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 */ 28enum zonefs_ztype { 29 ZONEFS_ZTYPE_CNV, 30 ZONEFS_ZTYPE_SEQ, 31 ZONEFS_ZTYPE_MAX, 32}; 33 34static 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 */ 46struct 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 i_mmap_sem in addition to i_truncate_mutex. 74 * Only zonefs_seq_file_truncate() takes both lock (i_mmap_sem first, 75 * i_truncate_mutex second). 76 */ 77 struct mutex i_truncate_mutex; 78 struct rw_semaphore i_mmap_sem; 79 80 /* guarded by i_truncate_mutex */ 81 unsigned int i_wr_refcnt; 82 unsigned int i_flags; 83}; 84 85static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode) 86{ 87 return container_of(inode, struct zonefs_inode_info, i_vnode); 88} 89 90/* 91 * On-disk super block (block 0). 92 */ 93#define ZONEFS_LABEL_LEN 64 94#define ZONEFS_UUID_SIZE 16 95#define ZONEFS_SUPER_SIZE 4096 96 97struct zonefs_super { 98 99 /* Magic number */ 100 __le32 s_magic; 101 102 /* Checksum */ 103 __le32 s_crc; 104 105 /* Volume label */ 106 char s_label[ZONEFS_LABEL_LEN]; 107 108 /* 128-bit uuid */ 109 __u8 s_uuid[ZONEFS_UUID_SIZE]; 110 111 /* Features */ 112 __le64 s_features; 113 114 /* UID/GID to use for files */ 115 __le32 s_uid; 116 __le32 s_gid; 117 118 /* File permissions */ 119 __le32 s_perm; 120 121 /* Padding to ZONEFS_SUPER_SIZE bytes */ 122 __u8 s_reserved[3988]; 123 124} __packed; 125 126/* 127 * Feature flags: specified in the s_features field of the on-disk super 128 * block struct zonefs_super and in-memory in the s_feartures field of 129 * struct zonefs_sb_info. 130 */ 131enum zonefs_features { 132 /* 133 * Aggregate contiguous conventional zones into a single file. 134 */ 135 ZONEFS_F_AGGRCNV = 1ULL << 0, 136 /* 137 * Use super block specified UID for files instead of default 0. 138 */ 139 ZONEFS_F_UID = 1ULL << 1, 140 /* 141 * Use super block specified GID for files instead of default 0. 142 */ 143 ZONEFS_F_GID = 1ULL << 2, 144 /* 145 * Use super block specified file permissions instead of default 640. 146 */ 147 ZONEFS_F_PERM = 1ULL << 3, 148}; 149 150#define ZONEFS_F_DEFINED_FEATURES \ 151 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM) 152 153/* 154 * Mount options for zone write pointer error handling. 155 */ 156#define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */ 157#define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */ 158#define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */ 159#define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */ 160#define ZONEFS_MNTOPT_ERRORS_MASK \ 161 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \ 162 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR) 163#define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */ 164 165/* 166 * In-memory Super block information. 167 */ 168struct zonefs_sb_info { 169 170 unsigned long s_mount_opts; 171 172 spinlock_t s_lock; 173 174 unsigned long long s_features; 175 kuid_t s_uid; 176 kgid_t s_gid; 177 umode_t s_perm; 178 uuid_t s_uuid; 179 unsigned int s_zone_sectors_shift; 180 181 unsigned int s_nr_files[ZONEFS_ZTYPE_MAX]; 182 183 loff_t s_blocks; 184 loff_t s_used_blocks; 185 186 unsigned int s_max_open_zones; 187 atomic_t s_open_zones; 188}; 189 190static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb) 191{ 192 return sb->s_fs_info; 193} 194 195#define zonefs_info(sb, format, args...) \ 196 pr_info("zonefs (%s): " format, sb->s_id, ## args) 197#define zonefs_err(sb, format, args...) \ 198 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args) 199#define zonefs_warn(sb, format, args...) \ 200 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args) 201 202#endif 203