From 72cc870f5feeffcedf59ff673071ab4c87dc65fb Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Fri, 3 Oct 2014 12:47:23 -0400 Subject: [PATCH] ext4: grab missed write_count for EXT4_IOC_SWAP_BOOT commit 3e67cfad22230ebed85c56cbe413876f33fea82b upstream. Otherwise this provokes complain like follows: WARNING: CPU: 12 PID: 5795 at fs/ext4/ext4_jbd2.c:48 ext4_journal_check_start+0x4e/0xa0() Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod CPU: 12 PID: 5795 Comm: python Not tainted 3.17.0-rc2-00175-gae5344f #158 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 0000000000000030 ffff8808116cfd28 ffffffff815c7dfc 0000000000000030 0000000000000000 ffff8808116cfd68 ffffffff8106ce8c ffff8808116cfdc8 ffff880813b16000 ffff880806ad6ae8 ffffffff81202008 0000000000000000 Call Trace: [] dump_stack+0x51/0x6d [] warn_slowpath_common+0x8c/0xc0 [] ? ext4_ioctl+0x9e8/0xeb0 [] warn_slowpath_null+0x1a/0x20 [] ext4_journal_check_start+0x4e/0xa0 [] __ext4_journal_start_sb+0x90/0x110 [] ext4_ioctl+0x9e8/0xeb0 [] ? ptrace_stop+0x24d/0x2f0 [] ? alloc_pid+0x480/0x480 [] ? ptrace_do_notify+0x92/0xb0 [] do_vfs_ioctl+0x4e5/0x550 [] ? _raw_spin_unlock_irq+0x2b/0x40 [] SyS_ioctl+0x53/0x80 [] tracesys+0xd0/0xd5 Reviewed-by: Jan Kara Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ioctl.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a2a837f0040743..f115b9670ed86d 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -544,9 +544,17 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) } case EXT4_IOC_SWAP_BOOT: + { + int err; if (!(filp->f_mode & FMODE_WRITE)) return -EBADF; - return swap_inode_boot_loader(sb, inode); + err = mnt_want_write_file(filp); + if (err) + return err; + err = swap_inode_boot_loader(sb, inode); + mnt_drop_write_file(filp); + return err; + } case EXT4_IOC_RESIZE_FS: { ext4_fsblk_t n_blocks_count;