Btrfs: avoid setting ->d_op twice

Follow those instructions, and you'll trigger a warning in the
beginning of d_set_d_op():

  # mkfs.btrfs /dev/loop3
  # mount /dev/loop3 /mnt
  # btrfs sub create /mnt/sub
  # btrfs sub snap /mnt /mnt/snap
  # touch /mnt/snap/sub
  touch: cannot touch `tmp': Permission denied

__d_alloc() set d_op to sb->s_d_op (btrfs_dentry_operations), and
then simple_lookup() reset it to simple_dentry_operations, which
triggered the warning.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
btrfs: fix race in reada

When inserting into the radix tree returns EEXIST, get the existing
entry without giving up the spinlock in between.
There was a race for both the zones trees and the extent tree.

Signed-off-by: Arne Jansen <sensille@gmx.net>
btrfs: don't add both copies of DUP to reada extent tree

Normally when there are 2 copies of a block, we add both to the
reada extent tree and prefetch only the one that is easier to reach.
This way we can better utilize multiple devices.
In case of DUP this makes no sense as both copies reside on the
same device.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Btrfs: do not mount when we have a sectorsize unequal to PAGE_SIZE

Our code is not ready to cope with a sectorsize that's not equal to PAGE_SIZE.
It will lead to hanging-on while writing something.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
btrfs: add missing unlocks to transaction abort paths

Added in commit 49b25e0540904be0bf558b84475c69d72e4de66e
("btrfs: enhance transaction abort infrastructure")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Btrfs: retrurn void from clear_state_bit

Currently it returns a set of bits that were cleared, but this return
value is not used at all.

Moreover it doesn't seem to be useful, because we may clear the bits
of a few extent_states, but only the cleared bits of last one is
returned.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Btrfs: avoid possible use-after-free in clear_extent_bit()

clear_extent_bit()
{
    next_node = rb_next(&state->rb_node);
    ...
    clear_state_bit(state);  <-- this may free next_node
    if (next_node) {
        state = rb_entry(next_node);
        ...
    }
}

clear_state_bit() calls merge_state() which may free the next node
of the passing extent_state, so clear_extent_bit() may end up
referencing freed memory.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Btrfs: Make free_ipath() deal gracefully with NULL pointers

Make free_ipath() behave like most other freeing functions in the
kernel and gracefully do nothing when passed a NULL pointer.

Besides this making the bahaviour consistent with functions such as
kfree(), vfree(), btrfs_free_path() etc etc, it also fixes a real NULL
deref issue in fs/btrfs/ioctl.c::btrfs_ioctl_ino_to_path(). In that
function we have this code:

...
        ipath = init_ipath(size, root, path);
        if (IS_ERR(ipath)) {
                ret = PTR_ERR(ipath);
                ipath = NULL;
                goto out;
        }
...
out:
        btrfs_free_path(path);
        free_ipath(ipath);
...

If we ever take the true branch of that 'if' statement we'll end up
passing a NULL pointer to free_ipath() which will subsequently
dereference it and we'll go "Boom" :-(
This patch will avoid that.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Btrfs: don't call free_extent_buffer twice in iterate_irefs

Avoid calling free_extent_buffer more than once when the iterator function
returns non-zero. The only code that uses this is scrub repair for corrupted
nodatasum blocks.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Btrfs: add missing read locks in backref.c

iref_to_path and iterate_irefs both increment the eb's refcount to use it
after releasing the path. Both depend on consistent data remaining in the
extent buffer and need a read lock to protect it.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Btrfs: fix max chunk size check in chunk allocator

Fix a bug, where in case we need to adjust stripe_size so that the
length of the resulting chunk is less than or equal to max_chunk_size,
DUP chunks turn out to be only half as big as they could be.

Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
btrfs: fix early abort in 'remount'

Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Josef Bacik <josef@redhat.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
fs/btrfs/volumes.c: add missing free_fs_devices

Free fs_devices as done in the error-handling code just below.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Btrfs: always store the mirror we read the eb from

A user reported a panic where we were trying to fix a bad mirror but the
mirror number we were giving was 0, which is invalid.  This is because we
don't do the transid verification until after the read, so as far as the
read code is concerned the read was a success.  So instead store the mirror
we read from so that if there is some failure post read we know which mirror
to try next and which mirror needs to be fixed if we find a good copy of the
block.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Btrfs: double unlock bug in error handling

The caller expects this function to return with the lock held and
releases it immediately on error.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
btrfs: don't return EINTR

It is basically a good thing if we are interruptible when waiting for
free space, but the generality in which it is implemented currently
leads to system calls being interruptible that are not documented this
way. For example git can't handle interrupted unlink(), leading to
corrupt repos under space pressure.
Instead we raise the bar to only be interruptible by SIGKILL.
Thanks to David Sterba for suggesting this.

Signed-off-by: Arne Jansen <sensille@gmx.net>
Btrfs: fix btrfs_ioctl_dev_info() crash on missing device

When a filesystem is mounted with the degraded option, it is
possible that some of the devices are not there.
btrfs_ioctl_dev_info() crashs in this case because the device
name is a NULL pointer. This ioctl was only used for scrub.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs: don't count CRC or header errors twice while scrubbing

Each CRC or header error was counted twice, this is now fixed.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Btrfs: fix that check_int_data mount option was ignored

The bitfield member mount_opt was too small by one bit to hold the mount
option that enabled to include data extents in the integrity checker.
Since the same issue happened when the BTRFS_MOUNT_PANIC_ON_FATAL_ERROR
option was added (git rebase silently merges so that the increase of the
size of the bitfield member is lost), the bit limit was removed entirely.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
ARM: ux300: Fix unimplementable regulation constraints

It doesn't make sense to grant permission to change the status of a
regulator that is also set as always on and similarly it doesn't make
sense to allow a driver to change the voltage of a regulator which can
only be set to a single voltage.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>