263 строки
6.6 KiB
C
263 строки
6.6 KiB
C
/*
|
|
* 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/version.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/marker.h>
|
|
#include <linux/mutex.h>
|
|
#include "ext4_jbd2.h"
|
|
#include "ext4.h"
|
|
|
|
/*
|
|
* with AGGRESSIVE_CHECK allocator runs consistency checks over
|
|
* structures. these checks slow things down a lot
|
|
*/
|
|
#define AGGRESSIVE_CHECK__
|
|
|
|
/*
|
|
* with DOUBLE_CHECK defined mballoc creates persistent in-core
|
|
* bitmaps, maintains and uses them to check for double allocations
|
|
*/
|
|
#define DOUBLE_CHECK__
|
|
|
|
/*
|
|
*/
|
|
#define MB_DEBUG__
|
|
#ifdef MB_DEBUG
|
|
#define mb_debug(fmt, a...) printk(fmt, ##a)
|
|
#else
|
|
#define mb_debug(fmt, a...)
|
|
#endif
|
|
|
|
/*
|
|
* with EXT4_MB_HISTORY mballoc stores last N allocations in memory
|
|
* and you can monitor it in /proc/fs/ext4/<dev>/mb_history
|
|
*/
|
|
#define EXT4_MB_HISTORY
|
|
#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
|
|
#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
|
|
#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
|
|
#define EXT4_MB_HISTORY_FREE 8 /* free */
|
|
|
|
#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
|
|
EXT4_MB_HISTORY_PREALLOC)
|
|
|
|
/*
|
|
* 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
|
|
|
|
/*
|
|
* How many groups mballoc will scan looking for the best chunk
|
|
*/
|
|
#define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5
|
|
|
|
/*
|
|
* with 'ext4_mb_stats' allocator will collect stats that will be
|
|
* shown at umount. The collecting costs though!
|
|
*/
|
|
#define MB_DEFAULT_STATS 1
|
|
|
|
/*
|
|
* 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/<parition>/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
|
|
|
|
|
|
struct ext4_free_data {
|
|
/* this links the free block information from group_info */
|
|
struct rb_node node;
|
|
|
|
/* this links the free block information from ext4_sb_info */
|
|
struct list_head list;
|
|
|
|
/* group which free block extent belongs */
|
|
ext4_group_t group;
|
|
|
|
/* free block extent */
|
|
ext4_grpblk_t start_blk;
|
|
ext4_grpblk_t count;
|
|
|
|
/* transaction which freed this extent */
|
|
tid_t t_tid;
|
|
};
|
|
|
|
struct ext4_prealloc_space {
|
|
struct list_head pa_inode_list;
|
|
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 */
|
|
unsigned short pa_len; /* len of preallocated chunk */
|
|
unsigned short pa_free; /* how many blocks are free */
|
|
unsigned short pa_type; /* pa type. inode or group */
|
|
spinlock_t *pa_obj_lock;
|
|
struct inode *pa_inode; /* hack, for history only */
|
|
};
|
|
|
|
enum {
|
|
MB_INODE_PA = 0,
|
|
MB_GROUP_PA = 1
|
|
};
|
|
|
|
struct ext4_free_extent {
|
|
ext4_lblk_t fe_logical;
|
|
ext4_grpblk_t fe_start;
|
|
ext4_group_t fe_group;
|
|
int fe_len;
|
|
};
|
|
|
|
/*
|
|
* 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 (after normalization) */
|
|
struct ext4_free_extent ac_g_ex;
|
|
|
|
/* the best found extent */
|
|
struct ext4_free_extent ac_b_ex;
|
|
|
|
/* copy of the bext found extent taken before preallocation efforts */
|
|
struct ext4_free_extent ac_f_ex;
|
|
|
|
/* number of iterations done. we have to track to limit searching */
|
|
unsigned long ac_ex_scanned;
|
|
__u16 ac_groups_scanned;
|
|
__u16 ac_found;
|
|
__u16 ac_tail;
|
|
__u16 ac_buddy;
|
|
__u16 ac_flags; /* allocation hints */
|
|
__u8 ac_status;
|
|
__u8 ac_criteria;
|
|
__u8 ac_repeats;
|
|
__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;
|
|
/*
|
|
* pointer to the held semaphore upon successful
|
|
* block allocation
|
|
*/
|
|
struct rw_semaphore *alloc_semp;
|
|
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_mb_history {
|
|
struct ext4_free_extent orig; /* orig allocation */
|
|
struct ext4_free_extent goal; /* goal allocation */
|
|
struct ext4_free_extent result; /* result allocation */
|
|
unsigned pid;
|
|
unsigned ino;
|
|
__u16 found; /* how many extents have been found */
|
|
__u16 groups; /* how many groups have been scanned */
|
|
__u16 tail; /* what tail broke some buddy */
|
|
__u16 buddy; /* buddy the tail ^^^ broke */
|
|
__u16 flags;
|
|
__u8 cr:3; /* which phase the result extent was found at */
|
|
__u8 op:4;
|
|
__u8 merged:1;
|
|
};
|
|
|
|
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;
|
|
struct rw_semaphore *alloc_semp;
|
|
};
|
|
#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
|
|
#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
|
|
|
|
#ifndef EXT4_MB_HISTORY
|
|
static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
|
|
{
|
|
return;
|
|
}
|
|
#endif
|
|
|
|
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
|
|
|
|
static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
|
|
struct ext4_free_extent *fex)
|
|
{
|
|
ext4_fsblk_t block;
|
|
|
|
block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
|
|
+ fex->fe_start
|
|
+ le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
|
|
return block;
|
|
}
|
|
#endif
|