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/blkdev.h> 21 #include <linux/mutex.h> 22 #include "ext4_jbd2.h" 23 #include "ext4.h" 24 25 /* 26 */ 27 #ifdef CONFIG_EXT4_DEBUG 28 extern ushort ext4_mballoc_debug; 29 30 #define mb_debug(n, fmt, ...) \ 31 do { \ 32 if ((n) <= ext4_mballoc_debug) { \ 33 printk(KERN_DEBUG "(%s, %d): %s: " fmt, \ 34 __FILE__, __LINE__, __func__, ##__VA_ARGS__); \ 35 } \ 36 } while (0) 37 #else 38 #define mb_debug(n, fmt, ...) no_printk(fmt, ##__VA_ARGS__) 39 #endif 40 41 #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ 42 #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ 43 44 /* 45 * How long mballoc can look for a best extent (in found extents) 46 */ 47 #define MB_DEFAULT_MAX_TO_SCAN 200 48 49 /* 50 * How long mballoc must look for a best extent 51 */ 52 #define MB_DEFAULT_MIN_TO_SCAN 10 53 54 /* 55 * with 'ext4_mb_stats' allocator will collect stats that will be 56 * shown at umount. The collecting costs though! 57 */ 58 #define MB_DEFAULT_STATS 0 59 60 /* 61 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served 62 * by the stream allocator, which purpose is to pack requests 63 * as close each to other as possible to produce smooth I/O traffic 64 * We use locality group prealloc space for stream request. 65 * We can tune the same via /proc/fs/ext4/<parition>/stream_req 66 */ 67 #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ 68 69 /* 70 * for which requests use 2^N search using buddies 71 */ 72 #define MB_DEFAULT_ORDER2_REQS 2 73 74 /* 75 * default group prealloc size 512 blocks 76 */ 77 #define MB_DEFAULT_GROUP_PREALLOC 512 78 79 80 struct ext4_free_data { 81 /* this links the free block information from sb_info */ 82 struct list_head efd_list; 83 84 /* this links the free block information from group_info */ 85 struct rb_node efd_node; 86 87 /* group which free block extent belongs */ 88 ext4_group_t efd_group; 89 90 /* free block extent */ 91 ext4_grpblk_t efd_start_cluster; 92 ext4_grpblk_t efd_count; 93 94 /* transaction which freed this extent */ 95 tid_t efd_tid; 96 }; 97 98 struct ext4_prealloc_space { 99 struct list_head pa_inode_list; 100 struct list_head pa_group_list; 101 union { 102 struct list_head pa_tmp_list; 103 struct rcu_head pa_rcu; 104 } u; 105 spinlock_t pa_lock; 106 atomic_t pa_count; 107 unsigned pa_deleted; 108 ext4_fsblk_t pa_pstart; /* phys. block */ 109 ext4_lblk_t pa_lstart; /* log. block */ 110 ext4_grpblk_t pa_len; /* len of preallocated chunk */ 111 ext4_grpblk_t pa_free; /* how many blocks are free */ 112 unsigned short pa_type; /* pa type. inode or group */ 113 spinlock_t *pa_obj_lock; 114 struct inode *pa_inode; /* hack, for history only */ 115 }; 116 117 enum { 118 MB_INODE_PA = 0, 119 MB_GROUP_PA = 1 120 }; 121 122 struct ext4_free_extent { 123 ext4_lblk_t fe_logical; 124 ext4_grpblk_t fe_start; /* In cluster units */ 125 ext4_group_t fe_group; 126 ext4_grpblk_t fe_len; /* In cluster units */ 127 }; 128 129 /* 130 * Locality group: 131 * we try to group all related changes together 132 * so that writeback can flush/allocate them together as well 133 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC 134 * (512). We store prealloc space into the hash based on the pa_free blocks 135 * order value.ie, fls(pa_free)-1; 136 */ 137 #define PREALLOC_TB_SIZE 10 138 struct ext4_locality_group { 139 /* for allocator */ 140 /* to serialize allocates */ 141 struct mutex lg_mutex; 142 /* list of preallocations */ 143 struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; 144 spinlock_t lg_prealloc_lock; 145 }; 146 147 struct ext4_allocation_context { 148 struct inode *ac_inode; 149 struct super_block *ac_sb; 150 151 /* original request */ 152 struct ext4_free_extent ac_o_ex; 153 154 /* goal request (normalized ac_o_ex) */ 155 struct ext4_free_extent ac_g_ex; 156 157 /* the best found extent */ 158 struct ext4_free_extent ac_b_ex; 159 160 /* copy of the best found extent taken before preallocation efforts */ 161 struct ext4_free_extent ac_f_ex; 162 163 __u16 ac_groups_scanned; 164 __u16 ac_found; 165 __u16 ac_tail; 166 __u16 ac_buddy; 167 __u16 ac_flags; /* allocation hints */ 168 __u8 ac_status; 169 __u8 ac_criteria; 170 __u8 ac_2order; /* if request is to allocate 2^N blocks and 171 * N > 0, the field stores N, otherwise 0 */ 172 __u8 ac_op; /* operation, for history only */ 173 struct page *ac_bitmap_page; 174 struct page *ac_buddy_page; 175 struct ext4_prealloc_space *ac_pa; 176 struct ext4_locality_group *ac_lg; 177 }; 178 179 #define AC_STATUS_CONTINUE 1 180 #define AC_STATUS_FOUND 2 181 #define AC_STATUS_BREAK 3 182 183 struct ext4_buddy { 184 struct page *bd_buddy_page; 185 void *bd_buddy; 186 struct page *bd_bitmap_page; 187 void *bd_bitmap; 188 struct ext4_group_info *bd_info; 189 struct super_block *bd_sb; 190 __u16 bd_blkbits; 191 ext4_group_t bd_group; 192 }; 193 194 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, 195 struct ext4_free_extent *fex) 196 { 197 return ext4_group_first_block_no(sb, fex->fe_group) + 198 (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); 199 } 200 201 typedef int (*ext4_mballoc_query_range_fn)( 202 struct super_block *sb, 203 ext4_group_t agno, 204 ext4_grpblk_t start, 205 ext4_grpblk_t len, 206 void *priv); 207 208 int 209 ext4_mballoc_query_range( 210 struct super_block *sb, 211 ext4_group_t agno, 212 ext4_grpblk_t start, 213 ext4_grpblk_t end, 214 ext4_mballoc_query_range_fn formatter, 215 void *priv); 216 217 #endif 218