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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Simple zone file system for zoned block devices.
4 *
5 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
6 */
7#ifndef __ZONEFS_H__
8#define __ZONEFS_H__
9
10#include <linux/fs.h>
11#include <linux/magic.h>
12#include <linux/uuid.h>
13#include <linux/mutex.h>
14#include <linux/rwsem.h>
15#include <linux/kobject.h>
16
17/*
18 * Maximum length of file names: this only needs to be large enough to fit
19 * the zone group directory names and a decimal zone number for file names.
20 * 16 characters is plenty.
21 */
22#define ZONEFS_NAME_MAX 16
23
24/*
25 * Zone types: ZONEFS_ZTYPE_SEQ is used for all sequential zone types
26 * defined in linux/blkzoned.h, that is, BLK_ZONE_TYPE_SEQWRITE_REQ and
27 * BLK_ZONE_TYPE_SEQWRITE_PREF.
28 */
29enum zonefs_ztype {
30 ZONEFS_ZTYPE_CNV,
31 ZONEFS_ZTYPE_SEQ,
32 ZONEFS_ZTYPE_MAX,
33};
34
35static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
36{
37 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
38 return ZONEFS_ZTYPE_CNV;
39 return ZONEFS_ZTYPE_SEQ;
40}
41
42#define ZONEFS_ZONE_OPEN (1 << 0)
43#define ZONEFS_ZONE_ACTIVE (1 << 1)
44
45/*
46 * In-memory inode data.
47 */
48struct zonefs_inode_info {
49 struct inode i_vnode;
50
51 /* File zone type */
52 enum zonefs_ztype i_ztype;
53
54 /* File zone start sector (512B unit) */
55 sector_t i_zsector;
56
57 /* File zone write pointer position (sequential zones only) */
58 loff_t i_wpoffset;
59
60 /* File maximum size */
61 loff_t i_max_size;
62
63 /* File zone size */
64 loff_t i_zone_size;
65
66 /*
67 * To serialise fully against both syscall and mmap based IO and
68 * sequential file truncation, two locks are used. For serializing
69 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
70 * file truncate operations against block mapping, i_truncate_mutex is
71 * used. i_truncate_mutex also protects against concurrent accesses
72 * and changes to the inode private data, and in particular changes to
73 * a sequential file size on completion of direct IO writes.
74 * Serialization of mmap read IOs with truncate and syscall IO
75 * operations is done with invalidate_lock in addition to
76 * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock
77 * (invalidate_lock first, i_truncate_mutex second).
78 */
79 struct mutex i_truncate_mutex;
80
81 /* guarded by i_truncate_mutex */
82 unsigned int i_wr_refcnt;
83 unsigned int i_flags;
84};
85
86static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
87{
88 return container_of(inode, struct zonefs_inode_info, i_vnode);
89}
90
91/*
92 * On-disk super block (block 0).
93 */
94#define ZONEFS_LABEL_LEN 64
95#define ZONEFS_UUID_SIZE 16
96#define ZONEFS_SUPER_SIZE 4096
97
98struct zonefs_super {
99
100 /* Magic number */
101 __le32 s_magic;
102
103 /* Checksum */
104 __le32 s_crc;
105
106 /* Volume label */
107 char s_label[ZONEFS_LABEL_LEN];
108
109 /* 128-bit uuid */
110 __u8 s_uuid[ZONEFS_UUID_SIZE];
111
112 /* Features */
113 __le64 s_features;
114
115 /* UID/GID to use for files */
116 __le32 s_uid;
117 __le32 s_gid;
118
119 /* File permissions */
120 __le32 s_perm;
121
122 /* Padding to ZONEFS_SUPER_SIZE bytes */
123 __u8 s_reserved[3988];
124
125} __packed;
126
127/*
128 * Feature flags: specified in the s_features field of the on-disk super
129 * block struct zonefs_super and in-memory in the s_feartures field of
130 * struct zonefs_sb_info.
131 */
132enum zonefs_features {
133 /*
134 * Aggregate contiguous conventional zones into a single file.
135 */
136 ZONEFS_F_AGGRCNV = 1ULL << 0,
137 /*
138 * Use super block specified UID for files instead of default 0.
139 */
140 ZONEFS_F_UID = 1ULL << 1,
141 /*
142 * Use super block specified GID for files instead of default 0.
143 */
144 ZONEFS_F_GID = 1ULL << 2,
145 /*
146 * Use super block specified file permissions instead of default 640.
147 */
148 ZONEFS_F_PERM = 1ULL << 3,
149};
150
151#define ZONEFS_F_DEFINED_FEATURES \
152 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
153
154/*
155 * Mount options for zone write pointer error handling.
156 */
157#define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */
158#define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */
159#define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */
160#define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */
161#define ZONEFS_MNTOPT_ERRORS_MASK \
162 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
163 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
164#define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */
165
166/*
167 * In-memory Super block information.
168 */
169struct zonefs_sb_info {
170
171 unsigned long s_mount_opts;
172
173 spinlock_t s_lock;
174
175 unsigned long long s_features;
176 kuid_t s_uid;
177 kgid_t s_gid;
178 umode_t s_perm;
179 uuid_t s_uuid;
180 unsigned int s_zone_sectors_shift;
181
182 unsigned int s_nr_files[ZONEFS_ZTYPE_MAX];
183
184 loff_t s_blocks;
185 loff_t s_used_blocks;
186
187 unsigned int s_max_wro_seq_files;
188 atomic_t s_wro_seq_files;
189
190 unsigned int s_max_active_seq_files;
191 atomic_t s_active_seq_files;
192
193 bool s_sysfs_registered;
194 struct kobject s_kobj;
195 struct completion s_kobj_unregister;
196};
197
198static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
199{
200 return sb->s_fs_info;
201}
202
203#define zonefs_info(sb, format, args...) \
204 pr_info("zonefs (%s): " format, sb->s_id, ## args)
205#define zonefs_err(sb, format, args...) \
206 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
207#define zonefs_warn(sb, format, args...) \
208 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
209
210int zonefs_sysfs_register(struct super_block *sb);
211void zonefs_sysfs_unregister(struct super_block *sb);
212int zonefs_sysfs_init(void);
213void zonefs_sysfs_exit(void);
214
215#endif