp){	uint64_t s; 	*rp = xdr_decode_hyper(*rp, &s);	if (s & 0x1ff) {		printk(KERN_WARNING "NFS: %s: sector not aligned\n", __func__);		return -1;	}	*sp = s >> SECTOR_SHIFT;	return 0;} /* * Release the block device */void nfs4_blkdev_put(struct block_device *bdev){	dprintk("%s for device %d:%d\n", __func__, MAJOR(bdev->bd_dev),			MINOR(bdev->bd_dev));	blkdev_put(bdev, FMODE_READ);} ssize_t bl_pipe_downcall(struct file *filp, const char __user *src,			 size_t mlen){	struct nfs_net *nn = net_generic(filp->f_dentry->d_sb->s_fs_info,					 nfs_net_id); 	if (mlen != sizeof (struct bl_dev_msg))		return -EINVAL; 	if (copy_from_user(&nn->bl_mount_reply, src, mlen) != 0)		return -EFAULT; 	wake_up(&nn->bl_wq); 	return mlen;} void bl_pipe_destroy_msg(struct rpc_pipe_msg *msg){	struct bl_pipe_msg *bl_pipe_msg = container_of(msg, struct bl_pipe_msg, msg); 	if (msg->errno >= 0)		return;	wake_up(bl_pipe_msg->bl_wq);} /* * Decodes pnfs_block_deviceaddr4 which is XDR encoded in dev->dev_addr_buf. */struct pnfs_block_dev *nfs4_blk_decode_device(struct nfs_server *server,		       struct pnfs_device *dev){	struct pnfs_block_dev *rv;	struct block_device *bd = NULL;	struct bl_pipe_msg bl_pipe_msg;	struct rpc_pipe_msg *msg = &bl_pipe_msg.msg;	struct bl_msg_hdr bl_msg = {		.type = BL_DEVICE_MOUNT,		.totallen = dev->mincount,	};	uint8_t *dataptr;	DECLARE_WAITQUEUE(wq, current);	int offset, len, i, rc;	struct net *net = server->nfs_client->cl_net;	struct nfs_net *nn = net_generic(net, nfs_net_id);	struct bl_dev_msg *reply = &nn->bl_mount_reply; 	dprintk("%s CREATING PIPEFS MESSAGE\n", __func__);	dprintk("%s: deviceid: %s, mincount: %d\n", __func__, dev->dev_id.data,		dev->mincount); 	bl_pipe_msg.bl_wq = &nn->bl_wq;	memset(msg, 0, sizeof(*msg));	msg->data = kzalloc(sizeof(bl_msg) + dev->mincount, GFP_NOFS);	if (!msg->data) {		rv = ERR_PTR(-ENOMEM);		goto out;	} 	memcpy(msg->data, &bl_msg, sizeof(bl_msg));	dataptr = (uint8_t *) msg->data;	len = dev->mincount;	offset = sizeof(bl_msg);	for (i = 0; len > 0; i++) {		memcpy(&dataptr[offset], page_address(dev->pages[i]),				len < PAGE_CACHE_SIZE ? len : PAGE_CACHE_SIZE);		len -= PAGE_CACHE_SIZE;		offset += PAGE_CACHE_SIZE;	}	msg->len = sizeof(bl_msg) + dev->mincount; 	dprintk("%s CALLING USERSPACE DAEMON\n", __func__);	add_wait_queue(&nn->bl_wq, &wq);	rc = rpc_queue_upcall(nn->bl_device_pipe, msg);	if (rc < 0) {		remove_wait_queue(&nn->bl_wq, &wq);		rv = ERR_PTR(rc);		goto out;	} 	set_current_state(TASK_UNINTERRUPTIBLE);	schedule();	__set_current_state(TASK_RUNNING);	remove_wait_queue(&nn->bl_wq, &wq); 	if (reply->status != BL_DEVICE_REQUEST_PROC) {		dprintk("%s failed to open device: %d\n",			__func__, reply->status);		rv = ERR_PTR(-EINVAL);		goto out;	} 	bd = blkdev_get_by_dev(MKDEV(reply->major, reply->minor),			       FMODE_READ, NULL);	if (IS_ERR(bd)) {		dprintk("%s failed to open device : %ld\n", __func__,			PTR_ERR(bd));		rv = ERR_CAST(bd);		goto out;	} 	rv = kzalloc(sizeof(*rv), GFP_NOFS);	if (!rv) {		rv = ERR_PTR(-ENOMEM);		goto out;	} 	rv->bm_mdev = bd;	memcpy(&rv->bm_mdevid, &dev->dev_id, sizeof(struct nfs4_deviceid));	rv->net = net;	dprintk("%s Created device %s with bd_block_size %u\n",		__func__,		bd->bd_disk->disk_name,		bd->bd_block_size); out:	kfree(msg->data);	return rv;} /* Map deviceid returned by the server to constructed block_device */static struct block_device *translate_devid(struct pnfs_layout_hdr *lo,					    struct nfs4_deviceid *id){	struct block_device *rv = NULL;	struct block_mount_id *mid;	struct pnfs_block_dev *dev; 	dprintk("%s enter, lo=%p, id=%p\n", __func__, lo, id);	mid = BLK_ID(lo);	spin_lock(&mid->bm_lock);	list_for_each_entry(dev, &mid->bm_devlist, bm_node) {		if (memcmp(id->data, dev->bm_mdevid.data,			   NFS4_DEVICEID4_SIZE) == 0) {			rv = dev->bm_mdev;			goto out;		}	} out:	spin_unlock(&mid->bm_lock);	dprintk("%s returning %p\n", __func__, rv);	return rv;} /* Tracks info needed to ensure extents in layout obey constraints of spec */struct layout_verification {	u32 mode;	/* R or RW */	u64 start;	/* Expected start of next non-COW extent */	u64 inval;	/* Start of INVAL coverage */	u64 cowread;	/* End of COW read coverage */}; /* Verify the extent meets the layout requirements of the pnfs-block draft, * section 2.3.1. */static int verify_extent(struct pnfs_block_extent *be,			 struct layout_verification *lv){	if (lv->mode == IOMODE_READ) {		if (be->be_state == PNFS_BLOCK_READWRITE_DATA ||		    be->be_state == PNFS_BLOCK_INVALID_DATA)			return -EIO;		if (be->be_f_offset != lv->start)			return -EIO;		lv->start += be->be_length;		return 0;	}	/* lv->mode == IOMODE_RW */	if (be->be_state == PNFS_BLOCK_READWRITE_DATA) {		if (be->be_f_offset != lv->start)			return -EIO;		if (lv->cowread > lv->start)			return -EIO;		lv->start += be->be_length;		lv->inval = lv->start;		return 0;	} else if (be->be_state == PNFS_BLOCK_INVALID_DATA) {		if (be->be_f_offset != lv->start)			return -EIO;		lv->start += be->be_length;		return 0;	} else if (be->be_state == PNFS_BLOCK_READ_DATA) {		if (be->be_f_offset > lv->start)			return -EIO;		if (be->be_f_offset < lv->inval)			return -EIO;		if (be->be_f_offset < lv->cowread)			return -EIO;		/* It looks like you might want to min this with lv->start,		 * but you really don't.		 */		lv->inval = lv->inval + be->be_length;		lv->cowread = be->be_f_offset + be->be_length;		return 0;	} else		return -EIO;} /* XDR decode pnfs_block_layout4 structure */intnfs4_blk_process_layoutget(struct pnfs_layout_hdr *lo,			   struct nfs4_layoutget_res *lgr, gfp_t gfp_flags){	struct pnfs_block_layout *bl = BLK_LO2EXT(lo);	int i, status = -EIO;	uint32_t count;	struct pnfs_block_extent *be = NULL, *save;	struct xdr_stream stream;	struct xdr_buf buf;	struct page *scratch;	__be32 *p;	struct layout_verification lv = {		.mode = lgr->range.iomode,		.start = lgr->range.offset >> SECTOR_SHIFT,		.inval = lgr->range.offset >> SECTOR_SHIFT,		.cowread = lgr->range.offset >> SECTOR_SHIFT,	};	LIST_HEAD(extents); 	dprintk("---> %s\n", __func__); 	scratch = alloc_page(gfp_flags);	if (!scratch)		return -ENOMEM; 	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); 	p = xdr_inline_decode(&stream, 4);	if (unlikely(!p))		goto out_err; 	count = be32_to_cpup(p++); 	dprintk("%s enter, number of extents %i\n", __func__, count);	p = xdr_inline_decode(&stream, (28 + NFS4_DEVICEID4_SIZE) * count);	if (unlikely(!p))		goto out_err; 	/* Decode individual extents, putting them in temporary	 * staging area until whole layout is decoded to make error	 * recovery easier.	 */	for (i = 0; i < count; i++) {		be = bl_alloc_extent();		if (!be) {			status = -ENOMEM;			goto out_err;		}		memcpy(&be->be_devid, p, NFS4_DEVICEID4_SIZE);		p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);		be->be_mdev = translate_devid(lo, &be->be_devid);		if (!be->be_mdev)			goto out_err; 		/* The next three values are read in as bytes,		 * but stored as 512-byte sector lengths		 */		if (decode_sector_number(&p, &be->be_f_offset) < 0)			goto out_err;		if (decode_sector_number(&p, &be->be_length) < 0)			goto out_err;		if (decode_sector_number(&p, &be->be_v_offset) < 0)			goto out_err;		be->be_state = be32_to_cpup(p++);		if (be->be_state == PNFS_BLOCK_INVALID_DATA)			be->be_inval = &bl->bl_inval;		if (verify_extent(be, &lv)) {			dprintk("%s verify failed\n", __func__);			goto out_err;		}		list_add_tail(&be->be_node, &extents);	}	if (lgr->range.offset + lgr->range.length !=			lv.start << SECTOR_SHIFT) {		dprintk("%s Final length mismatch\n", __func__);		be = NULL;		goto out_err;	}	if (lv.start < lv.cowread) {		dprintk("%s Final uncovered COW extent\n", __func__);		be = NULL;		goto out_err;	}	/* Extents decoded properly, now try to merge them in to	 * existing layout extents.	 */	spin_lock(&bl->bl_ext_lock);	list_for_each_entry_safe(be, save, &extents, be_node) {		list_del(&be->be_node);		status = bl_add_merge_extent(bl, be);		if (status) {			spin_unlock(&bl->bl_ext_lock);			/* This is a fairly catastrophic error, as the			 * entire layout extent lists are now corrupted.			 * We should have some way to distinguish this.			 */			be = NULL;			goto out_err;		}	}	spin_unlock(&bl->bl_ext_lock);	status = 0; out:	__free_page(scratch);	dprintk("%s returns %i\n", __func__, status);	return status;  out_err:	bl_put_extent(be);	while (!list_empty(&extents)) {		be = list_first_entry(&extents, struct pnfs_block_extent,				      be_node);		list_del(&be->be_node);		bl_put_extent(be);	}	goto out;}