2 * linux/fs/ext4/resize.c
4 * Support for resizing an ext4 filesystem while it is mounted.
6 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com>
8 * This could probably be made into a module, because it is not often in use.
14 #include <linux/errno.h>
15 #include <linux/slab.h>
17 #include "ext4_jbd2.h"
19 #define outside(b, first, last) ((b) < (first) || (b) >= (last))
20 #define inside(b, first, last) ((b) >= (first) && (b) < (last))
22 static int verify_group_input(struct super_block
*sb
,
23 struct ext4_new_group_data
*input
)
25 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
26 struct ext4_super_block
*es
= sbi
->s_es
;
27 ext4_fsblk_t start
= ext4_blocks_count(es
);
28 ext4_fsblk_t end
= start
+ input
->blocks_count
;
29 ext4_group_t group
= input
->group
;
30 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
) +
33 le16_to_cpu(es
->s_reserved_gdt_blocks
)) : 0;
34 ext4_fsblk_t metaend
= start
+ overhead
;
35 struct buffer_head
*bh
= NULL
;
36 ext4_grpblk_t free_blocks_count
, offset
;
39 input
->free_blocks_count
= free_blocks_count
=
40 input
->blocks_count
- 2 - overhead
- sbi
->s_itb_per_group
;
42 if (test_opt(sb
, DEBUG
))
43 printk(KERN_DEBUG
"EXT4-fs: adding %s group %u: %u blocks "
44 "(%d free, %u reserved)\n",
45 ext4_bg_has_super(sb
, input
->group
) ? "normal" :
46 "no-super", input
->group
, input
->blocks_count
,
47 free_blocks_count
, input
->reserved_blocks
);
49 ext4_get_group_no_and_offset(sb
, start
, NULL
, &offset
);
50 if (group
!= sbi
->s_groups_count
)
51 ext4_warning(sb
, "Cannot add at group %u (only %u groups)",
52 input
->group
, sbi
->s_groups_count
);
54 ext4_warning(sb
, "Last group not full");
55 else if (input
->reserved_blocks
> input
->blocks_count
/ 5)
56 ext4_warning(sb
, "Reserved blocks too high (%u)",
57 input
->reserved_blocks
);
58 else if (free_blocks_count
< 0)
59 ext4_warning(sb
, "Bad blocks count %u",
61 else if (!(bh
= sb_bread(sb
, end
- 1)))
62 ext4_warning(sb
, "Cannot read last block (%llu)",
64 else if (outside(input
->block_bitmap
, start
, end
))
65 ext4_warning(sb
, "Block bitmap not in group (block %llu)",
66 (unsigned long long)input
->block_bitmap
);
67 else if (outside(input
->inode_bitmap
, start
, end
))
68 ext4_warning(sb
, "Inode bitmap not in group (block %llu)",
69 (unsigned long long)input
->inode_bitmap
);
70 else if (outside(input
->inode_table
, start
, end
) ||
71 outside(itend
- 1, start
, end
))
72 ext4_warning(sb
, "Inode table not in group (blocks %llu-%llu)",
73 (unsigned long long)input
->inode_table
, itend
- 1);
74 else if (input
->inode_bitmap
== input
->block_bitmap
)
75 ext4_warning(sb
, "Block bitmap same as inode bitmap (%llu)",
76 (unsigned long long)input
->block_bitmap
);
77 else if (inside(input
->block_bitmap
, input
->inode_table
, itend
))
78 ext4_warning(sb
, "Block bitmap (%llu) in inode table "
80 (unsigned long long)input
->block_bitmap
,
81 (unsigned long long)input
->inode_table
, itend
- 1);
82 else if (inside(input
->inode_bitmap
, input
->inode_table
, itend
))
83 ext4_warning(sb
, "Inode bitmap (%llu) in inode table "
85 (unsigned long long)input
->inode_bitmap
,
86 (unsigned long long)input
->inode_table
, itend
- 1);
87 else if (inside(input
->block_bitmap
, start
, metaend
))
88 ext4_warning(sb
, "Block bitmap (%llu) in GDT table (%llu-%llu)",
89 (unsigned long long)input
->block_bitmap
,
91 else if (inside(input
->inode_bitmap
, start
, metaend
))
92 ext4_warning(sb
, "Inode bitmap (%llu) in GDT table (%llu-%llu)",
93 (unsigned long long)input
->inode_bitmap
,
95 else if (inside(input
->inode_table
, start
, metaend
) ||
96 inside(itend
- 1, start
, metaend
))
97 ext4_warning(sb
, "Inode table (%llu-%llu) overlaps GDT table "
99 (unsigned long long)input
->inode_table
,
100 itend
- 1, start
, metaend
- 1);
108 static struct buffer_head
*bclean(handle_t
*handle
, struct super_block
*sb
,
111 struct buffer_head
*bh
;
114 bh
= sb_getblk(sb
, blk
);
116 return ERR_PTR(-EIO
);
117 if ((err
= ext4_journal_get_write_access(handle
, bh
))) {
122 memset(bh
->b_data
, 0, sb
->s_blocksize
);
123 set_buffer_uptodate(bh
);
131 * 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.
135 static int extend_or_restart_transaction(handle_t
*handle
, int thresh
,
136 struct buffer_head
*bh
)
140 if (ext4_handle_has_enough_credits(handle
, thresh
))
143 err
= ext4_journal_extend(handle
, EXT4_MAX_TRANS_DATA
);
147 if ((err
= ext4_journal_restart(handle
, EXT4_MAX_TRANS_DATA
)))
149 if ((err
= ext4_journal_get_write_access(handle
, bh
)))
157 * 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.
163 static int setup_new_group_blocks(struct super_block
*sb
,
164 struct ext4_new_group_data
*input
)
166 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
) ?
169 le16_to_cpu(sbi
->s_es
->s_reserved_gdt_blocks
) : 0;
170 unsigned long gdblocks
= ext4_bg_num_gdb(sb
, input
->group
);
171 struct buffer_head
*bh
;
178 /* This transaction may be extended/restarted along the way */
179 handle
= ext4_journal_start_sb(sb
, EXT4_MAX_TRANS_DATA
);
182 return PTR_ERR(handle
);
184 mutex_lock(&sbi
->s_resize_lock
);
185 if (input
->group
!= sbi
->s_groups_count
) {
190 if (IS_ERR(bh
= bclean(handle
, sb
, input
->block_bitmap
))) {
195 if (ext4_bg_has_super(sb
, input
->group
)) {
196 ext4_debug("mark backup superblock %#04llx (+0)\n", start
);
197 ext4_set_bit(0, bh
->b_data
);
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
;
205 ext4_debug("update backup group %#04llx (+%d)\n", block
, bit
);
207 if ((err
= extend_or_restart_transaction(handle
, 1, bh
)))
210 gdb
= sb_getblk(sb
, block
);
215 if ((err
= ext4_journal_get_write_access(handle
, gdb
))) {
220 memcpy(gdb
->b_data
, sbi
->s_group_desc
[i
]->b_data
, gdb
->b_size
);
221 set_buffer_uptodate(gdb
);
223 ext4_handle_dirty_metadata(handle
, NULL
, gdb
);
224 ext4_set_bit(bit
, bh
->b_data
);
228 /* Zero out all of the reserved backup group descriptor table blocks */
229 ext4_debug("clear inode table blocks %#04llx -> %#04llx\n",
230 block
, sbi
->s_itb_per_group
);
231 err
= sb_issue_zeroout(sb
, gdblocks
+ start
+ 1, reserved_gdb
,
232 GFP_NOFS
, BLKDEV_IFL_WAIT
);
236 ext4_debug("mark block bitmap %#04llx (+%llu)\n", input
->block_bitmap
,
237 input
->block_bitmap
- start
);
238 ext4_set_bit(input
->block_bitmap
- start
, bh
->b_data
);
239 ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input
->inode_bitmap
,
240 input
->inode_bitmap
- start
);
241 ext4_set_bit(input
->inode_bitmap
- start
, bh
->b_data
);
243 /* Zero out all of the inode table blocks */
244 block
= input
->inode_table
;
245 ext4_debug("clear inode table blocks %#04llx -> %#04llx\n",
246 block
, sbi
->s_itb_per_group
);
247 err
= sb_issue_zeroout(sb
, block
, sbi
->s_itb_per_group
,
248 GFP_NOFS
, BLKDEV_IFL_WAIT
);
252 if ((err
= extend_or_restart_transaction(handle
, 2, bh
)))
255 ext4_mark_bitmap_end(input
->blocks_count
, sb
->s_blocksize
* 8,
257 ext4_handle_dirty_metadata(handle
, NULL
, bh
);
259 /* Mark unused entries in inode bitmap used */
260 ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
261 input
->inode_bitmap
, input
->inode_bitmap
- start
);
262 if (IS_ERR(bh
= bclean(handle
, sb
, input
->inode_bitmap
))) {
267 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb
), sb
->s_blocksize
* 8,
269 ext4_handle_dirty_metadata(handle
, NULL
, bh
);
274 mutex_unlock(&sbi
->s_resize_lock
);
275 if ((err2
= ext4_journal_stop(handle
)) && !err
)
282 * Iterate through the groups which hold BACKUP superblock/GDT copies in an
283 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before
284 * calling this for the first time. In a sparse filesystem it will be the
285 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ...
286 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ...
288 static unsigned ext4_list_backups(struct super_block
*sb
, unsigned *three
,
289 unsigned *five
, unsigned *seven
)
291 unsigned *min
= three
;
295 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb
,
296 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER
)) {
318 * Check that all of the backup GDT blocks are held in the primary GDT block.
319 * It is assumed that they are stored in group order. Returns the number of
320 * groups in current filesystem that have BACKUPS, or -ve error code.
322 static int verify_reserved_gdb(struct super_block
*sb
,
323 struct buffer_head
*primary
)
325 const ext4_fsblk_t blk
= primary
->b_blocknr
;
326 const ext4_group_t end
= EXT4_SB(sb
)->s_groups_count
;
331 __le32
*p
= (__le32
*)primary
->b_data
;
334 while ((grp
= ext4_list_backups(sb
, &three
, &five
, &seven
)) < end
) {
335 if (le32_to_cpu(*p
++) !=
336 grp
* EXT4_BLOCKS_PER_GROUP(sb
) + blk
){
337 ext4_warning(sb
, "reserved GDT %llu"
338 " missing grp %d (%llu)",
341 (ext4_fsblk_t
)EXT4_BLOCKS_PER_GROUP(sb
) +
345 if (++gdbackups
> EXT4_ADDR_PER_BLOCK(sb
))
353 * Called when we need to bring a reserved group descriptor table block into
354 * use from the resize inode. The primary copy of the new GDT block currently
355 * is an indirect block (under the double indirect block in the resize inode).
356 * The new backup GDT blocks will be stored as leaf blocks in this indirect
357 * block, in group order. Even though we know all the block numbers we need,
358 * we check to ensure that the resize inode has actually reserved these blocks.
360 * Don't need to update the block bitmaps because the blocks are still in use.
362 * We get all of the error cases out of the way, so that we are sure to not
363 * fail once we start modifying the data on disk, because JBD has no rollback.
365 static int add_new_gdb(handle_t
*handle
, struct inode
*inode
,
366 struct ext4_new_group_data
*input
,
367 struct buffer_head
**primary
)
369 struct super_block
*sb
= inode
->i_sb
;
370 struct ext4_super_block
*es
= EXT4_SB(sb
)->s_es
;
371 unsigned long gdb_num
= input
->group
/ EXT4_DESC_PER_BLOCK(sb
);
372 ext4_fsblk_t gdblock
= EXT4_SB(sb
)->s_sbh
->b_blocknr
+ 1 + gdb_num
;
373 struct buffer_head
**o_group_desc
, **n_group_desc
;
374 struct buffer_head
*dind
;
376 struct ext4_iloc iloc
;
380 if (test_opt(sb
, DEBUG
))
382 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n",
386 * If we are not using the primary superblock/GDT copy don't resize,
387 * because the user tools have no way of handling this. Probably a
388 * bad time to do it anyways.
390 if (EXT4_SB(sb
)->s_sbh
->b_blocknr
!=
391 le32_to_cpu(EXT4_SB(sb
)->s_es
->s_first_data_block
)) {
392 ext4_warning(sb
, "won't resize using backup superblock at %llu",
393 (unsigned long long)EXT4_SB(sb
)->s_sbh
->b_blocknr
);
397 *primary
= sb_bread(sb
, gdblock
);
401 if ((gdbackups
= verify_reserved_gdb(sb
, *primary
)) < 0) {
406 data
= EXT4_I(inode
)->i_data
+ EXT4_DIND_BLOCK
;
407 dind
= sb_bread(sb
, le32_to_cpu(*data
));
413 data
= (__le32
*)dind
->b_data
;
414 if (le32_to_cpu(data
[gdb_num
% EXT4_ADDR_PER_BLOCK(sb
)]) != gdblock
) {
415 ext4_warning(sb
, "new group %u GDT block %llu not reserved",
416 input
->group
, gdblock
);
421 if ((err
= ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
)))
424 if ((err
= ext4_journal_get_write_access(handle
, *primary
)))
427 if ((err
= ext4_journal_get_write_access(handle
, dind
)))
430 /* ext4_reserve_inode_write() gets a reference on the iloc */
431 if ((err
= ext4_reserve_inode_write(handle
, inode
, &iloc
)))
434 n_group_desc
= kmalloc((gdb_num
+ 1) * sizeof(struct buffer_head
*),
439 "not enough memory for %lu groups", gdb_num
+ 1);
444 * Finally, we have all of the possible failures behind us...
446 * Remove new GDT block from inode double-indirect block and clear out
447 * the new GDT block for use (which also "frees" the backup GDT blocks
448 * from the reserved inode). We don't need to change the bitmaps for
449 * these blocks, because they are marked as in-use from being in the
450 * reserved inode, and will become GDT blocks (primary and backup).
452 data
[gdb_num
% EXT4_ADDR_PER_BLOCK(sb
)] = 0;
453 ext4_handle_dirty_metadata(handle
, NULL
, dind
);
455 inode
->i_blocks
-= (gdbackups
+ 1) * sb
->s_blocksize
>> 9;
456 ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
457 memset((*primary
)->b_data
, 0, sb
->s_blocksize
);
458 ext4_handle_dirty_metadata(handle
, NULL
, *primary
);
460 o_group_desc
= EXT4_SB(sb
)->s_group_desc
;
461 memcpy(n_group_desc
, o_group_desc
,
462 EXT4_SB(sb
)->s_gdb_count
* sizeof(struct buffer_head
*));
463 n_group_desc
[gdb_num
] = *primary
;
464 EXT4_SB(sb
)->s_group_desc
= n_group_desc
;
465 EXT4_SB(sb
)->s_gdb_count
++;
468 le16_add_cpu(&es
->s_reserved_gdt_blocks
, -1);
469 ext4_handle_dirty_metadata(handle
, NULL
, EXT4_SB(sb
)->s_sbh
);
474 /* ext4_journal_release_buffer(handle, iloc.bh); */
477 /* ext4_journal_release_buffer(handle, dind); */
479 /* ext4_journal_release_buffer(handle, *primary); */
481 /* ext4_journal_release_buffer(handle, *primary); */
487 ext4_debug("leaving with error %d\n", err
);
492 * Called when we are adding a new group which has a backup copy of each of
493 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks.
494 * We need to add these reserved backup GDT blocks to the resize inode, so
495 * that they are kept for future resizing and not allocated to files.
497 * Each reserved backup GDT block will go into a different indirect block.
498 * The indirect blocks are actually the primary reserved GDT blocks,
499 * so we know in advance what their block numbers are. We only get the
500 * double-indirect block to verify it is pointing to the primary reserved
501 * GDT blocks so we don't overwrite a data block by accident. The reserved
502 * backup GDT blocks are stored in their reserved primary GDT block.
504 static int reserve_backup_gdb(handle_t
*handle
, struct inode
*inode
,
505 struct ext4_new_group_data
*input
)
507 struct super_block
*sb
= inode
->i_sb
;
508 int reserved_gdb
=le16_to_cpu(EXT4_SB(sb
)->s_es
->s_reserved_gdt_blocks
);
509 struct buffer_head
**primary
;
510 struct buffer_head
*dind
;
511 struct ext4_iloc iloc
;
518 primary
= kmalloc(reserved_gdb
* sizeof(*primary
), GFP_NOFS
);
522 data
= EXT4_I(inode
)->i_data
+ EXT4_DIND_BLOCK
;
523 dind
= sb_bread(sb
, le32_to_cpu(*data
));
529 blk
= EXT4_SB(sb
)->s_sbh
->b_blocknr
+ 1 + EXT4_SB(sb
)->s_gdb_count
;
530 data
= (__le32
*)dind
->b_data
+ (EXT4_SB(sb
)->s_gdb_count
%
531 EXT4_ADDR_PER_BLOCK(sb
));
532 end
= (__le32
*)dind
->b_data
+ EXT4_ADDR_PER_BLOCK(sb
);
534 /* Get each reserved primary GDT block and verify it holds backups */
535 for (res
= 0; res
< reserved_gdb
; res
++, blk
++) {
536 if (le32_to_cpu(*data
) != blk
) {
537 ext4_warning(sb
, "reserved block %llu"
538 " not at offset %ld",
540 (long)(data
- (__le32
*)dind
->b_data
));
544 primary
[res
] = sb_bread(sb
, blk
);
549 if ((gdbackups
= verify_reserved_gdb(sb
, primary
[res
])) < 0) {
550 brelse(primary
[res
]);
555 data
= (__le32
*)dind
->b_data
;
558 for (i
= 0; i
< reserved_gdb
; i
++) {
559 if ((err
= ext4_journal_get_write_access(handle
, primary
[i
]))) {
562 for (j = 0; j < i; j++)
563 ext4_journal_release_buffer(handle, primary[j]);
569 if ((err
= ext4_reserve_inode_write(handle
, inode
, &iloc
)))
573 * Finally we can add each of the reserved backup GDT blocks from
574 * the new group to its reserved primary GDT block.
576 blk
= input
->group
* EXT4_BLOCKS_PER_GROUP(sb
);
577 for (i
= 0; i
< reserved_gdb
; i
++) {
579 data
= (__le32
*)primary
[i
]->b_data
;
580 /* printk("reserving backup %lu[%u] = %lu\n",
581 primary[i]->b_blocknr, gdbackups,
582 blk + primary[i]->b_blocknr); */
583 data
[gdbackups
] = cpu_to_le32(blk
+ primary
[i
]->b_blocknr
);
584 err2
= ext4_handle_dirty_metadata(handle
, NULL
, primary
[i
]);
588 inode
->i_blocks
+= reserved_gdb
* sb
->s_blocksize
>> 9;
589 ext4_mark_iloc_dirty(handle
, inode
, &iloc
);
593 brelse(primary
[res
]);
603 * Update the backup copies of the ext4 metadata. These don't need to be part
604 * of the main resize transaction, because e2fsck will re-write them if there
605 * is a problem (basically only OOM will cause a problem). However, we
606 * _should_ update the backups if possible, in case the primary gets trashed
607 * for some reason and we need to run e2fsck from a backup superblock. The
608 * important part is that the new block and inode counts are in the backup
609 * superblocks, and the location of the new group metadata in the GDT backups.
611 * We do not need take the s_resize_lock for this, because these
612 * blocks are not otherwise touched by the filesystem code when it is
613 * mounted. We don't need to worry about last changing from
614 * sbi->s_groups_count, because the worst that can happen is that we
615 * do not copy the full number of backups at this time. The resize
616 * which changed s_groups_count will backup again.
618 static void update_backups(struct super_block
*sb
,
619 int blk_off
, char *data
, int size
)
621 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
622 const ext4_group_t last
= sbi
->s_groups_count
;
623 const int bpg
= EXT4_BLOCKS_PER_GROUP(sb
);
628 int rest
= sb
->s_blocksize
- size
;
632 handle
= ext4_journal_start_sb(sb
, EXT4_MAX_TRANS_DATA
);
633 if (IS_ERR(handle
)) {
635 err
= PTR_ERR(handle
);
639 while ((group
= ext4_list_backups(sb
, &three
, &five
, &seven
)) < last
) {
640 struct buffer_head
*bh
;
642 /* Out of journal space, and can't get more - abort - so sad */
643 if (ext4_handle_valid(handle
) &&
644 handle
->h_buffer_credits
== 0 &&
645 ext4_journal_extend(handle
, EXT4_MAX_TRANS_DATA
) &&
646 (err
= ext4_journal_restart(handle
, EXT4_MAX_TRANS_DATA
)))
649 bh
= sb_getblk(sb
, group
* bpg
+ blk_off
);
654 ext4_debug("update metadata backup %#04lx\n",
655 (unsigned long)bh
->b_blocknr
);
656 if ((err
= ext4_journal_get_write_access(handle
, bh
)))
659 memcpy(bh
->b_data
, data
, size
);
661 memset(bh
->b_data
+ size
, 0, rest
);
662 set_buffer_uptodate(bh
);
664 ext4_handle_dirty_metadata(handle
, NULL
, bh
);
667 if ((err2
= ext4_journal_stop(handle
)) && !err
)
671 * Ugh! Need to have e2fsck write the backup copies. It is too
672 * late to revert the resize, we shouldn't fail just because of
673 * the backup copies (they are only needed in case of corruption).
675 * However, if we got here we have a journal problem too, so we
676 * can't really start a transaction to mark the superblock.
677 * Chicken out and just set the flag on the hope it will be written
678 * to disk, and if not - we will simply wait until next fsck.
682 ext4_warning(sb
, "can't update backup for group %u (err %d), "
683 "forcing fsck on next reboot", group
, err
);
684 sbi
->s_mount_state
&= ~EXT4_VALID_FS
;
685 sbi
->s_es
->s_state
&= cpu_to_le16(~EXT4_VALID_FS
);
686 mark_buffer_dirty(sbi
->s_sbh
);
690 /* Add group descriptor data to an existing or new group descriptor block.
691 * Ensure we handle all possible error conditions _before_ we start modifying
692 * the filesystem, because we cannot abort the transaction and not have it
693 * write the data to disk.
695 * If we are on a GDT block boundary, we need to get the reserved GDT block.
696 * Otherwise, we may need to add backup GDT blocks for a sparse group.
698 * We only need to hold the superblock lock while we are actually adding
699 * in the new group's counts to the superblock. Prior to that we have
700 * not really "added" the group at all. We re-check that we are still
701 * adding in the last group in case things have changed since verifying.
703 int ext4_group_add(struct super_block
*sb
, struct ext4_new_group_data
*input
)
705 struct ext4_sb_info
*sbi
= EXT4_SB(sb
);
706 struct ext4_super_block
*es
= sbi
->s_es
;
707 int reserved_gdb
= ext4_bg_has_super(sb
, input
->group
) ?
708 le16_to_cpu(es
->s_reserved_gdt_blocks
) : 0;
709 struct buffer_head
*primary
= NULL
;
710 struct ext4_group_desc
*gdp
;
711 struct inode
*inode
= NULL
;
713 int gdb_off
, gdb_num
;
716 gdb_num
= input
->group
/ EXT4_DESC_PER_BLOCK(sb
);
717 gdb_off
= input
->group
% EXT4_DESC_PER_BLOCK(sb
);
719 if (gdb_off
== 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb
,
720 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER
)) {
721 ext4_warning(sb
, "Can't resize non-sparse filesystem further");
725 if (ext4_blocks_count(es
) + input
->blocks_count
<
726 ext4_blocks_count(es
)) {
727 ext4_warning(sb
, "blocks_count overflow");
731 if (le32_to_cpu(es
->s_inodes_count
) + EXT4_INODES_PER_GROUP(sb
) <
732 le32_to_cpu(es
->s_inodes_count
)) {
733 ext4_warning(sb
, "inodes_count overflow");
737 if (reserved_gdb
|| gdb_off
== 0) {
738 if (!EXT4_HAS_COMPAT_FEATURE(sb
,
739 EXT4_FEATURE_COMPAT_RESIZE_INODE
)
740 || !le16_to_cpu(es
->s_reserved_gdt_blocks
)) {
742 "No reserved GDT blocks, can't resize");
745 inode
= ext4_iget(sb
, EXT4_RESIZE_INO
);
747 ext4_warning(sb
, "Error opening resize inode");
748 return PTR_ERR(inode
);
753 if ((err
= verify_group_input(sb
, input
)))
756 if ((err
= setup_new_group_blocks(sb
, input
)))
760 * We will always be modifying at least the superblock and a GDT
761 * block. If we are adding a group past the last current GDT block,
762 * we will also modify the inode and the dindirect block. If we
763 * are adding a group with superblock/GDT backups we will also
764 * modify each of the reserved GDT dindirect blocks.
766 handle
= ext4_journal_start_sb(sb
,
767 ext4_bg_has_super(sb
, input
->group
) ?
768 3 + reserved_gdb
: 4);
769 if (IS_ERR(handle
)) {
770 err
= PTR_ERR(handle
);
774 mutex_lock(&sbi
->s_resize_lock
);
775 if (input
->group
!= sbi
->s_groups_count
) {
776 ext4_warning(sb
, "multiple resizers run on filesystem!");
781 if ((err
= ext4_journal_get_write_access(handle
, sbi
->s_sbh
)))
785 * We will only either add reserved group blocks to a backup group
786 * or remove reserved blocks for the first group in a new group block.
787 * Doing both would be mean more complex code, and sane people don't
788 * use non-sparse filesystems anymore. This is already checked above.
791 primary
= sbi
->s_group_desc
[gdb_num
];
792 if ((err
= ext4_journal_get_write_access(handle
, primary
)))
795 if (reserved_gdb
&& ext4_bg_num_gdb(sb
, input
->group
) &&
796 (err
= reserve_backup_gdb(handle
, inode
, input
)))
798 } else if ((err
= add_new_gdb(handle
, inode
, input
, &primary
)))
802 * OK, now we've set up the new group. Time to make it active.
804 * We do not lock all allocations via s_resize_lock
805 * so we have to be safe wrt. concurrent accesses the group
806 * data. So we need to be careful to set all of the relevant
807 * group descriptor data etc. *before* we enable the group.
809 * The key field here is sbi->s_groups_count: as long as
810 * that retains its old value, nobody is going to access the new
813 * So first we update all the descriptor metadata for the new
814 * group; then we update the total disk blocks count; then we
815 * update the groups count to enable the group; then finally we
816 * update the free space counts so that the system can start
817 * using the new disk blocks.
820 /* Update group descriptor block for new group */
821 gdp
= (struct ext4_group_desc
*)((char *)primary
->b_data
+
822 gdb_off
* EXT4_DESC_SIZE(sb
));
824 memset(gdp
, 0, EXT4_DESC_SIZE(sb
));
825 ext4_block_bitmap_set(sb
, gdp
, input
->block_bitmap
); /* LV FIXME */
826 ext4_inode_bitmap_set(sb
, gdp
, input
->inode_bitmap
); /* LV FIXME */
827 ext4_inode_table_set(sb
, gdp
, input
->inode_table
); /* LV FIXME */
828 ext4_free_blks_set(sb
, gdp
, input
->free_blocks_count
);
829 ext4_free_inodes_set(sb
, gdp
, EXT4_INODES_PER_GROUP(sb
));
830 gdp
->bg_flags
= cpu_to_le16(EXT4_BG_INODE_ZEROED
);
831 gdp
->bg_checksum
= ext4_group_desc_csum(sbi
, input
->group
, gdp
);
834 * We can allocate memory for mb_alloc based on the new group
837 err
= ext4_mb_add_groupinfo(sb
, input
->group
, gdp
);
842 * Make the new blocks and inodes valid next. We do this before
843 * increasing the group count so that once the group is enabled,
844 * all of its blocks and inodes are already valid.
846 * We always allocate group-by-group, then block-by-block or
847 * inode-by-inode within a group, so enabling these
848 * blocks/inodes before the group is live won't actually let us
849 * allocate the new space yet.
851 ext4_blocks_count_set(es
, ext4_blocks_count(es
) +
852 input
->blocks_count
);
853 le32_add_cpu(&es
->s_inodes_count
, EXT4_INODES_PER_GROUP(sb
));
856 * We need to protect s_groups_count against other CPUs seeing
857 * inconsistent state in the superblock.
859 * The precise rules we use are:
861 * * Writers of s_groups_count *must* hold s_resize_lock
863 * * Writers must perform a smp_wmb() after updating all dependent
864 * data and before modifying the groups count
866 * * Readers must hold s_resize_lock over the access
868 * * Readers must perform an smp_rmb() after reading the groups count
869 * and before reading any dependent data.
871 * NB. These rules can be relaxed when checking the group count
872 * while freeing data, as we can only allocate from a block
873 * group after serialising against the group count, and we can
874 * only then free after serialising in turn against that
879 /* Update the global fs size fields */
880 sbi
->s_groups_count
++;
882 ext4_handle_dirty_metadata(handle
, NULL
, primary
);
884 /* Update the reserved block counts only once the new group is
886 ext4_r_blocks_count_set(es
, ext4_r_blocks_count(es
) +
887 input
->reserved_blocks
);
889 /* Update the free space counts */
890 percpu_counter_add(&sbi
->s_freeblocks_counter
,
891 input
->free_blocks_count
);
892 percpu_counter_add(&sbi
->s_freeinodes_counter
,
893 EXT4_INODES_PER_GROUP(sb
));
895 if (EXT4_HAS_INCOMPAT_FEATURE(sb
, EXT4_FEATURE_INCOMPAT_FLEX_BG
) &&
896 sbi
->s_log_groups_per_flex
) {
897 ext4_group_t flex_group
;
898 flex_group
= ext4_flex_group(sbi
, input
->group
);
899 atomic_add(input
->free_blocks_count
,
900 &sbi
->s_flex_groups
[flex_group
].free_blocks
);
901 atomic_add(EXT4_INODES_PER_GROUP(sb
),
902 &sbi
->s_flex_groups
[flex_group
].free_inodes
);
905 ext4_handle_dirty_super(handle
, sb
);
908 mutex_unlock(&sbi
->s_resize_lock
);
909 if ((err2
= ext4_journal_stop(handle
)) && !err
)
912 update_backups(sb
, sbi
->s_sbh
->b_blocknr
, (char *)es
,
913 sizeof(struct ext4_super_block
));
914 update_backups(sb
, primary
->b_blocknr
, primary
->b_data
,
920 } /* ext4_group_add */
923 * Extend the filesystem to the new number of blocks specified. This entry
924 * point is only used to extend the current filesystem to the end of the last
925 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>"
926 * for emergencies (because it has no dependencies on reserved blocks).
928 * If we _really_ wanted, we could use default values to call ext4_group_add()
929 * allow the "remount" trick to work for arbitrary resizing, assuming enough
930 * GDT blocks are reserved to grow to the desired size.
932 int ext4_group_extend(struct super_block
*sb
, struct ext4_super_block
*es
,
933 ext4_fsblk_t n_blocks_count
)
935 ext4_fsblk_t o_blocks_count
;
938 struct buffer_head
*bh
;
943 /* We don't need to worry about locking wrt other resizers just
944 * yet: we're going to revalidate es->s_blocks_count after
945 * taking the s_resize_lock below. */
946 o_blocks_count
= ext4_blocks_count(es
);
948 if (test_opt(sb
, DEBUG
))
949 printk(KERN_DEBUG
"EXT4-fs: extending last group from %llu uto %llu blocks\n",
950 o_blocks_count
, n_blocks_count
);
952 if (n_blocks_count
== 0 || n_blocks_count
== o_blocks_count
)
955 if (n_blocks_count
> (sector_t
)(~0ULL) >> (sb
->s_blocksize_bits
- 9)) {
956 printk(KERN_ERR
"EXT4-fs: filesystem on %s:"
957 " too large to resize to %llu blocks safely\n",
958 sb
->s_id
, n_blocks_count
);
959 if (sizeof(sector_t
) < 8)
960 ext4_warning(sb
, "CONFIG_LBDAF not enabled");
964 if (n_blocks_count
< o_blocks_count
) {
965 ext4_warning(sb
, "can't shrink FS - resize aborted");
969 /* Handle the remaining blocks in the last group only. */
970 ext4_get_group_no_and_offset(sb
, o_blocks_count
, &group
, &last
);
973 ext4_warning(sb
, "need to use ext2online to resize further");
977 add
= EXT4_BLOCKS_PER_GROUP(sb
) - last
;
979 if (o_blocks_count
+ add
< o_blocks_count
) {
980 ext4_warning(sb
, "blocks_count overflow");
984 if (o_blocks_count
+ add
> n_blocks_count
)
985 add
= n_blocks_count
- o_blocks_count
;
987 if (o_blocks_count
+ add
< n_blocks_count
)
988 ext4_warning(sb
, "will only finish group (%llu blocks, %u new)",
989 o_blocks_count
+ add
, add
);
991 /* See if the device is actually as big as what was requested */
992 bh
= sb_bread(sb
, o_blocks_count
+ add
- 1);
994 ext4_warning(sb
, "can't read last block, resize aborted");
999 /* We will update the superblock, one block bitmap, and
1000 * one group descriptor via ext4_free_blocks().
1002 handle
= ext4_journal_start_sb(sb
, 3);
1003 if (IS_ERR(handle
)) {
1004 err
= PTR_ERR(handle
);
1005 ext4_warning(sb
, "error %d on journal start", err
);
1009 mutex_lock(&EXT4_SB(sb
)->s_resize_lock
);
1010 if (o_blocks_count
!= ext4_blocks_count(es
)) {
1011 ext4_warning(sb
, "multiple resizers run on filesystem!");
1012 mutex_unlock(&EXT4_SB(sb
)->s_resize_lock
);
1013 ext4_journal_stop(handle
);
1018 if ((err
= ext4_journal_get_write_access(handle
,
1019 EXT4_SB(sb
)->s_sbh
))) {
1020 ext4_warning(sb
, "error %d on journal write access", err
);
1021 mutex_unlock(&EXT4_SB(sb
)->s_resize_lock
);
1022 ext4_journal_stop(handle
);
1025 ext4_blocks_count_set(es
, o_blocks_count
+ add
);
1026 mutex_unlock(&EXT4_SB(sb
)->s_resize_lock
);
1027 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count
,
1028 o_blocks_count
+ add
);
1029 /* We add the blocks to the bitmap and set the group need init bit */
1030 ext4_add_groupblocks(handle
, sb
, o_blocks_count
, add
);
1031 ext4_handle_dirty_super(handle
, sb
);
1032 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count
,
1033 o_blocks_count
+ add
);
1034 if ((err
= ext4_journal_stop(handle
)))
1037 if (test_opt(sb
, DEBUG
))
1038 printk(KERN_DEBUG
"EXT4-fs: extended group to %llu blocks\n",
1039 ext4_blocks_count(es
));
1040 update_backups(sb
, EXT4_SB(sb
)->s_sbh
->b_blocknr
, (char *)es
,
1041 sizeof(struct ext4_super_block
));
1044 } /* ext4_group_extend */