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, a...) \ 31 do { \ 32 if ((n) <= ext4_mballoc_debug) { \ 33 printk(KERN_DEBUG "(%s, %d): %s: ", \ 34 __FILE__, __LINE__, __func__); \ 35 printk(fmt, ## a); \ 36 } \ 37 } while (0) 38 #else 39 #define mb_debug(n, fmt, a...) no_printk(fmt, ## a) 40 #endif 41 42 #define EXT4_MB_HISTORY_ALLOC 1 /* allocation */ 43 #define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */ 44 45 /* 46 * How long mballoc can look for a best extent (in found extents) 47 */ 48 #define MB_DEFAULT_MAX_TO_SCAN 200 49 50 /* 51 * How long mballoc must look for a best extent 52 */ 53 #define MB_DEFAULT_MIN_TO_SCAN 10 54 55 /* 56 * with 'ext4_mb_stats' allocator will collect stats that will be 57 * shown at umount. The collecting costs though! 58 */ 59 #define MB_DEFAULT_STATS 0 60 61 /* 62 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served 63 * by the stream allocator, which purpose is to pack requests 64 * as close each to other as possible to produce smooth I/O traffic 65 * We use locality group prealloc space for stream request. 66 * We can tune the same via /proc/fs/ext4/<parition>/stream_req 67 */ 68 #define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */ 69 70 /* 71 * for which requests use 2^N search using buddies 72 */ 73 #define MB_DEFAULT_ORDER2_REQS 2 74 75 /* 76 * default group prealloc size 512 blocks 77 */ 78 #define MB_DEFAULT_GROUP_PREALLOC 512 79 80 81 struct ext4_free_data { 82 /* MUST be the first member */ 83 struct ext4_journal_cb_entry efd_jce; 84 85 /* ext4_free_data private data starts from here */ 86 87 /* this links the free block information from group_info */ 88 struct rb_node efd_node; 89 90 /* group which free block extent belongs */ 91 ext4_group_t efd_group; 92 93 /* free block extent */ 94 ext4_grpblk_t efd_start_cluster; 95 ext4_grpblk_t efd_count; 96 97 /* transaction which freed this extent */ 98 tid_t efd_tid; 99 }; 100 101 struct ext4_prealloc_space { 102 struct list_head pa_inode_list; 103 struct list_head pa_group_list; 104 union { 105 struct list_head pa_tmp_list; 106 struct rcu_head pa_rcu; 107 } u; 108 spinlock_t pa_lock; 109 atomic_t pa_count; 110 unsigned pa_deleted; 111 ext4_fsblk_t pa_pstart; /* phys. block */ 112 ext4_lblk_t pa_lstart; /* log. block */ 113 ext4_grpblk_t pa_len; /* len of preallocated chunk */ 114 ext4_grpblk_t pa_free; /* how many blocks are free */ 115 unsigned short pa_type; /* pa type. inode or group */ 116 spinlock_t *pa_obj_lock; 117 struct inode *pa_inode; /* hack, for history only */ 118 }; 119 120 enum { 121 MB_INODE_PA = 0, 122 MB_GROUP_PA = 1 123 }; 124 125 struct ext4_free_extent { 126 ext4_lblk_t fe_logical; 127 ext4_grpblk_t fe_start; /* In cluster units */ 128 ext4_group_t fe_group; 129 ext4_grpblk_t fe_len; /* In cluster units */ 130 }; 131 132 /* 133 * Locality group: 134 * we try to group all related changes together 135 * so that writeback can flush/allocate them together as well 136 * Size of lg_prealloc_list hash is determined by MB_DEFAULT_GROUP_PREALLOC 137 * (512). We store prealloc space into the hash based on the pa_free blocks 138 * order value.ie, fls(pa_free)-1; 139 */ 140 #define PREALLOC_TB_SIZE 10 141 struct ext4_locality_group { 142 /* for allocator */ 143 /* to serialize allocates */ 144 struct mutex lg_mutex; 145 /* list of preallocations */ 146 struct list_head lg_prealloc_list[PREALLOC_TB_SIZE]; 147 spinlock_t lg_prealloc_lock; 148 }; 149 150 struct ext4_allocation_context { 151 struct inode *ac_inode; 152 struct super_block *ac_sb; 153 154 /* original request */ 155 struct ext4_free_extent ac_o_ex; 156 157 /* goal request (normalized ac_o_ex) */ 158 struct ext4_free_extent ac_g_ex; 159 160 /* the best found extent */ 161 struct ext4_free_extent ac_b_ex; 162 163 /* copy of the best found extent taken before preallocation efforts */ 164 struct ext4_free_extent ac_f_ex; 165 166 __u16 ac_groups_scanned; 167 __u16 ac_found; 168 __u16 ac_tail; 169 __u16 ac_buddy; 170 __u16 ac_flags; /* allocation hints */ 171 __u8 ac_status; 172 __u8 ac_criteria; 173 __u8 ac_2order; /* if request is to allocate 2^N blocks and 174 * N > 0, the field stores N, otherwise 0 */ 175 __u8 ac_op; /* operation, for history only */ 176 struct page *ac_bitmap_page; 177 struct page *ac_buddy_page; 178 struct ext4_prealloc_space *ac_pa; 179 struct ext4_locality_group *ac_lg; 180 }; 181 182 #define AC_STATUS_CONTINUE 1 183 #define AC_STATUS_FOUND 2 184 #define AC_STATUS_BREAK 3 185 186 struct ext4_buddy { 187 struct page *bd_buddy_page; 188 void *bd_buddy; 189 struct page *bd_bitmap_page; 190 void *bd_bitmap; 191 struct ext4_group_info *bd_info; 192 struct super_block *bd_sb; 193 __u16 bd_blkbits; 194 ext4_group_t bd_group; 195 }; 196 197 static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, 198 struct ext4_free_extent *fex) 199 { 200 return ext4_group_first_block_no(sb, fex->fe_group) + 201 (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); 202 } 203 #endif 204