4 * Written by: Alex Tomas <alex@clusterfs.com>
7 #ifndef _EXT4_MBALLOC_H
8 #define _EXT4_MBALLOC_H
10 #include <linux/time.h>
12 #include <linux/namei.h>
13 #include <linux/quotaops.h>
14 #include <linux/buffer_head.h>
15 #include <linux/module.h>
16 #include <linux/swap.h>
17 #include <linux/proc_fs.h>
18 #include <linux/pagemap.h>
19 #include <linux/seq_file.h>
20 #include <linux/blkdev.h>
21 #include <linux/mutex.h>
22 #include "ext4_jbd2.h"
27 #ifdef CONFIG_EXT4_DEBUG
28 extern ushort ext4_mballoc_debug
;
30 #define mb_debug(n, fmt, ...) \
32 if ((n) <= ext4_mballoc_debug) { \
33 printk(KERN_DEBUG "(%s, %d): %s: " fmt, \
34 __FILE__, __LINE__, __func__, ##__VA_ARGS__); \
38 #define mb_debug(n, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
41 #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
42 #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
45 * How long mballoc can look for a best extent (in found extents)
47 #define MB_DEFAULT_MAX_TO_SCAN 200
50 * How long mballoc must look for a best extent
52 #define MB_DEFAULT_MIN_TO_SCAN 10
55 * with 'ext4_mb_stats' allocator will collect stats that will be
56 * shown at umount. The collecting costs though!
58 #define MB_DEFAULT_STATS 0
61 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
62 * by the stream allocator, which purpose is to pack requests
63 * as close each to other as possible to produce smooth I/O traffic
64 * We use locality group prealloc space for stream request.
65 * We can tune the same via /proc/fs/ext4/<parition>/stream_req
67 #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
70 * for which requests use 2^N search using buddies
72 #define MB_DEFAULT_ORDER2_REQS 2
75 * default group prealloc size 512 blocks
77 #define MB_DEFAULT_GROUP_PREALLOC 512
80 struct ext4_free_data
{
81 /* this links the free block information from sb_info */
82 struct list_head efd_list
;
84 /* this links the free block information from group_info */
85 struct rb_node efd_node
;
87 /* group which free block extent belongs */
88 ext4_group_t efd_group
;
90 /* free block extent */
91 ext4_grpblk_t efd_start_cluster
;
92 ext4_grpblk_t efd_count
;
94 /* transaction which freed this extent */
98 struct ext4_prealloc_space
{
99 struct list_head pa_inode_list
;
100 struct list_head pa_group_list
;
102 struct list_head pa_tmp_list
;
103 struct rcu_head pa_rcu
;
108 ext4_fsblk_t pa_pstart
; /* phys. block */
109 ext4_lblk_t pa_lstart
; /* log. block */
110 ext4_grpblk_t pa_len
; /* len of preallocated chunk */
111 ext4_grpblk_t pa_free
; /* how many blocks are free */
112 unsigned short pa_type
; /* pa type. inode or group */
113 spinlock_t
*pa_obj_lock
;
114 struct inode
*pa_inode
; /* hack, for history only */
122 struct ext4_free_extent
{
123 ext4_lblk_t fe_logical
;
124 ext4_grpblk_t fe_start
; /* In cluster units */
125 ext4_group_t fe_group
;
126 ext4_grpblk_t fe_len
; /* In cluster units */
131 * we try to group all related changes together
132 * so that writeback can flush/allocate them together as well
133 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC
134 * (512). We store prealloc space into the hash based on the pa_free blocks
135 * order value.ie, fls(pa_free)-1;
137 #define PREALLOC_TB_SIZE 10
138 struct ext4_locality_group
{
140 /* to serialize allocates */
141 struct mutex lg_mutex
;
142 /* list of preallocations */
143 struct list_head lg_prealloc_list
[PREALLOC_TB_SIZE
];
144 spinlock_t lg_prealloc_lock
;
147 struct ext4_allocation_context
{
148 struct inode
*ac_inode
;
149 struct super_block
*ac_sb
;
151 /* original request */
152 struct ext4_free_extent ac_o_ex
;
154 /* goal request (normalized ac_o_ex) */
155 struct ext4_free_extent ac_g_ex
;
157 /* the best found extent */
158 struct ext4_free_extent ac_b_ex
;
160 /* copy of the best found extent taken before preallocation efforts */
161 struct ext4_free_extent ac_f_ex
;
163 __u16 ac_groups_scanned
;
167 __u16 ac_flags
; /* allocation hints */
170 __u8 ac_2order
; /* if request is to allocate 2^N blocks and
171 * N > 0, the field stores N, otherwise 0 */
172 __u8 ac_op
; /* operation, for history only */
173 struct page
*ac_bitmap_page
;
174 struct page
*ac_buddy_page
;
175 struct ext4_prealloc_space
*ac_pa
;
176 struct ext4_locality_group
*ac_lg
;
179 #define AC_STATUS_CONTINUE 1
180 #define AC_STATUS_FOUND 2
181 #define AC_STATUS_BREAK 3
184 struct page
*bd_buddy_page
;
186 struct page
*bd_bitmap_page
;
188 struct ext4_group_info
*bd_info
;
189 struct super_block
*bd_sb
;
191 ext4_group_t bd_group
;
194 static inline ext4_fsblk_t
ext4_grp_offs_to_block(struct super_block
*sb
,
195 struct ext4_free_extent
*fex
)
197 return ext4_group_first_block_no(sb
, fex
->fe_group
) +
198 (fex
->fe_start
<< EXT4_SB(sb
)->s_cluster_bits
);
201 typedef int (*ext4_mballoc_query_range_fn
)(
202 struct super_block
*sb
,
209 ext4_mballoc_query_range(
210 struct super_block
*sb
,
214 ext4_mballoc_query_range_fn formatter
,