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 (1 << 0) 43 #define ZONEFS_ZONE_ACTIVE (1 << 1) 44 45 /* 46 * In-memory inode data. 47 */ 48 struct 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 86 static 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 98 struct 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 */ 132 enum 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 */ 169 struct 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 }; 197 198 static 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) 209 210 int zonefs_sysfs_register(struct super_block *sb); 211 void zonefs_sysfs_unregister(struct super_block *sb); 212 int zonefs_sysfs_init(void); 213 void zonefs_sysfs_exit(void); 214 215 #endif 216