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 /* MUST be the first member */ 82 struct ext4_journal_cb_entry efd_jce; 83 84 /* ext4_free_data private data starts from here */ 85 86 /* this links the free block information from group_info */ 87 struct rb_node efd_node; 88 89 /* group which free block extent belongs */ 90 ext4_group_t efd_group; 91 92 /* free block extent */ 93 ext4_grpblk_t efd_start_cluster; 94 ext4_grpblk_t efd_count; 95 96 /* transaction which freed this extent */ 97 tid_t efd_tid; 98 }; 99 100 struct ext4_prealloc_space { 101 struct list_head pa_inode_list; 102 struct list_head pa_group_list; 103 union { 104 struct list_head pa_tmp_list; 105 struct rcu_head pa_rcu; 106 } u; 107 spinlock_t pa_lock; 108 atomic_t pa_count; 109 unsigned pa_deleted; 110 ext4_fsblk_t pa_pstart; /* phys. block */ 111 ext4_lblk_t pa_lstart; /* log. block */ 112 ext4_grpblk_t pa_len; /* len of preallocated chunk */ 113 ext4_grpblk_t pa_free; /* how many blocks are free */ 114 unsigned short pa_type; /* pa type. inode or group */ 115 spinlock_t *pa_obj_lock; 116 struct inode *pa_inode; /* hack, for history only */ 117 }; 118 119 enum { 120 MB_INODE_PA = 0, 121 MB_GROUP_PA = 1 122 }; 123 124 struct ext4_free_extent { 125 ext4_lblk_t fe_logical; 126 ext4_grpblk_t fe_start; /* In cluster units */ 127 ext4_group_t fe_group; 128 ext4_grpblk_t fe_len; /* In cluster units */ 129 }; 130 131 /* 132 * Locality group: 133 * we try to group all related changes together 134 * so that writeback can flush/allocate them together as well 135 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC 136 * (512). We store prealloc space into the hash based on the pa_free blocks 137 * order value.ie, fls(pa_free)-1; 138 */ 139 #define PREALLOC_TB_SIZE 10 140 struct ext4_locality_group { 141 /* for allocator */ 142 /* to serialize allocates */ 143 struct mutex lg_mutex; 144 /* list of preallocations */ 145 struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; 146 spinlock_t lg_prealloc_lock; 147 }; 148 149 struct ext4_allocation_context { 150 struct inode *ac_inode; 151 struct super_block *ac_sb; 152 153 /* original request */ 154 struct ext4_free_extent ac_o_ex; 155 156 /* goal request (normalized ac_o_ex) */ 157 struct ext4_free_extent ac_g_ex; 158 159 /* the best found extent */ 160 struct ext4_free_extent ac_b_ex; 161 162 /* copy of the best found extent taken before preallocation efforts */ 163 struct ext4_free_extent ac_f_ex; 164 165 __u16 ac_groups_scanned; 166 __u16 ac_found; 167 __u16 ac_tail; 168 __u16 ac_buddy; 169 __u16 ac_flags; /* allocation hints */ 170 __u8 ac_status; 171 __u8 ac_criteria; 172 __u8 ac_2order; /* if request is to allocate 2^N blocks and 173 * N > 0, the field stores N, otherwise 0 */ 174 __u8 ac_op; /* operation, for history only */ 175 struct page *ac_bitmap_page; 176 struct page *ac_buddy_page; 177 struct ext4_prealloc_space *ac_pa; 178 struct ext4_locality_group *ac_lg; 179 }; 180 181 #define AC_STATUS_CONTINUE 1 182 #define AC_STATUS_FOUND 2 183 #define AC_STATUS_BREAK 3 184 185 struct ext4_buddy { 186 struct page *bd_buddy_page; 187 void *bd_buddy; 188 struct page *bd_bitmap_page; 189 void *bd_bitmap; 190 struct ext4_group_info *bd_info; 191 struct super_block *bd_sb; 192 __u16 bd_blkbits; 193 ext4_group_t bd_group; 194 }; 195 196 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, 197 struct ext4_free_extent *fex) 198 { 199 return ext4_group_first_block_no(sb, fex->fe_group) + 200 (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); 201 } 202 #endif 203