The search ioctl was working well for finding tree roots, but using it for
generic searches requires a few changes to how the keys are advanced.
This treats the search control min fields for objectid, type and offset
more like a key, where we drop the offset to zero once we bump the type,
etc.

The downside of this is that we are changing the min_type and min_offset
fields during the search, and so the ioctl caller needs extra checks to make sure
the keys in the result are the ones it wanted.

This also changes key_in_sk to use btrfs_comp_cpu_keys, just to make
things more readable.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The space_info ioctl was using copy_to_user inside rcu_read_lock.  This
commit changes things to copy into a buffer first and then dump the
result down to userland.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

key->type is u8, not u64.

fs/btrfs/ioctl.c: In function 'copy_to_sk':
fs/btrfs/ioctl.c:1024: warning: comparison is always true due to limited range of data type
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

GFP_FS must be masked out, NOFS can't be or'd in.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

After callling submit_bio, the bio can be freed at any time.  The
btrfs submission thread helper was checking the bio flags too late,
which might not give the correct answer.

When CONFIG_DEBUG_PAGE_ALLOC is turned on, it can lead to oopsen.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We can use btrfs_stack_device_id() to get dev_item->devid
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Use memparse() instead of its own private implementation.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Signed-off-by: NChris Mason <chris.mason@oracle.com>

df is a very loaded question in btrfs.  This gives us a way to get the per-space
usage information so we can tell exactly what is in use where.  This will help
us figure out ENOSPC problems, and help users better understand where their disk
space is going.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch just goes through and fixes everybody that does

lock_extent()
blah
unlock_extent()

to use

lock_extent_bits()
blah
unlock_extent_cached()

and pass around a extent_state so we only have to do the searches once per
function.  This gives me about a 3 mb/s boots on my random write test.  I have
not converted some things, like the relocation and ioctl's, since they aren't
heavily used and the relocation stuff is in the middle of being re-written.  I
also changed the clear_extent_bit() to only unset the cached state if we are
clearing EXTENT_LOCKED and related stuff, so we can do things like this

lock_extent_bits()
clear delalloc bits
unlock_extent_cached()

without losing our cached state.  I tested this thoroughly and turned on
LEAK_DEBUG to make sure we weren't leaking extent states, everything worked out
fine.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When finishing io we run btrfs_dec_test_ordered_pending, and then immediately
run btrfs_lookup_ordered_extent, but btrfs_dec_test_ordered_pending does that
already, so we're searching twice when we don't have to.  This patch lets us
pass a btrfs_ordered_extent in to btrfs_dec_test_ordered_pending so if we do
complete io on that ordered extent we can just use the one we found then instead
of having to do another btrfs_lookup_ordered_extent.  This made my fio job with
the other patch go from 24 mb/s to 29 mb/s.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch makes us cache the extent state we find in find_delalloc_range since
we'll have to lock the extent later on in the function.  This will keep us from
re-searching for the rang when we try to lock the extent.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The ordered tree used to need a mutex, but currently all we use it for is to
protect the rb_tree, and a spin_lock is just fine for that.  Using a spin_lock
instead makes dbench run a little faster, 58 mb/s instead of 51 mb/s, and have
less latency, 3445.138 ms instead of 3820.633 ms.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The endio is done at reverse order of bio vectors.

That means for a sequential read, the page first submitted will finish
last in a bio. Considering we will do checksum (making cache hot) for
every page, this does introduce delay (and chance to squeeze cache used
soon) for pages submitted at the begining.

I don't observe obvious performance difference with below patch at my
simple test, but seems more natural to finish read in the order they are
submitted.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs_mkdir() must jump to the place of ending transaction after
btrfs_find_free_objectid() failed. Or this transaction can't end.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Flush any delalloc extents when we create a snapshot, so that recently
written file data is always included in the snapshot.

A later commit will add the ability to snapshot without the flush, but
most people expect flushing.
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The way we report df usage is way confusing for everybody, including some other
utilities (bacula for one).  So this patch makes df a little bit more
understandable.  First we make used actually count the total amount of used
space in all space info's.  This will give us a real view of how much disk space
is in use.  Second, for blocks available, only count data space.  This makes
things like bacula work because it says 0 when you can no longer write anymore
data to the disk.  I think this is a nice compromise, since you will end up with
something like the following

[root@alpha ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                      148G   30G  111G  21% /
/dev/sda1             194M  116M   68M  64% /boot
tmpfs                 985M   12K  985M   1% /dev/shm
/dev/mapper/VolGroup-LogVol02
                      145G  140G     0 100% /mnt/btrfs-test

Compare this with btrfsctl -i output

[root@alpha btrfs-progs-unstable]# ./btrfsctl -i /mnt/btrfs-test/
Metadata, DUP: total=4.62GB, used=2.46GB
System, DUP: total=8.00MB, used=24.00KB
Data: total=134.80GB, used=134.80GB
Metadata: total=8.00MB, used=0.00
System: total=4.00MB, used=0.00
operation complete

This way we show that there is no more data space to be used, but we have
another 5GB of space left for metadata.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When we scan devices in a multi-device filesystem, we memorize the original
name.  If the device gets a new name, later scans don't update the
in-kernel structures related to it, and we're not able to mount the
filesystem.

This patch updates device name during scaning.
Signed-off-by: NTARUISI Hiroaki <taruishi.hiroak@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The btrfs defrag ioctl was limited to doing the entire file.  This
commit adds a new interface that can defrag a specific range inside
the file.

It can also force compression on the file, allowing you to selectively
compress individual files after they were created, even when mount -o
compress isn't turned on.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The btrfs defrag ioctl had some bugs around delalloc accounting, and it
wasn't properly skipping pages that were not in the mapping.

It wasn't properly clearing the page checked flag, which could make the
writeback code ignore the page forever while pinning it as dirty.

This commit fixes those problems and makes defrag a little smarter.  It
skips holes and it doesn't waste time defragging large extents.  If a
tiny extent comes before a very large extent, it will defrag both of
them to make sure the tiny extent ends up next to something big.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The submit_bio helper thread can decide to loop back around to
service more bios.  This commit forces it to unplug first, which helps
reduce the latency seen by submitters.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Since theres not a good way to make sure the user sees the original default root
tree id, and not to mention it's 5 so is way different than any other volume,
just make subvol=0 mount the original default root.  This makes it a bit easier
for users to handle in the long run.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch needs to go along with my previous patch.  This lets us set the
default dir item's location to whatever root we want to use as our default
mounting subvol.  With this we don't have to use mount -o subvol=<tree id>
anymore to mount a different subvol, we can just set the new one and it will
just magically work.  I've done some moderate testing with this, mostly just
switching the default mount around, mounting subvols and the default mount at
the same time and such, everything seems to work.  Thanks,

Older kernels would generally be able to still mount the filesystem with the
default subvolume set, but it would result in a different volume being mounted,
which could be an even more unpleasant suprise for users.  So if you set your
default subvolume, you can't go back to older kernels.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This work is in preperation for being able to set a different root as the
default mounting root.

There is currently a problem with how we mount subvolumes.  We cannot currently
mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the
default subvolume.  So say you take a snapshot of the default subvolume and call
it snap1, and then take a snapshot of snap1 and call it snap2, so now you have

/
/snap1
/snap1/snap2

as your available volumes.  Currently you can only mount / and /snap1,
you cannot mount /snap1/snap2.  To fix this problem instead of passing
subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is
the tree id that gets spit out via the subvolume listing you get from
the subvolume listing patches (btrfs filesystem list).  This allows us
to mount /, /snap1 and /snap1/snap2 as the root volume.

In addition to the above, we also now read the default dir item in the
tree root to get the root key that it points to.  For now this just
points at what has always been the default subvolme, but later on I plan
to change it to point at whatever root you want to be the new default
root, so you can just set the default mount and not have to mount with
-o subvolid=<treeid>.  I tested this out with the above scenario and it
worked perfectly.  Thanks,

mount -o subvol operates inside the selected subvolid.  For example:

mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt

/mnt will have the snap1 directory for the subvolume with id
256.

mount -o subvol=snap /dev/xxx /mnt

/mnt will be the snap directory of whatever the default subvolume
is.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Our set/get functions for compat_ro_flags actually look at compat_flags.  This
will mess any attempt to use compat flags up.  The fix is obvious.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The search ioctl is a generic tool for doing btree searches from
userland applications.  The first user of the search ioctl is a
subvolume listing feature, but we'll also use it to find new
files in a subvolume.

The search ioctl allows you to specify min and max keys to search for,
along with min and max transid.  It returns the items along with a
header that includes the item key.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This will be used by the inode lookup ioctl.
Signed-off-by: NTARUISI Hiroaki <taruishi.hiroak@jp.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We kstrdup the options string, but then strsep screws with the pointer,
so when we kfree() it, we're not giving it the right pointer.
Tested-by: NAndy Lutomirski <luto@mit.edu>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs inialize rb trees in quite a number of places by settin rb_node =
NULL;  The problem with this is that 17d9ddc7 in the
linux-next tree adds a new field to that struct which needs to be NULL for
the new rbtree library code to work properly.  This patch uses RB_ROOT as
the intializer so all of the relevant fields will be NULL'd.  Without the
patch I get a panic.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

My test do: fallocate a big file and do write. The file is 512M, but
after file write is done btrfs-debug-tree shows:
item 6 key (257 EXTENT_DATA 0) itemoff 3516 itemsize 53
                extent data disk byte 1103101952 nr 536870912
                extent data offset 0 nr 399634432 ram 536870912
                extent compression 0
Looks like a regression introducted by
6c7d54ac, where we set wrong slot.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NYan Zheng <zheng.yan@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This version of the i_size fix for fallocate makes sure we only update
the i_size when the current fallocate is really operating outside of
i_size.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When running the following fio job

[torrent]
filename=torrent-test
rw=randwrite
size=4g
filesize=4g
bs=4k
ioengine=sync

you would see long stalls where no work was being done.  That is because we were
doing all this extra work to read in the file extent outside of the transaction,
however in the random io case this ends up hurting us because the file extents
are not there to begin with.  So axe this logic, since we end up reading in the
file extent when we go to update it anyway.  This took the fio job from 11 mb/s
with several ~10 second stalls to 24 mb/s to a couple of 1-2 second stalls.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When dropping a empty tree, walk_down_tree() skips checking
extent information for the tree root. This will triggers a
BUG_ON in walk_up_proc().
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Mounting a bad filesystem caused a BUG_ON(). The following is steps to
reproduce it.
 # mkfs.btrfs /dev/sda2
 # mount /dev/sda2 /mnt
 # mkfs.btrfs /dev/sda1 /dev/sda2
 (the program says that /dev/sda2 was mounted, and then exits. )
 # umount /mnt
 # mount /dev/sda1 /mnt

At the third step, mkfs.btrfs exited in the way of make filesystem. So the
initialization of the filesystem didn't finish. So the filesystem was bad, and
it caused BUG_ON() when mounting it. But BUG_ON() should be called by the wrong
code, not user's operation, so I think it is a bug of btrfs.

This patch fixes it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

It appears the error return should be negative
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Increase extent buffer's reference count while holding the lock.
Otherwise it can race with try_release_extent_buffer.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If you have a disk failure in RAID1 and then add a new disk to the
array, and then try to remove the missing volume, it will fail.  The
reason is the sanity check only looks at the total number of rw devices,
which is just 2 because we have 2 good disks and 1 bad one.  Instead
check the total number of devices in the array to make sure we can
actually remove the device.  Tested this with a failed disk setup and
with this test we can now run

btrfs-vol -r missing /mount/point

and it works fine.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Hit this problem while testing RAID1 failure stuff.  open_bdev_exclusive
returns ERR_PTR(), not NULL.  So change the return value properly.  This
is important if you accidently specify a device that doesn't exist when
trying to add a new device to an array, you will panic the box
dereferencing bdev.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

If a RAID setup has chunks that span multiple disks, and one of those
disks has failed, btrfs_chunk_readonly will return 1 since one of the
disks in that chunk's stripes is dead and therefore not writeable.  So
instead if we are in degraded mode, return 0 so we can go ahead and
allocate stuff.  Without this patch all of the block groups in a RAID1
setup will end up read-only, which will mean we can't add new disks to
the array since we won't be able to make allocations.
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch revert's commit

6c090a11

Since it introduces this problem where we can run orphan cleanup on a
volume that can have orphan entries re-added.  Instead of my original
fix, Yan Zheng pointed out that we can just revert my original fix and
then run the orphan cleanup in open_ctree after we look up the fs_root.
I have tested this with all the tests that gave me problems and this
patch fixes both problems.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>