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