On Tue 18-10-22 10:27:01, Ye Bin wrote: > Syzkaller report issue as follows: > EXT4-fs (loop0): Free/Dirty block details > EXT4-fs (loop0): free_blocks=0 > EXT4-fs (loop0): dirty_blocks=0 > EXT4-fs (loop0): Block reservation details > EXT4-fs (loop0): i_reserved_data_blocks=0 > EXT4-fs warning (device loop0): ext4_da_release_space:1527: ext4_da_release_space: ino 18, to_free 1 with only 0 reserved data blocks > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 92 at fs/ext4/inode.c:1528 ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1524 > Modules linked in: > CPU: 0 PID: 92 Comm: kworker/u4:4 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 > Workqueue: writeback wb_workfn (flush-7:0) > RIP: 0010:ext4_da_release_space+0x25e/0x370 fs/ext4/inode.c:1528 > RSP: 0018:ffffc900015f6c90 EFLAGS: 00010296 > RAX: 42215896cd52ea00 RBX: 0000000000000000 RCX: 42215896cd52ea00 > RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000 > RBP: 1ffff1100e907d96 R08: ffffffff816aa79d R09: fffff520002bece5 > R10: fffff520002bece5 R11: 1ffff920002bece4 R12: ffff888021fd2000 > R13: ffff88807483ecb0 R14: 0000000000000001 R15: ffff88807483e740 > FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00005555569ba628 CR3: 000000000c88e000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > ext4_es_remove_extent+0x1ab/0x260 fs/ext4/extents_status.c:1461 > mpage_release_unused_pages+0x24d/0xef0 fs/ext4/inode.c:1589 > ext4_writepages+0x12eb/0x3be0 fs/ext4/inode.c:2852 > do_writepages+0x3c3/0x680 mm/page-writeback.c:2469 > __writeback_single_inode+0xd1/0x670 fs/fs-writeback.c:1587 > writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1870 > wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2044 > wb_do_writeback fs/fs-writeback.c:2187 [inline] > wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2227 > process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 > worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 > kthread+0x266/0x300 kernel/kthread.c:376 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 > </TASK> > > Above issue may happens as follows: > ext4_da_write_begin > ext4_create_inline_data > ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); > ext4_set_inode_flag(inode, EXT4_INODE_INLINE_DATA); > __ext4_ioctl > ext4_ext_migrate -> will lead to eh->eh_entries not zero, and set extent flag > ext4_da_write_begin > ext4_da_convert_inline_data_to_extent > ext4_da_write_inline_data_begin > ext4_da_map_blocks > ext4_insert_delayed_block > if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) > if (!ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk)) > ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk)); -> will return 1 > allocated = true; > ext4_es_insert_delayed_block(inode, lblk, allocated); > ext4_writepages > mpage_map_and_submit_extent(handle, &mpd, &give_up_on_write); -> return -ENOSPC > mpage_release_unused_pages(&mpd, give_up_on_write); -> give_up_on_write == 1 > ext4_es_remove_extent > ext4_da_release_space(inode, reserved); > if (unlikely(to_free > ei->i_reserved_data_blocks)) > -> to_free == 1 but ei->i_reserved_data_blocks == 0 > -> then trigger warning as above > > To solve above issue, forbid inode do migrate which has inline data. > > Reported-by: syzbot+c740bb18df70ad00952e@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx> Yeah, makes sense. Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > fs/ext4/migrate.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c > index 0a220ec9862d..a19a9661646e 100644 > --- a/fs/ext4/migrate.c > +++ b/fs/ext4/migrate.c > @@ -424,7 +424,8 @@ int ext4_ext_migrate(struct inode *inode) > * already is extent-based, error out. > */ > if (!ext4_has_feature_extents(inode->i_sb) || > - (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) > + ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) || > + ext4_has_inline_data(inode)) > return -EINVAL; > > if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) > -- > 2.31.1 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
