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