Marcel, This patch series addresses a number of previously unknown issues with the RFCOMM tty device implementation, in addition to addressing the locking regression recently reported [1]. As Gianluca suggested and I agree, this series first reverts 3 of the 4 patches of 3.14-rc1 for bluetooth/rfcomm/tty.c. The reasoning is detailed in the changelog for Revert "Bluetooth: Always wait for a connection on RFCOMM open()" but the short answer is that it re-implements a long-standing bug by blocking on a non-blocking open. This patch series corrects the reported regressions from 3.13 (to the extent that correction is required). Specifically, the ModemManager regression reported by Gianluca Anzolin [2] and the rfcomm bind with wvdial reported by Andrey Vihrov [3]. tty: Fix ref counting for port krefs Bluetooth: Fix racy acquire of rfcomm_dev reference Bluetooth: Exclude released devices from RFCOMMGETDEVLIST ioctl Bluetooth: Release rfcomm_dev only once Bluetooth: Fix unreleased rfcomm_dev reference These first 5 patches after the reverts fix 4 different rfcomm_dev ref count mishandling bugs. Bluetooth: Fix RFCOMM tty teardown race and Bluetooth: Serialize RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls Fix races which occur due to the design of the rfcomm ioctls (note that buses don't have these kinds of races). Bluetooth: Verify dlci not in use before rfcomm_dev create Bluetooth: Simplify RFCOMM session state eval Bluetooth: Refactor deferred setup test in rfcomm_dlc_close() Bluetooth: Refactor dlc disconnect logic in rfcomm_dlc_close() Bluetooth: Directly close dlc for not yet started RFCOMM session These 5 patches fix issues with reusing the dlci after closing the tty (found by unit test). Bluetooth: Fix unsafe RFCOMM device parenting Bluetooth: Fix RFCOMM parent device for reused dlc These 2 patches fix the ModemManager regression. Bluetooth: Refactor rfcomm_dev_add() Bluetooth: Cleanup RFCOMM device registration error handling These 2 patches fix an unreleased module reference while error handling. Bluetooth: Rename __rfcomm_dev_get() to __rfcomm_dev_lookup() This is a trivial naming patch with no functional impact. Bluetooth: Force -EIO from tty read/write if .activate() fails The tty core provides an existing mechanism for failing reads/writes if device activation fails (like an error allocating the dlc). Bluetooth: Don't fail RFCOMM tty writes This patch implements buffered writes even if the device is not connected. While unit testing this, I discovered a serious defect in the way available space is computed that under-utilizes rfcomm i/o and may even halt further tx on that link, which is fixed by: Bluetooth: Refactor write_room() calculation Bluetooth: Fix write_room() calculation Note that this series does not fix the naively inefficient method of packetizing tty output; packetizing should be done on the krfcommd thread to take advantage of aggregating multiple tty writes into 1 or more packets. Look at any line-by-line console output to realize how under-utilized the rfcomm tty packeting is. [1] http://www.spinics.net/lists/linux-wireless/msg117818.html [2] http://www.spinics.net/lists/linux-bluetooth/msg42075.html [3] http://www.spinics.net/lists/linux-bluetooth/msg42057.html Regards, Peter Hurley (24): Revert "Bluetooth: Remove rfcomm_carrier_raised()" Revert "Bluetooth: Always wait for a connection on RFCOMM open()" Revert "Bluetooth: Move rfcomm_get_device() before rfcomm_dev_activate()" tty: Fix ref counting for port krefs Bluetooth: Fix racy acquire of rfcomm_dev reference Bluetooth: Exclude released devices from RFCOMMGETDEVLIST ioctl Bluetooth: Release rfcomm_dev only once Bluetooth: Fix unreleased rfcomm_dev reference Bluetooth: Fix RFCOMM tty teardown race Bluetooth: Verify dlci not in use before rfcomm_dev create Bluetooth: Simplify RFCOMM session state eval Bluetooth: Refactor deferred setup test in rfcomm_dlc_close() Bluetooth: Refactor dlc disconnect logic in rfcomm_dlc_close() Bluetooth: Directly close dlc for not yet started RFCOMM session Bluetooth: Fix unsafe RFCOMM device parenting Bluetooth: Fix RFCOMM parent device for reused dlc Bluetooth: Rename __rfcomm_dev_get() to __rfcomm_dev_lookup() Bluetooth: Serialize RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls Bluetooth: Refactor rfcomm_dev_add() Bluetooth: Cleanup RFCOMM device registration error handling Bluetooth: Force -EIO from tty read/write if .activate() fails Bluetooth: Don't fail RFCOMM tty writes Bluetooth: Refactor write_room() calculation Bluetooth: Fix write_room() calculation include/linux/tty.h | 6 +- include/net/bluetooth/rfcomm.h | 9 +- net/bluetooth/rfcomm/core.c | 88 ++++++++++---- net/bluetooth/rfcomm/tty.c | 262 ++++++++++++++++++++++------------------- 4 files changed, 223 insertions(+), 142 deletions(-) -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
