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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
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
19#define outside(b, first, last) ((b) < (first) || (b) >= (last))
20#define inside(b, first, last) ((b) >= (first) && (b) < (last))
21
22static int verify_group_input(struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -070023 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070024{
Mingming Cao617ba132006-10-11 01:20:53 -070025 struct ext4_sb_info *sbi = EXT4_SB(sb);
26 struct ext4_super_block *es = sbi->s_es;
Laurent Vivierbd81d8e2006-10-11 01:21:10 -070027 ext4_fsblk_t start = ext4_blocks_count(es);
Mingming Cao617ba132006-10-11 01:20:53 -070028 ext4_fsblk_t end = start + input->blocks_count;
Avantika Mathurfd2d4292008-01-28 23:58:27 -050029 ext4_group_t group = input->group;
Mingming Cao617ba132006-10-11 01:20:53 -070030 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
31 unsigned overhead = ext4_bg_has_super(sb, group) ?
32 (1 + ext4_bg_num_gdb(sb, group) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -070033 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0;
Mingming Cao617ba132006-10-11 01:20:53 -070034 ext4_fsblk_t metaend = start + overhead;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070035 struct buffer_head *bh = NULL;
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070036 ext4_grpblk_t free_blocks_count, offset;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070037 int err = -EINVAL;
38
39 input->free_blocks_count = free_blocks_count =
40 input->blocks_count - 2 - overhead - sbi->s_itb_per_group;
41
42 if (test_opt(sb, DEBUG))
Mingming Cao617ba132006-10-11 01:20:53 -070043 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks "
Dave Kleikampac27a0e2006-10-11 01:20:50 -070044 "(%d free, %u reserved)\n",
Mingming Cao617ba132006-10-11 01:20:53 -070045 ext4_bg_has_super(sb, input->group) ? "normal" :
Dave Kleikampac27a0e2006-10-11 01:20:50 -070046 "no-super", input->group, input->blocks_count,
47 free_blocks_count, input->reserved_blocks);
48
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070049 ext4_get_group_no_and_offset(sb, start, NULL, &offset);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070050 if (group != sbi->s_groups_count)
Eric Sandeen12062dd2010-02-15 14:19:27 -050051 ext4_warning(sb, "Cannot add at group %u (only %u groups)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070052 input->group, sbi->s_groups_count);
Mingming Cao3a5b2ec2006-10-11 01:21:05 -070053 else if (offset != 0)
Eric Sandeen12062dd2010-02-15 14:19:27 -050054 ext4_warning(sb, "Last group not full");
Dave Kleikampac27a0e2006-10-11 01:20:50 -070055 else if (input->reserved_blocks > input->blocks_count / 5)
Eric Sandeen12062dd2010-02-15 14:19:27 -050056 ext4_warning(sb, "Reserved blocks too high (%u)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070057 input->reserved_blocks);
58 else if (free_blocks_count < 0)
Eric Sandeen12062dd2010-02-15 14:19:27 -050059 ext4_warning(sb, "Bad blocks count %u",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070060 input->blocks_count);
61 else if (!(bh = sb_bread(sb, end - 1)))
Eric Sandeen12062dd2010-02-15 14:19:27 -050062 ext4_warning(sb, "Cannot read last block (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -070063 end - 1);
64 else if (outside(input->block_bitmap, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -050065 ext4_warning(sb, "Block bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070066 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070067 else if (outside(input->inode_bitmap, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -050068 ext4_warning(sb, "Inode bitmap not in group (block %llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070069 (unsigned long long)input->inode_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070070 else if (outside(input->inode_table, start, end) ||
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040071 outside(itend - 1, start, end))
Eric Sandeen12062dd2010-02-15 14:19:27 -050072 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070073 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070074 else if (input->inode_bitmap == input->block_bitmap)
Eric Sandeen12062dd2010-02-15 14:19:27 -050075 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070076 (unsigned long long)input->block_bitmap);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070077 else if (inside(input->block_bitmap, input->inode_table, itend))
Eric Sandeen12062dd2010-02-15 14:19:27 -050078 ext4_warning(sb, "Block bitmap (%llu) in inode table "
79 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070080 (unsigned long long)input->block_bitmap,
81 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070082 else if (inside(input->inode_bitmap, input->inode_table, itend))
Eric Sandeen12062dd2010-02-15 14:19:27 -050083 ext4_warning(sb, "Inode bitmap (%llu) in inode table "
84 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070085 (unsigned long long)input->inode_bitmap,
86 (unsigned long long)input->inode_table, itend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070087 else if (inside(input->block_bitmap, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -050088 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070089 (unsigned long long)input->block_bitmap,
90 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070091 else if (inside(input->inode_bitmap, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -050092 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070093 (unsigned long long)input->inode_bitmap,
94 start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095 else if (inside(input->inode_table, start, metaend) ||
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -040096 inside(itend - 1, start, metaend))
Eric Sandeen12062dd2010-02-15 14:19:27 -050097 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table "
98 "(%llu-%llu)",
Randy Dunlap1939e492006-10-28 10:38:26 -070099 (unsigned long long)input->inode_table,
100 itend - 1, start, metaend - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700101 else
102 err = 0;
103 brelse(bh);
104
105 return err;
106}
107
108static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -0700109 ext4_fsblk_t blk)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700110{
111 struct buffer_head *bh;
112 int err;
113
114 bh = sb_getblk(sb, blk);
115 if (!bh)
116 return ERR_PTR(-EIO);
Mingming Cao617ba132006-10-11 01:20:53 -0700117 if ((err = ext4_journal_get_write_access(handle, bh))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118 brelse(bh);
119 bh = ERR_PTR(err);
120 } else {
121 lock_buffer(bh);
122 memset(bh->b_data, 0, sb->s_blocksize);
123 set_buffer_uptodate(bh);
124 unlock_buffer(bh);
125 }
126
127 return bh;
128}
129
130/*
Eric Sandeen14904102007-10-16 18:38:25 -0400131 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA.
132 * If that fails, restart the transaction & regain write access for the
133 * buffer head which is used for block_bitmap modifications.
134 */
135static int extend_or_restart_transaction(handle_t *handle, int thresh,
136 struct buffer_head *bh)
137{
138 int err;
139
Frank Mayhar03901312009-01-07 00:06:22 -0500140 if (ext4_handle_has_enough_credits(handle, thresh))
Eric Sandeen14904102007-10-16 18:38:25 -0400141 return 0;
142
143 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA);
144 if (err < 0)
145 return err;
146 if (err) {
147 if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
148 return err;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400149 if ((err = ext4_journal_get_write_access(handle, bh)))
Eric Sandeen14904102007-10-16 18:38:25 -0400150 return err;
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400151 }
Eric Sandeen14904102007-10-16 18:38:25 -0400152
153 return 0;
154}
155
156/*
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700157 * Set up the block and inode bitmaps, and the inode table for the new group.
158 * This doesn't need to be part of the main transaction, since we are only
159 * changing blocks outside the actual filesystem. We still do journaling to
160 * ensure the recovery is correct in case of a failure just after resize.
161 * If any part of this fails, we simply abort the resize.
162 */
163static int setup_new_group_blocks(struct super_block *sb,
Mingming Cao617ba132006-10-11 01:20:53 -0700164 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700165{
Mingming Cao617ba132006-10-11 01:20:53 -0700166 struct ext4_sb_info *sbi = EXT4_SB(sb);
167 ext4_fsblk_t start = ext4_group_first_block_no(sb, input->group);
168 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700169 le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) : 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700170 unsigned long gdblocks = ext4_bg_num_gdb(sb, input->group);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700171 struct buffer_head *bh;
172 handle_t *handle;
Mingming Cao617ba132006-10-11 01:20:53 -0700173 ext4_fsblk_t block;
174 ext4_grpblk_t bit;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700175 int i;
176 int err = 0, err2;
177
Eric Sandeen14904102007-10-16 18:38:25 -0400178 /* This transaction may be extended/restarted along the way */
179 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
180
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700181 if (IS_ERR(handle))
182 return PTR_ERR(handle);
183
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400184 mutex_lock(&sbi->s_resize_lock);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700185 if (input->group != sbi->s_groups_count) {
186 err = -EBUSY;
187 goto exit_journal;
188 }
189
190 if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
191 err = PTR_ERR(bh);
192 goto exit_journal;
193 }
194
Mingming Cao617ba132006-10-11 01:20:53 -0700195 if (ext4_bg_has_super(sb, input->group)) {
Eric Sandeenc549a952008-01-28 23:58:27 -0500196 ext4_debug("mark backup superblock %#04llx (+0)\n", start);
Mingming Cao617ba132006-10-11 01:20:53 -0700197 ext4_set_bit(0, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700198 }
199
200 /* Copy all of the GDT blocks into the backup in this group */
201 for (i = 0, bit = 1, block = start + 1;
202 i < gdblocks; i++, block++, bit++) {
203 struct buffer_head *gdb;
204
Eric Sandeenc549a952008-01-28 23:58:27 -0500205 ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700206
Eric Sandeen14904102007-10-16 18:38:25 -0400207 if ((err = extend_or_restart_transaction(handle, 1, bh)))
208 goto exit_bh;
209
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700210 gdb = sb_getblk(sb, block);
211 if (!gdb) {
212 err = -EIO;
213 goto exit_bh;
214 }
Mingming Cao617ba132006-10-11 01:20:53 -0700215 if ((err = ext4_journal_get_write_access(handle, gdb))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700216 brelse(gdb);
217 goto exit_bh;
218 }
Eric Sandeen5b615282007-10-16 18:38:25 -0400219 lock_buffer(gdb);
220 memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700221 set_buffer_uptodate(gdb);
Eric Sandeen5b615282007-10-16 18:38:25 -0400222 unlock_buffer(gdb);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500223 err = ext4_handle_dirty_metadata(handle, NULL, gdb);
224 if (unlikely(err)) {
225 brelse(gdb);
226 goto exit_bh;
227 }
Mingming Cao617ba132006-10-11 01:20:53 -0700228 ext4_set_bit(bit, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700229 brelse(gdb);
230 }
231
232 /* Zero out all of the reserved backup group descriptor table blocks */
Lukas Czernera31437b2010-10-27 21:30:05 -0400233 ext4_debug("clear inode table blocks %#04llx -> %#04llx\n",
234 block, sbi->s_itb_per_group);
235 err = sb_issue_zeroout(sb, gdblocks + start + 1, reserved_gdb,
Theodore Ts'oa107e5a2010-10-27 23:44:47 -0400236 GFP_NOFS);
Lukas Czernera31437b2010-10-27 21:30:05 -0400237 if (err)
238 goto exit_bh;
Theodore Ts'o8a7411a2010-12-20 22:30:36 -0500239 for (i = 0, bit = gdblocks + 1; i < reserved_gdb; i++, bit++)
240 ext4_set_bit(bit, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700241
Eric Sandeenc549a952008-01-28 23:58:27 -0500242 ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700243 input->block_bitmap - start);
Mingming Cao617ba132006-10-11 01:20:53 -0700244 ext4_set_bit(input->block_bitmap - start, bh->b_data);
Eric Sandeenc549a952008-01-28 23:58:27 -0500245 ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700246 input->inode_bitmap - start);
Mingming Cao617ba132006-10-11 01:20:53 -0700247 ext4_set_bit(input->inode_bitmap - start, bh->b_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700248
249 /* Zero out all of the inode table blocks */
Lukas Czernera31437b2010-10-27 21:30:05 -0400250 block = input->inode_table;
251 ext4_debug("clear inode table blocks %#04llx -> %#04llx\n",
252 block, sbi->s_itb_per_group);
Theodore Ts'oa107e5a2010-10-27 23:44:47 -0400253 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, GFP_NOFS);
Lukas Czernera31437b2010-10-27 21:30:05 -0400254 if (err)
255 goto exit_bh;
Theodore Ts'o8a7411a2010-12-20 22:30:36 -0500256 for (i = 0, bit = input->inode_table - start;
257 i < sbi->s_itb_per_group; i++, bit++)
258 ext4_set_bit(bit, bh->b_data);
Eric Sandeen14904102007-10-16 18:38:25 -0400259
260 if ((err = extend_or_restart_transaction(handle, 2, bh)))
261 goto exit_bh;
262
Theodore Ts'o61d08672010-10-27 21:30:15 -0400263 ext4_mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8,
264 bh->b_data);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500265 err = ext4_handle_dirty_metadata(handle, NULL, bh);
266 if (unlikely(err)) {
267 ext4_std_error(sb, err);
268 goto exit_bh;
269 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700270 brelse(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700271 /* Mark unused entries in inode bitmap used */
Eric Sandeenc549a952008-01-28 23:58:27 -0500272 ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700273 input->inode_bitmap, input->inode_bitmap - start);
274 if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
275 err = PTR_ERR(bh);
276 goto exit_journal;
277 }
278
Theodore Ts'o61d08672010-10-27 21:30:15 -0400279 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8,
280 bh->b_data);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500281 err = ext4_handle_dirty_metadata(handle, NULL, bh);
282 if (unlikely(err))
283 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700284exit_bh:
285 brelse(bh);
286
287exit_journal:
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400288 mutex_unlock(&sbi->s_resize_lock);
Mingming Cao617ba132006-10-11 01:20:53 -0700289 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700290 err = err2;
291
292 return err;
293}
294
295/*
296 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
Mingming Cao617ba132006-10-11 01:20:53 -0700297 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700298 * calling this for the first time. In a sparse filesystem it will be the
299 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
300 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
301 */
Mingming Cao617ba132006-10-11 01:20:53 -0700302static unsigned ext4_list_backups(struct super_block *sb, unsigned *three,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700303 unsigned *five, unsigned *seven)
304{
305 unsigned *min = three;
306 int mult = 3;
307 unsigned ret;
308
Mingming Cao617ba132006-10-11 01:20:53 -0700309 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
310 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700311 ret = *min;
312 *min += 1;
313 return ret;
314 }
315
316 if (*five < *min) {
317 min = five;
318 mult = 5;
319 }
320 if (*seven < *min) {
321 min = seven;
322 mult = 7;
323 }
324
325 ret = *min;
326 *min *= mult;
327
328 return ret;
329}
330
331/*
332 * Check that all of the backup GDT blocks are held in the primary GDT block.
333 * It is assumed that they are stored in group order. Returns the number of
334 * groups in current filesystem that have BACKUPS, or -ve error code.
335 */
336static int verify_reserved_gdb(struct super_block *sb,
337 struct buffer_head *primary)
338{
Mingming Cao617ba132006-10-11 01:20:53 -0700339 const ext4_fsblk_t blk = primary->b_blocknr;
Avantika Mathurfd2d4292008-01-28 23:58:27 -0500340 const ext4_group_t end = EXT4_SB(sb)->s_groups_count;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700341 unsigned three = 1;
342 unsigned five = 5;
343 unsigned seven = 7;
344 unsigned grp;
345 __le32 *p = (__le32 *)primary->b_data;
346 int gdbackups = 0;
347
Mingming Cao617ba132006-10-11 01:20:53 -0700348 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) {
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700349 if (le32_to_cpu(*p++) !=
350 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){
Eric Sandeen12062dd2010-02-15 14:19:27 -0500351 ext4_warning(sb, "reserved GDT %llu"
Mingming Cao2ae02102006-10-11 01:21:11 -0700352 " missing grp %d (%llu)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700353 blk, grp,
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700354 grp *
355 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
356 blk);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700357 return -EINVAL;
358 }
Mingming Cao617ba132006-10-11 01:20:53 -0700359 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700360 return -EFBIG;
361 }
362
363 return gdbackups;
364}
365
366/*
367 * Called when we need to bring a reserved group descriptor table block into
368 * use from the resize inode. The primary copy of the new GDT block currently
369 * is an indirect block (under the double indirect block in the resize inode).
370 * The new backup GDT blocks will be stored as leaf blocks in this indirect
371 * block, in group order. Even though we know all the block numbers we need,
372 * we check to ensure that the resize inode has actually reserved these blocks.
373 *
374 * Don't need to update the block bitmaps because the blocks are still in use.
375 *
376 * We get all of the error cases out of the way, so that we are sure to not
377 * fail once we start modifying the data on disk, because JBD has no rollback.
378 */
379static int add_new_gdb(handle_t *handle, struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -0700380 struct ext4_new_group_data *input,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700381 struct buffer_head **primary)
382{
383 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700384 struct ext4_super_block *es = EXT4_SB(sb)->s_es;
385 unsigned long gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
386 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700387 struct buffer_head **o_group_desc, **n_group_desc;
388 struct buffer_head *dind;
389 int gdbackups;
Mingming Cao617ba132006-10-11 01:20:53 -0700390 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700391 __le32 *data;
392 int err;
393
394 if (test_opt(sb, DEBUG))
395 printk(KERN_DEBUG
Mingming Cao617ba132006-10-11 01:20:53 -0700396 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 gdb_num);
398
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400399 /*
400 * If we are not using the primary superblock/GDT copy don't resize,
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400401 * because the user tools have no way of handling this. Probably a
402 * bad time to do it anyways.
403 */
Mingming Cao617ba132006-10-11 01:20:53 -0700404 if (EXT4_SB(sb)->s_sbh->b_blocknr !=
405 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500406 ext4_warning(sb, "won't resize using backup superblock at %llu",
Mingming Cao617ba132006-10-11 01:20:53 -0700407 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700408 return -EPERM;
409 }
410
411 *primary = sb_bread(sb, gdblock);
412 if (!*primary)
413 return -EIO;
414
415 if ((gdbackups = verify_reserved_gdb(sb, *primary)) < 0) {
416 err = gdbackups;
417 goto exit_bh;
418 }
419
Mingming Cao617ba132006-10-11 01:20:53 -0700420 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700421 dind = sb_bread(sb, le32_to_cpu(*data));
422 if (!dind) {
423 err = -EIO;
424 goto exit_bh;
425 }
426
427 data = (__le32 *)dind->b_data;
Mingming Cao617ba132006-10-11 01:20:53 -0700428 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500429 ext4_warning(sb, "new group %u GDT block %llu not reserved",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700430 input->group, gdblock);
431 err = -EINVAL;
432 goto exit_dind;
433 }
434
Theodore Ts'ob4097142011-01-10 12:46:59 -0500435 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
436 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700437 goto exit_dind;
438
Theodore Ts'ob4097142011-01-10 12:46:59 -0500439 err = ext4_journal_get_write_access(handle, *primary);
440 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700441 goto exit_sbh;
442
Theodore Ts'ob4097142011-01-10 12:46:59 -0500443 err = ext4_journal_get_write_access(handle, dind);
444 if (unlikely(err))
445 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700446
Mingming Cao617ba132006-10-11 01:20:53 -0700447 /* ext4_reserve_inode_write() gets a reference on the iloc */
Theodore Ts'ob4097142011-01-10 12:46:59 -0500448 err = ext4_reserve_inode_write(handle, inode, &iloc);
449 if (unlikely(err))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 goto exit_dindj;
451
452 n_group_desc = kmalloc((gdb_num + 1) * sizeof(struct buffer_head *),
Josef Bacik216553c2008-04-29 22:02:02 -0400453 GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700454 if (!n_group_desc) {
455 err = -ENOMEM;
Eric Sandeen12062dd2010-02-15 14:19:27 -0500456 ext4_warning(sb,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700457 "not enough memory for %lu groups", gdb_num + 1);
458 goto exit_inode;
459 }
460
461 /*
462 * Finally, we have all of the possible failures behind us...
463 *
464 * Remove new GDT block from inode double-indirect block and clear out
465 * the new GDT block for use (which also "frees" the backup GDT blocks
466 * from the reserved inode). We don't need to change the bitmaps for
467 * these blocks, because they are marked as in-use from being in the
468 * reserved inode, and will become GDT blocks (primary and backup).
469 */
Mingming Cao617ba132006-10-11 01:20:53 -0700470 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0;
Theodore Ts'ob4097142011-01-10 12:46:59 -0500471 err = ext4_handle_dirty_metadata(handle, NULL, dind);
472 if (unlikely(err)) {
473 ext4_std_error(sb, err);
474 goto exit_inode;
475 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700476 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700477 ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700478 memset((*primary)->b_data, 0, sb->s_blocksize);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500479 err = ext4_handle_dirty_metadata(handle, NULL, *primary);
480 if (unlikely(err)) {
481 ext4_std_error(sb, err);
482 goto exit_inode;
483 }
484 brelse(dind);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700485
Mingming Cao617ba132006-10-11 01:20:53 -0700486 o_group_desc = EXT4_SB(sb)->s_group_desc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700487 memcpy(n_group_desc, o_group_desc,
Mingming Cao617ba132006-10-11 01:20:53 -0700488 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700489 n_group_desc[gdb_num] = *primary;
Mingming Cao617ba132006-10-11 01:20:53 -0700490 EXT4_SB(sb)->s_group_desc = n_group_desc;
491 EXT4_SB(sb)->s_gdb_count++;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700492 kfree(o_group_desc);
493
Marcin Slusarze8546d02008-04-17 10:38:59 -0400494 le16_add_cpu(&es->s_reserved_gdt_blocks, -1);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500495 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
496 if (err)
497 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700498
Theodore Ts'ob4097142011-01-10 12:46:59 -0500499 return err;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700500
501exit_inode:
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400502 /* ext4_journal_release_buffer(handle, iloc.bh); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700503 brelse(iloc.bh);
504exit_dindj:
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400505 /* ext4_journal_release_buffer(handle, dind); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700506exit_sbh:
Theodore Ts'ob4097142011-01-10 12:46:59 -0500507 /* ext4_journal_release_buffer(handle, EXT4_SB(sb)->s_sbh); */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700508exit_dind:
509 brelse(dind);
510exit_bh:
511 brelse(*primary);
512
Mingming Cao617ba132006-10-11 01:20:53 -0700513 ext4_debug("leaving with error %d\n", err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700514 return err;
515}
516
517/*
518 * Called when we are adding a new group which has a backup copy of each of
519 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
520 * We need to add these reserved backup GDT blocks to the resize inode, so
521 * that they are kept for future resizing and not allocated to files.
522 *
523 * Each reserved backup GDT block will go into a different indirect block.
524 * The indirect blocks are actually the primary reserved GDT blocks,
525 * so we know in advance what their block numbers are. We only get the
526 * double-indirect block to verify it is pointing to the primary reserved
527 * GDT blocks so we don't overwrite a data block by accident. The reserved
528 * backup GDT blocks are stored in their reserved primary GDT block.
529 */
530static int reserve_backup_gdb(handle_t *handle, struct inode *inode,
Mingming Cao617ba132006-10-11 01:20:53 -0700531 struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700532{
533 struct super_block *sb = inode->i_sb;
Mingming Cao617ba132006-10-11 01:20:53 -0700534 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700535 struct buffer_head **primary;
536 struct buffer_head *dind;
Mingming Cao617ba132006-10-11 01:20:53 -0700537 struct ext4_iloc iloc;
538 ext4_fsblk_t blk;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700539 __le32 *data, *end;
540 int gdbackups = 0;
541 int res, i;
542 int err;
543
Josef Bacik216553c2008-04-29 22:02:02 -0400544 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700545 if (!primary)
546 return -ENOMEM;
547
Mingming Cao617ba132006-10-11 01:20:53 -0700548 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700549 dind = sb_bread(sb, le32_to_cpu(*data));
550 if (!dind) {
551 err = -EIO;
552 goto exit_free;
553 }
554
Mingming Cao617ba132006-10-11 01:20:53 -0700555 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count;
Josef Bacik94460092008-06-06 18:05:52 -0400556 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count %
557 EXT4_ADDR_PER_BLOCK(sb));
Mingming Cao617ba132006-10-11 01:20:53 -0700558 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700559
560 /* Get each reserved primary GDT block and verify it holds backups */
561 for (res = 0; res < reserved_gdb; res++, blk++) {
562 if (le32_to_cpu(*data) != blk) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500563 ext4_warning(sb, "reserved block %llu"
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700564 " not at offset %ld",
565 blk,
566 (long)(data - (__le32 *)dind->b_data));
567 err = -EINVAL;
568 goto exit_bh;
569 }
570 primary[res] = sb_bread(sb, blk);
571 if (!primary[res]) {
572 err = -EIO;
573 goto exit_bh;
574 }
575 if ((gdbackups = verify_reserved_gdb(sb, primary[res])) < 0) {
576 brelse(primary[res]);
577 err = gdbackups;
578 goto exit_bh;
579 }
580 if (++data >= end)
581 data = (__le32 *)dind->b_data;
582 }
583
584 for (i = 0; i < reserved_gdb; i++) {
Mingming Cao617ba132006-10-11 01:20:53 -0700585 if ((err = ext4_journal_get_write_access(handle, primary[i]))) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700586 /*
587 int j;
588 for (j = 0; j < i; j++)
Mingming Cao617ba132006-10-11 01:20:53 -0700589 ext4_journal_release_buffer(handle, primary[j]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700590 */
591 goto exit_bh;
592 }
593 }
594
Mingming Cao617ba132006-10-11 01:20:53 -0700595 if ((err = ext4_reserve_inode_write(handle, inode, &iloc)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700596 goto exit_bh;
597
598 /*
599 * Finally we can add each of the reserved backup GDT blocks from
600 * the new group to its reserved primary GDT block.
601 */
Mingming Cao617ba132006-10-11 01:20:53 -0700602 blk = input->group * EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700603 for (i = 0; i < reserved_gdb; i++) {
604 int err2;
605 data = (__le32 *)primary[i]->b_data;
606 /* printk("reserving backup %lu[%u] = %lu\n",
607 primary[i]->b_blocknr, gdbackups,
608 blk + primary[i]->b_blocknr); */
609 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr);
Frank Mayhar03901312009-01-07 00:06:22 -0500610 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700611 if (!err)
612 err = err2;
613 }
614 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9;
Mingming Cao617ba132006-10-11 01:20:53 -0700615 ext4_mark_iloc_dirty(handle, inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700616
617exit_bh:
618 while (--res >= 0)
619 brelse(primary[res]);
620 brelse(dind);
621
622exit_free:
623 kfree(primary);
624
625 return err;
626}
627
628/*
Mingming Cao617ba132006-10-11 01:20:53 -0700629 * Update the backup copies of the ext4 metadata. These don't need to be part
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700630 * of the main resize transaction, because e2fsck will re-write them if there
631 * is a problem (basically only OOM will cause a problem). However, we
632 * _should_ update the backups if possible, in case the primary gets trashed
633 * for some reason and we need to run e2fsck from a backup superblock. The
634 * important part is that the new block and inode counts are in the backup
635 * superblocks, and the location of the new group metadata in the GDT backups.
636 *
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400637 * We do not need take the s_resize_lock for this, because these
638 * blocks are not otherwise touched by the filesystem code when it is
639 * mounted. We don't need to worry about last changing from
640 * sbi->s_groups_count, because the worst that can happen is that we
641 * do not copy the full number of backups at this time. The resize
642 * which changed s_groups_count will backup again.
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700643 */
644static void update_backups(struct super_block *sb,
645 int blk_off, char *data, int size)
646{
Mingming Cao617ba132006-10-11 01:20:53 -0700647 struct ext4_sb_info *sbi = EXT4_SB(sb);
Avantika Mathurfd2d4292008-01-28 23:58:27 -0500648 const ext4_group_t last = sbi->s_groups_count;
Mingming Cao617ba132006-10-11 01:20:53 -0700649 const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700650 unsigned three = 1;
651 unsigned five = 5;
652 unsigned seven = 7;
Avantika Mathurfd2d4292008-01-28 23:58:27 -0500653 ext4_group_t group;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700654 int rest = sb->s_blocksize - size;
655 handle_t *handle;
656 int err = 0, err2;
657
Mingming Cao617ba132006-10-11 01:20:53 -0700658 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700659 if (IS_ERR(handle)) {
660 group = 1;
661 err = PTR_ERR(handle);
662 goto exit_err;
663 }
664
Mingming Cao617ba132006-10-11 01:20:53 -0700665 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700666 struct buffer_head *bh;
667
668 /* Out of journal space, and can't get more - abort - so sad */
Frank Mayhar03901312009-01-07 00:06:22 -0500669 if (ext4_handle_valid(handle) &&
670 handle->h_buffer_credits == 0 &&
Mingming Cao617ba132006-10-11 01:20:53 -0700671 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) &&
672 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700673 break;
674
675 bh = sb_getblk(sb, group * bpg + blk_off);
676 if (!bh) {
677 err = -EIO;
678 break;
679 }
Mingming Cao617ba132006-10-11 01:20:53 -0700680 ext4_debug("update metadata backup %#04lx\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700681 (unsigned long)bh->b_blocknr);
Mingming Cao617ba132006-10-11 01:20:53 -0700682 if ((err = ext4_journal_get_write_access(handle, bh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700683 break;
684 lock_buffer(bh);
685 memcpy(bh->b_data, data, size);
686 if (rest)
687 memset(bh->b_data + size, 0, rest);
688 set_buffer_uptodate(bh);
689 unlock_buffer(bh);
Theodore Ts'ob4097142011-01-10 12:46:59 -0500690 err = ext4_handle_dirty_metadata(handle, NULL, bh);
691 if (unlikely(err))
692 ext4_std_error(sb, err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700693 brelse(bh);
694 }
Mingming Cao617ba132006-10-11 01:20:53 -0700695 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700696 err = err2;
697
698 /*
699 * Ugh! Need to have e2fsck write the backup copies. It is too
700 * late to revert the resize, we shouldn't fail just because of
701 * the backup copies (they are only needed in case of corruption).
702 *
703 * However, if we got here we have a journal problem too, so we
704 * can't really start a transaction to mark the superblock.
705 * Chicken out and just set the flag on the hope it will be written
706 * to disk, and if not - we will simply wait until next fsck.
707 */
708exit_err:
709 if (err) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500710 ext4_warning(sb, "can't update backup for group %u (err %d), "
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700711 "forcing fsck on next reboot", group, err);
Mingming Cao617ba132006-10-11 01:20:53 -0700712 sbi->s_mount_state &= ~EXT4_VALID_FS;
713 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700714 mark_buffer_dirty(sbi->s_sbh);
715 }
716}
717
718/* Add group descriptor data to an existing or new group descriptor block.
719 * Ensure we handle all possible error conditions _before_ we start modifying
720 * the filesystem, because we cannot abort the transaction and not have it
721 * write the data to disk.
722 *
723 * If we are on a GDT block boundary, we need to get the reserved GDT block.
724 * Otherwise, we may need to add backup GDT blocks for a sparse group.
725 *
726 * We only need to hold the superblock lock while we are actually adding
727 * in the new group's counts to the superblock. Prior to that we have
728 * not really "added" the group at all. We re-check that we are still
729 * adding in the last group in case things have changed since verifying.
730 */
Mingming Cao617ba132006-10-11 01:20:53 -0700731int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700732{
Mingming Cao617ba132006-10-11 01:20:53 -0700733 struct ext4_sb_info *sbi = EXT4_SB(sb);
734 struct ext4_super_block *es = sbi->s_es;
735 int reserved_gdb = ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700736 le16_to_cpu(es->s_reserved_gdt_blocks) : 0;
737 struct buffer_head *primary = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700738 struct ext4_group_desc *gdp;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700739 struct inode *inode = NULL;
740 handle_t *handle;
741 int gdb_off, gdb_num;
742 int err, err2;
743
Mingming Cao617ba132006-10-11 01:20:53 -0700744 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb);
745 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700746
Mingming Cao617ba132006-10-11 01:20:53 -0700747 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb,
748 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500749 ext4_warning(sb, "Can't resize non-sparse filesystem further");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700750 return -EPERM;
751 }
752
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700753 if (ext4_blocks_count(es) + input->blocks_count <
754 ext4_blocks_count(es)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500755 ext4_warning(sb, "blocks_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700756 return -EINVAL;
757 }
758
Mingming Cao617ba132006-10-11 01:20:53 -0700759 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) <
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700760 le32_to_cpu(es->s_inodes_count)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500761 ext4_warning(sb, "inodes_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700762 return -EINVAL;
763 }
764
765 if (reserved_gdb || gdb_off == 0) {
Mingming Cao617ba132006-10-11 01:20:53 -0700766 if (!EXT4_HAS_COMPAT_FEATURE(sb,
Josef Bacik37609fd2008-08-19 22:13:41 -0400767 EXT4_FEATURE_COMPAT_RESIZE_INODE)
768 || !le16_to_cpu(es->s_reserved_gdt_blocks)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500769 ext4_warning(sb,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700770 "No reserved GDT blocks, can't resize");
771 return -EPERM;
772 }
David Howells1d1fe1e2008-02-07 00:15:37 -0800773 inode = ext4_iget(sb, EXT4_RESIZE_INO);
774 if (IS_ERR(inode)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500775 ext4_warning(sb, "Error opening resize inode");
David Howells1d1fe1e2008-02-07 00:15:37 -0800776 return PTR_ERR(inode);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700777 }
778 }
779
Aneesh Kumar K.V920313a2009-01-05 21:36:19 -0500780
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700781 if ((err = verify_group_input(sb, input)))
782 goto exit_put;
783
784 if ((err = setup_new_group_blocks(sb, input)))
785 goto exit_put;
786
787 /*
788 * We will always be modifying at least the superblock and a GDT
789 * block. If we are adding a group past the last current GDT block,
790 * we will also modify the inode and the dindirect block. If we
791 * are adding a group with superblock/GDT backups we will also
792 * modify each of the reserved GDT dindirect blocks.
793 */
Mingming Cao617ba132006-10-11 01:20:53 -0700794 handle = ext4_journal_start_sb(sb,
795 ext4_bg_has_super(sb, input->group) ?
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700796 3 + reserved_gdb : 4);
797 if (IS_ERR(handle)) {
798 err = PTR_ERR(handle);
799 goto exit_put;
800 }
801
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400802 mutex_lock(&sbi->s_resize_lock);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700803 if (input->group != sbi->s_groups_count) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500804 ext4_warning(sb, "multiple resizers run on filesystem!");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700805 err = -EBUSY;
806 goto exit_journal;
807 }
808
Mingming Cao617ba132006-10-11 01:20:53 -0700809 if ((err = ext4_journal_get_write_access(handle, sbi->s_sbh)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700810 goto exit_journal;
811
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400812 /*
813 * We will only either add reserved group blocks to a backup group
814 * or remove reserved blocks for the first group in a new group block.
815 * Doing both would be mean more complex code, and sane people don't
816 * use non-sparse filesystems anymore. This is already checked above.
817 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700818 if (gdb_off) {
819 primary = sbi->s_group_desc[gdb_num];
Mingming Cao617ba132006-10-11 01:20:53 -0700820 if ((err = ext4_journal_get_write_access(handle, primary)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700821 goto exit_journal;
822
Mingming Cao617ba132006-10-11 01:20:53 -0700823 if (reserved_gdb && ext4_bg_num_gdb(sb, input->group) &&
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700824 (err = reserve_backup_gdb(handle, inode, input)))
825 goto exit_journal;
826 } else if ((err = add_new_gdb(handle, inode, input, &primary)))
827 goto exit_journal;
828
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400829 /*
830 * OK, now we've set up the new group. Time to make it active.
831 *
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400832 * We do not lock all allocations via s_resize_lock
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400833 * so we have to be safe wrt. concurrent accesses the group
834 * data. So we need to be careful to set all of the relevant
835 * group descriptor data etc. *before* we enable the group.
836 *
837 * The key field here is sbi->s_groups_count: as long as
838 * that retains its old value, nobody is going to access the new
839 * group.
840 *
841 * So first we update all the descriptor metadata for the new
842 * group; then we update the total disk blocks count; then we
843 * update the groups count to enable the group; then finally we
844 * update the free space counts so that the system can start
845 * using the new disk blocks.
846 */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700847
848 /* Update group descriptor block for new group */
Frederic Bohe28569222008-06-20 11:48:48 -0400849 gdp = (struct ext4_group_desc *)((char *)primary->b_data +
850 gdb_off * EXT4_DESC_SIZE(sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700851
Theodore Ts'ofdff73f2009-01-26 19:06:41 -0500852 memset(gdp, 0, EXT4_DESC_SIZE(sb));
Alexandre Ratchov8fadc142006-10-11 01:21:15 -0700853 ext4_block_bitmap_set(sb, gdp, input->block_bitmap); /* LV FIXME */
854 ext4_inode_bitmap_set(sb, gdp, input->inode_bitmap); /* LV FIXME */
855 ext4_inode_table_set(sb, gdp, input->inode_table); /* LV FIXME */
Aneesh Kumar K.V560671a2009-01-05 22:20:24 -0500856 ext4_free_blks_set(sb, gdp, input->free_blocks_count);
857 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb));
Theodore Ts'ofdff73f2009-01-26 19:06:41 -0500858 gdp->bg_flags = cpu_to_le16(EXT4_BG_INODE_ZEROED);
Andreas Dilger717d50e2007-10-16 18:38:25 -0400859 gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700860
861 /*
Frederic Bohe5f21b0e2008-07-11 19:27:31 -0400862 * We can allocate memory for mb_alloc based on the new group
863 * descriptor
864 */
Aneesh Kumar K.V920313a2009-01-05 21:36:19 -0500865 err = ext4_mb_add_groupinfo(sb, input->group, gdp);
Aneesh Kumar K.V08c3a812009-09-09 23:50:17 -0400866 if (err)
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -0400867 goto exit_journal;
868
Frederic Bohe5f21b0e2008-07-11 19:27:31 -0400869 /*
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700870 * 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);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400881 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700882
883 /*
884 * We need to protect s_groups_count against other CPUs seeing
885 * inconsistent state in the superblock.
886 *
887 * The precise rules we use are:
888 *
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400889 * * Writers of s_groups_count *must* hold s_resize_lock
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700890 * AND
891 * * Writers must perform a smp_wmb() after updating all dependent
892 * data and before modifying the groups count
893 *
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400894 * * Readers must hold s_resize_lock over the access
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700895 * OR
896 * * Readers must perform an smp_rmb() after reading the groups count
897 * and before reading any dependent data.
898 *
899 * NB. These rules can be relaxed when checking the group count
900 * while freeing data, as we can only allocate from a block
901 * group after serialising against the group count, and we can
902 * only then free after serialising in turn against that
903 * allocation.
904 */
905 smp_wmb();
906
907 /* Update the global fs size fields */
908 sbi->s_groups_count++;
909
Theodore Ts'ob4097142011-01-10 12:46:59 -0500910 err = ext4_handle_dirty_metadata(handle, NULL, primary);
911 if (unlikely(err)) {
912 ext4_std_error(sb, err);
913 goto exit_journal;
914 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700915
916 /* Update the reserved block counts only once the new group is
917 * active. */
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700918 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) +
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700919 input->reserved_blocks);
920
921 /* Update the free space counts */
Peter Zijlstraaa0dff22007-10-16 23:25:42 -0700922 percpu_counter_add(&sbi->s_freeblocks_counter,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700923 input->free_blocks_count);
Peter Zijlstraaa0dff22007-10-16 23:25:42 -0700924 percpu_counter_add(&sbi->s_freeinodes_counter,
Mingming Cao617ba132006-10-11 01:20:53 -0700925 EXT4_INODES_PER_GROUP(sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700926
Eric Sandeen42007ef2010-05-16 01:00:00 -0400927 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
928 sbi->s_log_groups_per_flex) {
Frederic Bohec62a11f2008-09-08 10:20:24 -0400929 ext4_group_t flex_group;
930 flex_group = ext4_flex_group(sbi, input->group);
Theodore Ts'o9f24e422009-03-04 19:09:10 -0500931 atomic_add(input->free_blocks_count,
932 &sbi->s_flex_groups[flex_group].free_blocks);
933 atomic_add(EXT4_INODES_PER_GROUP(sb),
934 &sbi->s_flex_groups[flex_group].free_inodes);
Frederic Bohec62a11f2008-09-08 10:20:24 -0400935 }
936
Theodore Ts'oa0375152010-06-11 23:14:04 -0400937 ext4_handle_dirty_super(handle, sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700938
939exit_journal:
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400940 mutex_unlock(&sbi->s_resize_lock);
Mingming Cao617ba132006-10-11 01:20:53 -0700941 if ((err2 = ext4_journal_stop(handle)) && !err)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700942 err = err2;
943 if (!err) {
944 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
Mingming Cao617ba132006-10-11 01:20:53 -0700945 sizeof(struct ext4_super_block));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700946 update_backups(sb, primary->b_blocknr, primary->b_data,
947 primary->b_size);
948 }
949exit_put:
950 iput(inode);
951 return err;
Mingming Cao617ba132006-10-11 01:20:53 -0700952} /* ext4_group_add */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700953
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -0400954/*
955 * Extend the filesystem to the new number of blocks specified. This entry
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700956 * point is only used to extend the current filesystem to the end of the last
957 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
958 * for emergencies (because it has no dependencies on reserved blocks).
959 *
Mingming Cao617ba132006-10-11 01:20:53 -0700960 * If we _really_ wanted, we could use default values to call ext4_group_add()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700961 * allow the "remount" trick to work for arbitrary resizing, assuming enough
962 * GDT blocks are reserved to grow to the desired size.
963 */
Mingming Cao617ba132006-10-11 01:20:53 -0700964int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
965 ext4_fsblk_t n_blocks_count)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700966{
Mingming Cao617ba132006-10-11 01:20:53 -0700967 ext4_fsblk_t o_blocks_count;
Mingming Cao617ba132006-10-11 01:20:53 -0700968 ext4_grpblk_t last;
969 ext4_grpblk_t add;
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400970 struct buffer_head *bh;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700971 handle_t *handle;
972 int err;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -0400973 ext4_group_t group;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700974
975 /* We don't need to worry about locking wrt other resizers just
976 * yet: we're going to revalidate es->s_blocks_count after
Theodore Ts'o32ed5052009-04-25 22:53:39 -0400977 * taking the s_resize_lock below. */
Laurent Vivierbd81d8e2006-10-11 01:21:10 -0700978 o_blocks_count = ext4_blocks_count(es);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700979
980 if (test_opt(sb, DEBUG))
Mingming Cao2ae02102006-10-11 01:21:11 -0700981 printk(KERN_DEBUG "EXT4-fs: extending last group from %llu uto %llu blocks\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700982 o_blocks_count, n_blocks_count);
983
984 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count)
985 return 0;
986
987 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700988 printk(KERN_ERR "EXT4-fs: filesystem on %s:"
Mingming Cao2ae02102006-10-11 01:21:11 -0700989 " too large to resize to %llu blocks safely\n",
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700990 sb->s_id, n_blocks_count);
991 if (sizeof(sector_t) < 8)
Eric Sandeen12062dd2010-02-15 14:19:27 -0500992 ext4_warning(sb, "CONFIG_LBDAF not enabled");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700993 return -EINVAL;
994 }
995
996 if (n_blocks_count < o_blocks_count) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500997 ext4_warning(sb, "can't shrink FS - resize aborted");
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700998 return -EBUSY;
999 }
1000
1001 /* Handle the remaining blocks in the last group only. */
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04001002 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001003
1004 if (last == 0) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001005 ext4_warning(sb, "need to use ext2online to resize further");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001006 return -EPERM;
1007 }
1008
Mingming Cao617ba132006-10-11 01:20:53 -07001009 add = EXT4_BLOCKS_PER_GROUP(sb) - last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001010
1011 if (o_blocks_count + add < o_blocks_count) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001012 ext4_warning(sb, "blocks_count overflow");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001013 return -EINVAL;
1014 }
1015
1016 if (o_blocks_count + add > n_blocks_count)
1017 add = n_blocks_count - o_blocks_count;
1018
1019 if (o_blocks_count + add < n_blocks_count)
Eric Sandeen12062dd2010-02-15 14:19:27 -05001020 ext4_warning(sb, "will only finish group (%llu blocks, %u new)",
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001021 o_blocks_count + add, add);
1022
1023 /* See if the device is actually as big as what was requested */
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001024 bh = sb_bread(sb, o_blocks_count + add - 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001025 if (!bh) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001026 ext4_warning(sb, "can't read last block, resize aborted");
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001027 return -ENOSPC;
1028 }
1029 brelse(bh);
1030
1031 /* We will update the superblock, one block bitmap, and
Mingming Cao617ba132006-10-11 01:20:53 -07001032 * one group descriptor via ext4_free_blocks().
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001033 */
Mingming Cao617ba132006-10-11 01:20:53 -07001034 handle = ext4_journal_start_sb(sb, 3);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001035 if (IS_ERR(handle)) {
1036 err = PTR_ERR(handle);
Eric Sandeen12062dd2010-02-15 14:19:27 -05001037 ext4_warning(sb, "error %d on journal start", err);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001038 goto exit_put;
1039 }
1040
Theodore Ts'o32ed5052009-04-25 22:53:39 -04001041 mutex_lock(&EXT4_SB(sb)->s_resize_lock);
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001042 if (o_blocks_count != ext4_blocks_count(es)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001043 ext4_warning(sb, "multiple resizers run on filesystem!");
Theodore Ts'o32ed5052009-04-25 22:53:39 -04001044 mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
Akinobu Mita5606bf52008-02-25 15:37:42 -05001045 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001046 err = -EBUSY;
1047 goto exit_put;
1048 }
1049
Mingming Cao617ba132006-10-11 01:20:53 -07001050 if ((err = ext4_journal_get_write_access(handle,
1051 EXT4_SB(sb)->s_sbh))) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001052 ext4_warning(sb, "error %d on journal write access", err);
Theodore Ts'o32ed5052009-04-25 22:53:39 -04001053 mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
Mingming Cao617ba132006-10-11 01:20:53 -07001054 ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001055 goto exit_put;
1056 }
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001057 ext4_blocks_count_set(es, o_blocks_count + add);
Theodore Ts'o32ed5052009-04-25 22:53:39 -04001058 mutex_unlock(&EXT4_SB(sb)->s_resize_lock);
Eric Sandeenc549a952008-01-28 23:58:27 -05001059 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001060 o_blocks_count + add);
Aneesh Kumar K.Ve21675d2009-01-05 21:36:02 -05001061 /* We add the blocks to the bitmap and set the group need init bit */
1062 ext4_add_groupblocks(handle, sb, o_blocks_count, add);
Theodore Ts'oa0375152010-06-11 23:14:04 -04001063 ext4_handle_dirty_super(handle, sb);
Mingming Cao2ae02102006-10-11 01:21:11 -07001064 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001065 o_blocks_count + add);
Mingming Cao617ba132006-10-11 01:20:53 -07001066 if ((err = ext4_journal_stop(handle)))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001067 goto exit_put;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04001068
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001069 if (test_opt(sb, DEBUG))
Laurent Vivierbd81d8e2006-10-11 01:21:10 -07001070 printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
1071 ext4_blocks_count(es));
Mingming Cao617ba132006-10-11 01:20:53 -07001072 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es,
1073 sizeof(struct ext4_super_block));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001074exit_put:
1075 return err;
Mingming Cao617ba132006-10-11 01:20:53 -07001076} /* ext4_group_extend */