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: [<ffffffff815c7dfc>] dump_stack+0x51/0x6d [<ffffffff8106ce8c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff81202008>] ? ext4_ioctl+0x9e8/0xeb0 [<ffffffff8106ceda>] warn_slowpath_null+0x1a/0x20 [<ffffffff8122867e>] ext4_journal_check_start+0x4e/0xa0 [<ffffffff81228c10>] __ext4_journal_start_sb+0x90/0x110 [<ffffffff81202008>] ext4_ioctl+0x9e8/0xeb0 [<ffffffff8107b0bd>] ? ptrace_stop+0x24d/0x2f0 [<ffffffff81088530>] ? alloc_pid+0x480/0x480 [<ffffffff8107b1f2>] ? ptrace_do_notify+0x92/0xb0 [<ffffffff81186545>] do_vfs_ioctl+0x4e5/0x550 [<ffffffff815cdbcb>] ? _raw_spin_unlock_irq+0x2b/0x40 [<ffffffff81186603>] SyS_ioctl+0x53/0x80 [<ffffffff815ce2ce>] tracesys+0xd0/0xd5 Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> --- fs/ext4/ioctl.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 0f2252e..3d5de16 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -532,9 +532,17 @@ group_add_out: } 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; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html