Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/ext2/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 "ext2.h" |
| 15 | #include <linux/quotaops.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/sched.h> |
| 18 | #include <linux/buffer_head.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 19 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
| 21 | /* |
| 22 | * balloc.c contains the blocks allocation and deallocation routines |
| 23 | */ |
| 24 | |
| 25 | /* |
| 26 | * The free blocks are managed by bitmaps. A file system contains several |
| 27 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap |
| 28 | * block for inodes, N blocks for the inode table and data blocks. |
| 29 | * |
| 30 | * The file system contains group descriptors which are located after the |
| 31 | * super block. Each descriptor contains the number of the bitmap block and |
| 32 | * 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] | 33 | * when a file system is mounted (see ext2_fill_super). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | */ |
| 35 | |
| 36 | |
| 37 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) |
| 38 | |
| 39 | struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, |
| 40 | unsigned int block_group, |
| 41 | struct buffer_head ** bh) |
| 42 | { |
| 43 | unsigned long group_desc; |
| 44 | unsigned long offset; |
| 45 | struct ext2_group_desc * desc; |
| 46 | struct ext2_sb_info *sbi = EXT2_SB(sb); |
| 47 | |
| 48 | if (block_group >= sbi->s_groups_count) { |
| 49 | ext2_error (sb, "ext2_get_group_desc", |
| 50 | "block_group >= groups_count - " |
| 51 | "block_group = %d, groups_count = %lu", |
| 52 | block_group, sbi->s_groups_count); |
| 53 | |
| 54 | return NULL; |
| 55 | } |
| 56 | |
| 57 | group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb); |
| 58 | offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1); |
| 59 | if (!sbi->s_group_desc[group_desc]) { |
| 60 | ext2_error (sb, "ext2_get_group_desc", |
| 61 | "Group descriptor not loaded - " |
| 62 | "block_group = %d, group_desc = %lu, desc = %lu", |
| 63 | block_group, group_desc, offset); |
| 64 | return NULL; |
| 65 | } |
| 66 | |
| 67 | desc = (struct ext2_group_desc *) sbi->s_group_desc[group_desc]->b_data; |
| 68 | if (bh) |
| 69 | *bh = sbi->s_group_desc[group_desc]; |
| 70 | return desc + offset; |
| 71 | } |
| 72 | |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 73 | static int ext2_valid_block_bitmap(struct super_block *sb, |
| 74 | struct ext2_group_desc *desc, |
| 75 | unsigned int block_group, |
| 76 | struct buffer_head *bh) |
| 77 | { |
| 78 | ext2_grpblk_t offset; |
| 79 | ext2_grpblk_t next_zero_bit; |
| 80 | ext2_fsblk_t bitmap_blk; |
| 81 | ext2_fsblk_t group_first_block; |
| 82 | |
| 83 | group_first_block = ext2_group_first_block_no(sb, block_group); |
| 84 | |
| 85 | /* check whether block bitmap block number is set */ |
| 86 | bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); |
| 87 | offset = bitmap_blk - group_first_block; |
| 88 | if (!ext2_test_bit(offset, bh->b_data)) |
| 89 | /* bad block bitmap */ |
| 90 | goto err_out; |
| 91 | |
| 92 | /* check whether the inode bitmap block number is set */ |
| 93 | bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap); |
| 94 | offset = bitmap_blk - group_first_block; |
| 95 | if (!ext2_test_bit(offset, bh->b_data)) |
| 96 | /* bad block bitmap */ |
| 97 | goto err_out; |
| 98 | |
| 99 | /* check whether the inode table block number is set */ |
| 100 | bitmap_blk = le32_to_cpu(desc->bg_inode_table); |
| 101 | offset = bitmap_blk - group_first_block; |
| 102 | next_zero_bit = ext2_find_next_zero_bit(bh->b_data, |
| 103 | offset + EXT2_SB(sb)->s_itb_per_group, |
| 104 | offset); |
| 105 | if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group) |
| 106 | /* good bitmap for inode tables */ |
| 107 | return 1; |
| 108 | |
| 109 | err_out: |
Harvey Harrison | 605afd6 | 2008-04-28 02:16:03 -0700 | [diff] [blame] | 110 | ext2_error(sb, __func__, |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 111 | "Invalid block bitmap - " |
| 112 | "block_group = %d, block = %lu", |
| 113 | block_group, bitmap_blk); |
| 114 | return 0; |
| 115 | } |
| 116 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | /* |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 118 | * Read the bitmap for a given block_group,and validate the |
| 119 | * bits for block/inode/inode tables are set in the bitmaps |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | * |
| 121 | * Return buffer_head on success or NULL in case of failure. |
| 122 | */ |
| 123 | static struct buffer_head * |
| 124 | read_block_bitmap(struct super_block *sb, unsigned int block_group) |
| 125 | { |
| 126 | struct ext2_group_desc * desc; |
| 127 | struct buffer_head * bh = NULL; |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 128 | ext2_fsblk_t bitmap_blk; |
| 129 | |
| 130 | desc = ext2_get_group_desc(sb, block_group, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | if (!desc) |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 132 | return NULL; |
| 133 | bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); |
| 134 | bh = sb_getblk(sb, bitmap_blk); |
| 135 | if (unlikely(!bh)) { |
Harvey Harrison | 605afd6 | 2008-04-28 02:16:03 -0700 | [diff] [blame] | 136 | ext2_error(sb, __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | "Cannot read block bitmap - " |
| 138 | "block_group = %d, block_bitmap = %u", |
| 139 | block_group, le32_to_cpu(desc->bg_block_bitmap)); |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 140 | return NULL; |
| 141 | } |
| 142 | if (likely(bh_uptodate_or_lock(bh))) |
| 143 | return bh; |
| 144 | |
| 145 | if (bh_submit_read(bh) < 0) { |
| 146 | brelse(bh); |
Harvey Harrison | 605afd6 | 2008-04-28 02:16:03 -0700 | [diff] [blame] | 147 | ext2_error(sb, __func__, |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 148 | "Cannot read block bitmap - " |
| 149 | "block_group = %d, block_bitmap = %u", |
| 150 | block_group, le32_to_cpu(desc->bg_block_bitmap)); |
| 151 | return NULL; |
| 152 | } |
Aneesh Kumar K.V | 01584fa | 2008-02-06 01:40:08 -0800 | [diff] [blame] | 153 | |
Aneesh Kumar K.V | 8b91582 | 2008-04-28 02:16:04 -0700 | [diff] [blame] | 154 | ext2_valid_block_bitmap(sb, desc, block_group, bh); |
| 155 | /* |
| 156 | * file system mounted not to panic on error, continue with corrupt |
| 157 | * bitmap |
| 158 | */ |
Linus Torvalds | 0b832a4 | 2007-11-13 08:07:31 -0800 | [diff] [blame] | 159 | return bh; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | } |
| 161 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 162 | static void group_adjust_blocks(struct super_block *sb, int group_no, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | struct ext2_group_desc *desc, struct buffer_head *bh, int count) |
| 164 | { |
| 165 | if (count) { |
| 166 | struct ext2_sb_info *sbi = EXT2_SB(sb); |
| 167 | unsigned free_blocks; |
| 168 | |
| 169 | spin_lock(sb_bgl_lock(sbi, group_no)); |
| 170 | free_blocks = le16_to_cpu(desc->bg_free_blocks_count); |
| 171 | desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count); |
| 172 | spin_unlock(sb_bgl_lock(sbi, group_no)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | mark_buffer_dirty(bh); |
| 174 | } |
| 175 | } |
| 176 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 177 | /* |
| 178 | * The reservation window structure operations |
| 179 | * -------------------------------------------- |
| 180 | * Operations include: |
| 181 | * dump, find, add, remove, is_empty, find_next_reservable_window, etc. |
| 182 | * |
| 183 | * We use a red-black tree to represent per-filesystem reservation |
| 184 | * windows. |
| 185 | * |
| 186 | */ |
| 187 | |
| 188 | /** |
| 189 | * __rsv_window_dump() -- Dump the filesystem block allocation reservation map |
| 190 | * @rb_root: root of per-filesystem reservation rb tree |
| 191 | * @verbose: verbose mode |
| 192 | * @fn: function which wishes to dump the reservation map |
| 193 | * |
| 194 | * If verbose is turned on, it will print the whole block reservation |
| 195 | * windows(start, end). Otherwise, it will only print out the "bad" windows, |
| 196 | * those windows that overlap with their immediate neighbors. |
| 197 | */ |
| 198 | #if 1 |
| 199 | static void __rsv_window_dump(struct rb_root *root, int verbose, |
| 200 | const char *fn) |
| 201 | { |
| 202 | struct rb_node *n; |
| 203 | struct ext2_reserve_window_node *rsv, *prev; |
| 204 | int bad; |
| 205 | |
| 206 | restart: |
| 207 | n = rb_first(root); |
| 208 | bad = 0; |
| 209 | prev = NULL; |
| 210 | |
| 211 | printk("Block Allocation Reservation Windows Map (%s):\n", fn); |
| 212 | while (n) { |
| 213 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); |
| 214 | if (verbose) |
| 215 | printk("reservation window 0x%p " |
| 216 | "start: %lu, end: %lu\n", |
| 217 | rsv, rsv->rsv_start, rsv->rsv_end); |
| 218 | if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { |
| 219 | printk("Bad reservation %p (start >= end)\n", |
| 220 | rsv); |
| 221 | bad = 1; |
| 222 | } |
| 223 | if (prev && prev->rsv_end >= rsv->rsv_start) { |
| 224 | printk("Bad reservation %p (prev->end >= start)\n", |
| 225 | rsv); |
| 226 | bad = 1; |
| 227 | } |
| 228 | if (bad) { |
| 229 | if (!verbose) { |
| 230 | printk("Restarting reservation walk in verbose mode\n"); |
| 231 | verbose = 1; |
| 232 | goto restart; |
| 233 | } |
| 234 | } |
| 235 | n = rb_next(n); |
| 236 | prev = rsv; |
| 237 | } |
| 238 | printk("Window map complete.\n"); |
Julia Lawall | 2c11619 | 2008-04-28 02:16:02 -0700 | [diff] [blame] | 239 | BUG_ON(bad); |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 240 | } |
| 241 | #define rsv_window_dump(root, verbose) \ |
Harvey Harrison | 605afd6 | 2008-04-28 02:16:03 -0700 | [diff] [blame] | 242 | __rsv_window_dump((root), (verbose), __func__) |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 243 | #else |
| 244 | #define rsv_window_dump(root, verbose) do {} while (0) |
| 245 | #endif |
| 246 | |
| 247 | /** |
| 248 | * goal_in_my_reservation() |
| 249 | * @rsv: inode's reservation window |
| 250 | * @grp_goal: given goal block relative to the allocation block group |
| 251 | * @group: the current allocation block group |
| 252 | * @sb: filesystem super block |
| 253 | * |
| 254 | * Test if the given goal block (group relative) is within the file's |
| 255 | * own block reservation window range. |
| 256 | * |
| 257 | * If the reservation window is outside the goal allocation group, return 0; |
| 258 | * grp_goal (given goal block) could be -1, which means no specific |
| 259 | * goal block. In this case, always return 1. |
| 260 | * If the goal block is within the reservation window, return 1; |
| 261 | * otherwise, return 0; |
| 262 | */ |
| 263 | static int |
| 264 | goal_in_my_reservation(struct ext2_reserve_window *rsv, ext2_grpblk_t grp_goal, |
| 265 | unsigned int group, struct super_block * sb) |
| 266 | { |
| 267 | ext2_fsblk_t group_first_block, group_last_block; |
| 268 | |
| 269 | group_first_block = ext2_group_first_block_no(sb, group); |
| 270 | group_last_block = group_first_block + EXT2_BLOCKS_PER_GROUP(sb) - 1; |
| 271 | |
| 272 | if ((rsv->_rsv_start > group_last_block) || |
| 273 | (rsv->_rsv_end < group_first_block)) |
| 274 | return 0; |
| 275 | if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start) |
| 276 | || (grp_goal + group_first_block > rsv->_rsv_end))) |
| 277 | return 0; |
| 278 | return 1; |
| 279 | } |
| 280 | |
| 281 | /** |
| 282 | * search_reserve_window() |
| 283 | * @rb_root: root of reservation tree |
| 284 | * @goal: target allocation block |
| 285 | * |
| 286 | * Find the reserved window which includes the goal, or the previous one |
| 287 | * if the goal is not in any window. |
| 288 | * Returns NULL if there are no windows or if all windows start after the goal. |
| 289 | */ |
| 290 | static struct ext2_reserve_window_node * |
| 291 | search_reserve_window(struct rb_root *root, ext2_fsblk_t goal) |
| 292 | { |
| 293 | struct rb_node *n = root->rb_node; |
| 294 | struct ext2_reserve_window_node *rsv; |
| 295 | |
| 296 | if (!n) |
| 297 | return NULL; |
| 298 | |
| 299 | do { |
| 300 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); |
| 301 | |
| 302 | if (goal < rsv->rsv_start) |
| 303 | n = n->rb_left; |
| 304 | else if (goal > rsv->rsv_end) |
| 305 | n = n->rb_right; |
| 306 | else |
| 307 | return rsv; |
| 308 | } while (n); |
| 309 | /* |
| 310 | * We've fallen off the end of the tree: the goal wasn't inside |
| 311 | * any particular node. OK, the previous node must be to one |
| 312 | * side of the interval containing the goal. If it's the RHS, |
| 313 | * we need to back up one. |
| 314 | */ |
| 315 | if (rsv->rsv_start > goal) { |
| 316 | n = rb_prev(&rsv->rsv_node); |
| 317 | rsv = rb_entry(n, struct ext2_reserve_window_node, rsv_node); |
| 318 | } |
| 319 | return rsv; |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * ext2_rsv_window_add() -- Insert a window to the block reservation rb tree. |
| 324 | * @sb: super block |
| 325 | * @rsv: reservation window to add |
| 326 | * |
| 327 | * Must be called with rsv_lock held. |
| 328 | */ |
| 329 | void ext2_rsv_window_add(struct super_block *sb, |
| 330 | struct ext2_reserve_window_node *rsv) |
| 331 | { |
| 332 | struct rb_root *root = &EXT2_SB(sb)->s_rsv_window_root; |
| 333 | struct rb_node *node = &rsv->rsv_node; |
| 334 | ext2_fsblk_t start = rsv->rsv_start; |
| 335 | |
| 336 | struct rb_node ** p = &root->rb_node; |
| 337 | struct rb_node * parent = NULL; |
| 338 | struct ext2_reserve_window_node *this; |
| 339 | |
| 340 | while (*p) |
| 341 | { |
| 342 | parent = *p; |
| 343 | this = rb_entry(parent, struct ext2_reserve_window_node, rsv_node); |
| 344 | |
| 345 | if (start < this->rsv_start) |
| 346 | p = &(*p)->rb_left; |
| 347 | else if (start > this->rsv_end) |
| 348 | p = &(*p)->rb_right; |
| 349 | else { |
| 350 | rsv_window_dump(root, 1); |
| 351 | BUG(); |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | rb_link_node(node, parent, p); |
| 356 | rb_insert_color(node, root); |
| 357 | } |
| 358 | |
| 359 | /** |
| 360 | * rsv_window_remove() -- unlink a window from the reservation rb tree |
| 361 | * @sb: super block |
| 362 | * @rsv: reservation window to remove |
| 363 | * |
| 364 | * Mark the block reservation window as not allocated, and unlink it |
| 365 | * from the filesystem reservation window rb tree. Must be called with |
| 366 | * rsv_lock held. |
| 367 | */ |
| 368 | static void rsv_window_remove(struct super_block *sb, |
| 369 | struct ext2_reserve_window_node *rsv) |
| 370 | { |
| 371 | rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; |
| 372 | rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; |
| 373 | rsv->rsv_alloc_hit = 0; |
| 374 | rb_erase(&rsv->rsv_node, &EXT2_SB(sb)->s_rsv_window_root); |
| 375 | } |
| 376 | |
| 377 | /* |
| 378 | * rsv_is_empty() -- Check if the reservation window is allocated. |
| 379 | * @rsv: given reservation window to check |
| 380 | * |
| 381 | * returns 1 if the end block is EXT2_RESERVE_WINDOW_NOT_ALLOCATED. |
| 382 | */ |
| 383 | static inline int rsv_is_empty(struct ext2_reserve_window *rsv) |
| 384 | { |
| 385 | /* a valid reservation end block could not be 0 */ |
| 386 | return (rsv->_rsv_end == EXT2_RESERVE_WINDOW_NOT_ALLOCATED); |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * ext2_init_block_alloc_info() |
| 391 | * @inode: file inode structure |
| 392 | * |
| 393 | * Allocate and initialize the reservation window structure, and |
| 394 | * link the window to the ext2 inode structure at last |
| 395 | * |
| 396 | * The reservation window structure is only dynamically allocated |
| 397 | * and linked to ext2 inode the first time the open file |
| 398 | * needs a new block. So, before every ext2_new_block(s) call, for |
| 399 | * regular files, we should check whether the reservation window |
| 400 | * structure exists or not. In the latter case, this function is called. |
| 401 | * Fail to do so will result in block reservation being turned off for that |
| 402 | * open file. |
| 403 | * |
| 404 | * This function is called from ext2_get_blocks_handle(), also called |
| 405 | * when setting the reservation window size through ioctl before the file |
| 406 | * is open for write (needs block allocation). |
| 407 | * |
| 408 | * Needs truncate_mutex protection prior to calling this function. |
| 409 | */ |
| 410 | void ext2_init_block_alloc_info(struct inode *inode) |
| 411 | { |
| 412 | struct ext2_inode_info *ei = EXT2_I(inode); |
Julia Lawall | 6e3d6ca0 | 2011-08-04 12:29:32 +0200 | [diff] [blame] | 413 | struct ext2_block_alloc_info *block_i; |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 414 | struct super_block *sb = inode->i_sb; |
| 415 | |
| 416 | block_i = kmalloc(sizeof(*block_i), GFP_NOFS); |
| 417 | if (block_i) { |
| 418 | struct ext2_reserve_window_node *rsv = &block_i->rsv_window_node; |
| 419 | |
| 420 | rsv->rsv_start = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; |
| 421 | rsv->rsv_end = EXT2_RESERVE_WINDOW_NOT_ALLOCATED; |
| 422 | |
| 423 | /* |
| 424 | * if filesystem is mounted with NORESERVATION, the goal |
| 425 | * reservation window size is set to zero to indicate |
| 426 | * block reservation is off |
| 427 | */ |
| 428 | if (!test_opt(sb, RESERVATION)) |
| 429 | rsv->rsv_goal_size = 0; |
| 430 | else |
| 431 | rsv->rsv_goal_size = EXT2_DEFAULT_RESERVE_BLOCKS; |
| 432 | rsv->rsv_alloc_hit = 0; |
| 433 | block_i->last_alloc_logical_block = 0; |
| 434 | block_i->last_alloc_physical_block = 0; |
| 435 | } |
| 436 | ei->i_block_alloc_info = block_i; |
| 437 | } |
| 438 | |
| 439 | /** |
| 440 | * ext2_discard_reservation() |
| 441 | * @inode: inode |
| 442 | * |
| 443 | * Discard(free) block reservation window on last file close, or truncate |
| 444 | * or at last iput(). |
| 445 | * |
| 446 | * It is being called in three cases: |
| 447 | * ext2_release_file(): last writer closes the file |
| 448 | * ext2_clear_inode(): last iput(), when nobody links to this file. |
| 449 | * ext2_truncate(): when the block indirect map is about to change. |
| 450 | */ |
| 451 | void ext2_discard_reservation(struct inode *inode) |
| 452 | { |
| 453 | struct ext2_inode_info *ei = EXT2_I(inode); |
| 454 | struct ext2_block_alloc_info *block_i = ei->i_block_alloc_info; |
| 455 | struct ext2_reserve_window_node *rsv; |
| 456 | spinlock_t *rsv_lock = &EXT2_SB(inode->i_sb)->s_rsv_window_lock; |
| 457 | |
| 458 | if (!block_i) |
| 459 | return; |
| 460 | |
| 461 | rsv = &block_i->rsv_window_node; |
| 462 | if (!rsv_is_empty(&rsv->rsv_window)) { |
| 463 | spin_lock(rsv_lock); |
| 464 | if (!rsv_is_empty(&rsv->rsv_window)) |
| 465 | rsv_window_remove(inode->i_sb, rsv); |
| 466 | spin_unlock(rsv_lock); |
| 467 | } |
| 468 | } |
| 469 | |
| 470 | /** |
Wang Sheng-Hui | 0324876 | 2012-05-18 15:04:45 +0800 | [diff] [blame] | 471 | * ext2_free_blocks() -- Free given blocks and update quota and i_blocks |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 472 | * @inode: inode |
Anatol Pomozov | 4907cb7 | 2012-09-01 10:31:09 -0700 | [diff] [blame] | 473 | * @block: start physical block to free |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 474 | * @count: number of blocks to free |
| 475 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | void ext2_free_blocks (struct inode * inode, unsigned long block, |
| 477 | unsigned long count) |
| 478 | { |
| 479 | struct buffer_head *bitmap_bh = NULL; |
| 480 | struct buffer_head * bh2; |
| 481 | unsigned long block_group; |
| 482 | unsigned long bit; |
| 483 | unsigned long i; |
| 484 | unsigned long overflow; |
| 485 | struct super_block * sb = inode->i_sb; |
| 486 | struct ext2_sb_info * sbi = EXT2_SB(sb); |
| 487 | struct ext2_group_desc * desc; |
| 488 | struct ext2_super_block * es = sbi->s_es; |
| 489 | unsigned freed = 0, group_freed; |
| 490 | |
| 491 | if (block < le32_to_cpu(es->s_first_data_block) || |
| 492 | block + count < block || |
| 493 | block + count > le32_to_cpu(es->s_blocks_count)) { |
| 494 | ext2_error (sb, "ext2_free_blocks", |
| 495 | "Freeing blocks not in datazone - " |
| 496 | "block = %lu, count = %lu", block, count); |
| 497 | goto error_return; |
| 498 | } |
| 499 | |
| 500 | ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); |
| 501 | |
| 502 | do_more: |
| 503 | overflow = 0; |
| 504 | block_group = (block - le32_to_cpu(es->s_first_data_block)) / |
| 505 | EXT2_BLOCKS_PER_GROUP(sb); |
| 506 | bit = (block - le32_to_cpu(es->s_first_data_block)) % |
| 507 | EXT2_BLOCKS_PER_GROUP(sb); |
| 508 | /* |
| 509 | * Check to see if we are freeing blocks across a group |
| 510 | * boundary. |
| 511 | */ |
| 512 | if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) { |
| 513 | overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb); |
| 514 | count -= overflow; |
| 515 | } |
| 516 | brelse(bitmap_bh); |
| 517 | bitmap_bh = read_block_bitmap(sb, block_group); |
| 518 | if (!bitmap_bh) |
| 519 | goto error_return; |
| 520 | |
| 521 | desc = ext2_get_group_desc (sb, block_group, &bh2); |
| 522 | if (!desc) |
| 523 | goto error_return; |
| 524 | |
| 525 | if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) || |
| 526 | in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) || |
| 527 | in_range (block, le32_to_cpu(desc->bg_inode_table), |
| 528 | sbi->s_itb_per_group) || |
| 529 | in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), |
Aneesh Kumar K.V | 7f0adae | 2008-02-06 01:36:17 -0800 | [diff] [blame] | 530 | sbi->s_itb_per_group)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | ext2_error (sb, "ext2_free_blocks", |
| 532 | "Freeing blocks in system zones - " |
| 533 | "Block = %lu, count = %lu", |
| 534 | block, count); |
Aneesh Kumar K.V | 7f0adae | 2008-02-06 01:36:17 -0800 | [diff] [blame] | 535 | goto error_return; |
| 536 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | |
| 538 | for (i = 0, group_freed = 0; i < count; i++) { |
| 539 | if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group), |
| 540 | bit + i, bitmap_bh->b_data)) { |
Harvey Harrison | 605afd6 | 2008-04-28 02:16:03 -0700 | [diff] [blame] | 541 | ext2_error(sb, __func__, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | "bit already cleared for block %lu", block + i); |
| 543 | } else { |
| 544 | group_freed++; |
| 545 | } |
| 546 | } |
| 547 | |
| 548 | mark_buffer_dirty(bitmap_bh); |
| 549 | if (sb->s_flags & MS_SYNCHRONOUS) |
| 550 | sync_dirty_buffer(bitmap_bh); |
| 551 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 552 | group_adjust_blocks(sb, block_group, desc, bh2, group_freed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 553 | freed += group_freed; |
| 554 | |
| 555 | if (overflow) { |
| 556 | block += count; |
| 557 | count = overflow; |
| 558 | goto do_more; |
| 559 | } |
| 560 | error_return: |
| 561 | brelse(bitmap_bh); |
Wang Shilong | 8e3dffc | 2013-02-07 22:57:53 +0800 | [diff] [blame] | 562 | if (freed) { |
Wang Shilong | 712ddc5 | 2013-02-07 22:57:54 +0800 | [diff] [blame] | 563 | percpu_counter_add(&sbi->s_freeblocks_counter, freed); |
Wang Shilong | 8e3dffc | 2013-02-07 22:57:53 +0800 | [diff] [blame] | 564 | dquot_free_block_nodirty(inode, freed); |
| 565 | mark_inode_dirty(inode); |
| 566 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | } |
| 568 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 569 | /** |
| 570 | * bitmap_search_next_usable_block() |
| 571 | * @start: the starting block (group relative) of the search |
| 572 | * @bh: bufferhead contains the block group bitmap |
| 573 | * @maxblocks: the ending block (group relative) of the reservation |
| 574 | * |
| 575 | * The bitmap search --- search forward through the actual bitmap on disk until |
| 576 | * we find a bit free. |
| 577 | */ |
| 578 | static ext2_grpblk_t |
| 579 | bitmap_search_next_usable_block(ext2_grpblk_t start, struct buffer_head *bh, |
| 580 | ext2_grpblk_t maxblocks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | { |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 582 | ext2_grpblk_t next; |
| 583 | |
| 584 | next = ext2_find_next_zero_bit(bh->b_data, maxblocks, start); |
| 585 | if (next >= maxblocks) |
| 586 | return -1; |
| 587 | return next; |
| 588 | } |
| 589 | |
| 590 | /** |
| 591 | * find_next_usable_block() |
| 592 | * @start: the starting block (group relative) to find next |
| 593 | * allocatable block in bitmap. |
| 594 | * @bh: bufferhead contains the block group bitmap |
| 595 | * @maxblocks: the ending block (group relative) for the search |
| 596 | * |
| 597 | * Find an allocatable block in a bitmap. We perform the "most |
| 598 | * appropriate allocation" algorithm of looking for a free block near |
| 599 | * the initial goal; then for a free byte somewhere in the bitmap; |
| 600 | * then for any free bit in the bitmap. |
| 601 | */ |
| 602 | static ext2_grpblk_t |
| 603 | find_next_usable_block(int start, struct buffer_head *bh, int maxblocks) |
| 604 | { |
| 605 | ext2_grpblk_t here, next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | char *p, *r; |
| 607 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 608 | if (start > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | /* |
| 610 | * The goal was occupied; search forward for a free |
| 611 | * block within the next XX blocks. |
| 612 | * |
| 613 | * end_goal is more or less random, but it has to be |
| 614 | * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the |
| 615 | * next 64-bit boundary is simple.. |
| 616 | */ |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 617 | ext2_grpblk_t end_goal = (start + 63) & ~63; |
| 618 | if (end_goal > maxblocks) |
| 619 | end_goal = maxblocks; |
| 620 | here = ext2_find_next_zero_bit(bh->b_data, end_goal, start); |
| 621 | if (here < end_goal) |
| 622 | return here; |
| 623 | ext2_debug("Bit not found near goal\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | } |
| 625 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 626 | here = start; |
| 627 | if (here < 0) |
| 628 | here = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 630 | p = ((char *)bh->b_data) + (here >> 3); |
| 631 | r = memscan(p, 0, ((maxblocks + 7) >> 3) - (here >> 3)); |
| 632 | next = (r - ((char *)bh->b_data)) << 3; |
| 633 | |
| 634 | if (next < maxblocks && next >= here) |
| 635 | return next; |
| 636 | |
| 637 | here = bitmap_search_next_usable_block(here, bh, maxblocks); |
| 638 | return here; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | } |
| 640 | |
Namhyung Kim | 26f78b7 | 2010-09-26 15:31:00 +0900 | [diff] [blame] | 641 | /** |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 642 | * ext2_try_to_allocate() |
| 643 | * @sb: superblock |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 644 | * @group: given allocation block group |
| 645 | * @bitmap_bh: bufferhead holds the block bitmap |
| 646 | * @grp_goal: given target block within the group |
| 647 | * @count: target number of blocks to allocate |
| 648 | * @my_rsv: reservation window |
| 649 | * |
| 650 | * Attempt to allocate blocks within a give range. Set the range of allocation |
| 651 | * first, then find the first free bit(s) from the bitmap (within the range), |
| 652 | * and at last, allocate the blocks by claiming the found free bit as allocated. |
| 653 | * |
| 654 | * To set the range of this allocation: |
| 655 | * if there is a reservation window, only try to allocate block(s) |
| 656 | * from the file's own reservation window; |
| 657 | * Otherwise, the allocation range starts from the give goal block, |
| 658 | * ends at the block group's last block. |
| 659 | * |
| 660 | * If we failed to allocate the desired block then we may end up crossing to a |
| 661 | * new bitmap. |
| 662 | */ |
| 663 | static int |
| 664 | ext2_try_to_allocate(struct super_block *sb, int group, |
| 665 | struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, |
| 666 | unsigned long *count, |
| 667 | struct ext2_reserve_window *my_rsv) |
| 668 | { |
| 669 | ext2_fsblk_t group_first_block; |
| 670 | ext2_grpblk_t start, end; |
| 671 | unsigned long num = 0; |
| 672 | |
| 673 | /* we do allocation within the reservation window if we have a window */ |
| 674 | if (my_rsv) { |
| 675 | group_first_block = ext2_group_first_block_no(sb, group); |
| 676 | if (my_rsv->_rsv_start >= group_first_block) |
| 677 | start = my_rsv->_rsv_start - group_first_block; |
| 678 | else |
| 679 | /* reservation window cross group boundary */ |
| 680 | start = 0; |
| 681 | end = my_rsv->_rsv_end - group_first_block + 1; |
| 682 | if (end > EXT2_BLOCKS_PER_GROUP(sb)) |
| 683 | /* reservation window crosses group boundary */ |
| 684 | end = EXT2_BLOCKS_PER_GROUP(sb); |
| 685 | if ((start <= grp_goal) && (grp_goal < end)) |
| 686 | start = grp_goal; |
| 687 | else |
| 688 | grp_goal = -1; |
| 689 | } else { |
| 690 | if (grp_goal > 0) |
| 691 | start = grp_goal; |
| 692 | else |
| 693 | start = 0; |
| 694 | end = EXT2_BLOCKS_PER_GROUP(sb); |
| 695 | } |
| 696 | |
| 697 | BUG_ON(start > EXT2_BLOCKS_PER_GROUP(sb)); |
| 698 | |
| 699 | repeat: |
| 700 | if (grp_goal < 0) { |
| 701 | grp_goal = find_next_usable_block(start, bitmap_bh, end); |
| 702 | if (grp_goal < 0) |
| 703 | goto fail_access; |
| 704 | if (!my_rsv) { |
| 705 | int i; |
| 706 | |
| 707 | for (i = 0; i < 7 && grp_goal > start && |
| 708 | !ext2_test_bit(grp_goal - 1, |
| 709 | bitmap_bh->b_data); |
| 710 | i++, grp_goal--) |
| 711 | ; |
| 712 | } |
| 713 | } |
| 714 | start = grp_goal; |
| 715 | |
| 716 | if (ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), grp_goal, |
| 717 | bitmap_bh->b_data)) { |
| 718 | /* |
| 719 | * The block was allocated by another thread, or it was |
| 720 | * allocated and then freed by another thread |
| 721 | */ |
| 722 | start++; |
| 723 | grp_goal++; |
| 724 | if (start >= end) |
| 725 | goto fail_access; |
| 726 | goto repeat; |
| 727 | } |
| 728 | num++; |
| 729 | grp_goal++; |
| 730 | while (num < *count && grp_goal < end |
| 731 | && !ext2_set_bit_atomic(sb_bgl_lock(EXT2_SB(sb), group), |
| 732 | grp_goal, bitmap_bh->b_data)) { |
| 733 | num++; |
| 734 | grp_goal++; |
| 735 | } |
| 736 | *count = num; |
| 737 | return grp_goal - num; |
| 738 | fail_access: |
| 739 | *count = num; |
| 740 | return -1; |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * find_next_reservable_window(): |
| 745 | * find a reservable space within the given range. |
| 746 | * It does not allocate the reservation window for now: |
| 747 | * alloc_new_reservation() will do the work later. |
| 748 | * |
| 749 | * @search_head: the head of the searching list; |
| 750 | * This is not necessarily the list head of the whole filesystem |
| 751 | * |
| 752 | * We have both head and start_block to assist the search |
| 753 | * for the reservable space. The list starts from head, |
| 754 | * but we will shift to the place where start_block is, |
| 755 | * then start from there, when looking for a reservable space. |
| 756 | * |
| 757 | * @size: the target new reservation window size |
| 758 | * |
| 759 | * @group_first_block: the first block we consider to start |
| 760 | * the real search from |
| 761 | * |
| 762 | * @last_block: |
| 763 | * the maximum block number that our goal reservable space |
| 764 | * could start from. This is normally the last block in this |
| 765 | * group. The search will end when we found the start of next |
| 766 | * possible reservable space is out of this boundary. |
| 767 | * This could handle the cross boundary reservation window |
| 768 | * request. |
| 769 | * |
| 770 | * basically we search from the given range, rather than the whole |
| 771 | * reservation double linked list, (start_block, last_block) |
| 772 | * to find a free region that is of my size and has not |
| 773 | * been reserved. |
| 774 | * |
| 775 | */ |
| 776 | static int find_next_reservable_window( |
| 777 | struct ext2_reserve_window_node *search_head, |
| 778 | struct ext2_reserve_window_node *my_rsv, |
| 779 | struct super_block * sb, |
| 780 | ext2_fsblk_t start_block, |
| 781 | ext2_fsblk_t last_block) |
| 782 | { |
| 783 | struct rb_node *next; |
| 784 | struct ext2_reserve_window_node *rsv, *prev; |
| 785 | ext2_fsblk_t cur; |
| 786 | int size = my_rsv->rsv_goal_size; |
| 787 | |
| 788 | /* TODO: make the start of the reservation window byte-aligned */ |
| 789 | /* cur = *start_block & ~7;*/ |
| 790 | cur = start_block; |
| 791 | rsv = search_head; |
| 792 | if (!rsv) |
| 793 | return -1; |
| 794 | |
| 795 | while (1) { |
| 796 | if (cur <= rsv->rsv_end) |
| 797 | cur = rsv->rsv_end + 1; |
| 798 | |
| 799 | /* TODO? |
| 800 | * in the case we could not find a reservable space |
| 801 | * that is what is expected, during the re-search, we could |
| 802 | * remember what's the largest reservable space we could have |
| 803 | * and return that one. |
| 804 | * |
| 805 | * For now it will fail if we could not find the reservable |
| 806 | * space with expected-size (or more)... |
| 807 | */ |
| 808 | if (cur > last_block) |
| 809 | return -1; /* fail */ |
| 810 | |
| 811 | prev = rsv; |
| 812 | next = rb_next(&rsv->rsv_node); |
| 813 | rsv = rb_entry(next,struct ext2_reserve_window_node,rsv_node); |
| 814 | |
| 815 | /* |
| 816 | * Reached the last reservation, we can just append to the |
| 817 | * previous one. |
| 818 | */ |
| 819 | if (!next) |
| 820 | break; |
| 821 | |
| 822 | if (cur + size <= rsv->rsv_start) { |
| 823 | /* |
| 824 | * Found a reserveable space big enough. We could |
| 825 | * have a reservation across the group boundary here |
| 826 | */ |
| 827 | break; |
| 828 | } |
| 829 | } |
| 830 | /* |
| 831 | * we come here either : |
| 832 | * when we reach the end of the whole list, |
| 833 | * and there is empty reservable space after last entry in the list. |
| 834 | * append it to the end of the list. |
| 835 | * |
| 836 | * or we found one reservable space in the middle of the list, |
| 837 | * return the reservation window that we could append to. |
| 838 | * succeed. |
| 839 | */ |
| 840 | |
| 841 | if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) |
| 842 | rsv_window_remove(sb, my_rsv); |
| 843 | |
| 844 | /* |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 845 | * Let's book the whole available window for now. We will check the |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 846 | * disk bitmap later and then, if there are free blocks then we adjust |
| 847 | * the window size if it's larger than requested. |
| 848 | * Otherwise, we will remove this node from the tree next time |
| 849 | * call find_next_reservable_window. |
| 850 | */ |
| 851 | my_rsv->rsv_start = cur; |
| 852 | my_rsv->rsv_end = cur + size - 1; |
| 853 | my_rsv->rsv_alloc_hit = 0; |
| 854 | |
| 855 | if (prev != my_rsv) |
| 856 | ext2_rsv_window_add(sb, my_rsv); |
| 857 | |
| 858 | return 0; |
| 859 | } |
| 860 | |
| 861 | /** |
| 862 | * alloc_new_reservation()--allocate a new reservation window |
| 863 | * |
| 864 | * To make a new reservation, we search part of the filesystem |
| 865 | * reservation list (the list that inside the group). We try to |
| 866 | * allocate a new reservation window near the allocation goal, |
| 867 | * or the beginning of the group, if there is no goal. |
| 868 | * |
| 869 | * We first find a reservable space after the goal, then from |
| 870 | * there, we check the bitmap for the first free block after |
| 871 | * it. If there is no free block until the end of group, then the |
| 872 | * whole group is full, we failed. Otherwise, check if the free |
| 873 | * block is inside the expected reservable space, if so, we |
| 874 | * succeed. |
| 875 | * If the first free block is outside the reservable space, then |
| 876 | * start from the first free block, we search for next available |
| 877 | * space, and go on. |
| 878 | * |
| 879 | * on succeed, a new reservation will be found and inserted into the list |
| 880 | * It contains at least one free block, and it does not overlap with other |
| 881 | * reservation windows. |
| 882 | * |
| 883 | * failed: we failed to find a reservation window in this group |
| 884 | * |
| 885 | * @rsv: the reservation |
| 886 | * |
| 887 | * @grp_goal: The goal (group-relative). It is where the search for a |
| 888 | * free reservable space should start from. |
| 889 | * if we have a goal(goal >0 ), then start from there, |
| 890 | * no goal(goal = -1), we start from the first block |
| 891 | * of the group. |
| 892 | * |
| 893 | * @sb: the super block |
| 894 | * @group: the group we are trying to allocate in |
| 895 | * @bitmap_bh: the block group block bitmap |
| 896 | * |
| 897 | */ |
| 898 | static int alloc_new_reservation(struct ext2_reserve_window_node *my_rsv, |
| 899 | ext2_grpblk_t grp_goal, struct super_block *sb, |
| 900 | unsigned int group, struct buffer_head *bitmap_bh) |
| 901 | { |
| 902 | struct ext2_reserve_window_node *search_head; |
| 903 | ext2_fsblk_t group_first_block, group_end_block, start_block; |
| 904 | ext2_grpblk_t first_free_block; |
| 905 | struct rb_root *fs_rsv_root = &EXT2_SB(sb)->s_rsv_window_root; |
| 906 | unsigned long size; |
| 907 | int ret; |
| 908 | spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock; |
| 909 | |
| 910 | group_first_block = ext2_group_first_block_no(sb, group); |
| 911 | group_end_block = group_first_block + (EXT2_BLOCKS_PER_GROUP(sb) - 1); |
| 912 | |
| 913 | if (grp_goal < 0) |
| 914 | start_block = group_first_block; |
| 915 | else |
| 916 | start_block = grp_goal + group_first_block; |
| 917 | |
| 918 | size = my_rsv->rsv_goal_size; |
| 919 | |
| 920 | if (!rsv_is_empty(&my_rsv->rsv_window)) { |
| 921 | /* |
| 922 | * if the old reservation is cross group boundary |
| 923 | * and if the goal is inside the old reservation window, |
| 924 | * we will come here when we just failed to allocate from |
| 925 | * the first part of the window. We still have another part |
| 926 | * that belongs to the next group. In this case, there is no |
| 927 | * point to discard our window and try to allocate a new one |
| 928 | * in this group(which will fail). we should |
| 929 | * keep the reservation window, just simply move on. |
| 930 | * |
| 931 | * Maybe we could shift the start block of the reservation |
| 932 | * window to the first block of next group. |
| 933 | */ |
| 934 | |
| 935 | if ((my_rsv->rsv_start <= group_end_block) && |
| 936 | (my_rsv->rsv_end > group_end_block) && |
| 937 | (start_block >= my_rsv->rsv_start)) |
| 938 | return -1; |
| 939 | |
| 940 | if ((my_rsv->rsv_alloc_hit > |
| 941 | (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { |
| 942 | /* |
| 943 | * if the previously allocation hit ratio is |
| 944 | * greater than 1/2, then we double the size of |
| 945 | * the reservation window the next time, |
| 946 | * otherwise we keep the same size window |
| 947 | */ |
| 948 | size = size * 2; |
| 949 | if (size > EXT2_MAX_RESERVE_BLOCKS) |
| 950 | size = EXT2_MAX_RESERVE_BLOCKS; |
| 951 | my_rsv->rsv_goal_size= size; |
| 952 | } |
| 953 | } |
| 954 | |
| 955 | spin_lock(rsv_lock); |
| 956 | /* |
| 957 | * shift the search start to the window near the goal block |
| 958 | */ |
| 959 | search_head = search_reserve_window(fs_rsv_root, start_block); |
| 960 | |
| 961 | /* |
| 962 | * find_next_reservable_window() simply finds a reservable window |
| 963 | * inside the given range(start_block, group_end_block). |
| 964 | * |
| 965 | * To make sure the reservation window has a free bit inside it, we |
| 966 | * need to check the bitmap after we found a reservable window. |
| 967 | */ |
| 968 | retry: |
| 969 | ret = find_next_reservable_window(search_head, my_rsv, sb, |
| 970 | start_block, group_end_block); |
| 971 | |
| 972 | if (ret == -1) { |
| 973 | if (!rsv_is_empty(&my_rsv->rsv_window)) |
| 974 | rsv_window_remove(sb, my_rsv); |
| 975 | spin_unlock(rsv_lock); |
| 976 | return -1; |
| 977 | } |
| 978 | |
| 979 | /* |
| 980 | * On success, find_next_reservable_window() returns the |
| 981 | * reservation window where there is a reservable space after it. |
| 982 | * Before we reserve this reservable space, we need |
| 983 | * to make sure there is at least a free block inside this region. |
| 984 | * |
| 985 | * Search the first free bit on the block bitmap. Search starts from |
| 986 | * the start block of the reservable space we just found. |
| 987 | */ |
| 988 | spin_unlock(rsv_lock); |
| 989 | first_free_block = bitmap_search_next_usable_block( |
| 990 | my_rsv->rsv_start - group_first_block, |
| 991 | bitmap_bh, group_end_block - group_first_block + 1); |
| 992 | |
| 993 | if (first_free_block < 0) { |
| 994 | /* |
| 995 | * no free block left on the bitmap, no point |
| 996 | * to reserve the space. return failed. |
| 997 | */ |
| 998 | spin_lock(rsv_lock); |
| 999 | if (!rsv_is_empty(&my_rsv->rsv_window)) |
| 1000 | rsv_window_remove(sb, my_rsv); |
| 1001 | spin_unlock(rsv_lock); |
| 1002 | return -1; /* failed */ |
| 1003 | } |
| 1004 | |
| 1005 | start_block = first_free_block + group_first_block; |
| 1006 | /* |
| 1007 | * check if the first free block is within the |
| 1008 | * free space we just reserved |
| 1009 | */ |
| 1010 | if (start_block >= my_rsv->rsv_start && start_block <= my_rsv->rsv_end) |
| 1011 | return 0; /* success */ |
| 1012 | /* |
| 1013 | * if the first free bit we found is out of the reservable space |
| 1014 | * continue search for next reservable space, |
| 1015 | * start from where the free block is, |
| 1016 | * we also shift the list head to where we stopped last time |
| 1017 | */ |
| 1018 | search_head = my_rsv; |
| 1019 | spin_lock(rsv_lock); |
| 1020 | goto retry; |
| 1021 | } |
| 1022 | |
| 1023 | /** |
| 1024 | * try_to_extend_reservation() |
| 1025 | * @my_rsv: given reservation window |
| 1026 | * @sb: super block |
| 1027 | * @size: the delta to extend |
| 1028 | * |
| 1029 | * Attempt to expand the reservation window large enough to have |
| 1030 | * required number of free blocks |
| 1031 | * |
| 1032 | * Since ext2_try_to_allocate() will always allocate blocks within |
| 1033 | * the reservation window range, if the window size is too small, |
| 1034 | * multiple blocks allocation has to stop at the end of the reservation |
| 1035 | * window. To make this more efficient, given the total number of |
| 1036 | * blocks needed and the current size of the window, we try to |
| 1037 | * expand the reservation window size if necessary on a best-effort |
| 1038 | * basis before ext2_new_blocks() tries to allocate blocks. |
| 1039 | */ |
| 1040 | static void try_to_extend_reservation(struct ext2_reserve_window_node *my_rsv, |
| 1041 | struct super_block *sb, int size) |
| 1042 | { |
| 1043 | struct ext2_reserve_window_node *next_rsv; |
| 1044 | struct rb_node *next; |
| 1045 | spinlock_t *rsv_lock = &EXT2_SB(sb)->s_rsv_window_lock; |
| 1046 | |
| 1047 | if (!spin_trylock(rsv_lock)) |
| 1048 | return; |
| 1049 | |
| 1050 | next = rb_next(&my_rsv->rsv_node); |
| 1051 | |
| 1052 | if (!next) |
| 1053 | my_rsv->rsv_end += size; |
| 1054 | else { |
| 1055 | next_rsv = rb_entry(next, struct ext2_reserve_window_node, rsv_node); |
| 1056 | |
| 1057 | if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) |
| 1058 | my_rsv->rsv_end += size; |
| 1059 | else |
| 1060 | my_rsv->rsv_end = next_rsv->rsv_start - 1; |
| 1061 | } |
| 1062 | spin_unlock(rsv_lock); |
| 1063 | } |
| 1064 | |
| 1065 | /** |
| 1066 | * ext2_try_to_allocate_with_rsv() |
| 1067 | * @sb: superblock |
| 1068 | * @group: given allocation block group |
| 1069 | * @bitmap_bh: bufferhead holds the block bitmap |
| 1070 | * @grp_goal: given target block within the group |
| 1071 | * @count: target number of blocks to allocate |
| 1072 | * @my_rsv: reservation window |
| 1073 | * |
| 1074 | * This is the main function used to allocate a new block and its reservation |
| 1075 | * window. |
| 1076 | * |
| 1077 | * Each time when a new block allocation is need, first try to allocate from |
| 1078 | * its own reservation. If it does not have a reservation window, instead of |
| 1079 | * looking for a free bit on bitmap first, then look up the reservation list to |
| 1080 | * see if it is inside somebody else's reservation window, we try to allocate a |
| 1081 | * reservation window for it starting from the goal first. Then do the block |
| 1082 | * allocation within the reservation window. |
| 1083 | * |
| 1084 | * This will avoid keeping on searching the reservation list again and |
| 1085 | * again when somebody is looking for a free block (without |
| 1086 | * reservation), and there are lots of free blocks, but they are all |
| 1087 | * being reserved. |
| 1088 | * |
| 1089 | * We use a red-black tree for the per-filesystem reservation list. |
| 1090 | */ |
| 1091 | static ext2_grpblk_t |
| 1092 | ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group, |
| 1093 | struct buffer_head *bitmap_bh, ext2_grpblk_t grp_goal, |
| 1094 | struct ext2_reserve_window_node * my_rsv, |
| 1095 | unsigned long *count) |
| 1096 | { |
| 1097 | ext2_fsblk_t group_first_block, group_last_block; |
| 1098 | ext2_grpblk_t ret = 0; |
| 1099 | unsigned long num = *count; |
| 1100 | |
| 1101 | /* |
| 1102 | * we don't deal with reservation when |
| 1103 | * filesystem is mounted without reservation |
| 1104 | * or the file is not a regular file |
| 1105 | * or last attempt to allocate a block with reservation turned on failed |
| 1106 | */ |
| 1107 | if (my_rsv == NULL) { |
| 1108 | return ext2_try_to_allocate(sb, group, bitmap_bh, |
| 1109 | grp_goal, count, NULL); |
| 1110 | } |
| 1111 | /* |
| 1112 | * grp_goal is a group relative block number (if there is a goal) |
| 1113 | * 0 <= grp_goal < EXT2_BLOCKS_PER_GROUP(sb) |
| 1114 | * first block is a filesystem wide block number |
| 1115 | * first block is the block number of the first block in this group |
| 1116 | */ |
| 1117 | group_first_block = ext2_group_first_block_no(sb, group); |
| 1118 | group_last_block = group_first_block + (EXT2_BLOCKS_PER_GROUP(sb) - 1); |
| 1119 | |
| 1120 | /* |
| 1121 | * Basically we will allocate a new block from inode's reservation |
| 1122 | * window. |
| 1123 | * |
| 1124 | * We need to allocate a new reservation window, if: |
| 1125 | * a) inode does not have a reservation window; or |
| 1126 | * b) last attempt to allocate a block from existing reservation |
| 1127 | * failed; or |
| 1128 | * c) we come here with a goal and with a reservation window |
| 1129 | * |
| 1130 | * We do not need to allocate a new reservation window if we come here |
| 1131 | * at the beginning with a goal and the goal is inside the window, or |
| 1132 | * we don't have a goal but already have a reservation window. |
| 1133 | * then we could go to allocate from the reservation window directly. |
| 1134 | */ |
| 1135 | while (1) { |
| 1136 | if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || |
| 1137 | !goal_in_my_reservation(&my_rsv->rsv_window, |
| 1138 | grp_goal, group, sb)) { |
| 1139 | if (my_rsv->rsv_goal_size < *count) |
| 1140 | my_rsv->rsv_goal_size = *count; |
| 1141 | ret = alloc_new_reservation(my_rsv, grp_goal, sb, |
| 1142 | group, bitmap_bh); |
| 1143 | if (ret < 0) |
| 1144 | break; /* failed */ |
| 1145 | |
| 1146 | if (!goal_in_my_reservation(&my_rsv->rsv_window, |
| 1147 | grp_goal, group, sb)) |
| 1148 | grp_goal = -1; |
| 1149 | } else if (grp_goal >= 0) { |
| 1150 | int curr = my_rsv->rsv_end - |
| 1151 | (grp_goal + group_first_block) + 1; |
| 1152 | |
| 1153 | if (curr < *count) |
| 1154 | try_to_extend_reservation(my_rsv, sb, |
| 1155 | *count - curr); |
| 1156 | } |
| 1157 | |
| 1158 | if ((my_rsv->rsv_start > group_last_block) || |
| 1159 | (my_rsv->rsv_end < group_first_block)) { |
| 1160 | rsv_window_dump(&EXT2_SB(sb)->s_rsv_window_root, 1); |
| 1161 | BUG(); |
| 1162 | } |
| 1163 | ret = ext2_try_to_allocate(sb, group, bitmap_bh, grp_goal, |
| 1164 | &num, &my_rsv->rsv_window); |
| 1165 | if (ret >= 0) { |
| 1166 | my_rsv->rsv_alloc_hit += num; |
| 1167 | *count = num; |
| 1168 | break; /* succeed */ |
| 1169 | } |
| 1170 | num = *count; |
| 1171 | } |
| 1172 | return ret; |
| 1173 | } |
| 1174 | |
| 1175 | /** |
| 1176 | * ext2_has_free_blocks() |
| 1177 | * @sbi: in-core super block structure. |
| 1178 | * |
| 1179 | * Check if filesystem has at least 1 free block available for allocation. |
| 1180 | */ |
| 1181 | static int ext2_has_free_blocks(struct ext2_sb_info *sbi) |
| 1182 | { |
| 1183 | ext2_fsblk_t free_blocks, root_blocks; |
| 1184 | |
| 1185 | free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); |
| 1186 | root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count); |
| 1187 | if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && |
Eric W. Biederman | b8a9f9e | 2012-02-07 15:39:12 -0800 | [diff] [blame] | 1188 | !uid_eq(sbi->s_resuid, current_fsuid()) && |
| 1189 | (gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) || |
| 1190 | !in_group_p (sbi->s_resgid))) { |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1191 | return 0; |
| 1192 | } |
| 1193 | return 1; |
| 1194 | } |
| 1195 | |
| 1196 | /* |
Carlos Maiolino | ff0031d | 2016-07-05 22:02:41 -0400 | [diff] [blame] | 1197 | * Returns 1 if the passed-in block region is valid; 0 if some part overlaps |
| 1198 | * with filesystem metadata blocksi. |
| 1199 | */ |
| 1200 | int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, |
| 1201 | unsigned int count) |
| 1202 | { |
| 1203 | if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || |
| 1204 | (start_blk + count < start_blk) || |
| 1205 | (start_blk > le32_to_cpu(sbi->s_es->s_blocks_count))) |
| 1206 | return 0; |
| 1207 | |
| 1208 | /* Ensure we do not step over superblock */ |
| 1209 | if ((start_blk <= sbi->s_sb_block) && |
| 1210 | (start_blk + count >= sbi->s_sb_block)) |
| 1211 | return 0; |
| 1212 | |
| 1213 | |
| 1214 | return 1; |
| 1215 | } |
| 1216 | |
| 1217 | /* |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1218 | * ext2_new_blocks() -- core block(s) allocation function |
| 1219 | * @inode: file inode |
| 1220 | * @goal: given target block(filesystem wide) |
| 1221 | * @count: target number of blocks to allocate |
| 1222 | * @errp: error code |
| 1223 | * |
| 1224 | * ext2_new_blocks uses a goal block to assist allocation. If the goal is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1225 | * free, or there is a free block within 32 blocks of the goal, that block |
| 1226 | * is allocated. Otherwise a forward search is made for a free block; within |
| 1227 | * each block group the search first looks for an entire free byte in the block |
| 1228 | * bitmap, and then for any free bit if that fails. |
| 1229 | * This function also updates quota and i_blocks field. |
| 1230 | */ |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1231 | ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, |
| 1232 | unsigned long *count, int *errp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | { |
| 1234 | struct buffer_head *bitmap_bh = NULL; |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1235 | struct buffer_head *gdp_bh; |
| 1236 | int group_no; |
| 1237 | int goal_group; |
| 1238 | ext2_grpblk_t grp_target_blk; /* blockgroup relative goal block */ |
| 1239 | ext2_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ |
| 1240 | ext2_fsblk_t ret_block; /* filesyetem-wide allocated block */ |
| 1241 | int bgi; /* blockgroup iteration index */ |
| 1242 | int performed_allocation = 0; |
| 1243 | ext2_grpblk_t free_blocks; /* number of free blocks in a group */ |
| 1244 | struct super_block *sb; |
| 1245 | struct ext2_group_desc *gdp; |
| 1246 | struct ext2_super_block *es; |
| 1247 | struct ext2_sb_info *sbi; |
| 1248 | struct ext2_reserve_window_node *my_rsv = NULL; |
| 1249 | struct ext2_block_alloc_info *block_i; |
| 1250 | unsigned short windowsz = 0; |
| 1251 | unsigned long ngroups; |
| 1252 | unsigned long num = *count; |
Christoph Hellwig | 5dd4056 | 2010-03-03 09:05:00 -0500 | [diff] [blame] | 1253 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1254 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1255 | *errp = -ENOSPC; |
| 1256 | sb = inode->i_sb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1257 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1258 | /* |
| 1259 | * Check quota for allocation of this block. |
| 1260 | */ |
Christoph Hellwig | 5dd4056 | 2010-03-03 09:05:00 -0500 | [diff] [blame] | 1261 | ret = dquot_alloc_block(inode, num); |
| 1262 | if (ret) { |
| 1263 | *errp = ret; |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1264 | return 0; |
| 1265 | } |
| 1266 | |
| 1267 | sbi = EXT2_SB(sb); |
| 1268 | es = EXT2_SB(sb)->s_es; |
| 1269 | ext2_debug("goal=%lu.\n", goal); |
| 1270 | /* |
| 1271 | * Allocate a block from reservation only when |
| 1272 | * filesystem is mounted with reservation(default,-o reservation), and |
| 1273 | * it's a regular file, and |
| 1274 | * the desired window size is greater than 0 (One could use ioctl |
| 1275 | * command EXT2_IOC_SETRSVSZ to set the window size to 0 to turn off |
| 1276 | * reservation on that particular file) |
| 1277 | */ |
| 1278 | block_i = EXT2_I(inode)->i_block_alloc_info; |
| 1279 | if (block_i) { |
| 1280 | windowsz = block_i->rsv_window_node.rsv_goal_size; |
| 1281 | if (windowsz > 0) |
| 1282 | my_rsv = &block_i->rsv_window_node; |
| 1283 | } |
| 1284 | |
| 1285 | if (!ext2_has_free_blocks(sbi)) { |
| 1286 | *errp = -ENOSPC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | goto out; |
| 1288 | } |
| 1289 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1290 | /* |
| 1291 | * First, test whether the goal block is free. |
| 1292 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | if (goal < le32_to_cpu(es->s_first_data_block) || |
| 1294 | goal >= le32_to_cpu(es->s_blocks_count)) |
| 1295 | goal = le32_to_cpu(es->s_first_data_block); |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1296 | group_no = (goal - le32_to_cpu(es->s_first_data_block)) / |
| 1297 | EXT2_BLOCKS_PER_GROUP(sb); |
| 1298 | goal_group = group_no; |
| 1299 | retry_alloc: |
| 1300 | gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); |
| 1301 | if (!gdp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | goto io_error; |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1303 | |
| 1304 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
| 1305 | /* |
| 1306 | * if there is not enough free blocks to make a new resevation |
| 1307 | * turn off reservation for this allocation |
| 1308 | */ |
| 1309 | if (my_rsv && (free_blocks < windowsz) |
Mingming Cao | d707d31 | 2008-10-15 22:04:01 -0700 | [diff] [blame] | 1310 | && (free_blocks > 0) |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1311 | && (rsv_is_empty(&my_rsv->rsv_window))) |
| 1312 | my_rsv = NULL; |
| 1313 | |
| 1314 | if (free_blocks > 0) { |
| 1315 | grp_target_blk = ((goal - le32_to_cpu(es->s_first_data_block)) % |
| 1316 | EXT2_BLOCKS_PER_GROUP(sb)); |
| 1317 | bitmap_bh = read_block_bitmap(sb, group_no); |
| 1318 | if (!bitmap_bh) |
| 1319 | goto io_error; |
| 1320 | grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, |
| 1321 | bitmap_bh, grp_target_blk, |
| 1322 | my_rsv, &num); |
| 1323 | if (grp_alloc_blk >= 0) |
| 1324 | goto allocated; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | } |
| 1326 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1327 | ngroups = EXT2_SB(sb)->s_groups_count; |
| 1328 | smp_rmb(); |
| 1329 | |
| 1330 | /* |
Akinobu Mita | 144704e | 2008-02-06 01:40:15 -0800 | [diff] [blame] | 1331 | * Now search the rest of the groups. We assume that |
| 1332 | * group_no and gdp correctly point to the last group visited. |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1333 | */ |
| 1334 | for (bgi = 0; bgi < ngroups; bgi++) { |
| 1335 | group_no++; |
| 1336 | if (group_no >= ngroups) |
| 1337 | group_no = 0; |
| 1338 | gdp = ext2_get_group_desc(sb, group_no, &gdp_bh); |
| 1339 | if (!gdp) |
| 1340 | goto io_error; |
| 1341 | |
| 1342 | free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); |
| 1343 | /* |
Jan Kara | 4689153 | 2010-03-29 13:55:39 +0200 | [diff] [blame] | 1344 | * skip this group (and avoid loading bitmap) if there |
| 1345 | * are no free blocks |
| 1346 | */ |
| 1347 | if (!free_blocks) |
| 1348 | continue; |
| 1349 | /* |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1350 | * skip this group if the number of |
| 1351 | * free blocks is less than half of the reservation |
| 1352 | * window size. |
| 1353 | */ |
Mingming Cao | d707d31 | 2008-10-15 22:04:01 -0700 | [diff] [blame] | 1354 | if (my_rsv && (free_blocks <= (windowsz/2))) |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1355 | continue; |
| 1356 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | brelse(bitmap_bh); |
| 1358 | bitmap_bh = read_block_bitmap(sb, group_no); |
| 1359 | if (!bitmap_bh) |
| 1360 | goto io_error; |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1361 | /* |
| 1362 | * try to allocate block(s) from this group, without a goal(-1). |
| 1363 | */ |
| 1364 | grp_alloc_blk = ext2_try_to_allocate_with_rsv(sb, group_no, |
| 1365 | bitmap_bh, -1, my_rsv, &num); |
| 1366 | if (grp_alloc_blk >= 0) |
| 1367 | goto allocated; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | /* |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 1370 | * We may end up a bogus earlier ENOSPC error due to |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1371 | * filesystem is "full" of reservations, but |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 1372 | * there maybe indeed free blocks available on disk |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1373 | * In this case, we just forget about the reservations |
| 1374 | * just do block allocation as without reservations. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1375 | */ |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1376 | if (my_rsv) { |
| 1377 | my_rsv = NULL; |
| 1378 | windowsz = 0; |
| 1379 | group_no = goal_group; |
| 1380 | goto retry_alloc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1381 | } |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1382 | /* No space left on the device */ |
| 1383 | *errp = -ENOSPC; |
| 1384 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1386 | allocated: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | ext2_debug("using block group %d(%d)\n", |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1389 | group_no, gdp->bg_free_blocks_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1391 | ret_block = grp_alloc_blk + ext2_group_first_block_no(sb, group_no); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1392 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1393 | if (in_range(le32_to_cpu(gdp->bg_block_bitmap), ret_block, num) || |
| 1394 | in_range(le32_to_cpu(gdp->bg_inode_bitmap), ret_block, num) || |
| 1395 | in_range(ret_block, le32_to_cpu(gdp->bg_inode_table), |
| 1396 | EXT2_SB(sb)->s_itb_per_group) || |
| 1397 | in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table), |
Aneesh Kumar K.V | 7f0adae | 2008-02-06 01:36:17 -0800 | [diff] [blame] | 1398 | EXT2_SB(sb)->s_itb_per_group)) { |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1399 | ext2_error(sb, "ext2_new_blocks", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1400 | "Allocating block in system zone - " |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1401 | "blocks from "E2FSBLK", length %lu", |
| 1402 | ret_block, num); |
Aneesh Kumar K.V | 8b91582 | 2008-04-28 02:16:04 -0700 | [diff] [blame] | 1403 | /* |
| 1404 | * ext2_try_to_allocate marked the blocks we allocated as in |
| 1405 | * use. So we may want to selectively mark some of the blocks |
| 1406 | * as free |
| 1407 | */ |
| 1408 | goto retry_alloc; |
Aneesh Kumar K.V | 7f0adae | 2008-02-06 01:36:17 -0800 | [diff] [blame] | 1409 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1411 | performed_allocation = 1; |
| 1412 | |
| 1413 | if (ret_block + num - 1 >= le32_to_cpu(es->s_blocks_count)) { |
| 1414 | ext2_error(sb, "ext2_new_blocks", |
| 1415 | "block("E2FSBLK") >= blocks count(%d) - " |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | "block_group = %d, es == %p ", ret_block, |
| 1417 | le32_to_cpu(es->s_blocks_count), group_no, es); |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1418 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1421 | group_adjust_blocks(sb, group_no, gdp, gdp_bh, -num); |
| 1422 | percpu_counter_sub(&sbi->s_freeblocks_counter, num); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | |
| 1424 | mark_buffer_dirty(bitmap_bh); |
| 1425 | if (sb->s_flags & MS_SYNCHRONOUS) |
| 1426 | sync_dirty_buffer(bitmap_bh); |
| 1427 | |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1428 | *errp = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1429 | brelse(bitmap_bh); |
Wang Shilong | 8e3dffc | 2013-02-07 22:57:53 +0800 | [diff] [blame] | 1430 | if (num < *count) { |
| 1431 | dquot_free_block_nodirty(inode, *count-num); |
| 1432 | mark_inode_dirty(inode); |
| 1433 | *count = num; |
| 1434 | } |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1435 | return ret_block; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | |
| 1437 | io_error: |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1438 | *errp = -EIO; |
| 1439 | out: |
| 1440 | /* |
| 1441 | * Undo the block allocation |
| 1442 | */ |
Al Viro | 3889717 | 2010-07-22 01:13:36 +0400 | [diff] [blame] | 1443 | if (!performed_allocation) { |
| 1444 | dquot_free_block_nodirty(inode, *count); |
| 1445 | mark_inode_dirty(inode); |
| 1446 | } |
Martin J. Bligh | a686cd8 | 2007-10-16 23:30:46 -0700 | [diff] [blame] | 1447 | brelse(bitmap_bh); |
| 1448 | return 0; |
| 1449 | } |
| 1450 | |
| 1451 | ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp) |
| 1452 | { |
| 1453 | unsigned long count = 1; |
| 1454 | |
| 1455 | return ext2_new_blocks(inode, goal, &count, errp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | } |
| 1457 | |
Valerie Henson | 21730ee | 2006-06-25 05:48:12 -0700 | [diff] [blame] | 1458 | #ifdef EXT2FS_DEBUG |
| 1459 | |
Akinobu Mita | ecd0afa | 2012-07-30 14:41:05 -0700 | [diff] [blame] | 1460 | unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars) |
Valerie Henson | 21730ee | 2006-06-25 05:48:12 -0700 | [diff] [blame] | 1461 | { |
Akinobu Mita | ecd0afa | 2012-07-30 14:41:05 -0700 | [diff] [blame] | 1462 | return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars); |
Valerie Henson | 21730ee | 2006-06-25 05:48:12 -0700 | [diff] [blame] | 1463 | } |
| 1464 | |
| 1465 | #endif /* EXT2FS_DEBUG */ |
| 1466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | unsigned long ext2_count_free_blocks (struct super_block * sb) |
| 1468 | { |
| 1469 | struct ext2_group_desc * desc; |
| 1470 | unsigned long desc_count = 0; |
| 1471 | int i; |
| 1472 | #ifdef EXT2FS_DEBUG |
| 1473 | unsigned long bitmap_count, x; |
| 1474 | struct ext2_super_block *es; |
| 1475 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1476 | es = EXT2_SB(sb)->s_es; |
| 1477 | desc_count = 0; |
| 1478 | bitmap_count = 0; |
| 1479 | desc = NULL; |
| 1480 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { |
| 1481 | struct buffer_head *bitmap_bh; |
| 1482 | desc = ext2_get_group_desc (sb, i, NULL); |
| 1483 | if (!desc) |
| 1484 | continue; |
| 1485 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); |
| 1486 | bitmap_bh = read_block_bitmap(sb, i); |
| 1487 | if (!bitmap_bh) |
| 1488 | continue; |
| 1489 | |
| 1490 | x = ext2_count_free(bitmap_bh, sb->s_blocksize); |
| 1491 | printk ("group %d: stored = %d, counted = %lu\n", |
| 1492 | i, le16_to_cpu(desc->bg_free_blocks_count), x); |
| 1493 | bitmap_count += x; |
| 1494 | brelse(bitmap_bh); |
| 1495 | } |
| 1496 | printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n", |
| 1497 | (long)le32_to_cpu(es->s_free_blocks_count), |
| 1498 | desc_count, bitmap_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | return bitmap_count; |
| 1500 | #else |
| 1501 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { |
| 1502 | desc = ext2_get_group_desc (sb, i, NULL); |
| 1503 | if (!desc) |
| 1504 | continue; |
| 1505 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); |
| 1506 | } |
| 1507 | return desc_count; |
| 1508 | #endif |
| 1509 | } |
| 1510 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1511 | static inline int test_root(int a, int b) |
| 1512 | { |
| 1513 | int num = b; |
| 1514 | |
| 1515 | while (a > num) |
| 1516 | num *= b; |
| 1517 | return num == a; |
| 1518 | } |
| 1519 | |
| 1520 | static int ext2_group_sparse(int group) |
| 1521 | { |
| 1522 | if (group <= 1) |
| 1523 | return 1; |
| 1524 | return (test_root(group, 3) || test_root(group, 5) || |
| 1525 | test_root(group, 7)); |
| 1526 | } |
| 1527 | |
| 1528 | /** |
| 1529 | * ext2_bg_has_super - number of blocks used by the superblock in group |
| 1530 | * @sb: superblock for filesystem |
| 1531 | * @group: group number to check |
| 1532 | * |
| 1533 | * Return the number of blocks used by the superblock (primary or backup) |
| 1534 | * in this group. Currently this will be only 0 or 1. |
| 1535 | */ |
| 1536 | int ext2_bg_has_super(struct super_block *sb, int group) |
| 1537 | { |
| 1538 | if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& |
| 1539 | !ext2_group_sparse(group)) |
| 1540 | return 0; |
| 1541 | return 1; |
| 1542 | } |
| 1543 | |
| 1544 | /** |
| 1545 | * ext2_bg_num_gdb - number of blocks used by the group table in group |
| 1546 | * @sb: superblock for filesystem |
| 1547 | * @group: group number to check |
| 1548 | * |
| 1549 | * Return the number of blocks used by the group descriptor table |
| 1550 | * (primary or backup) in this group. In the future there may be a |
| 1551 | * different number of descriptor blocks in each group. |
| 1552 | */ |
| 1553 | unsigned long ext2_bg_num_gdb(struct super_block *sb, int group) |
| 1554 | { |
Akinobu Mita | 859cb93 | 2008-02-06 01:40:17 -0800 | [diff] [blame] | 1555 | return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1556 | } |
| 1557 | |