/* SPDX-License-Identifier: GPL-2.0 */
/*
* Simple zone file system for zoned block devices.
*
* Copyright (C) 2019 Western Digital Corporation or its affiliates.
*/
#ifndef __ZONEFS_H__
#define __ZONEFS_H__
#include <linux/fs.h>
#include <linux/magic.h>
#include <linux/uuid.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/kobject.h>
/*
* Maximum length of file names: this only needs to be large enough to fit
* the zone group directory names and a decimal zone number for file names.
* 16 characters is plenty.
*/
#define ZONEFS_NAME_MAX 16
/*
* Zone types: ZONEFS_ZTYPE_SEQ is used for all sequential zone types
* defined in linux/blkzoned.h, that is, BLK_ZONE_TYPE_SEQWRITE_REQ and
* BLK_ZONE_TYPE_SEQWRITE_PREF.
*/
enum zonefs_ztype {
ZONEFS_ZTYPE_CNV,
ZONEFS_ZTYPE_SEQ,
ZONEFS_ZTYPE_MAX,
};
static inline enum zonefs_ztype zonefs_zone_type(struct blk_zone *zone)
{
if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
return ZONEFS_ZTYPE_CNV;
return ZONEFS_ZTYPE_SEQ;
}
#define ZONEFS_ZONE_INIT_MODE (1U << 0)
#define ZONEFS_ZONE_OPEN (1U << 1)
#define ZONEFS_ZONE_ACTIVE (1U << 2)
#define ZONEFS_ZONE_OFFLINE (1U << 3)
#define ZONEFS_ZONE_READONLY (1U << 4)
#define ZONEFS_ZONE_CNV (1U << 31)
/*
* In-memory per-file inode zone data.
*/
struct zonefs_zone {
/* Zone state flags */
unsigned int z_flags;
/* Zone start sector (512B unit) */
sector_t z_sector;
/* Zone size (bytes) */
loff_t z_size;
/* Zone capacity (file maximum size, bytes) */
loff_t z_capacity;
/* Write pointer offset in the zone (sequential zones only, bytes) */
loff_t z_wpoffset;
/* Saved inode uid, gid and access rights */
umode_t z_mode;
kuid_t z_uid;
kgid_t z_gid;
};
/*
* In memory zone group information: all zones of a group are exposed
* as files, one file per zone.
*/
struct zonefs_zone_group {
struct inode *g_inode;
unsigned int g_nr_zones;
struct zonefs_zone *g_zones;
};
/*
* In-memory inode data.
*/
struct zonefs_inode_info {
struct inode i_vnode;
/*
* To serialise fully against both syscall and mmap based IO and
* sequential file truncation, two locks are used. For serializing
* zonefs_seq_file_truncate() against zonefs_iomap_begin(), that is,
* file truncate operations against block mapping, i_truncate_mutex is
* used. i_truncate_mutex also protects against concurrent accesses
* and changes to the inode private data, and in particular changes to
* a sequential file size on completion of direct IO writes.
* Serialization of mmap read IOs with truncate and syscall IO
* operations is done with invalidate_lock in addition to
* i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock
* (invalidate_lock first, i_truncate_mutex second).
*/
struct mutex i_truncate_mutex;
/* guarded by i_truncate_mutex */
unsigned int i_wr_refcnt;
};
static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
{
return container_of(inode, struct zonefs_inode_info, i_vnode);
}
static inline bool zonefs_zone_is_cnv(struct zonefs_zone *z)
{
return z->z_flags & ZONEFS_ZONE_CNV;
}
static inline bool zonefs_zone_is_seq(struct zonefs_zone *z)
{
return !zonefs_zone_is_cnv(z);
}
static inline struct zonefs_zone *zonefs_inode_zone(struct inode *inode)
{
return inode->i_private;
}
static inline bool zonefs_inode_is_cnv(struct inode *inode)
{
return zonefs_zone_is_cnv(zonefs_inode_zone(inode));
}
static inline bool zonefs_inode_is_seq(struct inode *inode)
{
return zonefs_zone_is_seq(zonefs_inode_zone(inode));
}
/*
* On-disk super block (block 0).
*/
#define ZONEFS_LABEL_LEN 64
#define ZONEFS_UUID_SIZE 16
#define ZONEFS_SUPER_SIZE 4096
struct zonefs_super {
/* Magic number */
__le32 s_magic;
/* Checksum */
__le32 s_crc;
/* Volume label */
char s_label[ZONEFS_LABEL_LEN];
/* 128-bit uuid */
__u8 s_uuid[ZONEFS_UUID_SIZE];
/* Features */
__le64 s_features;
/* UID/GID to use for files */
__le32 s_uid;
__le32 s_gid;
/* File permissions */
__le32 s_perm;
/* Padding to ZONEFS_SUPER_SIZE bytes */
__u8 s_reserved[3988];
} __packed;
/*
* Feature flags: specified in the s_features field of the on-disk super
* block struct zonefs_super and in-memory in the s_feartures field of
* struct zonefs_sb_info.
*/
enum zonefs_features {
/*
* Aggregate contiguous conventional zones into a single file.
*/
ZONEFS_F_AGGRCNV = 1ULL << 0,
/*
* Use super block specified UID for files instead of default 0.
*/
ZONEFS_F_UID = 1ULL << 1,
/*
* Use super block specified GID for files instead of default 0.
*/
ZONEFS_F_GID = 1ULL << 2,
/*
* Use super block specified file permissions instead of default 640.
*/
ZONEFS_F_PERM = 1ULL << 3,
};
#define ZONEFS_F_DEFINED_FEATURES \
(ZONEFS_F_AGGRCNV | ZONEFS_F_UID | ZONEFS_F_GID | ZONEFS_F_PERM)
/*
* Mount options for zone write pointer error handling.
*/
#define ZONEFS_MNTOPT_ERRORS_RO (1 << 0) /* Make zone file readonly */
#define ZONEFS_MNTOPT_ERRORS_ZRO (1 << 1) /* Make zone file offline */
#define ZONEFS_MNTOPT_ERRORS_ZOL (1 << 2) /* Make zone file offline */
#define ZONEFS_MNTOPT_ERRORS_REPAIR (1 << 3) /* Remount read-only */
#define ZONEFS_MNTOPT_ERRORS_MASK \
(ZONEFS_MNTOPT_ERRORS_RO | ZONEFS_MNTOPT_ERRORS_ZRO | \
ZONEFS_MNTOPT_ERRORS_ZOL | ZONEFS_MNTOPT_ERRORS_REPAIR)
#define ZONEFS_MNTOPT_EXPLICIT_OPEN (1 << 4) /* Explicit open/close of zones on open/close */
/*
* In-memory Super block information.
*/
struct zonefs_sb_info {
unsigned long s_mount_opts;
spinlock_t s_lock;
unsigned long long s_features;
kuid_t s_uid;
kgid_t s_gid;
umode_t s_perm;
uuid_t s_uuid;
unsigned int s_zone_sectors_shift;
struct zonefs_zone_group s_zgroup[ZONEFS_ZTYPE_MAX];
loff_t s_blocks;
loff_t s_used_blocks;
unsigned int s_max_wro_seq_files;
atomic_t s_wro_seq_files;
unsigned int s_max_active_seq_files;
atomic_t s_active_seq_files;
bool s_sysfs_registered;
struct kobject s_kobj;
struct completion s_kobj_unregister;
};
static inline struct zonefs_sb_info *ZONEFS_SB(struct super_block *sb)
{
return sb->s_fs_info;
}
#define zonefs_info(sb, format, args...) \
pr_info("zonefs (%s): " format, sb->s_id, ## args)
#define zonefs_err(sb, format, args...) \
pr_err("zonefs (%s) ERROR: " format, sb->s_id, ## args)
#define zonefs_warn(sb, format, args...) \
pr_warn("zonefs (%s) WARNING: " format, sb->s_id, ## args)
/* In super.c */
void zonefs_inode_account_active(struct inode *inode);
int zonefs_inode_zone_mgmt(struct inode *inode, enum req_op op);
void zonefs_i_size_write(struct inode *inode, loff_t isize);
void zonefs_update_stats(struct inode *inode, loff_t new_isize);
void __zonefs_io_error(struct inode *inode, bool write);
static inline void zonefs_io_error(struct inode *inode, bool write)
{
struct zonefs_inode_info *zi = ZONEFS_I(inode);
mutex_lock(&zi->i_truncate_mutex);
__zonefs_io_error(inode, write);
mutex_unlock(&zi->i_truncate_mutex);
}
/* In super.c */
extern const struct inode_operations zonefs_dir_inode_operations;
extern const struct file_operations zonefs_dir_operations;
/* In file.c */
extern const struct address_space_operations zonefs_file_aops;
extern const struct file_operations zonefs_file_operations;
int zonefs_file_truncate(struct inode *inode, loff_t isize);
/* In sysfs.c */
int zonefs_sysfs_register(struct super_block *sb);
void zonefs_sysfs_unregister(struct super_block *sb);
int zonefs_sysfs_init(void);
void zonefs_sysfs_exit(void);
#endif
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