fs/nfsd/flexfilelayout.c

Source file repositories/reference/linux-study-clean/fs/nfsd/flexfilelayout.c

File Facts

System
Linux kernel
Corpus path
fs/nfsd/flexfilelayout.c
Extension
.c
Size
3693 bytes
Lines
145
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
 *
 * The following implements a super-simple flex-file server
 * where the NFSv4.1 mds is also the ds. And the storage is
 * the same. I.e., writing to the mds via a NFSv4.1 WRITE
 * goes to the same location as the NFSv3 WRITE.
 */
#include <linux/slab.h>

#include <linux/nfsd/debug.h>

#include <linux/sunrpc/addr.h>

#include "flexfilelayoutxdr.h"
#include "pnfs.h"
#include "vfs.h"

#define NFSDDBG_FACILITY	NFSDDBG_PNFS

static __be32
nfsd4_ff_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode,
		const struct svc_fh *fhp, struct nfsd4_layoutget *args)
{
	struct nfsd4_layout_seg *seg = &args->lg_seg;
	u32 device_generation = 0;
	int error;
	uid_t u;

	struct pnfs_ff_layout *fl;

	/*
	 * The super simple flex file server has 1 mirror, 1 data server,
	 * and 1 file handle. So instead of 4 allocs, do 1 for now.
	 * Zero it out for the stateid - don't want junk in there!
	 */
	error = -ENOMEM;
	fl = kzalloc_obj(*fl);
	if (!fl)
		goto out_error;
	args->lg_content = fl;

	/*
	 * Avoid layout commit, try to force the I/O to the DS,
	 * and for fun, cause all IOMODE_RW layout segments to
	 * effectively be WRITE only.
	 */
	fl->flags = FF_FLAGS_NO_LAYOUTCOMMIT | FF_FLAGS_NO_IO_THRU_MDS |
		    FF_FLAGS_NO_READ_IO;

	/* Do not allow a IOMODE_READ segment to have write pemissions */
	if (seg->iomode == IOMODE_READ) {
		u = from_kuid(&init_user_ns, inode->i_uid) + 1;
		fl->uid = make_kuid(&init_user_ns, u);
	} else
		fl->uid = inode->i_uid;
	fl->gid = inode->i_gid;

	error = nfsd4_set_deviceid(&fl->deviceid, fhp, device_generation);
	if (error)
		goto out_error;

	fl->fh.size = fhp->fh_handle.fh_size;
	memcpy(fl->fh.data, &fhp->fh_handle.fh_raw, fl->fh.size);

	/* Give whole file layout segments */
	seg->offset = 0;
	seg->length = NFS4_MAX_UINT64;

	dprintk("GET: 0x%llx:0x%llx %d\n", seg->offset, seg->length,
		seg->iomode);
	return 0;

out_error:
	seg->length = 0;
	return nfserrno(error);
}

static __be32
nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
		struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp)
{
	struct pnfs_ff_device_addr *da;

	u16 port;
	char addr[INET6_ADDRSTRLEN];

	da = kzalloc_obj(struct pnfs_ff_device_addr);
	if (!da)

Annotation

Implementation Notes