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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
Mingming Caodab291a2006-10-11 01:21:01 -070014#include <linux/ext4_jbd2.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070015
16#include <linux/errno.h>
17#include <linux/slab.h>
18
Andreas Dilger717d50e2007-10-16 18:38:25 -040019#include "group.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070020
21#define outside(b, first, last) ((b) < (first) || (b) >= (last))
22#define inside(b, first, last) ((b) >= (first) && (b) < (last))
23
24static int verify_group_input(struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -070025 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070026{
Mingming Cao617ba132006-10-11 01:20:53 -070027 struct ext4_sb_info *sbi = EXT4_SB(sb);
28 struct ext4_super_block *es = sbi->s_es;
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070029 ext4_fsblk_t start = ext4_blocks_count(es);
Mingming Cao617ba132006-10-11 01:20:53 -070030 ext4_fsblk_t end = start + input->blocks_count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070031 unsigned group = input->group;
Mingming Cao617ba132006-10-11 01:20:53 -070032 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
33 unsigned overhead = ext4_bg_has_super(sb, group) ?
34 (1 + ext4_bg_num_gdb(sb, group) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -070035 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
Mingming Cao617ba132006-10-11 01:20:53 -070036 ext4_fsblk_t metaend = start + overhead;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070037 struct buffer_head *bh = NULL;
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070038 ext4_grpblk_t free_blocks_count, offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070039 int err = -EINVAL;
40
41 input->free_blocks_count = free_blocks_count =
42 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
43
44 if (test_opt(sb, DEBUG))
Mingming Cao617ba132006-10-11 01:20:53 -070045 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
Dave Kleikampac27a0e2006-10-11 01:20:50 -070046 "(%d free, %u reserved)\n",
Mingming Cao617ba132006-10-11 01:20:53 -070047 ext4_bg_has_super(sb, input->group) ? "normal" :
Dave Kleikampac27a0e2006-10-11 01:20:50 -070048 "no-super", input->group, input->blocks_count,
49 free_blocks_count, input->reserved_blocks);
50
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070051 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070052 if (group != sbi->s_groups_count)
Mingming Cao617ba132006-10-11 01:20:53 -070053 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070054 "Cannot add at group %u (only %lu groups)",
55 input->group, sbi->s_groups_count);
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070056 else if (offset != 0)
57 ext4_warning(sb, __FUNCTION__, "Last group not full");
Dave Kleikampac27a0e2006-10-11 01:20:50 -070058 else if (input->reserved_blocks > input->blocks_count / 5)
Mingming Cao617ba132006-10-11 01:20:53 -070059 ext4_warning(sb, __FUNCTION__, "Reserved blocks too high (%u)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070060 input->reserved_blocks);
61 else if (free_blocks_count < 0)
Mingming Cao617ba132006-10-11 01:20:53 -070062 ext4_warning(sb, __FUNCTION__, "Bad blocks count %u",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070063 input->blocks_count);
64 else if (!(bh = sb_bread(sb, end - 1)))
Mingming Cao617ba132006-10-11 01:20:53 -070065 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -070066 "Cannot read last block (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070067 end - 1);
68 else if (outside(input->block_bitmap, start, end))
Mingming Cao617ba132006-10-11 01:20:53 -070069 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070070 "Block bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070071 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070072 else if (outside(input->inode_bitmap, start, end))
Mingming Cao617ba132006-10-11 01:20:53 -070073 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070074 "Inode bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070075 (unsigned long long)input->inode_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070076 else if (outside(input->inode_table, start, end) ||
77 outside(itend - 1, start, end))
Mingming Cao617ba132006-10-11 01:20:53 -070078 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070079 "Inode table not in group (blocks %llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070080 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070081 else if (input->inode_bitmap == input->block_bitmap)
Mingming Cao617ba132006-10-11 01:20:53 -070082 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070083 "Block bitmap same as inode bitmap (%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070084 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070085 else if (inside(input->block_bitmap, input->inode_table, itend))
Mingming Cao617ba132006-10-11 01:20:53 -070086 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070087 "Block bitmap (%llu) in inode table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070088 (unsigned long long)input->block_bitmap,
89 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070090 else if (inside(input->inode_bitmap, input->inode_table, itend))
Mingming Cao617ba132006-10-11 01:20:53 -070091 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070092 "Inode bitmap (%llu) in inode table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070093 (unsigned long long)input->inode_bitmap,
94 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095 else if (inside(input->block_bitmap, start, metaend))
Mingming Cao617ba132006-10-11 01:20:53 -070096 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070097 "Block bitmap (%llu) in GDT table"
Mingming Cao2ae02102006-10-11 01:21:11 -070098 " (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070099 (unsigned long long)input->block_bitmap,
100 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700101 else if (inside(input->inode_bitmap, start, metaend))
Mingming Cao617ba132006-10-11 01:20:53 -0700102 ext4_warning(sb, __FUNCTION__,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700103 "Inode bitmap (%llu) in GDT table"
Mingming Cao2ae02102006-10-11 01:21:11 -0700104 " (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700105 (unsigned long long)input->inode_bitmap,
106 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700107 else if (inside(input->inode_table, start, metaend) ||
108 inside(itend - 1, start, metaend))
Mingming Cao617ba132006-10-11 01:20:53 -0700109 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700110 "Inode table (%llu-%llu) overlaps"
111 "GDT table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -0700112 (unsigned long long)input->inode_table,
113 itend - 1, start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700114 else
115 err = 0;
116 brelse(bh);
117
118 return err;
119}
120
121static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -0700122 ext4_fsblk_t blk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700123{
124 struct buffer_head *bh;
125 int err;
126
127 bh = sb_getblk(sb, blk);
128 if (!bh)
129 return ERR_PTR(-EIO);
Mingming Cao617ba132006-10-11 01:20:53 -0700130 if ((err = ext4_journal_get_write_access(handle, bh))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700131 brelse(bh);
132 bh = ERR_PTR(err);
133 } else {
134 lock_buffer(bh);
135 memset(bh->b_data, 0, sb->s_blocksize);
136 set_buffer_uptodate(bh);
137 unlock_buffer(bh);
138 }
139
140 return bh;
141}
142
143/*
Eric Sandeen14904102007-10-16 18:38:25 -0400144 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
145 * If that fails, restart the transaction & regain write access for the
146 * buffer head which is used for block_bitmap modifications.
147 */
148static int extend_or_restart_transaction(handle_t *handle, int thresh,
149 struct buffer_head *bh)
150{
151 int err;
152
153 if (handle->h_buffer_credits >= thresh)
154 return 0;
155
156 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
157 if (err < 0)
158 return err;
159 if (err) {
160 if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
161 return err;
162 if ((err = ext4_journal_get_write_access(handle, bh)))
163 return err;
164 }
165
166 return 0;
167}
168
169/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700170 * Set up the block and inode bitmaps, and the inode table for the new group.
171 * This doesn't need to be part of the main transaction, since we are only
172 * changing blocks outside the actual filesystem. We still do journaling to
173 * ensure the recovery is correct in case of a failure just after resize.
174 * If any part of this fails, we simply abort the resize.
175 */
176static int setup_new_group_blocks(struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -0700177 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700178{
Mingming Cao617ba132006-10-11 01:20:53 -0700179 struct ext4_sb_info *sbi = EXT4_SB(sb);
180 ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
181 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700182 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700183 unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700184 struct buffer_head *bh;
185 handle_t *handle;
Mingming Cao617ba132006-10-11 01:20:53 -0700186 ext4_fsblk_t block;
187 ext4_grpblk_t bit;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700188 int i;
189 int err = 0, err2;
190
Eric Sandeen14904102007-10-16 18:38:25 -0400191 /* This transaction may be extended/restarted along the way */
192 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
193
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700194 if (IS_ERR(handle))
195 return PTR_ERR(handle);
196
197 lock_super(sb);
198 if (input->group != sbi->s_groups_count) {
199 err = -EBUSY;
200 goto exit_journal;
201 }
202
203 if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
204 err = PTR_ERR(bh);
205 goto exit_journal;
206 }
207
Mingming Cao617ba132006-10-11 01:20:53 -0700208 if (ext4_bg_has_super(sb, input->group)) {
209 ext4_debug("mark backup superblock %#04lx (+0)\n", start);
210 ext4_set_bit(0, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700211 }
212
213 /* Copy all of the GDT blocks into the backup in this group */
214 for (i = 0, bit = 1, block = start + 1;
215 i < gdblocks; i++, block++, bit++) {
216 struct buffer_head *gdb;
217
Mingming Cao617ba132006-10-11 01:20:53 -0700218 ext4_debug("update backup group %#04lx (+%d)\n", block, bit);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700219
Eric Sandeen14904102007-10-16 18:38:25 -0400220 if ((err = extend_or_restart_transaction(handle, 1, bh)))
221 goto exit_bh;
222
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700223 gdb = sb_getblk(sb, block);
224 if (!gdb) {
225 err = -EIO;
226 goto exit_bh;
227 }
Mingming Cao617ba132006-10-11 01:20:53 -0700228 if ((err = ext4_journal_get_write_access(handle, gdb))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700229 brelse(gdb);
230 goto exit_bh;
231 }
Eric Sandeen5b615282007-10-16 18:38:25 -0400232 lock_buffer(gdb);
233 memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700234 set_buffer_uptodate(gdb);
Eric Sandeen5b615282007-10-16 18:38:25 -0400235 unlock_buffer(gdb);
Mingming Cao617ba132006-10-11 01:20:53 -0700236 ext4_journal_dirty_metadata(handle, gdb);
237 ext4_set_bit(bit, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700238 brelse(gdb);
239 }
240
241 /* Zero out all of the reserved backup group descriptor table blocks */
242 for (i = 0, bit = gdblocks + 1, block = start + bit;
243 i < reserved_gdb; i++, block++, bit++) {
244 struct buffer_head *gdb;
245
Mingming Cao617ba132006-10-11 01:20:53 -0700246 ext4_debug("clear reserved block %#04lx (+%d)\n", block, bit);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700247
Eric Sandeen14904102007-10-16 18:38:25 -0400248 if ((err = extend_or_restart_transaction(handle, 1, bh)))
249 goto exit_bh;
250
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700251 if (IS_ERR(gdb = bclean(handle, sb, block))) {
252 err = PTR_ERR(bh);
253 goto exit_bh;
254 }
Mingming Cao617ba132006-10-11 01:20:53 -0700255 ext4_journal_dirty_metadata(handle, gdb);
256 ext4_set_bit(bit, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700257 brelse(gdb);
258 }
Mingming Cao617ba132006-10-11 01:20:53 -0700259 ext4_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700260 input->block_bitmap - start);
Mingming Cao617ba132006-10-11 01:20:53 -0700261 ext4_set_bit(input->block_bitmap - start, bh->b_data);
262 ext4_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700263 input->inode_bitmap - start);
Mingming Cao617ba132006-10-11 01:20:53 -0700264 ext4_set_bit(input->inode_bitmap - start, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700265
266 /* Zero out all of the inode table blocks */
267 for (i = 0, block = input->inode_table, bit = block - start;
268 i < sbi->s_itb_per_group; i++, bit++, block++) {
269 struct buffer_head *it;
270
Mingming Cao617ba132006-10-11 01:20:53 -0700271 ext4_debug("clear inode block %#04lx (+%d)\n", block, bit);
Eric Sandeen14904102007-10-16 18:38:25 -0400272
273 if ((err = extend_or_restart_transaction(handle, 1, bh)))
274 goto exit_bh;
275
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700276 if (IS_ERR(it = bclean(handle, sb, block))) {
277 err = PTR_ERR(it);
278 goto exit_bh;
279 }
Mingming Cao617ba132006-10-11 01:20:53 -0700280 ext4_journal_dirty_metadata(handle, it);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700281 brelse(it);
Mingming Cao617ba132006-10-11 01:20:53 -0700282 ext4_set_bit(bit, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700283 }
Eric Sandeen14904102007-10-16 18:38:25 -0400284
285 if ((err = extend_or_restart_transaction(handle, 2, bh)))
286 goto exit_bh;
287
Mingming Cao617ba132006-10-11 01:20:53 -0700288 mark_bitmap_end(input->blocks_count, EXT4_BLOCKS_PER_GROUP(sb),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700289 bh->b_data);
Mingming Cao617ba132006-10-11 01:20:53 -0700290 ext4_journal_dirty_metadata(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700291 brelse(bh);
292
293 /* Mark unused entries in inode bitmap used */
Mingming Cao617ba132006-10-11 01:20:53 -0700294 ext4_debug("clear inode bitmap %#04x (+%ld)\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700295 input->inode_bitmap, input->inode_bitmap - start);
296 if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
297 err = PTR_ERR(bh);
298 goto exit_journal;
299 }
300
Mingming Cao617ba132006-10-11 01:20:53 -0700301 mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), EXT4_BLOCKS_PER_GROUP(sb),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700302 bh->b_data);
Mingming Cao617ba132006-10-11 01:20:53 -0700303 ext4_journal_dirty_metadata(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700304exit_bh:
305 brelse(bh);
306
307exit_journal:
308 unlock_super(sb);
Mingming Cao617ba132006-10-11 01:20:53 -0700309 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700310 err = err2;
311
312 return err;
313}
314
315/*
316 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
Mingming Cao617ba132006-10-11 01:20:53 -0700317 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700318 * calling this for the first time. In a sparse filesystem it will be the
319 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
320 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
321 */
Mingming Cao617ba132006-10-11 01:20:53 -0700322static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700323 unsigned *five, unsigned *seven)
324{
325 unsigned *min = three;
326 int mult = 3;
327 unsigned ret;
328
Mingming Cao617ba132006-10-11 01:20:53 -0700329 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
330 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700331 ret = *min;
332 *min += 1;
333 return ret;
334 }
335
336 if (*five < *min) {
337 min = five;
338 mult = 5;
339 }
340 if (*seven < *min) {
341 min = seven;
342 mult = 7;
343 }
344
345 ret = *min;
346 *min *= mult;
347
348 return ret;
349}
350
351/*
352 * Check that all of the backup GDT blocks are held in the primary GDT block.
353 * It is assumed that they are stored in group order. Returns the number of
354 * groups in current filesystem that have BACKUPS, or -ve error code.
355 */
356static int verify_reserved_gdb(struct super_block *sb,
357 struct buffer_head *primary)
358{
Mingming Cao617ba132006-10-11 01:20:53 -0700359 const ext4_fsblk_t blk = primary->b_blocknr;
360 const unsigned long end = EXT4_SB(sb)->s_groups_count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700361 unsigned three = 1;
362 unsigned five = 5;
363 unsigned seven = 7;
364 unsigned grp;
365 __le32 *p = (__le32 *)primary->b_data;
366 int gdbackups = 0;
367
Mingming Cao617ba132006-10-11 01:20:53 -0700368 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700369 if (le32_to_cpu(*p++) !=
370 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
Mingming Cao617ba132006-10-11 01:20:53 -0700371 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700372 "reserved GDT %llu"
373 " missing grp %d (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700374 blk, grp,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700375 grp *
376 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
377 blk);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700378 return -EINVAL;
379 }
Mingming Cao617ba132006-10-11 01:20:53 -0700380 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700381 return -EFBIG;
382 }
383
384 return gdbackups;
385}
386
387/*
388 * Called when we need to bring a reserved group descriptor table block into
389 * use from the resize inode. The primary copy of the new GDT block currently
390 * is an indirect block (under the double indirect block in the resize inode).
391 * The new backup GDT blocks will be stored as leaf blocks in this indirect
392 * block, in group order. Even though we know all the block numbers we need,
393 * we check to ensure that the resize inode has actually reserved these blocks.
394 *
395 * Don't need to update the block bitmaps because the blocks are still in use.
396 *
397 * We get all of the error cases out of the way, so that we are sure to not
398 * fail once we start modifying the data on disk, because JBD has no rollback.
399 */
400static int add_new_gdb(handle_t *handle, struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -0700401 struct ext4_new_group_data *input,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700402 struct buffer_head **primary)
403{
404 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700405 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
406 unsigned long gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
407 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700408 struct buffer_head **o_group_desc, **n_group_desc;
409 struct buffer_head *dind;
410 int gdbackups;
Mingming Cao617ba132006-10-11 01:20:53 -0700411 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700412 __le32 *data;
413 int err;
414
415 if (test_opt(sb, DEBUG))
416 printk(KERN_DEBUG
Mingming Cao617ba132006-10-11 01:20:53 -0700417 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700418 gdb_num);
419
420 /*
421 * If we are not using the primary superblock/GDT copy don't resize,
422 * because the user tools have no way of handling this. Probably a
423 * bad time to do it anyways.
424 */
Mingming Cao617ba132006-10-11 01:20:53 -0700425 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
426 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
427 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700428 "won't resize using backup superblock at %llu",
Mingming Cao617ba132006-10-11 01:20:53 -0700429 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700430 return -EPERM;
431 }
432
433 *primary = sb_bread(sb, gdblock);
434 if (!*primary)
435 return -EIO;
436
437 if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) {
438 err = gdbackups;
439 goto exit_bh;
440 }
441
Mingming Cao617ba132006-10-11 01:20:53 -0700442 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700443 dind = sb_bread(sb, le32_to_cpu(*data));
444 if (!dind) {
445 err = -EIO;
446 goto exit_bh;
447 }
448
449 data = (__le32 *)dind->b_data;
Mingming Cao617ba132006-10-11 01:20:53 -0700450 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
451 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700452 "new group %u GDT block %llu not reserved",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700453 input->group, gdblock);
454 err = -EINVAL;
455 goto exit_dind;
456 }
457
Mingming Cao617ba132006-10-11 01:20:53 -0700458 if ((err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459 goto exit_dind;
460
Mingming Cao617ba132006-10-11 01:20:53 -0700461 if ((err = ext4_journal_get_write_access(handle, *primary)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700462 goto exit_sbh;
463
Mingming Cao617ba132006-10-11 01:20:53 -0700464 if ((err = ext4_journal_get_write_access(handle, dind)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700465 goto exit_primary;
466
Mingming Cao617ba132006-10-11 01:20:53 -0700467 /* ext4_reserve_inode_write() gets a reference on the iloc */
468 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700469 goto exit_dindj;
470
471 n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
472 GFP_KERNEL);
473 if (!n_group_desc) {
474 err = -ENOMEM;
Mingming Cao617ba132006-10-11 01:20:53 -0700475 ext4_warning (sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700476 "not enough memory for %lu groups", gdb_num + 1);
477 goto exit_inode;
478 }
479
480 /*
481 * Finally, we have all of the possible failures behind us...
482 *
483 * Remove new GDT block from inode double-indirect block and clear out
484 * the new GDT block for use (which also "frees" the backup GDT blocks
485 * from the reserved inode). We don't need to change the bitmaps for
486 * these blocks, because they are marked as in-use from being in the
487 * reserved inode, and will become GDT blocks (primary and backup).
488 */
Mingming Cao617ba132006-10-11 01:20:53 -0700489 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
490 ext4_journal_dirty_metadata(handle, dind);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700491 brelse(dind);
492 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700493 ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700494 memset((*primary)->b_data, 0, sb->s_blocksize);
Mingming Cao617ba132006-10-11 01:20:53 -0700495 ext4_journal_dirty_metadata(handle, *primary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700496
Mingming Cao617ba132006-10-11 01:20:53 -0700497 o_group_desc = EXT4_SB(sb)->s_group_desc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700498 memcpy(n_group_desc, o_group_desc,
Mingming Cao617ba132006-10-11 01:20:53 -0700499 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700500 n_group_desc[gdb_num] = *primary;
Mingming Cao617ba132006-10-11 01:20:53 -0700501 EXT4_SB(sb)->s_group_desc = n_group_desc;
502 EXT4_SB(sb)->s_gdb_count++;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700503 kfree(o_group_desc);
504
505 es->s_reserved_gdt_blocks =
506 cpu_to_le16(le16_to_cpu(es->s_reserved_gdt_blocks) - 1);
Mingming Cao617ba132006-10-11 01:20:53 -0700507 ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700508
509 return 0;
510
511exit_inode:
Mingming Cao617ba132006-10-11 01:20:53 -0700512 //ext4_journal_release_buffer(handle, iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700513 brelse(iloc.bh);
514exit_dindj:
Mingming Cao617ba132006-10-11 01:20:53 -0700515 //ext4_journal_release_buffer(handle, dind);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700516exit_primary:
Mingming Cao617ba132006-10-11 01:20:53 -0700517 //ext4_journal_release_buffer(handle, *primary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700518exit_sbh:
Mingming Cao617ba132006-10-11 01:20:53 -0700519 //ext4_journal_release_buffer(handle, *primary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700520exit_dind:
521 brelse(dind);
522exit_bh:
523 brelse(*primary);
524
Mingming Cao617ba132006-10-11 01:20:53 -0700525 ext4_debug("leaving with error %d\n", err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700526 return err;
527}
528
529/*
530 * Called when we are adding a new group which has a backup copy of each of
531 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
532 * We need to add these reserved backup GDT blocks to the resize inode, so
533 * that they are kept for future resizing and not allocated to files.
534 *
535 * Each reserved backup GDT block will go into a different indirect block.
536 * The indirect blocks are actually the primary reserved GDT blocks,
537 * so we know in advance what their block numbers are. We only get the
538 * double-indirect block to verify it is pointing to the primary reserved
539 * GDT blocks so we don't overwrite a data block by accident. The reserved
540 * backup GDT blocks are stored in their reserved primary GDT block.
541 */
542static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -0700543 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700544{
545 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700546 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 struct buffer_head **primary;
548 struct buffer_head *dind;
Mingming Cao617ba132006-10-11 01:20:53 -0700549 struct ext4_iloc iloc;
550 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700551 __le32 *data, *end;
552 int gdbackups = 0;
553 int res, i;
554 int err;
555
556 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_KERNEL);
557 if (!primary)
558 return -ENOMEM;
559
Mingming Cao617ba132006-10-11 01:20:53 -0700560 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700561 dind = sb_bread(sb, le32_to_cpu(*data));
562 if (!dind) {
563 err = -EIO;
564 goto exit_free;
565 }
566
Mingming Cao617ba132006-10-11 01:20:53 -0700567 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
568 data = (__le32 *)dind->b_data + EXT4_SB(sb)->s_gdb_count;
569 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700570
571 /* Get each reserved primary GDT block and verify it holds backups */
572 for (res = 0; res < reserved_gdb; res++, blk++) {
573 if (le32_to_cpu(*data) != blk) {
Mingming Cao617ba132006-10-11 01:20:53 -0700574 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700575 "reserved block %llu"
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700576 " not at offset %ld",
577 blk,
578 (long)(data - (__le32 *)dind->b_data));
579 err = -EINVAL;
580 goto exit_bh;
581 }
582 primary[res] = sb_bread(sb, blk);
583 if (!primary[res]) {
584 err = -EIO;
585 goto exit_bh;
586 }
587 if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
588 brelse(primary[res]);
589 err = gdbackups;
590 goto exit_bh;
591 }
592 if (++data >= end)
593 data = (__le32 *)dind->b_data;
594 }
595
596 for (i = 0; i < reserved_gdb; i++) {
Mingming Cao617ba132006-10-11 01:20:53 -0700597 if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700598 /*
599 int j;
600 for (j = 0; j < i; j++)
Mingming Cao617ba132006-10-11 01:20:53 -0700601 ext4_journal_release_buffer(handle, primary[j]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700602 */
603 goto exit_bh;
604 }
605 }
606
Mingming Cao617ba132006-10-11 01:20:53 -0700607 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700608 goto exit_bh;
609
610 /*
611 * Finally we can add each of the reserved backup GDT blocks from
612 * the new group to its reserved primary GDT block.
613 */
Mingming Cao617ba132006-10-11 01:20:53 -0700614 blk = input->group * EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700615 for (i = 0; i < reserved_gdb; i++) {
616 int err2;
617 data = (__le32 *)primary[i]->b_data;
618 /* printk("reserving backup %lu[%u] = %lu\n",
619 primary[i]->b_blocknr, gdbackups,
620 blk + primary[i]->b_blocknr); */
621 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
Mingming Cao617ba132006-10-11 01:20:53 -0700622 err2 = ext4_journal_dirty_metadata(handle, primary[i]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700623 if (!err)
624 err = err2;
625 }
626 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700627 ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700628
629exit_bh:
630 while (--res >= 0)
631 brelse(primary[res]);
632 brelse(dind);
633
634exit_free:
635 kfree(primary);
636
637 return err;
638}
639
640/*
Mingming Cao617ba132006-10-11 01:20:53 -0700641 * Update the backup copies of the ext4 metadata. These don't need to be part
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700642 * of the main resize transaction, because e2fsck will re-write them if there
643 * is a problem (basically only OOM will cause a problem). However, we
644 * _should_ update the backups if possible, in case the primary gets trashed
645 * for some reason and we need to run e2fsck from a backup superblock. The
646 * important part is that the new block and inode counts are in the backup
647 * superblocks, and the location of the new group metadata in the GDT backups.
648 *
649 * We do not need lock_super() for this, because these blocks are not
650 * otherwise touched by the filesystem code when it is mounted. We don't
651 * need to worry about last changing from sbi->s_groups_count, because the
652 * worst that can happen is that we do not copy the full number of backups
653 * at this time. The resize which changed s_groups_count will backup again.
654 */
655static void update_backups(struct super_block *sb,
656 int blk_off, char *data, int size)
657{
Mingming Cao617ba132006-10-11 01:20:53 -0700658 struct ext4_sb_info *sbi = EXT4_SB(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700659 const unsigned long last = sbi->s_groups_count;
Mingming Cao617ba132006-10-11 01:20:53 -0700660 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700661 unsigned three = 1;
662 unsigned five = 5;
663 unsigned seven = 7;
664 unsigned group;
665 int rest = sb->s_blocksize - size;
666 handle_t *handle;
667 int err = 0, err2;
668
Mingming Cao617ba132006-10-11 01:20:53 -0700669 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700670 if (IS_ERR(handle)) {
671 group = 1;
672 err = PTR_ERR(handle);
673 goto exit_err;
674 }
675
Mingming Cao617ba132006-10-11 01:20:53 -0700676 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700677 struct buffer_head *bh;
678
679 /* Out of journal space, and can't get more - abort - so sad */
680 if (handle->h_buffer_credits == 0 &&
Mingming Cao617ba132006-10-11 01:20:53 -0700681 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
682 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700683 break;
684
685 bh = sb_getblk(sb, group * bpg + blk_off);
686 if (!bh) {
687 err = -EIO;
688 break;
689 }
Mingming Cao617ba132006-10-11 01:20:53 -0700690 ext4_debug("update metadata backup %#04lx\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700691 (unsigned long)bh->b_blocknr);
Mingming Cao617ba132006-10-11 01:20:53 -0700692 if ((err = ext4_journal_get_write_access(handle, bh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700693 break;
694 lock_buffer(bh);
695 memcpy(bh->b_data, data, size);
696 if (rest)
697 memset(bh->b_data + size, 0, rest);
698 set_buffer_uptodate(bh);
699 unlock_buffer(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700700 ext4_journal_dirty_metadata(handle, bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700701 brelse(bh);
702 }
Mingming Cao617ba132006-10-11 01:20:53 -0700703 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700704 err = err2;
705
706 /*
707 * Ugh! Need to have e2fsck write the backup copies. It is too
708 * late to revert the resize, we shouldn't fail just because of
709 * the backup copies (they are only needed in case of corruption).
710 *
711 * However, if we got here we have a journal problem too, so we
712 * can't really start a transaction to mark the superblock.
713 * Chicken out and just set the flag on the hope it will be written
714 * to disk, and if not - we will simply wait until next fsck.
715 */
716exit_err:
717 if (err) {
Mingming Cao617ba132006-10-11 01:20:53 -0700718 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700719 "can't update backup for group %d (err %d), "
720 "forcing fsck on next reboot", group, err);
Mingming Cao617ba132006-10-11 01:20:53 -0700721 sbi->s_mount_state &= ~EXT4_VALID_FS;
722 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700723 mark_buffer_dirty(sbi->s_sbh);
724 }
725}
726
727/* Add group descriptor data to an existing or new group descriptor block.
728 * Ensure we handle all possible error conditions _before_ we start modifying
729 * the filesystem, because we cannot abort the transaction and not have it
730 * write the data to disk.
731 *
732 * If we are on a GDT block boundary, we need to get the reserved GDT block.
733 * Otherwise, we may need to add backup GDT blocks for a sparse group.
734 *
735 * We only need to hold the superblock lock while we are actually adding
736 * in the new group's counts to the superblock. Prior to that we have
737 * not really "added" the group at all. We re-check that we are still
738 * adding in the last group in case things have changed since verifying.
739 */
Mingming Cao617ba132006-10-11 01:20:53 -0700740int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700741{
Mingming Cao617ba132006-10-11 01:20:53 -0700742 struct ext4_sb_info *sbi = EXT4_SB(sb);
743 struct ext4_super_block *es = sbi->s_es;
744 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700745 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
746 struct buffer_head *primary = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700747 struct ext4_group_desc *gdp;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700748 struct inode *inode = NULL;
749 handle_t *handle;
750 int gdb_off, gdb_num;
751 int err, err2;
752
Mingming Cao617ba132006-10-11 01:20:53 -0700753 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
754 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700755
Mingming Cao617ba132006-10-11 01:20:53 -0700756 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
757 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
758 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700759 "Can't resize non-sparse filesystem further");
760 return -EPERM;
761 }
762
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700763 if (ext4_blocks_count(es) + input->blocks_count <
764 ext4_blocks_count(es)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700765 ext4_warning(sb, __FUNCTION__, "blocks_count overflow\n");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700766 return -EINVAL;
767 }
768
Mingming Cao617ba132006-10-11 01:20:53 -0700769 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700770 le32_to_cpu(es->s_inodes_count)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700771 ext4_warning(sb, __FUNCTION__, "inodes_count overflow\n");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700772 return -EINVAL;
773 }
774
775 if (reserved_gdb || gdb_off == 0) {
Mingming Cao617ba132006-10-11 01:20:53 -0700776 if (!EXT4_HAS_COMPAT_FEATURE(sb,
777 EXT4_FEATURE_COMPAT_RESIZE_INODE)){
778 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700779 "No reserved GDT blocks, can't resize");
780 return -EPERM;
781 }
Mingming Cao617ba132006-10-11 01:20:53 -0700782 inode = iget(sb, EXT4_RESIZE_INO);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700783 if (!inode || is_bad_inode(inode)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700784 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700785 "Error opening resize inode");
786 iput(inode);
787 return -ENOENT;
788 }
789 }
790
791 if ((err = verify_group_input(sb, input)))
792 goto exit_put;
793
794 if ((err = setup_new_group_blocks(sb, input)))
795 goto exit_put;
796
797 /*
798 * We will always be modifying at least the superblock and a GDT
799 * block. If we are adding a group past the last current GDT block,
800 * we will also modify the inode and the dindirect block. If we
801 * are adding a group with superblock/GDT backups we will also
802 * modify each of the reserved GDT dindirect blocks.
803 */
Mingming Cao617ba132006-10-11 01:20:53 -0700804 handle = ext4_journal_start_sb(sb,
805 ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700806 3 + reserved_gdb : 4);
807 if (IS_ERR(handle)) {
808 err = PTR_ERR(handle);
809 goto exit_put;
810 }
811
812 lock_super(sb);
813 if (input->group != sbi->s_groups_count) {
Mingming Cao617ba132006-10-11 01:20:53 -0700814 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700815 "multiple resizers run on filesystem!");
816 err = -EBUSY;
817 goto exit_journal;
818 }
819
Mingming Cao617ba132006-10-11 01:20:53 -0700820 if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700821 goto exit_journal;
822
823 /*
824 * We will only either add reserved group blocks to a backup group
825 * or remove reserved blocks for the first group in a new group block.
826 * Doing both would be mean more complex code, and sane people don't
827 * use non-sparse filesystems anymore. This is already checked above.
828 */
829 if (gdb_off) {
830 primary = sbi->s_group_desc[gdb_num];
Mingming Cao617ba132006-10-11 01:20:53 -0700831 if ((err = ext4_journal_get_write_access(handle, primary)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700832 goto exit_journal;
833
Mingming Cao617ba132006-10-11 01:20:53 -0700834 if (reserved_gdb && ext4_bg_num_gdb(sb, input->group) &&
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700835 (err = reserve_backup_gdb(handle, inode, input)))
836 goto exit_journal;
837 } else if ((err = add_new_gdb(handle, inode, input, &primary)))
838 goto exit_journal;
839
840 /*
841 * OK, now we've set up the new group. Time to make it active.
842 *
843 * Current kernels don't lock all allocations via lock_super(),
844 * so we have to be safe wrt. concurrent accesses the group
845 * data. So we need to be careful to set all of the relevant
846 * group descriptor data etc. *before* we enable the group.
847 *
848 * The key field here is sbi->s_groups_count: as long as
849 * that retains its old value, nobody is going to access the new
850 * group.
851 *
852 * So first we update all the descriptor metadata for the new
853 * group; then we update the total disk blocks count; then we
854 * update the groups count to enable the group; then finally we
855 * update the free space counts so that the system can start
856 * using the new disk blocks.
857 */
858
859 /* Update group descriptor block for new group */
Mingming Cao617ba132006-10-11 01:20:53 -0700860 gdp = (struct ext4_group_desc *)primary->b_data + gdb_off;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700861
Alexandre Ratchov8fadc142006-10-11 01:21:15 -0700862 ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
863 ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
864 ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700865 gdp->bg_free_blocks_count = cpu_to_le16(input->free_blocks_count);
Mingming Cao617ba132006-10-11 01:20:53 -0700866 gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb));
Andreas Dilger717d50e2007-10-16 18:38:25 -0400867 gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700868
869 /*
870 * Make the new blocks and inodes valid next. We do this before
871 * increasing the group count so that once the group is enabled,
872 * all of its blocks and inodes are already valid.
873 *
874 * We always allocate group-by-group, then block-by-block or
875 * inode-by-inode within a group, so enabling these
876 * blocks/inodes before the group is live won't actually let us
877 * allocate the new space yet.
878 */
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700879 ext4_blocks_count_set(es, ext4_blocks_count(es) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700880 input->blocks_count);
881 es->s_inodes_count = cpu_to_le32(le32_to_cpu(es->s_inodes_count) +
Mingming Cao617ba132006-10-11 01:20:53 -0700882 EXT4_INODES_PER_GROUP(sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700883
884 /*
885 * We need to protect s_groups_count against other CPUs seeing
886 * inconsistent state in the superblock.
887 *
888 * The precise rules we use are:
889 *
890 * * Writers of s_groups_count *must* hold lock_super
891 * AND
892 * * Writers must perform a smp_wmb() after updating all dependent
893 * data and before modifying the groups count
894 *
895 * * Readers must hold lock_super() over the access
896 * OR
897 * * Readers must perform an smp_rmb() after reading the groups count
898 * and before reading any dependent data.
899 *
900 * NB. These rules can be relaxed when checking the group count
901 * while freeing data, as we can only allocate from a block
902 * group after serialising against the group count, and we can
903 * only then free after serialising in turn against that
904 * allocation.
905 */
906 smp_wmb();
907
908 /* Update the global fs size fields */
909 sbi->s_groups_count++;
910
Mingming Cao617ba132006-10-11 01:20:53 -0700911 ext4_journal_dirty_metadata(handle, primary);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700912
913 /* Update the reserved block counts only once the new group is
914 * active. */
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700915 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700916 input->reserved_blocks);
917
918 /* Update the free space counts */
Peter Zijlstraaa0dff22007-10-16 23:25:42 -0700919 percpu_counter_add(&sbi->s_freeblocks_counter,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700920 input->free_blocks_count);
Peter Zijlstraaa0dff22007-10-16 23:25:42 -0700921 percpu_counter_add(&sbi->s_freeinodes_counter,
Mingming Cao617ba132006-10-11 01:20:53 -0700922 EXT4_INODES_PER_GROUP(sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700923
Mingming Cao617ba132006-10-11 01:20:53 -0700924 ext4_journal_dirty_metadata(handle, sbi->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700925 sb->s_dirt = 1;
926
927exit_journal:
928 unlock_super(sb);
Mingming Cao617ba132006-10-11 01:20:53 -0700929 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700930 err = err2;
931 if (!err) {
932 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
Mingming Cao617ba132006-10-11 01:20:53 -0700933 sizeof(struct ext4_super_block));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700934 update_backups(sb, primary->b_blocknr, primary->b_data,
935 primary->b_size);
936 }
937exit_put:
938 iput(inode);
939 return err;
Mingming Cao617ba132006-10-11 01:20:53 -0700940} /* ext4_group_add */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700941
942/* Extend the filesystem to the new number of blocks specified. This entry
943 * point is only used to extend the current filesystem to the end of the last
944 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
945 * for emergencies (because it has no dependencies on reserved blocks).
946 *
Mingming Cao617ba132006-10-11 01:20:53 -0700947 * If we _really_ wanted, we could use default values to call ext4_group_add()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700948 * allow the "remount" trick to work for arbitrary resizing, assuming enough
949 * GDT blocks are reserved to grow to the desired size.
950 */
Mingming Cao617ba132006-10-11 01:20:53 -0700951int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
952 ext4_fsblk_t n_blocks_count)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700953{
Mingming Cao617ba132006-10-11 01:20:53 -0700954 ext4_fsblk_t o_blocks_count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700955 unsigned long o_groups_count;
Mingming Cao617ba132006-10-11 01:20:53 -0700956 ext4_grpblk_t last;
957 ext4_grpblk_t add;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700958 struct buffer_head * bh;
959 handle_t *handle;
960 int err;
961 unsigned long freed_blocks;
962
963 /* We don't need to worry about locking wrt other resizers just
964 * yet: we're going to revalidate es->s_blocks_count after
965 * taking lock_super() below. */
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700966 o_blocks_count = ext4_blocks_count(es);
Mingming Cao617ba132006-10-11 01:20:53 -0700967 o_groups_count = EXT4_SB(sb)->s_groups_count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700968
969 if (test_opt(sb, DEBUG))
Mingming Cao2ae02102006-10-11 01:21:11 -0700970 printk(KERN_DEBUG "EXT4-fs: extending last group from %llu uto %llu blocks\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700971 o_blocks_count, n_blocks_count);
972
973 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
974 return 0;
975
976 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700977 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
Mingming Cao2ae02102006-10-11 01:21:11 -0700978 " too large to resize to %llu blocks safely\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700979 sb->s_id, n_blocks_count);
980 if (sizeof(sector_t) < 8)
Mingming Cao617ba132006-10-11 01:20:53 -0700981 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700982 "CONFIG_LBD not enabled\n");
983 return -EINVAL;
984 }
985
986 if (n_blocks_count < o_blocks_count) {
Mingming Cao617ba132006-10-11 01:20:53 -0700987 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700988 "can't shrink FS - resize aborted");
989 return -EBUSY;
990 }
991
992 /* Handle the remaining blocks in the last group only. */
Mingming Cao3a5b2ec2006-10-11 01:21:05 -0700993 ext4_get_group_no_and_offset(sb, o_blocks_count, NULL, &last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700994
995 if (last == 0) {
Mingming Cao617ba132006-10-11 01:20:53 -0700996 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700997 "need to use ext2online to resize further");
998 return -EPERM;
999 }
1000
Mingming Cao617ba132006-10-11 01:20:53 -07001001 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001002
1003 if (o_blocks_count + add < o_blocks_count) {
Mingming Cao617ba132006-10-11 01:20:53 -07001004 ext4_warning(sb, __FUNCTION__, "blocks_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001005 return -EINVAL;
1006 }
1007
1008 if (o_blocks_count + add > n_blocks_count)
1009 add = n_blocks_count - o_blocks_count;
1010
1011 if (o_blocks_count + add < n_blocks_count)
Mingming Cao617ba132006-10-11 01:20:53 -07001012 ext4_warning(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -07001013 "will only finish group (%llu"
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001014 " blocks, %u new)",
1015 o_blocks_count + add, add);
1016
1017 /* See if the device is actually as big as what was requested */
1018 bh = sb_bread(sb, o_blocks_count + add -1);
1019 if (!bh) {
Mingming Cao617ba132006-10-11 01:20:53 -07001020 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001021 "can't read last block, resize aborted");
1022 return -ENOSPC;
1023 }
1024 brelse(bh);
1025
1026 /* We will update the superblock, one block bitmap, and
Mingming Cao617ba132006-10-11 01:20:53 -07001027 * one group descriptor via ext4_free_blocks().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001028 */
Mingming Cao617ba132006-10-11 01:20:53 -07001029 handle = ext4_journal_start_sb(sb, 3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001030 if (IS_ERR(handle)) {
1031 err = PTR_ERR(handle);
Mingming Cao617ba132006-10-11 01:20:53 -07001032 ext4_warning(sb, __FUNCTION__, "error %d on journal start",err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001033 goto exit_put;
1034 }
1035
1036 lock_super(sb);
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001037 if (o_blocks_count != ext4_blocks_count(es)) {
Mingming Cao617ba132006-10-11 01:20:53 -07001038 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001039 "multiple resizers run on filesystem!");
1040 unlock_super(sb);
1041 err = -EBUSY;
1042 goto exit_put;
1043 }
1044
Mingming Cao617ba132006-10-11 01:20:53 -07001045 if ((err = ext4_journal_get_write_access(handle,
1046 EXT4_SB(sb)->s_sbh))) {
1047 ext4_warning(sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001048 "error %d on journal write access", err);
1049 unlock_super(sb);
Mingming Cao617ba132006-10-11 01:20:53 -07001050 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001051 goto exit_put;
1052 }
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001053 ext4_blocks_count_set(es, o_blocks_count + add);
Mingming Cao617ba132006-10-11 01:20:53 -07001054 ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001055 sb->s_dirt = 1;
1056 unlock_super(sb);
Mingming Cao2ae02102006-10-11 01:21:11 -07001057 ext4_debug("freeing blocks %lu through %llu\n", o_blocks_count,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001058 o_blocks_count + add);
Mingming Cao617ba132006-10-11 01:20:53 -07001059 ext4_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks);
Mingming Cao2ae02102006-10-11 01:21:11 -07001060 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001061 o_blocks_count + add);
Mingming Cao617ba132006-10-11 01:20:53 -07001062 if ((err = ext4_journal_stop(handle)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001063 goto exit_put;
1064 if (test_opt(sb, DEBUG))
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001065 printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
1066 ext4_blocks_count(es));
Mingming Cao617ba132006-10-11 01:20:53 -07001067 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
1068 sizeof(struct ext4_super_block));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001069exit_put:
1070 return err;
Mingming Cao617ba132006-10-11 01:20:53 -07001071} /* ext4_group_extend */