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_OPEN (1U << 0) 43 #define ZONEFS_ZONE_ACTIVE (1U << 1) 44 #define ZONEFS_ZONE_OFFLINE (1U << 2) 45 #define ZONEFS_ZONE_READONLY (1U << 3) 46 47 /* 48 * In-memory inode data. 49 */ 50 struct zonefs_inode_info { 51 struct inode i_vnode; 52 53 /* File zone type */ 54 enum zonefs_ztype i_ztype; 55 56 /* File zone start sector (512B unit) */ 57 sector_t i_zsector; 58 59 /* File zone write pointer position (sequential zones only) */ 60 loff_t i_wpoffset; 61 62 /* File maximum size */ 63 loff_t i_max_size; 64 65 /* File zone size */ 66 loff_t i_zone_size; 67 68 /* 69 * To serialise fully against both syscall and mmap based IO and 70 * sequential file truncation, two locks are used. For serializing 71 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is, 72 * file truncate operations against block mapping, i_truncate_mutex is 73 * used. i_truncate_mutex also protects against concurrent accesses 74 * and changes to the inode private data, and in particular changes to 75 * a sequential file size on completion of direct IO writes. 76 * Serialization of mmap read IOs with truncate and syscall IO 77 * operations is done with invalidate_lock in addition to 78 * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock 79 * (invalidate_lock first, i_truncate_mutex second). 80 */ 81 struct mutex i_truncate_mutex; 82 83 /* guarded by i_truncate_mutex */ 84 unsigned int i_wr_refcnt; 85 unsigned int i_flags; 86 }; 87 88 static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode) 89 { 90 return container_of(inode, struct zonefs_inode_info, i_vnode); 91 } 92 93 /* 94 * On-disk super block (block 0). 95 */ 96 #define ZONEFS_LABEL_LEN 64 97 #define ZONEFS_UUID_SIZE 16 98 #define ZONEFS_SUPER_SIZE 4096 99 100 struct zonefs_super { 101 102 /* Magic number */ 103 __le32 s_magic; 104 105 /* Checksum */ 106 __le32 s_crc; 107 108 /* Volume label */ 109 char s_label[ZONEFS_LABEL_LEN]; 110 111 /* 128-bit uuid */ 112 __u8 s_uuid[ZONEFS_UUID_SIZE]; 113 114 /* Features */ 115 __le64 s_features; 116 117 /* UID/GID to use for files */ 118 __le32 s_uid; 119 __le32 s_gid; 120 121 /* File permissions */ 122 __le32 s_perm; 123 124 /* Padding to ZONEFS_SUPER_SIZE bytes */ 125 __u8 s_reserved[3988]; 126 127 } __packed; 128 129 /* 130 * Feature flags: specified in the s_features field of the on-disk super 131 * block struct zonefs_super and in-memory in the s_feartures field of 132 * struct zonefs_sb_info. 133 */ 134 enum zonefs_features { 135 /* 136 * Aggregate contiguous conventional zones into a single file. 137 */ 138 ZONEFS_F_AGGRCNV = 1ULL << 0, 139 /* 140 * Use super block specified UID for files instead of default 0. 141 */ 142 ZONEFS_F_UID = 1ULL << 1, 143 /* 144 * Use super block specified GID for files instead of default 0. 145 */ 146 ZONEFS_F_GID = 1ULL << 2, 147 /* 148 * Use super block specified file permissions instead of default 640. 149 */ 150 ZONEFS_F_PERM = 1ULL << 3, 151 }; 152 153 #define ZONEFS_F_DEFINED_FEATURES \ 154 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM) 155 156 /* 157 * Mount options for zone write pointer error handling. 158 */ 159 #define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */ 160 #define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */ 161 #define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */ 162 #define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */ 163 #define ZONEFS_MNTOPT_ERRORS_MASK \ 164 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \ 165 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR) 166 #define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */ 167 168 /* 169 * In-memory Super block information. 170 */ 171 struct zonefs_sb_info { 172 173 unsigned long s_mount_opts; 174 175 spinlock_t s_lock; 176 177 unsigned long long s_features; 178 kuid_t s_uid; 179 kgid_t s_gid; 180 umode_t s_perm; 181 uuid_t s_uuid; 182 unsigned int s_zone_sectors_shift; 183 184 unsigned int s_nr_files[ZONEFS_ZTYPE_MAX]; 185 186 loff_t s_blocks; 187 loff_t s_used_blocks; 188 189 unsigned int s_max_wro_seq_files; 190 atomic_t s_wro_seq_files; 191 192 unsigned int s_max_active_seq_files; 193 atomic_t s_active_seq_files; 194 195 bool s_sysfs_registered; 196 struct kobject s_kobj; 197 struct completion s_kobj_unregister; 198 }; 199 200 static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb) 201 { 202 return sb->s_fs_info; 203 } 204 205 #define zonefs_info(sb, format, args...) \ 206 pr_info("zonefs (%s): " format, sb->s_id, ## args) 207 #define zonefs_err(sb, format, args...) \ 208 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args) 209 #define zonefs_warn(sb, format, args...) \ 210 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args) 211 212 int zonefs_sysfs_register(struct super_block *sb); 213 void zonefs_sysfs_unregister(struct super_block *sb); 214 int zonefs_sysfs_init(void); 215 void zonefs_sysfs_exit(void); 216 217 #endif 218