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8f6e39a7 MC |
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> | |
8a0aba73 TT |
21 | #include <linux/blkdev.h> |
22 | #include <linux/marker.h> | |
8f6e39a7 MC |
23 | #include "ext4_jbd2.h" |
24 | #include "ext4.h" | |
25 | #include "group.h" | |
26 | ||
27 | /* | |
28 | * with AGGRESSIVE_CHECK allocator runs consistency checks over | |
29 | * structures. these checks slow things down a lot | |
30 | */ | |
31 | #define AGGRESSIVE_CHECK__ | |
32 | ||
33 | /* | |
34 | * with DOUBLE_CHECK defined mballoc creates persistent in-core | |
35 | * bitmaps, maintains and uses them to check for double allocations | |
36 | */ | |
37 | #define DOUBLE_CHECK__ | |
38 | ||
39 | /* | |
40 | */ | |
41 | #define MB_DEBUG__ | |
42 | #ifdef MB_DEBUG | |
43 | #define mb_debug(fmt, a...) printk(fmt, ##a) | |
44 | #else | |
45 | #define mb_debug(fmt, a...) | |
46 | #endif | |
47 | ||
48 | /* | |
49 | * with EXT4_MB_HISTORY mballoc stores last N allocations in memory | |
50 | * and you can monitor it in /proc/fs/ext4/<dev>/mb_history | |
51 | */ | |
52 | #define EXT4_MB_HISTORY | |
53 | #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ | |
54 | #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ | |
55 | #define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */ | |
56 | #define EXT4_MB_HISTORY_FREE 8 /* free */ | |
57 | ||
58 | #define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \ | |
59 | EXT4_MB_HISTORY_PREALLOC) | |
60 | ||
61 | /* | |
62 | * How long mballoc can look for a best extent (in found extents) | |
63 | */ | |
64 | #define MB_DEFAULT_MAX_TO_SCAN 200 | |
65 | ||
66 | /* | |
67 | * How long mballoc must look for a best extent | |
68 | */ | |
69 | #define MB_DEFAULT_MIN_TO_SCAN 10 | |
70 | ||
71 | /* | |
72 | * How many groups mballoc will scan looking for the best chunk | |
73 | */ | |
74 | #define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5 | |
75 | ||
76 | /* | |
77 | * with 'ext4_mb_stats' allocator will collect stats that will be | |
78 | * shown at umount. The collecting costs though! | |
79 | */ | |
80 | #define MB_DEFAULT_STATS 1 | |
81 | ||
82 | /* | |
83 | * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served | |
84 | * by the stream allocator, which purpose is to pack requests | |
85 | * as close each to other as possible to produce smooth I/O traffic | |
86 | * We use locality group prealloc space for stream request. | |
87 | * We can tune the same via /proc/fs/ext4/<parition>/stream_req | |
88 | */ | |
89 | #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ | |
90 | ||
91 | /* | |
92 | * for which requests use 2^N search using buddies | |
93 | */ | |
94 | #define MB_DEFAULT_ORDER2_REQS 2 | |
95 | ||
96 | /* | |
97 | * default group prealloc size 512 blocks | |
98 | */ | |
99 | #define MB_DEFAULT_GROUP_PREALLOC 512 | |
100 | ||
101 | static struct kmem_cache *ext4_pspace_cachep; | |
102 | static struct kmem_cache *ext4_ac_cachep; | |
c894058d | 103 | static struct kmem_cache *ext4_free_ext_cachep; |
8f6e39a7 | 104 | |
c894058d AK |
105 | struct ext4_free_data { |
106 | /* this links the free block information from group_info */ | |
107 | struct rb_node node; | |
8f6e39a7 | 108 | |
c894058d | 109 | /* this links the free block information from ext4_sb_info */ |
8f6e39a7 | 110 | struct list_head list; |
c894058d AK |
111 | |
112 | /* group which free block extent belongs */ | |
113 | ext4_group_t group; | |
114 | ||
115 | /* free block extent */ | |
116 | ext4_grpblk_t start_blk; | |
117 | ext4_grpblk_t count; | |
118 | ||
119 | /* transaction which freed this extent */ | |
120 | tid_t t_tid; | |
8f6e39a7 MC |
121 | }; |
122 | ||
123 | struct ext4_group_info { | |
124 | unsigned long bb_state; | |
c894058d | 125 | struct rb_root bb_free_root; |
8f6e39a7 MC |
126 | unsigned short bb_first_free; |
127 | unsigned short bb_free; | |
128 | unsigned short bb_fragments; | |
129 | struct list_head bb_prealloc_list; | |
130 | #ifdef DOUBLE_CHECK | |
131 | void *bb_bitmap; | |
132 | #endif | |
133 | unsigned short bb_counters[]; | |
134 | }; | |
135 | ||
136 | #define EXT4_GROUP_INFO_NEED_INIT_BIT 0 | |
137 | #define EXT4_GROUP_INFO_LOCKED_BIT 1 | |
138 | ||
139 | #define EXT4_MB_GRP_NEED_INIT(grp) \ | |
140 | (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state))) | |
141 | ||
142 | ||
143 | struct ext4_prealloc_space { | |
144 | struct list_head pa_inode_list; | |
145 | struct list_head pa_group_list; | |
146 | union { | |
147 | struct list_head pa_tmp_list; | |
148 | struct rcu_head pa_rcu; | |
149 | } u; | |
150 | spinlock_t pa_lock; | |
151 | atomic_t pa_count; | |
152 | unsigned pa_deleted; | |
153 | ext4_fsblk_t pa_pstart; /* phys. block */ | |
154 | ext4_lblk_t pa_lstart; /* log. block */ | |
155 | unsigned short pa_len; /* len of preallocated chunk */ | |
156 | unsigned short pa_free; /* how many blocks are free */ | |
157 | unsigned short pa_linear; /* consumed in one direction | |
158 | * strictly, for grp prealloc */ | |
159 | spinlock_t *pa_obj_lock; | |
160 | struct inode *pa_inode; /* hack, for history only */ | |
161 | }; | |
162 | ||
163 | ||
164 | struct ext4_free_extent { | |
165 | ext4_lblk_t fe_logical; | |
166 | ext4_grpblk_t fe_start; | |
167 | ext4_group_t fe_group; | |
168 | int fe_len; | |
169 | }; | |
170 | ||
171 | /* | |
172 | * Locality group: | |
173 | * we try to group all related changes together | |
174 | * so that writeback can flush/allocate them together as well | |
6be2ded1 AK |
175 | * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC |
176 | * (512). We store prealloc space into the hash based on the pa_free blocks | |
177 | * order value.ie, fls(pa_free)-1; | |
8f6e39a7 | 178 | */ |
6be2ded1 | 179 | #define PREALLOC_TB_SIZE 10 |
8f6e39a7 MC |
180 | struct ext4_locality_group { |
181 | /* for allocator */ | |
6be2ded1 AK |
182 | /* to serialize allocates */ |
183 | struct mutex lg_mutex; | |
184 | /* list of preallocations */ | |
185 | struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; | |
8f6e39a7 MC |
186 | spinlock_t lg_prealloc_lock; |
187 | }; | |
188 | ||
189 | struct ext4_allocation_context { | |
190 | struct inode *ac_inode; | |
191 | struct super_block *ac_sb; | |
192 | ||
193 | /* original request */ | |
194 | struct ext4_free_extent ac_o_ex; | |
195 | ||
196 | /* goal request (after normalization) */ | |
197 | struct ext4_free_extent ac_g_ex; | |
198 | ||
199 | /* the best found extent */ | |
200 | struct ext4_free_extent ac_b_ex; | |
201 | ||
202 | /* copy of the bext found extent taken before preallocation efforts */ | |
203 | struct ext4_free_extent ac_f_ex; | |
204 | ||
205 | /* number of iterations done. we have to track to limit searching */ | |
206 | unsigned long ac_ex_scanned; | |
207 | __u16 ac_groups_scanned; | |
208 | __u16 ac_found; | |
209 | __u16 ac_tail; | |
210 | __u16 ac_buddy; | |
211 | __u16 ac_flags; /* allocation hints */ | |
212 | __u8 ac_status; | |
213 | __u8 ac_criteria; | |
214 | __u8 ac_repeats; | |
215 | __u8 ac_2order; /* if request is to allocate 2^N blocks and | |
216 | * N > 0, the field stores N, otherwise 0 */ | |
217 | __u8 ac_op; /* operation, for history only */ | |
218 | struct page *ac_bitmap_page; | |
219 | struct page *ac_buddy_page; | |
220 | struct ext4_prealloc_space *ac_pa; | |
221 | struct ext4_locality_group *ac_lg; | |
222 | }; | |
223 | ||
224 | #define AC_STATUS_CONTINUE 1 | |
225 | #define AC_STATUS_FOUND 2 | |
226 | #define AC_STATUS_BREAK 3 | |
227 | ||
228 | struct ext4_mb_history { | |
229 | struct ext4_free_extent orig; /* orig allocation */ | |
230 | struct ext4_free_extent goal; /* goal allocation */ | |
231 | struct ext4_free_extent result; /* result allocation */ | |
232 | unsigned pid; | |
233 | unsigned ino; | |
234 | __u16 found; /* how many extents have been found */ | |
235 | __u16 groups; /* how many groups have been scanned */ | |
236 | __u16 tail; /* what tail broke some buddy */ | |
237 | __u16 buddy; /* buddy the tail ^^^ broke */ | |
238 | __u16 flags; | |
239 | __u8 cr:3; /* which phase the result extent was found at */ | |
240 | __u8 op:4; | |
241 | __u8 merged:1; | |
242 | }; | |
243 | ||
244 | struct ext4_buddy { | |
245 | struct page *bd_buddy_page; | |
246 | void *bd_buddy; | |
247 | struct page *bd_bitmap_page; | |
248 | void *bd_bitmap; | |
249 | struct ext4_group_info *bd_info; | |
250 | struct super_block *bd_sb; | |
251 | __u16 bd_blkbits; | |
252 | ext4_group_t bd_group; | |
253 | }; | |
254 | #define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap) | |
255 | #define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy) | |
256 | ||
257 | #ifndef EXT4_MB_HISTORY | |
258 | static inline void ext4_mb_store_history(struct ext4_allocation_context *ac) | |
259 | { | |
260 | return; | |
261 | } | |
262 | #else | |
263 | static void ext4_mb_store_history(struct ext4_allocation_context *ac); | |
264 | #endif | |
265 | ||
266 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) | |
267 | ||
8f6e39a7 MC |
268 | struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t); |
269 | ||
270 | static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, | |
271 | ext4_group_t group); | |
8f6e39a7 MC |
272 | static void ext4_mb_return_to_preallocation(struct inode *inode, |
273 | struct ext4_buddy *e4b, sector_t block, | |
274 | int count); | |
275 | static void ext4_mb_put_pa(struct ext4_allocation_context *, | |
276 | struct super_block *, struct ext4_prealloc_space *pa); | |
277 | static int ext4_mb_init_per_dev_proc(struct super_block *sb); | |
278 | static int ext4_mb_destroy_per_dev_proc(struct super_block *sb); | |
3e624fc7 | 279 | static void release_blocks_on_commit(journal_t *journal, transaction_t *txn); |
8f6e39a7 MC |
280 | |
281 | ||
282 | static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group) | |
283 | { | |
284 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); | |
285 | ||
286 | bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state)); | |
287 | } | |
288 | ||
289 | static inline void ext4_unlock_group(struct super_block *sb, | |
290 | ext4_group_t group) | |
291 | { | |
292 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); | |
293 | ||
294 | bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state)); | |
295 | } | |
296 | ||
297 | static inline int ext4_is_group_locked(struct super_block *sb, | |
298 | ext4_group_t group) | |
299 | { | |
300 | struct ext4_group_info *grinfo = ext4_get_group_info(sb, group); | |
301 | ||
302 | return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT, | |
303 | &(grinfo->bb_state)); | |
304 | } | |
305 | ||
306 | static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, | |
307 | struct ext4_free_extent *fex) | |
308 | { | |
309 | ext4_fsblk_t block; | |
310 | ||
311 | block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb) | |
312 | + fex->fe_start | |
313 | + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); | |
314 | return block; | |
315 | } | |
316 | #endif |