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>
15 #include <linux/kobject.h>
18 * Maximum length of file names: this only needs to be large enough to fit
19 * the zone group directory names and a decimal zone number for file names.
20 * 16 characters is plenty.
22 #define ZONEFS_NAME_MAX 16
25 * Zone types: ZONEFS_ZTYPE_SEQ is used for all sequential zone types
26 * defined in linux/blkzoned.h, that is, BLK_ZONE_TYPE_SEQWRITE_REQ and
27 * BLK_ZONE_TYPE_SEQWRITE_PREF.
35 static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
37 if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
38 return ZONEFS_ZTYPE_CNV;
39 return ZONEFS_ZTYPE_SEQ;
42 #define ZONEFS_ZONE_INIT_MODE (1U << 0)
43 #define ZONEFS_ZONE_OPEN (1U << 1)
44 #define ZONEFS_ZONE_ACTIVE (1U << 2)
45 #define ZONEFS_ZONE_OFFLINE (1U << 3)
46 #define ZONEFS_ZONE_READONLY (1U << 4)
47 #define ZONEFS_ZONE_CNV (1U << 31)
50 * In-memory per-file inode zone data.
53 /* Zone state flags */
56 /* Zone start sector (512B unit) */
59 /* Zone size (bytes) */
62 /* Zone capacity (file maximum size, bytes) */
65 /* Write pointer offset in the zone (sequential zones only, bytes) */
70 * In memory zone group information: all zones of a group are exposed
71 * as files, one file per zone.
73 struct zonefs_zone_group {
74 unsigned int g_nr_zones;
75 struct zonefs_zone *g_zones;
79 * In-memory inode data.
81 struct zonefs_inode_info {
85 * To serialise fully against both syscall and mmap based IO and
86 * sequential file truncation, two locks are used. For serializing
87 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
88 * file truncate operations against block mapping, i_truncate_mutex is
89 * used. i_truncate_mutex also protects against concurrent accesses
90 * and changes to the inode private data, and in particular changes to
91 * a sequential file size on completion of direct IO writes.
92 * Serialization of mmap read IOs with truncate and syscall IO
93 * operations is done with invalidate_lock in addition to
94 * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock
95 * (invalidate_lock first, i_truncate_mutex second).
97 struct mutex i_truncate_mutex;
99 /* guarded by i_truncate_mutex */
100 unsigned int i_wr_refcnt;
103 static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
105 return container_of(inode, struct zonefs_inode_info, i_vnode);
108 static inline bool zonefs_zone_is_cnv(struct zonefs_zone *z)
110 return z->z_flags & ZONEFS_ZONE_CNV;
113 static inline bool zonefs_zone_is_seq(struct zonefs_zone *z)
115 return !zonefs_zone_is_cnv(z);
118 static inline struct zonefs_zone *zonefs_inode_zone(struct inode *inode)
120 return inode->i_private;
123 static inline bool zonefs_inode_is_cnv(struct inode *inode)
125 return zonefs_zone_is_cnv(zonefs_inode_zone(inode));
128 static inline bool zonefs_inode_is_seq(struct inode *inode)
130 return zonefs_zone_is_seq(zonefs_inode_zone(inode));
134 * On-disk super block (block 0).
136 #define ZONEFS_LABEL_LEN 64
137 #define ZONEFS_UUID_SIZE 16
138 #define ZONEFS_SUPER_SIZE 4096
140 struct zonefs_super {
149 char s_label[ZONEFS_LABEL_LEN];
152 __u8 s_uuid[ZONEFS_UUID_SIZE];
157 /* UID/GID to use for files */
161 /* File permissions */
164 /* Padding to ZONEFS_SUPER_SIZE bytes */
165 __u8 s_reserved[3988];
170 * Feature flags: specified in the s_features field of the on-disk super
171 * block struct zonefs_super and in-memory in the s_feartures field of
172 * struct zonefs_sb_info.
174 enum zonefs_features {
176 * Aggregate contiguous conventional zones into a single file.
178 ZONEFS_F_AGGRCNV = 1ULL << 0,
180 * Use super block specified UID for files instead of default 0.
182 ZONEFS_F_UID = 1ULL << 1,
184 * Use super block specified GID for files instead of default 0.
186 ZONEFS_F_GID = 1ULL << 2,
188 * Use super block specified file permissions instead of default 640.
190 ZONEFS_F_PERM = 1ULL << 3,
193 #define ZONEFS_F_DEFINED_FEATURES \
194 (ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
197 * Mount options for zone write pointer error handling.
199 #define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */
200 #define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */
201 #define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */
202 #define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */
203 #define ZONEFS_MNTOPT_ERRORS_MASK \
204 (ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
205 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
206 #define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */
209 * In-memory Super block information.
211 struct zonefs_sb_info {
213 unsigned long s_mount_opts;
217 unsigned long long s_features;
222 unsigned int s_zone_sectors_shift;
224 struct zonefs_zone_group s_zgroup[ZONEFS_ZTYPE_MAX];
227 loff_t s_used_blocks;
229 unsigned int s_max_wro_seq_files;
230 atomic_t s_wro_seq_files;
232 unsigned int s_max_active_seq_files;
233 atomic_t s_active_seq_files;
235 bool s_sysfs_registered;
236 struct kobject s_kobj;
237 struct completion s_kobj_unregister;
240 static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
242 return sb->s_fs_info;
245 #define zonefs_info(sb, format, args...) \
246 pr_info("zonefs (%s): " format, sb->s_id, ## args)
247 #define zonefs_err(sb, format, args...) \
248 pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
249 #define zonefs_warn(sb, format, args...) \
250 pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
253 void zonefs_inode_account_active(struct inode *inode);
254 int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op);
255 void zonefs_i_size_write(struct inode *inode, loff_t isize);
256 void zonefs_update_stats(struct inode *inode, loff_t new_isize);
257 void __zonefs_io_error(struct inode *inode, bool write);
259 static inline void zonefs_io_error(struct inode *inode, bool write)
261 struct zonefs_inode_info *zi = ZONEFS_I(inode);
263 mutex_lock(&zi->i_truncate_mutex);
264 __zonefs_io_error(inode, write);
265 mutex_unlock(&zi->i_truncate_mutex);
269 extern const struct address_space_operations zonefs_file_aops;
270 extern const struct file_operations zonefs_file_operations;
271 int zonefs_file_truncate(struct inode *inode, loff_t isize);
274 int zonefs_sysfs_register(struct super_block *sb);
275 void zonefs_sysfs_unregister(struct super_block *sb);
276 int zonefs_sysfs_init(void);
277 void zonefs_sysfs_exit(void);