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#include <linux/kobject.h>
16
17/*
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.
21 */
22#define ZONEFS_NAME_MAX		16
23
24/*
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.
28 */
29enum zonefs_ztype {
30	ZONEFS_ZTYPE_CNV,
31	ZONEFS_ZTYPE_SEQ,
32	ZONEFS_ZTYPE_MAX,
33};
34
35static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
36{
37	if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
38		return ZONEFS_ZTYPE_CNV;
39	return ZONEFS_ZTYPE_SEQ;
40}
41
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)
48
49/*
50 * In-memory per-file inode zone data.
51 */
52struct zonefs_zone {
53	/* Zone state flags */
54	unsigned int		z_flags;
55
56	/* Zone start sector (512B unit) */
57	sector_t		z_sector;
58
59	/* Zone size (bytes) */
60	loff_t			z_size;
61
62	/* Zone capacity (file maximum size, bytes) */
63	loff_t			z_capacity;
64
65	/* Write pointer offset in the zone (sequential zones only, bytes) */
66	loff_t			z_wpoffset;
67
68	/* Saved inode uid, gid and access rights */
69	umode_t			z_mode;
70	kuid_t			z_uid;
71	kgid_t			z_gid;
72};
73
74/*
75 * In memory zone group information: all zones of a group are exposed
76 * as files, one file per zone.
77 */
78struct zonefs_zone_group {
79	struct inode		*g_inode;
80	unsigned int		g_nr_zones;
81	struct zonefs_zone	*g_zones;
82};
83
84/*
85 * In-memory inode data.
86 */
87struct zonefs_inode_info {
88	struct inode		i_vnode;
89
90	/*
91	 * To serialise fully against both syscall and mmap based IO and
92	 * sequential file truncation, two locks are used. For serializing
93	 * zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
94	 * file truncate operations against block mapping, i_truncate_mutex is
95	 * used. i_truncate_mutex also protects against concurrent accesses
96	 * and changes to the inode private data, and in particular changes to
97	 * a sequential file size on completion of direct IO writes.
98	 * Serialization of mmap read IOs with truncate and syscall IO
99	 * operations is done with invalidate_lock in addition to
100	 * i_truncate_mutex.  Only zonefs_seq_file_truncate() takes both lock
101	 * (invalidate_lock first, i_truncate_mutex second).
102	 */
103	struct mutex		i_truncate_mutex;
104
105	/* guarded by i_truncate_mutex */
106	unsigned int		i_wr_refcnt;
107};
108
109static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
110{
111	return container_of(inode, struct zonefs_inode_info, i_vnode);
112}
113
114static inline bool zonefs_zone_is_cnv(struct zonefs_zone *z)
115{
116	return z->z_flags & ZONEFS_ZONE_CNV;
117}
118
119static inline bool zonefs_zone_is_seq(struct zonefs_zone *z)
120{
121	return !zonefs_zone_is_cnv(z);
122}
123
124static inline struct zonefs_zone *zonefs_inode_zone(struct inode *inode)
125{
126	return inode->i_private;
127}
128
129static inline bool zonefs_inode_is_cnv(struct inode *inode)
130{
131	return zonefs_zone_is_cnv(zonefs_inode_zone(inode));
132}
133
134static inline bool zonefs_inode_is_seq(struct inode *inode)
135{
136	return zonefs_zone_is_seq(zonefs_inode_zone(inode));
137}
138
139/*
140 * On-disk super block (block 0).
141 */
142#define ZONEFS_LABEL_LEN	64
143#define ZONEFS_UUID_SIZE	16
144#define ZONEFS_SUPER_SIZE	4096
145
146struct zonefs_super {
147
148	/* Magic number */
149	__le32		s_magic;
150
151	/* Checksum */
152	__le32		s_crc;
153
154	/* Volume label */
155	char		s_label[ZONEFS_LABEL_LEN];
156
157	/* 128-bit uuid */
158	__u8		s_uuid[ZONEFS_UUID_SIZE];
159
160	/* Features */
161	__le64		s_features;
162
163	/* UID/GID to use for files */
164	__le32		s_uid;
165	__le32		s_gid;
166
167	/* File permissions */
168	__le32		s_perm;
169
170	/* Padding to ZONEFS_SUPER_SIZE bytes */
171	__u8		s_reserved[3988];
172
173} __packed;
174
175/*
176 * Feature flags: specified in the s_features field of the on-disk super
177 * block struct zonefs_super and in-memory in the s_feartures field of
178 * struct zonefs_sb_info.
179 */
180enum zonefs_features {
181	/*
182	 * Aggregate contiguous conventional zones into a single file.
183	 */
184	ZONEFS_F_AGGRCNV = 1ULL << 0,
185	/*
186	 * Use super block specified UID for files instead of default 0.
187	 */
188	ZONEFS_F_UID = 1ULL << 1,
189	/*
190	 * Use super block specified GID for files instead of default 0.
191	 */
192	ZONEFS_F_GID = 1ULL << 2,
193	/*
194	 * Use super block specified file permissions instead of default 640.
195	 */
196	ZONEFS_F_PERM = 1ULL << 3,
197};
198
199#define ZONEFS_F_DEFINED_FEATURES \
200	(ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
201
202/*
203 * Mount options for zone write pointer error handling.
204 */
205#define ZONEFS_MNTOPT_ERRORS_RO		(1 << 0) /* Make zone file readonly */
206#define ZONEFS_MNTOPT_ERRORS_ZRO	(1 << 1) /* Make zone file offline */
207#define ZONEFS_MNTOPT_ERRORS_ZOL	(1 << 2) /* Make zone file offline */
208#define ZONEFS_MNTOPT_ERRORS_REPAIR	(1 << 3) /* Remount read-only */
209#define ZONEFS_MNTOPT_ERRORS_MASK	\
210	(ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
211	 ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
212#define ZONEFS_MNTOPT_EXPLICIT_OPEN	(1 << 4) /* Explicit open/close of zones on open/close */
213
214/*
215 * In-memory Super block information.
216 */
217struct zonefs_sb_info {
218
219	unsigned long		s_mount_opts;
220
221	spinlock_t		s_lock;
222
223	unsigned long long	s_features;
224	kuid_t			s_uid;
225	kgid_t			s_gid;
226	umode_t			s_perm;
227	uuid_t			s_uuid;
228	unsigned int		s_zone_sectors_shift;
229
230	struct zonefs_zone_group s_zgroup[ZONEFS_ZTYPE_MAX];
231
232	loff_t			s_blocks;
233	loff_t			s_used_blocks;
234
235	unsigned int		s_max_wro_seq_files;
236	atomic_t		s_wro_seq_files;
237
238	unsigned int		s_max_active_seq_files;
239	atomic_t		s_active_seq_files;
240
241	bool			s_sysfs_registered;
242	struct kobject		s_kobj;
243	struct completion	s_kobj_unregister;
244};
245
246static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
247{
248	return sb->s_fs_info;
249}
250
251#define zonefs_info(sb, format, args...)	\
252	pr_info("zonefs (%s): " format, sb->s_id, ## args)
253#define zonefs_err(sb, format, args...)		\
254	pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
255#define zonefs_warn(sb, format, args...)	\
256	pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
257
258/* In super.c */
259void zonefs_inode_account_active(struct inode *inode);
260int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op);
261void zonefs_i_size_write(struct inode *inode, loff_t isize);
262void zonefs_update_stats(struct inode *inode, loff_t new_isize);
263void __zonefs_io_error(struct inode *inode, bool write);
264
265static inline void zonefs_io_error(struct inode *inode, bool write)
266{
267	struct zonefs_inode_info *zi = ZONEFS_I(inode);
268
269	mutex_lock(&zi->i_truncate_mutex);
270	__zonefs_io_error(inode, write);
271	mutex_unlock(&zi->i_truncate_mutex);
272}
273
274/* In super.c */
275extern const struct inode_operations zonefs_dir_inode_operations;
276extern const struct file_operations zonefs_dir_operations;
277
278/* In file.c */
279extern const struct address_space_operations zonefs_file_aops;
280extern const struct file_operations zonefs_file_operations;
281int zonefs_file_truncate(struct inode *inode, loff_t isize);
282
283/* In sysfs.c */
284int zonefs_sysfs_register(struct super_block *sb);
285void zonefs_sysfs_unregister(struct super_block *sb);
286int zonefs_sysfs_init(void);
287void zonefs_sysfs_exit(void);
288
289#endif
290