42 static void ext2_write_super(struct super_block *sb);
43 static int ext2_remount (struct super_block * sb, int * flags, char * data);
45 static int ext2_sync_fs(struct super_block *sb, int wait);
46 static int ext2_freeze(struct super_block *sb);
47 static int ext2_unfreeze(struct super_block *sb);
49 void ext2_error(struct super_block *sb, const char *function,  in ext2_error()  argument
54 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_error()
57 	if (!sb_rdonly(sb)) {  in ext2_error()
62 		ext2_sync_super(sb, es, 1);  in ext2_error()
71 	       sb->s_id, function, &vaf);  in ext2_error()
75 	if (test_opt(sb, ERRORS_PANIC))  in ext2_error()
77 	if (!sb_rdonly(sb) && test_opt(sb, ERRORS_RO)) {  in ext2_error()
78 		ext2_msg(sb, KERN_CRIT,  in ext2_error()
80 		sb->s_flags |= SB_RDONLY;  in ext2_error()
84 void ext2_msg(struct super_block *sb, const char *prefix,  in ext2_msg()  argument
95 	printk("%sEXT2-fs (%s): %pV\n", prefix, sb->s_id, &vaf);  in ext2_msg()
103 void ext2_update_dynamic_rev(struct super_block *sb)  in ext2_update_dynamic_rev()  argument
105 	struct ext2_super_block *es = EXT2_SB(sb)->s_es;  in ext2_update_dynamic_rev()
110 	ext2_msg(sb, KERN_WARNING,  in ext2_update_dynamic_rev()
129 static int ext2_quota_off(struct super_block *sb, int type);
131 static void ext2_quota_off_umount(struct super_block *sb)  in ext2_quota_off_umount()  argument
136 		ext2_quota_off(sb, type);  in ext2_quota_off_umount()
139 static inline void ext2_quota_off_umount(struct super_block *sb)  in ext2_quota_off_umount()  argument
144 static void ext2_put_super (struct super_block * sb)  in ext2_put_super()  argument
148 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_put_super()
150 	ext2_quota_off_umount(sb);  in ext2_put_super()
155 	if (!sb_rdonly(sb)) {  in ext2_put_super()
161 		ext2_sync_super(sb, es, 1);  in ext2_put_super()
172 	sb->s_fs_info = NULL;  in ext2_put_super()
180 static struct inode *ext2_alloc_inode(struct super_block *sb)  in ext2_alloc_inode()  argument
183 	ei = alloc_inode_sb(sb, ext2_inode_cachep, GFP_KERNEL);  in ext2_alloc_inode()
238 	struct super_block *sb = root->d_sb;  in ext2_show_options()  local
239 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_show_options()
248 	if (test_opt(sb, MINIX_DF))  in ext2_show_options()
250 	if (test_opt(sb, GRPID))  in ext2_show_options()
252 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT2_DEFM_BSDGROUPS))  in ext2_show_options()
264 	if (test_opt(sb, ERRORS_RO)) {  in ext2_show_options()
272 	if (test_opt(sb, ERRORS_CONT))  in ext2_show_options()
274 	if (test_opt(sb, ERRORS_PANIC))  in ext2_show_options()
276 	if (test_opt(sb, NO_UID32))  in ext2_show_options()
278 	if (test_opt(sb, DEBUG))  in ext2_show_options()
280 	if (test_opt(sb, OLDALLOC))  in ext2_show_options()
284 	if (test_opt(sb, XATTR_USER))  in ext2_show_options()
286 	if (!test_opt(sb, XATTR_USER) &&  in ext2_show_options()
293 	if (test_opt(sb, POSIX_ACL))  in ext2_show_options()
295 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT2_DEFM_ACL))  in ext2_show_options()
299 	if (test_opt(sb, USRQUOTA))  in ext2_show_options()
302 	if (test_opt(sb, GRPQUOTA))  in ext2_show_options()
305 	if (test_opt(sb, XIP))  in ext2_show_options()
308 	if (test_opt(sb, DAX))  in ext2_show_options()
311 	if (!test_opt(sb, RESERVATION))  in ext2_show_options()
319 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data, size_t len, loff_t off…
320 static ssize_t ext2_quota_write(struct super_block *sb, int type, const char *data, size_t len, lof…
321 static int ext2_quota_on(struct super_block *sb, int type, int format_id,
359 static struct inode *ext2_nfs_get_inode(struct super_block *sb,  in ext2_nfs_get_inode()  argument
364 	if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)  in ext2_nfs_get_inode()
366 	if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))  in ext2_nfs_get_inode()
374 	inode = ext2_iget(sb, ino);  in ext2_nfs_get_inode()
385 static struct dentry *ext2_fh_to_dentry(struct super_block *sb, struct fid *fid,  in ext2_fh_to_dentry()  argument
388 	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,  in ext2_fh_to_dentry()
392 static struct dentry *ext2_fh_to_parent(struct super_block *sb, struct fid *fid,  in ext2_fh_to_parent()  argument
395 	return generic_fh_to_parent(sb, fid, fh_len, fh_type,  in ext2_fh_to_parent()
467 static int parse_options(char *options, struct super_block *sb,  in parse_options()  argument
503 				ext2_msg(sb, KERN_ERR, "Invalid uid value %d", option);  in parse_options()
514 				ext2_msg(sb, KERN_ERR, "Invalid gid value %d", option);  in parse_options()
551 			ext2_msg(sb, KERN_INFO,  in parse_options()
564 			ext2_msg(sb, KERN_INFO, "(no)user_xattr options"  in parse_options()
578 			ext2_msg(sb, KERN_INFO,  in parse_options()
583 			ext2_msg(sb, KERN_INFO, "use dax instead of xip");  in parse_options()
588 			ext2_msg(sb, KERN_WARNING,  in parse_options()
592 			ext2_msg(sb, KERN_INFO, "dax option not supported");  in parse_options()
609 			ext2_msg(sb, KERN_INFO,  in parse_options()
616 			ext2_msg(sb, KERN_INFO, "reservations ON");  in parse_options()
620 			ext2_msg(sb, KERN_INFO, "reservations OFF");  in parse_options()
631 static int ext2_setup_super (struct super_block * sb,  in ext2_setup_super()  argument
636 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_setup_super()
639 		ext2_msg(sb, KERN_ERR,  in ext2_setup_super()
647 		ext2_msg(sb, KERN_WARNING,  in ext2_setup_super()
651 		ext2_msg(sb, KERN_WARNING,  in ext2_setup_super()
657 		ext2_msg(sb, KERN_WARNING,  in ext2_setup_super()
664 		ext2_msg(sb, KERN_WARNING,  in ext2_setup_super()
670 	if (test_opt (sb, DEBUG))  in ext2_setup_super()
671 		ext2_msg(sb, KERN_INFO, "%s, %s, bs=%lu, gc=%lu, "  in ext2_setup_super()
673 			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,  in ext2_setup_super()
675 			EXT2_BLOCKS_PER_GROUP(sb),  in ext2_setup_super()
676 			EXT2_INODES_PER_GROUP(sb),  in ext2_setup_super()
681 static int ext2_check_descriptors(struct super_block *sb)  in ext2_check_descriptors()  argument
684 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_check_descriptors()
689 		struct ext2_group_desc *gdp = ext2_get_group_desc(sb, i, NULL);  in ext2_check_descriptors()
690 		ext2_fsblk_t first_block = ext2_group_first_block_no(sb, i);  in ext2_check_descriptors()
691 		ext2_fsblk_t last_block = ext2_group_last_block_no(sb, i);  in ext2_check_descriptors()
696 			ext2_error (sb, "ext2_check_descriptors",  in ext2_check_descriptors()
705 			ext2_error (sb, "ext2_check_descriptors",  in ext2_check_descriptors()
715 			ext2_error (sb, "ext2_check_descriptors",  in ext2_check_descriptors()
787 static unsigned long descriptor_loc(struct super_block *sb,  in descriptor_loc()  argument
791 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in descriptor_loc()
796 	if (!EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_META_BG) ||  in descriptor_loc()
801 	return ext2_group_first_block_no(sb, bg) + ext2_bg_has_super(sb, bg);  in descriptor_loc()
804 static int ext2_fill_super(struct super_block *sb, void *data, int silent)  in ext2_fill_super()  argument
833 	sb->s_fs_info = sbi;  in ext2_fill_super()
835 	sbi->s_daxdev = fs_dax_get_by_bdev(sb->s_bdev, &sbi->s_dax_part_off,  in ext2_fill_super()
848 	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);  in ext2_fill_super()
850 		ext2_msg(sb, KERN_ERR, "error: unable to set blocksize");  in ext2_fill_super()
865 	if (!(bh = sb_bread(sb, logic_sb_block))) {  in ext2_fill_super()
866 		ext2_msg(sb, KERN_ERR, "error: unable to read superblock");  in ext2_fill_super()
875 	sb->s_magic = le16_to_cpu(es->s_magic);  in ext2_fill_super()
877 	if (sb->s_magic != EXT2_SUPER_MAGIC)  in ext2_fill_super()
910 	if (!parse_options((char *) data, sb, &opts))  in ext2_fill_super()
917 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |  in ext2_fill_super()
918 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);  in ext2_fill_super()
919 	sb->s_iflags |= SB_I_CGROUPWB;  in ext2_fill_super()
922 	    (EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||  in ext2_fill_super()
923 	     EXT2_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||  in ext2_fill_super()
924 	     EXT2_HAS_INCOMPAT_FEATURE(sb, ~0U)))  in ext2_fill_super()
925 		ext2_msg(sb, KERN_WARNING,  in ext2_fill_super()
933 	features = EXT2_HAS_INCOMPAT_FEATURE(sb, ~EXT2_FEATURE_INCOMPAT_SUPP);  in ext2_fill_super()
935 		ext2_msg(sb, KERN_ERR,	"error: couldn't mount because of "  in ext2_fill_super()
940 	if (!sb_rdonly(sb) && (features = EXT2_HAS_RO_COMPAT_FEATURE(sb, ~EXT2_FEATURE_RO_COMPAT_SUPP))){  in ext2_fill_super()
941 		ext2_msg(sb, KERN_ERR, "error: couldn't mount RDWR because of "  in ext2_fill_super()
949 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
956 	if (test_opt(sb, DAX)) {  in ext2_fill_super()
958 			ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
962 			ext2_msg(sb, KERN_ERR, "unsupported blocksize for DAX\n");  in ext2_fill_super()
968 	if (sb->s_blocksize != blocksize) {  in ext2_fill_super()
971 		if (!sb_set_blocksize(sb, blocksize)) {  in ext2_fill_super()
972 			ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
979 		bh = sb_bread(sb, logic_sb_block);  in ext2_fill_super()
981 			ext2_msg(sb, KERN_ERR, "error: couldn't read"  in ext2_fill_super()
988 			ext2_msg(sb, KERN_ERR, "error: magic mismatch");  in ext2_fill_super()
993 	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);  in ext2_fill_super()
994 	sb->s_max_links = EXT2_LINK_MAX;  in ext2_fill_super()
995 	sb->s_time_min = S32_MIN;  in ext2_fill_super()
996 	sb->s_time_max = S32_MAX;  in ext2_fill_super()
1007 			ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1017 	sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);  in ext2_fill_super()
1022 	sbi->s_desc_per_block = sb->s_blocksize /  in ext2_fill_super()
1027 		ilog2 (EXT2_ADDR_PER_BLOCK(sb));  in ext2_fill_super()
1029 		ilog2 (EXT2_DESC_PER_BLOCK(sb));  in ext2_fill_super()
1031 	if (sb->s_magic != EXT2_SUPER_MAGIC)  in ext2_fill_super()
1034 	if (sb->s_blocksize != bh->b_size) {  in ext2_fill_super()
1036 			ext2_msg(sb, KERN_ERR, "error: unsupported blocksize");  in ext2_fill_super()
1041 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1043 			le32_to_cpu(es->s_log_frag_size), sb->s_blocksize_bits);  in ext2_fill_super()
1047 	if (sbi->s_blocks_per_group > sb->s_blocksize * 8) {  in ext2_fill_super()
1048 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1055 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1061 	    sbi->s_inodes_per_group > sb->s_blocksize * 8) {  in ext2_fill_super()
1062 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1067 	if (sb_bdev_nr_blocks(sb) < le32_to_cpu(es->s_blocks_count)) {  in ext2_fill_super()
1068 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1071 			 (unsigned)sb_bdev_nr_blocks(sb));  in ext2_fill_super()
1077 					/ EXT2_BLOCKS_PER_GROUP(sb)) + 1;  in ext2_fill_super()
1080 		ext2_msg(sb, KERN_ERR, "error: invalid #inodes: %u vs computed %llu",  in ext2_fill_super()
1085 	db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /  in ext2_fill_super()
1086 		   EXT2_DESC_PER_BLOCK(sb);  in ext2_fill_super()
1092 		ext2_msg(sb, KERN_ERR, "error: not enough memory");  in ext2_fill_super()
1099 		ext2_msg(sb, KERN_ERR, "error: not enough memory");  in ext2_fill_super()
1103 		block = descriptor_loc(sb, logic_sb_block, i);  in ext2_fill_super()
1104 		sbi->s_group_desc[i] = sb_bread(sb, block);  in ext2_fill_super()
1108 			ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1113 	if (!ext2_check_descriptors (sb)) {  in ext2_fill_super()
1114 		ext2_msg(sb, KERN_ERR, "group descriptors corrupted");  in ext2_fill_super()
1134 	ext2_rsv_window_add(sb, &sbi->s_rsv_window_head);  in ext2_fill_super()
1137 				ext2_count_free_blocks(sb), GFP_KERNEL);  in ext2_fill_super()
1140 				ext2_count_free_inodes(sb), GFP_KERNEL);  in ext2_fill_super()
1144 				ext2_count_dirs(sb), GFP_KERNEL);  in ext2_fill_super()
1148 		ext2_msg(sb, KERN_ERR, "error: insufficient memory");  in ext2_fill_super()
1156 		ext2_msg(sb, KERN_ERR, "Failed to create ea_block_cache");  in ext2_fill_super()
1163 	sb->s_op = &ext2_sops;  in ext2_fill_super()
1164 	sb->s_export_op = &ext2_export_ops;  in ext2_fill_super()
1165 	sb->s_xattr = ext2_xattr_handlers;  in ext2_fill_super()
1168 	sb->dq_op = &dquot_operations;  in ext2_fill_super()
1169 	sb->s_qcop = &ext2_quotactl_ops;  in ext2_fill_super()
1170 	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;  in ext2_fill_super()
1173 	root = ext2_iget(sb, EXT2_ROOT_INO);  in ext2_fill_super()
1180 		ext2_msg(sb, KERN_ERR, "error: corrupt root inode, run e2fsck");  in ext2_fill_super()
1184 	sb->s_root = d_make_root(root);  in ext2_fill_super()
1185 	if (!sb->s_root) {  in ext2_fill_super()
1186 		ext2_msg(sb, KERN_ERR, "error: get root inode failed");  in ext2_fill_super()
1190 	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))  in ext2_fill_super()
1191 		ext2_msg(sb, KERN_WARNING,  in ext2_fill_super()
1193 	if (ext2_setup_super (sb, es, sb_rdonly(sb)))  in ext2_fill_super()
1194 		sb->s_flags |= SB_RDONLY;  in ext2_fill_super()
1195 	ext2_write_super(sb);  in ext2_fill_super()
1200 		ext2_msg(sb, KERN_ERR,  in ext2_fill_super()
1202 			sb->s_id);  in ext2_fill_super()
1219 	sb->s_fs_info = NULL;  in ext2_fill_super()
1225 static void ext2_clear_super_error(struct super_block *sb)  in ext2_clear_super_error()  argument
1227 	struct buffer_head *sbh = EXT2_SB(sb)->s_sbh;  in ext2_clear_super_error()
1238 		ext2_msg(sb, KERN_ERR,  in ext2_clear_super_error()
1245 void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,  in ext2_sync_super()  argument
1248 	ext2_clear_super_error(sb);  in ext2_sync_super()
1249 	spin_lock(&EXT2_SB(sb)->s_lock);  in ext2_sync_super()
1250 	es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb));  in ext2_sync_super()
1251 	es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb));  in ext2_sync_super()
1254 	spin_unlock(&EXT2_SB(sb)->s_lock);  in ext2_sync_super()
1255 	mark_buffer_dirty(EXT2_SB(sb)->s_sbh);  in ext2_sync_super()
1257 		sync_dirty_buffer(EXT2_SB(sb)->s_sbh);  in ext2_sync_super()
1270 static int ext2_sync_fs(struct super_block *sb, int wait)  in ext2_sync_fs()  argument
1272 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_sync_fs()
1273 	struct ext2_super_block *es = EXT2_SB(sb)->s_es;  in ext2_sync_fs()
1279 	dquot_writeback_dquots(sb, -1);  in ext2_sync_fs()
1287 	ext2_sync_super(sb, es, wait);  in ext2_sync_fs()
1291 static int ext2_freeze(struct super_block *sb)  in ext2_freeze()  argument
1293 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_freeze()
1300 	if (atomic_long_read(&sb->s_remove_count)) {  in ext2_freeze()
1301 		ext2_sync_fs(sb, 1);  in ext2_freeze()
1308 	ext2_sync_super(sb, sbi->s_es, 1);  in ext2_freeze()
1313 static int ext2_unfreeze(struct super_block *sb)  in ext2_unfreeze()  argument
1316 	ext2_write_super(sb);  in ext2_unfreeze()
1321 static void ext2_write_super(struct super_block *sb)  in ext2_write_super()  argument
1323 	if (!sb_rdonly(sb))  in ext2_write_super()
1324 		ext2_sync_fs(sb, 1);  in ext2_write_super()
1327 static int ext2_remount (struct super_block * sb, int * flags, char * data)  in ext2_remount()  argument
1329 	struct ext2_sb_info * sbi = EXT2_SB(sb);  in ext2_remount()
1334 	sync_filesystem(sb);  in ext2_remount()
1342 	if (!parse_options(data, sb, &new_opts))  in ext2_remount()
1348 		ext2_msg(sb, KERN_WARNING, "warning: refusing change of "  in ext2_remount()
1352 	if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))  in ext2_remount()
1367 		err = dquot_suspend(sb, -1);  in ext2_remount()
1371 		ext2_sync_super(sb, es, 1);  in ext2_remount()
1373 		__le32 ret = EXT2_HAS_RO_COMPAT_FEATURE(sb,  in ext2_remount()
1377 			ext2_msg(sb, KERN_WARNING,  in ext2_remount()
1389 		if (!ext2_setup_super (sb, es, 0))  in ext2_remount()
1390 			sb->s_flags &= ~SB_RDONLY;  in ext2_remount()
1393 		ext2_write_super(sb);  in ext2_remount()
1395 		dquot_resume(sb, -1);  in ext2_remount()
1403 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |  in ext2_remount()
1404 		(test_opt(sb, POSIX_ACL) ? SB_POSIXACL : 0);  in ext2_remount()
1412 	struct super_block *sb = dentry->d_sb;  in ext2_statfs()  local
1413 	struct ext2_sb_info *sbi = EXT2_SB(sb);  in ext2_statfs()
1418 	if (test_opt (sb, MINIX_DF))  in ext2_statfs()
1442 			overhead += ext2_bg_has_super(sb, i) +  in ext2_statfs()
1443 				ext2_bg_num_gdb(sb, i);  in ext2_statfs()
1457 	buf->f_bsize = sb->s_blocksize;  in ext2_statfs()
1459 	buf->f_bfree = ext2_count_free_blocks(sb);  in ext2_statfs()
1465 	buf->f_ffree = ext2_count_free_inodes(sb);  in ext2_statfs()
1485 static ssize_t ext2_quota_read(struct super_block *sb, int type, char *data,  in ext2_quota_read()  argument
1488 	struct inode *inode = sb_dqopt(sb)->files[type];  in ext2_quota_read()
1489 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);  in ext2_quota_read()
1491 	int offset = off & (sb->s_blocksize - 1);  in ext2_quota_read()
1504 		tocopy = min_t(size_t, sb->s_blocksize - offset, toread);  in ext2_quota_read()
1507 		tmp_bh.b_size = sb->s_blocksize;  in ext2_quota_read()
1514 			bh = sb_bread(sb, tmp_bh.b_blocknr);  in ext2_quota_read()
1529 static ssize_t ext2_quota_write(struct super_block *sb, int type,  in ext2_quota_write()  argument
1532 	struct inode *inode = sb_dqopt(sb)->files[type];  in ext2_quota_write()
1533 	sector_t blk = off >> EXT2_BLOCK_SIZE_BITS(sb);  in ext2_quota_write()
1535 	int offset = off & (sb->s_blocksize - 1);  in ext2_quota_write()
1542 		tocopy = min_t(size_t, sb->s_blocksize - offset, towrite);  in ext2_quota_write()
1545 		tmp_bh.b_size = sb->s_blocksize;  in ext2_quota_write()
1549 		if (offset || tocopy != EXT2_BLOCK_SIZE(sb))  in ext2_quota_write()
1550 			bh = sb_bread(sb, tmp_bh.b_blocknr);  in ext2_quota_write()
1552 			bh = sb_getblk(sb, tmp_bh.b_blocknr);  in ext2_quota_write()
1580 static int ext2_quota_on(struct super_block *sb, int type, int format_id,  in ext2_quota_on()  argument
1586 	err = dquot_quota_on(sb, type, format_id, path);  in ext2_quota_on()
1601 static int ext2_quota_off(struct super_block *sb, int type)  in ext2_quota_off()  argument
1603 	struct inode *inode = sb_dqopt(sb)->files[type];  in ext2_quota_off()
1609 	err = dquot_quota_off(sb, type);  in ext2_quota_off()
1622 	return dquot_quota_off(sb, type);  in ext2_quota_off()