This is one more step on the way to "removable" UBI devices. It
adds reference counting for UBI devices. Every time a volume on
this device is opened - the device's refcount is increased. It
is also increased if someone is reading any sysfs file of this
UBI device or of one of its volumes.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch is a preparation to make UBI devices dynamic. It
adds an UBI control device which has dynamically allocated
major number and registers itself as "ubi_ctrl". It does not
do anything so far. The idea is that this device will allow
to attach/detach MTD devices from userspace.
This is symilar to what the Linux device mapper has.
The next things to do are:
* Fix UBI, because it now assumes UBI devices cannot go away
* Implement control device ioctls which will attach/detach MTD
devices
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The flush function should finish all the pending jobs. But if
somebody else is doing a work, this function should wait and let
it finish.
This patche uses rw semaphore for synchronization purpose - it
just looks quite convinient.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When the WL worker is moving an LEB, the volume might go away
occasionally. UBI does not handle these situations correctly.
This patch introduces a new mutex which serializes wear-levelling
worker and the the 'ubi_wl_put_peb()' function. Now, if one puts
an LEB, and its PEB is being moved, it will wait on the mutex.
And because we unmap all LEBs when removing volumes, this will make
the volume remove function to wait while the LEB movement
finishes.
Below is an example of an oops which should be fixed by this patch:
Pid: 9167, comm: io_paral Not tainted (2.6.24-rc5-ubi-2.6.git #2)
EIP: 0060:[<f884a379>] EFLAGS: 00010246 CPU: 0
EIP is at prot_tree_del+0x2a/0x63 [ubi]
EAX: f39a90e0 EBX: 00000000 ECX: 00000000 EDX: 00000134
ESI: f39a90e0 EDI: f39a90e0 EBP: f2d55ddc ESP: f2d55dd4
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process io_paral (pid: 9167, ti=f2d54000 task=f72a8030 task.ti=f2d54000)
Stack: f39a95f8 ef6aae50 f2d55e08 f884a511 f88538e1 f884ecea 00000134 00000000
f39a9604 f39a95f0 efea8280 00000000 f39a90e0 f2d55e40 f8847261 f8850c3c
f884eaad 00000001 000000b9 00000134 00000172 000000b9 00000134 00000001
Call Trace:
[<c0105227>] show_trace_log_lvl+0x1a/0x30
[<c01052e2>] show_stack_log_lvl+0xa5/0xca
[<c01053d6>] show_registers+0xcf/0x21b
[<c0105648>] die+0x126/0x224
[<c0119a62>] do_page_fault+0x27f/0x60d
[<c037dd62>] error_code+0x72/0x78
[<f884a511>] ubi_wl_put_peb+0xf0/0x191 [ubi]
[<f8847261>] ubi_eba_unmap_leb+0xaf/0xcc [ubi]
[<f8843c21>] ubi_remove_volume+0x102/0x1e8 [ubi]
[<f8846077>] ubi_cdev_ioctl+0x22a/0x383 [ubi]
[<c017d768>] do_ioctl+0x68/0x71
[<c017d7c6>] vfs_ioctl+0x55/0x271
[<c017da15>] sys_ioctl+0x33/0x52
[<c0104152>] sysenter_past_esp+0x5f/0xa5
=======================
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Make the code more consistent by requiring the caller to lock the
ubi->volume_mutex, because this is what we do for updates.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Add ref_count field to UBI volumes and remove weired "vol->removed"
field. This way things are better understandable and we do not have
to do whold show_attr operation under spinlock.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
If we fail halfway through sysfs file creation, we may just call
sysfs remove function and it will delete all the files we created.
For non-existing files it will also be OK - the remove functions
just return -ENOENT.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes error codes of the functions - if the device number
is out of range, -EINVAL should be returned. It also removes unneeded
try_module_get call from the open by name function.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Error path in volume creation is bogus. First of, it ovverrides the
'err' variable and returns zero to the caller. Second, ubi_assert()
in the release function is wrong.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When a volume is opened, get its kref via get_device() call.
And put the reference when closing the volume. With this, we
may have a bit saner volume delete.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Pass volume description object to the EBA function which makes
more sense, and EBA function do not have to find the volume
description object by volume ID.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Similarly to ltree_entry_slab, it makes more sense to create
and destroy ubi_wl_entry slab on module initialization/exit.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Since the ltree_entry slab cache is a global entity, which is
used by all UBI devices, it is more logical to create it on
module initialization time and destro on module exit time.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch silences the following warning :
drivers/mtd/ubi/vmt.c:73: warning: 'ret' may be used uninitialized in this function
gcc can't see that we always initialize ret in all situations where it is
actually used. The one case where it's not initialized is when we BUG(),
but gcc doesn't know that we won't then continue and use an uninitialized
'ret'.
This patch results in code that does exactely the same as before, but it
also makes gcc shut up, so we generate one less line of warning noise.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The idea of this interface belongs to Adrian Hunter. The
interface is extremely useful when one has to have a guarantee
that an LEB will contain all 0xFFs even in case of an unclean
reboot. UBI does have an 'ubi_leb_erase()' call which may do
this, but it is stupid and ineffecient, because it flushes whole
queue. I should be re-worked to just be a pair of unmap,
map calls.
The user of the interfaci is UBIFS at the moment.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
First allocate the necessary eraseblocks, then the optional ones.
Otherwise it allocates all PEBs for bad EB handling, and fails
on then following EBA LEB allocation.
Reported-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When NAND detects an ECC error, it returns -EBADMSG. It does not
stop reading requested data if one page has an ECC error, it keeps
going and reads all the requested data. If it fails to read all
the data, it does not return -EBADMSG, but returns the error code
which reflects the reason of the failure.
But some drivers may have bugs (e.g., OneNAND had) and stop reading
after the first ECC error, so it returns -EBADMSG. In turn, UBI
propagates this up to the caller. The caller will treat this as
"all the requested data was read, but there was an ECC error".
So we change the error code to -EIO if it is -EBADMSG and the read
length is less then the requested length. We also add an assertion,
so if UBI debugging is enabled, UBI will bug.
Pointed-to-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.
The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.
[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Slab constructors currently have a flags parameter that is never used. And
the order of the arguments is opposite to other slab functions. The object
pointer is placed before the kmem_cache pointer.
Convert
ctor(void *object, struct kmem_cache *s, unsigned long flags)
to
ctor(struct kmem_cache *s, void *object)
throughout the kernel
[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following warning:
drivers/mtd/ubi/eba.c: In function 'ubi_eba_init_scan':
drivers/mtd/ubi/eba.c:1116: warning: 'err' may be used uninitialized in this function
Pointed-to-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When the UBI device is nearly full, i.e. all LEBs are mapped, we have
only one spare LEB left - the one we reserved for WL purposes. Well,
I do not count the LEBs which were reserved for bad PEB handling -
suppose NOR flash for simplicity. If an "atomic LEB change operation"
is run, and the WL unit is moving a LEB, we have no spare LEBs to
finish the operation and fail, which is not good. Moreover, if there
are 2 or more simultanious "atomic LEB change" requests, only one of
them has chances to succeed, the other will fail with -ENOSPC. Not
good either.
This patch does 2 things:
1. Reserves one PEB for the "atomic LEB change" operation.
2. Serealize the operations so that only on of them may run
at a time (by means of a mutex).
Pointed-to-by: Brijesh Singh <brijesh.s.singh@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Similar reason as in case of the previous patch: it causes
deadlocks if a filesystem with writeback support works on top
of UBI. So pre-allocate needed buffers when attaching MTD device.
We also need mutexes to protect the buffers, but they do not
cause much contantion because they are used in recovery, torture,
and WL copy routines, which are called seldom.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Use GFP_NOFS flag when allocating memory on I/O path, because otherwise
we may deadlock the filesystem which works on top of us. We observed
the deadlocks with UBIFS. Example:
VFS->FS lock a lock->UBI->kmalloc()->VFS writeback->FS locks the same
lock again.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
I can't find anything guaranteeing that 'ubi_num' cannot be <0 in
drivers/mtd/ubi/kapi.c::ubi_open_volume(), and in fact the code
even tests for that and errors out if so. Unfortunately the test
for "ubi_num < 0" happens after we've already used 'ubi_num' as
an array index - bad thing to do if it is negative.
This patch moves the test earlier in the function and then moves
the indexing using that variable after the check. A bit safer :-)
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
I hit those situations and found out lack of print messages. Add more prints
when erase problems occur.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Fix "symbol shadows an earlier one" warnings. Although they are harmless
but it does not hurt to fix them and make sparse happy.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Coverity (1769) found the following problem: if the erase counter
overflow check triggers, ec_hdr is leaked.
Moving the allocation after the overflow check should take care of it.
Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
To be able to convert kmalloc + memset(..., 1, ...) to kzalloc this patch
reverses the logic around 'buf'.
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
cdev.c whines in current git:
drivers/mtd/ubi/cdev.c: In function `major_to_device':
drivers/mtd/ubi/cdev.c:67: warning: control reaches end of non-void function
Shut it up.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Do not switch to read-only mode in case of -EINTR and some
other obvious cases. Switch to RO mode only when we do not
know what is the error.
Reported-by: Vinit Agnihotri <vinit.agnihotri@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The use of try_module_get(THIS_MODULE) in ubi_get_device_info does not
offer real protection against unexpected driver unloads, since we could
be preempted before try_modules_get gets executed. It is the caller who
should manipulate the refcounts. Besides, ubi_get_device_info is an
exported symbol which guarantees protection when accessed through
symbol_get.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
I was experiencing overflows in multiplications for
volume->used_bytes in vmt.c & vtbl.c, while creating & resizing large volumes.
vol->used_bytes is long long however its 2 operands vol->used_ebs &
vol->usable_leb_size
are int. So their multiplication for larger values causes integer overflows.
Typecasting them solves the problem.
My machine & flash details:
64Bit dual-core AMD opteron, 1 GB RAM, linux 2.6.18.3.
mtd size = 6GB, volume size= 5GB, peb_size = 4MB.
heres patch which does the fix.
Signed-off-by: Vinit Agnihotri <vinit.agnihotri@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
