1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/ext4/mballoc.h 4 * 5 * Written by: Alex Tomas <alex@clusterfs.com> 6 * 7 */ 8 #ifndef _EXT4_MBALLOC_H 9 #define _EXT4_MBALLOC_H 10 11 #include <linux/time.h> 12 #include <linux/fs.h> 13 #include <linux/namei.h> 14 #include <linux/quotaops.h> 15 #include <linux/buffer_head.h> 16 #include <linux/module.h> 17 #include <linux/swap.h> 18 #include <linux/proc_fs.h> 19 #include <linux/pagemap.h> 20 #include <linux/seq_file.h> 21 #include <linux/blkdev.h> 22 #include <linux/mutex.h> 23 #include "ext4_jbd2.h" 24 #include "ext4.h" 25 26 /* 27 * mb_debug() dynamic printk msgs could be used to debug mballoc code. 28 */ 29 #ifdef CONFIG_EXT4_DEBUG 30 #define mb_debug(sb, fmt, ...) \ 31 pr_debug("[%s/%d] EXT4-fs (%s): (%s, %d): %s: " fmt, \ 32 current->comm, task_pid_nr(current), sb->s_id, \ 33 __FILE__, __LINE__, __func__, ##__VA_ARGS__) 34 #else 35 #define mb_debug(sb, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 36 #endif 37 38 #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ 39 #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ 40 41 /* 42 * How long mballoc can look for a best extent (in found extents) 43 */ 44 #define MB_DEFAULT_MAX_TO_SCAN 200 45 46 /* 47 * How long mballoc must look for a best extent 48 */ 49 #define MB_DEFAULT_MIN_TO_SCAN 10 50 51 /* 52 * with 's_mb_stats' allocator will collect stats that will be 53 * shown at umount. The collecting costs though! 54 */ 55 #define MB_DEFAULT_STATS 0 56 57 /* 58 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served 59 * by the stream allocator, which purpose is to pack requests 60 * as close each to other as possible to produce smooth I/O traffic 61 * We use locality group prealloc space for stream request. 62 * We can tune the same via /proc/fs/ext4/<partition>/stream_req 63 */ 64 #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ 65 66 /* 67 * for which requests use 2^N search using buddies 68 */ 69 #define MB_DEFAULT_ORDER2_REQS 2 70 71 /* 72 * default group prealloc size 512 blocks 73 */ 74 #define MB_DEFAULT_GROUP_PREALLOC 512 75 76 /* 77 * Number of groups to search linearly before performing group scanning 78 * optimization. 79 */ 80 #define MB_DEFAULT_LINEAR_LIMIT 4 81 82 /* 83 * Minimum number of groups that should be present in the file system to perform 84 * group scanning optimizations. 85 */ 86 #define MB_DEFAULT_LINEAR_SCAN_THRESHOLD 16 87 88 /* 89 * The maximum order upto which CR_BEST_AVAIL_LEN can trim a particular 90 * allocation request. Example, if we have an order 7 request and max trim order 91 * of 3, we can trim this request upto order 4. 92 */ 93 #define MB_DEFAULT_BEST_AVAIL_TRIM_ORDER 3 94 95 /* 96 * Number of valid buddy orders 97 */ 98 #define MB_NUM_ORDERS(sb) ((sb)->s_blocksize_bits + 2) 99 100 struct ext4_free_data { 101 /* this links the free block information from sb_info */ 102 struct list_head efd_list; 103 104 /* this links the free block information from group_info */ 105 struct rb_node efd_node; 106 107 /* group which free block extent belongs */ 108 ext4_group_t efd_group; 109 110 /* free block extent */ 111 ext4_grpblk_t efd_start_cluster; 112 ext4_grpblk_t efd_count; 113 114 /* transaction which freed this extent */ 115 tid_t efd_tid; 116 }; 117 118 struct ext4_prealloc_space { 119 union { 120 struct rb_node inode_node; /* for inode PA rbtree */ 121 struct list_head lg_list; /* for lg PAs */ 122 } pa_node; 123 struct list_head pa_group_list; 124 union { 125 struct list_head pa_tmp_list; 126 struct rcu_head pa_rcu; 127 } u; 128 spinlock_t pa_lock; 129 atomic_t pa_count; 130 unsigned pa_deleted; 131 ext4_fsblk_t pa_pstart; /* phys. block */ 132 ext4_lblk_t pa_lstart; /* log. block */ 133 ext4_grpblk_t pa_len; /* len of preallocated chunk */ 134 ext4_grpblk_t pa_free; /* how many blocks are free */ 135 unsigned short pa_type; /* pa type. inode or group */ 136 union { 137 rwlock_t *inode_lock; /* locks the rbtree holding this PA */ 138 spinlock_t *lg_lock; /* locks the lg list holding this PA */ 139 } pa_node_lock; 140 struct inode *pa_inode; /* used to get the inode during group discard */ 141 }; 142 143 enum { 144 MB_INODE_PA = 0, 145 MB_GROUP_PA = 1 146 }; 147 148 struct ext4_free_extent { 149 ext4_lblk_t fe_logical; 150 ext4_grpblk_t fe_start; /* In cluster units */ 151 ext4_group_t fe_group; 152 ext4_grpblk_t fe_len; /* In cluster units */ 153 }; 154 155 /* 156 * Locality group: 157 * we try to group all related changes together 158 * so that writeback can flush/allocate them together as well 159 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC 160 * (512). We store prealloc space into the hash based on the pa_free blocks 161 * order value.ie, fls(pa_free)-1; 162 */ 163 #define PREALLOC_TB_SIZE 10 164 struct ext4_locality_group { 165 /* for allocator */ 166 /* to serialize allocates */ 167 struct mutex lg_mutex; 168 /* list of preallocations */ 169 struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; 170 spinlock_t lg_prealloc_lock; 171 }; 172 173 struct ext4_allocation_context { 174 struct inode *ac_inode; 175 struct super_block *ac_sb; 176 177 /* original request */ 178 struct ext4_free_extent ac_o_ex; 179 180 /* goal request (normalized ac_o_ex) */ 181 struct ext4_free_extent ac_g_ex; 182 183 /* the best found extent */ 184 struct ext4_free_extent ac_b_ex; 185 186 /* copy of the best found extent taken before preallocation efforts */ 187 struct ext4_free_extent ac_f_ex; 188 189 /* 190 * goal len can change in CR1.5, so save the original len. This is 191 * used while adjusting the PA window and for accounting. 192 */ 193 ext4_grpblk_t ac_orig_goal_len; 194 195 __u32 ac_groups_considered; 196 __u32 ac_flags; /* allocation hints */ 197 __u32 ac_groups_linear_remaining; 198 __u16 ac_groups_scanned; 199 __u16 ac_found; 200 __u16 ac_cX_found[EXT4_MB_NUM_CRS]; 201 __u16 ac_tail; 202 __u16 ac_buddy; 203 __u8 ac_status; 204 __u8 ac_criteria; 205 __u8 ac_2order; /* if request is to allocate 2^N blocks and 206 * N > 0, the field stores N, otherwise 0 */ 207 __u8 ac_op; /* operation, for history only */ 208 struct page *ac_bitmap_page; 209 struct page *ac_buddy_page; 210 struct ext4_prealloc_space *ac_pa; 211 struct ext4_locality_group *ac_lg; 212 }; 213 214 #define AC_STATUS_CONTINUE 1 215 #define AC_STATUS_FOUND 2 216 #define AC_STATUS_BREAK 3 217 218 struct ext4_buddy { 219 struct page *bd_buddy_page; 220 void *bd_buddy; 221 struct page *bd_bitmap_page; 222 void *bd_bitmap; 223 struct ext4_group_info *bd_info; 224 struct super_block *bd_sb; 225 __u16 bd_blkbits; 226 ext4_group_t bd_group; 227 }; 228 229 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, 230 struct ext4_free_extent *fex) 231 { 232 return ext4_group_first_block_no(sb, fex->fe_group) + 233 (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); 234 } 235 236 static inline loff_t extent_logical_end(struct ext4_sb_info *sbi, 237 struct ext4_free_extent *fex) 238 { 239 /* Use loff_t to avoid end exceeding ext4_lblk_t max. */ 240 return (loff_t)fex->fe_logical + EXT4_C2B(sbi, fex->fe_len); 241 } 242 243 static inline loff_t pa_logical_end(struct ext4_sb_info *sbi, 244 struct ext4_prealloc_space *pa) 245 { 246 /* Use loff_t to avoid end exceeding ext4_lblk_t max. */ 247 return (loff_t)pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len); 248 } 249 250 typedef int (*ext4_mballoc_query_range_fn)( 251 struct super_block *sb, 252 ext4_group_t agno, 253 ext4_grpblk_t start, 254 ext4_grpblk_t len, 255 void *priv); 256 257 int 258 ext4_mballoc_query_range( 259 struct super_block *sb, 260 ext4_group_t agno, 261 ext4_grpblk_t start, 262 ext4_grpblk_t end, 263 ext4_mballoc_query_range_fn formatter, 264 void *priv); 265 266 #endif 267