[linux-2.6-block.git] / fs / nfsd / nfsfh.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 *
 * This file describes the layout of the file handles as passed
 * over the wire.
 */
#ifndef _LINUX_NFSD_NFSFH_H
#define _LINUX_NFSD_NFSFH_H

#include <linux/crc32.h>
#include <linux/sunrpc/svc.h>
#include <uapi/linux/nfsd/nfsfh.h>
#include <linux/iversion.h>

static inline __u32 ino_t_to_u32(ino_t ino)
{
	return (__u32) ino;
}

static inline ino_t u32_to_ino_t(__u32 uino)
{
	return (ino_t) uino;
}

/*
 * This is the internal representation of an NFS handle used in knfsd.
 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
 */
typedef struct svc_fh {
	struct knfsd_fh		fh_handle;	/* FH data */
	int			fh_maxsize;	/* max size for fh_handle */
	struct dentry *		fh_dentry;	/* validated dentry */
	struct svc_export *	fh_export;	/* export pointer */

	bool			fh_locked;	/* inode locked by us */
	bool			fh_want_write;	/* remount protection taken */

#ifdef CONFIG_NFSD_V3
	bool			fh_post_saved;	/* post-op attrs saved */
	bool			fh_pre_saved;	/* pre-op attrs saved */

	/* Pre-op attributes saved during fh_lock */
	__u64			fh_pre_size;	/* size before operation */
	struct timespec		fh_pre_mtime;	/* mtime before oper */
	struct timespec		fh_pre_ctime;	/* ctime before oper */
	/*
	 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
	 *  to find out if it is valid.
	 */
	u64			fh_pre_change;

	/* Post-op attributes saved in fh_unlock */
	struct kstat		fh_post_attr;	/* full attrs after operation */
	u64			fh_post_change; /* nfsv4 change; see above */
#endif /* CONFIG_NFSD_V3 */

} svc_fh;

enum nfsd_fsid {
	FSID_DEV = 0,
	FSID_NUM,
	FSID_MAJOR_MINOR,
	FSID_ENCODE_DEV,
	FSID_UUID4_INUM,
	FSID_UUID8,
	FSID_UUID16,
	FSID_UUID16_INUM,
};

enum fsid_source {
	FSIDSOURCE_DEV,
	FSIDSOURCE_FSID,
	FSIDSOURCE_UUID,
};
extern enum fsid_source fsid_source(struct svc_fh *fhp);


/*
 * This might look a little large to "inline" but in all calls except
 * one, 'vers' is constant so moste of the function disappears.
 *
 * In some cases the values are considered to be host endian and in
 * others, net endian. fsidv is always considered to be u32 as the
 * callers don't know which it will be. So we must use __force to keep
 * sparse from complaining. Since these values are opaque to the
 * client, that shouldn't be a problem.
 */
static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
			   u32 fsid, unsigned char *uuid)
{
	u32 *up;
	switch(vers) {
	case FSID_DEV:
		fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
				 MINOR(dev));
		fsidv[1] = ino_t_to_u32(ino);
		break;
	case FSID_NUM:
		fsidv[0] = fsid;
		break;
	case FSID_MAJOR_MINOR:
		fsidv[0] = (__force __u32)htonl(MAJOR(dev));
		fsidv[1] = (__force __u32)htonl(MINOR(dev));
		fsidv[2] = ino_t_to_u32(ino);
		break;

	case FSID_ENCODE_DEV:
		fsidv[0] = new_encode_dev(dev);
		fsidv[1] = ino_t_to_u32(ino);
		break;

	case FSID_UUID4_INUM:
		/* 4 byte fsid and inode number */
		up = (u32*)uuid;
		fsidv[0] = ino_t_to_u32(ino);
		fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
		break;

	case FSID_UUID8:
		/* 8 byte fsid  */
		up = (u32*)uuid;
		fsidv[0] = up[0] ^ up[2];
		fsidv[1] = up[1] ^ up[3];
		break;

	case FSID_UUID16:
		/* 16 byte fsid - NFSv3+ only */
		memcpy(fsidv, uuid, 16);
		break;

	case FSID_UUID16_INUM:
		/* 8 byte inode and 16 byte fsid */
		*(u64*)fsidv = (u64)ino;
		memcpy(fsidv+2, uuid, 16);
		break;
	default: BUG();
	}
}

static inline int key_len(int type)
{
	switch(type) {
	case FSID_DEV:		return 8;
	case FSID_NUM: 		return 4;
	case FSID_MAJOR_MINOR:	return 12;
	case FSID_ENCODE_DEV:	return 8;
	case FSID_UUID4_INUM:	return 8;
	case FSID_UUID8:	return 8;
	case FSID_UUID16:	return 16;
	case FSID_UUID16_INUM:	return 24;
	default: return 0;
	}
}

/*
 * Shorthand for dprintk()'s
 */
extern char * SVCFH_fmt(struct svc_fh *fhp);

/*
 * Function prototypes
 */
__be32	fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
__be32	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
__be32	fh_update(struct svc_fh *);
void	fh_put(struct svc_fh *);

static __inline__ struct svc_fh *
fh_copy(struct svc_fh *dst, struct svc_fh *src)
{
	WARN_ON(src->fh_dentry || src->fh_locked);
			
	*dst = *src;
	return dst;
}

static inline void
fh_copy_shallow(struct knfsd_fh *dst, struct knfsd_fh *src)
{
	dst->fh_size = src->fh_size;
	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
}

static __inline__ struct svc_fh *
fh_init(struct svc_fh *fhp, int maxsize)
{
	memset(fhp, 0, sizeof(*fhp));
	fhp->fh_maxsize = maxsize;
	return fhp;
}

static inline bool fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
{
	if (fh1->fh_size != fh2->fh_size)
		return false;
	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
		return false;
	return true;
}

static inline bool fh_fsid_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
{
	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
		return false;
	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
		return false;
	return true;
}

#ifdef CONFIG_CRC32
/**
 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
 * @fh - pointer to filehandle
 *
 * returns a crc32 hash for the filehandle that is compatible with
 * the one displayed by "wireshark".
 */

static inline u32
knfsd_fh_hash(struct knfsd_fh *fh)
{
	return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
}
#else
static inline u32
knfsd_fh_hash(struct knfsd_fh *fh)
{
	return 0;
}
#endif

#ifdef CONFIG_NFSD_V3
/*
 * The wcc data stored in current_fh should be cleared
 * between compound ops.
 */
static inline void
fh_clear_wcc(struct svc_fh *fhp)
{
	fhp->fh_post_saved = false;
	fhp->fh_pre_saved = false;
}

/*
 * We could use i_version alone as the change attribute.  However,
 * i_version can go backwards after a reboot.  On its own that doesn't
 * necessarily cause a problem, but if i_version goes backwards and then
 * is incremented again it could reuse a value that was previously used
 * before boot, and a client who queried the two values might
 * incorrectly assume nothing changed.
 *
 * By using both ctime and the i_version counter we guarantee that as
 * long as time doesn't go backwards we never reuse an old value.
 */
static inline u64 nfsd4_change_attribute(struct kstat *stat,
					 struct inode *inode)
{
	u64 chattr;

	chattr =  stat->ctime.tv_sec;
	chattr <<= 30;
	chattr += stat->ctime.tv_nsec;
	chattr += inode_query_iversion(inode);
	return chattr;
}

extern void fill_pre_wcc(struct svc_fh *fhp);
extern void fill_post_wcc(struct svc_fh *fhp);
#else
#define fh_clear_wcc(ignored)
#define fill_pre_wcc(ignored)
#define fill_post_wcc(notused)
#endif /* CONFIG_NFSD_V3 */


/*
 * Lock a file handle/inode
 * NOTE: both fh_lock and fh_unlock are done "by hand" in
 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
 * so, any changes here should be reflected there.
 */

static inline void
fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
{
	struct dentry	*dentry = fhp->fh_dentry;
	struct inode	*inode;

	BUG_ON(!dentry);

	if (fhp->fh_locked) {
		printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
			dentry);
		return;
	}

	inode = d_inode(dentry);
	inode_lock_nested(inode, subclass);
	fill_pre_wcc(fhp);
	fhp->fh_locked = true;
}

static inline void
fh_lock(struct svc_fh *fhp)
{
	fh_lock_nested(fhp, I_MUTEX_NORMAL);
}

/*
 * Unlock a file handle/inode
 */
static inline void
fh_unlock(struct svc_fh *fhp)
{
	if (fhp->fh_locked) {
		fill_post_wcc(fhp);
		inode_unlock(d_inode(fhp->fh_dentry));
		fhp->fh_locked = false;
	}
}

#endif /* _LINUX_NFSD_NFSFH_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
9c69de4c CH	2	/*
	3	* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
	4	*
	5	* This file describes the layout of the file handles as passed
	6	* over the wire.
	7	*/
	8	#ifndef _LINUX_NFSD_NFSFH_H
	9	#define _LINUX_NFSD_NFSFH_H
	10
6e8b50d1	11	#include <linux/crc32.h>
9c69de4c CH	12	#include <linux/sunrpc/svc.h>
9c69de4c CH	13	#include <uapi/linux/nfsd/nfsfh.h>
1f15a550	14	#include <linux/iversion.h>
9c69de4c CH	15
	16	static inline __u32 ino_t_to_u32(ino_t ino)
	17	{
	18	return (__u32) ino;
	19	}
	20
	21	static inline ino_t u32_to_ino_t(__u32 uino)
	22	{
	23	return (ino_t) uino;
	24	}
1557aca7	25
9c69de4c CH	26	/*
	27	* This is the internal representation of an NFS handle used in knfsd.
	28	* pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
	29	*/
	30	typedef struct svc_fh {
	31	struct knfsd_fh fh_handle; /* FH data */
fcaba026	32	int fh_maxsize; /* max size for fh_handle */
9c69de4c CH	33	struct dentry * fh_dentry; /* validated dentry */
9c69de4c CH	34	struct svc_export * fh_export; /* export pointer */
9c69de4c	35
aaf91ec1 JL	36	bool fh_locked; /* inode locked by us */
aaf91ec1 JL	37	bool fh_want_write; /* remount protection taken */
9c69de4c CH	38
9c69de4c CH	39	#ifdef CONFIG_NFSD_V3
aaf91ec1 JL	40	bool fh_post_saved; /* post-op attrs saved */
aaf91ec1 JL	41	bool fh_pre_saved; /* pre-op attrs saved */
9c69de4c CH	42
	43	/* Pre-op attributes saved during fh_lock */
	44	__u64 fh_pre_size; /* size before operation */
	45	struct timespec fh_pre_mtime; /* mtime before oper */
	46	struct timespec fh_pre_ctime; /* ctime before oper */
	47	/*
	48	* pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
	49	* to find out if it is valid.
	50	*/
	51	u64 fh_pre_change;
	52
	53	/* Post-op attributes saved in fh_unlock */
	54	struct kstat fh_post_attr; /* full attrs after operation */
	55	u64 fh_post_change; /* nfsv4 change; see above */
	56	#endif /* CONFIG_NFSD_V3 */
1557aca7	57
9c69de4c	58	} svc_fh;
1557aca7 BF	59
	60	enum nfsd_fsid {
	61	FSID_DEV = 0,
	62	FSID_NUM,
	63	FSID_MAJOR_MINOR,
	64	FSID_ENCODE_DEV,
	65	FSID_UUID4_INUM,
	66	FSID_UUID8,
	67	FSID_UUID16,
	68	FSID_UUID16_INUM,
	69	};
	70
	71	enum fsid_source {
	72	FSIDSOURCE_DEV,
	73	FSIDSOURCE_FSID,
	74	FSIDSOURCE_UUID,
	75	};
	76	extern enum fsid_source fsid_source(struct svc_fh *fhp);
	77
	78
94ec938b JL	79	/*
94ec938b JL	80	* This might look a little large to "inline" but in all calls except
1557aca7	81	* one, 'vers' is constant so moste of the function disappears.
94ec938b JL	82	*
	83	* In some cases the values are considered to be host endian and in
	84	* others, net endian. fsidv is always considered to be u32 as the
	85	* callers don't know which it will be. So we must use __force to keep
	86	* sparse from complaining. Since these values are opaque to the
	87	* client, that shouldn't be a problem.
1557aca7 BF	88	*/
	89	static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
	90	u32 fsid, unsigned char *uuid)
	91	{
	92	u32 *up;
	93	switch(vers) {
	94	case FSID_DEV:
94ec938b	95	fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) \|
1557aca7 BF	96	MINOR(dev));
	97	fsidv[1] = ino_t_to_u32(ino);
	98	break;
	99	case FSID_NUM:
	100	fsidv[0] = fsid;
	101	break;
	102	case FSID_MAJOR_MINOR:
94ec938b JL	103	fsidv[0] = (__force __u32)htonl(MAJOR(dev));
94ec938b JL	104	fsidv[1] = (__force __u32)htonl(MINOR(dev));
1557aca7 BF	105	fsidv[2] = ino_t_to_u32(ino);
	106	break;
	107
	108	case FSID_ENCODE_DEV:
	109	fsidv[0] = new_encode_dev(dev);
	110	fsidv[1] = ino_t_to_u32(ino);
	111	break;
	112
	113	case FSID_UUID4_INUM:
	114	/* 4 byte fsid and inode number */
	115	up = (u32*)uuid;
	116	fsidv[0] = ino_t_to_u32(ino);
	117	fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
	118	break;
	119
	120	case FSID_UUID8:
	121	/* 8 byte fsid */
	122	up = (u32*)uuid;
	123	fsidv[0] = up[0] ^ up[2];
	124	fsidv[1] = up[1] ^ up[3];
	125	break;
	126
	127	case FSID_UUID16:
	128	/* 16 byte fsid - NFSv3+ only */
	129	memcpy(fsidv, uuid, 16);
	130	break;
	131
	132	case FSID_UUID16_INUM:
	133	/* 8 byte inode and 16 byte fsid */
	134	(u64)fsidv = (u64)ino;
	135	memcpy(fsidv+2, uuid, 16);
	136	break;
	137	default: BUG();
	138	}
	139	}
	140
	141	static inline int key_len(int type)
	142	{
	143	switch(type) {
	144	case FSID_DEV: return 8;
	145	case FSID_NUM: return 4;
	146	case FSID_MAJOR_MINOR: return 12;
	147	case FSID_ENCODE_DEV: return 8;
	148	case FSID_UUID4_INUM: return 8;
	149	case FSID_UUID8: return 8;
	150	case FSID_UUID16: return 16;
	151	case FSID_UUID16_INUM: return 24;
	152	default: return 0;
	153	}
	154	}
	155
	156	/*
	157	* Shorthand for dprintk()'s
	158	*/
	159	extern char * SVCFH_fmt(struct svc_fh *fhp);
	160
	161	/*
	162	* Function prototypes
	163	*/
175a4eb7	164	__be32 fh_verify(struct svc_rqst , struct svc_fh , umode_t, int);
1557aca7 BF	165	__be32 fh_compose(struct svc_fh , struct svc_export , struct dentry , struct svc_fh );
	166	__be32 fh_update(struct svc_fh *);
	167	void fh_put(struct svc_fh *);
	168
	169	static __inline__ struct svc_fh *
	170	fh_copy(struct svc_fh dst, struct svc_fh src)
	171	{
	172	WARN_ON(src->fh_dentry \|\| src->fh_locked);
	173
	174	dst = src;
	175	return dst;
	176	}
	177
	178	static inline void
	179	fh_copy_shallow(struct knfsd_fh dst, struct knfsd_fh src)
	180	{
	181	dst->fh_size = src->fh_size;
	182	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
	183	}
	184
	185	static __inline__ struct svc_fh *
	186	fh_init(struct svc_fh *fhp, int maxsize)
	187	{
	188	memset(fhp, 0, sizeof(*fhp));
	189	fhp->fh_maxsize = maxsize;
	190	return fhp;
	191	}
	192
4d94c2ef CH	193	static inline bool fh_match(struct knfsd_fh fh1, struct knfsd_fh fh2)
	194	{
	195	if (fh1->fh_size != fh2->fh_size)
	196	return false;
	197	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
	198	return false;
	199	return true;
	200	}
	201
9558f250 CH	202	static inline bool fh_fsid_match(struct knfsd_fh fh1, struct knfsd_fh fh2)
	203	{
	204	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
	205	return false;
0ab39de6	206	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
9558f250 CH	207	return false;
	208	return true;
	209	}
	210
6e8b50d1 JL	211	#ifdef CONFIG_CRC32
	212	/**
	213	* knfsd_fh_hash - calculate the crc32 hash for the filehandle
	214	* @fh - pointer to filehandle
	215	*
	216	* returns a crc32 hash for the filehandle that is compatible with
	217	* the one displayed by "wireshark".
	218	*/
	219
	220	static inline u32
	221	knfsd_fh_hash(struct knfsd_fh *fh)
	222	{
	223	return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
	224	}
	225	#else
	226	static inline u32
	227	knfsd_fh_hash(struct knfsd_fh *fh)
	228	{
	229	return 0;
	230	}
	231	#endif
	232
1557aca7	233	#ifdef CONFIG_NFSD_V3
2336745e KM	234	/*
	235	* The wcc data stored in current_fh should be cleared
	236	* between compound ops.
	237	*/
	238	static inline void
	239	fh_clear_wcc(struct svc_fh *fhp)
	240	{
aaf91ec1 JL	241	fhp->fh_post_saved = false;
aaf91ec1 JL	242	fhp->fh_pre_saved = false;
2336745e KM	243	}
2336745e KM	244
630458e7 BF	245	/*
	246	* We could use i_version alone as the change attribute. However,
	247	* i_version can go backwards after a reboot. On its own that doesn't
	248	* necessarily cause a problem, but if i_version goes backwards and then
	249	* is incremented again it could reuse a value that was previously used
	250	* before boot, and a client who queried the two values might
	251	* incorrectly assume nothing changed.
	252	*
	253	* By using both ctime and the i_version counter we guarantee that as
	254	* long as time doesn't go backwards we never reuse an old value.
	255	*/
39ca1bf6 AG	256	static inline u64 nfsd4_change_attribute(struct kstat *stat,
39ca1bf6 AG	257	struct inode *inode)
630458e7 BF	258	{
	259	u64 chattr;
	260
39ca1bf6	261	chattr = stat->ctime.tv_sec;
630458e7	262	chattr <<= 30;
39ca1bf6	263	chattr += stat->ctime.tv_nsec;
1f15a550	264	chattr += inode_query_iversion(inode);
630458e7 BF	265	return chattr;
	266	}
	267
39ca1bf6 AG	268	extern void fill_pre_wcc(struct svc_fh *fhp);
39ca1bf6 AG	269	extern void fill_post_wcc(struct svc_fh *fhp);
1557aca7	270	#else
2336745e KM	271	#define fh_clear_wcc(ignored)
2336745e KM	272	#define fill_pre_wcc(ignored)
1557aca7 BF	273	#define fill_post_wcc(notused)
	274	#endif /* CONFIG_NFSD_V3 */
	275
	276
	277	/*
	278	* Lock a file handle/inode
	279	* NOTE: both fh_lock and fh_unlock are done "by hand" in
	280	* vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
	281	* so, any changes here should be reflected there.
	282	*/
	283
	284	static inline void
	285	fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
	286	{
	287	struct dentry *dentry = fhp->fh_dentry;
	288	struct inode *inode;
	289
	290	BUG_ON(!dentry);
	291
	292	if (fhp->fh_locked) {
a6a9f18f AV	293	printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
a6a9f18f AV	294	dentry);
1557aca7 BF	295	return;
	296	}
	297
2b0143b5	298	inode = d_inode(dentry);
5955102c	299	inode_lock_nested(inode, subclass);
1557aca7	300	fill_pre_wcc(fhp);
aaf91ec1	301	fhp->fh_locked = true;
1557aca7 BF	302	}
	303
	304	static inline void
	305	fh_lock(struct svc_fh *fhp)
	306	{
	307	fh_lock_nested(fhp, I_MUTEX_NORMAL);
	308	}
	309
	310	/*
	311	* Unlock a file handle/inode
	312	*/
	313	static inline void
	314	fh_unlock(struct svc_fh *fhp)
	315	{
1557aca7 BF	316	if (fhp->fh_locked) {
1557aca7 BF	317	fill_post_wcc(fhp);
5955102c	318	inode_unlock(d_inode(fhp->fh_dentry));
aaf91ec1	319	fhp->fh_locked = false;
1557aca7 BF	320	}
	321	}
	322
9c69de4c	323	#endif /* _LINUX_NFSD_NFSFH_H */