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 190