System becomes unresponsive for a minute while accessing XFS filesystem.

Issue

• Box hangs for minutes at a time on any access to an xfs filesystem. Following backtrace is seen in dmesg

INFO: task java:10517 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
java          D 0000000000000009     0 10517  10510 0x00000080
 ffff880671edb758 0000000000000082 0000000000000000 ffff880028354280
 ffff880676730000 ffff880028356700 ffff880672e63a40 00000000ffffffff
 ffff880674b09098 ffff880671edbfd8 000000000000fb88 ffff880674b09098
Call Trace:
 [<ffffffff8150ea05>] schedule_timeout+0x215/0x2e0
 [<ffffffffa02a94a5>] ? xfs_buf_cond_lock+0x25/0x80 [xfs]
 [<ffffffffa02aa85f>] ? _xfs_buf_find+0xcf/0x230 [xfs]
 [<ffffffff8150f922>] __down+0x72/0xb0
 [<ffffffffa02aa875>] ? _xfs_buf_find+0xe5/0x230 [xfs]
 [<ffffffff8109ca61>] down+0x41/0x50
 [<ffffffffa02aa6e1>] xfs_buf_lock+0x51/0x100 [xfs]
 [<ffffffffa02aa875>] _xfs_buf_find+0xe5/0x230 [xfs]
 [<ffffffffa02aa9f4>] xfs_buf_get+0x34/0x1b0 [xfs]
 [<ffffffffa02a9db5>] ? xfs_buf_rele+0x55/0x100 [xfs]
 [<ffffffffa02ab07c>] xfs_buf_read+0x2c/0x100 [xfs]
 [<ffffffffa02a0937>] xfs_trans_read_buf+0x1f7/0x410 [xfs]
 [<ffffffffa02833f4>] xfs_read_agi+0x74/0x100 [xfs]
 [<ffffffffa02834ae>] xfs_ialloc_read_agi+0x2e/0x90 [xfs]
 [<ffffffffa0283793>] xfs_ialloc_ag_select+0x133/0x270 [xfs]
 [<ffffffffa0284e57>] xfs_dialloc+0x3d7/0x850 [xfs]
 [<ffffffffa028578d>] ? xfs_iunlock+0x9d/0xd0 [xfs]
 [<ffffffffa0288b90>] xfs_ialloc+0x60/0x6e0 [xfs]
 [<ffffffffa02a5e3a>] ? kmem_zone_zalloc+0x3a/0x50 [xfs]
 [<ffffffffa02a14c4>] xfs_dir_ialloc+0x74/0x2b0 [xfs]
 [<ffffffffa02a35a0>] xfs_create+0x440/0x640 [xfs]
 [<ffffffffa02b074d>] xfs_vn_mknod+0xad/0x1c0 [xfs]
 [<ffffffffa02b0873>] xfs_vn_mkdir+0x13/0x20 [xfs]
 [<ffffffff8118f197>] vfs_mkdir+0xa7/0x100
 [<ffffffff81192197>] sys_mkdirat+0xb7/0x130
 [<ffffffff81186c0b>] ? vfs_stat+0x1b/0x20
 [<ffffffff81186c34>] ? sys_newstat+0x24/0x50
 [<ffffffff81192228>] sys_mkdir+0x18/0x20
 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b