• Darrick J. Wong's avatar
    xfs: fix missing ILOCK unlock when xfs_setattr_nonsize fails due to EDQUOT · 1fb254aa
    Darrick J. Wong authored
    Benjamin Moody reported to Debian that XFS partially wedges when a chgrp
    fails on account of being out of disk quota.  I ran his reproducer
    script:
    
    # adduser dummy
    # adduser dummy plugdev
    
    # dd if=/dev/zero bs=1M count=100 of=test.img
    # mkfs.xfs test.img
    # mount -t xfs -o gquota test.img /mnt
    # mkdir -p /mnt/dummy
    # chown -c dummy /mnt/dummy
    # xfs_quota -xc 'limit -g bsoft=100k bhard=100k plugdev' /mnt
    
    (and then as user dummy)
    
    $ dd if=/dev/urandom bs=1M count=50 of=/mnt/dummy/foo
    $ chgrp plugdev /mnt/dummy/foo
    
    and saw:
    
    ================================================
    WARNING: lock held when returning to user space!
    5.3.0-rc5 #rc5 Tainted: G        W
    ------------------------------------------------
    chgrp/47006 is leaving the kernel with locks still held!
    1 lock held by chgrp/47006:
     #0: 000000006664ea2d (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0xd2/0x290 [xfs]
    
    ...which is clearly caused by xfs_setattr_nonsize failing to unlock the
    ILOCK after the xfs_qm_vop_chown_reserve call fails.  Add the missing
    unlock.
    
    Reported-by: benjamin.moody@gmail.com
    Fixes: 253f4911 ("xfs: better xfs_trans_alloc interface")
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
    Tested-by: default avatarSalvatore Bonaccorso <carnil@debian.org>
    1fb254aa
xfs_iops.c 33.3 KB