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 'ext4_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/<parition>/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 * maximum length of inode prealloc list 78 */ 79 #define MB_DEFAULT_MAX_INODE_PREALLOC 512 80 81 struct ext4_free_data { 82 /* this links the free block information from sb_info */ 83 struct list_head efd_list; 84 85 /* this links the free block information from group_info */ 86 struct rb_node efd_node; 87 88 /* group which free block extent belongs */ 89 ext4_group_t efd_group; 90 91 /* free block extent */ 92 ext4_grpblk_t efd_start_cluster; 93 ext4_grpblk_t efd_count; 94 95 /* transaction which freed this extent */ 96 tid_t efd_tid; 97 }; 98 99 struct ext4_prealloc_space { 100 struct list_head pa_inode_list; 101 struct list_head pa_group_list; 102 union { 103 struct list_head pa_tmp_list; 104 struct rcu_head pa_rcu; 105 } u; 106 spinlock_t pa_lock; 107 atomic_t pa_count; 108 unsigned pa_deleted; 109 ext4_fsblk_t pa_pstart; /* phys. block */ 110 ext4_lblk_t pa_lstart; /* log. block */ 111 ext4_grpblk_t pa_len; /* len of preallocated chunk */ 112 ext4_grpblk_t pa_free; /* how many blocks are free */ 113 unsigned short pa_type; /* pa type. inode or group */ 114 spinlock_t *pa_obj_lock; 115 struct inode *pa_inode; /* hack, for history only */ 116 }; 117 118 enum { 119 MB_INODE_PA = 0, 120 MB_GROUP_PA = 1 121 }; 122 123 struct ext4_free_extent { 124 ext4_lblk_t fe_logical; 125 ext4_grpblk_t fe_start; /* In cluster units */ 126 ext4_group_t fe_group; 127 ext4_grpblk_t fe_len; /* In cluster units */ 128 }; 129 130 /* 131 * Locality group: 132 * we try to group all related changes together 133 * so that writeback can flush/allocate them together as well 134 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC 135 * (512). We store prealloc space into the hash based on the pa_free blocks 136 * order value.ie, fls(pa_free)-1; 137 */ 138 #define PREALLOC_TB_SIZE 10 139 struct ext4_locality_group { 140 /* for allocator */ 141 /* to serialize allocates */ 142 struct mutex lg_mutex; 143 /* list of preallocations */ 144 struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; 145 spinlock_t lg_prealloc_lock; 146 }; 147 148 struct ext4_allocation_context { 149 struct inode *ac_inode; 150 struct super_block *ac_sb; 151 152 /* original request */ 153 struct ext4_free_extent ac_o_ex; 154 155 /* goal request (normalized ac_o_ex) */ 156 struct ext4_free_extent ac_g_ex; 157 158 /* the best found extent */ 159 struct ext4_free_extent ac_b_ex; 160 161 /* copy of the best found extent taken before preallocation efforts */ 162 struct ext4_free_extent ac_f_ex; 163 164 __u16 ac_groups_scanned; 165 __u16 ac_found; 166 __u16 ac_tail; 167 __u16 ac_buddy; 168 __u16 ac_flags; /* allocation hints */ 169 __u8 ac_status; 170 __u8 ac_criteria; 171 __u8 ac_2order; /* if request is to allocate 2^N blocks and 172 * N > 0, the field stores N, otherwise 0 */ 173 __u8 ac_op; /* operation, for history only */ 174 struct page *ac_bitmap_page; 175 struct page *ac_buddy_page; 176 struct ext4_prealloc_space *ac_pa; 177 struct ext4_locality_group *ac_lg; 178 }; 179 180 #define AC_STATUS_CONTINUE 1 181 #define AC_STATUS_FOUND 2 182 #define AC_STATUS_BREAK 3 183 184 struct ext4_buddy { 185 struct page *bd_buddy_page; 186 void *bd_buddy; 187 struct page *bd_bitmap_page; 188 void *bd_bitmap; 189 struct ext4_group_info *bd_info; 190 struct super_block *bd_sb; 191 __u16 bd_blkbits; 192 ext4_group_t bd_group; 193 }; 194 195 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, 196 struct ext4_free_extent *fex) 197 { 198 return ext4_group_first_block_no(sb, fex->fe_group) + 199 (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); 200 } 201 202 typedef int (*ext4_mballoc_query_range_fn)( 203 struct super_block *sb, 204 ext4_group_t agno, 205 ext4_grpblk_t start, 206 ext4_grpblk_t len, 207 void *priv); 208 209 int 210 ext4_mballoc_query_range( 211 struct super_block *sb, 212 ext4_group_t agno, 213 ext4_grpblk_t start, 214 ext4_grpblk_t end, 215 ext4_mballoc_query_range_fn formatter, 216 void *priv); 217 218 #endif 219