When a new subvolume or snapshot is created, a new UUID item is added
to the UUID tree. Such items are removed when the subvolume is deleted.
The ioctl to set the received subvolume UUID is also touched and will
now also add this received UUID into the UUID tree together with the
ID of the subvolume. The latter is also done when read-only snapshots
are created which inherit all the send/receive information from the
parent subvolume.

User mode programs use the BTRFS_IOC_TREE_SEARCH ioctl to search and
read in the UUID tree.
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 the inode ref key was not found and the current leaf slot
was 0 (first item in the leaf) the code would always return
-ENOENT. This was not correct because the desired inode ref
item might be the last item in the previous leaf.
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>

If the path doesn't fit in the input buffer, return ENAMETOOLONG
instead of returning with a success code (0) and a partially
filled and right justified buffer.

Also removed useless buffer pointer check outside the while loop.
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>

Eric pointed out that btrfs will happily allow you to delete the default subvol.
This is a problem obviously since the next time you go to mount the file system
it will freak out because it can't find the root.  Fix this by adding a check to
see if our default subvol points to the subvol we are trying to delete, and if
it does not allowing it to happen.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

This patch adds an ioctl, BTRFS_IOC_FILE_EXTENT_SAME which will try to
de-duplicate a list of extents across a range of files.

Internally, the ioctl re-uses code from the clone ioctl. This avoids
rewriting a large chunk of extent handling code.

Userspace passes in an array of file, offset pairs along with a length
argument. The ioctl will then (for each dedupe) do a byte-by-byte comparison
of the user data before deduping the extent. Status and number of bytes
deduped are returned for each operation.
Signed-off-by: NMark Fasheh <mfasheh@suse.de>
Reviewed-by: NZach Brown <zab@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

There's some 250+ lines here that are easily encapsulated into their own
function. I don't change how anything works here, just create and document
the new btrfs_clone() function from btrfs_ioctl_clone() code.
Signed-off-by: NMark Fasheh <mfasheh@suse.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

The range locking in btrfs_ioctl_clone is trivially broken out into it's own
function. This reduces the complexity of btrfs_ioctl_clone() by a small bit
and makes that locking code available to future functions in
fs/btrfs/ioctl.c
Signed-off-by: NMark Fasheh <mfasheh@suse.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

btrfs_ioctl_get_fslabel() and btrfs_ioctl_set_fslabel()
used root->fs_info->volume_mutex mutex which caused operations
like balance to block set/get label operation until its
completion and generally balance operation takes a long
time to complete, so it will be annoying to the user when
cli appears hung

also this patch will add a bit of optimization within
the btrfs_ioctl_get_falabel() function.

v1->v2:
   use fs_info->super_lock instead of uuid_mutex
Signed-off-by: NAnand Jain <anand.jain@oracle.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>

I recently did some ENOSPC testing that involved filling the disk
while create and removing snapshots in a loop. During the test cycle,
I ran into an ENOSPC when trying to remove a snapshot, leaving the fs
stuck in ENOSPC even after a umount/mount cycle.

This patch allow subvolume removal to fall back onto the global
block reservation in order to succeed when it would have failed
otherwise.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <chris.mason@fusionio.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We did not allow file data clone within the same file because of
deadlock issues.

However, we now use nested lock to avoid deadlock between the
parent directory and the child file.

So it's safe to do file clone within the same file when the two
ranges are not overlapped.
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
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>

Before applying this patch, we need flush all the delalloc inodes in
the fs when we want to create a snapshot, it wastes time, and make
the transaction commit be blocked for a long time. It means some other
user operation would also be blocked for a long time.

This patch improves this problem, we just flush the delalloc inodes that
in the source trees before snapshot creation, so the transaction commit
will complete quickly.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

btrfs_read_fs_root_no_name() already checks if btrfs_root_refs()
is zero and returns ENOENT in this case. There is no need to do
it again in six places.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

We don't need to copy it back to user side as it remains unchanged.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

btrfs_qgroup_wait_for_completion waits until the currently running qgroup
operation completes. It returns immediately when no rescan process is in
progress. This is useful to automate things around the rescan process (e.g.
testing).
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The search ioctl skips items that are too large for a result buffer, but
inline items of a certain size occuring before any search result is
found would trigger an overflow and stop the search entirely.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=57641

Cc: stable@vger.kernel.org
Signed-off-by: NGabriel de Perthuis <g2p.code+btrfs@gmail.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

There's a theoretical possibility of reading stale (or even more
theoretically, freed) data from DEV_INFO ioctl when the device would
disappear between an early mutex unlock and data being copied from the
device structure.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.

removed functions:

btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()

btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.

ulist.c functions are left, another patch will take care of those.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

If qgroup tracking is out of sync, a rescan operation can be started. It
iterates the complete extent tree and recalculates all qgroup tracking data.
This is an expensive operation and should not be used unless required.

A filesystem under rescan can still be umounted. The rescan continues on the
next mount.  Status information is provided with a separate ioctl while a
rescan operation is in progress.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

We need such a sanity check for wrong start when we defrag a file, otherwise,
even with a wrong start that's larger than file size, we can end up changing
not only inode's force compress flag but also FS's incompat flags.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Steps to reproduce:
	mkfs.btrfs <disk>
	mount <disk> <mnt>
	btrfs quota enable <mnt>
	btrfs sub create <mnt>/subv
	btrfs qgroup limit 10K <mnt>/subv
	btrfs quota disable <mnt>/subv

It is wrong for qgroup to reserve when disabling quota,
so just use tree_root to avoid edquot when disabling quota.
Signed-off-by: NWang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Creating the subvolume/snapshots(including root subvolume) qgroup
auotomatically when enabling quota.
Signed-off-by: NWang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The subvolume ioctls block on the parent directory mutex that can be
held by other concurrent snapshot activity for a long time. Give the
user at least some chance to get out of this situation by allowing
to send a kill signal.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Commit 5ac00add added a testnset mutex and code that disallows
running administrative tasks in parallel. It is prevented that
the device add/delete/balance/replace/resize operations are
started in parallel. By mistake, the defragmentation operation
was included in the check for mutually exclusiveness as well.
This is fixed with this commit.
Signed-off-by: NStefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

If the async transaction commitment failed, we need close the
current transaction handler, or the current transaction will be
blocked to commit because of this orphan handler.

We fix the problem by doing sync transaction commitment, that is
to invoke btrfs_commit_transaction().
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

There are several bugs at error path of create_snapshot() when the
transaction commitment failed.
- access the freed transaction handler. At the end of the
  transaction commitment, the transaction handler was freed, so we
  should not access it after the transaction commitment.
- we were not aware of the error which happened during the snapshot
  creation if we submitted a async transaction commitment.
- pending snapshot access vs pending snapshot free. when something
  wrong happened after we submitted a async transaction commitment,
  the transaction committer would cleanup the pending snapshots and
  free them. But the snapshot creators were not aware of it, they
  would access the freed pending snapshots.

This patch fixes the above problems by:
- remove the dangerous code that accessed the freed handler
- assign ->error if the error happens during the snapshot creation
- the transaction committer doesn't free the pending snapshots,
  just assigns the error number and evicts them before we unblock
  the transaction.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

When deleting a snapshot/subvolume, we need remove root ref/backref,
dir entries and update the dir inode, so we must reserve free space
for those operations.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

There are two problems in the space reservation of the snapshot/
subvolume creation.
- don't reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
  the free space reservation. we need reserve free space for
  7 items, but in qgroup reservation, we need reserve space only
  for 3 items.

So we implement new metadata reservation functions for the
snapshot/subvolume creation.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Since we have grabbed the parent inode at the beginning of the
snapshot creation, and both sync and async snapshot creation
release it after the pending snapshots are actually created,
it is safe to access the parent inode directly during the snapshot
creation, we needn't use dget_parent/dput to fix the parent dentry
and get the dir inode.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Right now inode cache inode is treated as the same as space cache
inode, ie. keep inode in memory till putting super.

But this leads to an awkward situation.

If we're going to delete a snapshot/subvolume, btrfs will not
actually delete it and return free space, but will add it to dead
roots list until the last inode on this snap/subvol being destroyed.
Then we'll fetch deleted roots and cleanup them via cleaner thread.

So here is the problem, if we enable inode cache option, each
snap/subvol has a cached inode which is used to store inode allcation
information.  And this cache inode will be kept in memory, as the above
said.  So with inode cache, snap/subvol can only be added into
dead roots list during freeing roots stage in umount, so that we can
ONLY get space back after another remount(we cleanup dead roots on mount).

But the real thing is we'll no more use the snap/subvol if we mark it
deleted, so we can safely iput its cache inode when we delete snap/subvol.

Another thing is that we need to change the rules of droping inode, we
don't keep snap/subvol's cache inode in memory till end so that we can
add snap/subvol into dead roots list in time.
Reported-by: NMitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

In some cases, we need commit the current transaction, but don't want
to start a new one if there is no running transaction, so we introduce
the function - btrfs_attach_transaction(), which can catch the current
transaction, and return -ENOENT if there is no running transaction.

But no running transaction doesn't mean the current transction completely,
because we removed the running transaction before it completes. In some
cases, it doesn't matter. But in some special cases, such as freeze fs, we
hope the transaction is fully on disk, it will introduce some bugs, for
example, we may feeze the fs and dump the data in the disk, if the transction
doesn't complete, we would dump inconsistent data. So we need fix the above
problem for those cases.

We fixes this problem by introducing a function:
	btrfs_attach_transaction_barrier()
if we hope all the transaction is fully on the disk, even they are not
running, we can use this function.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

With this new ioctl(2) BTRFS_IOC_SET_FSLABEL, we can set/change the label of a mounted file system.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: NGoffredo Baroncelli <kreijack@inwind.it>
Reviewed-by: NDavid Sterba <dsterba@suse.cz>
Reviewed-by: NGoffredo Baroncelli <kreijack@inwind.it>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

Add a new ioctl(2) BTRFS_IOC_GET_FSLABLE, so that we can get the label upon a mounted filesystem.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Goffredo Baroncelli <kreijack@inwind.it>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The defrag operation can take very long, we want to have a way how to
cancel it. The code checks for a pending signal at safe points in the
defrag loops and returns EAGAIN. This means a user can press ^C after
running 'btrfs fi defrag', woks for both defrag modes, files and root.

Returning from the command was instant in my light tests, but may take
longer depending on the aging factor of the filesystem.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The argument "inherit" of btrfs_ioctl_snap_create_transid() was assigned
to NULL during we created the snapshots, so we didn't free it though we
called kfree() in the caller.

But since we are sure the snapshot creation is done after the function -
btrfs_ioctl_snap_create_transid() - completes, it is safe that we don't
assign the pointer "inherit" to NULL, and just free it in the caller of
btrfs_ioctl_snap_create_transid(). In this way, the code can become more
readable.
Reported-by: NAlex Lyakas <alex.btrfs@zadarastorage.com>
Cc: Arne Jansen <sensille@gmx.net>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The entry point at the defrag ioctl always sets "cache only" to 0;
the codepaths haven't run for a long time as far as I can
tell.  Chris says they're dead code, so remove them.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The header file will then be installed under /usr/include/linux so that
userspace applications can refer to Btrfs ioctls by name and use the same
structs used internally in the kernel.
Signed-off-by: NFilipe Brandenburger <filbranden@google.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>