blocklayout.c
/*
* Copyright (c) 2014 Christoph Hellwig.
*/
#include <linux/exportfs.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/nfsd/debug.h>
#include "blocklayoutxdr.h"
#include "pnfs.h"
#define NFSDDBG_FACILITY NFSDDBG_PNFS
static int
nfsd4_block_get_device_info_simple(struct super_block *sb,
struct nfsd4_getdeviceinfo *gdp)
{
struct pnfs_block_deviceaddr *dev;
struct pnfs_block_volume *b;
dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
sizeof(struct pnfs_block_volume), GFP_KERNEL);
if (!dev)
return -ENOMEM;
gdp->gd_device = dev;
dev->nr_volumes = 1;
b = &dev->volumes[0];
b->type = PNFS_BLOCK_VOLUME_SIMPLE;
b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
&b->simple.offset);
}
static __be32
nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
struct nfsd4_getdeviceinfo *gdp)
{
if (sb->s_bdev != sb->s_bdev->bd_contains)
return nfserr_inval;
return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
}
static __be32
nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
struct nfsd4_layoutget *args)
{
struct nfsd4_layout_seg *seg = &args->lg_seg;
struct super_block *sb = inode->i_sb;
u32 block_size = (1 << inode->i_blkbits);
struct pnfs_block_extent *bex;
struct iomap iomap;
u32 device_generation = 0;
int error;
/*
* We do not attempt to support I/O smaller than the fs block size,
* or not aligned to it.
*/
if (args->lg_minlength < block_size) {
dprintk("pnfsd: I/O too small\n");
goto out_layoutunavailable;
}
if (seg->offset & (block_size - 1)) {
dprintk("pnfsd: I/O misaligned\n");
goto out_layoutunavailable;
}
/*
* Some clients barf on non-zero block numbers for NONE or INVALID
* layouts, so make sure to zero the whole structure.
*/
error = -ENOMEM;
bex = kzalloc(sizeof(*bex), GFP_KERNEL);
if (!bex)
goto out_error;
args->lg_content = bex;
error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
&iomap, seg->iomode != IOMODE_READ,
&device_generation);
if (error) {
if (error == -ENXIO)
goto out_layoutunavailable;
goto out_error;
}
if (iomap.length < args->lg_minlength) {
dprintk("pnfsd: extent smaller than minlength\n");
goto out_layoutunavailable;
}
switch (iomap.type) {
case IOMAP_MAPPED:
if (seg->iomode == IOMODE_READ)
bex->es = PNFS_BLOCK_READ_DATA;
else
bex->es = PNFS_BLOCK_READWRITE_DATA;
bex->soff = (iomap.blkno << 9);
break;
case IOMAP_UNWRITTEN:
if (seg->iomode & IOMODE_RW) {
/*
* Crack monkey special case from section 2.3.1.
*/
if (args->lg_minlength == 0) {
dprintk("pnfsd: no soup for you!\n");
goto out_layoutunavailable;
}
bex->es = PNFS_BLOCK_INVALID_DATA;
bex->soff = (iomap.blkno << 9);
break;
}
/*FALLTHRU*/
case IOMAP_HOLE:
if (seg->iomode == IOMODE_READ) {
bex->es = PNFS_BLOCK_NONE_DATA;
break;
}
/*FALLTHRU*/
case IOMAP_DELALLOC:
default:
WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
goto out_layoutunavailable;
}
error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
if (error)
goto out_error;
bex->foff = iomap.offset;
bex->len = iomap.length;
seg->offset = iomap.offset;
seg->length = iomap.length;
dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
return 0;
out_error:
seg->length = 0;
return nfserrno(error);
out_layoutunavailable:
seg->length = 0;
return nfserr_layoutunavailable;
}
static __be32
nfsd4_block_proc_layoutcommit(struct inode *inode,
struct nfsd4_layoutcommit *lcp)
{
loff_t new_size = lcp->lc_last_wr + 1;
struct iattr iattr = { .ia_valid = 0 };
struct iomap *iomaps;
int nr_iomaps;
int error;
nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
if (nr_iomaps < 0)
return nfserrno(nr_iomaps);
if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
lcp->lc_mtime = current_fs_time(inode->i_sb);
iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
if (new_size > i_size_read(inode)) {
iattr.ia_valid |= ATTR_SIZE;
iattr.ia_size = new_size;
}
error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
nr_iomaps, &iattr);
kfree(iomaps);
return nfserrno(error);
}
const struct nfsd4_layout_ops bl_layout_ops = {
/*
* Pretend that we send notification to the client. This is a blatant
* lie to force recent Linux clients to cache our device IDs.
* We rarely ever change the device ID, so the harm of leaking deviceids
* for a while isn't too bad. Unfortunately RFC5661 is a complete mess
* in this regard, but I filed errata 4119 for this a while ago, and
* hopefully the Linux client will eventually start caching deviceids
* without this again.
*/
.notify_types =
NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
.proc_getdeviceinfo = nfsd4_block_proc_getdeviceinfo,
.encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo,
.proc_layoutget = nfsd4_block_proc_layoutget,
.encode_layoutget = nfsd4_block_encode_layoutget,
.proc_layoutcommit = nfsd4_block_proc_layoutcommit,
};