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