diff options
| author | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2008-08-05 18:16:59 +0200 |
|---|---|---|
| committer | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2008-08-05 18:16:59 +0200 |
| commit | d3e33ff59facec005e48ba3360502b73a04e4b4e (patch) | |
| tree | 7f5b6354d5d6794b35a5ea2bcee33ea16d8e326c /drivers/scsi | |
| parent | b5b9309d3415480b3e66314a1d6c89db58bff9de (diff) | |
ide: fix regression caused by ide_device_{get,put}() addition (take 2)
On Monday 28 July 2008, Benjamin Herrenschmidt wrote:
[...]
> Vector: 300 (Data Access) at [c58b7b80]
> pc: c014f264: elv_may_queue+0x10/0x44
> lr: c0152750: get_request+0x2c/0x2c0
> sp: c58b7c30
> msr: 1032
> dar: c
> dsisr: 40000000
> current = 0xc58aaae0
> pid = 854, comm = media-bay
> enter ? for help
> mon> t
> [c58b7c40] c0152750 get_request+0x2c/0x2c0
> [c58b7c70] c0152a08 get_request_wait+0x24/0xec
> [c58b7cc0] c0225674 ide_cd_queue_pc+0x58/0x1a0
> [c58b7d40] c022672c ide_cdrom_packet+0x9c/0xdc
> [c58b7d70] c0261810 cdrom_get_disc_info+0x60/0xd0
> [c58b7dc0] c026208c cdrom_mrw_exit+0x1c/0x11c
> [c58b7e30] c0260f7c unregister_cdrom+0x84/0xe8
> [c58b7e50] c022395c ide_cd_release+0x80/0x84
> [c58b7e70] c0163650 kref_put+0x54/0x6c
> [c58b7e80] c0223884 ide_cd_put+0x40/0x5c
> [c58b7ea0] c0211100 generic_ide_remove+0x28/0x3c
> [c58b7eb0] c01e9d34 __device_release_driver+0x78/0xb4
> [c58b7ec0] c01e9e44 device_release_driver+0x28/0x44
> [c58b7ee0] c01e8f7c bus_remove_device+0xac/0xd8
> [c58b7f00] c01e7424 device_del+0x104/0x198
> [c58b7f20] c01e74d0 device_unregister+0x18/0x30
> [c58b7f40] c02121c4 __ide_port_unregister_devices+0x6c/0x88
> [c58b7f60] c0212398 ide_port_unregister_devices+0x38/0x80
> [c58b7f80] c0208ca4 media_bay_step+0x1cc/0x5c0
> [c58b7fb0] c0209124 media_bay_task+0x8c/0xcc
> [c58b7fd0] c00485c0 kthread+0x48/0x84
> [c58b7ff0] c0011b20 kernel_thread+0x44/0x60
The guilty commit turned out to be 08da591e14cf87247ec09b17c350235157a92fc3
("ide: add ide_device_{get,put}() helpers"). ide_device_put() is called
before kref_put() in ide_cd_put() so IDE device is already gone by the time
ide_cd_release() is reached.
Fix it by calling ide_device_get() before kref_get() and ide_device_put()
after kref_put() in all affected device drivers.
v2:
Brown paper bag time. In v1 cd->drive was referenced after dropping last
reference on cd object (which could result in OOPS in ide_device_put() as
reported/debugged by Mariusz Kozlowski). Fix it by caching cd->drive in
the local variable (fix other device drivers too).
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Tested-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/ide-scsi.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c index b40a673985aa..461331d3dc45 100644 --- a/drivers/scsi/ide-scsi.c +++ b/drivers/scsi/ide-scsi.c @@ -102,11 +102,10 @@ static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk) mutex_lock(&idescsi_ref_mutex); scsi = ide_scsi_g(disk); if (scsi) { - scsi_host_get(scsi->host); - if (ide_device_get(scsi->drive)) { - scsi_host_put(scsi->host); + if (ide_device_get(scsi->drive)) scsi = NULL; - } + else + scsi_host_get(scsi->host); } mutex_unlock(&idescsi_ref_mutex); return scsi; @@ -114,9 +113,11 @@ static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk) static void ide_scsi_put(struct ide_scsi_obj *scsi) { + ide_drive_t *drive = scsi->drive; + mutex_lock(&idescsi_ref_mutex); - ide_device_put(scsi->drive); scsi_host_put(scsi->host); + ide_device_put(drive); mutex_unlock(&idescsi_ref_mutex); } |