Description of problem:

From syslog during FC6T2 PXE/kickstart/NFS install:


<4>=============================================
<4>[ INFO: possible recursive locking detected ]
<4>---------------------------------------------
<4>anaconda/441 is trying to acquire lock:
<4> (&bdev->bd_mutex){--..}, at: [<c0464aeb>] __blkdev_put+0x1f/0x11f
<4>
<4>but task is already holding lock:
<4> (&bdev->bd_mutex){--..}, at: [<c0464d7e>] do_open+0x6b/0x3b2
<4>
<4>other info that might help us debug this:
<4>1 lock held by anaconda/441:
<4> #0:  (&bdev->bd_mutex){--..}, at: [<c0464d7e>] do_open+0x6b/0x3b2
<4>
<4>stack backtrace:
<4> [<c04037db>] show_trace_log_lvl+0x58/0x159
<4> [<c0403d9e>] show_trace+0xd/0x10
<4> [<c0403e3b>] dump_stack+0x19/0x1b
<4> [<c042bd47>] __lock_acquire+0x760/0x987
<4> [<c042c4df>] lock_acquire+0x4b/0x6c
<4> [<c05e8a16>] mutex_lock_nested+0xcb/0x214
<4> [<c0464aeb>] __blkdev_put+0x1f/0x11f
<4> [<c0464c04>] blkdev_put+0xa/0xc
<4> [<c0465056>] do_open+0x343/0x3b2
<4> [<c0465260>] blkdev_open+0x1f/0x48
<4> [<c045ca88>] __dentry_open+0xb8/0x186
<4> [<c045cbc4>] nameidata_to_filp+0x1c/0x2e
<4> [<c045cc05>] do_filp_open+0x2f/0x36
<4> [<c045cc4c>] do_sys_open+0x40/0xbb
<4> [<c045ccf3>] sys_open+0x16/0x18
<4> [<c0402e57>] syscall_call+0x7/0xb
<4>DWARF2 unwinder stuck at syscall_call+0x7/0xb
<4>Leftover inexact backtrace:
<4> [<c0403d9e>] show_trace+0xd/0x10
<4> [<c0403e3b>] dump_stack+0x19/0x1b
<4> [<c042bd47>] __lock_acquire+0x760/0x987
<4> [<c042c4df>] lock_acquire+0x4b/0x6c
<4> [<c05e8a16>] mutex_lock_nested+0xcb/0x214
<4> [<c0464aeb>] __blkdev_put+0x1f/0x11f
<4> [<c0464c04>] blkdev_put+0xa/0xc
<4> [<c0465056>] do_open+0x343/0x3b2
<4> [<c0465260>] blkdev_open+0x1f/0x48
<4> [<c045ca88>] __dentry_open+0xb8/0x186
<4> [<c045cbc4>] nameidata_to_filp+0x1c/0x2e
<4> [<c045cc05>] do_filp_open+0x2f/0x36
<4> [<c045cc4c>] do_sys_open+0x40/0xbb
<4> [<c045ccf3>] sys_open+0x16/0x18
<4> [<c0402e57>] syscall_call+0x7/0xb