| From f4534c9fc94d22383f187b9409abb3f9df2e3db3 Mon Sep 17 00:00:00 2001 |
| From: Ye Bin <yebin10@huawei.com> |
| Date: Sat, 26 Mar 2022 14:53:51 +0800 |
| Subject: ext4: fix warning in ext4_handle_inode_extension |
| |
| From: Ye Bin <yebin10@huawei.com> |
| |
| commit f4534c9fc94d22383f187b9409abb3f9df2e3db3 upstream. |
| |
| We got issue as follows: |
| EXT4-fs error (device loop0) in ext4_reserve_inode_write:5741: Out of memory |
| EXT4-fs error (device loop0): ext4_setattr:5462: inode #13: comm syz-executor.0: mark_inode_dirty error |
| EXT4-fs error (device loop0) in ext4_setattr:5519: Out of memory |
| EXT4-fs error (device loop0): ext4_ind_map_blocks:595: inode #13: comm syz-executor.0: Can't allocate blocks for non-extent mapped inodes with bigalloc |
| ------------[ cut here ]------------ |
| WARNING: CPU: 1 PID: 4361 at fs/ext4/file.c:301 ext4_file_write_iter+0x11c9/0x1220 |
| Modules linked in: |
| CPU: 1 PID: 4361 Comm: syz-executor.0 Not tainted 5.10.0+ #1 |
| RIP: 0010:ext4_file_write_iter+0x11c9/0x1220 |
| RSP: 0018:ffff924d80b27c00 EFLAGS: 00010282 |
| RAX: ffffffff815a3379 RBX: 0000000000000000 RCX: 000000003b000000 |
| RDX: ffff924d81601000 RSI: 00000000000009cc RDI: 00000000000009cd |
| RBP: 000000000000000d R08: ffffffffbc5a2c6b R09: 0000902e0e52a96f |
| R10: ffff902e2b7c1b40 R11: ffff902e2b7c1b40 R12: 000000000000000a |
| R13: 0000000000000001 R14: ffff902e0e52aa10 R15: ffffffffffffff8b |
| FS: 00007f81a7f65700(0000) GS:ffff902e3bc80000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: ffffffffff600400 CR3: 000000012db88001 CR4: 00000000003706e0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| do_iter_readv_writev+0x2e5/0x360 |
| do_iter_write+0x112/0x4c0 |
| do_pwritev+0x1e5/0x390 |
| __x64_sys_pwritev2+0x7e/0xa0 |
| do_syscall_64+0x37/0x50 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| |
| Above issue may happen as follows: |
| Assume |
| inode.i_size=4096 |
| EXT4_I(inode)->i_disksize=4096 |
| |
| step 1: set inode->i_isize = 8192 |
| ext4_setattr |
| if (attr->ia_size != inode->i_size) |
| EXT4_I(inode)->i_disksize = attr->ia_size; |
| rc = ext4_mark_inode_dirty |
| ext4_reserve_inode_write |
| ext4_get_inode_loc |
| __ext4_get_inode_loc |
| sb_getblk --> return -ENOMEM |
| ... |
| if (!error) ->will not update i_size |
| i_size_write(inode, attr->ia_size); |
| Now: |
| inode.i_size=4096 |
| EXT4_I(inode)->i_disksize=8192 |
| |
| step 2: Direct write 4096 bytes |
| ext4_file_write_iter |
| ext4_dio_write_iter |
| iomap_dio_rw ->return error |
| if (extend) |
| ext4_handle_inode_extension |
| WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize); |
| ->Then trigger warning. |
| |
| To solve above issue, if mark inode dirty failed in ext4_setattr just |
| set 'EXT4_I(inode)->i_disksize' with old value. |
| |
| Signed-off-by: Ye Bin <yebin10@huawei.com> |
| Link: https://lore.kernel.org/r/20220326065351.761952-1-yebin10@huawei.com |
| Signed-off-by: Theodore Ts'o <tytso@mit.edu> |
| Cc: stable@kernel.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/ext4/inode.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/fs/ext4/inode.c |
| +++ b/fs/ext4/inode.c |
| @@ -5389,6 +5389,7 @@ int ext4_setattr(struct user_namespace * |
| if (attr->ia_valid & ATTR_SIZE) { |
| handle_t *handle; |
| loff_t oldsize = inode->i_size; |
| + loff_t old_disksize; |
| int shrink = (attr->ia_size < inode->i_size); |
| |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
| @@ -5460,6 +5461,7 @@ int ext4_setattr(struct user_namespace * |
| inode->i_sb->s_blocksize_bits); |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| + old_disksize = EXT4_I(inode)->i_disksize; |
| EXT4_I(inode)->i_disksize = attr->ia_size; |
| rc = ext4_mark_inode_dirty(handle, inode); |
| if (!error) |
| @@ -5471,6 +5473,8 @@ int ext4_setattr(struct user_namespace * |
| */ |
| if (!error) |
| i_size_write(inode, attr->ia_size); |
| + else |
| + EXT4_I(inode)->i_disksize = old_disksize; |
| up_write(&EXT4_I(inode)->i_data_sem); |
| ext4_journal_stop(handle); |
| if (error) |