blob: 41f6ef68e2e1e8c7fedfb5f5faaf575d6df3bb81 [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/resize.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
Mingming Cao617ba132006-10-11 01:20:53 -07004 * Support for resizing an ext4 filesystem while it is mounted.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07005 *
6 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
7 *
8 * This could probably be made into a module, because it is not often in use.
9 */
10
11
Mingming Cao617ba132006-10-11 01:20:53 -070012#define EXT4FS_DEBUG
Dave Kleikampac27a0e2006-10-11 01:20:50 -070013
Dave Kleikampac27a0e2006-10-11 01:20:50 -070014#include <linux/errno.h>
15#include <linux/slab.h>
16
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040017#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070018
Yongqiang Yang8f82f842011-07-26 21:35:44 -040019int ext4_resize_begin(struct super_block *sb)
20{
21 int ret = 0;
22
23 if (!capable(CAP_SYS_RESOURCE))
24 return -EPERM;
25
Yongqiang Yangce723c32011-07-26 21:39:09 -040026 /*
27 * We are not allowed to do online-resizing on a filesystem mounted
28 * with error, because it can destroy the filesystem easily.
29 */
30 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
31 ext4_warning(sb, "There are errors in the filesystem, "
32 "so online resizing is not allowed\n");
33 return -EPERM;
34 }
35
Yongqiang Yang8f82f842011-07-26 21:35:44 -040036 if (test_and_set_bit_lock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags))
37 ret = -EBUSY;
38
39 return ret;
40}
41
42void ext4_resize_end(struct super_block *sb)
43{
44 clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags);
45 smp_mb__after_clear_bit();
46}
47
Dave Kleikampac27a0e2006-10-11 01:20:50 -070048#define outside(b, first, last) ((b) < (first) || (b) >= (last))
49#define inside(b, first, last) ((b) >= (first) && (b) < (last))
50
51static int verify_group_input(struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -070052 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070053{
Mingming Cao617ba132006-10-11 01:20:53 -070054 struct ext4_sb_info *sbi = EXT4_SB(sb);
55 struct ext4_super_block *es = sbi->s_es;
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070056 ext4_fsblk_t start = ext4_blocks_count(es);
Mingming Cao617ba132006-10-11 01:20:53 -070057 ext4_fsblk_t end = start + input->blocks_count;
Avantika Mathurfd2d4292008-01-28 23:58:27 -050058 ext4_group_t group = input->group;
Mingming Cao617ba132006-10-11 01:20:53 -070059 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
60 unsigned overhead = ext4_bg_has_super(sb, group) ?
61 (1 + ext4_bg_num_gdb(sb, group) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -070062 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
Mingming Cao617ba132006-10-11 01:20:53 -070063 ext4_fsblk_t metaend = start + overhead;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070064 struct buffer_head *bh = NULL;
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070065 ext4_grpblk_t free_blocks_count, offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070066 int err = -EINVAL;
67
68 input->free_blocks_count = free_blocks_count =
69 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
70
71 if (test_opt(sb, DEBUG))
Mingming Cao617ba132006-10-11 01:20:53 -070072 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
Dave Kleikampac27a0e2006-10-11 01:20:50 -070073 "(%d free, %u reserved)\n",
Mingming Cao617ba132006-10-11 01:20:53 -070074 ext4_bg_has_super(sb, input->group) ? "normal" :
Dave Kleikampac27a0e2006-10-11 01:20:50 -070075 "no-super", input->group, input->blocks_count,
76 free_blocks_count, input->reserved_blocks);
77
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070078 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070079 if (group != sbi->s_groups_count)
Eric Sandeen12062dd2010-02-15 14:19:27 -050080 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070081 input->group, sbi->s_groups_count);
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070082 else if (offset != 0)
Eric Sandeen12062dd2010-02-15 14:19:27 -050083 ext4_warning(sb, "Last group not full");
Dave Kleikampac27a0e2006-10-11 01:20:50 -070084 else if (input->reserved_blocks > input->blocks_count / 5)
Eric Sandeen12062dd2010-02-15 14:19:27 -050085 ext4_warning(sb, "Reserved blocks too high (%u)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070086 input->reserved_blocks);
87 else if (free_blocks_count < 0)
Eric Sandeen12062dd2010-02-15 14:19:27 -050088 ext4_warning(sb, "Bad blocks count %u",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070089 input->blocks_count);
90 else if (!(bh = sb_bread(sb, end - 1)))
Eric Sandeen12062dd2010-02-15 14:19:27 -050091 ext4_warning(sb, "Cannot read last block (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092 end - 1);
93 else if (outside(input->block_bitmap, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -050094 ext4_warning(sb, "Block bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070095 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070096 else if (outside(input->inode_bitmap, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -050097 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070098 (unsigned long long)input->inode_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070099 else if (outside(input->inode_table, start, end) ||
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400100 outside(itend - 1, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500101 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700102 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103 else if (input->inode_bitmap == input->block_bitmap)
Eric Sandeen12062dd2010-02-15 14:19:27 -0500104 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700105 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700106 else if (inside(input->block_bitmap, input->inode_table, itend))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500107 ext4_warning(sb, "Block bitmap (%llu) in inode table "
108 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700109 (unsigned long long)input->block_bitmap,
110 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700111 else if (inside(input->inode_bitmap, input->inode_table, itend))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500112 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
113 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700114 (unsigned long long)input->inode_bitmap,
115 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116 else if (inside(input->block_bitmap, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500117 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700118 (unsigned long long)input->block_bitmap,
119 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700120 else if (inside(input->inode_bitmap, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500121 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700122 (unsigned long long)input->inode_bitmap,
123 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700124 else if (inside(input->inode_table, start, metaend) ||
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400125 inside(itend - 1, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -0500126 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
127 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700128 (unsigned long long)input->inode_table,
129 itend - 1, start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700130 else
131 err = 0;
132 brelse(bh);
133
134 return err;
135}
136
Yongqiang Yang28c7bac2012-01-03 23:22:50 -0500137/*
138 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex
139 * group each time.
140 */
141struct ext4_new_flex_group_data {
142 struct ext4_new_group_data *groups; /* new_group_data for groups
143 in the flex group */
144 __u16 *bg_flags; /* block group flags of groups
145 in @groups */
146 ext4_group_t count; /* number of groups in @groups
147 */
148};
149
150/*
151 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of
152 * @flexbg_size.
153 *
154 * Returns NULL on failure otherwise address of the allocated structure.
155 */
156static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size)
157{
158 struct ext4_new_flex_group_data *flex_gd;
159
160 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS);
161 if (flex_gd == NULL)
162 goto out3;
163
Haogang Chen967ac8a2012-05-28 14:21:55 -0400164 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data))
165 goto out2;
Yongqiang Yang28c7bac2012-01-03 23:22:50 -0500166 flex_gd->count = flexbg_size;
167
168 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) *
169 flexbg_size, GFP_NOFS);
170 if (flex_gd->groups == NULL)
171 goto out2;
172
173 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS);
174 if (flex_gd->bg_flags == NULL)
175 goto out1;
176
177 return flex_gd;
178
179out1:
180 kfree(flex_gd->groups);
181out2:
182 kfree(flex_gd);
183out3:
184 return NULL;
185}
186
187static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd)
188{
189 kfree(flex_gd->bg_flags);
190 kfree(flex_gd->groups);
191 kfree(flex_gd);
192}
193
Yongqiang Yang3fbea4b2012-01-03 23:44:38 -0500194/*
195 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps
196 * and inode tables for a flex group.
197 *
198 * This function is used by 64bit-resize. Note that this function allocates
199 * group tables from the 1st group of groups contained by @flexgd, which may
200 * be a partial of a flex group.
201 *
202 * @sb: super block of fs to which the groups belongs
203 */
204static void ext4_alloc_group_tables(struct super_block *sb,
205 struct ext4_new_flex_group_data *flex_gd,
206 int flexbg_size)
207{
208 struct ext4_new_group_data *group_data = flex_gd->groups;
209 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
210 ext4_fsblk_t start_blk;
211 ext4_fsblk_t last_blk;
212 ext4_group_t src_group;
213 ext4_group_t bb_index = 0;
214 ext4_group_t ib_index = 0;
215 ext4_group_t it_index = 0;
216 ext4_group_t group;
217 ext4_group_t last_group;
218 unsigned overhead;
219
220 BUG_ON(flex_gd->count == 0 || group_data == NULL);
221
222 src_group = group_data[0].group;
223 last_group = src_group + flex_gd->count - 1;
224
225 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) !=
226 (last_group & ~(flexbg_size - 1))));
227next_group:
228 group = group_data[0].group;
229 start_blk = ext4_group_first_block_no(sb, src_group);
230 last_blk = start_blk + group_data[src_group - group].blocks_count;
231
232 overhead = ext4_bg_has_super(sb, src_group) ?
233 (1 + ext4_bg_num_gdb(sb, src_group) +
234 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
235
236 start_blk += overhead;
237
238 BUG_ON(src_group >= group_data[0].group + flex_gd->count);
239 /* We collect contiguous blocks as much as possible. */
240 src_group++;
241 for (; src_group <= last_group; src_group++)
242 if (!ext4_bg_has_super(sb, src_group))
243 last_blk += group_data[src_group - group].blocks_count;
244 else
245 break;
246
247 /* Allocate block bitmaps */
248 for (; bb_index < flex_gd->count; bb_index++) {
249 if (start_blk >= last_blk)
250 goto next_group;
251 group_data[bb_index].block_bitmap = start_blk++;
252 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
253 group -= group_data[0].group;
254 group_data[group].free_blocks_count--;
255 if (flexbg_size > 1)
256 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
257 }
258
259 /* Allocate inode bitmaps */
260 for (; ib_index < flex_gd->count; ib_index++) {
261 if (start_blk >= last_blk)
262 goto next_group;
263 group_data[ib_index].inode_bitmap = start_blk++;
264 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL);
265 group -= group_data[0].group;
266 group_data[group].free_blocks_count--;
267 if (flexbg_size > 1)
268 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
269 }
270
271 /* Allocate inode tables */
272 for (; it_index < flex_gd->count; it_index++) {
273 if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk)
274 goto next_group;
275 group_data[it_index].inode_table = start_blk;
276 ext4_get_group_no_and_offset(sb, start_blk, &group, NULL);
277 group -= group_data[0].group;
278 group_data[group].free_blocks_count -=
279 EXT4_SB(sb)->s_itb_per_group;
280 if (flexbg_size > 1)
281 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT;
282
283 start_blk += EXT4_SB(sb)->s_itb_per_group;
284 }
285
286 if (test_opt(sb, DEBUG)) {
287 int i;
288 group = group_data[0].group;
289
290 printk(KERN_DEBUG "EXT4-fs: adding a flex group with "
291 "%d groups, flexbg size is %d:\n", flex_gd->count,
292 flexbg_size);
293
294 for (i = 0; i < flex_gd->count; i++) {
295 printk(KERN_DEBUG "adding %s group %u: %u "
296 "blocks (%d free)\n",
297 ext4_bg_has_super(sb, group + i) ? "normal" :
298 "no-super", group + i,
299 group_data[i].blocks_count,
300 group_data[i].free_blocks_count);
301 }
302 }
303}
304
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700305static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -0700306 ext4_fsblk_t blk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700307{
308 struct buffer_head *bh;
309 int err;
310
311 bh = sb_getblk(sb, blk);
312 if (!bh)
313 return ERR_PTR(-EIO);
Mingming Cao617ba132006-10-11 01:20:53 -0700314 if ((err = ext4_journal_get_write_access(handle, bh))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700315 brelse(bh);
316 bh = ERR_PTR(err);
317 } else {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700318 memset(bh->b_data, 0, sb->s_blocksize);
319 set_buffer_uptodate(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700320 }
321
322 return bh;
323}
324
325/*
Eric Sandeen14904102007-10-16 18:38:25 -0400326 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
327 * If that fails, restart the transaction & regain write access for the
328 * buffer head which is used for block_bitmap modifications.
329 */
Yongqiang Yang6d40bc52011-07-26 22:24:41 -0400330static int extend_or_restart_transaction(handle_t *handle, int thresh)
Eric Sandeen14904102007-10-16 18:38:25 -0400331{
332 int err;
333
Frank Mayhar03901312009-01-07 00:06:22 -0500334 if (ext4_handle_has_enough_credits(handle, thresh))
Eric Sandeen14904102007-10-16 18:38:25 -0400335 return 0;
336
337 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
338 if (err < 0)
339 return err;
340 if (err) {
Yongqiang Yang6d40bc52011-07-26 22:24:41 -0400341 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
342 if (err)
Eric Sandeen14904102007-10-16 18:38:25 -0400343 return err;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400344 }
Eric Sandeen14904102007-10-16 18:38:25 -0400345
346 return 0;
347}
348
349/*
Yongqiang Yang33afdcc2012-01-03 23:32:52 -0500350 * set_flexbg_block_bitmap() mark @count blocks starting from @block used.
351 *
352 * Helper function for ext4_setup_new_group_blocks() which set .
353 *
354 * @sb: super block
355 * @handle: journal handle
356 * @flex_gd: flex group data
357 */
358static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
359 struct ext4_new_flex_group_data *flex_gd,
360 ext4_fsblk_t block, ext4_group_t count)
361{
362 ext4_group_t count2;
363
364 ext4_debug("mark blocks [%llu/%u] used\n", block, count);
365 for (count2 = count; count > 0; count -= count2, block += count2) {
366 ext4_fsblk_t start;
367 struct buffer_head *bh;
368 ext4_group_t group;
369 int err;
370
371 ext4_get_group_no_and_offset(sb, block, &group, NULL);
372 start = ext4_group_first_block_no(sb, group);
373 group -= flex_gd->groups[0].group;
374
375 count2 = sb->s_blocksize * 8 - (block - start);
376 if (count2 > count)
377 count2 = count;
378
379 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) {
380 BUG_ON(flex_gd->count > 1);
381 continue;
382 }
383
384 err = extend_or_restart_transaction(handle, 1);
385 if (err)
386 return err;
387
388 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap);
389 if (!bh)
390 return -EIO;
391
392 err = ext4_journal_get_write_access(handle, bh);
393 if (err)
394 return err;
395 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block,
396 block - start, count2);
397 ext4_set_bits(bh->b_data, block - start, count2);
398
399 err = ext4_handle_dirty_metadata(handle, NULL, bh);
400 if (unlikely(err))
401 return err;
402 brelse(bh);
403 }
404
405 return 0;
406}
407
408/*
409 * Set up the block and inode bitmaps, and the inode table for the new groups.
410 * This doesn't need to be part of the main transaction, since we are only
411 * changing blocks outside the actual filesystem. We still do journaling to
412 * ensure the recovery is correct in case of a failure just after resize.
413 * If any part of this fails, we simply abort the resize.
414 *
415 * setup_new_flex_group_blocks handles a flex group as follow:
416 * 1. copy super block and GDT, and initialize group tables if necessary.
417 * In this step, we only set bits in blocks bitmaps for blocks taken by
418 * super block and GDT.
419 * 2. allocate group tables in block bitmaps, that is, set bits in block
420 * bitmap for blocks taken by group tables.
421 */
422static int setup_new_flex_group_blocks(struct super_block *sb,
423 struct ext4_new_flex_group_data *flex_gd)
424{
425 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group};
426 ext4_fsblk_t start;
427 ext4_fsblk_t block;
428 struct ext4_sb_info *sbi = EXT4_SB(sb);
429 struct ext4_super_block *es = sbi->s_es;
430 struct ext4_new_group_data *group_data = flex_gd->groups;
431 __u16 *bg_flags = flex_gd->bg_flags;
432 handle_t *handle;
433 ext4_group_t group, count;
434 struct buffer_head *bh = NULL;
435 int reserved_gdb, i, j, err = 0, err2;
436
437 BUG_ON(!flex_gd->count || !group_data ||
438 group_data[0].group != sbi->s_groups_count);
439
440 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
441
442 /* This transaction may be extended/restarted along the way */
443 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
444 if (IS_ERR(handle))
445 return PTR_ERR(handle);
446
447 group = group_data[0].group;
448 for (i = 0; i < flex_gd->count; i++, group++) {
449 unsigned long gdblocks;
450
451 gdblocks = ext4_bg_num_gdb(sb, group);
452 start = ext4_group_first_block_no(sb, group);
453
454 /* Copy all of the GDT blocks into the backup in this group */
455 for (j = 0, block = start + 1; j < gdblocks; j++, block++) {
456 struct buffer_head *gdb;
457
458 ext4_debug("update backup group %#04llx\n", block);
459 err = extend_or_restart_transaction(handle, 1);
460 if (err)
461 goto out;
462
463 gdb = sb_getblk(sb, block);
464 if (!gdb) {
465 err = -EIO;
466 goto out;
467 }
468
469 err = ext4_journal_get_write_access(handle, gdb);
470 if (err) {
471 brelse(gdb);
472 goto out;
473 }
474 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data,
475 gdb->b_size);
476 set_buffer_uptodate(gdb);
477
478 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
479 if (unlikely(err)) {
480 brelse(gdb);
481 goto out;
482 }
483 brelse(gdb);
484 }
485
486 /* Zero out all of the reserved backup group descriptor
487 * table blocks
488 */
489 if (ext4_bg_has_super(sb, group)) {
490 err = sb_issue_zeroout(sb, gdblocks + start + 1,
491 reserved_gdb, GFP_NOFS);
492 if (err)
493 goto out;
494 }
495
496 /* Initialize group tables of the grop @group */
497 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
498 goto handle_bb;
499
500 /* Zero out all of the inode table blocks */
501 block = group_data[i].inode_table;
502 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n",
503 block, sbi->s_itb_per_group);
504 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group,
505 GFP_NOFS);
506 if (err)
507 goto out;
508
509handle_bb:
510 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT)
511 goto handle_ib;
512
513 /* Initialize block bitmap of the @group */
514 block = group_data[i].block_bitmap;
515 err = extend_or_restart_transaction(handle, 1);
516 if (err)
517 goto out;
518
519 bh = bclean(handle, sb, block);
520 if (IS_ERR(bh)) {
521 err = PTR_ERR(bh);
522 goto out;
523 }
524 if (ext4_bg_has_super(sb, group)) {
525 ext4_debug("mark backup superblock %#04llx (+0)\n",
526 start);
527 ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb +
528 1);
529 }
530 ext4_mark_bitmap_end(group_data[i].blocks_count,
531 sb->s_blocksize * 8, bh->b_data);
532 err = ext4_handle_dirty_metadata(handle, NULL, bh);
533 if (err)
534 goto out;
535 brelse(bh);
536
537handle_ib:
538 if (bg_flags[i] & EXT4_BG_INODE_UNINIT)
539 continue;
540
541 /* Initialize inode bitmap of the @group */
542 block = group_data[i].inode_bitmap;
543 err = extend_or_restart_transaction(handle, 1);
544 if (err)
545 goto out;
546 /* Mark unused entries in inode bitmap used */
547 bh = bclean(handle, sb, block);
548 if (IS_ERR(bh)) {
549 err = PTR_ERR(bh);
550 goto out;
551 }
552
553 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb),
554 sb->s_blocksize * 8, bh->b_data);
555 err = ext4_handle_dirty_metadata(handle, NULL, bh);
556 if (err)
557 goto out;
558 brelse(bh);
559 }
560 bh = NULL;
561
562 /* Mark group tables in block bitmap */
563 for (j = 0; j < GROUP_TABLE_COUNT; j++) {
564 count = group_table_count[j];
565 start = (&group_data[0].block_bitmap)[j];
566 block = start;
567 for (i = 1; i < flex_gd->count; i++) {
568 block += group_table_count[j];
569 if (block == (&group_data[i].block_bitmap)[j]) {
570 count += group_table_count[j];
571 continue;
572 }
573 err = set_flexbg_block_bitmap(sb, handle,
574 flex_gd, start, count);
575 if (err)
576 goto out;
577 count = group_table_count[j];
578 start = group_data[i].block_bitmap;
579 block = start;
580 }
581
582 if (count) {
583 err = set_flexbg_block_bitmap(sb, handle,
584 flex_gd, start, count);
585 if (err)
586 goto out;
587 }
588 }
589
590out:
591 brelse(bh);
592 err2 = ext4_journal_stop(handle);
593 if (err2 && !err)
594 err = err2;
595
596 return err;
597}
598
599/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700600 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
Mingming Cao617ba132006-10-11 01:20:53 -0700601 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700602 * calling this for the first time. In a sparse filesystem it will be the
603 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
604 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
605 */
Mingming Cao617ba132006-10-11 01:20:53 -0700606static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700607 unsigned *five, unsigned *seven)
608{
609 unsigned *min = three;
610 int mult = 3;
611 unsigned ret;
612
Mingming Cao617ba132006-10-11 01:20:53 -0700613 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
614 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700615 ret = *min;
616 *min += 1;
617 return ret;
618 }
619
620 if (*five < *min) {
621 min = five;
622 mult = 5;
623 }
624 if (*seven < *min) {
625 min = seven;
626 mult = 7;
627 }
628
629 ret = *min;
630 *min *= mult;
631
632 return ret;
633}
634
635/*
636 * Check that all of the backup GDT blocks are held in the primary GDT block.
637 * It is assumed that they are stored in group order. Returns the number of
638 * groups in current filesystem that have BACKUPS, or -ve error code.
639 */
640static int verify_reserved_gdb(struct super_block *sb,
Yongqiang Yangc72df9f2012-01-03 23:43:39 -0500641 ext4_group_t end,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700642 struct buffer_head *primary)
643{
Mingming Cao617ba132006-10-11 01:20:53 -0700644 const ext4_fsblk_t blk = primary->b_blocknr;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700645 unsigned three = 1;
646 unsigned five = 5;
647 unsigned seven = 7;
648 unsigned grp;
649 __le32 *p = (__le32 *)primary->b_data;
650 int gdbackups = 0;
651
Mingming Cao617ba132006-10-11 01:20:53 -0700652 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700653 if (le32_to_cpu(*p++) !=
654 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
Eric Sandeen12062dd2010-02-15 14:19:27 -0500655 ext4_warning(sb, "reserved GDT %llu"
Mingming Cao2ae02102006-10-11 01:21:11 -0700656 " missing grp %d (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700657 blk, grp,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700658 grp *
659 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
660 blk);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700661 return -EINVAL;
662 }
Mingming Cao617ba132006-10-11 01:20:53 -0700663 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700664 return -EFBIG;
665 }
666
667 return gdbackups;
668}
669
670/*
671 * Called when we need to bring a reserved group descriptor table block into
672 * use from the resize inode. The primary copy of the new GDT block currently
673 * is an indirect block (under the double indirect block in the resize inode).
674 * The new backup GDT blocks will be stored as leaf blocks in this indirect
675 * block, in group order. Even though we know all the block numbers we need,
676 * we check to ensure that the resize inode has actually reserved these blocks.
677 *
678 * Don't need to update the block bitmaps because the blocks are still in use.
679 *
680 * We get all of the error cases out of the way, so that we are sure to not
681 * fail once we start modifying the data on disk, because JBD has no rollback.
682 */
683static int add_new_gdb(handle_t *handle, struct inode *inode,
Yongqiang Yang2f919712011-07-27 21:16:33 -0400684 ext4_group_t group)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700685{
686 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700687 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
Yongqiang Yang2f919712011-07-27 21:16:33 -0400688 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
Mingming Cao617ba132006-10-11 01:20:53 -0700689 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700690 struct buffer_head **o_group_desc, **n_group_desc;
691 struct buffer_head *dind;
Yongqiang Yang2f919712011-07-27 21:16:33 -0400692 struct buffer_head *gdb_bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700693 int gdbackups;
Mingming Cao617ba132006-10-11 01:20:53 -0700694 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700695 __le32 *data;
696 int err;
697
698 if (test_opt(sb, DEBUG))
699 printk(KERN_DEBUG
Mingming Cao617ba132006-10-11 01:20:53 -0700700 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700701 gdb_num);
702
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400703 /*
704 * If we are not using the primary superblock/GDT copy don't resize,
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400705 * because the user tools have no way of handling this. Probably a
706 * bad time to do it anyways.
707 */
Mingming Cao617ba132006-10-11 01:20:53 -0700708 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
709 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500710 ext4_warning(sb, "won't resize using backup superblock at %llu",
Mingming Cao617ba132006-10-11 01:20:53 -0700711 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700712 return -EPERM;
713 }
714
Yongqiang Yang2f919712011-07-27 21:16:33 -0400715 gdb_bh = sb_bread(sb, gdblock);
716 if (!gdb_bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700717 return -EIO;
718
Yongqiang Yangc72df9f2012-01-03 23:43:39 -0500719 gdbackups = verify_reserved_gdb(sb, group, gdb_bh);
Yongqiang Yang2f919712011-07-27 21:16:33 -0400720 if (gdbackups < 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700721 err = gdbackups;
722 goto exit_bh;
723 }
724
Mingming Cao617ba132006-10-11 01:20:53 -0700725 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700726 dind = sb_bread(sb, le32_to_cpu(*data));
727 if (!dind) {
728 err = -EIO;
729 goto exit_bh;
730 }
731
732 data = (__le32 *)dind->b_data;
Mingming Cao617ba132006-10-11 01:20:53 -0700733 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500734 ext4_warning(sb, "new group %u GDT block %llu not reserved",
Yongqiang Yang2f919712011-07-27 21:16:33 -0400735 group, gdblock);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700736 err = -EINVAL;
737 goto exit_dind;
738 }
739
Theodore Ts'ob4097142011-01-10 12:46:59 -0500740 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
741 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700742 goto exit_dind;
743
Yongqiang Yang2f919712011-07-27 21:16:33 -0400744 err = ext4_journal_get_write_access(handle, gdb_bh);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500745 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700746 goto exit_sbh;
747
Theodore Ts'ob4097142011-01-10 12:46:59 -0500748 err = ext4_journal_get_write_access(handle, dind);
749 if (unlikely(err))
750 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700751
Mingming Cao617ba132006-10-11 01:20:53 -0700752 /* ext4_reserve_inode_write() gets a reference on the iloc */
Theodore Ts'ob4097142011-01-10 12:46:59 -0500753 err = ext4_reserve_inode_write(handle, inode, &iloc);
754 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700755 goto exit_dindj;
756
Theodore Ts'of18a5f22011-08-01 08:45:38 -0400757 n_group_desc = ext4_kvmalloc((gdb_num + 1) *
758 sizeof(struct buffer_head *),
759 GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700760 if (!n_group_desc) {
761 err = -ENOMEM;
Theodore Ts'of18a5f22011-08-01 08:45:38 -0400762 ext4_warning(sb, "not enough memory for %lu groups",
763 gdb_num + 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700764 goto exit_inode;
765 }
766
767 /*
768 * Finally, we have all of the possible failures behind us...
769 *
770 * Remove new GDT block from inode double-indirect block and clear out
771 * the new GDT block for use (which also "frees" the backup GDT blocks
772 * from the reserved inode). We don't need to change the bitmaps for
773 * these blocks, because they are marked as in-use from being in the
774 * reserved inode, and will become GDT blocks (primary and backup).
775 */
Mingming Cao617ba132006-10-11 01:20:53 -0700776 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
Theodore Ts'ob4097142011-01-10 12:46:59 -0500777 err = ext4_handle_dirty_metadata(handle, NULL, dind);
778 if (unlikely(err)) {
779 ext4_std_error(sb, err);
780 goto exit_inode;
781 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700782 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700783 ext4_mark_iloc_dirty(handle, inode, &iloc);
Yongqiang Yang2f919712011-07-27 21:16:33 -0400784 memset(gdb_bh->b_data, 0, sb->s_blocksize);
785 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500786 if (unlikely(err)) {
787 ext4_std_error(sb, err);
788 goto exit_inode;
789 }
790 brelse(dind);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700791
Mingming Cao617ba132006-10-11 01:20:53 -0700792 o_group_desc = EXT4_SB(sb)->s_group_desc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700793 memcpy(n_group_desc, o_group_desc,
Mingming Cao617ba132006-10-11 01:20:53 -0700794 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
Yongqiang Yang2f919712011-07-27 21:16:33 -0400795 n_group_desc[gdb_num] = gdb_bh;
Mingming Cao617ba132006-10-11 01:20:53 -0700796 EXT4_SB(sb)->s_group_desc = n_group_desc;
797 EXT4_SB(sb)->s_gdb_count++;
Theodore Ts'of18a5f22011-08-01 08:45:38 -0400798 ext4_kvfree(o_group_desc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700799
Marcin Slusarze8546d02008-04-17 10:38:59 -0400800 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
Artem Bityutskiyb50924c2012-07-22 20:37:31 -0400801 err = ext4_handle_dirty_super(handle, sb);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500802 if (err)
803 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700804
Theodore Ts'ob4097142011-01-10 12:46:59 -0500805 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700806
807exit_inode:
Theodore Ts'of18a5f22011-08-01 08:45:38 -0400808 ext4_kvfree(n_group_desc);
Amir Goldstein537a0312011-03-20 22:57:02 -0400809 /* ext4_handle_release_buffer(handle, iloc.bh); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700810 brelse(iloc.bh);
811exit_dindj:
Amir Goldstein537a0312011-03-20 22:57:02 -0400812 /* ext4_handle_release_buffer(handle, dind); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700813exit_sbh:
Amir Goldstein537a0312011-03-20 22:57:02 -0400814 /* ext4_handle_release_buffer(handle, EXT4_SB(sb)->s_sbh); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700815exit_dind:
816 brelse(dind);
817exit_bh:
Yongqiang Yang2f919712011-07-27 21:16:33 -0400818 brelse(gdb_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700819
Mingming Cao617ba132006-10-11 01:20:53 -0700820 ext4_debug("leaving with error %d\n", err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700821 return err;
822}
823
824/*
825 * Called when we are adding a new group which has a backup copy of each of
826 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
827 * We need to add these reserved backup GDT blocks to the resize inode, so
828 * that they are kept for future resizing and not allocated to files.
829 *
830 * Each reserved backup GDT block will go into a different indirect block.
831 * The indirect blocks are actually the primary reserved GDT blocks,
832 * so we know in advance what their block numbers are. We only get the
833 * double-indirect block to verify it is pointing to the primary reserved
834 * GDT blocks so we don't overwrite a data block by accident. The reserved
835 * backup GDT blocks are stored in their reserved primary GDT block.
836 */
837static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
Yongqiang Yang668f4dc2011-07-27 21:23:13 -0400838 ext4_group_t group)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700839{
840 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700841 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700842 struct buffer_head **primary;
843 struct buffer_head *dind;
Mingming Cao617ba132006-10-11 01:20:53 -0700844 struct ext4_iloc iloc;
845 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700846 __le32 *data, *end;
847 int gdbackups = 0;
848 int res, i;
849 int err;
850
Josef Bacik216553c2008-04-29 22:02:02 -0400851 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700852 if (!primary)
853 return -ENOMEM;
854
Mingming Cao617ba132006-10-11 01:20:53 -0700855 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700856 dind = sb_bread(sb, le32_to_cpu(*data));
857 if (!dind) {
858 err = -EIO;
859 goto exit_free;
860 }
861
Mingming Cao617ba132006-10-11 01:20:53 -0700862 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
Josef Bacik94460092008-06-06 18:05:52 -0400863 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
864 EXT4_ADDR_PER_BLOCK(sb));
Mingming Cao617ba132006-10-11 01:20:53 -0700865 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700866
867 /* Get each reserved primary GDT block and verify it holds backups */
868 for (res = 0; res < reserved_gdb; res++, blk++) {
869 if (le32_to_cpu(*data) != blk) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500870 ext4_warning(sb, "reserved block %llu"
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700871 " not at offset %ld",
872 blk,
873 (long)(data - (__le32 *)dind->b_data));
874 err = -EINVAL;
875 goto exit_bh;
876 }
877 primary[res] = sb_bread(sb, blk);
878 if (!primary[res]) {
879 err = -EIO;
880 goto exit_bh;
881 }
Yongqiang Yangc72df9f2012-01-03 23:43:39 -0500882 gdbackups = verify_reserved_gdb(sb, group, primary[res]);
883 if (gdbackups < 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700884 brelse(primary[res]);
885 err = gdbackups;
886 goto exit_bh;
887 }
888 if (++data >= end)
889 data = (__le32 *)dind->b_data;
890 }
891
892 for (i = 0; i < reserved_gdb; i++) {
Mingming Cao617ba132006-10-11 01:20:53 -0700893 if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700894 /*
895 int j;
896 for (j = 0; j < i; j++)
Amir Goldstein537a0312011-03-20 22:57:02 -0400897 ext4_handle_release_buffer(handle, primary[j]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700898 */
899 goto exit_bh;
900 }
901 }
902
Mingming Cao617ba132006-10-11 01:20:53 -0700903 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700904 goto exit_bh;
905
906 /*
907 * Finally we can add each of the reserved backup GDT blocks from
908 * the new group to its reserved primary GDT block.
909 */
Yongqiang Yang668f4dc2011-07-27 21:23:13 -0400910 blk = group * EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700911 for (i = 0; i < reserved_gdb; i++) {
912 int err2;
913 data = (__le32 *)primary[i]->b_data;
914 /* printk("reserving backup %lu[%u] = %lu\n",
915 primary[i]->b_blocknr, gdbackups,
916 blk + primary[i]->b_blocknr); */
917 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
Frank Mayhar03901312009-01-07 00:06:22 -0500918 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700919 if (!err)
920 err = err2;
921 }
922 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700923 ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700924
925exit_bh:
926 while (--res >= 0)
927 brelse(primary[res]);
928 brelse(dind);
929
930exit_free:
931 kfree(primary);
932
933 return err;
934}
935
936/*
Mingming Cao617ba132006-10-11 01:20:53 -0700937 * Update the backup copies of the ext4 metadata. These don't need to be part
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700938 * of the main resize transaction, because e2fsck will re-write them if there
939 * is a problem (basically only OOM will cause a problem). However, we
940 * _should_ update the backups if possible, in case the primary gets trashed
941 * for some reason and we need to run e2fsck from a backup superblock. The
942 * important part is that the new block and inode counts are in the backup
943 * superblocks, and the location of the new group metadata in the GDT backups.
944 *
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400945 * We do not need take the s_resize_lock for this, because these
946 * blocks are not otherwise touched by the filesystem code when it is
947 * mounted. We don't need to worry about last changing from
948 * sbi->s_groups_count, because the worst that can happen is that we
949 * do not copy the full number of backups at this time. The resize
950 * which changed s_groups_count will backup again.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700951 */
952static void update_backups(struct super_block *sb,
953 int blk_off, char *data, int size)
954{
Mingming Cao617ba132006-10-11 01:20:53 -0700955 struct ext4_sb_info *sbi = EXT4_SB(sb);
Avantika Mathurfd2d4292008-01-28 23:58:27 -0500956 const ext4_group_t last = sbi->s_groups_count;
Mingming Cao617ba132006-10-11 01:20:53 -0700957 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700958 unsigned three = 1;
959 unsigned five = 5;
960 unsigned seven = 7;
Avantika Mathurfd2d4292008-01-28 23:58:27 -0500961 ext4_group_t group;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700962 int rest = sb->s_blocksize - size;
963 handle_t *handle;
964 int err = 0, err2;
965
Mingming Cao617ba132006-10-11 01:20:53 -0700966 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700967 if (IS_ERR(handle)) {
968 group = 1;
969 err = PTR_ERR(handle);
970 goto exit_err;
971 }
972
Darrick J. Wonga9c473172012-04-29 18:29:10 -0400973 ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
974
Mingming Cao617ba132006-10-11 01:20:53 -0700975 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700976 struct buffer_head *bh;
977
978 /* Out of journal space, and can't get more - abort - so sad */
Frank Mayhar03901312009-01-07 00:06:22 -0500979 if (ext4_handle_valid(handle) &&
980 handle->h_buffer_credits == 0 &&
Mingming Cao617ba132006-10-11 01:20:53 -0700981 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
982 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700983 break;
984
985 bh = sb_getblk(sb, group * bpg + blk_off);
986 if (!bh) {
987 err = -EIO;
988 break;
989 }
Mingming Cao617ba132006-10-11 01:20:53 -0700990 ext4_debug("update metadata backup %#04lx\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700991 (unsigned long)bh->b_blocknr);
Mingming Cao617ba132006-10-11 01:20:53 -0700992 if ((err = ext4_journal_get_write_access(handle, bh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700993 break;
994 lock_buffer(bh);
995 memcpy(bh->b_data, data, size);
996 if (rest)
997 memset(bh->b_data + size, 0, rest);
998 set_buffer_uptodate(bh);
999 unlock_buffer(bh);
Theodore Ts'ob4097142011-01-10 12:46:59 -05001000 err = ext4_handle_dirty_metadata(handle, NULL, bh);
1001 if (unlikely(err))
1002 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001003 brelse(bh);
1004 }
Mingming Cao617ba132006-10-11 01:20:53 -07001005 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001006 err = err2;
1007
1008 /*
1009 * Ugh! Need to have e2fsck write the backup copies. It is too
1010 * late to revert the resize, we shouldn't fail just because of
1011 * the backup copies (they are only needed in case of corruption).
1012 *
1013 * However, if we got here we have a journal problem too, so we
1014 * can't really start a transaction to mark the superblock.
1015 * Chicken out and just set the flag on the hope it will be written
1016 * to disk, and if not - we will simply wait until next fsck.
1017 */
1018exit_err:
1019 if (err) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001020 ext4_warning(sb, "can't update backup for group %u (err %d), "
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001021 "forcing fsck on next reboot", group, err);
Mingming Cao617ba132006-10-11 01:20:53 -07001022 sbi->s_mount_state &= ~EXT4_VALID_FS;
1023 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001024 mark_buffer_dirty(sbi->s_sbh);
1025 }
1026}
1027
Yongqiang Yangbb08c1e2012-01-03 23:20:50 -05001028/*
1029 * ext4_add_new_descs() adds @count group descriptor of groups
1030 * starting at @group
1031 *
1032 * @handle: journal handle
1033 * @sb: super block
1034 * @group: the group no. of the first group desc to be added
1035 * @resize_inode: the resize inode
1036 * @count: number of group descriptors to be added
1037 */
1038static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
1039 ext4_group_t group, struct inode *resize_inode,
1040 ext4_group_t count)
1041{
1042 struct ext4_sb_info *sbi = EXT4_SB(sb);
1043 struct ext4_super_block *es = sbi->s_es;
1044 struct buffer_head *gdb_bh;
1045 int i, gdb_off, gdb_num, err = 0;
1046
1047 for (i = 0; i < count; i++, group++) {
1048 int reserved_gdb = ext4_bg_has_super(sb, group) ?
1049 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
1050
1051 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1052 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1053
1054 /*
1055 * We will only either add reserved group blocks to a backup group
1056 * or remove reserved blocks for the first group in a new group block.
1057 * Doing both would be mean more complex code, and sane people don't
1058 * use non-sparse filesystems anymore. This is already checked above.
1059 */
1060 if (gdb_off) {
1061 gdb_bh = sbi->s_group_desc[gdb_num];
1062 err = ext4_journal_get_write_access(handle, gdb_bh);
1063
1064 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group))
1065 err = reserve_backup_gdb(handle, resize_inode, group);
1066 } else
1067 err = add_new_gdb(handle, resize_inode, group);
1068 if (err)
1069 break;
1070 }
1071 return err;
1072}
1073
Darrick J. Wong41a246d2012-04-29 18:33:10 -04001074static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
1075{
1076 struct buffer_head *bh = sb_getblk(sb, block);
1077 if (!bh)
1078 return NULL;
1079
1080 if (bitmap_uptodate(bh))
1081 return bh;
1082
1083 lock_buffer(bh);
1084 if (bh_submit_read(bh) < 0) {
1085 unlock_buffer(bh);
1086 brelse(bh);
1087 return NULL;
1088 }
1089 unlock_buffer(bh);
1090
1091 return bh;
1092}
1093
1094static int ext4_set_bitmap_checksums(struct super_block *sb,
1095 ext4_group_t group,
1096 struct ext4_group_desc *gdp,
1097 struct ext4_new_group_data *group_data)
1098{
1099 struct buffer_head *bh;
1100
1101 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
1102 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
1103 return 0;
1104
1105 bh = ext4_get_bitmap(sb, group_data->inode_bitmap);
1106 if (!bh)
1107 return -EIO;
1108 ext4_inode_bitmap_csum_set(sb, group, gdp, bh,
1109 EXT4_INODES_PER_GROUP(sb) / 8);
1110 brelse(bh);
1111
Darrick J. Wongfa77dcf2012-04-29 18:35:10 -04001112 bh = ext4_get_bitmap(sb, group_data->block_bitmap);
1113 if (!bh)
1114 return -EIO;
1115 ext4_block_bitmap_csum_set(sb, group, gdp, bh,
1116 EXT4_BLOCKS_PER_GROUP(sb) / 8);
1117 brelse(bh);
1118
Darrick J. Wong41a246d2012-04-29 18:33:10 -04001119 return 0;
1120}
1121
Yongqiang Yang083f5b22012-01-03 23:37:31 -05001122/*
1123 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg
1124 */
1125static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb,
1126 struct ext4_new_flex_group_data *flex_gd)
1127{
1128 struct ext4_new_group_data *group_data = flex_gd->groups;
1129 struct ext4_group_desc *gdp;
1130 struct ext4_sb_info *sbi = EXT4_SB(sb);
1131 struct buffer_head *gdb_bh;
1132 ext4_group_t group;
1133 __u16 *bg_flags = flex_gd->bg_flags;
1134 int i, gdb_off, gdb_num, err = 0;
1135
1136
1137 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) {
1138 group = group_data->group;
1139
1140 gdb_off = group % EXT4_DESC_PER_BLOCK(sb);
1141 gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
1142
1143 /*
1144 * get_write_access() has been called on gdb_bh by ext4_add_new_desc().
1145 */
1146 gdb_bh = sbi->s_group_desc[gdb_num];
1147 /* Update group descriptor block for new group */
Theodore Ts'o2716b802012-05-28 17:47:52 -04001148 gdp = (struct ext4_group_desc *)(gdb_bh->b_data +
Yongqiang Yang083f5b22012-01-03 23:37:31 -05001149 gdb_off * EXT4_DESC_SIZE(sb));
1150
1151 memset(gdp, 0, EXT4_DESC_SIZE(sb));
1152 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap);
1153 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap);
Darrick J. Wong41a246d2012-04-29 18:33:10 -04001154 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data);
1155 if (err) {
1156 ext4_std_error(sb, err);
1157 break;
1158 }
1159
Yongqiang Yang083f5b22012-01-03 23:37:31 -05001160 ext4_inode_table_set(sb, gdp, group_data->inode_table);
1161 ext4_free_group_clusters_set(sb, gdp,
1162 EXT4_B2C(sbi, group_data->free_blocks_count));
1163 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
1164 gdp->bg_flags = cpu_to_le16(*bg_flags);
Darrick J. Wongfeb0ab32012-04-29 18:45:10 -04001165 ext4_group_desc_csum_set(sb, group, gdp);
Yongqiang Yang083f5b22012-01-03 23:37:31 -05001166
1167 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh);
1168 if (unlikely(err)) {
1169 ext4_std_error(sb, err);
1170 break;
1171 }
1172
1173 /*
1174 * We can allocate memory for mb_alloc based on the new group
1175 * descriptor
1176 */
1177 err = ext4_mb_add_groupinfo(sb, group, gdp);
1178 if (err)
1179 break;
1180 }
1181 return err;
1182}
1183
Yongqiang Yang2e10e2f2012-01-03 23:41:39 -05001184/*
1185 * ext4_update_super() updates the super block so that the newly added
1186 * groups can be seen by the filesystem.
1187 *
1188 * @sb: super block
1189 * @flex_gd: new added groups
1190 */
1191static void ext4_update_super(struct super_block *sb,
1192 struct ext4_new_flex_group_data *flex_gd)
1193{
1194 ext4_fsblk_t blocks_count = 0;
1195 ext4_fsblk_t free_blocks = 0;
1196 ext4_fsblk_t reserved_blocks = 0;
1197 struct ext4_new_group_data *group_data = flex_gd->groups;
1198 struct ext4_sb_info *sbi = EXT4_SB(sb);
1199 struct ext4_super_block *es = sbi->s_es;
Theodore Ts'o8a991842012-07-22 20:23:31 -04001200 int i;
Yongqiang Yang2e10e2f2012-01-03 23:41:39 -05001201
1202 BUG_ON(flex_gd->count == 0 || group_data == NULL);
1203 /*
1204 * Make the new blocks and inodes valid next. We do this before
1205 * increasing the group count so that once the group is enabled,
1206 * all of its blocks and inodes are already valid.
1207 *
1208 * We always allocate group-by-group, then block-by-block or
1209 * inode-by-inode within a group, so enabling these
1210 * blocks/inodes before the group is live won't actually let us
1211 * allocate the new space yet.
1212 */
1213 for (i = 0; i < flex_gd->count; i++) {
1214 blocks_count += group_data[i].blocks_count;
1215 free_blocks += group_data[i].free_blocks_count;
1216 }
1217
1218 reserved_blocks = ext4_r_blocks_count(es) * 100;
1219 do_div(reserved_blocks, ext4_blocks_count(es));
1220 reserved_blocks *= blocks_count;
1221 do_div(reserved_blocks, 100);
1222
1223 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count);
Darrick J. Wong636d7e2e2012-03-20 15:46:11 -04001224 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks);
Yongqiang Yang2e10e2f2012-01-03 23:41:39 -05001225 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1226 flex_gd->count);
Darrick J. Wong636d7e2e2012-03-20 15:46:11 -04001227 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) *
1228 flex_gd->count);
Yongqiang Yang2e10e2f2012-01-03 23:41:39 -05001229
1230 /*
1231 * We need to protect s_groups_count against other CPUs seeing
1232 * inconsistent state in the superblock.
1233 *
1234 * The precise rules we use are:
1235 *
1236 * * Writers must perform a smp_wmb() after updating all
1237 * dependent data and before modifying the groups count
1238 *
1239 * * Readers must perform an smp_rmb() after reading the groups
1240 * count and before reading any dependent data.
1241 *
1242 * NB. These rules can be relaxed when checking the group count
1243 * while freeing data, as we can only allocate from a block
1244 * group after serialising against the group count, and we can
1245 * only then free after serialising in turn against that
1246 * allocation.
1247 */
1248 smp_wmb();
1249
1250 /* Update the global fs size fields */
1251 sbi->s_groups_count += flex_gd->count;
1252
1253 /* Update the reserved block counts only once the new group is
1254 * active. */
1255 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
1256 reserved_blocks);
1257
1258 /* Update the free space counts */
1259 percpu_counter_add(&sbi->s_freeclusters_counter,
1260 EXT4_B2C(sbi, free_blocks));
1261 percpu_counter_add(&sbi->s_freeinodes_counter,
1262 EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
1263
1264 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
1265 EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
1266 sbi->s_log_groups_per_flex) {
1267 ext4_group_t flex_group;
1268 flex_group = ext4_flex_group(sbi, group_data[0].group);
1269 atomic_add(EXT4_B2C(sbi, free_blocks),
1270 &sbi->s_flex_groups[flex_group].free_clusters);
1271 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count,
1272 &sbi->s_flex_groups[flex_group].free_inodes);
1273 }
1274
Theodore Ts'o952fc182012-07-09 16:27:05 -04001275 /*
1276 * Update the fs overhead information
1277 */
1278 ext4_calculate_overhead(sb);
1279
Yongqiang Yang2e10e2f2012-01-03 23:41:39 -05001280 if (test_opt(sb, DEBUG))
1281 printk(KERN_DEBUG "EXT4-fs: added group %u:"
1282 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count,
1283 blocks_count, free_blocks, reserved_blocks);
1284}
1285
Yongqiang Yang4bac1f82012-01-03 23:44:38 -05001286/* Add a flex group to an fs. Ensure we handle all possible error conditions
1287 * _before_ we start modifying the filesystem, because we cannot abort the
1288 * transaction and not have it write the data to disk.
1289 */
1290static int ext4_flex_group_add(struct super_block *sb,
1291 struct inode *resize_inode,
1292 struct ext4_new_flex_group_data *flex_gd)
1293{
1294 struct ext4_sb_info *sbi = EXT4_SB(sb);
1295 struct ext4_super_block *es = sbi->s_es;
1296 ext4_fsblk_t o_blocks_count;
1297 ext4_grpblk_t last;
1298 ext4_group_t group;
1299 handle_t *handle;
1300 unsigned reserved_gdb;
1301 int err = 0, err2 = 0, credit;
1302
1303 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags);
1304
1305 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks);
1306 o_blocks_count = ext4_blocks_count(es);
1307 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1308 BUG_ON(last);
1309
1310 err = setup_new_flex_group_blocks(sb, flex_gd);
1311 if (err)
1312 goto exit;
1313 /*
1314 * We will always be modifying at least the superblock and GDT
1315 * block. If we are adding a group past the last current GDT block,
1316 * we will also modify the inode and the dindirect block. If we
1317 * are adding a group with superblock/GDT backups we will also
1318 * modify each of the reserved GDT dindirect blocks.
1319 */
1320 credit = flex_gd->count * 4 + reserved_gdb;
1321 handle = ext4_journal_start_sb(sb, credit);
1322 if (IS_ERR(handle)) {
1323 err = PTR_ERR(handle);
1324 goto exit;
1325 }
1326
1327 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
1328 if (err)
1329 goto exit_journal;
1330
1331 group = flex_gd->groups[0].group;
1332 BUG_ON(group != EXT4_SB(sb)->s_groups_count);
1333 err = ext4_add_new_descs(handle, sb, group,
1334 resize_inode, flex_gd->count);
1335 if (err)
1336 goto exit_journal;
1337
1338 err = ext4_setup_new_descs(handle, sb, flex_gd);
1339 if (err)
1340 goto exit_journal;
1341
1342 ext4_update_super(sb, flex_gd);
1343
1344 err = ext4_handle_dirty_super(handle, sb);
1345
1346exit_journal:
1347 err2 = ext4_journal_stop(handle);
1348 if (!err)
1349 err = err2;
1350
1351 if (!err) {
1352 int i;
1353 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
1354 sizeof(struct ext4_super_block));
1355 for (i = 0; i < flex_gd->count; i++, group++) {
1356 struct buffer_head *gdb_bh;
1357 int gdb_num;
1358 gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
1359 gdb_bh = sbi->s_group_desc[gdb_num];
1360 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
1361 gdb_bh->b_size);
1362 }
1363 }
1364exit:
1365 return err;
1366}
1367
Yongqiang Yang19c52462012-01-04 17:09:44 -05001368static int ext4_setup_next_flex_gd(struct super_block *sb,
1369 struct ext4_new_flex_group_data *flex_gd,
1370 ext4_fsblk_t n_blocks_count,
1371 unsigned long flexbg_size)
1372{
1373 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1374 struct ext4_new_group_data *group_data = flex_gd->groups;
1375 ext4_fsblk_t o_blocks_count;
1376 ext4_group_t n_group;
1377 ext4_group_t group;
1378 ext4_group_t last_group;
1379 ext4_grpblk_t last;
1380 ext4_grpblk_t blocks_per_group;
1381 unsigned long i;
1382
1383 blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb);
1384
1385 o_blocks_count = ext4_blocks_count(es);
1386
1387 if (o_blocks_count == n_blocks_count)
1388 return 0;
1389
1390 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
1391 BUG_ON(last);
1392 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last);
1393
1394 last_group = group | (flexbg_size - 1);
1395 if (last_group > n_group)
1396 last_group = n_group;
1397
1398 flex_gd->count = last_group - group + 1;
1399
1400 for (i = 0; i < flex_gd->count; i++) {
1401 int overhead;
1402
1403 group_data[i].group = group + i;
1404 group_data[i].blocks_count = blocks_per_group;
1405 overhead = ext4_bg_has_super(sb, group + i) ?
1406 (1 + ext4_bg_num_gdb(sb, group + i) +
1407 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
1408 group_data[i].free_blocks_count = blocks_per_group - overhead;
Darrick J. Wongfeb0ab32012-04-29 18:45:10 -04001409 if (ext4_has_group_desc_csum(sb))
Yongqiang Yang19c52462012-01-04 17:09:44 -05001410 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT |
1411 EXT4_BG_INODE_UNINIT;
1412 else
1413 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED;
1414 }
1415
Darrick J. Wongfeb0ab32012-04-29 18:45:10 -04001416 if (last_group == n_group && ext4_has_group_desc_csum(sb))
Yongqiang Yang19c52462012-01-04 17:09:44 -05001417 /* We need to initialize block bitmap of last group. */
1418 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT;
1419
1420 if ((last_group == n_group) && (last != blocks_per_group - 1)) {
1421 group_data[i - 1].blocks_count = last + 1;
1422 group_data[i - 1].free_blocks_count -= blocks_per_group-
1423 last - 1;
1424 }
1425
1426 return 1;
1427}
1428
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001429/* Add group descriptor data to an existing or new group descriptor block.
1430 * Ensure we handle all possible error conditions _before_ we start modifying
1431 * the filesystem, because we cannot abort the transaction and not have it
1432 * write the data to disk.
1433 *
1434 * If we are on a GDT block boundary, we need to get the reserved GDT block.
1435 * Otherwise, we may need to add backup GDT blocks for a sparse group.
1436 *
1437 * We only need to hold the superblock lock while we are actually adding
1438 * in the new group's counts to the superblock. Prior to that we have
1439 * not really "added" the group at all. We re-check that we are still
1440 * adding in the last group in case things have changed since verifying.
1441 */
Mingming Cao617ba132006-10-11 01:20:53 -07001442int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001443{
Yongqiang Yang61f296c2012-01-04 17:09:50 -05001444 struct ext4_new_flex_group_data flex_gd;
Mingming Cao617ba132006-10-11 01:20:53 -07001445 struct ext4_sb_info *sbi = EXT4_SB(sb);
1446 struct ext4_super_block *es = sbi->s_es;
1447 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001448 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001449 struct inode *inode = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001450 int gdb_off, gdb_num;
Yongqiang Yang61f296c2012-01-04 17:09:50 -05001451 int err;
1452 __u16 bg_flags = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001453
Mingming Cao617ba132006-10-11 01:20:53 -07001454 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
1455 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001456
Mingming Cao617ba132006-10-11 01:20:53 -07001457 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
1458 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001459 ext4_warning(sb, "Can't resize non-sparse filesystem further");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001460 return -EPERM;
1461 }
1462
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001463 if (ext4_blocks_count(es) + input->blocks_count <
1464 ext4_blocks_count(es)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001465 ext4_warning(sb, "blocks_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001466 return -EINVAL;
1467 }
1468
Mingming Cao617ba132006-10-11 01:20:53 -07001469 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001470 le32_to_cpu(es->s_inodes_count)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001471 ext4_warning(sb, "inodes_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001472 return -EINVAL;
1473 }
1474
1475 if (reserved_gdb || gdb_off == 0) {
Mingming Cao617ba132006-10-11 01:20:53 -07001476 if (!EXT4_HAS_COMPAT_FEATURE(sb,
Josef Bacik37609fd2008-08-19 22:13:41 -04001477 EXT4_FEATURE_COMPAT_RESIZE_INODE)
1478 || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001479 ext4_warning(sb,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001480 "No reserved GDT blocks, can't resize");
1481 return -EPERM;
1482 }
David Howells1d1fe1e2008-02-07 00:15:37 -08001483 inode = ext4_iget(sb, EXT4_RESIZE_INO);
1484 if (IS_ERR(inode)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001485 ext4_warning(sb, "Error opening resize inode");
David Howells1d1fe1e2008-02-07 00:15:37 -08001486 return PTR_ERR(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001487 }
1488 }
1489
Aneesh Kumar K.V920313a2009-01-05 21:36:19 -05001490
Yongqiang Yang61f296c2012-01-04 17:09:50 -05001491 err = verify_group_input(sb, input);
Aneesh Kumar K.V08c3a812009-09-09 23:50:17 -04001492 if (err)
Yongqiang Yang61f296c2012-01-04 17:09:50 -05001493 goto out;
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04001494
Yongqiang Yang61f296c2012-01-04 17:09:50 -05001495 flex_gd.count = 1;
1496 flex_gd.groups = input;
1497 flex_gd.bg_flags = &bg_flags;
1498 err = ext4_flex_group_add(sb, inode, &flex_gd);
1499out:
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001500 iput(inode);
1501 return err;
Mingming Cao617ba132006-10-11 01:20:53 -07001502} /* ext4_group_add */
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001503
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001504/*
Yongqiang Yang18e31432012-01-03 23:18:50 -05001505 * extend a group without checking assuming that checking has been done.
1506 */
1507static int ext4_group_extend_no_check(struct super_block *sb,
1508 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add)
1509{
1510 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
1511 handle_t *handle;
1512 int err = 0, err2;
1513
1514 /* We will update the superblock, one block bitmap, and
1515 * one group descriptor via ext4_group_add_blocks().
1516 */
1517 handle = ext4_journal_start_sb(sb, 3);
1518 if (IS_ERR(handle)) {
1519 err = PTR_ERR(handle);
1520 ext4_warning(sb, "error %d on journal start", err);
1521 return err;
1522 }
1523
1524 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
1525 if (err) {
1526 ext4_warning(sb, "error %d on journal write access", err);
1527 goto errout;
1528 }
1529
1530 ext4_blocks_count_set(es, o_blocks_count + add);
Darrick J. Wong636d7e2e2012-03-20 15:46:11 -04001531 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add);
Yongqiang Yang18e31432012-01-03 23:18:50 -05001532 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
1533 o_blocks_count + add);
1534 /* We add the blocks to the bitmap and set the group need init bit */
1535 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add);
1536 if (err)
1537 goto errout;
1538 ext4_handle_dirty_super(handle, sb);
1539 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
1540 o_blocks_count + add);
1541errout:
1542 err2 = ext4_journal_stop(handle);
1543 if (err2 && !err)
1544 err = err2;
1545
1546 if (!err) {
1547 if (test_opt(sb, DEBUG))
1548 printk(KERN_DEBUG "EXT4-fs: extended group to %llu "
1549 "blocks\n", ext4_blocks_count(es));
1550 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
1551 sizeof(struct ext4_super_block));
1552 }
1553 return err;
1554}
1555
1556/*
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001557 * Extend the filesystem to the new number of blocks specified. This entry
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001558 * point is only used to extend the current filesystem to the end of the last
1559 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
1560 * for emergencies (because it has no dependencies on reserved blocks).
1561 *
Mingming Cao617ba132006-10-11 01:20:53 -07001562 * If we _really_ wanted, we could use default values to call ext4_group_add()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001563 * allow the "remount" trick to work for arbitrary resizing, assuming enough
1564 * GDT blocks are reserved to grow to the desired size.
1565 */
Mingming Cao617ba132006-10-11 01:20:53 -07001566int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
1567 ext4_fsblk_t n_blocks_count)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001568{
Mingming Cao617ba132006-10-11 01:20:53 -07001569 ext4_fsblk_t o_blocks_count;
Mingming Cao617ba132006-10-11 01:20:53 -07001570 ext4_grpblk_t last;
1571 ext4_grpblk_t add;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001572 struct buffer_head *bh;
Yongqiang Yangd89651c2012-01-04 17:09:48 -05001573 int err;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04001574 ext4_group_t group;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001575
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001576 o_blocks_count = ext4_blocks_count(es);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001577
1578 if (test_opt(sb, DEBUG))
Theodore Ts'o92b97812012-03-19 23:41:49 -04001579 ext4_msg(sb, KERN_DEBUG,
1580 "extending last group from %llu to %llu blocks",
1581 o_blocks_count, n_blocks_count);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001582
1583 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
1584 return 0;
1585
1586 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
Theodore Ts'o92b97812012-03-19 23:41:49 -04001587 ext4_msg(sb, KERN_ERR,
1588 "filesystem too large to resize to %llu blocks safely",
1589 n_blocks_count);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001590 if (sizeof(sector_t) < 8)
Eric Sandeen12062dd2010-02-15 14:19:27 -05001591 ext4_warning(sb, "CONFIG_LBDAF not enabled");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001592 return -EINVAL;
1593 }
1594
1595 if (n_blocks_count < o_blocks_count) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001596 ext4_warning(sb, "can't shrink FS - resize aborted");
Yongqiang Yang8f82f842011-07-26 21:35:44 -04001597 return -EINVAL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001598 }
1599
1600 /* Handle the remaining blocks in the last group only. */
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04001601 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001602
1603 if (last == 0) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001604 ext4_warning(sb, "need to use ext2online to resize further");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001605 return -EPERM;
1606 }
1607
Mingming Cao617ba132006-10-11 01:20:53 -07001608 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001609
1610 if (o_blocks_count + add < o_blocks_count) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001611 ext4_warning(sb, "blocks_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001612 return -EINVAL;
1613 }
1614
1615 if (o_blocks_count + add > n_blocks_count)
1616 add = n_blocks_count - o_blocks_count;
1617
1618 if (o_blocks_count + add < n_blocks_count)
Eric Sandeen12062dd2010-02-15 14:19:27 -05001619 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001620 o_blocks_count + add, add);
1621
1622 /* See if the device is actually as big as what was requested */
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001623 bh = sb_bread(sb, o_blocks_count + add - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001624 if (!bh) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001625 ext4_warning(sb, "can't read last block, resize aborted");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001626 return -ENOSPC;
1627 }
1628 brelse(bh);
1629
Yongqiang Yangd89651c2012-01-04 17:09:48 -05001630 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001631 return err;
Mingming Cao617ba132006-10-11 01:20:53 -07001632} /* ext4_group_extend */
Yongqiang Yang19c52462012-01-04 17:09:44 -05001633
1634/*
1635 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count
1636 *
1637 * @sb: super block of the fs to be resized
1638 * @n_blocks_count: the number of blocks resides in the resized fs
1639 */
1640int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count)
1641{
1642 struct ext4_new_flex_group_data *flex_gd = NULL;
1643 struct ext4_sb_info *sbi = EXT4_SB(sb);
1644 struct ext4_super_block *es = sbi->s_es;
1645 struct buffer_head *bh;
1646 struct inode *resize_inode;
1647 ext4_fsblk_t o_blocks_count;
1648 ext4_group_t o_group;
1649 ext4_group_t n_group;
Lukas Czernera0ade1d2012-02-20 23:02:06 -05001650 ext4_grpblk_t offset, add;
Yongqiang Yang19c52462012-01-04 17:09:44 -05001651 unsigned long n_desc_blocks;
1652 unsigned long o_desc_blocks;
1653 unsigned long desc_blocks;
1654 int err = 0, flexbg_size = 1;
1655
1656 o_blocks_count = ext4_blocks_count(es);
1657
1658 if (test_opt(sb, DEBUG))
Theodore Ts'o92b97812012-03-19 23:41:49 -04001659 ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu "
1660 "to %llu blocks", o_blocks_count, n_blocks_count);
Yongqiang Yang19c52462012-01-04 17:09:44 -05001661
1662 if (n_blocks_count < o_blocks_count) {
1663 /* On-line shrinking not supported */
1664 ext4_warning(sb, "can't shrink FS - resize aborted");
1665 return -EINVAL;
1666 }
1667
1668 if (n_blocks_count == o_blocks_count)
1669 /* Nothing need to do */
1670 return 0;
1671
1672 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset);
Lukas Czernera0ade1d2012-02-20 23:02:06 -05001673 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset);
Yongqiang Yang19c52462012-01-04 17:09:44 -05001674
1675 n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) /
1676 EXT4_DESC_PER_BLOCK(sb);
1677 o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
1678 EXT4_DESC_PER_BLOCK(sb);
1679 desc_blocks = n_desc_blocks - o_desc_blocks;
1680
1681 if (desc_blocks &&
1682 (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) ||
1683 le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) {
1684 ext4_warning(sb, "No reserved GDT blocks, can't resize");
1685 return -EPERM;
1686 }
1687
1688 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO);
1689 if (IS_ERR(resize_inode)) {
1690 ext4_warning(sb, "Error opening resize inode");
1691 return PTR_ERR(resize_inode);
1692 }
1693
1694 /* See if the device is actually as big as what was requested */
1695 bh = sb_bread(sb, n_blocks_count - 1);
1696 if (!bh) {
1697 ext4_warning(sb, "can't read last block, resize aborted");
1698 return -ENOSPC;
1699 }
1700 brelse(bh);
1701
Lukas Czernera0ade1d2012-02-20 23:02:06 -05001702 /* extend the last group */
1703 if (n_group == o_group)
1704 add = n_blocks_count - o_blocks_count;
1705 else
1706 add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1);
1707 if (add > 0) {
Yongqiang Yang19c52462012-01-04 17:09:44 -05001708 err = ext4_group_extend_no_check(sb, o_blocks_count, add);
1709 if (err)
1710 goto out;
1711 }
1712
1713 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
1714 es->s_log_groups_per_flex)
1715 flexbg_size = 1 << es->s_log_groups_per_flex;
1716
1717 o_blocks_count = ext4_blocks_count(es);
1718 if (o_blocks_count == n_blocks_count)
1719 goto out;
1720
1721 flex_gd = alloc_flex_gd(flexbg_size);
1722 if (flex_gd == NULL) {
1723 err = -ENOMEM;
1724 goto out;
1725 }
1726
1727 /* Add flex groups. Note that a regular group is a
1728 * flex group with 1 group.
1729 */
1730 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
1731 flexbg_size)) {
1732 ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
1733 err = ext4_flex_group_add(sb, resize_inode, flex_gd);
1734 if (unlikely(err))
1735 break;
1736 }
1737
1738out:
1739 if (flex_gd)
1740 free_flex_gd(flex_gd);
1741
1742 iput(resize_inode);
1743 if (test_opt(sb, DEBUG))
Theodore Ts'o92b97812012-03-19 23:41:49 -04001744 ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu "
1745 "upto %llu blocks", o_blocks_count, n_blocks_count);
Yongqiang Yang19c52462012-01-04 17:09:44 -05001746 return err;
1747}