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