- 根目录:
- fs
- nfs
- blocklayout
- blocklayoutdev.c
/*
* 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;
}