path: root/fs/ext2/ext2.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/include/linux/minix_fs.h
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
#include <linux/rbtree.h>
#include <linux/mm.h>
#include <linux/highmem.h>

/* XXX Here for now... not interested in restructing headers JUST now */

/* data type for block offset of block group */
typedef int ext2_grpblk_t;

/* data type for filesystem-wide blocks number */
typedef unsigned long ext2_fsblk_t;

#define E2FSBLK "%lu"

struct ext2_reserve_window {
	ext2_fsblk_t		_rsv_start;	/* First byte reserved */
	ext2_fsblk_t		_rsv_end;	/* Last byte reserved or 0 */
};

struct ext2_reserve_window_node {
	struct rb_node	 	rsv_node;
	__u32			rsv_goal_size;
	__u32			rsv_alloc_hit;
	struct ext2_reserve_window	rsv_window;
};

struct ext2_block_alloc_info {
	/* information about reservation window */
	struct ext2_reserve_window_node	rsv_window_node;
	/*
	 * was i_next_alloc_block in ext2_inode_info
	 * is the logical (file-relative) number of the
	 * most-recently-allocated block in this file.
	 * We use this for detecting linearly ascending allocation requests.
	 */
	__u32			last_alloc_logical_block;
	/*
	 * Was i_next_alloc_goal in ext2_inode_info
	 * is the *physical* companion to i_next_alloc_block.
	 * it is the physical block number of the block which was most-recently
	 * allocated to this file.  This gives us the goal (target) for the next
	 * allocation when we detect linearly ascending requests.
	 */
	ext2_fsblk_t		last_alloc_physical_block;
};

#define rsv_start rsv_window._rsv_start
#define rsv_end rsv_window._rsv_end

struct mb_cache;

/*
 * second extended-fs super-block data in memory
 */
struct ext2_sb_info {
	unsigned long s_frag_size;	/* Size of a fragment in bytes */
	unsigned long s_frags_per_block;/* Number of fragments per block */
	unsigned long s_inodes_per_block;/* Number of inodes per block */
	unsigned long s_frags_per_group;/* Number of fragments in a group */
	unsigned long s_blocks_per_group;/* Number of blocks in a group */
	unsigned long s_inodes_per_group;/* Number of inodes in a group */
	unsigned long s_itb_per_group;	/* Number of inode table blocks per group */
	unsigned long s_gdb_count;	/* Number of group descriptor blocks */
	unsigned long s_desc_per_block;	/* Number of group descriptors per block */
	unsigned long s_groups_count;	/* Number of groups in the fs */
	unsigned long s_overhead_last;  /* Last calculated overhead */
	unsigned long s_blocks_last;    /* Last seen block count */
	struct buffer_head * s_sbh;	/* Buffer containing the super block */
	struct ext2_super_block * s_es;	/* Pointer to the super block in the buffer */
	struct buffer_head ** s_group_desc;
	unsigned long  s_mount_opt;
	unsigned long s_sb_block;
	kuid_t s_resuid;
	kgid_t s_resgid;
	unsigned short s_mount_state;
	unsigned short s_pad;
	int s_addr_per_block_bits;
	int s_desc_per_block_bits;
	int s_inode_size;
	int s_first_ino;
	spinlock_t s_next_gen_lock;
	u32 s_next_generation;
	unsigned long s_dir_count;
	u8 *s_debts;
	struct percpu_counter s_freeblocks_counter;
	struct percpu_counter s_freeinodes_counter;
	struct percpu_counter s_dirs_counter;
	struct blockgroup_lock *s_blockgroup_lock;
	/* root of the per fs reservation window tree */
	spinlock_t s_rsv_window_lock;
	struct rb_root s_rsv_window_root;
	struct ext2_reserve_window_node s_rsv_window_head;
	/*
	 * s_lock protects against concurrent modifications of s_mount_state,
	 * s_blocks_last, s_overhead_last and the content of superblock's
	 * buffer pointed to by sbi->s_es.
	 *
	 * Note: It is used in ext2_show_options() to provide a consistent view
	 * of the mount options.
	 */
	spinlock_t s_lock;
	struct mb_cache *s_ea_block_cache;
	struct dax_device *s_daxdev;
};

static inline spinlock_t *
sb_bgl_lock(struct ext2_sb_info *sbi, unsigned int block_group)
{
	return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group);
}

/*
 * Define EXT2FS_DEBUG to produce debug messages
 */
#undef EXT2FS_DEBUG

/*
 * Define EXT2_RESERVATION to reserve data blocks for expanding files
 */
#define EXT2_DEFAULT_RESERVE_BLOCKS     8
/*max window size: 1024(direct blocks) + 3([t,d]indirect blocks) */
#define EXT2_MAX_RESERVE_BLOCKS         1027
#define EXT2_RESERVE_WINDOW_NOT_ALLOCATED 0
/*
 * The second extended file system version
 */
#define EXT2FS_DATE		"95/08/09"
#define EXT2FS_VERSION		"0.5b"

/*
 * Debug code
 */
#ifdef EXT2FS_DEBUG
#	define ext2_debug(f, a...)	{ \
					printk ("EXT2-fs DEBUG (%s, %d): %s:", \
						__FILE__, __LINE__, __func__); \
				  	printk (f, ## a); \
					}
#else
#	define ext2_debug(f, a...)	/**/
#endif

/*
 * Special inode numbers
 */
#define	EXT2_BAD_INO		 1	/* Bad blocks inode */
#define EXT2_ROOT_INO		 2	/* Root inode */
#define EXT2_BOOT_LOADER_INO	 5	/* Boot loader inode */
#define EXT2_UNDEL_DIR_INO	 6	/* Undelete directory inode */

/* First non-reserved inode for old ext2 filesystems */
#define EXT2_GOOD_OLD_FIRST_INO	11

static inline struct ext2_sb_info *EXT2_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

/*
 * Macro-instructions used to manage several block sizes
 */
#define EXT2_MIN_BLOCK_SIZE		1024
#define	EXT2_MAX_BLOCK_SIZE		4096
#define EXT2_MIN_BLOCK_LOG_SIZE		  10
#define EXT2_BLOCK_SIZE(s)		((s)->s_blocksize)
#define	EXT2_ADDR_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (__u32))
#define EXT2_BLOCK_SIZE_BITS(s)		((s)->s_blocksize_bits)
#define	EXT2_ADDR_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_addr_per_block_bits)
#define EXT2_INODE_SIZE(s)		(EXT2_SB(s)->s_inode_size)
#define EXT2_FIRST_INO(s)		(EXT2_SB(s)->s_first_ino)

/*
 * Macro-instructions used to manage fragments
 */
#define EXT2_MIN_FRAG_SIZE		1024
#define	EXT2_MAX_FRAG_SIZE		4096
#define EXT2_MIN_FRAG_LOG_SIZE		  10
#define EXT2_FRAG_SIZE(s)		(EXT2_SB(s)->s_frag_size)
#define EXT2_FRAGS_PER_BLOCK(s)		(EXT2_SB(s)->s_frags_per_block)

/*
 * Structure of a blocks group descriptor
 */
struct ext2_group_desc
{
	__le32	bg_block_bitmap;		/* Blocks bitmap block */
	__le32	bg_inode_bitmap;		/* Inodes bitmap block */
	__le32	bg_inode_table;		/* Inodes table block */
	__le16	bg_free_blocks_count;	/* Free blocks count */
	__le16	bg_free_inodes_count;	/* Free inodes count */
	__le16	bg_used_dirs_count;	/* Directories count */
	__le16	bg_pad;
	__le32	bg_reserved[3];
};

/*
 * Macro-instructions used to manage group descriptors
 */
#define EXT2_BLOCKS_PER_GROUP(s)	(EXT2_SB(s)->s_blocks_per_group)
#define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
#define EXT2_INODES_PER_GROUP(s)	(EXT2_SB(s)->s_inodes_per_group)
#define EXT2_DESC_PER_BLOCK_BITS(s)	(EXT2_SB(s)->s_desc_per_block_bits)

/*
 * Constants relative to the data blocks
 */
#define	EXT2_NDIR_BLOCKS		12
#define	EXT2_IND_BLOCK			EXT2_NDIR_BLOCKS
#define	EXT2_DIND_BLOCK			(EXT2_IND_BLOCK + 1)
#define	EXT2_TIND_BLOCK			(EXT2_DIND_BLOCK + 1)
#define	EXT2_N_BLOCKS			(EXT2_TIND_BLOCK + 1)

/*
 * Inode flags (GETFLAGS/SETFLAGS)
 */
#define	EXT2_SECRM_FL			FS_SECRM_FL	/* Secure deletion */
#define	EXT2_UNRM_FL			FS_UNRM_FL	/* Undelete */
#define	EXT2_COMPR_FL			FS_COMPR_FL	/* Compress file */
#define EXT2_SYNC_FL			FS_SYNC_FL	/* Synchronous updates */
#define EXT2_IMMUTABLE_FL		FS_IMMUTABLE_FL	/* Immutable file */
#define EXT2_APPEND_FL			FS_APPEND_FL	/* writes to file may only append */
#define EXT2_NODUMP_FL			FS_NODUMP_FL	/* do not dump file */
#define EXT2_NOATIME_FL			FS_NOATIME_FL	/* do not update atime */
/* Reserved for compression usage... */
#define EXT2_DIRTY_FL			FS_DIRTY_FL
#define EXT2_COMPRBLK_FL		FS_COMPRBLK_FL	/* One or more compressed clusters */
#define EXT2_NOCOMP_FL			FS_NOCOMP_FL	/* Don't compress */
#define EXT2_ECOMPR_FL			FS_ECOMPR_FL	/* Compression error */
/* End compression flags --- maybe not all used */	
#define EXT2_BTREE_FL			FS_BTREE_FL	/* btree format dir */
#define EXT2_INDEX_FL			FS_INDEX_FL	/* hash-indexed directory */
#define EXT2_IMAGIC_FL			FS_IMAGIC_FL	/* AFS directory */
#define EXT2_JOURNAL_DATA_FL		FS_JOURNAL_DATA_FL /* Reserved for ext3 */
#define EXT2_NOTAIL_FL			FS_NOTAIL_FL	/* file tail should not be merged */
#define EXT2_DIRSYNC_FL			FS_DIRSYNC_FL	/* dirsync behaviour (directories only) */
#define EXT2_TOPDIR_FL			FS_TOPDIR_FL	/* Top of directory hierarchies*/
#define EXT2_RESERVED_FL		FS_RESERVED_FL	/* reserved for ext2 lib */

#define EXT2_FL_USER_VISIBLE		FS_FL_USER_VISIBLE	/* User visible flags */
#define EXT2_FL_USER_MODIFIABLE		FS_FL_USER_MODIFIABLE	/* User modifiable flags */

/* Flags that should be inherited by new inodes from their parent. */
#define EXT2_FL_INHERITED (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\
			   EXT2_SYNC_FL | EXT2_NODUMP_FL |\
			   EXT2_NOATIME_FL | EXT2_COMPRBLK_FL |\
			   EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\
			   EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL)

/* Flags that are appropriate for regular files (all but dir-specific ones). */
#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL))

/* Flags that are appropriate for non-directories/regular files. */
#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL)

/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags)
{
	if (S_ISDIR(mode))
		return flags;
	else if (S_ISREG(mode))
		return flags & EXT2_REG_FLMASK;
	else
		return flags & EXT2_OTHER_FLMASK;
}

/*
 * ioctl commands
 */
#define	EXT2_IOC_GETFLAGS		FS_IOC_GETFLAGS
#define	EXT2_IOC_SETFLAGS		FS_IOC_SETFLAGS
#define	EXT2_IOC_GETVERSION		FS_IOC_GETVERSION
#define	EXT2_IOC_SETVERSION		FS_IOC_SETVERSION
#define	EXT2_IOC_GETRSVSZ		_IOR('f', 5, long)
#define	EXT2_IOC_SETRSVSZ		_IOW('f', 6, long)

/*
 * ioctl commands in 32 bit emulation
 */
#define EXT2_IOC32_GETFLAGS		FS_IOC32_GETFLAGS
#define EXT2_IOC32_SETFLAGS		FS_IOC32_SET