Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/ext3/balloc.c |
| 3 | * |
| 4 | * Copyright (C) 1992, 1993, 1994, 1995 |
| 5 | * Remy Card (card@masi.ibp.fr) |
| 6 | * Laboratoire MASI - Institut Blaise Pascal |
| 7 | * Universite Pierre et Marie Curie (Paris VI) |
| 8 | * |
| 9 | * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993 |
| 10 | * Big-endian to little-endian byte-swapping/bitmaps by |
| 11 | * David S. Miller (davem@caip.rutgers.edu), 1995 |
| 12 | */ |
| 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/time.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 15 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/fs.h> |
| 17 | #include <linux/jbd.h> |
| 18 | #include <linux/ext3_fs.h> |
| 19 | #include <linux/ext3_jbd.h> |
| 20 | #include <linux/quotaops.h> |
| 21 | #include <linux/buffer_head.h> |
| 22 | |
| 23 | /* |
| 24 | * balloc.c contains the blocks allocation and deallocation routines |
| 25 | */ |
| 26 | |
| 27 | /* |
| 28 | * The free blocks are managed by bitmaps. A file system contains several |
| 29 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap |
| 30 | * block for inodes, N blocks for the inode table and data blocks. |
| 31 | * |
| 32 | * The file system contains group descriptors which are located after the |
| 33 | * super block. Each descriptor contains the number of the bitmap block and |
| 34 | * the free blocks count in the block. The descriptors are loaded in memory |
Aneesh Kumar K.V | e627432 | 2007-02-20 13:57:58 -0800 | [diff] [blame] | 35 | * when a file system is mounted (see ext3_fill_super). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | */ |
| 37 | |
| 38 | |
| 39 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) |
| 40 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 41 | /** |
| 42 | * ext3_get_group_desc() -- load group descriptor from disk |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 43 | * @sb: super block |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 44 | * @block_group: given block group |
| 45 | * @bh: pointer to the buffer head to store the block |
| 46 | * group descriptor |
| 47 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, |
| 49 | unsigned int block_group, |
| 50 | struct buffer_head ** bh) |
| 51 | { |
| 52 | unsigned long group_desc; |
| 53 | unsigned long offset; |
| 54 | struct ext3_group_desc * desc; |
| 55 | struct ext3_sb_info *sbi = EXT3_SB(sb); |
| 56 | |
| 57 | if (block_group >= sbi->s_groups_count) { |
| 58 | ext3_error (sb, "ext3_get_group_desc", |
| 59 | "block_group >= groups_count - " |
| 60 | "block_group = %d, groups_count = %lu", |
| 61 | block_group, sbi->s_groups_count); |
| 62 | |
| 63 | return NULL; |
| 64 | } |
| 65 | smp_rmb(); |
| 66 | |
| 67 | group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb); |
| 68 | offset = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1); |
| 69 | if (!sbi->s_group_desc[group_desc]) { |
| 70 | ext3_error (sb, "ext3_get_group_desc", |
| 71 | "Group descriptor not loaded - " |
| 72 | "block_group = %d, group_desc = %lu, desc = %lu", |
| 73 | block_group, group_desc, offset); |
| 74 | return NULL; |
| 75 | } |
| 76 | |
| 77 | desc = (struct ext3_group_desc *) sbi->s_group_desc[group_desc]->b_data; |
| 78 | if (bh) |
| 79 | *bh = sbi->s_group_desc[group_desc]; |
| 80 | return desc + offset; |
| 81 | } |
| 82 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 83 | /** |
| 84 | * read_block_bitmap() |
| 85 | * @sb: super block |
| 86 | * @block_group: given block group |
| 87 | * |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 88 | * Read the bitmap for a given block_group, reading into the specified |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | * slot in the superblock's bitmap cache. |
| 90 | * |
| 91 | * Return buffer_head on success or NULL in case of failure. |
| 92 | */ |
| 93 | static struct buffer_head * |
| 94 | read_block_bitmap(struct super_block *sb, unsigned int block_group) |
| 95 | { |
| 96 | struct ext3_group_desc * desc; |
| 97 | struct buffer_head * bh = NULL; |
| 98 | |
| 99 | desc = ext3_get_group_desc (sb, block_group, NULL); |
| 100 | if (!desc) |
| 101 | goto error_out; |
| 102 | bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); |
| 103 | if (!bh) |
| 104 | ext3_error (sb, "read_block_bitmap", |
| 105 | "Cannot read block bitmap - " |
| 106 | "block_group = %d, block_bitmap = %u", |
| 107 | block_group, le32_to_cpu(desc->bg_block_bitmap)); |
| 108 | error_out: |
| 109 | return bh; |
| 110 | } |
| 111 | /* |
| 112 | * The reservation window structure operations |
| 113 | * -------------------------------------------- |
| 114 | * Operations include: |
| 115 | * dump, find, add, remove, is_empty, find_next_reservable_window, etc. |
| 116 | * |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 117 | * We use a red-black tree to represent per-filesystem reservation |
| 118 | * windows. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | * |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 120 | */ |
| 121 | |
| 122 | /** |
| 123 | * __rsv_window_dump() -- Dump the filesystem block allocation reservation map |
| 124 | * @rb_root: root of per-filesystem reservation rb tree |
| 125 | * @verbose: verbose mode |
| 126 | * @fn: function which wishes to dump the reservation map |
| 127 | * |
| 128 | * If verbose is turned on, it will print the whole block reservation |
| 129 | * windows(start, end). Otherwise, it will only print out the "bad" windows, |
| 130 | * those windows that overlap with their immediate neighbors. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | */ |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 132 | #if 1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | static void __rsv_window_dump(struct rb_root *root, int verbose, |
| 134 | const char *fn) |
| 135 | { |
| 136 | struct rb_node *n; |
| 137 | struct ext3_reserve_window_node *rsv, *prev; |
| 138 | int bad; |
| 139 | |
| 140 | restart: |
| 141 | n = rb_first(root); |
| 142 | bad = 0; |
| 143 | prev = NULL; |
| 144 | |
| 145 | printk("Block Allocation Reservation Windows Map (%s):\n", fn); |
| 146 | while (n) { |
Hugh Dickins | c56d256 | 2006-12-06 20:41:27 -0800 | [diff] [blame] | 147 | rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | if (verbose) |
| 149 | printk("reservation window 0x%p " |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 150 | "start: %lu, end: %lu\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | rsv, rsv->rsv_start, rsv->rsv_end); |
| 152 | if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { |
| 153 | printk("Bad reservation %p (start >= end)\n", |
| 154 | rsv); |
| 155 | bad = 1; |
| 156 | } |
| 157 | if (prev && prev->rsv_end >= rsv->rsv_start) { |
| 158 | printk("Bad reservation %p (prev->end >= start)\n", |
| 159 | rsv); |
| 160 | bad = 1; |
| 161 | } |
| 162 | if (bad) { |
| 163 | if (!verbose) { |
| 164 | printk("Restarting reservation walk in verbose mode\n"); |
| 165 | verbose = 1; |
| 166 | goto restart; |
| 167 | } |
| 168 | } |
| 169 | n = rb_next(n); |
| 170 | prev = rsv; |
| 171 | } |
| 172 | printk("Window map complete.\n"); |
| 173 | if (bad) |
| 174 | BUG(); |
| 175 | } |
| 176 | #define rsv_window_dump(root, verbose) \ |
| 177 | __rsv_window_dump((root), (verbose), __FUNCTION__) |
| 178 | #else |
| 179 | #define rsv_window_dump(root, verbose) do {} while (0) |
| 180 | #endif |
| 181 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 182 | /** |
| 183 | * goal_in_my_reservation() |
| 184 | * @rsv: inode's reservation window |
| 185 | * @grp_goal: given goal block relative to the allocation block group |
| 186 | * @group: the current allocation block group |
| 187 | * @sb: filesystem super block |
| 188 | * |
| 189 | * Test if the given goal block (group relative) is within the file's |
| 190 | * own block reservation window range. |
| 191 | * |
| 192 | * If the reservation window is outside the goal allocation group, return 0; |
| 193 | * grp_goal (given goal block) could be -1, which means no specific |
| 194 | * goal block. In this case, always return 1. |
| 195 | * If the goal block is within the reservation window, return 1; |
| 196 | * otherwise, return 0; |
| 197 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | static int |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 199 | goal_in_my_reservation(struct ext3_reserve_window *rsv, ext3_grpblk_t grp_goal, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | unsigned int group, struct super_block * sb) |
| 201 | { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 202 | ext3_fsblk_t group_first_block, group_last_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 204 | group_first_block = ext3_group_first_block_no(sb, group); |
Eric Sandeen | 32c2d2b | 2006-09-27 01:49:36 -0700 | [diff] [blame] | 205 | group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | |
| 207 | if ((rsv->_rsv_start > group_last_block) || |
| 208 | (rsv->_rsv_end < group_first_block)) |
| 209 | return 0; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 210 | if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start) |
| 211 | || (grp_goal + group_first_block > rsv->_rsv_end))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | return 0; |
| 213 | return 1; |
| 214 | } |
| 215 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 216 | /** |
| 217 | * search_reserve_window() |
| 218 | * @rb_root: root of reservation tree |
| 219 | * @goal: target allocation block |
| 220 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | * Find the reserved window which includes the goal, or the previous one |
| 222 | * if the goal is not in any window. |
| 223 | * Returns NULL if there are no windows or if all windows start after the goal. |
| 224 | */ |
| 225 | static struct ext3_reserve_window_node * |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 226 | search_reserve_window(struct rb_root *root, ext3_fsblk_t goal) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | { |
| 228 | struct rb_node *n = root->rb_node; |
| 229 | struct ext3_reserve_window_node *rsv; |
| 230 | |
| 231 | if (!n) |
| 232 | return NULL; |
| 233 | |
| 234 | do { |
| 235 | rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); |
| 236 | |
| 237 | if (goal < rsv->rsv_start) |
| 238 | n = n->rb_left; |
| 239 | else if (goal > rsv->rsv_end) |
| 240 | n = n->rb_right; |
| 241 | else |
| 242 | return rsv; |
| 243 | } while (n); |
| 244 | /* |
| 245 | * We've fallen off the end of the tree: the goal wasn't inside |
| 246 | * any particular node. OK, the previous node must be to one |
| 247 | * side of the interval containing the goal. If it's the RHS, |
| 248 | * we need to back up one. |
| 249 | */ |
| 250 | if (rsv->rsv_start > goal) { |
| 251 | n = rb_prev(&rsv->rsv_node); |
| 252 | rsv = rb_entry(n, struct ext3_reserve_window_node, rsv_node); |
| 253 | } |
| 254 | return rsv; |
| 255 | } |
| 256 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 257 | /** |
| 258 | * ext3_rsv_window_add() -- Insert a window to the block reservation rb tree. |
| 259 | * @sb: super block |
| 260 | * @rsv: reservation window to add |
| 261 | * |
| 262 | * Must be called with rsv_lock hold. |
| 263 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | void ext3_rsv_window_add(struct super_block *sb, |
| 265 | struct ext3_reserve_window_node *rsv) |
| 266 | { |
| 267 | struct rb_root *root = &EXT3_SB(sb)->s_rsv_window_root; |
| 268 | struct rb_node *node = &rsv->rsv_node; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 269 | ext3_fsblk_t start = rsv->rsv_start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 270 | |
| 271 | struct rb_node ** p = &root->rb_node; |
| 272 | struct rb_node * parent = NULL; |
| 273 | struct ext3_reserve_window_node *this; |
| 274 | |
| 275 | while (*p) |
| 276 | { |
| 277 | parent = *p; |
| 278 | this = rb_entry(parent, struct ext3_reserve_window_node, rsv_node); |
| 279 | |
| 280 | if (start < this->rsv_start) |
| 281 | p = &(*p)->rb_left; |
| 282 | else if (start > this->rsv_end) |
| 283 | p = &(*p)->rb_right; |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 284 | else { |
| 285 | rsv_window_dump(root, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | BUG(); |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 287 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | } |
| 289 | |
| 290 | rb_link_node(node, parent, p); |
| 291 | rb_insert_color(node, root); |
| 292 | } |
| 293 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 294 | /** |
| 295 | * ext3_rsv_window_remove() -- unlink a window from the reservation rb tree |
| 296 | * @sb: super block |
| 297 | * @rsv: reservation window to remove |
| 298 | * |
| 299 | * Mark the block reservation window as not allocated, and unlink it |
| 300 | * from the filesystem reservation window rb tree. Must be called with |
| 301 | * rsv_lock hold. |
| 302 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | static void rsv_window_remove(struct super_block *sb, |
| 304 | struct ext3_reserve_window_node *rsv) |
| 305 | { |
| 306 | rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; |
| 307 | rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; |
| 308 | rsv->rsv_alloc_hit = 0; |
| 309 | rb_erase(&rsv->rsv_node, &EXT3_SB(sb)->s_rsv_window_root); |
| 310 | } |
| 311 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 312 | /* |
| 313 | * rsv_is_empty() -- Check if the reservation window is allocated. |
| 314 | * @rsv: given reservation window to check |
| 315 | * |
| 316 | * returns 1 if the end block is EXT3_RESERVE_WINDOW_NOT_ALLOCATED. |
| 317 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | static inline int rsv_is_empty(struct ext3_reserve_window *rsv) |
| 319 | { |
| 320 | /* a valid reservation end block could not be 0 */ |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 321 | return rsv->_rsv_end == EXT3_RESERVE_WINDOW_NOT_ALLOCATED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | } |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 323 | |
| 324 | /** |
| 325 | * ext3_init_block_alloc_info() |
| 326 | * @inode: file inode structure |
| 327 | * |
| 328 | * Allocate and initialize the reservation window structure, and |
| 329 | * link the window to the ext3 inode structure at last |
| 330 | * |
| 331 | * The reservation window structure is only dynamically allocated |
| 332 | * and linked to ext3 inode the first time the open file |
| 333 | * needs a new block. So, before every ext3_new_block(s) call, for |
| 334 | * regular files, we should check whether the reservation window |
| 335 | * structure exists or not. In the latter case, this function is called. |
| 336 | * Fail to do so will result in block reservation being turned off for that |
| 337 | * open file. |
| 338 | * |
| 339 | * This function is called from ext3_get_blocks_handle(), also called |
| 340 | * when setting the reservation window size through ioctl before the file |
| 341 | * is open for write (needs block allocation). |
| 342 | * |
| 343 | * Needs truncate_mutex protection prior to call this function. |
| 344 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | void ext3_init_block_alloc_info(struct inode *inode) |
| 346 | { |
| 347 | struct ext3_inode_info *ei = EXT3_I(inode); |
| 348 | struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info; |
| 349 | struct super_block *sb = inode->i_sb; |
| 350 | |
| 351 | block_i = kmalloc(sizeof(*block_i), GFP_NOFS); |
| 352 | if (block_i) { |
| 353 | struct ext3_reserve_window_node *rsv = &block_i->rsv_window_node; |
| 354 | |
| 355 | rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; |
| 356 | rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED; |
| 357 | |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 358 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | * if filesystem is mounted with NORESERVATION, the goal |
| 360 | * reservation window size is set to zero to indicate |
| 361 | * block reservation is off |
| 362 | */ |
| 363 | if (!test_opt(sb, RESERVATION)) |
| 364 | rsv->rsv_goal_size = 0; |
| 365 | else |
| 366 | rsv->rsv_goal_size = EXT3_DEFAULT_RESERVE_BLOCKS; |
| 367 | rsv->rsv_alloc_hit = 0; |
| 368 | block_i->last_alloc_logical_block = 0; |
| 369 | block_i->last_alloc_physical_block = 0; |
| 370 | } |
| 371 | ei->i_block_alloc_info = block_i; |
| 372 | } |
| 373 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 374 | /** |
| 375 | * ext3_discard_reservation() |
| 376 | * @inode: inode |
| 377 | * |
| 378 | * Discard(free) block reservation window on last file close, or truncate |
| 379 | * or at last iput(). |
| 380 | * |
| 381 | * It is being called in three cases: |
| 382 | * ext3_release_file(): last writer close the file |
| 383 | * ext3_clear_inode(): last iput(), when nobody link to this file. |
| 384 | * ext3_truncate(): when the block indirect map is about to change. |
| 385 | * |
| 386 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | void ext3_discard_reservation(struct inode *inode) |
| 388 | { |
| 389 | struct ext3_inode_info *ei = EXT3_I(inode); |
| 390 | struct ext3_block_alloc_info *block_i = ei->i_block_alloc_info; |
| 391 | struct ext3_reserve_window_node *rsv; |
| 392 | spinlock_t *rsv_lock = &EXT3_SB(inode->i_sb)->s_rsv_window_lock; |
| 393 | |
| 394 | if (!block_i) |
| 395 | return; |
| 396 | |
| 397 | rsv = &block_i->rsv_window_node; |
| 398 | if (!rsv_is_empty(&rsv->rsv_window)) { |
| 399 | spin_lock(rsv_lock); |
| 400 | if (!rsv_is_empty(&rsv->rsv_window)) |
| 401 | rsv_window_remove(inode->i_sb, rsv); |
| 402 | spin_unlock(rsv_lock); |
| 403 | } |
| 404 | } |
| 405 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 406 | /** |
| 407 | * ext3_free_blocks_sb() -- Free given blocks and update quota |
| 408 | * @handle: handle to this transaction |
| 409 | * @sb: super block |
| 410 | * @block: start physcial block to free |
| 411 | * @count: number of blocks to free |
| 412 | * @pdquot_freed_blocks: pointer to quota |
| 413 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | void ext3_free_blocks_sb(handle_t *handle, struct super_block *sb, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 415 | ext3_fsblk_t block, unsigned long count, |
| 416 | unsigned long *pdquot_freed_blocks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | { |
| 418 | struct buffer_head *bitmap_bh = NULL; |
| 419 | struct buffer_head *gd_bh; |
| 420 | unsigned long block_group; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 421 | ext3_grpblk_t bit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 422 | unsigned long i; |
| 423 | unsigned long overflow; |
| 424 | struct ext3_group_desc * desc; |
| 425 | struct ext3_super_block * es; |
| 426 | struct ext3_sb_info *sbi; |
| 427 | int err = 0, ret; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 428 | ext3_grpblk_t group_freed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
| 430 | *pdquot_freed_blocks = 0; |
| 431 | sbi = EXT3_SB(sb); |
| 432 | es = sbi->s_es; |
| 433 | if (block < le32_to_cpu(es->s_first_data_block) || |
| 434 | block + count < block || |
| 435 | block + count > le32_to_cpu(es->s_blocks_count)) { |
| 436 | ext3_error (sb, "ext3_free_blocks", |
| 437 | "Freeing blocks not in datazone - " |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 438 | "block = "E3FSBLK", count = %lu", block, count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | goto error_return; |
| 440 | } |
| 441 | |
| 442 | ext3_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); |
| 443 | |
| 444 | do_more: |
| 445 | overflow = 0; |
| 446 | block_group = (block - le32_to_cpu(es->s_first_data_block)) / |
| 447 | EXT3_BLOCKS_PER_GROUP(sb); |
| 448 | bit = (block - le32_to_cpu(es->s_first_data_block)) % |
| 449 | EXT3_BLOCKS_PER_GROUP(sb); |
| 450 | /* |
| 451 | * Check to see if we are freeing blocks across a group |
| 452 | * boundary. |
| 453 | */ |
| 454 | if (bit + count > EXT3_BLOCKS_PER_GROUP(sb)) { |
| 455 | overflow = bit + count - EXT3_BLOCKS_PER_GROUP(sb); |
| 456 | count -= overflow; |
| 457 | } |
| 458 | brelse(bitmap_bh); |
| 459 | bitmap_bh = read_block_bitmap(sb, block_group); |
| 460 | if (!bitmap_bh) |
| 461 | goto error_return; |
| 462 | desc = ext3_get_group_desc (sb, block_group, &gd_bh); |
| 463 | if (!desc) |
| 464 | goto error_return; |
| 465 | |
| 466 | if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) || |
| 467 | in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) || |
| 468 | in_range (block, le32_to_cpu(desc->bg_inode_table), |
| 469 | sbi->s_itb_per_group) || |
| 470 | in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), |
| 471 | sbi->s_itb_per_group)) |
| 472 | ext3_error (sb, "ext3_free_blocks", |
| 473 | "Freeing blocks in system zones - " |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 474 | "Block = "E3FSBLK", count = %lu", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | block, count); |
| 476 | |
| 477 | /* |
| 478 | * We are about to start releasing blocks in the bitmap, |
| 479 | * so we need undo access. |
| 480 | */ |
| 481 | /* @@@ check errors */ |
| 482 | BUFFER_TRACE(bitmap_bh, "getting undo access"); |
| 483 | err = ext3_journal_get_undo_access(handle, bitmap_bh); |
| 484 | if (err) |
| 485 | goto error_return; |
| 486 | |
| 487 | /* |
| 488 | * We are about to modify some metadata. Call the journal APIs |
| 489 | * to unshare ->b_data if a currently-committing transaction is |
| 490 | * using it |
| 491 | */ |
| 492 | BUFFER_TRACE(gd_bh, "get_write_access"); |
| 493 | err = ext3_journal_get_write_access(handle, gd_bh); |
| 494 | if (err) |
| 495 | goto error_return; |
| 496 | |
| 497 | jbd_lock_bh_state(bitmap_bh); |
| 498 | |
| 499 | for (i = 0, group_freed = 0; i < count; i++) { |
| 500 | /* |
| 501 | * An HJ special. This is expensive... |
| 502 | */ |
| 503 | #ifdef CONFIG_JBD_DEBUG |
| 504 | jbd_unlock_bh_state(bitmap_bh); |
| 505 | { |
| 506 | struct buffer_head *debug_bh; |
| 507 | debug_bh = sb_find_get_block(sb, block + i); |
| 508 | if (debug_bh) { |
| 509 | BUFFER_TRACE(debug_bh, "Deleted!"); |
| 510 | if (!bh2jh(bitmap_bh)->b_committed_data) |
| 511 | BUFFER_TRACE(debug_bh, |
| 512 | "No commited data in bitmap"); |
| 513 | BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap"); |
| 514 | __brelse(debug_bh); |
| 515 | } |
| 516 | } |
| 517 | jbd_lock_bh_state(bitmap_bh); |
| 518 | #endif |
| 519 | if (need_resched()) { |
| 520 | jbd_unlock_bh_state(bitmap_bh); |
| 521 | cond_resched(); |
| 522 | jbd_lock_bh_state(bitmap_bh); |
| 523 | } |
| 524 | /* @@@ This prevents newly-allocated data from being |
| 525 | * freed and then reallocated within the same |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 526 | * transaction. |
| 527 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | * Ideally we would want to allow that to happen, but to |
| 529 | * do so requires making journal_forget() capable of |
| 530 | * revoking the queued write of a data block, which |
| 531 | * implies blocking on the journal lock. *forget() |
| 532 | * cannot block due to truncate races. |
| 533 | * |
| 534 | * Eventually we can fix this by making journal_forget() |
| 535 | * return a status indicating whether or not it was able |
| 536 | * to revoke the buffer. On successful revoke, it is |
| 537 | * safe not to set the allocation bit in the committed |
| 538 | * bitmap, because we know that there is no outstanding |
| 539 | * activity on the buffer any more and so it is safe to |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 540 | * reallocate it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | */ |
| 542 | BUFFER_TRACE(bitmap_bh, "set in b_committed_data"); |
| 543 | J_ASSERT_BH(bitmap_bh, |
| 544 | bh2jh(bitmap_bh)->b_committed_data != NULL); |
| 545 | ext3_set_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i, |
| 546 | bh2jh(bitmap_bh)->b_committed_data); |
| 547 | |
| 548 | /* |
| 549 | * We clear the bit in the bitmap after setting the committed |
| 550 | * data bit, because this is the reverse order to that which |
| 551 | * the allocator uses. |
| 552 | */ |
| 553 | BUFFER_TRACE(bitmap_bh, "clear bit"); |
| 554 | if (!ext3_clear_bit_atomic(sb_bgl_lock(sbi, block_group), |
| 555 | bit + i, bitmap_bh->b_data)) { |
| 556 | jbd_unlock_bh_state(bitmap_bh); |
| 557 | ext3_error(sb, __FUNCTION__, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 558 | "bit already cleared for block "E3FSBLK, |
| 559 | block + i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 560 | jbd_lock_bh_state(bitmap_bh); |
| 561 | BUFFER_TRACE(bitmap_bh, "bit already cleared"); |
| 562 | } else { |
| 563 | group_freed++; |
| 564 | } |
| 565 | } |
| 566 | jbd_unlock_bh_state(bitmap_bh); |
| 567 | |
| 568 | spin_lock(sb_bgl_lock(sbi, block_group)); |
| 569 | desc->bg_free_blocks_count = |
| 570 | cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) + |
| 571 | group_freed); |
| 572 | spin_unlock(sb_bgl_lock(sbi, block_group)); |
Peter Zijlstra | aa0dff2 | 2007-10-16 23:25:42 -0700 | [diff] [blame] | 573 | percpu_counter_add(&sbi->s_freeblocks_counter, count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | |
| 575 | /* We dirtied the bitmap block */ |
| 576 | BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); |
| 577 | err = ext3_journal_dirty_metadata(handle, bitmap_bh); |
| 578 | |
| 579 | /* And the group descriptor block */ |
| 580 | BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); |
| 581 | ret = ext3_journal_dirty_metadata(handle, gd_bh); |
| 582 | if (!err) err = ret; |
| 583 | *pdquot_freed_blocks += group_freed; |
| 584 | |
| 585 | if (overflow && !err) { |
| 586 | block += count; |
| 587 | count = overflow; |
| 588 | goto do_more; |
| 589 | } |
| 590 | sb->s_dirt = 1; |
| 591 | error_return: |
| 592 | brelse(bitmap_bh); |
| 593 | ext3_std_error(sb, err); |
| 594 | return; |
| 595 | } |
| 596 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 597 | /** |
| 598 | * ext3_free_blocks() -- Free given blocks and update quota |
| 599 | * @handle: handle for this transaction |
| 600 | * @inode: inode |
| 601 | * @block: start physical block to free |
| 602 | * @count: number of blocks to count |
| 603 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | void ext3_free_blocks(handle_t *handle, struct inode *inode, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 605 | ext3_fsblk_t block, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | { |
| 607 | struct super_block * sb; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 608 | unsigned long dquot_freed_blocks; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | |
| 610 | sb = inode->i_sb; |
| 611 | if (!sb) { |
| 612 | printk ("ext3_free_blocks: nonexistent device"); |
| 613 | return; |
| 614 | } |
| 615 | ext3_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks); |
| 616 | if (dquot_freed_blocks) |
| 617 | DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); |
| 618 | return; |
| 619 | } |
| 620 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 621 | /** |
| 622 | * ext3_test_allocatable() |
| 623 | * @nr: given allocation block group |
| 624 | * @bh: bufferhead contains the bitmap of the given block group |
| 625 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | * For ext3 allocations, we must not reuse any blocks which are |
| 627 | * allocated in the bitmap buffer's "last committed data" copy. This |
| 628 | * prevents deletes from freeing up the page for reuse until we have |
| 629 | * committed the delete transaction. |
| 630 | * |
| 631 | * If we didn't do this, then deleting something and reallocating it as |
| 632 | * data would allow the old block to be overwritten before the |
| 633 | * transaction committed (because we force data to disk before commit). |
| 634 | * This would lead to corruption if we crashed between overwriting the |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 635 | * data and committing the delete. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | * |
| 637 | * @@@ We may want to make this allocation behaviour conditional on |
| 638 | * data-writes at some point, and disable it for metadata allocations or |
| 639 | * sync-data inodes. |
| 640 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 641 | static int ext3_test_allocatable(ext3_grpblk_t nr, struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | { |
| 643 | int ret; |
| 644 | struct journal_head *jh = bh2jh(bh); |
| 645 | |
| 646 | if (ext3_test_bit(nr, bh->b_data)) |
| 647 | return 0; |
| 648 | |
| 649 | jbd_lock_bh_state(bh); |
| 650 | if (!jh->b_committed_data) |
| 651 | ret = 1; |
| 652 | else |
| 653 | ret = !ext3_test_bit(nr, jh->b_committed_data); |
| 654 | jbd_unlock_bh_state(bh); |
| 655 | return ret; |
| 656 | } |
| 657 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 658 | /** |
| 659 | * bitmap_search_next_usable_block() |
| 660 | * @start: the starting block (group relative) of the search |
| 661 | * @bh: bufferhead contains the block group bitmap |
| 662 | * @maxblocks: the ending block (group relative) of the reservation |
| 663 | * |
| 664 | * The bitmap search --- search forward alternately through the actual |
| 665 | * bitmap on disk and the last-committed copy in journal, until we find a |
| 666 | * bit free in both bitmaps. |
| 667 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 668 | static ext3_grpblk_t |
| 669 | bitmap_search_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, |
| 670 | ext3_grpblk_t maxblocks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 672 | ext3_grpblk_t next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | struct journal_head *jh = bh2jh(bh); |
| 674 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | while (start < maxblocks) { |
| 676 | next = ext3_find_next_zero_bit(bh->b_data, maxblocks, start); |
| 677 | if (next >= maxblocks) |
| 678 | return -1; |
| 679 | if (ext3_test_allocatable(next, bh)) |
| 680 | return next; |
| 681 | jbd_lock_bh_state(bh); |
| 682 | if (jh->b_committed_data) |
| 683 | start = ext3_find_next_zero_bit(jh->b_committed_data, |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 684 | maxblocks, next); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 685 | jbd_unlock_bh_state(bh); |
| 686 | } |
| 687 | return -1; |
| 688 | } |
| 689 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 690 | /** |
| 691 | * find_next_usable_block() |
| 692 | * @start: the starting block (group relative) to find next |
| 693 | * allocatable block in bitmap. |
| 694 | * @bh: bufferhead contains the block group bitmap |
| 695 | * @maxblocks: the ending block (group relative) for the search |
| 696 | * |
| 697 | * Find an allocatable block in a bitmap. We honor both the bitmap and |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | * its last-committed copy (if that exists), and perform the "most |
| 699 | * appropriate allocation" algorithm of looking for a free block near |
| 700 | * the initial goal; then for a free byte somewhere in the bitmap; then |
| 701 | * for any free bit in the bitmap. |
| 702 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 703 | static ext3_grpblk_t |
| 704 | find_next_usable_block(ext3_grpblk_t start, struct buffer_head *bh, |
| 705 | ext3_grpblk_t maxblocks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 707 | ext3_grpblk_t here, next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | char *p, *r; |
| 709 | |
| 710 | if (start > 0) { |
| 711 | /* |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 712 | * The goal was occupied; search forward for a free |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | * block within the next XX blocks. |
| 714 | * |
| 715 | * end_goal is more or less random, but it has to be |
| 716 | * less than EXT3_BLOCKS_PER_GROUP. Aligning up to the |
| 717 | * next 64-bit boundary is simple.. |
| 718 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 719 | ext3_grpblk_t end_goal = (start + 63) & ~63; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | if (end_goal > maxblocks) |
| 721 | end_goal = maxblocks; |
| 722 | here = ext3_find_next_zero_bit(bh->b_data, end_goal, start); |
| 723 | if (here < end_goal && ext3_test_allocatable(here, bh)) |
| 724 | return here; |
| 725 | ext3_debug("Bit not found near goal\n"); |
| 726 | } |
| 727 | |
| 728 | here = start; |
| 729 | if (here < 0) |
| 730 | here = 0; |
| 731 | |
| 732 | p = ((char *)bh->b_data) + (here >> 3); |
Hugh Dickins | 7d1c520 | 2006-12-06 20:41:30 -0800 | [diff] [blame] | 733 | r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | next = (r - ((char *)bh->b_data)) << 3; |
| 735 | |
| 736 | if (next < maxblocks && next >= start && ext3_test_allocatable(next, bh)) |
| 737 | return next; |
| 738 | |
| 739 | /* |
| 740 | * The bitmap search --- search forward alternately through the actual |
| 741 | * bitmap and the last-committed copy until we find a bit free in |
| 742 | * both |
| 743 | */ |
| 744 | here = bitmap_search_next_usable_block(here, bh, maxblocks); |
| 745 | return here; |
| 746 | } |
| 747 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 748 | /** |
| 749 | * claim_block() |
| 750 | * @block: the free block (group relative) to allocate |
| 751 | * @bh: the bufferhead containts the block group bitmap |
| 752 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | * We think we can allocate this block in this bitmap. Try to set the bit. |
| 754 | * If that succeeds then check that nobody has allocated and then freed the |
| 755 | * block since we saw that is was not marked in b_committed_data. If it _was_ |
| 756 | * allocated and freed then clear the bit in the bitmap again and return |
| 757 | * zero (failure). |
| 758 | */ |
| 759 | static inline int |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 760 | claim_block(spinlock_t *lock, ext3_grpblk_t block, struct buffer_head *bh) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | { |
| 762 | struct journal_head *jh = bh2jh(bh); |
| 763 | int ret; |
| 764 | |
| 765 | if (ext3_set_bit_atomic(lock, block, bh->b_data)) |
| 766 | return 0; |
| 767 | jbd_lock_bh_state(bh); |
| 768 | if (jh->b_committed_data && ext3_test_bit(block,jh->b_committed_data)) { |
| 769 | ext3_clear_bit_atomic(lock, block, bh->b_data); |
| 770 | ret = 0; |
| 771 | } else { |
| 772 | ret = 1; |
| 773 | } |
| 774 | jbd_unlock_bh_state(bh); |
| 775 | return ret; |
| 776 | } |
| 777 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 778 | /** |
| 779 | * ext3_try_to_allocate() |
| 780 | * @sb: superblock |
| 781 | * @handle: handle to this transaction |
| 782 | * @group: given allocation block group |
| 783 | * @bitmap_bh: bufferhead holds the block bitmap |
| 784 | * @grp_goal: given target block within the group |
| 785 | * @count: target number of blocks to allocate |
| 786 | * @my_rsv: reservation window |
| 787 | * |
| 788 | * Attempt to allocate blocks within a give range. Set the range of allocation |
| 789 | * first, then find the first free bit(s) from the bitmap (within the range), |
| 790 | * and at last, allocate the blocks by claiming the found free bit as allocated. |
| 791 | * |
| 792 | * To set the range of this allocation: |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 793 | * if there is a reservation window, only try to allocate block(s) from the |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 794 | * file's own reservation window; |
| 795 | * Otherwise, the allocation range starts from the give goal block, ends at |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 796 | * the block group's last block. |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 797 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | * If we failed to allocate the desired block then we may end up crossing to a |
| 799 | * new bitmap. In that case we must release write access to the old one via |
| 800 | * ext3_journal_release_buffer(), else we'll run out of credits. |
| 801 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 802 | static ext3_grpblk_t |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | ext3_try_to_allocate(struct super_block *sb, handle_t *handle, int group, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 804 | struct buffer_head *bitmap_bh, ext3_grpblk_t grp_goal, |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 805 | unsigned long *count, struct ext3_reserve_window *my_rsv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 807 | ext3_fsblk_t group_first_block; |
| 808 | ext3_grpblk_t start, end; |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 809 | unsigned long num = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | |
| 811 | /* we do allocation within the reservation window if we have a window */ |
| 812 | if (my_rsv) { |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 813 | group_first_block = ext3_group_first_block_no(sb, group); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | if (my_rsv->_rsv_start >= group_first_block) |
| 815 | start = my_rsv->_rsv_start - group_first_block; |
| 816 | else |
| 817 | /* reservation window cross group boundary */ |
| 818 | start = 0; |
| 819 | end = my_rsv->_rsv_end - group_first_block + 1; |
| 820 | if (end > EXT3_BLOCKS_PER_GROUP(sb)) |
| 821 | /* reservation window crosses group boundary */ |
| 822 | end = EXT3_BLOCKS_PER_GROUP(sb); |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 823 | if ((start <= grp_goal) && (grp_goal < end)) |
| 824 | start = grp_goal; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | else |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 826 | grp_goal = -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } else { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 828 | if (grp_goal > 0) |
| 829 | start = grp_goal; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | else |
| 831 | start = 0; |
| 832 | end = EXT3_BLOCKS_PER_GROUP(sb); |
| 833 | } |
| 834 | |
| 835 | BUG_ON(start > EXT3_BLOCKS_PER_GROUP(sb)); |
| 836 | |
| 837 | repeat: |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 838 | if (grp_goal < 0 || !ext3_test_allocatable(grp_goal, bitmap_bh)) { |
| 839 | grp_goal = find_next_usable_block(start, bitmap_bh, end); |
| 840 | if (grp_goal < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | goto fail_access; |
| 842 | if (!my_rsv) { |
| 843 | int i; |
| 844 | |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 845 | for (i = 0; i < 7 && grp_goal > start && |
| 846 | ext3_test_allocatable(grp_goal - 1, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 847 | bitmap_bh); |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 848 | i++, grp_goal--) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | ; |
| 850 | } |
| 851 | } |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 852 | start = grp_goal; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 854 | if (!claim_block(sb_bgl_lock(EXT3_SB(sb), group), |
| 855 | grp_goal, bitmap_bh)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | /* |
| 857 | * The block was allocated by another thread, or it was |
| 858 | * allocated and then freed by another thread |
| 859 | */ |
| 860 | start++; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 861 | grp_goal++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | if (start >= end) |
| 863 | goto fail_access; |
| 864 | goto repeat; |
| 865 | } |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 866 | num++; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 867 | grp_goal++; |
| 868 | while (num < *count && grp_goal < end |
| 869 | && ext3_test_allocatable(grp_goal, bitmap_bh) |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 870 | && claim_block(sb_bgl_lock(EXT3_SB(sb), group), |
| 871 | grp_goal, bitmap_bh)) { |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 872 | num++; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 873 | grp_goal++; |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 874 | } |
| 875 | *count = num; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 876 | return grp_goal - num; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 877 | fail_access: |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 878 | *count = num; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | return -1; |
| 880 | } |
| 881 | |
| 882 | /** |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 883 | * find_next_reservable_window(): |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 884 | * find a reservable space within the given range. |
| 885 | * It does not allocate the reservation window for now: |
| 886 | * alloc_new_reservation() will do the work later. |
| 887 | * |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 888 | * @search_head: the head of the searching list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 889 | * This is not necessarily the list head of the whole filesystem |
| 890 | * |
| 891 | * We have both head and start_block to assist the search |
| 892 | * for the reservable space. The list starts from head, |
| 893 | * but we will shift to the place where start_block is, |
| 894 | * then start from there, when looking for a reservable space. |
| 895 | * |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 896 | * @size: the target new reservation window size |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | * |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 898 | * @group_first_block: the first block we consider to start |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | * the real search from |
| 900 | * |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 901 | * @last_block: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | * the maximum block number that our goal reservable space |
| 903 | * could start from. This is normally the last block in this |
| 904 | * group. The search will end when we found the start of next |
| 905 | * possible reservable space is out of this boundary. |
| 906 | * This could handle the cross boundary reservation window |
| 907 | * request. |
| 908 | * |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 909 | * basically we search from the given range, rather than the whole |
| 910 | * reservation double linked list, (start_block, last_block) |
| 911 | * to find a free region that is of my size and has not |
| 912 | * been reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 913 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | */ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 915 | static int find_next_reservable_window( |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | struct ext3_reserve_window_node *search_head, |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 917 | struct ext3_reserve_window_node *my_rsv, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 918 | struct super_block * sb, |
| 919 | ext3_fsblk_t start_block, |
| 920 | ext3_fsblk_t last_block) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | { |
| 922 | struct rb_node *next; |
| 923 | struct ext3_reserve_window_node *rsv, *prev; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 924 | ext3_fsblk_t cur; |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 925 | int size = my_rsv->rsv_goal_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | |
| 927 | /* TODO: make the start of the reservation window byte-aligned */ |
| 928 | /* cur = *start_block & ~7;*/ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 929 | cur = start_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | rsv = search_head; |
| 931 | if (!rsv) |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 932 | return -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 933 | |
| 934 | while (1) { |
| 935 | if (cur <= rsv->rsv_end) |
| 936 | cur = rsv->rsv_end + 1; |
| 937 | |
| 938 | /* TODO? |
| 939 | * in the case we could not find a reservable space |
| 940 | * that is what is expected, during the re-search, we could |
| 941 | * remember what's the largest reservable space we could have |
| 942 | * and return that one. |
| 943 | * |
| 944 | * For now it will fail if we could not find the reservable |
| 945 | * space with expected-size (or more)... |
| 946 | */ |
| 947 | if (cur > last_block) |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 948 | return -1; /* fail */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 949 | |
| 950 | prev = rsv; |
| 951 | next = rb_next(&rsv->rsv_node); |
Hugh Dickins | c56d256 | 2006-12-06 20:41:27 -0800 | [diff] [blame] | 952 | rsv = rb_entry(next,struct ext3_reserve_window_node,rsv_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | |
| 954 | /* |
| 955 | * Reached the last reservation, we can just append to the |
| 956 | * previous one. |
| 957 | */ |
| 958 | if (!next) |
| 959 | break; |
| 960 | |
| 961 | if (cur + size <= rsv->rsv_start) { |
| 962 | /* |
| 963 | * Found a reserveable space big enough. We could |
| 964 | * have a reservation across the group boundary here |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 965 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | break; |
| 967 | } |
| 968 | } |
| 969 | /* |
| 970 | * we come here either : |
| 971 | * when we reach the end of the whole list, |
| 972 | * and there is empty reservable space after last entry in the list. |
| 973 | * append it to the end of the list. |
| 974 | * |
| 975 | * or we found one reservable space in the middle of the list, |
| 976 | * return the reservation window that we could append to. |
| 977 | * succeed. |
| 978 | */ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 979 | |
| 980 | if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) |
| 981 | rsv_window_remove(sb, my_rsv); |
| 982 | |
| 983 | /* |
| 984 | * Let's book the whole avaliable window for now. We will check the |
| 985 | * disk bitmap later and then, if there are free blocks then we adjust |
| 986 | * the window size if it's larger than requested. |
| 987 | * Otherwise, we will remove this node from the tree next time |
| 988 | * call find_next_reservable_window. |
| 989 | */ |
| 990 | my_rsv->rsv_start = cur; |
| 991 | my_rsv->rsv_end = cur + size - 1; |
| 992 | my_rsv->rsv_alloc_hit = 0; |
| 993 | |
| 994 | if (prev != my_rsv) |
| 995 | ext3_rsv_window_add(sb, my_rsv); |
| 996 | |
| 997 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | } |
| 999 | |
| 1000 | /** |
Dave Kleikamp | e9ad562 | 2006-09-27 01:49:35 -0700 | [diff] [blame] | 1001 | * alloc_new_reservation()--allocate a new reservation window |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1002 | * |
| 1003 | * To make a new reservation, we search part of the filesystem |
| 1004 | * reservation list (the list that inside the group). We try to |
| 1005 | * allocate a new reservation window near the allocation goal, |
| 1006 | * or the beginning of the group, if there is no goal. |
| 1007 | * |
| 1008 | * We first find a reservable space after the goal, then from |
| 1009 | * there, we check the bitmap for the first free block after |
| 1010 | * it. If there is no free block until the end of group, then the |
| 1011 | * whole group is full, we failed. Otherwise, check if the free |
| 1012 | * block is inside the expected reservable space, if so, we |
| 1013 | * succeed. |
| 1014 | * If the first free block is outside the reservable space, then |
| 1015 | * start from the first free block, we search for next available |
| 1016 | * space, and go on. |
| 1017 | * |
| 1018 | * on succeed, a new reservation will be found and inserted into the list |
| 1019 | * It contains at least one free block, and it does not overlap with other |
| 1020 | * reservation windows. |
| 1021 | * |
| 1022 | * failed: we failed to find a reservation window in this group |
| 1023 | * |
| 1024 | * @rsv: the reservation |
| 1025 | * |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1026 | * @grp_goal: The goal (group-relative). It is where the search for a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | * free reservable space should start from. |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1028 | * if we have a grp_goal(grp_goal >0 ), then start from there, |
| 1029 | * no grp_goal(grp_goal = -1), we start from the first block |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | * of the group. |
| 1031 | * |
| 1032 | * @sb: the super block |
| 1033 | * @group: the group we are trying to allocate in |
| 1034 | * @bitmap_bh: the block group block bitmap |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1035 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1036 | */ |
| 1037 | static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1038 | ext3_grpblk_t grp_goal, struct super_block *sb, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | unsigned int group, struct buffer_head *bitmap_bh) |
| 1040 | { |
| 1041 | struct ext3_reserve_window_node *search_head; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1042 | ext3_fsblk_t group_first_block, group_end_block, start_block; |
| 1043 | ext3_grpblk_t first_free_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1044 | struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root; |
| 1045 | unsigned long size; |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1046 | int ret; |
| 1047 | spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1049 | group_first_block = ext3_group_first_block_no(sb, group); |
Eric Sandeen | 32c2d2b | 2006-09-27 01:49:36 -0700 | [diff] [blame] | 1050 | group_end_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1052 | if (grp_goal < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1053 | start_block = group_first_block; |
| 1054 | else |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1055 | start_block = grp_goal + group_first_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1056 | |
| 1057 | size = my_rsv->rsv_goal_size; |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1058 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | if (!rsv_is_empty(&my_rsv->rsv_window)) { |
| 1060 | /* |
| 1061 | * if the old reservation is cross group boundary |
| 1062 | * and if the goal is inside the old reservation window, |
| 1063 | * we will come here when we just failed to allocate from |
| 1064 | * the first part of the window. We still have another part |
| 1065 | * that belongs to the next group. In this case, there is no |
| 1066 | * point to discard our window and try to allocate a new one |
| 1067 | * in this group(which will fail). we should |
| 1068 | * keep the reservation window, just simply move on. |
| 1069 | * |
| 1070 | * Maybe we could shift the start block of the reservation |
| 1071 | * window to the first block of next group. |
| 1072 | */ |
| 1073 | |
| 1074 | if ((my_rsv->rsv_start <= group_end_block) && |
| 1075 | (my_rsv->rsv_end > group_end_block) && |
| 1076 | (start_block >= my_rsv->rsv_start)) |
| 1077 | return -1; |
| 1078 | |
| 1079 | if ((my_rsv->rsv_alloc_hit > |
| 1080 | (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { |
| 1081 | /* |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1082 | * if the previously allocation hit ratio is |
| 1083 | * greater than 1/2, then we double the size of |
| 1084 | * the reservation window the next time, |
| 1085 | * otherwise we keep the same size window |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | */ |
| 1087 | size = size * 2; |
| 1088 | if (size > EXT3_MAX_RESERVE_BLOCKS) |
| 1089 | size = EXT3_MAX_RESERVE_BLOCKS; |
| 1090 | my_rsv->rsv_goal_size= size; |
| 1091 | } |
| 1092 | } |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1093 | |
| 1094 | spin_lock(rsv_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1095 | /* |
| 1096 | * shift the search start to the window near the goal block |
| 1097 | */ |
| 1098 | search_head = search_reserve_window(fs_rsv_root, start_block); |
| 1099 | |
| 1100 | /* |
| 1101 | * find_next_reservable_window() simply finds a reservable window |
| 1102 | * inside the given range(start_block, group_end_block). |
| 1103 | * |
| 1104 | * To make sure the reservation window has a free bit inside it, we |
| 1105 | * need to check the bitmap after we found a reservable window. |
| 1106 | */ |
| 1107 | retry: |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1108 | ret = find_next_reservable_window(search_head, my_rsv, sb, |
| 1109 | start_block, group_end_block); |
| 1110 | |
| 1111 | if (ret == -1) { |
| 1112 | if (!rsv_is_empty(&my_rsv->rsv_window)) |
| 1113 | rsv_window_remove(sb, my_rsv); |
| 1114 | spin_unlock(rsv_lock); |
| 1115 | return -1; |
| 1116 | } |
| 1117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | /* |
| 1119 | * On success, find_next_reservable_window() returns the |
| 1120 | * reservation window where there is a reservable space after it. |
| 1121 | * Before we reserve this reservable space, we need |
| 1122 | * to make sure there is at least a free block inside this region. |
| 1123 | * |
| 1124 | * searching the first free bit on the block bitmap and copy of |
| 1125 | * last committed bitmap alternatively, until we found a allocatable |
| 1126 | * block. Search start from the start block of the reservable space |
| 1127 | * we just found. |
| 1128 | */ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1129 | spin_unlock(rsv_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | first_free_block = bitmap_search_next_usable_block( |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1131 | my_rsv->rsv_start - group_first_block, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | bitmap_bh, group_end_block - group_first_block + 1); |
| 1133 | |
| 1134 | if (first_free_block < 0) { |
| 1135 | /* |
| 1136 | * no free block left on the bitmap, no point |
| 1137 | * to reserve the space. return failed. |
| 1138 | */ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1139 | spin_lock(rsv_lock); |
| 1140 | if (!rsv_is_empty(&my_rsv->rsv_window)) |
| 1141 | rsv_window_remove(sb, my_rsv); |
| 1142 | spin_unlock(rsv_lock); |
| 1143 | return -1; /* failed */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | } |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1145 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1146 | start_block = first_free_block + group_first_block; |
| 1147 | /* |
| 1148 | * check if the first free block is within the |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1149 | * free space we just reserved |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | */ |
Hugh Dickins | ff50dc5 | 2006-12-06 20:41:25 -0800 | [diff] [blame] | 1151 | if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end) |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1152 | return 0; /* success */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1153 | /* |
| 1154 | * if the first free bit we found is out of the reservable space |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1155 | * continue search for next reservable space, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | * start from where the free block is, |
| 1157 | * we also shift the list head to where we stopped last time |
| 1158 | */ |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1159 | search_head = my_rsv; |
| 1160 | spin_lock(rsv_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1161 | goto retry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | } |
| 1163 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1164 | /** |
| 1165 | * try_to_extend_reservation() |
| 1166 | * @my_rsv: given reservation window |
| 1167 | * @sb: super block |
| 1168 | * @size: the delta to extend |
| 1169 | * |
| 1170 | * Attempt to expand the reservation window large enough to have |
| 1171 | * required number of free blocks |
| 1172 | * |
| 1173 | * Since ext3_try_to_allocate() will always allocate blocks within |
| 1174 | * the reservation window range, if the window size is too small, |
| 1175 | * multiple blocks allocation has to stop at the end of the reservation |
| 1176 | * window. To make this more efficient, given the total number of |
| 1177 | * blocks needed and the current size of the window, we try to |
| 1178 | * expand the reservation window size if necessary on a best-effort |
| 1179 | * basis before ext3_new_blocks() tries to allocate blocks, |
| 1180 | */ |
Mingming Cao | d48589b | 2006-03-26 01:37:59 -0800 | [diff] [blame] | 1181 | static void try_to_extend_reservation(struct ext3_reserve_window_node *my_rsv, |
| 1182 | struct super_block *sb, int size) |
| 1183 | { |
| 1184 | struct ext3_reserve_window_node *next_rsv; |
| 1185 | struct rb_node *next; |
| 1186 | spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock; |
| 1187 | |
| 1188 | if (!spin_trylock(rsv_lock)) |
| 1189 | return; |
| 1190 | |
| 1191 | next = rb_next(&my_rsv->rsv_node); |
| 1192 | |
| 1193 | if (!next) |
| 1194 | my_rsv->rsv_end += size; |
| 1195 | else { |
Hugh Dickins | c56d256 | 2006-12-06 20:41:27 -0800 | [diff] [blame] | 1196 | next_rsv = rb_entry(next, struct ext3_reserve_window_node, rsv_node); |
Mingming Cao | d48589b | 2006-03-26 01:37:59 -0800 | [diff] [blame] | 1197 | |
| 1198 | if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) |
| 1199 | my_rsv->rsv_end += size; |
| 1200 | else |
| 1201 | my_rsv->rsv_end = next_rsv->rsv_start - 1; |
| 1202 | } |
| 1203 | spin_unlock(rsv_lock); |
| 1204 | } |
| 1205 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1206 | /** |
| 1207 | * ext3_try_to_allocate_with_rsv() |
| 1208 | * @sb: superblock |
| 1209 | * @handle: handle to this transaction |
| 1210 | * @group: given allocation block group |
| 1211 | * @bitmap_bh: bufferhead holds the block bitmap |
| 1212 | * @grp_goal: given target block within the group |
| 1213 | * @count: target number of blocks to allocate |
| 1214 | * @my_rsv: reservation window |
| 1215 | * @errp: pointer to store the error code |
| 1216 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | * This is the main function used to allocate a new block and its reservation |
| 1218 | * window. |
| 1219 | * |
| 1220 | * Each time when a new block allocation is need, first try to allocate from |
| 1221 | * its own reservation. If it does not have a reservation window, instead of |
| 1222 | * looking for a free bit on bitmap first, then look up the reservation list to |
| 1223 | * see if it is inside somebody else's reservation window, we try to allocate a |
| 1224 | * reservation window for it starting from the goal first. Then do the block |
| 1225 | * allocation within the reservation window. |
| 1226 | * |
| 1227 | * This will avoid keeping on searching the reservation list again and |
Glauber de Oliveira Costa | 5b11687 | 2005-10-30 15:02:48 -0800 | [diff] [blame] | 1228 | * again when somebody is looking for a free block (without |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1229 | * reservation), and there are lots of free blocks, but they are all |
| 1230 | * being reserved. |
| 1231 | * |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1232 | * We use a red-black tree for the per-filesystem reservation list. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | * |
| 1234 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1235 | static ext3_grpblk_t |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1236 | ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, |
| 1237 | unsigned int group, struct buffer_head *bitmap_bh, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1238 | ext3_grpblk_t grp_goal, |
| 1239 | struct ext3_reserve_window_node * my_rsv, |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1240 | unsigned long *count, int *errp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | { |
Eric Sandeen | 32c2d2b | 2006-09-27 01:49:36 -0700 | [diff] [blame] | 1242 | ext3_fsblk_t group_first_block, group_last_block; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1243 | ext3_grpblk_t ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | int fatal; |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1245 | unsigned long num = *count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | |
| 1247 | *errp = 0; |
| 1248 | |
| 1249 | /* |
| 1250 | * Make sure we use undo access for the bitmap, because it is critical |
| 1251 | * that we do the frozen_data COW on bitmap buffers in all cases even |
| 1252 | * if the buffer is in BJ_Forget state in the committing transaction. |
| 1253 | */ |
| 1254 | BUFFER_TRACE(bitmap_bh, "get undo access for new block"); |
| 1255 | fatal = ext3_journal_get_undo_access(handle, bitmap_bh); |
| 1256 | if (fatal) { |
| 1257 | *errp = fatal; |
| 1258 | return -1; |
| 1259 | } |
| 1260 | |
| 1261 | /* |
| 1262 | * we don't deal with reservation when |
| 1263 | * filesystem is mounted without reservation |
| 1264 | * or the file is not a regular file |
| 1265 | * or last attempt to allocate a block with reservation turned on failed |
| 1266 | */ |
| 1267 | if (my_rsv == NULL ) { |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1268 | ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1269 | grp_goal, count, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1270 | goto out; |
| 1271 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | /* |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1273 | * grp_goal is a group relative block number (if there is a goal) |
Hugh Dickins | 1650242 | 2006-12-06 20:41:25 -0800 | [diff] [blame] | 1274 | * 0 <= grp_goal < EXT3_BLOCKS_PER_GROUP(sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | * first block is a filesystem wide block number |
| 1276 | * first block is the block number of the first block in this group |
| 1277 | */ |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1278 | group_first_block = ext3_group_first_block_no(sb, group); |
Eric Sandeen | 32c2d2b | 2006-09-27 01:49:36 -0700 | [diff] [blame] | 1279 | group_last_block = group_first_block + (EXT3_BLOCKS_PER_GROUP(sb) - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | |
| 1281 | /* |
| 1282 | * Basically we will allocate a new block from inode's reservation |
| 1283 | * window. |
| 1284 | * |
| 1285 | * We need to allocate a new reservation window, if: |
| 1286 | * a) inode does not have a reservation window; or |
| 1287 | * b) last attempt to allocate a block from existing reservation |
| 1288 | * failed; or |
| 1289 | * c) we come here with a goal and with a reservation window |
| 1290 | * |
| 1291 | * We do not need to allocate a new reservation window if we come here |
| 1292 | * at the beginning with a goal and the goal is inside the window, or |
| 1293 | * we don't have a goal but already have a reservation window. |
| 1294 | * then we could go to allocate from the reservation window directly. |
| 1295 | */ |
| 1296 | while (1) { |
Mingming Cao | 21fe347 | 2005-06-28 20:45:16 -0700 | [diff] [blame] | 1297 | if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1298 | !goal_in_my_reservation(&my_rsv->rsv_window, |
| 1299 | grp_goal, group, sb)) { |
Mingming Cao | d48589b | 2006-03-26 01:37:59 -0800 | [diff] [blame] | 1300 | if (my_rsv->rsv_goal_size < *count) |
| 1301 | my_rsv->rsv_goal_size = *count; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1302 | ret = alloc_new_reservation(my_rsv, grp_goal, sb, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | group, bitmap_bh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | if (ret < 0) |
| 1305 | break; /* failed */ |
| 1306 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1307 | if (!goal_in_my_reservation(&my_rsv->rsv_window, |
| 1308 | grp_goal, group, sb)) |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1309 | grp_goal = -1; |
Hugh Dickins | 1650242 | 2006-12-06 20:41:25 -0800 | [diff] [blame] | 1310 | } else if (grp_goal >= 0) { |
Mingming Cao | 2bd94bd | 2006-12-06 20:38:18 -0800 | [diff] [blame] | 1311 | int curr = my_rsv->rsv_end - |
| 1312 | (grp_goal + group_first_block) + 1; |
| 1313 | |
| 1314 | if (curr < *count) |
| 1315 | try_to_extend_reservation(my_rsv, sb, |
| 1316 | *count - curr); |
| 1317 | } |
Mingming Cao | d48589b | 2006-03-26 01:37:59 -0800 | [diff] [blame] | 1318 | |
Eric Sandeen | 32c2d2b | 2006-09-27 01:49:36 -0700 | [diff] [blame] | 1319 | if ((my_rsv->rsv_start > group_last_block) || |
| 1320 | (my_rsv->rsv_end < group_first_block)) { |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1321 | rsv_window_dump(&EXT3_SB(sb)->s_rsv_window_root, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1322 | BUG(); |
Mingming Cao | 321fb9e | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1323 | } |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1324 | ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, |
| 1325 | grp_goal, &num, &my_rsv->rsv_window); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | if (ret >= 0) { |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1327 | my_rsv->rsv_alloc_hit += num; |
| 1328 | *count = num; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | break; /* succeed */ |
| 1330 | } |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1331 | num = *count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1332 | } |
| 1333 | out: |
| 1334 | if (ret >= 0) { |
| 1335 | BUFFER_TRACE(bitmap_bh, "journal_dirty_metadata for " |
| 1336 | "bitmap block"); |
| 1337 | fatal = ext3_journal_dirty_metadata(handle, bitmap_bh); |
| 1338 | if (fatal) { |
| 1339 | *errp = fatal; |
| 1340 | return -1; |
| 1341 | } |
| 1342 | return ret; |
| 1343 | } |
| 1344 | |
| 1345 | BUFFER_TRACE(bitmap_bh, "journal_release_buffer"); |
| 1346 | ext3_journal_release_buffer(handle, bitmap_bh); |
| 1347 | return ret; |
| 1348 | } |
| 1349 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1350 | /** |
| 1351 | * ext3_has_free_blocks() |
| 1352 | * @sbi: in-core super block structure. |
| 1353 | * |
| 1354 | * Check if filesystem has at least 1 free block available for allocation. |
| 1355 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | static int ext3_has_free_blocks(struct ext3_sb_info *sbi) |
| 1357 | { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1358 | ext3_fsblk_t free_blocks, root_blocks; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | |
| 1360 | free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); |
| 1361 | root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); |
| 1362 | if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && |
| 1363 | sbi->s_resuid != current->fsuid && |
| 1364 | (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { |
| 1365 | return 0; |
| 1366 | } |
| 1367 | return 1; |
| 1368 | } |
| 1369 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1370 | /** |
| 1371 | * ext3_should_retry_alloc() |
| 1372 | * @sb: super block |
| 1373 | * @retries number of attemps has been made |
| 1374 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | * ext3_should_retry_alloc() is called when ENOSPC is returned, and if |
| 1376 | * it is profitable to retry the operation, this function will wait |
| 1377 | * for the current or commiting transaction to complete, and then |
| 1378 | * return TRUE. |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1379 | * |
| 1380 | * if the total number of retries exceed three times, return FALSE. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | */ |
| 1382 | int ext3_should_retry_alloc(struct super_block *sb, int *retries) |
| 1383 | { |
| 1384 | if (!ext3_has_free_blocks(EXT3_SB(sb)) || (*retries)++ > 3) |
| 1385 | return 0; |
| 1386 | |
| 1387 | jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); |
| 1388 | |
| 1389 | return journal_force_commit_nested(EXT3_SB(sb)->s_journal); |
| 1390 | } |
| 1391 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1392 | /** |
| 1393 | * ext3_new_blocks() -- core block(s) allocation function |
| 1394 | * @handle: handle to this transaction |
| 1395 | * @inode: file inode |
| 1396 | * @goal: given target block(filesystem wide) |
| 1397 | * @count: target number of blocks to allocate |
| 1398 | * @errp: error code |
| 1399 | * |
| 1400 | * ext3_new_blocks uses a goal block to assist allocation. It tries to |
| 1401 | * allocate block(s) from the block group contains the goal block first. If that |
| 1402 | * fails, it will try to allocate block(s) from other block groups without |
| 1403 | * any specific goal block. |
| 1404 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1405 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1406 | ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode, |
| 1407 | ext3_fsblk_t goal, unsigned long *count, int *errp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | { |
| 1409 | struct buffer_head *bitmap_bh = NULL; |
| 1410 | struct buffer_head *gdp_bh; |
| 1411 | int group_no; |
| 1412 | int goal_group; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1413 | ext3_grpblk_t grp_target_blk; /* blockgroup relative goal block */ |
| 1414 | ext3_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ |
| 1415 | ext3_fsblk_t ret_block; /* filesyetem-wide allocated block */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | int bgi; /* blockgroup iteration index */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | int fatal = 0, err; |
| 1418 | int performed_allocation = 0; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1419 | ext3_grpblk_t free_blocks; /* number of free blocks in a group */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | struct super_block *sb; |
| 1421 | struct ext3_group_desc *gdp; |
| 1422 | struct ext3_super_block *es; |
| 1423 | struct ext3_sb_info *sbi; |
| 1424 | struct ext3_reserve_window_node *my_rsv = NULL; |
| 1425 | struct ext3_block_alloc_info *block_i; |
| 1426 | unsigned short windowsz = 0; |
| 1427 | #ifdef EXT3FS_DEBUG |
| 1428 | static int goal_hits, goal_attempts; |
| 1429 | #endif |
| 1430 | unsigned long ngroups; |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1431 | unsigned long num = *count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1432 | |
| 1433 | *errp = -ENOSPC; |
| 1434 | sb = inode->i_sb; |
| 1435 | if (!sb) { |
| 1436 | printk("ext3_new_block: nonexistent device"); |
| 1437 | return 0; |
| 1438 | } |
| 1439 | |
| 1440 | /* |
| 1441 | * Check quota for allocation of this block. |
| 1442 | */ |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1443 | if (DQUOT_ALLOC_BLOCK(inode, num)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1444 | *errp = -EDQUOT; |
| 1445 | return 0; |
| 1446 | } |
| 1447 | |
| 1448 | sbi = EXT3_SB(sb); |
| 1449 | es = EXT3_SB(sb)->s_es; |
| 1450 | ext3_debug("goal=%lu.\n", goal); |
| 1451 | /* |
| 1452 | * Allocate a block from reservation only when |
| 1453 | * filesystem is mounted with reservation(default,-o reservation), and |
| 1454 | * it's a regular file, and |
| 1455 | * the desired window size is greater than 0 (One could use ioctl |
| 1456 | * command EXT3_IOC_SETRSVSZ to set the window size to 0 to turn off |
| 1457 | * reservation on that particular file) |
| 1458 | */ |
| 1459 | block_i = EXT3_I(inode)->i_block_alloc_info; |
| 1460 | if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0)) |
| 1461 | my_rsv = &block_i->rsv_window_node; |
| 1462 | |
| 1463 | if (!ext3_has_free_blocks(sbi)) { |
| 1464 | *errp = -ENOSPC; |
| 1465 | goto out; |
| 1466 | } |
| 1467 | |
| 1468 | /* |
| 1469 | * First, test whether the goal block is free. |
| 1470 | */ |
| 1471 | if (goal < le32_to_cpu(es->s_first_data_block) || |
| 1472 | goal >= le32_to_cpu(es->s_blocks_count)) |
| 1473 | goal = le32_to_cpu(es->s_first_data_block); |
| 1474 | group_no = (goal - le32_to_cpu(es->s_first_data_block)) / |
| 1475 | EXT3_BLOCKS_PER_GROUP(sb); |
Mingming Cao | 08fb306f | 2006-08-27 01:23:44 -0700 | [diff] [blame] | 1476 | goal_group = group_no; |
| 1477 | retry_alloc: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | gdp = ext3_get_group_desc(sb, group_no, &gdp_bh); |
| 1479 | if (!gdp) |
| 1480 | goto io_error; |
| 1481 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
| 1483 | /* |
| 1484 | * if there is not enough free blocks to make a new resevation |
| 1485 | * turn off reservation for this allocation |
| 1486 | */ |
| 1487 | if (my_rsv && (free_blocks < windowsz) |
| 1488 | && (rsv_is_empty(&my_rsv->rsv_window))) |
| 1489 | my_rsv = NULL; |
| 1490 | |
| 1491 | if (free_blocks > 0) { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1492 | grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) % |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | EXT3_BLOCKS_PER_GROUP(sb)); |
| 1494 | bitmap_bh = read_block_bitmap(sb, group_no); |
| 1495 | if (!bitmap_bh) |
| 1496 | goto io_error; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1497 | grp_alloc_blk = ext3_try_to_allocate_with_rsv(sb, handle, |
| 1498 | group_no, bitmap_bh, grp_target_blk, |
| 1499 | my_rsv, &num, &fatal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1500 | if (fatal) |
| 1501 | goto out; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1502 | if (grp_alloc_blk >= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | goto allocated; |
| 1504 | } |
| 1505 | |
| 1506 | ngroups = EXT3_SB(sb)->s_groups_count; |
| 1507 | smp_rmb(); |
| 1508 | |
| 1509 | /* |
Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 1510 | * Now search the rest of the groups. We assume that |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1511 | * i and gdp correctly point to the last group visited. |
| 1512 | */ |
| 1513 | for (bgi = 0; bgi < ngroups; bgi++) { |
| 1514 | group_no++; |
| 1515 | if (group_no >= ngroups) |
| 1516 | group_no = 0; |
| 1517 | gdp = ext3_get_group_desc(sb, group_no, &gdp_bh); |
Hugh Dickins | 2823b55 | 2006-12-06 20:41:28 -0800 | [diff] [blame] | 1518 | if (!gdp) |
| 1519 | goto io_error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1520 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
| 1521 | /* |
| 1522 | * skip this group if the number of |
| 1523 | * free blocks is less than half of the reservation |
| 1524 | * window size. |
| 1525 | */ |
| 1526 | if (free_blocks <= (windowsz/2)) |
| 1527 | continue; |
| 1528 | |
| 1529 | brelse(bitmap_bh); |
| 1530 | bitmap_bh = read_block_bitmap(sb, group_no); |
| 1531 | if (!bitmap_bh) |
| 1532 | goto io_error; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1533 | /* |
| 1534 | * try to allocate block(s) from this group, without a goal(-1). |
| 1535 | */ |
| 1536 | grp_alloc_blk = ext3_try_to_allocate_with_rsv(sb, handle, |
| 1537 | group_no, bitmap_bh, -1, my_rsv, |
| 1538 | &num, &fatal); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1539 | if (fatal) |
| 1540 | goto out; |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1541 | if (grp_alloc_blk >= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | goto allocated; |
| 1543 | } |
| 1544 | /* |
| 1545 | * We may end up a bogus ealier ENOSPC error due to |
| 1546 | * filesystem is "full" of reservations, but |
| 1547 | * there maybe indeed free blocks avaliable on disk |
| 1548 | * In this case, we just forget about the reservations |
| 1549 | * just do block allocation as without reservations. |
| 1550 | */ |
| 1551 | if (my_rsv) { |
| 1552 | my_rsv = NULL; |
Hugh Dickins | ef50367 | 2006-12-06 20:41:23 -0800 | [diff] [blame] | 1553 | windowsz = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1554 | group_no = goal_group; |
Mingming Cao | 08fb306f | 2006-08-27 01:23:44 -0700 | [diff] [blame] | 1555 | goto retry_alloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1556 | } |
| 1557 | /* No space left on the device */ |
| 1558 | *errp = -ENOSPC; |
| 1559 | goto out; |
| 1560 | |
| 1561 | allocated: |
| 1562 | |
| 1563 | ext3_debug("using block group %d(%d)\n", |
| 1564 | group_no, gdp->bg_free_blocks_count); |
| 1565 | |
| 1566 | BUFFER_TRACE(gdp_bh, "get_write_access"); |
| 1567 | fatal = ext3_journal_get_write_access(handle, gdp_bh); |
| 1568 | if (fatal) |
| 1569 | goto out; |
| 1570 | |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1571 | ret_block = grp_alloc_blk + ext3_group_first_block_no(sb, group_no); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1572 | |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1573 | if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) || |
| 1574 | in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) || |
| 1575 | in_range(ret_block, le32_to_cpu(gdp->bg_inode_table), |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1576 | EXT3_SB(sb)->s_itb_per_group) || |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1577 | in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1578 | EXT3_SB(sb)->s_itb_per_group)) |
| 1579 | ext3_error(sb, "ext3_new_block", |
| 1580 | "Allocating block in system zone - " |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1581 | "blocks from "E3FSBLK", length %lu", |
| 1582 | ret_block, num); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1583 | |
| 1584 | performed_allocation = 1; |
| 1585 | |
| 1586 | #ifdef CONFIG_JBD_DEBUG |
| 1587 | { |
| 1588 | struct buffer_head *debug_bh; |
| 1589 | |
| 1590 | /* Record bitmap buffer state in the newly allocated block */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1591 | debug_bh = sb_find_get_block(sb, ret_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1592 | if (debug_bh) { |
| 1593 | BUFFER_TRACE(debug_bh, "state when allocated"); |
| 1594 | BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state"); |
| 1595 | brelse(debug_bh); |
| 1596 | } |
| 1597 | } |
| 1598 | jbd_lock_bh_state(bitmap_bh); |
| 1599 | spin_lock(sb_bgl_lock(sbi, group_no)); |
| 1600 | if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) { |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1601 | int i; |
| 1602 | |
| 1603 | for (i = 0; i < num; i++) { |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1604 | if (ext3_test_bit(grp_alloc_blk+i, |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1605 | bh2jh(bitmap_bh)->b_committed_data)) { |
| 1606 | printk("%s: block was unexpectedly set in " |
| 1607 | "b_committed_data\n", __FUNCTION__); |
| 1608 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1609 | } |
| 1610 | } |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1611 | ext3_debug("found bit %d\n", grp_alloc_blk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1612 | spin_unlock(sb_bgl_lock(sbi, group_no)); |
| 1613 | jbd_unlock_bh_state(bitmap_bh); |
| 1614 | #endif |
| 1615 | |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1616 | if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1617 | ext3_error(sb, "ext3_new_block", |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1618 | "block("E3FSBLK") >= blocks count(%d) - " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1619 | "block_group = %d, es == %p ", ret_block, |
| 1620 | le32_to_cpu(es->s_blocks_count), group_no, es); |
| 1621 | goto out; |
| 1622 | } |
| 1623 | |
| 1624 | /* |
| 1625 | * It is up to the caller to add the new buffer to a journal |
| 1626 | * list of some description. We don't know in advance whether |
| 1627 | * the caller wants to use it as metadata or data. |
| 1628 | */ |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1629 | ext3_debug("allocating block %lu. Goal hits %d of %d.\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | ret_block, goal_hits, goal_attempts); |
| 1631 | |
| 1632 | spin_lock(sb_bgl_lock(sbi, group_no)); |
| 1633 | gdp->bg_free_blocks_count = |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1634 | cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)-num); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | spin_unlock(sb_bgl_lock(sbi, group_no)); |
Peter Zijlstra | 3cb4f9f | 2007-10-16 23:25:42 -0700 | [diff] [blame^] | 1636 | percpu_counter_sub(&sbi->s_freeblocks_counter, num); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1637 | |
| 1638 | BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor"); |
| 1639 | err = ext3_journal_dirty_metadata(handle, gdp_bh); |
| 1640 | if (!fatal) |
| 1641 | fatal = err; |
| 1642 | |
| 1643 | sb->s_dirt = 1; |
| 1644 | if (fatal) |
| 1645 | goto out; |
| 1646 | |
| 1647 | *errp = 0; |
| 1648 | brelse(bitmap_bh); |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1649 | DQUOT_FREE_BLOCK(inode, *count-num); |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1650 | *count = num; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1651 | return ret_block; |
| 1652 | |
| 1653 | io_error: |
| 1654 | *errp = -EIO; |
| 1655 | out: |
| 1656 | if (fatal) { |
| 1657 | *errp = fatal; |
| 1658 | ext3_std_error(sb, fatal); |
| 1659 | } |
| 1660 | /* |
| 1661 | * Undo the block allocation |
| 1662 | */ |
| 1663 | if (!performed_allocation) |
Mingming Cao | faa5697 | 2006-03-26 01:37:58 -0800 | [diff] [blame] | 1664 | DQUOT_FREE_BLOCK(inode, *count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | brelse(bitmap_bh); |
| 1666 | return 0; |
| 1667 | } |
| 1668 | |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1669 | ext3_fsblk_t ext3_new_block(handle_t *handle, struct inode *inode, |
| 1670 | ext3_fsblk_t goal, int *errp) |
Mingming Cao | b54e41e | 2006-03-26 01:37:57 -0800 | [diff] [blame] | 1671 | { |
| 1672 | unsigned long count = 1; |
| 1673 | |
| 1674 | return ext3_new_blocks(handle, inode, goal, &count, errp); |
| 1675 | } |
| 1676 | |
Mingming Cao | 36faadc14 | 2006-09-27 01:49:32 -0700 | [diff] [blame] | 1677 | /** |
| 1678 | * ext3_count_free_blocks() -- count filesystem free blocks |
| 1679 | * @sb: superblock |
| 1680 | * |
| 1681 | * Adds up the number of free blocks from each block group. |
| 1682 | */ |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1683 | ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1684 | { |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1685 | ext3_fsblk_t desc_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1686 | struct ext3_group_desc *gdp; |
| 1687 | int i; |
Glauber de Oliveira Costa | 8bdac5d | 2005-09-22 21:44:26 -0700 | [diff] [blame] | 1688 | unsigned long ngroups = EXT3_SB(sb)->s_groups_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | #ifdef EXT3FS_DEBUG |
| 1690 | struct ext3_super_block *es; |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1691 | ext3_fsblk_t bitmap_count; |
| 1692 | unsigned long x; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1693 | struct buffer_head *bitmap_bh = NULL; |
| 1694 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1695 | es = EXT3_SB(sb)->s_es; |
| 1696 | desc_count = 0; |
| 1697 | bitmap_count = 0; |
| 1698 | gdp = NULL; |
Glauber de Oliveira Costa | 8bdac5d | 2005-09-22 21:44:26 -0700 | [diff] [blame] | 1699 | |
Glauber de Oliveira Costa | 5b11687 | 2005-10-30 15:02:48 -0800 | [diff] [blame] | 1700 | smp_rmb(); |
Glauber de Oliveira Costa | 8bdac5d | 2005-09-22 21:44:26 -0700 | [diff] [blame] | 1701 | for (i = 0; i < ngroups; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1702 | gdp = ext3_get_group_desc(sb, i, NULL); |
| 1703 | if (!gdp) |
| 1704 | continue; |
| 1705 | desc_count += le16_to_cpu(gdp->bg_free_blocks_count); |
| 1706 | brelse(bitmap_bh); |
| 1707 | bitmap_bh = read_block_bitmap(sb, i); |
| 1708 | if (bitmap_bh == NULL) |
| 1709 | continue; |
| 1710 | |
| 1711 | x = ext3_count_free(bitmap_bh, sb->s_blocksize); |
| 1712 | printk("group %d: stored = %d, counted = %lu\n", |
| 1713 | i, le16_to_cpu(gdp->bg_free_blocks_count), x); |
| 1714 | bitmap_count += x; |
| 1715 | } |
| 1716 | brelse(bitmap_bh); |
Mingming Cao | 43d23f9 | 2006-06-25 05:48:07 -0700 | [diff] [blame] | 1717 | printk("ext3_count_free_blocks: stored = "E3FSBLK |
| 1718 | ", computed = "E3FSBLK", "E3FSBLK"\n", |
| 1719 | le32_to_cpu(es->s_free_blocks_count), |
| 1720 | desc_count, bitmap_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | return bitmap_count; |
| 1722 | #else |
| 1723 | desc_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | smp_rmb(); |
| 1725 | for (i = 0; i < ngroups; i++) { |
| 1726 | gdp = ext3_get_group_desc(sb, i, NULL); |
| 1727 | if (!gdp) |
| 1728 | continue; |
| 1729 | desc_count += le16_to_cpu(gdp->bg_free_blocks_count); |
| 1730 | } |
| 1731 | |
| 1732 | return desc_count; |
| 1733 | #endif |
| 1734 | } |
| 1735 | |
| 1736 | static inline int |
Mingming Cao | 1c2bf37 | 2006-06-25 05:48:06 -0700 | [diff] [blame] | 1737 | block_in_use(ext3_fsblk_t block, struct super_block *sb, unsigned char *map) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1738 | { |
| 1739 | return ext3_test_bit ((block - |
| 1740 | le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) % |
| 1741 | EXT3_BLOCKS_PER_GROUP(sb), map); |
| 1742 | } |
| 1743 | |
| 1744 | static inline int test_root(int a, int b) |
| 1745 | { |
| 1746 | int num = b; |
| 1747 | |
| 1748 | while (a > num) |
| 1749 | num *= b; |
| 1750 | return num == a; |
| 1751 | } |
| 1752 | |
| 1753 | static int ext3_group_sparse(int group) |
| 1754 | { |
| 1755 | if (group <= 1) |
| 1756 | return 1; |
| 1757 | if (!(group & 1)) |
| 1758 | return 0; |
| 1759 | return (test_root(group, 7) || test_root(group, 5) || |
| 1760 | test_root(group, 3)); |
| 1761 | } |
| 1762 | |
| 1763 | /** |
| 1764 | * ext3_bg_has_super - number of blocks used by the superblock in group |
| 1765 | * @sb: superblock for filesystem |
| 1766 | * @group: group number to check |
| 1767 | * |
| 1768 | * Return the number of blocks used by the superblock (primary or backup) |
| 1769 | * in this group. Currently this will be only 0 or 1. |
| 1770 | */ |
| 1771 | int ext3_bg_has_super(struct super_block *sb, int group) |
| 1772 | { |
Glauber de Oliveira Costa | b5a7c4f | 2006-03-24 03:18:37 -0800 | [diff] [blame] | 1773 | if (EXT3_HAS_RO_COMPAT_FEATURE(sb, |
| 1774 | EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) && |
| 1775 | !ext3_group_sparse(group)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1776 | return 0; |
| 1777 | return 1; |
| 1778 | } |
| 1779 | |
Glauber de Oliveira Costa | b5a7c4f | 2006-03-24 03:18:37 -0800 | [diff] [blame] | 1780 | static unsigned long ext3_bg_num_gdb_meta(struct super_block *sb, int group) |
| 1781 | { |
| 1782 | unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb); |
| 1783 | unsigned long first = metagroup * EXT3_DESC_PER_BLOCK(sb); |
| 1784 | unsigned long last = first + EXT3_DESC_PER_BLOCK(sb) - 1; |
| 1785 | |
| 1786 | if (group == first || group == first + 1 || group == last) |
| 1787 | return 1; |
| 1788 | return 0; |
| 1789 | } |
| 1790 | |
| 1791 | static unsigned long ext3_bg_num_gdb_nometa(struct super_block *sb, int group) |
| 1792 | { |
| 1793 | if (EXT3_HAS_RO_COMPAT_FEATURE(sb, |
| 1794 | EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER) && |
| 1795 | !ext3_group_sparse(group)) |
| 1796 | return 0; |
| 1797 | return EXT3_SB(sb)->s_gdb_count; |
| 1798 | } |
| 1799 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1800 | /** |
| 1801 | * ext3_bg_num_gdb - number of blocks used by the group table in group |
| 1802 | * @sb: superblock for filesystem |
| 1803 | * @group: group number to check |
| 1804 | * |
| 1805 | * Return the number of blocks used by the group descriptor table |
| 1806 | * (primary or backup) in this group. In the future there may be a |
| 1807 | * different number of descriptor blocks in each group. |
| 1808 | */ |
| 1809 | unsigned long ext3_bg_num_gdb(struct super_block *sb, int group) |
| 1810 | { |
Glauber de Oliveira Costa | b5a7c4f | 2006-03-24 03:18:37 -0800 | [diff] [blame] | 1811 | unsigned long first_meta_bg = |
| 1812 | le32_to_cpu(EXT3_SB(sb)->s_es->s_first_meta_bg); |
| 1813 | unsigned long metagroup = group / EXT3_DESC_PER_BLOCK(sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1814 | |
Glauber de Oliveira Costa | b5a7c4f | 2006-03-24 03:18:37 -0800 | [diff] [blame] | 1815 | if (!EXT3_HAS_INCOMPAT_FEATURE(sb,EXT3_FEATURE_INCOMPAT_META_BG) || |
| 1816 | metagroup < first_meta_bg) |
| 1817 | return ext3_bg_num_gdb_nometa(sb,group); |
| 1818 | |
| 1819 | return ext3_bg_num_gdb_meta(sb,group); |
| 1820 | |
| 1821 | } |