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-rw-r--r--fs/zonefs/zonefs.h189
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diff --git a/fs/zonefs/zonefs.h b/fs/zonefs/zonefs.h
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+/* 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>
+
+/*
+ * 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;
+}
+
+/*
+ * In-memory inode data.
+ */
+struct zonefs_inode_info {
+ struct inode i_vnode;
+
+ /* File zone type */
+ enum zonefs_ztype i_ztype;
+
+ /* File zone start sector (512B unit) */
+ sector_t i_zsector;
+
+ /* File zone write pointer position (sequential zones only) */
+ loff_t i_wpoffset;
+
+ /* File maximum size */
+ loff_t i_max_size;
+
+ /*
+ * 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 i_mmap_sem in addition to i_truncate_mutex.
+ * Only zonefs_seq_file_truncate() takes both lock (i_mmap_sem first,
+ * i_truncate_mutex second).
+ */
+ struct mutex i_truncate_mutex;
+ struct rw_semaphore i_mmap_sem;
+};
+
+static inline struct zonefs_inode_info *ZONEFS_I(struct inode *inode)
+{
+ return container_of(inode, struct zonefs_inode_info, i_vnode);
+}
+
+/*
+ * 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)
+
+/*
+ * 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;
+
+ unsigned int s_nr_files[ZONEFS_ZTYPE_MAX];
+
+ loff_t s_blocks;
+ loff_t s_used_blocks;
+};
+
+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)
+
+#endif