2.6.23 regression: second access of empty ntfs file leads to D state hang

[Mike Galbraith <efault@gmx.de>]

Greetings,

I've stumbled across a 2.6.22->2.6.23 regression.  First md5sum access
of an empty NTFS file leads to kernel I/O error gripe, a second access
leaves md5sum hung.  2.6.22.10 has no trouble accessing this file.

Looking at the 22->23 diff, I don't see a quick and dirty stab
candidate, and since I'm preparing for a 5 week separation from my box
<twitch>, I doubt I'll have time to do a bisect.  /me punts.

root@Homer: md5sum '/windows/C/Dokumente und Einstellungen/All Users/Anwendungsdaten/Microsoft/Network/Connections/Pbk/rasphone.pbk'
md5sum: /windows/C/Dokumente und Einstellungen/All Users/Anwendungsdaten/Microsoft/Network/Connections/Pbk/rasphone.pbk: Input/output error

[  228.551859] NTFS-fs error (device hda1): ntfs_read_compressed_block(): ntfs_map_runlist() failed. Cannot read compression block.

[  401.721890] md5sum        D eee53d64     0  7249   7019
[  401.727155]        eee53d78 00200082 00000002 eee53d64 eee53d5c 00000000 e9b006b0 e9b00700 
[  401.735469]        5f6b3463 c0677060 c067a080 e9b00860 c180d080 00000000 c180d080 c180d108 
[  401.743991]        00000001 00200086 e9b006e0 00200086 f79ca640 eee53d94 0000b4d3 00200202 
[  401.752514] Call Trace:
[  401.755155]  [<c04b57bf>] io_schedule+0x1e/0x28
[  401.759711]  [<c015a269>] sync_page+0x34/0x3f
[  401.764102]  [<c04b5b78>] __wait_on_bit_lock+0x40/0x63
[  401.769281]  [<c015a221>] __lock_page+0x54/0x5c
[  401.773845]  [<c015a826>] do_generic_mapping_read+0x236/0x4e7
[  401.779629]  [<c015c165>] generic_file_aio_read+0xff/0x198
[  401.785138]  [<c017851c>] do_sync_read+0xd0/0x106
[  401.789873]  [<c0178cff>] vfs_read+0x89/0x11d
[  401.794266]  [<c0179164>] sys_read+0x3d/0x64
[  401.798569]  [<c01041ba>] syscall_call+0x7/0xb
[  401.803039]  =======================