| /* |
| * 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; |
| } |
| |
| /* Open a block_device by device number. */ |
| struct block_device *nfs4_blkdev_get(dev_t dev) |
| { |
| struct block_device *bd; |
| |
| dprintk("%s enter\n", __func__); |
| bd = blkdev_get_by_dev(dev, FMODE_READ, NULL); |
| if (IS_ERR(bd)) |
| goto fail; |
| return bd; |
| fail: |
| dprintk("%s failed to open device : %ld\n", |
| __func__, PTR_ERR(bd)); |
| return NULL; |
| } |
| |
| /* |
| * Release the block device |
| */ |
| int nfs4_blkdev_put(struct block_device *bdev) |
| { |
| dprintk("%s for device %d:%d\n", __func__, MAJOR(bdev->bd_dev), |
| MINOR(bdev->bd_dev)); |
| return 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->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 = nfs4_blkdev_get(MKDEV(reply->major, reply->minor)); |
| if (IS_ERR(bd)) { |
| rc = PTR_ERR(bd); |
| dprintk("%s failed to open device : %d\n", __func__, rc); |
| rv = ERR_PTR(rc); |
| 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 */ |
| int |
| nfs4_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; |
| } |