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 #define ZONEFS_ZONE_OPEN (1 << 0) 42 43 /* 44 * In-memory inode data. 45 */ 46 struct zonefs_inode_info { 47 struct inode i_vnode; 48 49 /* File zone type */ 50 enum zonefs_ztype i_ztype; 51 52 /* File zone start sector (512B unit) */ 53 sector_t i_zsector; 54 55 /* File zone write pointer position (sequential zones only) */ 56 loff_t i_wpoffset; 57 58 /* File maximum size */ 59 loff_t i_max_size; 60 61 /* File zone size */ 62 loff_t i_zone_size; 63 64 /* 65 * To serialise fully against both syscall and mmap based IO and 66 * sequential file truncation, two locks are used. For serializing 67 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is, 68 * file truncate operations against block mapping, i_truncate_mutex is 69 * used. i_truncate_mutex also protects against concurrent accesses 70 * and changes to the inode private data, and in particular changes to 71 * a sequential file size on completion of direct IO writes. 72 * Serialization of mmap read IOs with truncate and syscall IO 73 * operations is done with invalidate_lock in addition to 74 * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock 75 * (invalidate_lock first, i_truncate_mutex second). 76 */ 77 struct mutex i_truncate_mutex; 78 79 /* guarded by i_truncate_mutex */ 80 unsigned int i_wr_refcnt; 81 unsigned int i_flags; 82 }; 83 84 static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode) 85 { 86 return container_of(inode, struct zonefs_inode_info, i_vnode); 87 } 88 89 /* 90 * On-disk super block (block 0). 91 */ 92 #define ZONEFS_LABEL_LEN 64 93 #define ZONEFS_UUID_SIZE 16 94 #define ZONEFS_SUPER_SIZE 4096 95 96 struct zonefs_super { 97 98 /* Magic number */ 99 __le32 s_magic; 100 101 /* Checksum */ 102 __le32 s_crc; 103 104 /* Volume label */ 105 char s_label[ZONEFS_LABEL_LEN]; 106 107 /* 128-bit uuid */ 108 __u8 s_uuid[ZONEFS_UUID_SIZE]; 109 110 /* Features */ 111 __le64 s_features; 112 113 /* UID/GID to use for files */ 114 __le32 s_uid; 115 __le32 s_gid; 116 117 /* File permissions */ 118 __le32 s_perm; 119 120 /* Padding to ZONEFS_SUPER_SIZE bytes */ 121 __u8 s_reserved[3988]; 122 123 } __packed; 124 125 /* 126 * Feature flags: specified in the s_features field of the on-disk super 127 * block struct zonefs_super and in-memory in the s_feartures field of 128 * struct zonefs_sb_info. 129 */ 130 enum zonefs_features { 131 /* 132 * Aggregate contiguous conventional zones into a single file. 133 */ 134 ZONEFS_F_AGGRCNV = 1ULL << 0, 135 /* 136 * Use super block specified UID for files instead of default 0. 137 */ 138 ZONEFS_F_UID = 1ULL << 1, 139 /* 140 * Use super block specified GID for files instead of default 0. 141 */ 142 ZONEFS_F_GID = 1ULL << 2, 143 /* 144 * Use super block specified file permissions instead of default 640. 145 */ 146 ZONEFS_F_PERM = 1ULL << 3, 147 }; 148 149 #define ZONEFS_F_DEFINED_FEATURES \ 150 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM) 151 152 /* 153 * Mount options for zone write pointer error handling. 154 */ 155 #define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */ 156 #define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */ 157 #define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */ 158 #define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */ 159 #define ZONEFS_MNTOPT_ERRORS_MASK \ 160 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \ 161 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR) 162 #define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */ 163 164 /* 165 * In-memory Super block information. 166 */ 167 struct zonefs_sb_info { 168 169 unsigned long s_mount_opts; 170 171 spinlock_t s_lock; 172 173 unsigned long long s_features; 174 kuid_t s_uid; 175 kgid_t s_gid; 176 umode_t s_perm; 177 uuid_t s_uuid; 178 unsigned int s_zone_sectors_shift; 179 180 unsigned int s_nr_files[ZONEFS_ZTYPE_MAX]; 181 182 loff_t s_blocks; 183 loff_t s_used_blocks; 184 185 unsigned int s_max_open_zones; 186 atomic_t s_open_zones; 187 }; 188 189 static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb) 190 { 191 return sb->s_fs_info; 192 } 193 194 #define zonefs_info(sb, format, args...) \ 195 pr_info("zonefs (%s): " format, sb->s_id, ## args) 196 #define zonefs_err(sb, format, args...) \ 197 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args) 198 #define zonefs_warn(sb, format, args...) \ 199 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args) 200 201 #endif 202