Commit | Line | Data |
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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 | 21 | #include <linux/blkdev.h> |
920313a7 | 22 | #include <linux/mutex.h> |
8f6e39a7 MC |
23 | #include "ext4_jbd2.h" |
24 | #include "ext4.h" | |
8f6e39a7 MC |
25 | |
26 | /* | |
27 | * with AGGRESSIVE_CHECK allocator runs consistency checks over | |
28 | * structures. these checks slow things down a lot | |
29 | */ | |
30 | #define AGGRESSIVE_CHECK__ | |
31 | ||
32 | /* | |
33 | * with DOUBLE_CHECK defined mballoc creates persistent in-core | |
34 | * bitmaps, maintains and uses them to check for double allocations | |
35 | */ | |
36 | #define DOUBLE_CHECK__ | |
37 | ||
38 | /* | |
39 | */ | |
6ba495e9 TT |
40 | #ifdef CONFIG_EXT4_DEBUG |
41 | extern u8 mb_enable_debug; | |
42 | ||
43 | #define mb_debug(n, fmt, a...) \ | |
44 | do { \ | |
45 | if ((n) <= mb_enable_debug) { \ | |
46 | printk(KERN_DEBUG "(%s, %d): %s: ", \ | |
47 | __FILE__, __LINE__, __func__); \ | |
48 | printk(fmt, ## a); \ | |
49 | } \ | |
50 | } while (0) | |
8f6e39a7 | 51 | #else |
6ba495e9 | 52 | #define mb_debug(n, fmt, a...) |
8f6e39a7 MC |
53 | #endif |
54 | ||
55 | /* | |
56 | * with EXT4_MB_HISTORY mballoc stores last N allocations in memory | |
57 | * and you can monitor it in /proc/fs/ext4/<dev>/mb_history | |
58 | */ | |
59 | #define EXT4_MB_HISTORY | |
60 | #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ | |
61 | #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ | |
62 | #define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */ | |
63 | #define EXT4_MB_HISTORY_FREE 8 /* free */ | |
64 | ||
65 | #define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \ | |
66 | EXT4_MB_HISTORY_PREALLOC) | |
67 | ||
68 | /* | |
69 | * How long mballoc can look for a best extent (in found extents) | |
70 | */ | |
71 | #define MB_DEFAULT_MAX_TO_SCAN 200 | |
72 | ||
73 | /* | |
74 | * How long mballoc must look for a best extent | |
75 | */ | |
76 | #define MB_DEFAULT_MIN_TO_SCAN 10 | |
77 | ||
78 | /* | |
79 | * How many groups mballoc will scan looking for the best chunk | |
80 | */ | |
81 | #define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5 | |
82 | ||
83 | /* | |
84 | * with 'ext4_mb_stats' allocator will collect stats that will be | |
85 | * shown at umount. The collecting costs though! | |
86 | */ | |
87 | #define MB_DEFAULT_STATS 1 | |
88 | ||
89 | /* | |
90 | * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served | |
91 | * by the stream allocator, which purpose is to pack requests | |
92 | * as close each to other as possible to produce smooth I/O traffic | |
93 | * We use locality group prealloc space for stream request. | |
94 | * We can tune the same via /proc/fs/ext4/<parition>/stream_req | |
95 | */ | |
96 | #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ | |
97 | ||
98 | /* | |
99 | * for which requests use 2^N search using buddies | |
100 | */ | |
101 | #define MB_DEFAULT_ORDER2_REQS 2 | |
102 | ||
103 | /* | |
104 | * default group prealloc size 512 blocks | |
105 | */ | |
106 | #define MB_DEFAULT_GROUP_PREALLOC 512 | |
107 | ||
8f6e39a7 | 108 | |
c894058d AK |
109 | struct ext4_free_data { |
110 | /* this links the free block information from group_info */ | |
111 | struct rb_node node; | |
8f6e39a7 | 112 | |
c894058d | 113 | /* this links the free block information from ext4_sb_info */ |
8f6e39a7 | 114 | struct list_head list; |
c894058d AK |
115 | |
116 | /* group which free block extent belongs */ | |
117 | ext4_group_t group; | |
118 | ||
119 | /* free block extent */ | |
120 | ext4_grpblk_t start_blk; | |
121 | ext4_grpblk_t count; | |
122 | ||
123 | /* transaction which freed this extent */ | |
124 | tid_t t_tid; | |
8f6e39a7 MC |
125 | }; |
126 | ||
8f6e39a7 MC |
127 | struct ext4_prealloc_space { |
128 | struct list_head pa_inode_list; | |
129 | struct list_head pa_group_list; | |
130 | union { | |
131 | struct list_head pa_tmp_list; | |
132 | struct rcu_head pa_rcu; | |
133 | } u; | |
134 | spinlock_t pa_lock; | |
135 | atomic_t pa_count; | |
136 | unsigned pa_deleted; | |
137 | ext4_fsblk_t pa_pstart; /* phys. block */ | |
138 | ext4_lblk_t pa_lstart; /* log. block */ | |
a36b4498 ES |
139 | ext4_grpblk_t pa_len; /* len of preallocated chunk */ |
140 | ext4_grpblk_t pa_free; /* how many blocks are free */ | |
cc0fb9ad | 141 | unsigned short pa_type; /* pa type. inode or group */ |
8f6e39a7 MC |
142 | spinlock_t *pa_obj_lock; |
143 | struct inode *pa_inode; /* hack, for history only */ | |
144 | }; | |
145 | ||
cc0fb9ad AK |
146 | enum { |
147 | MB_INODE_PA = 0, | |
148 | MB_GROUP_PA = 1 | |
149 | }; | |
8f6e39a7 MC |
150 | |
151 | struct ext4_free_extent { | |
152 | ext4_lblk_t fe_logical; | |
153 | ext4_grpblk_t fe_start; | |
154 | ext4_group_t fe_group; | |
a36b4498 | 155 | ext4_grpblk_t fe_len; |
8f6e39a7 MC |
156 | }; |
157 | ||
158 | /* | |
159 | * Locality group: | |
160 | * we try to group all related changes together | |
161 | * so that writeback can flush/allocate them together as well | |
6be2ded1 AK |
162 | * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC |
163 | * (512). We store prealloc space into the hash based on the pa_free blocks | |
164 | * order value.ie, fls(pa_free)-1; | |
8f6e39a7 | 165 | */ |
6be2ded1 | 166 | #define PREALLOC_TB_SIZE 10 |
8f6e39a7 MC |
167 | struct ext4_locality_group { |
168 | /* for allocator */ | |
6be2ded1 AK |
169 | /* to serialize allocates */ |
170 | struct mutex lg_mutex; | |
171 | /* list of preallocations */ | |
172 | struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; | |
8f6e39a7 MC |
173 | spinlock_t lg_prealloc_lock; |
174 | }; | |
175 | ||
176 | struct ext4_allocation_context { | |
177 | struct inode *ac_inode; | |
178 | struct super_block *ac_sb; | |
179 | ||
180 | /* original request */ | |
181 | struct ext4_free_extent ac_o_ex; | |
182 | ||
183 | /* goal request (after normalization) */ | |
184 | struct ext4_free_extent ac_g_ex; | |
185 | ||
186 | /* the best found extent */ | |
187 | struct ext4_free_extent ac_b_ex; | |
188 | ||
189 | /* copy of the bext found extent taken before preallocation efforts */ | |
190 | struct ext4_free_extent ac_f_ex; | |
191 | ||
192 | /* number of iterations done. we have to track to limit searching */ | |
193 | unsigned long ac_ex_scanned; | |
194 | __u16 ac_groups_scanned; | |
195 | __u16 ac_found; | |
196 | __u16 ac_tail; | |
197 | __u16 ac_buddy; | |
198 | __u16 ac_flags; /* allocation hints */ | |
199 | __u8 ac_status; | |
200 | __u8 ac_criteria; | |
201 | __u8 ac_repeats; | |
202 | __u8 ac_2order; /* if request is to allocate 2^N blocks and | |
203 | * N > 0, the field stores N, otherwise 0 */ | |
204 | __u8 ac_op; /* operation, for history only */ | |
205 | struct page *ac_bitmap_page; | |
206 | struct page *ac_buddy_page; | |
8556e8f3 AK |
207 | /* |
208 | * pointer to the held semaphore upon successful | |
209 | * block allocation | |
210 | */ | |
211 | struct rw_semaphore *alloc_semp; | |
8f6e39a7 MC |
212 | struct ext4_prealloc_space *ac_pa; |
213 | struct ext4_locality_group *ac_lg; | |
214 | }; | |
215 | ||
216 | #define AC_STATUS_CONTINUE 1 | |
217 | #define AC_STATUS_FOUND 2 | |
218 | #define AC_STATUS_BREAK 3 | |
219 | ||
220 | struct ext4_mb_history { | |
221 | struct ext4_free_extent orig; /* orig allocation */ | |
222 | struct ext4_free_extent goal; /* goal allocation */ | |
223 | struct ext4_free_extent result; /* result allocation */ | |
224 | unsigned pid; | |
225 | unsigned ino; | |
226 | __u16 found; /* how many extents have been found */ | |
227 | __u16 groups; /* how many groups have been scanned */ | |
228 | __u16 tail; /* what tail broke some buddy */ | |
229 | __u16 buddy; /* buddy the tail ^^^ broke */ | |
230 | __u16 flags; | |
231 | __u8 cr:3; /* which phase the result extent was found at */ | |
232 | __u8 op:4; | |
233 | __u8 merged:1; | |
234 | }; | |
235 | ||
236 | struct ext4_buddy { | |
237 | struct page *bd_buddy_page; | |
238 | void *bd_buddy; | |
239 | struct page *bd_bitmap_page; | |
240 | void *bd_bitmap; | |
241 | struct ext4_group_info *bd_info; | |
242 | struct super_block *bd_sb; | |
243 | __u16 bd_blkbits; | |
244 | ext4_group_t bd_group; | |
920313a7 | 245 | struct rw_semaphore *alloc_semp; |
8f6e39a7 MC |
246 | }; |
247 | #define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap) | |
248 | #define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy) | |
249 | ||
250 | #ifndef EXT4_MB_HISTORY | |
251 | static inline void ext4_mb_store_history(struct ext4_allocation_context *ac) | |
252 | { | |
253 | return; | |
254 | } | |
8f6e39a7 MC |
255 | #endif |
256 | ||
257 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) | |
258 | ||
c3a326a6 | 259 | static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, |
8f6e39a7 MC |
260 | struct ext4_free_extent *fex) |
261 | { | |
262 | ext4_fsblk_t block; | |
263 | ||
264 | block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb) | |
265 | + fex->fe_start | |
266 | + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); | |
267 | return block; | |
268 | } | |
269 | #endif |