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-rw-r--r--fs/ext4/mballoc.h304
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diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
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1/*
2 * fs/ext4/mballoc.h
3 *
4 * Written by: Alex Tomas <alex@clusterfs.com>
5 *
6 */
7#ifndef _EXT4_MBALLOC_H
8#define _EXT4_MBALLOC_H
9
10#include <linux/time.h>
11#include <linux/fs.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/version.h>
21#include "ext4_jbd2.h"
22#include "ext4.h"
23#include "group.h"
24
25/*
26 * with AGGRESSIVE_CHECK allocator runs consistency checks over
27 * structures. these checks slow things down a lot
28 */
29#define AGGRESSIVE_CHECK__
30
31/*
32 * with DOUBLE_CHECK defined mballoc creates persistent in-core
33 * bitmaps, maintains and uses them to check for double allocations
34 */
35#define DOUBLE_CHECK__
36
37/*
38 */
39#define MB_DEBUG__
40#ifdef MB_DEBUG
41#define mb_debug(fmt, a...) printk(fmt, ##a)
42#else
43#define mb_debug(fmt, a...)
44#endif
45
46/*
47 * with EXT4_MB_HISTORY mballoc stores last N allocations in memory
48 * and you can monitor it in /proc/fs/ext4/<dev>/mb_history
49 */
50#define EXT4_MB_HISTORY
51#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
52#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
53#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
54#define EXT4_MB_HISTORY_FREE 8 /* free */
55
56#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
57 EXT4_MB_HISTORY_PREALLOC)
58
59/*
60 * How long mballoc can look for a best extent (in found extents)
61 */
62#define MB_DEFAULT_MAX_TO_SCAN 200
63
64/*
65 * How long mballoc must look for a best extent
66 */
67#define MB_DEFAULT_MIN_TO_SCAN 10
68
69/*
70 * How many groups mballoc will scan looking for the best chunk
71 */
72#define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5
73
74/*
75 * with 'ext4_mb_stats' allocator will collect stats that will be
76 * shown at umount. The collecting costs though!
77 */
78#define MB_DEFAULT_STATS 1
79
80/*
81 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
82 * by the stream allocator, which purpose is to pack requests
83 * as close each to other as possible to produce smooth I/O traffic
84 * We use locality group prealloc space for stream request.
85 * We can tune the same via /proc/fs/ext4/<parition>/stream_req
86 */
87#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
88
89/*
90 * for which requests use 2^N search using buddies
91 */
92#define MB_DEFAULT_ORDER2_REQS 2
93
94/*
95 * default group prealloc size 512 blocks
96 */
97#define MB_DEFAULT_GROUP_PREALLOC 512
98
99static struct kmem_cache *ext4_pspace_cachep;
100static struct kmem_cache *ext4_ac_cachep;
101
102#ifdef EXT4_BB_MAX_BLOCKS
103#undef EXT4_BB_MAX_BLOCKS
104#endif
105#define EXT4_BB_MAX_BLOCKS 30
106
107struct ext4_free_metadata {
108 ext4_group_t group;
109 unsigned short num;
110 ext4_grpblk_t blocks[EXT4_BB_MAX_BLOCKS];
111 struct list_head list;
112};
113
114struct ext4_group_info {
115 unsigned long bb_state;
116 unsigned long bb_tid;
117 struct ext4_free_metadata *bb_md_cur;
118 unsigned short bb_first_free;
119 unsigned short bb_free;
120 unsigned short bb_fragments;
121 struct list_head bb_prealloc_list;
122#ifdef DOUBLE_CHECK
123 void *bb_bitmap;
124#endif
125 unsigned short bb_counters[];
126};
127
128#define EXT4_GROUP_INFO_NEED_INIT_BIT 0
129#define EXT4_GROUP_INFO_LOCKED_BIT 1
130
131#define EXT4_MB_GRP_NEED_INIT(grp) \
132 (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
133
134
135struct ext4_prealloc_space {
136 struct list_head pa_inode_list;
137 struct list_head pa_group_list;
138 union {
139 struct list_head pa_tmp_list;
140 struct rcu_head pa_rcu;
141 } u;
142 spinlock_t pa_lock;
143 atomic_t pa_count;
144 unsigned pa_deleted;
145 ext4_fsblk_t pa_pstart; /* phys. block */
146 ext4_lblk_t pa_lstart; /* log. block */
147 unsigned short pa_len; /* len of preallocated chunk */
148 unsigned short pa_free; /* how many blocks are free */
149 unsigned short pa_linear; /* consumed in one direction
150 * strictly, for grp prealloc */
151 spinlock_t *pa_obj_lock;
152 struct inode *pa_inode; /* hack, for history only */
153};
154
155
156struct ext4_free_extent {
157 ext4_lblk_t fe_logical;
158 ext4_grpblk_t fe_start;
159 ext4_group_t fe_group;
160 int fe_len;
161};
162
163/*
164 * Locality group:
165 * we try to group all related changes together
166 * so that writeback can flush/allocate them together as well
167 */
168struct ext4_locality_group {
169 /* for allocator */
170 struct mutex lg_mutex; /* to serialize allocates */
171 struct list_head lg_prealloc_list;/* list of preallocations */
172 spinlock_t lg_prealloc_lock;
173};
174
175struct ext4_allocation_context {
176 struct inode *ac_inode;
177 struct super_block *ac_sb;
178
179 /* original request */
180 struct ext4_free_extent ac_o_ex;
181
182 /* goal request (after normalization) */
183 struct ext4_free_extent ac_g_ex;
184
185 /* the best found extent */
186 struct ext4_free_extent ac_b_ex;
187
188 /* copy of the bext found extent taken before preallocation efforts */
189 struct ext4_free_extent ac_f_ex;
190
191 /* number of iterations done. we have to track to limit searching */
192 unsigned long ac_ex_scanned;
193 __u16 ac_groups_scanned;
194 __u16 ac_found;
195 __u16 ac_tail;
196 __u16 ac_buddy;
197 __u16 ac_flags; /* allocation hints */
198 __u8 ac_status;
199 __u8 ac_criteria;
200 __u8 ac_repeats;
201 __u8 ac_2order; /* if request is to allocate 2^N blocks and
202 * N > 0, the field stores N, otherwise 0 */
203 __u8 ac_op; /* operation, for history only */
204 struct page *ac_bitmap_page;
205 struct page *ac_buddy_page;
206 struct ext4_prealloc_space *ac_pa;
207 struct ext4_locality_group *ac_lg;
208};
209
210#define AC_STATUS_CONTINUE 1
211#define AC_STATUS_FOUND 2
212#define AC_STATUS_BREAK 3
213
214struct ext4_mb_history {
215 struct ext4_free_extent orig; /* orig allocation */
216 struct ext4_free_extent goal; /* goal allocation */
217 struct ext4_free_extent result; /* result allocation */
218 unsigned pid;
219 unsigned ino;
220 __u16 found; /* how many extents have been found */
221 __u16 groups; /* how many groups have been scanned */
222 __u16 tail; /* what tail broke some buddy */
223 __u16 buddy; /* buddy the tail ^^^ broke */
224 __u16 flags;
225 __u8 cr:3; /* which phase the result extent was found at */
226 __u8 op:4;
227 __u8 merged:1;
228};
229
230struct ext4_buddy {
231 struct page *bd_buddy_page;
232 void *bd_buddy;
233 struct page *bd_bitmap_page;
234 void *bd_bitmap;
235 struct ext4_group_info *bd_info;
236 struct super_block *bd_sb;
237 __u16 bd_blkbits;
238 ext4_group_t bd_group;
239};
240#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
241#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
242
243#ifndef EXT4_MB_HISTORY
244static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
245{
246 return;
247}
248#else
249static void ext4_mb_store_history(struct ext4_allocation_context *ac);
250#endif
251
252#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
253
254static struct proc_dir_entry *proc_root_ext4;
255struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t);
256
257static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
258 ext4_group_t group);
259static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *);
260static void ext4_mb_free_committed_blocks(struct super_block *);
261static void ext4_mb_return_to_preallocation(struct inode *inode,
262 struct ext4_buddy *e4b, sector_t block,
263 int count);
264static void ext4_mb_put_pa(struct ext4_allocation_context *,
265 struct super_block *, struct ext4_prealloc_space *pa);
266static int ext4_mb_init_per_dev_proc(struct super_block *sb);
267static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
268
269
270static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
271{
272 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
273
274 bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
275}
276
277static inline void ext4_unlock_group(struct super_block *sb,
278 ext4_group_t group)
279{
280 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
281
282 bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
283}
284
285static inline int ext4_is_group_locked(struct super_block *sb,
286 ext4_group_t group)
287{
288 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
289
290 return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
291 &(grinfo->bb_state));
292}
293
294static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
295 struct ext4_free_extent *fex)
296{
297 ext4_fsblk_t block;
298
299 block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
300 + fex->fe_start
301 + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
302 return block;
303}
304#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-23 08:53:02 -0500