This is used by the inode lookup ioctl to follow all the backrefs up
to the subvol root.  But the search being done would sometimes land one
past the last item in the leaf instead of finding the backref.

This changes the search to look for the highest possible backref and hop
back one item.  It also fixes a leaked path on failure to find the root.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When a root id of 0 is sent to the inode lookup ioctl, it will
use the root of the file we're ioctling and pass the root id
back to userland along with the results.

This allows userland to do searches based on that root later on.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The search ioctl was skipping large items entirely (ones that are too
big for the results buffer).  This changes things to at least copy
the item header so that we can send information about the item back to
userland.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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>

Use bitmap_weight() instead of doing hweight32() for each u32 element in
the page.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

jffs2 uses rb_node = NULL; to zero rb_root.

The problem with this is that 17d9ddc7 ("rbtree: Add
support for augmented rbtrees") in the linux-next tree adds a new field
to that struct which needs to be NULL as well.  This patch uses RB_ROOT
as the intializer so all of the relevant fields will be NULL'd.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Eric Paris <eparis@redhat.com>
Acked-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we are doing a forced shutdown, we can get lots of noise about
delalloc pages being discarded. This is happens by design during a
forced shutdown, so don't spam the logs with these messages.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Re-apply a commit that had been reverted due to regressions
that have since been fixed.

    From 95f8e302 Mon Sep 17 00:00:00 2001
    From: Nick Piggin <npiggin@suse.de>
    Date: Tue, 6 Jan 2009 14:43:09 +1100

    Implement XFS's large buffer support with the new vmap APIs. See the vmap
    rewrite (db64fe02) for some numbers. The biggest improvement that comes from
    using the new APIs is avoiding the global KVA allocation lock on every call.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Only modifications here were a minor reformat, plus making the patch
apply given the new use of xfs_buf_is_vmapped().
Modified-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Re-apply a commit that had been reverted due to regressions
that have since been fixed.

    Original commit: d2859751
    Author: Nick Piggin <npiggin@suse.de>
    Date: Tue, 6 Jan 2009 14:40:44 +1100

    XFS's vmap batching simply defers a number (up to 64) of vunmaps,
    and keeps track of them in a list. To purge the batch, it just goes
    through the list and calls vunamp on each one. This is pretty poor:
    a global TLB flush is generally still performed on each vunmap, with
    the most expensive parts of the operation being the broadcast IPIs
    and locking involved in the SMP callouts, and the locking involved
    in the vmap management -- none of these are avoided by just batching
    up the calls. I'm actually surprised it ever made much difference.
    (Now that the lazy vmap allocator is upstream, this description is
    not quite right, but the vunmap batching still doesn't seem to do
    much).

    Rip all this logic out of XFS completely. I will improve vmap
    performance and scalability directly in subsequent patch.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The only change I made was to use the "new" xfs_buf_is_vmapped()
function in a place it had been open-coded in the original.
Modified-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.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>

bdi_unregister is called by nfs_put_super which is only called by
generic_shutdown_super if ->s_root is not NULL.  So if we error out
in a circumstance where we called nfs_bdi_register (i.e. server !=
NULL) but have not set s_root, then we need to call bdi_unregister
explicitly in nfs_get_sb and various other *_get_sb() functions.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I fixed the indent level.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NSteve French <sfrench@us.ibm.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>

This kills the following checkpatch warnings:

 WARNING: unnecessary whitespace before a quoted newline
 #869: FILE: super.c:869:
 +     	           "remount to a different snapshot. \n",

 WARNING: unnecessary whitespace before a quoted newline
 #389: FILE: the_nilfs.c:389:
 +     	    printk(KERN_ERR "NILFS: too short segment. \n");
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This kills the following checkpatch warnings:

 WARNING: please, no space before tabs
 #74: FILE: segment.h:74:
 +^Iunsigned ^I^Iflags;$

 WARNING: please, no space before tabs
 #35: FILE: segbuf.c:35:
 +^Iint ^I^I^Istart, end; /* The region to be submitted */$
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

This fixes various typos I found in comments of nilfs2.
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>