mirror_zfs/include/os/linux/zfs/sys/zfs_vfsops.h

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
 */

#ifndef	_SYS_FS_ZFS_VFSOPS_H
#define	_SYS_FS_ZFS_VFSOPS_H

#include <sys/dataset_kstats.h>
#include <sys/isa_defs.h>
#include <sys/types32.h>
#include <sys/list.h>
#include <sys/vfs.h>
#include <sys/zil.h>
#include <sys/sa.h>
#include <sys/rrwlock.h>
#include <sys/dsl_dataset.h>
#include <sys/zfs_ioctl.h>
#include <sys/objlist.h>

#ifdef	__cplusplus
extern "C" {
#endif

typedef struct zfsvfs zfsvfs_t;
struct znode;

/*
 * This structure emulates the vfs_t from other platforms.  It's purpose
 * is to facilitate the handling of mount options and minimize structural
 * differences between the platforms.
 */
typedef struct vfs {
	struct zfsvfs	*vfs_data;
	char		*vfs_mntpoint;	/* Primary mount point */
	uint64_t	vfs_xattr;
	boolean_t	vfs_readonly;
	boolean_t	vfs_do_readonly;
	boolean_t	vfs_setuid;
	boolean_t	vfs_do_setuid;
	boolean_t	vfs_exec;
	boolean_t	vfs_do_exec;
	boolean_t	vfs_devices;
	boolean_t	vfs_do_devices;
	boolean_t	vfs_do_xattr;
	boolean_t	vfs_atime;
	boolean_t	vfs_do_atime;
	boolean_t	vfs_relatime;
	boolean_t	vfs_do_relatime;
	boolean_t	vfs_nbmand;
	boolean_t	vfs_do_nbmand;
} vfs_t;

typedef struct zfs_mnt {
	const char	*mnt_osname;	/* Objset name */
	char		*mnt_data;	/* Raw mount options */
} zfs_mnt_t;

struct zfsvfs {
	vfs_t		*z_vfs;		/* generic fs struct */
	struct super_block *z_sb;	/* generic super_block */
	struct zfsvfs	*z_parent;	/* parent fs */
	objset_t	*z_os;		/* objset reference */
	uint64_t	z_flags;	/* super_block flags */
	uint64_t	z_root;		/* id of root znode */
	uint64_t	z_unlinkedobj;	/* id of unlinked zapobj */
	uint64_t	z_max_blksz;	/* maximum block size for files */
	uint64_t	z_fuid_obj;	/* fuid table object number */
	uint64_t	z_fuid_size;	/* fuid table size */
	avl_tree_t	z_fuid_idx;	/* fuid tree keyed by index */
	avl_tree_t	z_fuid_domain;	/* fuid tree keyed by domain */
	krwlock_t	z_fuid_lock;	/* fuid lock */
	boolean_t	z_fuid_loaded;	/* fuid tables are loaded */
	boolean_t	z_fuid_dirty;   /* need to sync fuid table ? */
	struct zfs_fuid_info	*z_fuid_replay; /* fuid info for replay */
	zilog_t		*z_log;		/* intent log pointer */
	uint_t		z_acl_inherit;	/* acl inheritance behavior */
	uint_t		z_acl_type;	/* type of ACL usable on this FS */
	zfs_case_t	z_case;		/* case-sense */
	boolean_t	z_utf8;		/* utf8-only */
	int		z_norm;		/* normalization flags */
	boolean_t	z_relatime;	/* enable relatime mount option */
	boolean_t	z_unmounted;	/* unmounted */
	rrmlock_t	z_teardown_lock;
	krwlock_t	z_teardown_inactive_lock;
	list_t		z_all_znodes;	/* all znodes in the fs */
	uint64_t	z_nr_znodes;	/* number of znodes in the fs */
	unsigned long	z_rollback_time; /* last online rollback time */
	unsigned long	z_snap_defer_time; /* last snapshot unmount deferral */
	kmutex_t	z_znodes_lock;	/* lock for z_all_znodes */
	arc_prune_t	*z_arc_prune;	/* called by ARC to prune caches */
	struct inode	*z_ctldir;	/* .zfs directory inode */
	boolean_t	z_show_ctldir;	/* expose .zfs in the root dir */
	boolean_t	z_issnap;	/* true if this is a snapshot */
	boolean_t	z_vscan;	/* virus scan on/off */
	boolean_t	z_use_fuids;	/* version allows fuids */
	boolean_t	z_replay;	/* set during ZIL replay */
	boolean_t	z_use_sa;	/* version allow system attributes */
	boolean_t	z_xattr_sa;	/* allow xattrs to be stores as SA */
	boolean_t	z_draining;	/* is true when drain is active */
	boolean_t	z_drain_cancel; /* signal the unlinked drain to stop */
	uint64_t	z_version;	/* ZPL version */
	uint64_t	z_shares_dir;	/* hidden shares dir */
	dataset_kstats_t	z_kstat;	/* fs kstats */
	kmutex_t	z_lock;
	uint64_t	z_userquota_obj;
	uint64_t	z_groupquota_obj;
	uint64_t	z_userobjquota_obj;
	uint64_t	z_groupobjquota_obj;
	uint64_t	z_projectquota_obj;
	uint64_t	z_projectobjquota_obj;
	uint64_t	z_replay_eof;	/* New end of file - replay only */
	sa_attr_type_t	*z_attr_table;	/* SA attr mapping->id */
	uint64_t	z_hold_size;	/* znode hold array size */
	avl_tree_t	*z_hold_trees;	/* znode hold trees */
	kmutex_t	*z_hold_locks;	/* znode hold locks */
	taskqid_t	z_drain_task;	/* task id for the unlink drain task */
};

#define	ZSB_XATTR	0x0001		/* Enable user xattrs */

/*
 * Allow a maximum number of links.  While ZFS does not internally limit
 * this the inode->i_nlink member is defined as an unsigned int.  To be
 * safe we use 2^31-1 as the limit.
 */
#define	ZFS_LINK_MAX		((1U << 31) - 1U)

/*
 * Normal filesystems (those not under .zfs/snapshot) have a total
 * file ID size limited to 12 bytes (including the length field) due to
 * NFSv2 protocol's limitation of 32 bytes for a filehandle.  For historical
 * reasons, this same limit is being imposed by the Solaris NFSv3 implementation
 * (although the NFSv3 protocol actually permits a maximum of 64 bytes).  It
 * is not possible to expand beyond 12 bytes without abandoning support
 * of NFSv2.
 *
 * For normal filesystems, we partition up the available space as follows:
 *	2 bytes		fid length (required)
 *	6 bytes		object number (48 bits)
 *	4 bytes		generation number (32 bits)
 *
 * We reserve only 48 bits for the object number, as this is the limit
 * currently defined and imposed by the DMU.
 */
typedef struct zfid_short {
	uint16_t	zf_len;
	uint8_t		zf_object[6];		/* obj[i] = obj >> (8 * i) */
	uint8_t		zf_gen[4];		/* gen[i] = gen >> (8 * i) */
} zfid_short_t;

/*
 * Filesystems under .zfs/snapshot have a total file ID size of 22 bytes
 * (including the length field).  This makes files under .zfs/snapshot
 * accessible by NFSv3 and NFSv4, but not NFSv2.
 *
 * For files under .zfs/snapshot, we partition up the available space
 * as follows:
 *	2 bytes		fid length (required)
 *	6 bytes		object number (48 bits)
 *	4 bytes		generation number (32 bits)
 *	6 bytes		objset id (48 bits)
 *	4 bytes		currently just zero (32 bits)
 *
 * We reserve only 48 bits for the object number and objset id, as these are
 * the limits currently defined and imposed by the DMU.
 */
typedef struct zfid_long {
	zfid_short_t	z_fid;
	uint8_t		zf_setid[6];		/* obj[i] = obj >> (8 * i) */
	uint8_t		zf_setgen[4];		/* gen[i] = gen >> (8 * i) */
} zfid_long_t;

#define	SHORT_FID_LEN	(sizeof (zfid_short_t) - sizeof (uint16_t))
#define	LONG_FID_LEN	(sizeof (zfid_long_t) - sizeof (uint16_t))

extern int zfs_suspend_fs(zfsvfs_t *zfsvfs);
extern int zfs_resume_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
extern int zfs_end_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
extern void zfs_exit_fs(zfsvfs_t *zfsvfs);
extern int zfs_set_version(zfsvfs_t *zfsvfs, uint64_t newvers);
extern int zfsvfs_create(const char *name, boolean_t readony, zfsvfs_t **zfvp);
extern int zfsvfs_create_impl(zfsvfs_t **zfvp, zfsvfs_t *zfsvfs, objset_t *os);
extern void zfsvfs_free(zfsvfs_t *zfsvfs);
extern int zfs_check_global_label(const char *dsname, const char *hexsl);

extern boolean_t zfs_is_readonly(zfsvfs_t *zfsvfs);
extern int zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent);
extern void zfs_preumount(struct super_block *sb);
extern int zfs_umount(struct super_block *sb);
extern int zfs_remount(struct super_block *sb, int *flags, zfs_mnt_t *zm);
extern int zfs_statvfs(struct dentry *dentry, struct kstatfs *statp);
extern int zfs_vget(struct super_block *sb, struct inode **ipp, fid_t *fidp);
extern int zfs_prune(struct super_block *sb, unsigned long nr_to_scan,
    int *objects);
extern int zfs_get_temporary_prop(dsl_dataset_t *ds, zfs_prop_t zfs_prop,
    uint64_t *val, char *setpoint);

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_FS_ZFS_VFSOPS_H */