fs/nfsd/flexfilelayoutxdr.c

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

File Facts

System
Linux kernel
Corpus path
fs/nfsd/flexfilelayoutxdr.c
Extension
.c
Size
2968 bytes
Lines
125
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

struct ff_idmap {
	char buf[11];
	int len;
};

__be32
nfsd4_ff_encode_layoutget(struct xdr_stream *xdr,
		const struct nfsd4_layoutget *lgp)
{
	const struct pnfs_ff_layout *fl = lgp->lg_content;
	int len, mirror_len, ds_len, fh_len;
	__be32 *p;

	/*
	 * Unlike nfsd4_encode_user, we know these will
	 * always be stringified.
	 */
	struct ff_idmap uid;
	struct ff_idmap gid;

	fh_len = 4 + fl->fh.size;

	uid.len = sprintf(uid.buf, "%u", from_kuid(&init_user_ns, fl->uid));
	gid.len = sprintf(gid.buf, "%u", from_kgid(&init_user_ns, fl->gid));

	/* 8 + len for recording the length, name, and padding */
	ds_len = 20 + sizeof(stateid_opaque_t) + 4 + fh_len +
		 8 + uid.len + 8 + gid.len;

	mirror_len = 4 + ds_len;

	/* The layout segment */
	len = 20 + mirror_len;

	p = xdr_reserve_space(xdr, sizeof(__be32) + len);
	if (!p)
		return nfserr_toosmall;

	*p++ = cpu_to_be32(len);
	p = xdr_encode_hyper(p, 0);		/* stripe unit of 1 */

	*p++ = cpu_to_be32(1);			/* single mirror */
	*p++ = cpu_to_be32(1);			/* single data server */

	p = svcxdr_encode_deviceid4(p, &fl->deviceid);

	*p++ = cpu_to_be32(1);			/* efficiency */

	*p++ = cpu_to_be32(fl->stateid.si_generation);
	p = xdr_encode_opaque_fixed(p, &fl->stateid.si_opaque,
				    sizeof(stateid_opaque_t));

	*p++ = cpu_to_be32(1);			/* single file handle */
	p = xdr_encode_opaque(p, fl->fh.data, fl->fh.size);

	p = xdr_encode_opaque(p, uid.buf, uid.len);
	p = xdr_encode_opaque(p, gid.buf, gid.len);

	*p++ = cpu_to_be32(fl->flags);
	*p++ = cpu_to_be32(0);			/* No stats collect hint */

	return 0;
}

__be32
nfsd4_ff_encode_getdeviceinfo(struct xdr_stream *xdr,
		const struct nfsd4_getdeviceinfo *gdp)
{
	struct pnfs_ff_device_addr *da = gdp->gd_device;
	int len;
	int ver_len;
	int addr_len;
	__be32 *p;

	/*
	 * See paragraph 5 of RFC 8881 S18.40.3.
	 */
	if (!gdp->gd_maxcount) {
		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
			return nfserr_resource;
		return nfs_ok;
	}

	/* len + padding for two strings */
	addr_len = 16 + da->netaddr.netid_len + da->netaddr.addr_len;
	ver_len = 20;

	len = 4 + ver_len + 4 + addr_len;

	p = xdr_reserve_space(xdr, len + sizeof(__be32));

Annotation

Implementation Notes