* 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits)
virtio-blk: use ida to allocate disk index
hpsa: add small delay when using PCI Power Management to reset for kump
cciss: add small delay when using PCI Power Management to reset for kump
xen/blkback: Fix two races in the handling of barrier requests.
xen/blkback: Check for proper operation.
xen/blkback: Fix the inhibition to map pages when discarding sector ranges.
xen/blkback: Report VBD_WSECT (wr_sect) properly.
xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests.
xen-blkfront: plug device number leak in xlblk_init() error path
xen-blkfront: If no barrier or flush is supported, use invalid operation.
xen-blkback: use kzalloc() in favor of kmalloc()+memset()
xen-blkback: fixed indentation and comments
xen-blkfront: fix a deadlock while handling discard response
xen-blkfront: Handle discard requests.
xen-blkback: Implement discard requests ('feature-discard')
xen-blkfront: add BLKIF_OP_DISCARD and discard request struct
drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd()
drivers/block/loop.c: emit uevent on auto release
drivers/block/cpqarray.c: use pci_dev->revision
loop: always allow userspace partitions and optionally support automatic scanning
...
Fic up trivial header file includsion conflict in drivers/block/loop.c
Currently the loop device tries to call directly into write_begin/write_end
instead of going through ->write if it can. This is a fairly nasty shortcut
as write_begin and write_end are only callbacks for the generic write code
and expect to be called with filesystem specific locks held.
This code currently causes various issues for clustered filesystems as it
doesn't take the required cluster locks, and it also causes issues for XFS
as it doesn't properly lock against the swapext ioctl as called by the
defragmentation tools. This in case causes data corruption if
defragmentation hits a busy loop device in the wrong time window, as
reported by RH QA.
The reason why we have this shortcut is that it saves a data copy when
doing a transformation on the loop device, which is the technical term
for using cryptoloop (or an XOR transformation). Given that cryptoloop
has been deprecated in favour of dm-crypt my opinion is that we should
simply drop this shortcut instead of finding complicated ways to to
introduce a formal interface for this shortcut.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If the loop device is associated (lo->lo_state == Lo_bound), it will have
a valid bdev pointed to by lo->lo_device. There is no reason to ever pass
an additional block_device pointer.
Signed-off-by: Ayan George <ayan.george@canonical.com>
Cc: Phillip Susi <psusi@cfl.rr.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The loopback driver failed to emit the change uevent when auto releasing
the device. Fixed lo_release() to pass the bdev to loop_clr_fd() so it
can emit the event.
Signed-off-by: Phillip Susi <psusi@cfl.rr.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ayan George <ayan@ayan.net>
Signed-off-by: Andrew Morton <akpm@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.
Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Automatic partition scanning can be requested individually per loop
device during its setup by setting LO_FLAGS_PARTSCAN. By default, no
partition tables are scanned.
Userspace can now always add and remove partitions from all loop
devices, regardless if the in-kernel partition scanner is enabled or
not.
The needed partition minor numbers are allocated from the extended
minors space, the main loop device numbers will continue to match the
loop minors, regardless of the number of partitions used.
# grep . /sys/class/block/loop1/loop/*
/sys/block/loop1/loop/autoclear:0
/sys/block/loop1/loop/backing_file:/home/kay/data/stuff/part.img
/sys/block/loop1/loop/offset:0
/sys/block/loop1/loop/partscan:1
/sys/block/loop1/loop/sizelimit:0
# ls -l /dev/loop*
brw-rw---- 1 root disk 7, 0 Aug 14 20:22 /dev/loop0
brw-rw---- 1 root disk 7, 1 Aug 14 20:23 /dev/loop1
brw-rw---- 1 root disk 259, 0 Aug 14 20:23 /dev/loop1p1
brw-rw---- 1 root disk 259, 1 Aug 14 20:23 /dev/loop1p2
brw-rw---- 1 root disk 7, 99 Aug 14 20:23 /dev/loop99
brw-rw---- 1 root disk 259, 2 Aug 14 20:23 /dev/loop99p1
brw-rw---- 1 root disk 259, 3 Aug 14 20:23 /dev/loop99p2
crw------T 1 root root 10, 237 Aug 14 20:22 /dev/loop-control
Cc: Karel Zak <kzak@redhat.com>
Cc: Davidlohr Bueso <dave@gnu.org>
Acked-By: Tejun Heo <tj@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit adds discard support for loop devices. Discard is usually
supported by SSD and thinly provisioned devices as a method for
reclaiming unused space. This is no different than trying to reclaim
back space which is not used by the file system on the image, but it
still occupies space on the host file system.
We can do the reclamation on file system which does support hole
punching. So when discard request gets to the loop driver we can
translate that to punch a hole to the underlying file, hence reclaim
the free space.
This is very useful for trimming down the size of the image to only what
is really used by the file system on that image. Fstrim may be used for
that purpose.
It has been tested on ext4, xfs and btrfs with the image file systems
ext4, ext3, xfs and btrfs. ext4, or ext6 image on ext4 file system has
some problems but it seems that ext4 punch hole implementation is
somewhat flawed and it is unrelated to this commit.
Also this is a very good method of validating file systems punch hole
implementation.
Note that when encryption is used, discard support is disabled, because
using it might leak some information useful for possible attacker.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
LOOP_CLR_FD takes lo->lo_ctl_mutex and tries to remove the loop sysfs
files. Sysfs calls show() and waits for lo->lo_ctl_mutex. LOOP_CLR_FD
waits for show() to finish to remove the sysfs file.
cat /sys/class/block/loop0/loop/backing_file
mutex_lock_nested+0x176/0x350
? loop_attr_do_show_backing_file+0x2f/0xd0 [loop]
? loop_attr_do_show_backing_file+0x2f/0xd0 [loop]
loop_attr_do_show_backing_file+0x2f/0xd0 [loop]
dev_attr_show+0x1b/0x60
? sysfs_read_file+0x86/0x1a0
? __get_free_pages+0x12/0x50
sysfs_read_file+0xaf/0x1a0
ioctl(LOOP_CLR_FD):
wait_for_common+0x12c/0x180
? try_to_wake_up+0x2a0/0x2a0
wait_for_completion+0x18/0x20
sysfs_deactivate+0x178/0x180
? sysfs_addrm_finish+0x43/0x70
? sysfs_addrm_start+0x1d/0x20
sysfs_addrm_finish+0x43/0x70
sysfs_hash_and_remove+0x85/0xa0
sysfs_remove_group+0x59/0x100
loop_clr_fd+0x1dc/0x3f0 [loop]
lo_ioctl+0x223/0x7a0 [loop]
Instead of taking the lo_ctl_mutex from sysfs code, take the inner
lo->lo_lock, to protect the access to the backing_file data.
Thanks to Tejun for help debugging and finding a solution.
Cc: Milan Broz <mbroz@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Instead of unconditionally creating a fixed number of dead loop
devices which need to be investigated by storage handling services,
even when they are never used, we allow distros start with 0
loop devices and have losetup(8) and similar switch to the dynamic
/dev/loop-control interface instead of searching /dev/loop%i for free
devices.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Loop devices today have a fixed pre-allocated number of usually 8.
The number can only be changed at module init time. To find a free
device to use, /dev/loop%i needs to be scanned, and all devices need
to be opened until a free one is possibly found.
This adds a new /dev/loop-control device node, that allows to
dynamically find or allocate a free device, and to add and remove loop
devices from the running system:
LOOP_CTL_ADD adds a specific device. Arg is the number
of the device. It returns the device i or a negative
error code.
LOOP_CTL_REMOVE removes a specific device, Arg is the
number the device. It returns the device i or a negative
error code.
LOOP_CTL_GET_FREE finds the next unbound device or allocates
a new one. No arg is given. It returns the device i or a
negative error code.
The loop kernel module gets automatically loaded when
/dev/loop-control is accessed the first time. The alias
specified in the module, instructs udev to create this
'dead' device node, even when the module is not loaded.
Example:
cfd = open("/dev/loop-control", O_RDWR);
# add a new specific loop device
err = ioctl(cfd, LOOP_CTL_ADD, devnr);
# remove a specific loop device
err = ioctl(cfd, LOOP_CTL_REMOVE, devnr);
# find or allocate a free loop device to use
devnr = ioctl(cfd, LOOP_CTL_GET_FREE);
sprintf(loopname, "/dev/loop%i", devnr);
ffd = open("backing-file", O_RDWR);
lfd = open(loopname, O_RDWR);
err = ioctl(lfd, LOOP_SET_FD, ffd);
Cc: Tejun Heo <tj@kernel.org>
Cc: Karel Zak <kzak@redhat.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Replace the linked list, that keeps track of allocated devices, with an
idr index to allow a more efficient lookup of devices.
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Export 'max_loop' and 'max_part' parameters to sysfs so user can know
that how many devices are allowed and how many partitions are supported.
If 'max_loop' is 0, there is no restriction on the number of loop devices.
User can create/use the devices as many as minor numbers available. If
'max_part' is 0, it means simply the device doesn't support partitioning.
Also note that 'max_part' can be adjusted to power of 2 minus 1 form if
needed. User should check this value after the module loading if he/she
want to use that number correctly (i.e. fdisk, mknod, etc.).
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
When finding or allocating a loop device, loop_probe() did not take
partition numbers into account so that it can result to a different
device. Consider following example:
$ sudo modprobe loop max_part=15
$ ls -l /dev/loop*
brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0
brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1
brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2
brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3
brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4
brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5
brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6
brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7
$ sudo mknod /dev/loop8 b 7 128
$ sudo losetup /dev/loop8 ~/temp/disk-with-3-parts.img
$ sudo losetup -a
/dev/loop128: [0805]:278201 (/home/namhyung/temp/disk-with-3-parts.img)
$ ls -l /dev/loop*
brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0
brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1
brw-rw---- 1 root disk 7, 2048 2011-05-24 22:18 /dev/loop128
brw-rw---- 1 root disk 7, 2049 2011-05-24 22:18 /dev/loop128p1
brw-rw---- 1 root disk 7, 2050 2011-05-24 22:18 /dev/loop128p2
brw-rw---- 1 root disk 7, 2051 2011-05-24 22:18 /dev/loop128p3
brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2
brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3
brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4
brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5
brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6
brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7
brw-r--r-- 1 root root 7, 128 2011-05-24 22:17 /dev/loop8
After this patch, /dev/loop8 - instead of /dev/loop128 - was
accessed correctly.
In addition, 'range' passed to blk_register_region() should
include all range of dev_t that LOOP_MAJOR can address. It does
not need to be limited by partition numbers unless 'max_loop'
param was specified.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This merge creates two set of conflicts. One is simple context
conflicts caused by removal of throtl_scheduled_delayed_work() in
for-linus and removal of throtl_shutdown_timer_wq() in
for-2.6.39/core.
The other is caused by commit 255bb490c8 (block: blk-flush shouldn't
call directly into q->request_fn() __blk_run_queue()) in for-linus
crashing with FLUSH reimplementation in for-2.6.39/core. The conflict
isn't trivial but the resolution is straight-forward.
* __blk_run_queue() calls in flush_end_io() and flush_data_end_io()
should be called with @force_kblockd set to %true.
* elv_insert() in blk_kick_flush() should use
%ELEVATOR_INSERT_REQUEUE.
Both changes are to avoid invoking ->request_fn() directly from
request completion path and closely match the changes in the commit
255bb490c8.
Signed-off-by: Tejun Heo <tj@kernel.org>
Now we initialize ->queue_lock at queue allocation time so driver does
not have to worry about initializing it before calling
blk_cleanup_queue().
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Performing
$ sudo mount -o loop -o umask=0 /dev/sdb1 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
$ sudo modprobe -r loop
results in oops:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
IP: [<ffffffff812479d4>] do_raw_spin_lock+0x14/0x122
Process modprobe (pid: 6189, threadinfo ffff88009a898000, task ffff880154a88000)
Call Trace:
[<ffffffff81486788>] _raw_spin_lock_irq+0x4a/0x51
[<ffffffff8123404b>] ? blk_throtl_exit+0x3b/0xa0
[<ffffffff8105b120>] ? cancel_delayed_work_sync+0xd/0xf
[<ffffffff8123404b>] blk_throtl_exit+0x3b/0xa0
[<ffffffff81229bc8>] blk_release_queue+0x21/0x65
[<ffffffff8123bb06>] kobject_release+0x51/0x66
[<ffffffff8123bab5>] ? kobject_release+0x0/0x66
[<ffffffff8123ce1e>] kref_put+0x43/0x4d
[<ffffffff8123ba27>] kobject_put+0x47/0x4b
[<ffffffff8122717c>] blk_cleanup_queue+0x56/0x5b
[<ffffffffa01c3824>] loop_exit+0x68/0x844 [loop]
[<ffffffff8107cccc>] sys_delete_module+0x1e8/0x25b
[<ffffffff814864c9>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff81002112>] system_call_fastpath+0x16/0x1b
because of an attempt to acquire NULL queue_lock.
I added the same lines as in blk_queue_make_request -
index 44e18c0..49e6a54 100644`fall back to embedded per-queue lock'.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Commit a8adbe3 forgot to remove the return variable, kill it.
drivers/block/loop.c: In function 'lo_splice_actor':
drivers/block/loop.c:398: warning: unused variable 'ret'
[...]
fs/nfsd/vfs.c: In function 'nfsd_splice_actor':
fs/nfsd/vfs.c:848: warning: unused variable 'ret'
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch pulls calls to buf->ops->confirm() from all actors passed
(also indirectly) to splice_from_pipe_feed().
Is avoiding the call to buf->ops->confirm() while splice()ing to
/dev/null is an intentional optimization? No other user does that
and this will remove this special case.
Against current linux.git 6313e3c217.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
REQ_HARDBARRIER is dead now, so remove the leftovers. What's left
at this point is:
- various checks inside the block layer.
- sanity checks in bio based drivers.
- now unused bio_empty_barrier helper.
- Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
but Xen really needs to sort out it's barrier situaton.
- setting of ordered tags in uas - dead code copied from old scsi
drivers.
- scsi different retry for barriers - it's dead and should have been
removed when flushes were converted to FS requests.
- blktrace handling of barriers - removed. Someone who knows blktrace
better should add support for REQ_FLUSH and REQ_FUA, though.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
