1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Simple zone file system for zoned block devices.
5 * Copyright (C) 2019 Western Digital Corporation or its affiliates.
11 #include <linux/magic.h>
12 #include <linux/uuid.h>
13 #include <linux/mutex.h>
14 #include <linux/rwsem.h>
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.
21 #define ZONEFS_NAME_MAX 16
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.
34 static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
36 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
37 return ZONEFS_ZTYPE_CNV;
38 return ZONEFS_ZTYPE_SEQ;
42 * In-memory inode data.
44 struct zonefs_inode_info {
48 enum zonefs_ztype i_ztype;
50 /* File zone start sector (512B unit) */
53 /* File zone write pointer position (sequential zones only) */
56 /* File maximum size */
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).
75 struct mutex i_truncate_mutex;
76 struct rw_semaphore i_mmap_sem;
79 static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
81 return container_of(inode, struct zonefs_inode_info, i_vnode);
85 * On-disk super block (block 0).
87 #define ZONEFS_LABEL_LEN 64
88 #define ZONEFS_UUID_SIZE 16
89 #define ZONEFS_SUPER_SIZE 4096
100 char s_label[ZONEFS_LABEL_LEN];
103 __u8 s_uuid[ZONEFS_UUID_SIZE];
108 /* UID/GID to use for files */
112 /* File permissions */
115 /* Padding to ZONEFS_SUPER_SIZE bytes */
116 __u8 s_reserved[3988];
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.
125 enum zonefs_features {
127 * Aggregate contiguous conventional zones into a single file.
129 ZONEFS_F_AGGRCNV = 1ULL << 0,
131 * Use super block specified UID for files instead of default 0.
133 ZONEFS_F_UID = 1ULL << 1,
135 * Use super block specified GID for files instead of default 0.
137 ZONEFS_F_GID = 1ULL << 2,
139 * Use super block specified file permissions instead of default 640.
141 ZONEFS_F_PERM = 1ULL << 3,
144 #define ZONEFS_F_DEFINED_FEATURES \
145 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
148 * Mount options for zone write pointer error handling.
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)
159 * In-memory Super block information.
161 struct zonefs_sb_info {
163 unsigned long s_mount_opts;
167 unsigned long long s_features;
172 unsigned int s_zone_sectors_shift;
174 unsigned int s_nr_files[ZONEFS_ZTYPE_MAX];
177 loff_t s_used_blocks;
180 static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
182 return sb->s_fs_info;
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)