Snapshot creation has two phases.  One is the initial snapshot setup,
and the second is done during commit, while nobody is allowed to modify
the root we are snapshotting.

The delayed metadata insertion code can break that rule, it does a
delayed inode update on the inode of the parent of the snapshot,
and delayed directory item insertion.

This makes sure to run the pending delayed operations before we
record the snapshot root, which avoids corruptions.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When allocation fails in btrfs_read_fs_root_no_name, ret is not set
although it is returned, holding a garbage value.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Reviewed-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We have migrated the space for the delayed inode items from
trans_block_rsv to global_block_rsv, but we forgot to set trans->block_rsv to
global_block_rsv when we doing delayed inode operations, and the following Oops
happened:

[ 9792.654889] ------------[ cut here ]------------
[ 9792.654898] WARNING: at fs/btrfs/extent-tree.c:5681
btrfs_alloc_free_block+0xca/0x27c [btrfs]()
[ 9792.654899] Hardware name: To Be Filled By O.E.M.
[ 9792.654900] Modules linked in: btrfs zlib_deflate libcrc32c
ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables
arc4 rt61pci rt2x00pci rt2x00lib snd_hda_codec_hdmi mac80211
snd_hda_codec_realtek cfg80211 snd_hda_intel edac_core snd_seq rfkill
pcspkr serio_raw snd_hda_codec eeprom_93cx6 edac_mce_amd sp5100_tco
i2c_piix4 k10temp snd_hwdep snd_seq_device snd_pcm floppy r8169 xhci_hcd
mii snd_timer snd soundcore snd_page_alloc ipv6 firewire_ohci pata_acpi
ata_generic firewire_core pata_via crc_itu_t radeon ttm drm_kms_helper
drm i2c_algo_bit i2c_core [last unloaded: scsi_wait_scan]
[ 9792.654919] Pid: 2762, comm: rm Tainted: G        W   2.6.39+ #1
[ 9792.654920] Call Trace:
[ 9792.654922]  [<ffffffff81053c4a>] warn_slowpath_common+0x83/0x9b
[ 9792.654925]  [<ffffffff81053c7c>] warn_slowpath_null+0x1a/0x1c
[ 9792.654933]  [<ffffffffa038e747>] btrfs_alloc_free_block+0xca/0x27c [btrfs]
[ 9792.654945]  [<ffffffffa03b8562>] ? map_extent_buffer+0x6e/0xa8 [btrfs]
[ 9792.654953]  [<ffffffffa038189b>] __btrfs_cow_block+0xfc/0x30c [btrfs]
[ 9792.654963]  [<ffffffffa0396aa6>] ? btrfs_buffer_uptodate+0x47/0x58 [btrfs]
[ 9792.654970]  [<ffffffffa0382e48>] ? read_block_for_search+0x94/0x368 [btrfs]
[ 9792.654978]  [<ffffffffa0381ba9>] btrfs_cow_block+0xfe/0x146 [btrfs]
[ 9792.654986]  [<ffffffffa03848b0>] btrfs_search_slot+0x14d/0x4b6 [btrfs]
[ 9792.654997]  [<ffffffffa03b8562>] ? map_extent_buffer+0x6e/0xa8 [btrfs]
[ 9792.655022]  [<ffffffffa03938e8>] btrfs_lookup_inode+0x2f/0x8f [btrfs]
[ 9792.655025]  [<ffffffff8147afac>] ? _cond_resched+0xe/0x22
[ 9792.655027]  [<ffffffff8147b892>] ? mutex_lock+0x29/0x50
[ 9792.655039]  [<ffffffffa03d41b1>] btrfs_update_delayed_inode+0x72/0x137 [btrfs]
[ 9792.655051]  [<ffffffffa03d4ea2>] btrfs_run_delayed_items+0x90/0xdb [btrfs]
[ 9792.655062]  [<ffffffffa039a69b>] btrfs_commit_transaction+0x228/0x654 [btrfs]
[ 9792.655064]  [<ffffffff8106e8da>] ? remove_wait_queue+0x3a/0x3a
[ 9792.655075]  [<ffffffffa03a2fa5>] btrfs_evict_inode+0x14d/0x202 [btrfs]
[ 9792.655077]  [<ffffffff81132bd6>] evict+0x71/0x111
[ 9792.655079]  [<ffffffff81132de0>] iput+0x12a/0x132
[ 9792.655081]  [<ffffffff8112aa3a>] do_unlinkat+0x106/0x155
[ 9792.655083]  [<ffffffff81127b83>] ? path_put+0x1f/0x23
[ 9792.655085]  [<ffffffff8109c53c>] ? audit_syscall_entry+0x145/0x171
[ 9792.655087]  [<ffffffff81128410>] ? putname+0x34/0x36
[ 9792.655090]  [<ffffffff8112b441>] sys_unlinkat+0x29/0x2b
[ 9792.655092]  [<ffffffff81482c42>] system_call_fastpath+0x16/0x1b
[ 9792.655093] ---[ end trace 02b696eb02b3f768 ]---

This patch fix it by setting the reservation of the transaction handle to the
correct one.
Reported-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Removes code no longer used. The sysfs file itself is kept, because the
btrfs developers expressed interest in putting new entries to sysfs.
Signed-off-by: NMaarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

smatch reports:

btrfs_recover_log_trees error: 'wc.replay_dest' dereferencing
possible ERR_PTR()
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Merge branch 'for-chris' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into for-linus

Conflicts:
	fs/btrfs/transaction.c
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The recent commit to get rid of our trans_mutex introduced
some races with block group relocation.  The problem is that relocation
needs to do some record keeping about each root, and it was relying
on the transaction mutex to coordinate things in subtle ways.

This fix adds a mutex just for the relocation code and makes sure
it doesn't have a big impact on normal operations.  The race is
really fixed in btrfs_record_root_in_trans, which is where we
step back and wait for the relocation code to finish accounting
setup.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

We can lockup if we try to allow new writers join the transaction and we have
flushoncommit set or have a pending snapshot.  This is because we set
no_trans_join and then loop around and try to wait for ordered extents again.
The problem is the ordered endio stuff needs to join the transaction, which it
can't do because no_trans_join is set.  So instead wait until after this loop to
set no_trans_join and then make sure to wait for num_writers == 1 in case
anybody got started in between us exiting the loop and setting no_trans_join.
This could easily be reproduced by mounting -o flushoncommit and running xfstest
13.  It cannot be reproduced with this patch.  Thanks,
Reported-by: NJim Schutt <jaschut@sandia.gov>
Signed-off-by: NJosef Bacik <josef@redhat.com>

Currently there is nothing protecting the pending_snapshots list on the
transaction.  We only hold the directory mutex that we are snapshotting and a
read lock on the subvol_sem, so we could race with somebody else creating a
snapshot in a different directory and end up with list corruption.  So protect
this list with the trans_lock.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

The delayed ref patch accidently removed the btrfs_free_path in
btrfs_unlink_subvol, this puts it back and means we don't leak a path.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

Even when delalloc_bytes is zero, we may need to sleep while waiting
for delalloc space.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Al Viro noticed we weren't checking for set_anon_super failures.  This
adds the required checks.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The WARN_ON() in start_transaction() was triggered while balancing.

The cause is btrfs_relocate_chunk() started a transaction and
then called iput() on the inode that stores free space cache,
and iput() called btrfs_start_transaction() again.
Reported-by: NTsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Get rid of FIXME comment.  Uuids from dmesg are now the same as uuids
given by btrfs-progs.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When encountering an EIO while reading from a nodatasum extent, we
insert an error record into the inode's failure tree.
btrfs_readpage_end_io_hook returns early for nodatasum inodes. We'd
better clear the failure tree in that case, otherwise the kernel
complains about

	BUG extent_state: Objects remaining on kmem_cache_close()

on rmmod.
Signed-off-by: NJan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Merge branch 'for-chris' of git://git.kernel.org/pub/scm/linux/kernel/git/arne/btrfs-unstable-arne into for-linus

list_splice_init will make delalloc_inodes empty, but without a spinlock
around, this may produce corrupted list head, accessed in many placess,
The race window is very tight and nobody seems to have hit it so far.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The size of struct btrfs_ioctl_fs_info_args is as big as 1KB, so
don't declare the variable on stack.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Reorder extent_buffer to remove 8 bytes of alignment padding on 64 bit
builds. This shrinks its size to 128 bytes allowing it to fit into one
fewer cache lines and allows more objects per slab in its kmem_cache.

slabinfo extent_buffer reports :-

 before:-
    Sizes (bytes)     Slabs
    ----------------------------------
    Object :     136  Total  :     123
    SlabObj:     136  Full   :     121
    SlabSiz:    4096  Partial:       0
    Loss   :       0  CpuSlab:       2
    Align  :       8  Objects:      30

 after :-
    Object :     128  Total  :       4
    SlabObj:     128  Full   :       2
    SlabSiz:    4096  Partial:       0
    Loss   :       0  CpuSlab:       2
    Align  :       8  Objects:      32
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Normally current->jouranl_info is cleared by commit_transaction.  For an
async snap or subvol creation, though, it runs in a work queue.  Clear
it in btrfs_commit_transaction_async() to avoid leaking a non-NULL
journal_info when we return to userspace.  When the actual commit runs in
the other thread it won't care that it's current->journal_info is already
NULL.
Signed-off-by: NSage Weil <sage@newdream.net>
Tested-by: NJim Schutt <jaschut@sandia.gov>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Josef recently changed the free extent cache to look in
the block group cluster for any bitmaps before trying to
add a new bitmap for the same offset.  This avoids BUG_ON()s due
covering duplicate ranges.

But it didn't go quite far enough.  A given free range might span
between one or more bitmaps or free space entries.  The code has
looping to cover this, but it doesn't check for clustered bitmaps
every time.

This shuffles our gotos to check for a bitmap in the cluster
for every new bitmap entry we try to add.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NArne Jansen <sensille@gmx.net>

Scrub starts the workers each time a scrub starts and stops them after it
finished. This patch adds an initialization for the workers before each
start, otherwise the workers behave strangely.
Signed-off-by: NArne Jansen <sensille@gmx.net>

due to the semantics of btrfs_search_slot the path can point to an
invalid slot when ret > 0. This condition went unnoticed, which in
turn could have led to an incomplete scrubbing.
Signed-off-by: NArne Jansen <sensille@gmx.net>

Arne's scrub stuff exposed a problem with mapping the extent buffer in
reada_for_search.  He searches the commit root with multiple threads and with
skip_locking set, so we can race and overwrite node->map_token since node isn't
locked.  So fix this so that we only map the extent buffer if we don't already
have a map_token and skip_locking isn't set.  Without this patch scrub would
panic almost immediately, with the patch it doesn't panic anymore.  Thanks,
Reported-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NJosef Bacik <josef@redhat.com>

In btrfs_wait_for_commit if we came upon a transaction that had committed we
just exited, but that's bad since we are holding the trans_lock.  So break
instead so that the lock is dropped.  Thanks,
Reported-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NJosef Bacik <josef@redhat.com>

Arne's scrub stuff exposed a problem with mapping the extent buffer in
reada_for_search.  He searches the commit root with multiple threads and with
skip_locking set, so we can race and overwrite node->map_token since node isn't
locked.  So fix this so that we only map the extent buffer if we don't already
have a map_token and skip_locking isn't set.  Without this patch scrub would
panic almost immediately, with the patch it doesn't panic anymore.  Thanks,
Reported-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NJosef Bacik <josef@redhat.com>

When merging my code into the integration test the second check for duplicate
entries got screwed up.  This patch fixes it by dropping ret2 and just using ret
for the return value, and checking if we got an error before adding the bitmap
to the local list.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

I was testing with empty_cluster = 0 to try and reproduce a problem and kept
hitting early enospc panics.  This was because our loop logic was a little
confused.  So this is what I did

1) Make the loop variable the ultimate decider on wether we should loop again
isntead of checking to see if we had an uncached bg, empty size or empty
cluster.

2) Increment loop before checking to see what we are on to make the loop
definitions make more sense.

3) If we are on the chunk alloc loop don't set empty_size/empty_cluster to 0
unless we didn't actually allocate a chunk.  If we did allocate a chunk we
should be able to easily setup a new cluster so clearing
empty_size/empty_cluster makes us less efficient.

This kept me from hitting panics while trying to reproduce the other problem.
Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

In cleaning up the clustering code I accidently introduced a regression by
adding bitmap entries to the cluster rb tree.  The problem is if we've maxed out
the number of bitmaps we can have for the block group we can only add free space
to the bitmaps, but since the bitmap is on the cluster we can't find it and we
try to create another one.  This would result in a panic because the total
bitmaps was bigger than the max bitmaps that were allowed.  This patch fixes
this by checking to see if we have a cluster, and then looking at the cluster rb
tree to see if it has a bitmap entry and if it does and that space belongs to
that bitmap, go ahead and add it to that bitmap.

I could hit this panic every time with an fs_mark test within a couple of
minutes.  With this patch I no longer hit the panic and fs_mark goes to
completion.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

I noticed when running an enospc test that we would get stuck committing the
transaction in check_data_space even though we truly didn't have enough space.
So check to see if bytes_pinned is bigger than num_bytes, if it's not don't
commit the transaction.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

When profiling the find cluster code it's hard to tell where we are spending our
time because the bitmap and non-bitmap functions get inlined by the compiler, so
make that not happen.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

If we are looking for a cluster in a particularly sparse or fragmented block
group, we will do a lot of looping through the free space tree looking for
various things, and if we need to look at bitmaps we will endup doing the whole
dance twice.  So instead add the bitmap entries to a temporary list so if we
have to do the bitmap search we can just look through the list of entries we've
found quickly instead of having to loop through the entire tree again.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>

With Linus' tree, today's linux-next build (powercp ppc64_defconfig)
produced this warning:

fs/btrfs/delayed-inode.c: In function 'btrfs_delayed_update_inode':
fs/btrfs/delayed-inode.c:1598:6: warning: 'ret' may be used
uninitialized in this function

Introduced by commit 16cdcec7 ("btrfs: implement delayed inode items
operation").

This fixes a bug in btrfs_update_inode(): if the returned value from
btrfs_delayed_update_inode is a nonzero garbage, inode stat data are not
updated and several call paths may hit a BUG_ON or fail with strange
code.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

wrap checking of filesystem 'closing' flag and fix a few missing memory
barriers.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>

This makes the inode map cache default to off until we
fix the overflow problem when the free space crcs don't fit
inside a single page.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

With the removal of the implicit plugging scrub ends up doing more and
smaller I/O than necessary. This patch adds explicit plugging per chunk.
Signed-off-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

commit 4cb5300b ("Btrfs: add mount -o auto_defrag") accesses inode
number directly while it should use the helper with the new inode
number allocator.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

With xfstest 254 I can panic the box every time with the inode number caching
stuff on.  This is because we clean the inodes out when we delete the subvolume,
but then we write out the inode cache which adds an inode to the subvolume inode
tree, and then when it gets evicted again the root gets added back on the dead
roots list and is deleted again, so we have a double free.  To stop this from
happening just return 0 if refs is 0 (and we're not the tree root since tree
root always has refs of 0).  With this fix 254 no longer panics.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Tested-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

In degraded mode the struct btrfs_device of missing devs don't have
device->name set. A kstrdup of NULL correctly returns NULL. Don't
BUG in this case.
Signed-off-by: NArne Jansen <sensille@gmx.net>
Signed-off-by: NChris Mason <chris.mason@oracle.com>