* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep: Check the depth of subclass
lockdep: Add improved subclass caching
affs: Use sema_init instead of init_MUTEX
hfs: Convert tree_lock to mutex
arm: Bcmring: semaphore cleanup
printk: Make console_sem a semaphore not a pseudo mutex
drivers/macintosh/adb: Do not claim that the semaphore is a mutex
parport: Semaphore cleanup
irda: Semaphore cleanup
net: Wan/cosa.c: Convert "mutex" to semaphore
net: Ppp_async: semaphore cleanup
hamradio: Mkiss: semaphore cleanup
hamradio: 6pack: semaphore cleanup
net: 3c527: semaphore cleanup
input: Serio/hp_sdc: semaphore cleanup
input: Serio/hil_mlc: semaphore cleanup
input: Misc/hp_sdc_rtc: semaphore cleanup
lockup_detector: Make callback function static
lockup detector: Fix grammar by adding a missing "to" in the comments
lockdep: Remove __debug_show_held_locks
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86/amd-iommu: Update copyright headers
x86/amd-iommu: Reenable AMD IOMMU if it's mysteriously vanished over suspend
AGP: Warn when GATT memory cannot be set to UC
x86, GART: Disable GART table walk probes
x86, GART: Remove superfluous AMD64_GARTEN
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (26 commits)
selinux: include vmalloc.h for vmalloc_user
secmark: fix config problem when CONFIG_NF_CONNTRACK_SECMARK is not set
selinux: implement mmap on /selinux/policy
SELinux: allow userspace to read policy back out of the kernel
SELinux: drop useless (and incorrect) AVTAB_MAX_SIZE
SELinux: deterministic ordering of range transition rules
kernel: roundup should only reference arguments once
kernel: rounddown helper function
secmark: export secctx, drop secmark in procfs
conntrack: export lsm context rather than internal secid via netlink
security: secid_to_secctx returns len when data is NULL
secmark: make secmark object handling generic
secmark: do not return early if there was no error
AppArmor: Ensure the size of the copy is < the buffer allocated to hold it
TOMOYO: Print URL information before panic().
security: remove unused parameter from security_task_setscheduler()
tpm: change 'tpm_suspend_pcr' to be module parameter
selinux: fix up style problem on /selinux/status
selinux: change to new flag variable
selinux: really fix dependency causing parallel compile failure.
...
* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
virtio_blk: remove BKL leftovers
virtio: console: Disable lseek(2) for port file operations
virtio: console: Send SIGIO in case of port unplug
virtio: console: Send SIGIO on new data arrival on ports
virtio: console: Send SIGIO to processes that request it for host events
virtio: console: Reference counting portdev structs is not needed
virtio: console: Add reference counting for port struct
virtio: console: Use cdev_alloc() instead of cdev_init()
virtio: console: Add a find_port_by_devt() function
virtio: console: Add a list of portdevs that are active
virtio: console: open: Use a common path for error handling
virtio: console: remove_port() should return void
virtio: console: Make write() return -ENODEV on hot-unplug
virtio: console: Make read() return -ENODEV on hot-unplug
virtio: console: Unblock poll on port hot-unplug
virtio: console: Un-block reads on chardev close
virtio: console: Check if portdev is valid in send_control_msg()
virtio: console: Remove control vq data only if using multiport support
virtio: console: Reset vdev before removing device
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (22 commits)
ceph: do not carry i_lock for readdir from dcache
fs/ceph/xattr.c: Use kmemdup
rbd: passing wrong variable to bvec_kunmap_irq()
rbd: null vs ERR_PTR
ceph: fix num_pages_free accounting in pagelist
ceph: add CEPH_MDS_OP_SETDIRLAYOUT and associated ioctl.
ceph: don't crash when passed bad mount options
ceph: fix debugfs warnings
block: rbd: removing unnecessary test
block: rbd: fixed may leaks
ceph: switch from BKL to lock_flocks()
ceph: preallocate flock state without locks held
ceph: add pagelist_reserve, pagelist_truncate, pagelist_set_cursor
ceph: use mapping->nrpages to determine if mapping is empty
ceph: only invalidate on check_caps if we actually have pages
ceph: do not hide .snap in root directory
rbd: introduce rados block device (rbd), based on libceph
ceph: factor out libceph from Ceph file system
ceph-rbd: osdc support for osd call and rollback operations
ceph: messenger and osdc changes for rbd
...
Remove the BKL usage added in "block: push down BKL into .locked_ioctl".
Virtio-blk doesn't use the BKL for anything, and doesn't implement any
ioctl command by itself, but only uses the generic scsi_cmd_ioctl
which is fine without the BKL.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The ports are char devices; do not have seeking capabilities. Calling
nonseekable_open() from the fops_open() call and setting the llseek fops
pointer to no_llseek ensures an lseek() call from userspace returns
-ESPIPE.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a port has registered for SIGIO signals, let the application
know that the port is getting unplugged.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Send a SIGIO signal when new data arrives on a port. This is sent only
when the process has requested for the signal to be sent using fcntl().
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A process can request for SIGIO on host connect / disconnect events
using the O_ASYNC file flag using fcntl().
If that's requested, and if the guest-side connection for the port is
open, any host-side open/close events for that port will raise a SIGIO.
The process can then use poll() within the signal handler to find out
which port triggered the signal.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Explain in a comment why there's no need to reference-count the portdev
struct: when a device is yanked out, we can't do anything more with it
anyway so just give up doing anything more with the data or the vqs and
exit cleanly.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port got hot-unplugged, when a port was open, any file operation
after the unplugging resulted in a crash. This is fixed by ref-counting
the port structure, and releasing it only when the file is closed.
This splits the unplug operation in two parts: first marks the port
as unavailable, removes all the buffers in the vqs and removes the port
from the per-device list of ports. The second stage, invoked when all
references drop to zero, releases the chardev and frees all other memory.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This moves to using cdev on the heap instead of it being embedded in the
ports struct. This helps individual refcounting and will allow us to
properly remove cdev structs after hot-unplugs and close operations.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
To convert to using cdev as a pointer to avoid kref troubles, we have to
use a different method to get to a port from an inode than the current
container_of method.
Add find_port_by_devt() that looks up all portdevs and ports with those
portdevs to find the right port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtio_console.c driver is capable of handling multiple devices at a
time. Maintain a list of devices for future traversal.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is removed, we have to assume the port is gone. So a
success/failure return value doesn't make sense.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app was blocked on a write() call,
the call was unblocked but would not get an error returned.
Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app was blocked on a read() call,
the call was unblocked but would not get an error returned.
Return -ENODEV to ensure the app knows the port has gone away.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When a port is hot-unplugged while an app is blocked on poll(), unblock
the poll() and return.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a chardev is closed, any blocked read / poll calls should just return
and not attempt to use other state.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A portdev may have been hot-unplugged while a port was open()ed. Skip
sending control messages when the portdev isn't valid.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If a portdev isn't using multiport support, it won't have any control vq
data to remove.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtqueues should be disabled before attempting to remove the
device.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
