fs/ext4/mballoc.h - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  fs/ext4/mballoc.h
  *
  *  Written by: Alex Tomas <alex@clusterfs.com>
  *
  */
 #ifndef _EXT4_MBALLOC_H
 #define _EXT4_MBALLOC_H

 #include <linux/time.h>
 #include <linux/fs.h>
 #include <linux/namei.h>
 #include <linux/quotaops.h>
 #include <linux/buffer_head.h>
 #include <linux/module.h>
 #include <linux/swap.h>
 #include <linux/proc_fs.h>
 #include <linux/pagemap.h>
 #include <linux/seq_file.h>
 #include <linux/blkdev.h>
 #include <linux/mutex.h>
 #include "ext4_jbd2.h"
 #include "ext4.h"

 /*
  * mb_debug() dynamic printk msgs could be used to debug mballoc code.
  */
 #ifdef CONFIG_EXT4_DEBUG
 #define mb_debug(sb, fmt, ...)						\
 	pr_debug("[%s/%d] EXT4-fs (%s): (%s, %d): %s: " fmt,		\
 		current->comm, task_pid_nr(current), sb->s_id,		\
 	       __FILE__, __LINE__, __func__, ##__VA_ARGS__)
 #else
 #define mb_debug(sb, fmt, ...)	no_printk(fmt, ##__VA_ARGS__)
 #endif

 #define EXT4_MB_HISTORY_ALLOC		1	/* allocation */
 #define EXT4_MB_HISTORY_PREALLOC	2	/* preallocated blocks used */

 /*
  * How long mballoc can look for a best extent (in found extents)
  */
 #define MB_DEFAULT_MAX_TO_SCAN		200

 /*
  * How long mballoc must look for a best extent
  */
 #define MB_DEFAULT_MIN_TO_SCAN		10

 /*
  * with 's_mb_stats' allocator will collect stats that will be
  * shown at umount. The collecting costs though!
  */
 #define MB_DEFAULT_STATS		0

 /*
  * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
  * by the stream allocator, which purpose is to pack requests
  * as close each to other as possible to produce smooth I/O traffic
  * We use locality group prealloc space for stream request.
  * We can tune the same via /proc/fs/ext4/<partition>/stream_req
  */
 #define MB_DEFAULT_STREAM_THRESHOLD	16	/* 64K */

 /*
  * for which requests use 2^N search using buddies
  */
 #define MB_DEFAULT_ORDER2_REQS		2

 /*
  * default group prealloc size 512 blocks
  */
 #define MB_DEFAULT_GROUP_PREALLOC	512

 /*
  * Number of groups to search linearly before performing group scanning
  * optimization.
  */
 #define MB_DEFAULT_LINEAR_LIMIT		4

 /*
  * Minimum number of groups that should be present in the file system to perform
  * group scanning optimizations.
  */
 #define MB_DEFAULT_LINEAR_SCAN_THRESHOLD	16

 /*
  * The maximum order upto which CR_BEST_AVAIL_LEN can trim a particular
  * allocation request. Example, if we have an order 7 request and max trim order
  * of 3, we can trim this request upto order 4.
  */
 #define MB_DEFAULT_BEST_AVAIL_TRIM_ORDER	3

 /*
  * Number of valid buddy orders
  */
 #define MB_NUM_ORDERS(sb)		((sb)->s_blocksize_bits + 2)

 struct ext4_free_data {
 	/* this links the free block information from sb_info */
 	struct list_head		efd_list;

 	/* this links the free block information from group_info */
 	struct rb_node			efd_node;

 	/* group which free block extent belongs */
 	ext4_group_t			efd_group;

 	/* free block extent */
 	ext4_grpblk_t			efd_start_cluster;
 	ext4_grpblk_t			efd_count;

 	/* transaction which freed this extent */
 	tid_t				efd_tid;
 };

 struct ext4_prealloc_space {
 	union {
 		struct rb_node	inode_node;		/* for inode PA rbtree */
 		struct list_head	lg_list;	/* for lg PAs */
 	} pa_node;
 	struct list_head	pa_group_list;
 	union {
 		struct list_head pa_tmp_list;
 		struct rcu_head	pa_rcu;
 	} u;
 	spinlock_t		pa_lock;
 	atomic_t		pa_count;
 	unsigned		pa_deleted;
 	ext4_fsblk_t		pa_pstart;	/* phys. block */
 	ext4_lblk_t		pa_lstart;	/* log. block */
 	ext4_grpblk_t		pa_len;		/* len of preallocated chunk */
 	ext4_grpblk_t		pa_free;	/* how many blocks are free */
 	unsigned short		pa_type;	/* pa type. inode or group */
 	union {
 		rwlock_t		*inode_lock;	/* locks the rbtree holding this PA */
 		spinlock_t		*lg_lock;	/* locks the lg list holding this PA */
 	} pa_node_lock;
 	struct inode		*pa_inode;	/* used to get the inode during group discard */
 };

 enum {
 	MB_INODE_PA = 0,
 	MB_GROUP_PA = 1
 };

 struct ext4_free_extent {
 	ext4_lblk_t fe_logical;
 	ext4_grpblk_t fe_start;	/* In cluster units */
 	ext4_group_t fe_group;
 	ext4_grpblk_t fe_len;	/* In cluster units */
 };

 /*
  * Locality group:
  *   we try to group all related changes together
  *   so that writeback can flush/allocate them together as well
  *   Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
  *   (512). We store prealloc space into the hash based on the pa_free blocks
  *   order value.ie, fls(pa_free)-1;
  */
 #define PREALLOC_TB_SIZE 10
 struct ext4_locality_group {
 	/* for allocator */
 	/* to serialize allocates */
 	struct mutex		lg_mutex;
 	/* list of preallocations */
 	struct list_head	lg_prealloc_list[PREALLOC_TB_SIZE];
 	spinlock_t		lg_prealloc_lock;
 };

 struct ext4_allocation_context {
 	struct inode *ac_inode;
 	struct super_block *ac_sb;

 	/* original request */
 	struct ext4_free_extent ac_o_ex;

 	/* goal request (normalized ac_o_ex) */
 	struct ext4_free_extent ac_g_ex;

 	/* the best found extent */
 	struct ext4_free_extent ac_b_ex;

 	/* copy of the best found extent taken before preallocation efforts */
 	struct ext4_free_extent ac_f_ex;

 	/*
 	 * goal len can change in CR1.5, so save the original len. This is
 	 * used while adjusting the PA window and for accounting.
 	 */
 	ext4_grpblk_t	ac_orig_goal_len;

 	__u32 ac_groups_considered;
 	__u32 ac_flags;		/* allocation hints */
 	__u16 ac_groups_scanned;
 	__u16 ac_groups_linear_remaining;
 	__u16 ac_found;
 	__u16 ac_cX_found[EXT4_MB_NUM_CRS];
 	__u16 ac_tail;
 	__u16 ac_buddy;
 	__u8 ac_status;
 	__u8 ac_criteria;
 	__u8 ac_2order;		/* if request is to allocate 2^N blocks and
 				 * N > 0, the field stores N, otherwise 0 */
 	__u8 ac_op;		/* operation, for history only */
 	struct page *ac_bitmap_page;
 	struct page *ac_buddy_page;
 	struct ext4_prealloc_space *ac_pa;
 	struct ext4_locality_group *ac_lg;
 };

 #define AC_STATUS_CONTINUE	1
 #define AC_STATUS_FOUND		2
 #define AC_STATUS_BREAK		3

 struct ext4_buddy {
 	struct page *bd_buddy_page;
 	void *bd_buddy;
 	struct page *bd_bitmap_page;
 	void *bd_bitmap;
 	struct ext4_group_info *bd_info;
 	struct super_block *bd_sb;
 	__u16 bd_blkbits;
 	ext4_group_t bd_group;
 };

 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
 					struct ext4_free_extent *fex)
 {
 	return ext4_group_first_block_no(sb, fex->fe_group) +
 		(fex->fe_start << EXT4_SB(sb)->s_cluster_bits);
 }

 typedef int (*ext4_mballoc_query_range_fn)(
 	struct super_block		*sb,
 	ext4_group_t			agno,
 	ext4_grpblk_t			start,
 	ext4_grpblk_t			len,
 	void				*priv);

 int
 ext4_mballoc_query_range(
 	struct super_block		*sb,
 	ext4_group_t			agno,
 	ext4_grpblk_t			start,
 	ext4_grpblk_t			end,
 	ext4_mballoc_query_range_fn	formatter,
 	void				*priv);

 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* fs/ext4/mballoc.h
	*
	* Written by: Alex Tomas <alex@clusterfs.com>
	*
	*/
	#ifndef _EXT4_MBALLOC_H
	#define _EXT4_MBALLOC_H

	#include <linux/time.h>
	#include <linux/fs.h>
	#include <linux/namei.h>
	#include <linux/quotaops.h>
	#include <linux/buffer_head.h>
	#include <linux/module.h>
	#include <linux/swap.h>
	#include <linux/proc_fs.h>
	#include <linux/pagemap.h>
	#include <linux/seq_file.h>
	#include <linux/blkdev.h>
	#include <linux/mutex.h>
	#include "ext4_jbd2.h"
	#include "ext4.h"

	/*
	* mb_debug() dynamic printk msgs could be used to debug mballoc code.
	*/
	#ifdef CONFIG_EXT4_DEBUG
	#define mb_debug(sb, fmt, ...) \
	pr_debug("[%s/%d] EXT4-fs (%s): (%s, %d): %s: " fmt, \
	current->comm, task_pid_nr(current), sb->s_id, \
	__FILE__, __LINE__, __func__, ##__VA_ARGS__)
	#else
	#define mb_debug(sb, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
	#endif

	#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
	#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */

	/*
	* How long mballoc can look for a best extent (in found extents)
	*/
	#define MB_DEFAULT_MAX_TO_SCAN 200

	/*
	* How long mballoc must look for a best extent
	*/
	#define MB_DEFAULT_MIN_TO_SCAN 10

	/*
	* with 's_mb_stats' allocator will collect stats that will be
	* shown at umount. The collecting costs though!
	*/
	#define MB_DEFAULT_STATS 0

	/*
	* files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
	* by the stream allocator, which purpose is to pack requests
	* as close each to other as possible to produce smooth I/O traffic
	* We use locality group prealloc space for stream request.
	* We can tune the same via /proc/fs/ext4/<partition>/stream_req
	*/
	#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */

	/*
	* for which requests use 2^N search using buddies
	*/
	#define MB_DEFAULT_ORDER2_REQS 2

	/*
	* default group prealloc size 512 blocks
	*/
	#define MB_DEFAULT_GROUP_PREALLOC 512

	/*
	* Number of groups to search linearly before performing group scanning
	* optimization.
	*/
	#define MB_DEFAULT_LINEAR_LIMIT 4

	/*
	* Minimum number of groups that should be present in the file system to perform
	* group scanning optimizations.
	*/
	#define MB_DEFAULT_LINEAR_SCAN_THRESHOLD 16

	/*
	* The maximum order upto which CR_BEST_AVAIL_LEN can trim a particular
	* allocation request. Example, if we have an order 7 request and max trim order
	* of 3, we can trim this request upto order 4.
	*/
	#define MB_DEFAULT_BEST_AVAIL_TRIM_ORDER 3

	/*
	* Number of valid buddy orders
	*/
	#define MB_NUM_ORDERS(sb) ((sb)->s_blocksize_bits + 2)

	struct ext4_free_data {
	/* this links the free block information from sb_info */
	struct list_head efd_list;

	/* this links the free block information from group_info */
	struct rb_node efd_node;

	/* group which free block extent belongs */
	ext4_group_t efd_group;

	/* free block extent */
	ext4_grpblk_t efd_start_cluster;
	ext4_grpblk_t efd_count;

	/* transaction which freed this extent */
	tid_t efd_tid;
	};

	struct ext4_prealloc_space {
	union {
	struct rb_node inode_node; /* for inode PA rbtree */
	struct list_head lg_list; /* for lg PAs */
	} pa_node;
	struct list_head pa_group_list;
	union {
	struct list_head pa_tmp_list;
	struct rcu_head pa_rcu;
	} u;
	spinlock_t pa_lock;
	atomic_t pa_count;
	unsigned pa_deleted;
	ext4_fsblk_t pa_pstart; /* phys. block */
	ext4_lblk_t pa_lstart; /* log. block */
	ext4_grpblk_t pa_len; /* len of preallocated chunk */
	ext4_grpblk_t pa_free; /* how many blocks are free */
	unsigned short pa_type; /* pa type. inode or group */
	union {
	rwlock_t inode_lock; / locks the rbtree holding this PA */
	spinlock_t lg_lock; / locks the lg list holding this PA */
	} pa_node_lock;
	struct inode pa_inode; / used to get the inode during group discard */
	};

	enum {
	MB_INODE_PA = 0,
	MB_GROUP_PA = 1
	};

	struct ext4_free_extent {
	ext4_lblk_t fe_logical;
	ext4_grpblk_t fe_start; /* In cluster units */
	ext4_group_t fe_group;
	ext4_grpblk_t fe_len; /* In cluster units */
	};

	/*
	* Locality group:
	* we try to group all related changes together
	* so that writeback can flush/allocate them together as well
	* Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
	* (512). We store prealloc space into the hash based on the pa_free blocks
	* order value.ie, fls(pa_free)-1;
	*/
	#define PREALLOC_TB_SIZE 10
	struct ext4_locality_group {
	/* for allocator */
	/* to serialize allocates */
	struct mutex lg_mutex;
	/* list of preallocations */
	struct list_head lg_prealloc_list[PREALLOC_TB_SIZE];
	spinlock_t lg_prealloc_lock;
	};

	struct ext4_allocation_context {
	struct inode *ac_inode;
	struct super_block *ac_sb;

	/* original request */
	struct ext4_free_extent ac_o_ex;

	/* goal request (normalized ac_o_ex) */
	struct ext4_free_extent ac_g_ex;

	/* the best found extent */
	struct ext4_free_extent ac_b_ex;

	/* copy of the best found extent taken before preallocation efforts */
	struct ext4_free_extent ac_f_ex;

	/*
	* goal len can change in CR1.5, so save the original len. This is
	* used while adjusting the PA window and for accounting.
	*/
	ext4_grpblk_t ac_orig_goal_len;

	__u32 ac_groups_considered;
	__u32 ac_flags; /* allocation hints */
	__u16 ac_groups_scanned;
	__u16 ac_groups_linear_remaining;
	__u16 ac_found;
	__u16 ac_cX_found[EXT4_MB_NUM_CRS];
	__u16 ac_tail;
	__u16 ac_buddy;
	__u8 ac_status;
	__u8 ac_criteria;
	__u8 ac_2order; /* if request is to allocate 2^N blocks and
	* N > 0, the field stores N, otherwise 0 */
	__u8 ac_op; /* operation, for history only */
	struct page *ac_bitmap_page;
	struct page *ac_buddy_page;
	struct ext4_prealloc_space *ac_pa;
	struct ext4_locality_group *ac_lg;
	};

	#define AC_STATUS_CONTINUE 1
	#define AC_STATUS_FOUND 2
	#define AC_STATUS_BREAK 3

	struct ext4_buddy {
	struct page *bd_buddy_page;
	void *bd_buddy;
	struct page *bd_bitmap_page;
	void *bd_bitmap;
	struct ext4_group_info *bd_info;
	struct super_block *bd_sb;
	__u16 bd_blkbits;
	ext4_group_t bd_group;
	};

	static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
	struct ext4_free_extent *fex)
	{
	return ext4_group_first_block_no(sb, fex->fe_group) +
	(fex->fe_start << EXT4_SB(sb)->s_cluster_bits);
	}

	typedef int (*ext4_mballoc_query_range_fn)(
	struct super_block *sb,
	ext4_group_t agno,
	ext4_grpblk_t start,
	ext4_grpblk_t len,
	void *priv);

	int
	ext4_mballoc_query_range(
	struct super_block *sb,
	ext4_group_t agno,
	ext4_grpblk_t start,
	ext4_grpblk_t end,
	ext4_mballoc_query_range_fn formatter,
	void *priv);

	#endif