The data type of max_sectors in queue settings is unsigned int.  But
this value is stored to the local variable whose type is unsigned short
in bio_size_ok().  This can cause unexpected result when max_sectors >
0xffff.

Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Replace kmalloc(size * nr, ) with kmalloc_array(nr, size), thus making
it easier to check is that the calculation doesn't wrap or return a smaller allocation
Signed-off-by: NDulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: NZach Brown <zab@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Use WARN_ON()'s return value in place of WARN_ON(1) for cleaner source
code that outputs a more descriptive warnings. Also fix the styling
warning of redundant braces that came up as a result of this fix.
Signed-off-by: NDulshani Gunawardhana <dulshani.gunawardhana89@gmail.com>
Reviewed-by: NZach Brown <zab@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

fs/btrfs/compat.h only contained trivial macro wrappers of drop_nlink()
and inc_nlink().  This doesn't belong in mainline.
Signed-off-by: NZach Brown <zab@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Device stats are only initialized (read from tree items) on mount.
Trying to read device stats after adding or replacing new devices will
return errors.

btrfs_init_new_device() and btrfs_init_dev_replace_tgtdev() are the two
functions that allocate and initialize new btrfs_device structures after
a filesystem is mounted. They set the device stats to zero by using
kzalloc() which is correct for new devices. The only missing thing was
to declare these stats as being valid (device->dev_stats_valid = 1) and
this patch adds this missing code.

This is the reproducer:

TEST_DEV1=/dev/sdzzzzz1
TEST_DEV2=/dev/sdzzzzz2
TEST_DEV3=/dev/sdzzzzz3
TEST_MNT=/mnt
mkfs.btrfs $TEST_DEV1
mount $TEST_DEV1 $TEST_MNT
btrfs device add $TEST_DEV2 $TEST_MNT
btrfs device stat $TEST_MNT
btrfs replace start -B $TEST_DEV2 $TEST_DEV3 $TEST_MNT
btrfs device stat $TEST_MNT
umount $TEST_MNT
Reported-by: NOndrej Kunc <kunc88@gmail.com>
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

For both balance and replace, cancelling involves changing the on-disk
state and committing a transaction, which is not a good thing to do on
read-only filesystems.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

On mount failures, __btrfs_close_devices can be called well before
dev-replace state is read and ->is_tgtdev_for_dev_replace is set.  This
leads to a bogus decrement of ->rw_devices and sets off a WARN_ON in
__btrfs_close_devices if replace target device happens to be on the
lists and we fail early in the mount sequence.  Fix this by checking
the devid instead of ->is_tgtdev_for_dev_replace before the decrement:
for replace targets devid is always equal to BTRFS_DEV_REPLACE_DEVID.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

It is not used for anything.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

As we're hold a ref on looking up the extent map, we need to drop the ref
before returning to callers.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

free_device rcu callback, scheduled from btrfs_rm_dev_replace_srcdev,
can be processed before btrfs_scratch_superblock is called, which would
result in a use-after-free on btrfs_device contents.  Fix this by
zeroing the superblock before the rcu callback is registered.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The kernel log entries for device label %s and device fsid %pU
are missing the btrfs: prefix. Add those here.
Signed-off-by: NFrank Holton <fholton@gmail.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If replace was suspended by the umount, replace target device is added
to the fs_devices->alloc_list during a later mount.  This is obviously
wrong.  ->is_tgtdev_for_dev_replace is supposed to guard against that,
but ->is_tgtdev_for_dev_replace is (and can only ever be) initialized
*after* everything is opened and fs_devices lists are populated.  Fix
this by checking the devid instead: for replace targets it's always
equal to BTRFS_DEV_REPLACE_DEVID.

Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If there's an ongoing transaction when the uuid scan kthread attempts
to create one, the kthread will block, waiting for that transaction to
finish while it's keeping locks on the tree root, and in turn the existing
transaction is waiting for those locks to be free.

The stack trace reported by the kernel follows.

[36700.671601] INFO: task btrfs-uuid:15480 blocked for more than 120 seconds.
[36700.671602] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[36700.671602] btrfs-uuid      D 0000000000000000     0 15480      2 0x00000000
[36700.671604]  ffff880710bd5b88 0000000000000046 ffff8803d36ba850 0000000000030000
[36700.671605]  ffff8806d76dc530 ffff880710bd5fd8 ffff880710bd5fd8 ffff880710bd5fd8
[36700.671607]  ffff8808098ac530 ffff8806d76dc530 ffff880710bd5b98 ffff8805e4508e40
[36700.671608] Call Trace:
[36700.671610]  [<ffffffff816f36b9>] schedule+0x29/0x70
[36700.671620]  [<ffffffffa05a3bdf>] wait_current_trans.isra.33+0xbf/0x120 [btrfs]
[36700.671623]  [<ffffffff81066760>] ? add_wait_queue+0x60/0x60
[36700.671629]  [<ffffffffa05a5b06>] start_transaction+0x3d6/0x530 [btrfs]
[36700.671636]  [<ffffffffa05bb1f4>] ? btrfs_get_token_32+0x64/0xf0 [btrfs]
[36700.671642]  [<ffffffffa05a5fbb>] btrfs_start_transaction+0x1b/0x20 [btrfs]
[36700.671649]  [<ffffffffa05c8a81>] btrfs_uuid_scan_kthread+0x211/0x3d0 [btrfs]
[36700.671655]  [<ffffffffa05c8870>] ? __btrfs_open_devices+0x2a0/0x2a0 [btrfs]
[36700.671657]  [<ffffffff81065fa0>] kthread+0xc0/0xd0
[36700.671659]  [<ffffffff81065ee0>] ? flush_kthread_worker+0xb0/0xb0
[36700.671661]  [<ffffffff816fcd1c>] ret_from_fork+0x7c/0xb0
[36700.671662]  [<ffffffff81065ee0>] ? flush_kthread_worker+0xb0/0xb0
[36700.671663] INFO: task btrfs:15481 blocked for more than 120 seconds.
[36700.671664] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[36700.671665] btrfs           D 0000000000000000     0 15481  15212 0x00000004
[36700.671666]  ffff880248cbf4c8 0000000000000086 ffff8803d36ba700 ffff8801dbd5c280
[36700.671668]  ffff880807815c40 ffff880248cbffd8 ffff880248cbffd8 ffff880248cbffd8
[36700.671669]  ffff8805e86a0000 ffff880807815c40 ffff880248cbf4d8 ffff8801dbd5c280
[36700.671670] Call Trace:
[36700.671672]  [<ffffffff816f36b9>] schedule+0x29/0x70
[36700.671679]  [<ffffffffa05d9b0d>] btrfs_tree_lock+0x6d/0x230 [btrfs]
[36700.671680]  [<ffffffff81066760>] ? add_wait_queue+0x60/0x60
[36700.671685]  [<ffffffffa0582829>] btrfs_search_slot+0x999/0xb00 [btrfs]
[36700.671691]  [<ffffffffa05bd9de>] ? btrfs_lookup_first_ordered_extent+0x5e/0xb0 [btrfs]
[36700.671698]  [<ffffffffa05e3e54>] __btrfs_write_out_cache+0x8c4/0xa80 [btrfs]
[36700.671704]  [<ffffffffa05e4362>] btrfs_write_out_cache+0xb2/0xf0 [btrfs]
[36700.671710]  [<ffffffffa05c4441>] ? free_extent_buffer+0x61/0xc0 [btrfs]
[36700.671716]  [<ffffffffa0594c82>] btrfs_write_dirty_block_groups+0x562/0x650 [btrfs]
[36700.671723]  [<ffffffffa0610092>] commit_cowonly_roots+0x171/0x24b [btrfs]
[36700.671729]  [<ffffffffa05a4dde>] btrfs_commit_transaction+0x4fe/0xa10 [btrfs]
[36700.671735]  [<ffffffffa0610af3>] create_subvol+0x5c0/0x636 [btrfs]
[36700.671742]  [<ffffffffa05d49ff>] btrfs_mksubvol.isra.60+0x33f/0x3f0 [btrfs]
[36700.671747]  [<ffffffffa05d4bf2>] btrfs_ioctl_snap_create_transid+0x142/0x190 [btrfs]
[36700.671752]  [<ffffffffa05d4c6c>] ? btrfs_ioctl_snap_create+0x2c/0x80 [btrfs]
[36700.671757]  [<ffffffffa05d4c9e>] btrfs_ioctl_snap_create+0x5e/0x80 [btrfs]
[36700.671759]  [<ffffffff8113a764>] ? handle_pte_fault+0x84/0x920
[36700.671764]  [<ffffffffa05d87eb>] btrfs_ioctl+0xf0b/0x1d00 [btrfs]
[36700.671766]  [<ffffffff8113c120>] ? handle_mm_fault+0x210/0x310
[36700.671768]  [<ffffffff816f83a4>] ? __do_page_fault+0x284/0x4e0
[36700.671770]  [<ffffffff81180aa6>] do_vfs_ioctl+0x96/0x550
[36700.671772]  [<ffffffff81170fe3>] ? __sb_end_write+0x33/0x70
[36700.671774]  [<ffffffff81180ff1>] SyS_ioctl+0x91/0xb0
[36700.671775]  [<ffffffff816fcdc2>] system_call_fastpath+0x16/0x1b
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

AFAICT chunk 0 is no longer special, and so it should be restriped just
like every other chunk.  One reason for this change is us refusing the
relocation can lead to filesystems that can only be mounted ro, and
never rw -- see the bugzilla [1] for details.  The other reason is that
device removal code is already doing this: it will happily relocate
chunk 0 is part of shrinking the device.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=60594Reported-by: NXavier Bassery <xavier@bartica.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

I noticed that if I tried to mount a file system with -o degraded after having
done it once already we would fail to mount.  This is because the
fs_devices->missing count was getting bumped everytime we mounted, but not
getting reset whenever we unmounted.  To fix this we just drop the missing count
as we're closing devices to make sure this doesn't happen.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The handler for the ioctl BTRFS_IOC_FS_INFO was reading the
number of devices before acquiring the device list mutex.

This could lead to inconsistent results because the update of
the device list and the number of devices counter (amongst other
counters related to the device list) are updated in volumes.c
while holding the device list mutex - except for 2 places, one
was volumes.c:btrfs_prepare_sprout() and the other was
volumes.c:device_list_add().

For example, if we have 2 devices, with IDs 1 and 2 and then add
a new device, with ID 3, and while adding the device is in progress
an BTRFS_IOC_FS_INFO ioctl arrives, it could return a number of
devices of 2 and a max dev id of 3. This would be incorrect.

Also, this ioctl handler was reading the fsid while it can be
updated concurrently. This can happen when while a new device is
being added and the current filesystem is in seeding mode.
Example:

$ mkfs.btrfs -f /dev/sdb1
$ mkfs.btrfs -f /dev/sdb2
$ btrfstune -S 1 /dev/sdb1
$ mount /dev/sdb1 /mnt/test
$ btrfs device add /dev/sdb2 /mnt/test

If during the last step a BTRFS_IOC_FS_INFO ioctl was requested, it
could read an fsid that was never valid (some bits part of the old
fsid and others part of the new fsid). Also, it could read a number
of devices that doesn't match the number of devices in the list and
the max device id, as explained before.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This change fixes an issue when removing a device and writing
all super blocks run simultaneously. Here's the steps necessary
for the issue to happen:

1) disk-io.c:write_all_supers() gets a number of N devices from the
   super_copy, so it will not panic if it fails to write super blocks
   for N - 1 devices;

2) Then it tries to acquire the device_list_mutex, but blocks because
   volumes.c:btrfs_rm_device() got it first;

3) btrfs_rm_device() removes the device from the list, then unlocks the
   mutex and after the unlock it updates the number of devices in
   super_copy to N - 1.

4) write_all_supers() finally acquires the mutex, iterates over all the
   devices in the list and gets N - 1 errors, that is, it failed to write
   super blocks to all the devices;

5) Because write_all_supers() thinks there are a total of N devices, it
   considers N - 1 errors to be ok, and therefore won't panic.

So this change just makes sure that write_all_supers() reads the number
of devices from super_copy after it acquires the device_list_mutex.
Conversely, it changes btrfs_rm_device() to update the number of devices
in super_copy before it releases the device list mutex.

The code path to add a new device (volumes.c:btrfs_init_new_device),
already has the right behaviour: it updates the number of devices in
super_copy while holding the device_list_mutex.

The only code path that doesn't lock the device list mutex
before updating the number of devices in the super copy is
disk-io.c:next_root_backup(), called by open_ctree() during
mount time where concurrency issues can't happen.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Internally, btrfs_dev_extent_chunk_tree_uuid() calculates an unsigned long,
but casts it to a pointer, while all callers cast it to unsigned long
again.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

All callers of btrfs_device_fsid() cast its return type to unsigned long.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

All callers of btrfs_device_uuid() cast its return type to unsigned long.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

It turns out we don't properly rollback in-core btrfs_device state on
umount.  We zero out ->bdev, ->in_fs_metadata and that's about it.  In
particular, we don't zero out ->generation, and this can lead to us
refusing a mount -- a non-NULL fs_devices->latest_bdev is essential, but
btrfs_close_extra_devices will happily assign NULL to ->latest_bdev if
the first device on the dev_list happens to be missing and consequently
has no bdev attached.  This happens because since commit a6b0d5c8
btrfs_close_extra_devices adjusts ->latest_bdev, and in doing that,
relies on the ->generation.  Fix this, and possibly other problems, by
zeroing out everything except for what device_list_add sets, so that a
mount right after insmod and 'btrfs dev scan' is no different from any
later mount in this respect.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

In the spirit of btrfs_alloc_device, add a helper for allocating and
doing some common initialization of btrfs_fs_devices struct.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Currently btrfs_device is allocated ad-hoc in a few different places,
and as a result not all fields are initialized properly.  In particular,
readahead state is only initialized in device_list_add (at scan time),
and not in btrfs_init_new_device (when the new device is added with
'btrfs dev add').  Fix this by adding an allocation helper and switch
everybody but __btrfs_close_devices to it.  (__btrfs_close_devices is
dealt with in a later commit.)
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

find_next_devid() knows which root to search, so it should take an
fs_info instead of an arbitrary root.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If the filesystem was mounted with an old kernel that was not
aware of the UUID tree, this is detected by looking at the
uuid_tree_generation field of the superblock (similar to how
the free space cache is doing it). If a mismatch is detected
at mount time, a thread is started that does two things:
1. Iterate through the UUID tree, check each entry, delete those
   entries that are not valid anymore (i.e., the subvol does not
   exist anymore or the value changed).
2. Iterate through the root tree, for each found subvolume, add
   the UUID tree entries for the subvolume (if they are not
   already there).

This mechanism is also used to handle and repair errors that
happened during the initial creation and filling of the tree.
The update of the uuid_tree_generation field (which indicates
that the state of the UUID tree is up to date) is blocked until
all create and repair operations are successfully completed.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

When the UUID tree is initially created, a task is spawned that
walks through the root tree. For each found subvolume root_item,
the uuid and received_uuid entries in the UUID tree are added.
This is such a quick operation so that in case somebody wants
to unmount the filesystem while the task is still running, the
unmount is delayed until the UUID tree building task is finished.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This tree is not created by mkfs.btrfs. Therefore when a filesystem
is mounted writable and the UUID tree does not exist, this tree is
created if required. The tree is also added to the fs_info structure
and initialized, but this commit does not yet read or write UUID tree
elements.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

make C=2 fs/btrfs/ CF=-D__CHECK_ENDIAN__

I tried to filter out the warnings for which patches have already
been sent to the mailing list, pending for inclusion in btrfs-next.

All these changes should be obviously safe.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

If we bail out when the stripe alloc fails, we need to undo the
earlier allocation of raid_map.
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

After reading all device items from the chunk tree, don't
exit the loop and then navigate down the tree again to find
the chunk items. Instead just read all device items and
chunk items with a single tree search. This is possible
because all device items are found before any chunk item in
the chunks tree.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Some codes still use the cpu_to_lexx instead of the
BTRFS_SETGET_STACK_FUNCS declared in ctree.h.

Also added some BTRFS_SETGET_STACK_FUNCS for btrfs_header btrfs_timespec
and other structures.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaoxie@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The log message level 'critical' is verbose enough, 'emergency' beeps on
all terminals.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Device scanning waits on the uuid_mutex, which can result in a very long
wait if dev delete is shrinking the device.
Signed-off-by: NCarey Underwood <cwillu@cwillu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

PTR_RET is now deprecated. Use PTR_ERR_OR_ZERO instead.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

When adjusting the enospc rules for relocation I ran into a deadlock because we
were relocating the only system chunk and that forced us to try and allocate a
new system chunk while holding locks in the chunk tree, which caused us to
deadlock.  To fix this I've moved all of the dev extent addition and chunk
addition out to the delayed chunk completion stuff.  We still keep the in-memory
stuff which makes sure everything is consistent.

One change I had to make was to search the commit root of the device tree to
find a free dev extent, and hold onto any chunk em's that we allocated in that
transaction so we do not allocate the same dev extent twice.  This has the side
effect of fixing a bug with balance that has been there ever since balance
existed.  Basically you can free a block group and it's dev extent and then
immediately allocate that dev extent for a new block group and write stuff to
that dev extent, all within the same transaction.  So if you happen to crash
during a balance you could come back to a completely broken file system.  This
patch should keep these sort of things from happening in the future since we
won't be able to allocate free'd dev extents until after the transaction
commits.  This has passed all of the xfstests and my super annoying stress test
followed by a balance.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Now reading the data from the target device of the replace operation is allowed,
so the mirror number that is greater than the stripes number of a chunk is valid,
we will tune it when we find there is no target device later. Fix it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

when user runs command btrfs dev del the raid requisite error if any
goes to the /var/log/messages, its not good idea to clutter messages
with these user (knowledge) errors, further user don't have to review
the system messages to know problem with the cli it should be dropped
to the user as part of the cli return.

to bring this feature created a set of the ERROR defined
BTRFS_ERROR_DEV* error codes and created their error string.

I expect this enum to be added with other error which we might
want to communicate to the user land

v3:
moved the code with in the file no logical change

v1->v2:
introduce error codes for the device mgmt usage

v1:
adds a parameter in the ioctl arg struct to carry the error string
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

There are several functions whose code is similar, such as
  btrfs_find_last_root()
  btrfs_read_fs_root_no_radix()

Besides that, some functions are invoked twice, it is unnecessary,
for example, we are sure that all roots which is found in
  btrfs_find_orphan_roots()
have their orphan items, so it is unnecessary to check the orphan
item again.

So cleanup it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>