2 * closefs.c --- close an ext2 filesystem
4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
22 static int test_root(int a, int b)
35 int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
37 if (!(fs->super->s_feature_ro_compat &
38 EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
41 if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
42 test_root(group_block, 7))
49 * This function forces out the primary superblock. We need to only
50 * write out those fields which we have changed, since if the
51 * filesystem is mounted, it may have changed some of the other
54 * It takes as input a superblock which has already been byte swapped
58 static errcode_t write_primary_superblock(ext2_filsys fs,
59 struct ext2_super_block *super)
61 __u16 *old_super, *new_super;
62 int check_idx, write_idx, size;
65 if (!fs->io->manager->write_byte || !fs->orig_super) {
66 io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
67 retval = io_channel_write_blk(fs->io, 1, -SUPERBLOCK_SIZE,
69 io_channel_set_blksize(fs->io, fs->blocksize);
73 old_super = (__u16 *) fs->orig_super;
74 new_super = (__u16 *) super;
76 for (check_idx = 0; check_idx < SUPERBLOCK_SIZE/2; check_idx++) {
77 if (old_super[check_idx] == new_super[check_idx])
79 write_idx = check_idx;
80 for (check_idx++; check_idx < SUPERBLOCK_SIZE/2; check_idx++)
81 if (old_super[check_idx] == new_super[check_idx])
83 size = 2 * (check_idx - write_idx);
85 printf("Writing %d bytes starting at %d\n",
88 retval = io_channel_write_byte(fs->io,
89 SUPERBLOCK_OFFSET + (2 * write_idx), size,
90 new_super + write_idx);
99 * Updates the revision to EXT2_DYNAMIC_REV
101 void ext2fs_update_dynamic_rev(ext2_filsys fs)
103 struct ext2_super_block *sb = fs->super;
105 if (sb->s_rev_level > EXT2_GOOD_OLD_REV)
108 sb->s_rev_level = EXT2_DYNAMIC_REV;
109 sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
110 sb->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
111 /* s_uuid is handled by e2fsck already */
112 /* other fields should be left alone */
115 errcode_t ext2fs_flush(ext2_filsys fs)
117 dgrp_t i,j,maxgroup,sgrp;
121 unsigned long fs_state;
122 struct ext2_super_block *super_shadow = 0;
123 struct ext2_group_desc *group_shadow = 0;
124 struct ext2_group_desc *s, *t;
126 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
128 fs_state = fs->super->s_state;
130 fs->super->s_wtime = time(NULL);
131 fs->super->s_block_group_nr = 0;
132 if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
133 retval = EXT2_ET_NO_MEMORY;
134 retval = ext2fs_get_mem(SUPERBLOCK_SIZE,
135 (void **) &super_shadow);
138 retval = ext2fs_get_mem((size_t)(fs->blocksize *
140 (void **) &group_shadow);
143 memset(group_shadow, 0, (size_t) fs->blocksize *
146 /* swap the superblock */
147 *super_shadow = *fs->super;
148 ext2fs_swap_super(super_shadow);
150 /* swap the group descriptors */
151 for (j=0, s=fs->group_desc, t=group_shadow;
152 j < fs->group_desc_count; j++, t++, s++) {
154 ext2fs_swap_group_desc(t);
157 super_shadow = fs->super;
158 group_shadow = fs->group_desc;
162 * Write out master superblock. This has to be done
163 * separately, since it is located at a fixed location
164 * (SUPERBLOCK_OFFSET).
166 retval = write_primary_superblock(fs, super_shadow);
171 * If this is an external journal device, don't write out the
172 * block group descriptors or any of the backup superblocks
174 if (fs->super->s_feature_incompat &
175 EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
181 * Set the state of the FS to be non-valid. (The state has
182 * already been backed up earlier, and will be restored when
185 fs->super->s_state &= ~EXT2_VALID_FS;
186 if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
187 *super_shadow = *fs->super;
188 ext2fs_swap_super(super_shadow);
192 * Write out the master group descriptors, and the backup
193 * superblocks and group descriptors.
195 group_block = fs->super->s_first_data_block;
196 maxgroup = (fs->flags & EXT2_FLAG_MASTER_SB_ONLY) ? 1 :
197 fs->group_desc_count;
198 for (i = 0; i < maxgroup; i++) {
199 if (!ext2fs_bg_has_super(fs, i))
203 if (sgrp > ((1 << 16) - 1))
204 sgrp = (1 << 16) - 1;
205 if (fs->flags & EXT2_FLAG_SWAP_BYTES)
206 super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
208 fs->super->s_block_group_nr = sgrp;
211 retval = io_channel_write_blk(fs->io, group_block,
217 if (fs->flags & EXT2_FLAG_SUPER_ONLY)
219 group_ptr = (char *) group_shadow;
220 for (j=0; j < fs->desc_blocks; j++) {
221 retval = io_channel_write_blk(fs->io,
226 group_ptr += fs->blocksize;
229 group_block += EXT2_BLOCKS_PER_GROUP(fs->super);
231 fs->super->s_block_group_nr = 0;
234 * If the write_bitmaps() function is present, call it to
235 * flush the bitmaps. This is done this way so that a simple
236 * program that doesn't mess with the bitmaps doesn't need to
237 * drag in the bitmaps.c code.
239 if (fs->write_bitmaps) {
240 retval = fs->write_bitmaps(fs);
246 * Flush the blocks out to disk
248 retval = io_channel_flush(fs->io);
250 fs->super->s_state = fs_state;
251 if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
253 ext2fs_free_mem((void **) &super_shadow);
255 ext2fs_free_mem((void **) &group_shadow);
260 errcode_t ext2fs_close(ext2_filsys fs)
264 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
266 if (fs->flags & EXT2_FLAG_DIRTY) {
267 retval = ext2fs_flush(fs);
271 if (fs->write_bitmaps) {
272 retval = fs->write_bitmaps(fs);