Commit Graph

5561 Commits

Author SHA1 Message Date
Jeff Mahoney
bd6c57dda6 btrfs: simpilify btrfs_subvol_inherit_props
We just need a superblock, but we look it up using two different
roots depending on the call site.  Let's just use a superblock
pointer initialized at the outset.

This is mostly for Coccinelle not to choke on my root push up set.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:54:22 +02:00
Jeff Mahoney
f5ee5c9ac5 btrfs: tests, use BTRFS_FS_STATE_DUMMY_FS_INFO instead of dummy root
Now that we have a dummy fs_info associated with each test that
uses a root, we don't need the DUMMY_ROOT bit anymore.  This lets
us make choices without needing an actual root like in e.g.
btrfs_find_create_tree_block.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:54:19 +02:00
Jeff Mahoney
7c0260ee09 btrfs: tests, require fs_info for root
This allows the upcoming patchset to push nodesize and sectorsize into
fs_info.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:53:18 +02:00
Jeff Mahoney
8632daae40 btrfs: tests, move initialization into tests/
We have all these stubs that only exist because they're called from
btrfs_run_sanity_tests, which is a static inside super.c.  Let's just
move it all into tests/btrfs-tests.c and only have one stub.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:53:17 +02:00
Jeff Mahoney
3cdde2240d btrfs: btrfs_test_opt and friends should take a btrfs_fs_info
btrfs_test_opt and friends only use the root pointer to access
the fs_info.  Let's pass the fs_info directly in preparation to
eliminate similar patterns all over btrfs.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:53:16 +02:00
Jeff Mahoney
bc074524e1 btrfs: prefix fsid to all trace events
When using trace events to debug a problem, it's impossible to determine
which file system generated a particular event.  This patch adds a
macro to prefix standard information to the head of a trace event.

The extent_state alloc/free events are all that's left without an
fs_info available.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:53:16 +02:00
Jeff Mahoney
cb001095ca btrfs: plumb fs_info into btrfs_work
In order to provide an fsid for trace events, we'll need a btrfs_fs_info
pointer.  The most lightweight way to do that for btrfs_work structures
is to associate it with the __btrfs_workqueue structure.  Each queued
btrfs_work structure has a workqueue associated with it, so that's
a natural fit.  It's a privately defined structures, so we add accessors
to retrieve the fs_info pointer.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:53:15 +02:00
David Sterba
9f8d49095b btrfs: remove obsolete part of comment in statfs
The mixed blockgroup reporting has been fixed by commit
ae02d1bd07
"btrfs: fix mixed block count of available space"

Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
David Sterba
05653ef386 btrfs: hide test-only member under ifdef
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Nikolay Borisov
aee133afcd btrfs: Ratelimit "no csum found" info message
Recently during a crash it became apparent that this particular message
can be printed so many times that it causes the softlockup detector to
trigger. Fix it by ratelimiting it.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Nikolay Borisov
35f4e5e6f1 btrfs: Add ratelimit to btrfs printing
This patch adds ratelimiting to all messages which are not using the _rl
version of the various printing APIs in btrfs. This is designed to be
used as a safety net, since a flood messages might cause the softlockup
detector to trigger. To reduce interference between different classes of
messages use a separate ratelimit state for every class of message.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
5a488b9d2c Btrfs: fix unexpected balance crash due to BUG_ON
Mounting a btrfs can resume previous balance operations asynchronously.
An user got a crash when one drive has some corrupt sectors.

Since balance can cancel itself in case of any error, we can gracefully
return errors to upper layers and let balance do the cancel job.

Reported-by: sash <master.b.at.raven@chefmail.de>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
0fd8c3dae1 Btrfs: fix panic in balance due to EIO
During build_backref_tree(), if we fail to read a btree node,
we can eventually run into BUG_ON(cache->nr_nodes) that we put
in backref_cache_cleanup(), meaning we have at least one
memory leak.

This frees the backref_node that we's allocated at the very
beginning of build_backref_tree().

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
baf863b9c2 Btrfs: fix eb memory leak due to readpage failure
eb->io_pages is set in read_extent_buffer_pages().

In case of readpage failure, for pages that have been added to bio,
it calls bio_endio and later readpage_io_failed_hook() does the work.

When this eb's page (couldn't be the 1st page) fails to add itself to bio
due to failure in merge_bio(), it cannot decrease eb->io_pages via bio_endio,
 and ends up with a memory leak eventually.

This lets __do_readpage propagate errors to callers and adds the
 'atomic_dec(&eb->io_pages)'.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
f49070957f Btrfs: change BUG_ON()'s to ASSERT()'s in backref_cache_cleanup()
Since it is just an in-memory building of the backrefs of several
btree blocks, nothing is fatal other than memory leaks, so this
changes BUG_ON()'s to ASSERT()'s.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Wang Xiaoguang
39581a3a1a btrfs: fix free space calculation in dump_space_info()
In btrfs, btrfs_space_info's bytes_may_use is treated as fs used
space, as what we do in reserve_metadata_bytes() or
btrfs_alloc_data_chunk_ondemand(), so in dump_space_info(), when
calculating free space, we should also subtract btrfs_space_info's
bytes_may_use.

Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Chandan Rajendra
751bebbe0a Btrfs: subpage-blocksize: Rate limit scrub error message
btrfs/073 invokes scrub ioctl in a tight loop. In subpage-blocksize
scenario this results in a lot of "scrub: size assumption sectorsize !=
PAGE_SIZE " messages being printed on the console. To reduce the number
of such messages this commit uses btrfs_err_rl() instead of
btrfs_err().

Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Wang Xiaoguang
dda3245eca btrfs: expand cow_file_range() to support in-band dedup and subpage-blocksize
Extract cow_file_range() new parameters for both in-band dedupe and
subpage sector size patchset.

This should make conflict of both patchset to minimal, and reduce the
effort needed to rebase them.

Cc: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
f5daf2c780 Btrfs: fix BUG_ON in btrfs_submit_compressed_write
This is similar to btrfs_submit_compressed_read(), if we fail after
bio is allocated, then we can use bio_endio() and errors are saved
 in bio->bi_error.  But please note that we don't return errors to
its caller because the caller assumes it won't call endio to cleanup
on error.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Anand Jain
e2bf6e89b4 btrfs: make sure device is synced before return
An inconsistent behavior due to stale reads from the
disk was reported

  mail-archive.com/linux-btrfs@vger.kernel.org/msg54188.html

This patch will make sure devices are synced before
return in the unmount thread.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Anand Jain
f448341af9 btrfs: reorg btrfs_close_one_device()
Moves closer to the caller and removes declaration

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Ashish Samant
c8bb0c8bd2 btrfs: Cleanup compress_file_range()
Remove unnecessary checks in compress_file_range().

Signed-off-by: Ashish Samant <ashish.samant@oracle.com>
[ minor coding style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
6f034ece34 Btrfs: cleanup BUG_ON in merge_bio
One can use btrfs-corrupt-block to hit BUG_ON() in merge_bio(),
thus this aims to stop anyone to panic the whole system by using
 their btrfs.

Since the error in merge_bio can only come from __btrfs_map_block()
when chunk tree mapping has something insane and __btrfs_map_block()
has already had printed the reason, we can just return errors in
merge_bio.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Nikolay Borisov
fba4b69771 btrfs: Fix slab accounting flags
BTRFS is using a variety of slab caches to satisfy internal needs.
Those slab caches are always allocated with the SLAB_RECLAIM_ACCOUNT,
meaning allocations from the caches are going to be accounted as
SReclaimable. At the same time btrfs is not registering any shrinkers
whatsoever, thus preventing memory from the slabs to be shrunk. This
means those caches are not in fact reclaimable.

To fix this remove the SLAB_RECLAIM_ACCOUNT on all caches apart from the
inode cache, since this one is being freed by the generic VFS super_block
shrinker. Also set the transaction related caches as SLAB_TEMPORARY,
to better document the lifetime of the objects (it just translates
to SLAB_RECLAIM_ACCOUNT).

Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Salah Triki
a60617d0ae btrfs: Replace -ENOENT by -ERANGE in btrfs_get_acl()
size contains the value returned by posix_acl_from_xattr(), which
returns -ERANGE, -ENODATA, zero, or an integer greater than zero. So
replace -ENOENT by -ERANGE.

Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Nikolay Borisov
3d48d9810d btrfs: Handle uninitialised inode eviction
The code flow in btrfs_new_inode allows for btrfs_evict_inode to be
called with not fully initialised inode (e.g. ->root member not
being set). This can happen when btrfs_set_inode_index in
btrfs_new_inode fails, which in turn would call iput for the newly
allocated inode. This in turn leads to vfs calling into btrfs_evict_inode.
This leads to null pointer dereference. To handle this situation check whether
the passed inode has root set and just free it in case it doesn't.

Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
fb770ae414 Btrfs: fix read_node_slot to return errors
We use read_node_slot() to read btree node and it has two cases,
a) slot is out of range, which means 'no such entry'
b) we fail to read the block, due to checksum fails or corrupted
   content or not with uptodate flag.
But we're returning NULL in both cases, this makes it return -ENOENT
in case a) and return -EIO in case b), and this fixes its callers
as well as btrfs_search_forward() 's caller to catch the new errors.

The problem is reported by Peter Becker, and I can manage to
hit the same BUG_ON by mounting my fuzz image.

Reported-by: Peter Becker <floyd.net@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
876d2cf141 Btrfs: fix double free of fs root
I got this warning while mounting a btrfs image,

[ 3020.509606] ------------[ cut here ]------------
[ 3020.510107] WARNING: CPU: 3 PID: 5581 at lib/idr.c:1051 ida_remove+0xca/0x190
[ 3020.510853] ida_remove called for id=42 which is not allocated.
[ 3020.511466] Modules linked in:
[ 3020.511802] CPU: 3 PID: 5581 Comm: mount Not tainted 4.7.0-rc5+ #274
[ 3020.512438] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014
[ 3020.513385]  0000000000000286 0000000021295d86 ffff88006c66b8f0 ffffffff8182ba5a
[ 3020.514153]  0000000000000000 0000000000000009 ffff88006c66b930 ffffffff810e0ed7
[ 3020.514928]  0000041b00000000 ffffffff8289a8c0 ffff88007f437880 0000000000000000
[ 3020.515717] Call Trace:
[ 3020.515965]  [<ffffffff8182ba5a>] dump_stack+0xc9/0x13f
[ 3020.516487]  [<ffffffff810e0ed7>] __warn+0x147/0x160
[ 3020.517005]  [<ffffffff810e0f4f>] warn_slowpath_fmt+0x5f/0x80
[ 3020.517572]  [<ffffffff8182e6ca>] ida_remove+0xca/0x190
[ 3020.518075]  [<ffffffff813a2bcc>] free_anon_bdev+0x2c/0x60
[ 3020.518609]  [<ffffffff81657a9f>] free_fs_root+0x13f/0x160
[ 3020.519138]  [<ffffffff8165c679>] btrfs_get_fs_root+0x379/0x3d0
[ 3020.519710]  [<ffffffff81e6e975>] ? __mutex_unlock_slowpath+0x155/0x2c0
[ 3020.520366]  [<ffffffff816615b1>] open_ctree+0x2e91/0x3200
[ 3020.520965]  [<ffffffff8161ede2>] btrfs_mount+0x1322/0x15b0
[ 3020.521536]  [<ffffffff81e60e74>] ? kmemleak_alloc_percpu+0x44/0x170
[ 3020.522167]  [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210
[ 3020.522780]  [<ffffffff813a4f59>] mount_fs+0x49/0x2c0
[ 3020.523305]  [<ffffffff813d840c>] vfs_kern_mount+0xac/0x1b0
[ 3020.523872]  [<ffffffff8161dee1>] btrfs_mount+0x421/0x15b0
[ 3020.524402]  [<ffffffff81e60e74>] ? kmemleak_alloc_percpu+0x44/0x170
[ 3020.525045]  [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210
[ 3020.525657]  [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210
[ 3020.526289]  [<ffffffff813a4f59>] mount_fs+0x49/0x2c0
[ 3020.526803]  [<ffffffff813d840c>] vfs_kern_mount+0xac/0x1b0
[ 3020.527365]  [<ffffffff813dc27a>] do_mount+0x41a/0x1770
[ 3020.527899]  [<ffffffff812e800d>] ? strndup_user+0x6d/0xc0
[ 3020.528447]  [<ffffffff812e7f68>] ? memdup_user+0x78/0xb0
[ 3020.528987]  [<ffffffff813ddad0>] SyS_mount+0x150/0x160
[ 3020.529493]  [<ffffffff81e72b7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd

It turns out that we free fs root twice, btrfs_init_fs_root() calls
free_anon_bdev(root->anon_dev) and later then btrfs_get_fs_root() cals
free_fs_root which does another free_anon_bdev() and it ends up with the
above warning.

Instead of reset root->anon_dev to 0 after free_anon_bdev(), we can let
btrfs_init_fs_root() return directly since its callers have already done
the free job by calling free_fs_root().

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
5e24e9af01 Btrfs: error out if generic_bin_search get invalid arguments
With btrfs-corrupt-block, one can set btree node/leaf's field, if
we assign a negative value to node/leaf, we can get various hangs,
eg. if extent_root's nritems is -2ULL, then we get stuck in
 btrfs_read_block_groups() because it has a while loop and
btrfs_search_slot() on extent_root will always return the first
 child.

This lets us know what's happening and returns a EINVAL to callers
instead of returning the first item.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Liu Bo
6fb37b756a Btrfs: check inconsistence between chunk and block group
With btrfs-corrupt-block, one can drop one chunk item and mounting
will end up with a panic in btrfs_full_stripe_len().

This doesn't not remove the BUG_ON, but instead checks it a bit
earlier when we find the block group item.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Wang Xiaoguang
c1fd5c30d1 btrfs: add missing bytes_readonly attribute file in sysfs
Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26 13:52:25 +02:00
Chris Mason
8b8b08cbfb Btrfs: fix delalloc accounting after copy_from_user faults
Commit 56244ef151 was almost but not quite enough to fix the
reservation math after btrfs_copy_from_user returned partial copies.

Some users are still seeing warnings in btrfs_destroy_inode, and with a
long enough test run I'm able to trigger them as well.

This patch fixes the accounting math again, bringing it much closer to
the way it was before the sectorsize conversion Chandan did.  The
problem is accounting for the offset into the page/sector when we do a
partial copy.  This one just uses the dirty_sectors variable which
should already be updated properly.

Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org # v4.6+
2016-07-21 04:03:40 -07:00
Josef Bacik
bac357dcec Btrfs: avoid deadlocks during reservations in btrfs_truncate_block
The new enospc code makes it possible to deadlock if we don't use
FLUSH_LIMIT during reservations inside a transaction.  This enforces
the correct flush type to avoid both deadlocks and assertions

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
2016-07-20 16:58:04 -07:00
Josef Bacik
8ca17f0f59 Btrfs: use FLUSH_LIMIT for relocation in reserve_metadata_bytes
We used to allow you to set FLUSH_ALL and then just wouldn't do things like
commit transactions or wait on ordered extents if we noticed you were in a
transaction.  However now that all the flushing for FLUSH_ALL is asynchronous
we've lost the ability to tell, and we could end up deadlocking.  So instead use
FLUSH_LIMIT in reserve_metadata_bytes in relocation and then return -EAGAIN if
we error out to preserve the previous behavior.  I've also added an ASSERT() to
catch anybody else who tries to do this.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
ac2fabac42 Btrfs: fill relocation block rsv after allocation
Since we set the reloc control before we've reserved our space for relocation we
could race with a root being dirtied and not actually have space to do our init
reloc root.  So once we've allocated it and set it up go ahead and make our
reservation before setting the relocate control, that way anybody who tries to
do the reloc root init has space to use.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
40acc3eede Btrfs: always use trans->block_rsv for orphans
This is the case all the time anyway except for relocation which could be doing
a reloc root for a non ref counted root, in which case we'd end up with some
random block rsv rather than the one we have our reservation in.  If there isn't
enough space in the block rsv we are trying to steal from we'll BUG() because we
expect there to be space for the orphan to make its reservation.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
ae2e472881 Btrfs: change how we calculate the global block rsv
Traditionally we've calculated the global block rsv by guessing how much of the
metadata used amount was the extent tree, and then taking the data size and
figuring out how large the csum tree would have to be to hold that much data.

This is imprecise and falls down on MIXED file systems as we can't trust the
data used amount.  This resulted in failures for xfstests generic/333 because it
creates lots of clones, which explodes out the extent tree.  Our global reserve
calculations were woefully inaccurate in this case which meant we got into a
situation where we did not have enough reserved to do our work.

We know we only use the global block rsv for the extent, csum, and root trees,
so just get the bytes used for these trees and use that as the basis of our
global reserve.  Since these are not reference counted trees the bytes_used
value will be accurate.  This fixed the transaction aborts seen with
generic/333.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
87241c2e68 Btrfs: use root when checking need_async_flush
Instead of doing fs_info->fs_root in need_async_flush, which may not be set
during recovery when mounting, just pass the root itself in, which makes more
sense as thats what btrfs_calc_reclaim_metadata_size takes.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reported-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
d38b349c39 Btrfs: don't bother kicking async if there's nothing to reclaim
We do this check when we start the async reclaimer thread, might as well check
before we kick it off to save us some cycles.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
31bada7c4e Btrfs: fix release reserved extents trace points
We were doing trace_btrfs_release_reserved_extent() in pin_down_extent which
isn't quite right because we will go through and free that extent later when we
unpin, so it messes up apps that are accounting for the reservation space.  We
were also unconditionally doing it in __btrfs_free_reserved_extent(), when we
only actually free the reservation instead of pinning the extent.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
f376df2b7d Btrfs: add tracepoints for flush events
We want to track when we're triggering flushing from our reservation code and
what flushing is being done when we start flushing.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
f485c9ee32 Btrfs: fix delalloc reservation amount tracepoint
We can sometimes drop the reservation we had for our inode, so we need to remove
that amount from to_reserve so that our tracepoint reports a valid amount of
space.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
c51e7bb184 Btrfs: trace pinned extents
Pinned extents are an important metric to keep track of for enospc.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
957780eb27 Btrfs: introduce ticketed enospc infrastructure
Our enospc flushing sucks.  It is born from a time where we were early
enospc'ing constantly because multiple threads would race in for the same
reservation and randomly starve other ones out.  So I came up with this solution
to block any other reservations from happening while one guy tried to flush
stuff to satisfy his reservation.  This gives us pretty good correctness, but
completely crap latency.

The solution I've come up with is ticketed reservations.  Basically we try to
make our reservation, and if we can't we put a ticket on a list in order and
kick off an async flusher thread.  This async flusher thread does the same old
flushing we always did, just asynchronously.  As space is freed and added back
to the space_info it checks and sees if we have any tickets that need
satisfying, and adds space to the tickets and wakes up anything we've satisfied.

Once the flusher thread stops making progress it wakes up all the current
tickets and tells them to take a hike.

There is a priority list for things that can't flush, since the async flusher
could do anything we need to avoid deadlocks.  These guys get priority for
having their reservation made, and will still do manual flushing themselves in
case the async flusher isn't running.

This patch gives us significantly better latencies.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
c83f8effef Btrfs: add tracepoint for adding block groups
I'm writing a tool to visualize the enospc system inside btrfs, I need this
tracepoint in order to keep track of the block groups in the system.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
d555b6c380 Btrfs: warn_on for unaccounted spaces
These were hidden behind enospc_debug, which isn't helpful as they indicate
actual bugs, unlike the rest of the enospc_debug stuff which is really debug
information.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
c48f49d63d Btrfs: change delayed reservation fallback behavior
We reserve space for the inode update when we first reserve space for writing to
a file.  However there are lots of ways that we can use this reservation and not
have it for subsequent ordered extents.  Previously we'd fall through and try to
reserve metadata bytes for this, then we'd just steal the full reservation from
the delalloc_block_rsv, and if that didn't have enough space we'd steal the full
reservation from the global reserve.  The problem with this is we can easily
just return ENOSPC and fallback to updating the inode item directly.  In the
worst case (assuming 4k nodesize) we'd steal 64kib from the global reserve if we
fall all the way through, however if we just fallback and update the inode
directly we'd only steal 4k * BTRFS_PATH_MAX in the worst case which is 32kib.

We would have also just added the extent item for the inode so we likely will
have already cow'ed down most of the way to the leaf containing the inode item,
so we are more often than not only need one or two nodesize's worth of
reservations.  Given the reservation for the extent itself is also a worst case
we will likely already have space to cover the inode update.

This change will make us behave better in the theoretical worst case, and much
better in the case that we don't have our reservation and cannot reserve more
metadata.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
48c3d480e4 Btrfs: always reserve metadata for delalloc extents
There are a few races in the metadata reservation stuff.  First we add the bytes
to the block_rsv well after we've set the bit on the inode saying that we have
space for it and after we've reserved the bytes.  So use the normal
btrfs_block_rsv_add helper for this case.  Secondly we can flush delalloc
extents when we try to reserve space for our write, which means that we could
have used up the space for the inode and we wouldn't know because we only check
before the reservation.  So instead make sure we are always reserving space for
the inode update, and then if we don't need it release those bytes afterward.
Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
25d609f86d Btrfs: fix callers of btrfs_block_rsv_migrate
So btrfs_block_rsv_migrate just unconditionally calls block_rsv_migrate_bytes.
Not only this but it unconditionally changes the size of the block_rsv.  This
isn't a bug strictly speaking, but it makes truncate block rsv's look funny
because every time we migrate bytes over its size grows, even though we only
want it to be a specific size.  So collapse this into one function that takes an
update_size argument and make truncate and evict not update the size for
consistency sake.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00
Josef Bacik
e40edf2da4 Btrfs: add bytes_readonly to the spaceinfo at once
For some reason we're adding bytes_readonly to the space info after we update
the space info with the block group info.  This creates a tiny race where we
could over-reserve space because we haven't yet taken out the bytes_readonly
bit.  Since we already know this information at the time we call
update_space_info, just pass it along so it can be updated all at once.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-07 18:45:53 +02:00