summaryrefslogtreecommitdiff
path: root/fs/zonefs/zonefs.h
blob: 8175652241b5c4104748d8a75fcbd59e58ef1e88 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Simple zone file system for zoned block devices.
 *
 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
 */
#ifndef __ZONEFS_H__
#define __ZONEFS_H__

#include <linux/fs.h>
#include <linux/magic.h>
#include <linux/uuid.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/kobject.h>

/*
 * Maximum length of file names: this only needs to be large enough to fit
 * the zone group directory names and a decimal zone number for file names.
 * 16 characters is plenty.
 */
#define ZONEFS_NAME_MAX		16

/*
 * Zone types: ZONEFS_ZTYPE_SEQ is used for all sequential zone types
 * defined in linux/blkzoned.h, that is, BLK_ZONE_TYPE_SEQWRITE_REQ and
 * BLK_ZONE_TYPE_SEQWRITE_PREF.
 */
enum zonefs_ztype {
	ZONEFS_ZTYPE_CNV,
	ZONEFS_ZTYPE_SEQ,
	ZONEFS_ZTYPE_MAX,
};

static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
{
	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
		return ZONEFS_ZTYPE_CNV;
	return ZONEFS_ZTYPE_SEQ;
}

#define ZONEFS_ZONE_INIT_MODE	(1U << 0)
#define ZONEFS_ZONE_OPEN	(1U << 1)
#define ZONEFS_ZONE_ACTIVE	(1U << 2)
#define ZONEFS_ZONE_OFFLINE	(1U << 3)
#define ZONEFS_ZONE_READONLY	(1U << 4)
#define ZONEFS_ZONE_CNV		(1U << 31)

/*
 * In-memory per-file inode zone data.
 */
struct zonefs_zone {
	/* Zone state flags */
	unsigned int		z_flags;

	/* Zone start sector (512B unit) */
	sector_t		z_sector;

	/* Zone size (bytes) */
	loff_t			z_size;

	/* Zone capacity (file maximum size, bytes) */
	loff_t			z_capacity;

	/* Write pointer offset in the zone (sequential zones only, bytes) */
	loff_t			z_wpoffset;

	/* Saved inode uid, gid and access rights */
	umode_t			z_mode;
	kuid_t			z_uid;
	kgid_t			z_gid;
};

/*
 * In memory zone group information: all zones of a group are exposed
 * as files, one file per zone.
 */
struct zonefs_zone_group {
	struct inode		*g_inode;
	unsigned int		g_nr_zones;
	struct zonefs_zone	*g_zones;
};

/*
 * In-memory inode data.
 */
struct zonefs_inode_info {
	struct inode		i_vnode;

	/*
	 * To serialise fully against both syscall and mmap based IO and
	 * sequential file truncation, two locks are used. For serializing
	 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
	 * file truncate operations against block mapping, i_truncate_mutex is
	 * used. i_truncate_mutex also protects against concurrent accesses
	 * and changes to the inode private data, and in particular changes to
	 * a sequential file size on completion of direct IO writes.
	 * Serialization of mmap read IOs with truncate and syscall IO
	 * operations is done with invalidate_lock in addition to
	 * i_truncate_mutex.  Only zonefs_seq_file_truncate() takes both lock
	 * (invalidate_lock first, i_truncate_mutex second).
	 */
	struct mutex		i_truncate_mutex;

	/* guarded by i_truncate_mutex */
	unsigned int		i_wr_refcnt;
};

static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
{
	return container_of(inode, struct zonefs_inode_info, i_vnode);
}

static inline bool zonefs_zone_is_cnv(struct zonefs_zone *z)
{
	return z->z_flags & ZONEFS_ZONE_CNV;
}

static inline bool zonefs_zone_is_seq(struct zonefs_zone *z)
{
	return !zonefs_zone_is_cnv(z);
}

static inline struct zonefs_zone *zonefs_inode_zone(struct inode *inode)
{
	return inode->i_private;
}

static inline bool zonefs_inode_is_cnv(struct inode *inode)
{
	return zonefs_zone_is_cnv(zonefs_inode_zone(inode));
}

static inline bool zonefs_inode_is_seq(struct inode *inode)
{
	return zonefs_zone_is_seq(zonefs_inode_zone(inode));
}

/*
 * On-disk super block (block 0).
 */
#define ZONEFS_LABEL_LEN	64
#define ZONEFS_UUID_SIZE	16
#define ZONEFS_SUPER_SIZE	4096

struct zonefs_super {

	/* Magic number */
	__le32		s_magic;

	/* Checksum */
	__le32		s_crc;

	/* Volume label */
	char		s_label[ZONEFS_LABEL_LEN];

	/* 128-bit uuid */
	__u8		s_uuid[ZONEFS_UUID_SIZE];

	/* Features */
	__le64		s_features;

	/* UID/GID to use for files */
	__le32		s_uid;
	__le32		s_gid;

	/* File permissions */
	__le32		s_perm;

	/* Padding to ZONEFS_SUPER_SIZE bytes */
	__u8		s_reserved[3988];

} __packed;

/*
 * Feature flags: specified in the s_features field of the on-disk super
 * block struct zonefs_super and in-memory in the s_feartures field of
 * struct zonefs_sb_info.
 */
enum zonefs_features {
	/*
	 * Aggregate contiguous conventional zones into a single file.
	 */
	ZONEFS_F_AGGRCNV = 1ULL << 0,
	/*
	 * Use super block specified UID for files instead of default 0.
	 */
	ZONEFS_F_UID = 1ULL << 1,
	/*
	 * Use super block specified GID for files instead of default 0.
	 */
	ZONEFS_F_GID = 1ULL << 2,
	/*
	 * Use super block specified file permissions instead of default 640.
	 */
	ZONEFS_F_PERM = 1ULL << 3,
};

#define ZONEFS_F_DEFINED_FEATURES \
	(ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)

/*
 * Mount options for zone write pointer error handling.
 */
#define ZONEFS_MNTOPT_ERRORS_RO		(1 << 0) /* Make zone file readonly */
#define ZONEFS_MNTOPT_ERRORS_ZRO	(1 << 1) /* Make zone file offline */
#define ZONEFS_MNTOPT_ERRORS_ZOL	(1 << 2) /* Make zone file offline */
#define ZONEFS_MNTOPT_ERRORS_REPAIR	(1 << 3) /* Remount read-only */
#define ZONEFS_MNTOPT_ERRORS_MASK	\
	(ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
	 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
#define ZONEFS_MNTOPT_EXPLICIT_OPEN	(1 << 4) /* Explicit open/close of zones on open/close */

/*
 * In-memory Super block information.
 */
struct zonefs_sb_info {

	unsigned long		s_mount_opts;

	spinlock_t		s_lock;

	unsigned long long	s_features;
	kuid_t			s_uid;
	kgid_t			s_gid;
	umode_t			s_perm;
	uuid_t			s_uuid;
	unsigned int		s_zone_sectors_shift;

	struct zonefs_zone_group s_zgroup[ZONEFS_ZTYPE_MAX];

	loff_t			s_blocks;
	loff_t			s_used_blocks;

	unsigned int		s_max_wro_seq_files;
	atomic_t		s_wro_seq_files;

	unsigned int		s_max_active_seq_files;
	atomic_t		s_active_seq_files;

	bool			s_sysfs_registered;
	struct kobject		s_kobj;
	struct completion	s_kobj_unregister;
};

static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

#define zonefs_info(sb, format, args...)	\
	pr_info("zonefs (%s): " format, sb->s_id, ## args)
#define zonefs_err(sb, format, args...)		\
	pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
#define zonefs_warn(sb, format, args...)	\
	pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)

/* In super.c */
void zonefs_inode_account_active(struct inode *inode);
int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op);
void zonefs_i_size_write(struct inode *inode, loff_t isize);
void zonefs_update_stats(struct inode *inode, loff_t new_isize);
void __zonefs_io_error(struct inode *inode, bool write);

static inline void zonefs_io_error(struct inode *inode, bool write)
{
	struct zonefs_inode_info *zi = ZONEFS_I(inode);

	mutex_lock(&zi->i_truncate_mutex);
	__zonefs_io_error(inode, write);
	mutex_unlock(&zi->i_truncate_mutex);
}

/* In super.c */
extern const struct inode_operations zonefs_dir_inode_operations;
extern const struct file_operations zonefs_dir_operations;

/* In file.c */
extern const struct address_space_operations zonefs_file_aops;
extern const struct file_operations zonefs_file_operations;
int zonefs_file_truncate(struct inode *inode, loff_t isize);

/* In sysfs.c */
int zonefs_sysfs_register(struct super_block *sb);
void zonefs_sysfs_unregister(struct super_block *sb);
int zonefs_sysfs_init(void);
void zonefs_sysfs_exit(void);

#endif