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 */
29 enum zonefs_ztype {
30 ZONEFS_ZTYPE_CNV,
31 ZONEFS_ZTYPE_SEQ,
32 ZONEFS_ZTYPE_MAX,
33 };
34
35 static 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_INIT_MODE (1U << 0)
43 #define ZONEFS_ZONE_OPEN (1U << 1)
44 #define ZONEFS_ZONE_ACTIVE (1U << 2)
45 #define ZONEFS_ZONE_OFFLINE (1U << 3)
46 #define ZONEFS_ZONE_READONLY (1U << 4)
47 #define ZONEFS_ZONE_CNV (1U << 31)
48
49 /*
50 * In-memory per-file inode zone data.
51 */
52 struct zonefs_zone {
53 /* Zone state flags */
54 unsigned int z_flags;
55
56 /* Zone start sector (512B unit) */
57 sector_t z_sector;
58
59 /* Zone size (bytes) */
60 loff_t z_size;
61
62 /* Zone capacity (file maximum size, bytes) */
63 loff_t z_capacity;
64
65 /* Write pointer offset in the zone (sequential zones only, bytes) */
66 loff_t z_wpoffset;
67
68 /* Saved inode uid, gid and access rights */
69 umode_t z_mode;
70 kuid_t z_uid;
71 kgid_t z_gid;
72 };
73
74 /*
75 * In memory zone group information: all zones of a group are exposed
76 * as files, one file per zone.
77 */
78 struct zonefs_zone_group {
79 struct inode *g_inode;
80 unsigned int g_nr_zones;
81 struct zonefs_zone *g_zones;
82 };
83
84 /*
85 * In-memory inode data.
86 */
87 struct zonefs_inode_info {
88 struct inode i_vnode;
89
90 /*
91 * To serialise fully against both syscall and mmap based IO and
92 * sequential file truncation, two locks are used. For serializing
93 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
94 * file truncate operations against block mapping, i_truncate_mutex is
95 * used. i_truncate_mutex also protects against concurrent accesses
96 * and changes to the inode private data, and in particular changes to
97 * a sequential file size on completion of direct IO writes.
98 * Serialization of mmap read IOs with truncate and syscall IO
99 * operations is done with invalidate_lock in addition to
100 * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock
101 * (invalidate_lock first, i_truncate_mutex second).
102 */
103 struct mutex i_truncate_mutex;
104
105 /* guarded by i_truncate_mutex */
106 unsigned int i_wr_refcnt;
107 };
108
109 static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
110 {
111 return container_of(inode, struct zonefs_inode_info, i_vnode);
112 }
113
114 static inline bool zonefs_zone_is_cnv(struct zonefs_zone *z)
115 {
116 return z->z_flags & ZONEFS_ZONE_CNV;
117 }
118
119 static inline bool zonefs_zone_is_seq(struct zonefs_zone *z)
120 {
121 return !zonefs_zone_is_cnv(z);
122 }
123
124 static inline struct zonefs_zone *zonefs_inode_zone(struct inode *inode)
125 {
126 return inode->i_private;
127 }
128
129 static inline bool zonefs_inode_is_cnv(struct inode *inode)
130 {
131 return zonefs_zone_is_cnv(zonefs_inode_zone(inode));
132 }
133
134 static inline bool zonefs_inode_is_seq(struct inode *inode)
135 {
136 return zonefs_zone_is_seq(zonefs_inode_zone(inode));
137 }
138
139 /*
140 * On-disk super block (block 0).
141 */
142 #define ZONEFS_LABEL_LEN 64
143 #define ZONEFS_UUID_SIZE 16
144 #define ZONEFS_SUPER_SIZE 4096
145
146 struct zonefs_super {
147
148 /* Magic number */
149 __le32 s_magic;
150
151 /* Checksum */
152 __le32 s_crc;
153
154 /* Volume label */
155 char s_label[ZONEFS_LABEL_LEN];
156
157 /* 128-bit uuid */
158 __u8 s_uuid[ZONEFS_UUID_SIZE];
159
160 /* Features */
161 __le64 s_features;
162
163 /* UID/GID to use for files */
164 __le32 s_uid;
165 __le32 s_gid;
166
167 /* File permissions */
168 __le32 s_perm;
169
170 /* Padding to ZONEFS_SUPER_SIZE bytes */
171 __u8 s_reserved[3988];
172
173 } __packed;
174
175 /*
176 * Feature flags: specified in the s_features field of the on-disk super
177 * block struct zonefs_super and in-memory in the s_feartures field of
178 * struct zonefs_sb_info.
179 */
180 enum zonefs_features {
181 /*
182 * Aggregate contiguous conventional zones into a single file.
183 */
184 ZONEFS_F_AGGRCNV = 1ULL << 0,
185 /*
186 * Use super block specified UID for files instead of default 0.
187 */
188 ZONEFS_F_UID = 1ULL << 1,
189 /*
190 * Use super block specified GID for files instead of default 0.
191 */
192 ZONEFS_F_GID = 1ULL << 2,
193 /*
194 * Use super block specified file permissions instead of default 640.
195 */
196 ZONEFS_F_PERM = 1ULL << 3,
197 };
198
199 #define ZONEFS_F_DEFINED_FEATURES \
200 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
201
202 /*
203 * Mount options for zone write pointer error handling.
204 */
205 #define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */
206 #define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */
207 #define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */
208 #define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */
209 #define ZONEFS_MNTOPT_ERRORS_MASK \
210 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
211 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
212 #define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */
213
214 /*
215 * In-memory Super block information.
216 */
217 struct zonefs_sb_info {
218
219 unsigned long s_mount_opts;
220
221 spinlock_t s_lock;
222
223 unsigned long long s_features;
224 kuid_t s_uid;
225 kgid_t s_gid;
226 umode_t s_perm;
227 uuid_t s_uuid;
228 unsigned int s_zone_sectors_shift;
229
230 struct zonefs_zone_group s_zgroup[ZONEFS_ZTYPE_MAX];
231
232 loff_t s_blocks;
233 loff_t s_used_blocks;
234
235 unsigned int s_max_wro_seq_files;
236 atomic_t s_wro_seq_files;
237
238 unsigned int s_max_active_seq_files;
239 atomic_t s_active_seq_files;
240
241 bool s_sysfs_registered;
242 struct kobject s_kobj;
243 struct completion s_kobj_unregister;
244 };
245
246 static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
247 {
248 return sb->s_fs_info;
249 }
250
251 #define zonefs_info(sb, format, args...) \
252 pr_info("zonefs (%s): " format, sb->s_id, ## args)
253 #define zonefs_err(sb, format, args...) \
254 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
255 #define zonefs_warn(sb, format, args...) \
256 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
257
258 /* In super.c */
259 void zonefs_inode_account_active(struct inode *inode);
260 int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op);
261 void zonefs_i_size_write(struct inode *inode, loff_t isize);
262 void zonefs_update_stats(struct inode *inode, loff_t new_isize);
263 void __zonefs_io_error(struct inode *inode, bool write);
264
265 static inline void zonefs_io_error(struct inode *inode, bool write)
266 {
267 struct zonefs_inode_info *zi = ZONEFS_I(inode);
268
269 mutex_lock(&zi->i_truncate_mutex);
270 __zonefs_io_error(inode, write);
271 mutex_unlock(&zi->i_truncate_mutex);
272 }
273
274 /* In super.c */
275 extern const struct inode_operations zonefs_dir_inode_operations;
276 extern const struct file_operations zonefs_dir_operations;
277
278 /* In file.c */
279 extern const struct address_space_operations zonefs_file_aops;
280 extern const struct file_operations zonefs_file_operations;
281 int zonefs_file_truncate(struct inode *inode, loff_t isize);
282
283 /* In sysfs.c */
284 int zonefs_sysfs_register(struct super_block *sb);
285 void zonefs_sysfs_unregister(struct super_block *sb);
286 int zonefs_sysfs_init(void);
287 void zonefs_sysfs_exit(void);
288
289 #endif
290
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