From 007649375f6af242d5b1df2c15996949714303ba Mon Sep 17 00:00:00 2001 From: Azat Khuzhin Date: Mon, 7 Apr 2014 10:54:20 -0400 Subject: [PATCH] ext4: initialize multi-block allocator before checking block descriptors With EXT4FS_DEBUG ext4_count_free_clusters() will call ext4_read_block_bitmap() without s_group_info initialized, so we need to initialize multi-block allocator before. And dependencies that must be solved, to allow this: - multi-block allocator needs in group descriptors - need to install s_op before initializing multi-block allocator, because in ext4_mb_init_backend() new inode is created. - initialize number of group desc blocks (s_gdb_count) otherwise number of clusters returned by ext4_free_clusters_after_init() is not correct. (see ext4_bg_num_gdb_nometa()) Here is the stack backtrace: (gdb) bt #0 ext4_get_group_info (group=0, sb=0xffff880079a10000) at ext4.h:2430 #1 ext4_validate_block_bitmap (sb=sb@entry=0xffff880079a10000, desc=desc@entry=0xffff880056510000, block_group=block_group@entry=0, bh=bh@entry=0xffff88007bf2b2d8) at balloc.c:358 #2 0xffffffff81232202 in ext4_wait_block_bitmap (sb=sb@entry=0xffff880079a10000, block_group=block_group@entry=0, bh=bh@entry=0xffff88007bf2b2d8) at balloc.c:476 #3 0xffffffff81232eaf in ext4_read_block_bitmap (sb=sb@entry=0xffff880079a10000, block_group=block_group@entry=0) at balloc.c:489 #4 0xffffffff81232fc0 in ext4_count_free_clusters (sb=sb@entry=0xffff880079a10000) at balloc.c:665 #5 0xffffffff81259ffa in ext4_check_descriptors (first_not_zeroed=, sb=0xffff880079a10000) at super.c:2143 #6 ext4_fill_super (sb=sb@entry=0xffff880079a10000, data=, data@entry=0x0 , silent=silent@entry=0) at super.c:3851 ... Signed-off-by: Azat Khuzhin Signed-off-by: "Theodore Ts'o" --- fs/ext4/super.c | 51 ++++++++++++++++++++++++++----------------------- 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f3c667091618..6f9e6fadac04 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3869,19 +3869,38 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) goto failed_mount2; } } + + /* + * set up enough so that it can read an inode, + * and create new inode for buddy allocator + */ + sbi->s_gdb_count = db_count; + if (!test_opt(sb, NOLOAD) && + EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) + sb->s_op = &ext4_sops; + else + sb->s_op = &ext4_nojournal_sops; + + ext4_ext_init(sb); + err = ext4_mb_init(sb); + if (err) { + ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)", + err); + goto failed_mount2; + } + if (!ext4_check_descriptors(sb, &first_not_zeroed)) { ext4_msg(sb, KERN_ERR, "group descriptors corrupted!"); - goto failed_mount2; + goto failed_mount2a; } if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) if (!ext4_fill_flex_info(sb)) { ext4_msg(sb, KERN_ERR, "unable to initialize " "flex_bg meta info!"); - goto failed_mount2; + goto failed_mount2a; } - sbi->s_gdb_count = db_count; get_random_bytes(&sbi->s_next_generation, sizeof(u32)); spin_lock_init(&sbi->s_next_gen_lock); @@ -3916,14 +3935,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) sbi->s_stripe = ext4_get_stripe_size(sbi); sbi->s_extent_max_zeroout_kb = 32; - /* - * set up enough so that it can read an inode - */ - if (!test_opt(sb, NOLOAD) && - EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) - sb->s_op = &ext4_sops; - else - sb->s_op = &ext4_nojournal_sops; sb->s_export_op = &ext4_export_ops; sb->s_xattr = ext4_xattr_handlers; #ifdef CONFIG_QUOTA @@ -4113,21 +4124,13 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) if (err) { ext4_msg(sb, KERN_ERR, "failed to reserve %llu clusters for " "reserved pool", ext4_calculate_resv_clusters(sb)); - goto failed_mount4a; + goto failed_mount5; } err = ext4_setup_system_zone(sb); if (err) { ext4_msg(sb, KERN_ERR, "failed to initialize system " "zone (%d)", err); - goto failed_mount4a; - } - - ext4_ext_init(sb); - err = ext4_mb_init(sb); - if (err) { - ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)", - err); goto failed_mount5; } @@ -4204,11 +4207,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) failed_mount7: ext4_unregister_li_request(sb); failed_mount6: - ext4_mb_release(sb); -failed_mount5: - ext4_ext_release(sb); ext4_release_system_zone(sb); -failed_mount4a: +failed_mount5: dput(sb->s_root); sb->s_root = NULL; failed_mount4: @@ -4232,11 +4232,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) percpu_counter_destroy(&sbi->s_extent_cache_cnt); if (sbi->s_mmp_tsk) kthread_stop(sbi->s_mmp_tsk); +failed_mount2a: + ext4_mb_release(sb); failed_mount2: for (i = 0; i < db_count; i++) brelse(sbi->s_group_desc[i]); ext4_kvfree(sbi->s_group_desc); failed_mount: + ext4_ext_release(sb); if (sbi->s_chksum_driver) crypto_free_shash(sbi->s_chksum_driver); if (sbi->s_proc) {