[mirror_ubuntu-focal-kernel.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>

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 inode *inode)
{
	u64 chattr;

	chattr =  inode->i_ctime.tv_sec;
	chattr <<= 30;
	chattr += inode->i_ctime.tv_nsec;
	chattr += inode->i_version;
	return chattr;
}

/*
 * Fill in the pre_op attr for the wcc data
 */
static inline void
fill_pre_wcc(struct svc_fh *fhp)
{
	struct inode    *inode;

	inode = d_inode(fhp->fh_dentry);
	if (!fhp->fh_pre_saved) {
		fhp->fh_pre_mtime = inode->i_mtime;
		fhp->fh_pre_ctime = inode->i_ctime;
		fhp->fh_pre_size  = inode->i_size;
		fhp->fh_pre_change = nfsd4_change_attribute(inode);
		fhp->fh_pre_saved = true;
	}
}

extern void fill_post_wcc(struct svc_fh *);
#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>
	13	#include <uapi/linux/nfsd/nfsfh.h>
	14
	15	static inline __u32 ino_t_to_u32(ino_t ino)
	16	{
	17	return (__u32) ino;
	18	}
	19
	20	static inline ino_t u32_to_ino_t(__u32 uino)
	21	{
	22	return (ino_t) uino;
	23	}
1557aca7	24
9c69de4c CH	25	/*
	26	* This is the internal representation of an NFS handle used in knfsd.
	27	* pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
	28	*/
	29	typedef struct svc_fh {
	30	struct knfsd_fh fh_handle; /* FH data */
fcaba026	31	int fh_maxsize; /* max size for fh_handle */
9c69de4c CH	32	struct dentry * fh_dentry; /* validated dentry */
9c69de4c CH	33	struct svc_export * fh_export; /* export pointer */
9c69de4c	34
aaf91ec1 JL	35	bool fh_locked; /* inode locked by us */
aaf91ec1 JL	36	bool fh_want_write; /* remount protection taken */
9c69de4c CH	37
9c69de4c CH	38	#ifdef CONFIG_NFSD_V3
aaf91ec1 JL	39	bool fh_post_saved; /* post-op attrs saved */
aaf91ec1 JL	40	bool fh_pre_saved; /* pre-op attrs saved */
9c69de4c CH	41
	42	/* Pre-op attributes saved during fh_lock */
	43	__u64 fh_pre_size; /* size before operation */
	44	struct timespec fh_pre_mtime; /* mtime before oper */
	45	struct timespec fh_pre_ctime; /* ctime before oper */
	46	/*
	47	* pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
	48	* to find out if it is valid.
	49	*/
	50	u64 fh_pre_change;
	51
	52	/* Post-op attributes saved in fh_unlock */
	53	struct kstat fh_post_attr; /* full attrs after operation */
	54	u64 fh_post_change; /* nfsv4 change; see above */
	55	#endif /* CONFIG_NFSD_V3 */
1557aca7	56
9c69de4c	57	} svc_fh;
1557aca7 BF	58
	59	enum nfsd_fsid {
	60	FSID_DEV = 0,
	61	FSID_NUM,
	62	FSID_MAJOR_MINOR,
	63	FSID_ENCODE_DEV,
	64	FSID_UUID4_INUM,
	65	FSID_UUID8,
	66	FSID_UUID16,
	67	FSID_UUID16_INUM,
	68	};
	69
	70	enum fsid_source {
	71	FSIDSOURCE_DEV,
	72	FSIDSOURCE_FSID,
	73	FSIDSOURCE_UUID,
	74	};
	75	extern enum fsid_source fsid_source(struct svc_fh *fhp);
	76
	77
94ec938b JL	78	/*
94ec938b JL	79	* This might look a little large to "inline" but in all calls except
1557aca7	80	* one, 'vers' is constant so moste of the function disappears.
94ec938b JL	81	*
	82	* In some cases the values are considered to be host endian and in
	83	* others, net endian. fsidv is always considered to be u32 as the
	84	* callers don't know which it will be. So we must use __force to keep
	85	* sparse from complaining. Since these values are opaque to the
	86	* client, that shouldn't be a problem.
1557aca7 BF	87	*/
	88	static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
	89	u32 fsid, unsigned char *uuid)
	90	{
	91	u32 *up;
	92	switch(vers) {
	93	case FSID_DEV:
94ec938b	94	fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) \|
1557aca7 BF	95	MINOR(dev));
	96	fsidv[1] = ino_t_to_u32(ino);
	97	break;
	98	case FSID_NUM:
	99	fsidv[0] = fsid;
	100	break;
	101	case FSID_MAJOR_MINOR:
94ec938b JL	102	fsidv[0] = (__force __u32)htonl(MAJOR(dev));
94ec938b JL	103	fsidv[1] = (__force __u32)htonl(MINOR(dev));
1557aca7 BF	104	fsidv[2] = ino_t_to_u32(ino);
	105	break;
	106
	107	case FSID_ENCODE_DEV:
	108	fsidv[0] = new_encode_dev(dev);
	109	fsidv[1] = ino_t_to_u32(ino);
	110	break;
	111
	112	case FSID_UUID4_INUM:
	113	/* 4 byte fsid and inode number */
	114	up = (u32*)uuid;
	115	fsidv[0] = ino_t_to_u32(ino);
	116	fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
	117	break;
	118
	119	case FSID_UUID8:
	120	/* 8 byte fsid */
	121	up = (u32*)uuid;
	122	fsidv[0] = up[0] ^ up[2];
	123	fsidv[1] = up[1] ^ up[3];
	124	break;
	125
	126	case FSID_UUID16:
	127	/* 16 byte fsid - NFSv3+ only */
	128	memcpy(fsidv, uuid, 16);
	129	break;
	130
	131	case FSID_UUID16_INUM:
	132	/* 8 byte inode and 16 byte fsid */
	133	(u64)fsidv = (u64)ino;
	134	memcpy(fsidv+2, uuid, 16);
	135	break;
	136	default: BUG();
	137	}
	138	}
	139
	140	static inline int key_len(int type)
	141	{
	142	switch(type) {
	143	case FSID_DEV: return 8;
	144	case FSID_NUM: return 4;
	145	case FSID_MAJOR_MINOR: return 12;
	146	case FSID_ENCODE_DEV: return 8;
	147	case FSID_UUID4_INUM: return 8;
	148	case FSID_UUID8: return 8;
	149	case FSID_UUID16: return 16;
	150	case FSID_UUID16_INUM: return 24;
	151	default: return 0;
	152	}
	153	}
	154
	155	/*
	156	* Shorthand for dprintk()'s
	157	*/
	158	extern char * SVCFH_fmt(struct svc_fh *fhp);
	159
	160	/*
	161	* Function prototypes
	162	*/
175a4eb7	163	__be32 fh_verify(struct svc_rqst , struct svc_fh , umode_t, int);
1557aca7 BF	164	__be32 fh_compose(struct svc_fh , struct svc_export , struct dentry , struct svc_fh );
	165	__be32 fh_update(struct svc_fh *);
	166	void fh_put(struct svc_fh *);
	167
	168	static __inline__ struct svc_fh *
	169	fh_copy(struct svc_fh dst, struct svc_fh src)
	170	{
	171	WARN_ON(src->fh_dentry \|\| src->fh_locked);
	172
	173	dst = src;
	174	return dst;
	175	}
	176
	177	static inline void
	178	fh_copy_shallow(struct knfsd_fh dst, struct knfsd_fh src)
	179	{
	180	dst->fh_size = src->fh_size;
	181	memcpy(&dst->fh_base, &src->fh_base, src->fh_size);
	182	}
	183
	184	static __inline__ struct svc_fh *
	185	fh_init(struct svc_fh *fhp, int maxsize)
	186	{
	187	memset(fhp, 0, sizeof(*fhp));
	188	fhp->fh_maxsize = maxsize;
	189	return fhp;
	190	}
	191
4d94c2ef CH	192	static inline bool fh_match(struct knfsd_fh fh1, struct knfsd_fh fh2)
	193	{
	194	if (fh1->fh_size != fh2->fh_size)
	195	return false;
	196	if (memcmp(fh1->fh_base.fh_pad, fh2->fh_base.fh_pad, fh1->fh_size) != 0)
	197	return false;
	198	return true;
	199	}
	200
9558f250 CH	201	static inline bool fh_fsid_match(struct knfsd_fh fh1, struct knfsd_fh fh2)
	202	{
	203	if (fh1->fh_fsid_type != fh2->fh_fsid_type)
	204	return false;
0ab39de6	205	if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0)
9558f250 CH	206	return false;
	207	return true;
	208	}
	209
6e8b50d1 JL	210	#ifdef CONFIG_CRC32
	211	/**
	212	* knfsd_fh_hash - calculate the crc32 hash for the filehandle
	213	* @fh - pointer to filehandle
	214	*
	215	* returns a crc32 hash for the filehandle that is compatible with
	216	* the one displayed by "wireshark".
	217	*/
	218
	219	static inline u32
	220	knfsd_fh_hash(struct knfsd_fh *fh)
	221	{
	222	return ~crc32_le(0xFFFFFFFF, (unsigned char *)&fh->fh_base, fh->fh_size);
	223	}
	224	#else
	225	static inline u32
	226	knfsd_fh_hash(struct knfsd_fh *fh)
	227	{
	228	return 0;
	229	}
	230	#endif
	231
1557aca7	232	#ifdef CONFIG_NFSD_V3
2336745e KM	233	/*
	234	* The wcc data stored in current_fh should be cleared
	235	* between compound ops.
	236	*/
	237	static inline void
	238	fh_clear_wcc(struct svc_fh *fhp)
	239	{
aaf91ec1 JL	240	fhp->fh_post_saved = false;
aaf91ec1 JL	241	fhp->fh_pre_saved = false;
2336745e KM	242	}
2336745e KM	243
630458e7 BF	244	/*
	245	* We could use i_version alone as the change attribute. However,
	246	* i_version can go backwards after a reboot. On its own that doesn't
	247	* necessarily cause a problem, but if i_version goes backwards and then
	248	* is incremented again it could reuse a value that was previously used
	249	* before boot, and a client who queried the two values might
	250	* incorrectly assume nothing changed.
	251	*
	252	* By using both ctime and the i_version counter we guarantee that as
	253	* long as time doesn't go backwards we never reuse an old value.
	254	*/
	255	static inline u64 nfsd4_change_attribute(struct inode *inode)
	256	{
	257	u64 chattr;
	258
	259	chattr = inode->i_ctime.tv_sec;
	260	chattr <<= 30;
	261	chattr += inode->i_ctime.tv_nsec;
	262	chattr += inode->i_version;
	263	return chattr;
	264	}
	265
1557aca7 BF	266	/*
	267	* Fill in the pre_op attr for the wcc data
	268	*/
	269	static inline void
	270	fill_pre_wcc(struct svc_fh *fhp)
	271	{
	272	struct inode *inode;
	273
2b0143b5	274	inode = d_inode(fhp->fh_dentry);
1557aca7 BF	275	if (!fhp->fh_pre_saved) {
	276	fhp->fh_pre_mtime = inode->i_mtime;
	277	fhp->fh_pre_ctime = inode->i_ctime;
	278	fhp->fh_pre_size = inode->i_size;
630458e7	279	fhp->fh_pre_change = nfsd4_change_attribute(inode);
aaf91ec1	280	fhp->fh_pre_saved = true;
1557aca7 BF	281	}
	282	}
	283
	284	extern void fill_post_wcc(struct svc_fh *);
	285	#else
2336745e KM	286	#define fh_clear_wcc(ignored)
2336745e KM	287	#define fill_pre_wcc(ignored)
1557aca7 BF	288	#define fill_post_wcc(notused)
	289	#endif /* CONFIG_NFSD_V3 */
	290
	291
	292	/*
	293	* Lock a file handle/inode
	294	* NOTE: both fh_lock and fh_unlock are done "by hand" in
	295	* vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
	296	* so, any changes here should be reflected there.
	297	*/
	298
	299	static inline void
	300	fh_lock_nested(struct svc_fh *fhp, unsigned int subclass)
	301	{
	302	struct dentry *dentry = fhp->fh_dentry;
	303	struct inode *inode;
	304
	305	BUG_ON(!dentry);
	306
	307	if (fhp->fh_locked) {
a6a9f18f AV	308	printk(KERN_WARNING "fh_lock: %pd2 already locked!\n",
a6a9f18f AV	309	dentry);
1557aca7 BF	310	return;
	311	}
	312
2b0143b5	313	inode = d_inode(dentry);
5955102c	314	inode_lock_nested(inode, subclass);
1557aca7	315	fill_pre_wcc(fhp);
aaf91ec1	316	fhp->fh_locked = true;
1557aca7 BF	317	}
	318
	319	static inline void
	320	fh_lock(struct svc_fh *fhp)
	321	{
	322	fh_lock_nested(fhp, I_MUTEX_NORMAL);
	323	}
	324
	325	/*
	326	* Unlock a file handle/inode
	327	*/
	328	static inline void
	329	fh_unlock(struct svc_fh *fhp)
	330	{
1557aca7 BF	331	if (fhp->fh_locked) {
1557aca7 BF	332	fill_post_wcc(fhp);
5955102c	333	inode_unlock(d_inode(fhp->fh_dentry));
aaf91ec1	334	fhp->fh_locked = false;
1557aca7 BF	335	}
	336	}
	337
9c69de4c	338	#endif /* _LINUX_NFSD_NFSFH_H */