Daniel J Blueman [Thu, 23 Jun 2011 15:01:01 +0000 (23:01 +0800)]
btrfs: fix oops on failure path
If lookup_extent_backref fails, path->nodes[0] reasonably could be
null along with other callers of btrfs_print_leaf, so ensure we have a
valid extent buffer before dereferencing.
Btrfs: fix race between multi-task space allocation and caching space
The task may fail to get free space though it is enough when multi-task
space allocation and caching space happen at the same time.
Task1 Caching Thread Task2
------------------------------------------------------------------------
find_free_extent
The space has not
be cached, and start
caching thread. And
wait for it.
cache space, if
the space is > 2MB
wake up Task1
find_free_extent
get all the space that
is cached.
try to allocate space,
but there is no space
now.
trigger BUG_ON()
The message is following:
btrfs allocation failed flags 1, wanted 4096
space_info has 1040187392 free, is not full
space_info total=1082130432, used=4096, pinned=41938944, reserved=0, may_use=40828928, readonly=0
block group 12582912 has 8388608 bytes, 0 used 8388608 pinned 0 reserved
block group has cluster?: no
0 blocks of free space at or bigger than bytes is
block group 1103101952 has 1073741824 bytes, 4096 used 33550336 pinned 0 reserved
block group has cluster?: no
0 blocks of free space at or bigger than bytes is
------------[ cut here ]------------
kernel BUG at fs/btrfs/inode.c:835!
[<ffffffffa031261b>] __extent_writepage+0x1bf/0x5ce [btrfs]
[<ffffffff810cbcb8>] ? __set_page_dirty_nobuffers+0xfe/0x108
[<ffffffffa02f8ada>] ? wait_current_trans+0x23/0xec [btrfs]
[<ffffffff810c3fbf>] ? find_get_pages_tag+0x73/0xe2
[<ffffffffa0312d12>] extent_write_cache_pages.clone.0+0x176/0x29a [btrfs]
[<ffffffffa0312e74>] extent_writepages+0x3e/0x53 [btrfs]
[<ffffffff8110ad2c>] ? do_sync_write+0xc6/0x103
[<ffffffffa0302d6e>] ? btrfs_submit_direct+0x414/0x414 [btrfs]
[<ffffffff811380fa>] ? fsnotify+0x236/0x266
[<ffffffffa02fc930>] btrfs_writepages+0x22/0x24 [btrfs]
[<ffffffff810cc215>] do_writepages+0x1c/0x25
[<ffffffff810c4958>] __filemap_fdatawrite_range+0x4e/0x50
[<ffffffff810c4982>] filemap_write_and_wait_range+0x28/0x51
[<ffffffffa0306b2e>] btrfs_sync_file+0x7d/0x198 [btrfs]
[<ffffffff8110aa26>] ? fsnotify_modify+0x5d/0x65
[<ffffffff8112d150>] vfs_fsync_range+0x18/0x21
[<ffffffff8112d170>] vfs_fsync+0x17/0x19
[<ffffffff8112d316>] do_fsync+0x29/0x3e
[<ffffffff8112d348>] sys_fsync+0xb/0xf
[<ffffffff81468352>] system_call_fastpath+0x16/0x1b
[SNIP]
RIP [<ffffffffa02fe08c>] cow_file_range+0x1c4/0x32b [btrfs]
We fix this bug by trying to allocate the space again if there are block groups
in caching.
Ilya Dryomov [Sun, 2 Oct 2011 10:56:53 +0000 (13:56 +0300)]
Btrfs: pass the correct root to lookup_free_space_inode()
Free space items are located in tree of tree roots, not in the extent
tree. It didn't pop up because lookup_free_space_inode() grabs the
inode all the time instead of actually searching the tree.
btrfs: return EINVAL if start > total_bytes in fitrim ioctl
We should retirn EINVAL if the start is beyond the end of the file
system in the btrfs_ioctl_fitrim(). Fix that by adding the appropriate
check for it.
Also in the btrfs_trim_fs() it is possible that len+start might overflow
if big values are passed. Fix it by decrementing the len so that start+len
is equal to the file system size in the worst case.
Li Zefan [Fri, 2 Sep 2011 07:57:07 +0000 (15:57 +0800)]
Btrfs: honor extent thresh during defragmentation
We won't defrag an extent, if it's bigger than the threshold we
specified and there's no small extent before it, but actually
the code doesn't work this way.
There are three bugs:
- When should_defrag_range() decides we should keep on defragmenting
an extent, last_len is not incremented. (old bug)
- The length that passes to should_defrag_range() is not the length
we're going to defrag. (new bug)
- We always defrag 256K bytes data, and a big extent can be part of
this range. (new bug)
For a file with 4 extents:
| 4K | 4K | 256K | 256K |
The result of defrag with (the default) 256K extent thresh should be:
Yan, Zheng [Mon, 29 Aug 2011 01:25:53 +0000 (09:25 +0800)]
btrfs: check file extent backref offset underflow
Offset field in data extent backref can underflow if clone range ioctl
is used. We can reliably detect the underflow because max file size is
limited to 2^63 and max data extent size is limited by block group size.
Josef Bacik [Wed, 19 Oct 2011 14:31:37 +0000 (10:31 -0400)]
Btrfs: don't flush the cache inode before writing it
I noticed we had a little bit of latency when writing out the space cache
inodes. It's because we flush it before we write anything in case we have dirty
pages already there. This doesn't matter though since we're just going to
overwrite the space, and there really shouldn't be any dirty pages anyway. This
makes some of my tests run a little bit faster. Thanks,
Josef Bacik [Tue, 18 Oct 2011 17:07:31 +0000 (13:07 -0400)]
Btrfs: if we have a lot of pinned space, commit the transaction
Mitch kept hitting a panic because he was getting ENOSPC. One of my previous
patches makes it so we are much better at not allocating new metadata chunks.
Unfortunately coupled with the overcommit patch this works us into a bit of a
problem if we are removing a bunch of space and end up chewing up all of our
space with pinned extents. We can allocate chunks fine and overflow is ok, but
the only way to reclaim this space is to commit the transaction. So if we go to
overcommit, first check and see how much pinned space we have. If we have more
than 80% of the free space chewed up with pinned extents, just commit the
transaction, this will free up enough space for our reservation and we won't
have this problem anymore. With this patch Mitch's test doesn't blow up
anymore. Thanks,
Reported-and-tested-by: Mitch Harder <mitch.harder@sabayonlinux.org> Signed-off-by: Josef Bacik <josef@redhat.com>
(cherry picked from commit 7e355b83efa80e5f5821591c13c17649594d82ac)
Josef Bacik [Tue, 18 Oct 2011 16:15:48 +0000 (12:15 -0400)]
Btrfs: seperate out btrfs_block_rsv_check out into 2 different functions
Currently btrfs_block_rsv_check does 2 things, it will either refill a block
reserve like in the truncate or refill case, or it will check to see if there is
enough space in the global reserve and possibly refill it. However because of
overcommit we could be well overcommitting ourselves just to try and refill the
global reserve, when really we should just be committing the transaction. So
breack this out into btrfs_block_rsv_refill and btrfs_block_rsv_check. Refill
will try to reserve more metadata if it can and btrfs_block_rsv_check will not,
it will only tell you if the factor of the total space is still reserved.
Thanks,
Josef Bacik [Fri, 14 Oct 2011 18:46:51 +0000 (14:46 -0400)]
Btrfs: reserve some space for an orphan item when unlinking
In __unlink_start_trans() if we don't have enough room for a reservation we will
check to see if the unlink will free up space. If it does that's great, but we
will still could add an orphan item, so we need to reserve enough space to add
the orphan item. Do this and migrate the space the global reserve so it all
works out right. Thanks,
Josef Bacik [Fri, 14 Oct 2011 18:40:17 +0000 (14:40 -0400)]
Btrfs: release trans metadata bytes before flushing delayed refs
We started setting trans->block_rsv = NULL to allow the delayed refs flushing
stuff to use the right block_rsv and then just made
btrfs_trans_release_metadata() unconditionally use the trans block rsv. The
problem with this is we need to reserve some space in the transaction and then
migrate it to the global block rsv, so we need to be able to free that out
properly. So instead just move btrfs_trans_release_metadata() before the
delayed ref flushing and use trans->block_rsv for the freeing. Thanks,
Josef Bacik [Fri, 14 Oct 2011 18:02:10 +0000 (14:02 -0400)]
Btrfs: allow shrink_delalloc flush the needed reclaimed pages
Currently we only allow a maximum of 2 megabytes of pages to be flushed at a
time. This was ok before, but now we have overcommit which will screw us in a
heartbeat if we are quickly filling the disk. So instead pick either 2
megabytes or the number of pages we need to reclaim to be safe again, which ever
is larger. Thanks,
Josef Bacik [Fri, 14 Oct 2011 17:56:58 +0000 (13:56 -0400)]
Btrfs: wait for ordered extents if we're in trouble when shrinking delalloc
The only way we actually reclaim delalloc space is waiting for the IO to
completely finish. Usually we kick off a bunch of IO and wait for a little bit
and hope we can make our reservation, and usually this works out pretty well.
With overcommit however we can get seriously underwater if we're filling up the
disk quickly, so we need to be able to force the delalloc shrinker to wait for
the ordered IO to finish to give us a better chance of actually reclaiming
enough space to get our reservation. Thanks,
Josef Bacik [Fri, 14 Oct 2011 17:37:45 +0000 (13:37 -0400)]
Btrfs: don't check bytes_pinned to determine if we should commit the transaction
Before the only reason to commit the transaction to recover space in
reserve_metadata_bytes() was if there were enough pinned_bytes to satisfy our
reservation. But now we have the delayed inode stuff which will hold it's
reservations until we commit the transaction. So say we max out our reservation
by creating a bunch of files but don't have any pinned bytes we will ENOSPC out
early even though we could commit the transaction and get that space back. So
now just unconditionally commit the transaction since currently there is no way
to know how much metadata space is being reserved by delayed inode stuff.
Thanks,
Josef Bacik [Thu, 13 Oct 2011 17:09:22 +0000 (13:09 -0400)]
Btrfs: fix regression in re-setting a large xattr
Recently I changed the xattr stuff to unconditionally set the xattr first in
case the xattr didn't exist yet. This has introduced a regression when setting
an xattr that already exists with a large value. If we find the key we are
looking for split_leaf will assume that we're extending that item. The problem
is the size we pass down to btrfs_search_slot includes the size of the item
already, so if we have the largest xattr we can possibly have plus the size of
the xattr item plus the xattr item that btrfs_search_slot we'd overflow the
leaf. Thankfully this is not what we're doing, but split_leaf doesn't know this
so it just returns EOVERFLOW. So in the xattr code we need to check and see if
we got back EOVERFLOW and treat it like EEXIST since that's really what
happened. Thanks,
Josef Bacik [Tue, 11 Oct 2011 18:18:24 +0000 (14:18 -0400)]
Btrfs: fix the amount of space reserved for unlink
Our unlink reservations were a bit much, we were reserving 10 and I only count 8
possible items we're touching, so comment what we're reserving for and fix the
count value. Thanks,
Josef Bacik [Fri, 7 Oct 2011 15:55:34 +0000 (11:55 -0400)]
Btrfs: wait for ordered extents if we didn't reclaim enough
I noticed recently that my overcommit patch was causing one of my enospc tests
to fail 25% of the time with early ENOSPC. This is because my overcommit patch
was letting us go way over board, but it wasn't waiting long enough to let the
delalloc shrinker do it's job. The problem is we just start writeback and wait
a little bit hoping we flush enough, but we only free up delalloc space by
having the writes complete all the way. We do this by waiting for ordered
extents, which we do but only if we already free'd enough for the reservation,
which isn't right, we should flush ordered extents if we didn't reclaim enough
in case that will push us over the edge. With this patch I've not seen a
failure in this enospc test after running it in a loop for an hour. Thanks,
Josef Bacik [Thu, 6 Oct 2011 12:58:24 +0000 (08:58 -0400)]
Btrfs: inline checksums into the disk free space cache
Yeah yeah I know this is how we used to do it and then I changed it, but damnit
I'm changing it back. The fact is that writing out checksums will modify
metadata, which could cause us to dirty a block group we've already written out,
so we have to truncate it and all of it's checksums and re-write it which will
write new checksums which could dirty a blockg roup that has already been
written and you see where I'm going with this? This can cause unmount or really
anything that depends on a transaction to commit to take it's sweet damned time
to happen. So go back to the way it was, only this time we're specifically
setting NODATACOW because we can't go through the COW pathway anyway and we're
doing our own built-in cow'ing by truncating the free space cache. The other
new thing is once we truncate the old cache and preallocate the new space, we
don't need to do that song and dance at all for the rest of the transaction, we
can just overwrite the existing space with the new cache if the block group
changes for whatever reason, and the NODATACOW will let us do this fine. So
keep track of which transaction we last cleared our cache in and if we cleared
it in this transaction just say we're all setup and carry on. This survives
xfstests and stress.sh.
The inode cache will continue to use the normal csum infrastructure since it
only gets written once and there will be no more modifications to the fs tree in
a transaction commit.
Josef Bacik [Wed, 5 Oct 2011 20:35:28 +0000 (16:35 -0400)]
Btrfs: take overflow into account in reserving space
My overcommit stuff can be a little racy when we're filling up the disk with
fs_mark and we overcommit into things that quickly get used up for data. So use
num_bytes to see if we have enough available space so we're less likely to
overcommit ourselves out of the ability to make reservations. Thanks,
Josef Bacik [Wed, 5 Oct 2011 20:33:53 +0000 (16:33 -0400)]
Btrfs: check the return value of filemap_write_and_wait in the space cache
We need to check the return value of filemap_write_and_wait in the space cache
writeout code. Also don't set the inode's generation until we're sure nothing
else is going to fail. Thanks,
Josef Bacik [Wed, 5 Oct 2011 19:18:58 +0000 (15:18 -0400)]
Btrfs: add a io_ctl struct and helpers for dealing with the space cache
In writing and reading the space cache we have one big loop that keeps track of
which page we are on and then a bunch of sizeable loops underneath this big loop
to try and read/write out properly. Especially in the write case this makes
things hugely complicated and hard to follow, and makes our error checking and
recovery equally as complex. So add a io_ctl struct with a bunch of helpers to
keep track of the pages we have, where we are, if we have enough space etc.
This unifies how we deal with the pages we're writing and keeps all the messy
tracking internal. This allows us to kill the big loops in both the read and
write case and makes reviewing and chaning the write and read paths much
simpler. I've run xfstests and stress.sh on this code and it survives. Thanks,
Josef Bacik [Wed, 5 Oct 2011 14:00:18 +0000 (10:00 -0400)]
Btrfs: don't skip writing out a empty block groups cache
I noticed a slight bug where we will not bother writing out the block group
cache's space cache if it's space tree is empty. Since it could have a cluster
or pinned extents that need to be written out this is just not a valid test.
Thanks,
Josef Bacik [Mon, 3 Oct 2011 18:07:49 +0000 (14:07 -0400)]
Btrfs: introduce mount option no_space_cache
Some users have requested this and I've found I needed a way to disable cache
loading without actually clearing the cache, so introduce the no_space_cache
option. Before we check the super blocks cache generation field and if it was
populated we always turned space caching on. Now we check this and set the
space cache option on, and then parse the mount options so that if we want it
off it get's turned off. Then we check the mount option all the places we do
the caching work instead of checking the super's cache generation. This makes
things more consistent and lets us turn space caching off. Thanks,
Josef Bacik [Tue, 27 Sep 2011 15:01:30 +0000 (11:01 -0400)]
Btrfs: only inherit btrfs specific flags when creating files
Xfstests 79 was failing because we were inheriting the S_APPEND flag when we
weren't supposed to. There isn't any specific documentation on this so I'm
taking the test as the standard of how things work, and having S_APPEND set on a
directory doesn't mean that S_APPEND gets inherited by its children according to
this test. So only inherit btrfs specific things. This will let us set
compress/nocompress on specific directories and everything in the directories
will inherit this flag, same with nodatacow. With this patch test 79 passes.
Thanks,
Josef Bacik [Mon, 26 Sep 2011 21:12:22 +0000 (17:12 -0400)]
Btrfs: allow us to overcommit our enospc reservations
One of the things that kills us is the fact that our ENOSPC reservations are
horribly over the top in most normal cases. There isn't too much that can be
done about this because when we are completely full we really need them to work
like this so we don't under reserve. However if there is plenty of unallocated
chunks on the disk we can use that to gauge how much we can overcommit. So this
patch adds chunk free space accounting so we always know how much unallocated
space we have. Then if we fail to make a reservation within our allocated
space, check to see if we can overcommit. In the normal flushing case (like
with delalloc metadata reservations) we'll take the free space and divide it by
2 if our metadata profile is setup for DUP or any of those, and then divide it
by 8 to make sure we don't overcommit too much. Then if we're in a non-flushing
case (we really need this reservation now!) we only limit ourselves to half of
the free space. This makes this fio test
go from taking around 45 minutes to 10 seconds on my freshly formatted 3 TiB
file system. This doesn't seem to break my other enospc tests, but could really
use some more testing as this is a super scary change. Thanks,
Josef Bacik [Mon, 26 Sep 2011 19:55:20 +0000 (15:55 -0400)]
Btrfs: break out of orphan cleanup if we can't make progress
I noticed while running xfstests 83 that if we didn't have enough space to
delete our inode the orphan cleanup would just loop. This is because it keeps
finding the same orphan item and keeps trying to kill it but can't because we
don't get an error back from iput for deleting the inode. So keep track of the
last guy we tried to kill, if it's the same as the one we're trying to kill
currently we know we are having problems and can just error out. I don't have a
way to test this so look hard and make sure it's right. Thanks,
Josef Bacik [Mon, 26 Sep 2011 19:46:06 +0000 (15:46 -0400)]
Btrfs: use the global reserve as a backup for deleting inodes
Xfstests 83 really stresses our ENOSPC since it uses a 100mb fs which ends up
with the mixed block group stuff. Because of this we can run into a situation
where we don't have enough space to delete inodes, or even worse we can't free
the inodes when we next mount the fs which causes the orphan code to lose its
mind. So if we fail to make our reservation, steal from the global reserve.
The global reserve will end up taking up the entire rest of the free space on
the fs in this worst case so there really is no other option. With this patch
test 83 doesn't freak out. Thanks,
Josef Bacik [Mon, 26 Sep 2011 17:58:47 +0000 (13:58 -0400)]
Btrfs: stop using write_one_page
While looking for a performance regression a user was complaining about, I
noticed that we had a regression with the varmail test of filebench. This was
introduced by
which keeps us from calling writepages in writepage. This is a correct change,
however it happens to help the varmail test because we write out in larger
chunks. This is largly to do with how we write out dirty pages for each
transaction. If you run filebench with
load varmail
set $dir=/mnt/btrfs-test
run 60
prior to this patch you would get ~1420 ops/second, but with the patch you get
~1200 ops/second. This is a 16% decrease. So since we know the range of dirty
pages we want to write out, don't write out in one page chunks, write out in
ranges. So to do this we call filemap_fdatawrite_range() on the range of bytes.
Then we convert the DIRTY extents to NEED_WAIT extents. When we then call
btrfs_wait_marked_extents() we only have to filemap_fdatawait_range() on that
range and clear the NEED_WAIT extents. This doesn't get us back to our original
speeds, but I've been seeing ~1380 ops/second, which is a <5% regression as
opposed to a >15% regression. That is acceptable given that the original commit
greatly reduces our latency to begin with. Thanks,
Josef Bacik [Mon, 26 Sep 2011 17:56:12 +0000 (13:56 -0400)]
Btrfs: introduce convert_extent_bit
If I have a range where I know a certain bit is and I want to set it to another
bit the only option I have is to call set and then clear bit, which will result
in 2 tree searches. This is inefficient, so introduce convert_extent_bit which
will go through and set the bit I want and clear the old bit I don't want.
Thanks,
Josef Bacik [Thu, 22 Sep 2011 18:30:02 +0000 (14:30 -0400)]
Btrfs: check unused against how much space we actually want
There is a bug that may lead to early ENOSPC in our reservation code. We've
been checking against num_bytes which may be above and beyond what we want to
actually reserve, which could give us a false ENOSPC. Fix this by making sure
the unused space is above how much we want to reserve and not how much we're
trying to flush. Thanks,
Josef Bacik [Wed, 21 Sep 2011 20:55:59 +0000 (16:55 -0400)]
Btrfs: fix orphan cleanup regression
In fixing how we deal with bad inodes, we had a regression in the orphan cleanup
code, since it expects to get a bad inode back. So fix it to deal with getting
-ESTALE back by deleting the orphan item manually and moving on. Thanks,
Josef Bacik [Wed, 21 Sep 2011 19:05:58 +0000 (15:05 -0400)]
Btrfs: use the inode's mapping mask for allocating pages
Johannes pointed out we were allocating only kernel pages for doing writes,
which is kind of a big deal if you are on 32bit and have more than a gig of ram.
So fix our allocations to use the mapping's gfp but still clear __GFP_FS so we
don't re-enter. Thanks,
Reported-by: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Josef Bacik <josef@redhat.com>
(cherry picked from commit 3b16a4e3c355ee3c790473decfcf83d4faeb8ce0)
Josef Bacik [Mon, 19 Sep 2011 16:26:24 +0000 (12:26 -0400)]
Btrfs: delay iput when deleting a block group
I kept getting warnings from evict because we were calling
btrfs_start_transaction() with a transaction already started when doing a
balance. This is because we remove a block group which requires a transaction,
and the put the last reference on the cache inode. Instead of doing this we
need to delay the iput so it is done not within a transaction having started.
This gets rid of our warnings. Thanks,
Josef Bacik [Mon, 19 Sep 2011 15:58:54 +0000 (11:58 -0400)]
Btrfs: make sure to unset trans->block_rsv before running delayed refs
Checksums are charged in 2 different ways. The first case is when we're writing
to the disk, we account for the new checksums with the delalloc block rsv. In
order for this to work we check if we're allocating a block for the csum root
and if trans->block_rsv == the delalloc block rsv. But when we're deleting the
csums because of cow, this is charged to the global block rsv, and is done when
we run the delayed refs. So we need to make sure that trans->block_rsv == NULL
when running the delayed refs. So set it to NULL and reset it in
should_end_transaction, and set it to NULL in commit_transaction. This got rid
of the ridiculous amount of warnings I was seeing when trying to do a balance.
Thanks,
Josef Bacik [Tue, 30 Aug 2011 16:34:28 +0000 (12:34 -0400)]
Btrfs: stop passing a trans handle all around the reservation code
The only thing that we need to have a trans handle for is in
reserve_metadata_bytes and thats to know how much flushing we can do. So
instead of passing it around, just check current->journal_info for a
trans_handle so we know if we can commit a transaction to try and free up space
or not. Thanks,
Josef Bacik [Tue, 30 Aug 2011 15:31:29 +0000 (11:31 -0400)]
Btrfs: use the transactions block_rsv for the csum root
The alloc warnings everybody has been seeing is because we have been reserving
space for csums, but we weren't actually using that space. So make
get_block_rsv() return the trans->block_rsv if we're modifying the csum root.
Also set the trans->block_rsv to NULL so that if we modify the csum root when
running delayed ref's that comes out of the global reserve like it's supposed
to. With this patch I'm not seeing those alloc warnings anymore. Thanks,
Josef Bacik [Tue, 30 Aug 2011 14:19:10 +0000 (10:19 -0400)]
Btrfs: handle enospc accounting for free space inodes
Since free space inodes now use normal checksumming we need to make sure to
account for their metadata use. So reserve metadata space, and then if we fail
to write out the metadata we can just release it, otherwise it will be freed up
when the io completes. Thanks,
Josef Bacik [Mon, 29 Aug 2011 18:06:00 +0000 (14:06 -0400)]
Btrfs: put the block group cache after we commit the super
In moving some enospc stuff around I noticed that when we unmount we are often
evicting the free space cache inodes before we do our last commit. This isn't
bad, but it makes us constantly have to re-read the inodes back. So instead
don't evict the cache until after we do our last commit, this will make things a
little less crappy and makes a future enospc change work properly. Thanks,
Josef Bacik [Mon, 29 Aug 2011 15:01:31 +0000 (11:01 -0400)]
Btrfs: set truncate block rsv's size
While debugging a different issue I noticed that we were always reserving space
when we tried to use our truncate block rsv's. This is because they didn't have
a ->size value, so use_block_rsv just assumes there is nothing reserved and it
does a reserve_metadata_bytes. This is because btrfs_check_block_rsv() doesn't
actually add to the size of the block rsv. That seems to be the right thing to
do so set ->size to the minimum truncate size we need, since we will always only
refill to that size anyway, and this way everything works out correctly.
Josef Bacik [Mon, 22 Aug 2011 19:23:19 +0000 (15:23 -0400)]
Btrfs: don't increase the block_rsv's size when emergency allocating space
If we have to emergency reserve space we need to not increase the block_rsv
size, otherwise we'll leak space. Take for instance delalloc, say we reserve
4k, and we use that 4k, and then we have to emergency allocate another 4k, we
bump the size up to 8k, however we've only accounted for 4k in reservations in
all of our supporting logic, so we'll go to free the 4k and end up having a size
of 4k, which will cause us to later not free as much space. I saw this doing
testing where I wasn't reserving enough space for something but was still
leaking space, very frustrating. Thanks,
Josef Bacik [Fri, 19 Aug 2011 19:45:52 +0000 (15:45 -0400)]
Btrfs: fix space leak when we fail to make an allocation
When changing back to using a spin_lock to protect the extent counters I decided
that since we would only be dropping our original extent, it was ok to just drop
the extent and return. However since somebody else could have come in and done
a reservation, we need to do the normal song and dance to clear the reservation
out properly. So calculate how much space we need to free, and then subtract
what we just attempted to reserve. If it's more then we know we need to drop
those bytes from the delalloc block rsv. Thanks,
Josef Bacik [Fri, 19 Aug 2011 16:06:12 +0000 (12:06 -0400)]
Btrfs: fix call to btrfs_search_slot in free space cache
We are setting ins_len to 1 even tho we are just modifying an item that should
be there already. This may cause the search stuff to split nodes on the way
down needelessly. Set this to 0 since we aren't inserting anything. Thanks,
Josef Bacik [Fri, 19 Aug 2011 14:31:56 +0000 (10:31 -0400)]
Btrfs: allow callers to specify if flushing can occur for btrfs_block_rsv_check
If you run xfstest 224 it you will get lots of messages about not being able to
delete inodes and that they will be cleaned up next mount. This is because
btrfs_block_rsv_check was not calling reserve_metadata_bytes with the ability to
flush, so if there was not enough space, it simply failed. But in truncate and
evict case we could easily flush space to try and get enough space to do our
work, so make btrfs_block_rsv_check take a flush argument to pass down to
reserve_metadata_bytes. Now xfstests 224 runs fine without all those
complaints. Thanks,
Josef Bacik [Fri, 19 Aug 2011 14:29:59 +0000 (10:29 -0400)]
Btrfs: reduce the amount of space needed for truncates
With btrfs_truncate_inode_items we always return if we have to go to another
leaf, which makes us do our reservation again. This means we will only ever
modify one leaf at a time, so we only need 1 items worth of slack space. Also,
since we are deleting we will not be creating nodes as we go down, if anything
we'll be free'ing them as we merge them together, so make a different
calculation for truncate which will only have the worst case useage of COW'ing
the entire path down to the leaf. Thanks,
Josef Bacik [Wed, 17 Aug 2011 14:19:52 +0000 (10:19 -0400)]
Btrfs: only reserve space in fallocate if we have to do a preallocate
Lukas found a problem where if he tries to fallocate over the same region twice
and the first fallocate took up all the space we would fail with ENOSPC. This
is because we reserve the total space we want to use for fallocate, regardless
of wether or not we will have to actually preallocate. So instead move the
check into the loop where we actually have to do the preallocate. Thanks,
Tested-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Josef Bacik <josef@redhat.com>
(cherry picked from commit 1b9c332b6c92e992b1971a08412c6f460a54b514)
Josef Bacik [Mon, 8 Aug 2011 17:46:15 +0000 (13:46 -0400)]
Btrfs: optimize how we account for space in truncate
Currently we're starting and stopping a transaction for no real reason, so kill
that and just reserve enough space as if we can truncate all in one transaction.
Also use btrfs_block_rsv_check() for our reserve to minimize the amount of space
we may have to allocate for our slack space. Thanks,
Josef Bacik [Mon, 8 Aug 2011 17:33:21 +0000 (13:33 -0400)]
Btrfs: don't try to commit in btrfs_block_rsv_check
We will try and reserve metadata bytes in btrfs_block_rsv_check and if we cannot
because we have a transaction open it will return EAGAIN, so we do not need to
try and commit the transaction again.
Josef Bacik [Mon, 8 Aug 2011 12:24:46 +0000 (08:24 -0400)]
Btrfs: ratelimit the generation printk for the free space cache
A user reported getting spammed when moving to 3.0 by this message. Since we
switched to the normal checksumming infrastructure all old free space caches
will be wrong and need to be regenerated so people are likely to see this
message a lot, so ratelimit it so it doesn't fill up their logs and freak them
out. Thanks,
Reported-by: Andrew Lutomirski <luto@mit.edu> Signed-off-by: Josef Bacik <josef@redhat.com>
(cherry picked from commit 6ab60601d518d563ca1a47eaa399096e69d3b64a)
Josef Bacik [Fri, 5 Aug 2011 17:22:24 +0000 (13:22 -0400)]
Btrfs: fix how we reserve space for deleting inodes
I converted btrfs_truncate to do sane reservations for truncate, but didn't
convert btrfs_evict_inode. Basically we need to save the orphan_rsv for
deleting the orphan item, and do normal reservations for our truncate. Thanks,
Josef Bacik [Thu, 4 Aug 2011 19:34:57 +0000 (15:34 -0400)]
Btrfs: kill the orphan space calculation for snapshots
This patch kills off the calculation for the amount of space needed for the
orphan operations during a snapshot. The thing is we only do snapshots on
commit, so any space that is in the block_rsv->freed[] isn't going to be in the
new snapshot anyway, so there isn't any reason to require that space to be
reserved for the snapshot to occur. Thanks,
Josef Bacik [Thu, 4 Aug 2011 14:25:02 +0000 (10:25 -0400)]
Btrfs: calculate checksum space correctly
We have not been reserving enough space for checksums. We were just reserving
bytes for the checksum items themselves, we were not taking into account having
to cow the tree and such. This patch adds a csum_bytes counter to the inode for
keeping track of the number of bytes outstanding we have for checksums. Then we
calculate how many leaves would be required for the checksums we are given and
use that to reserve space. This adds a significant amount of bytes to our
reservations, but we will handle this later. Thanks,
Josef Bacik [Mon, 1 Aug 2011 16:08:18 +0000 (12:08 -0400)]
Btrfs: skip looking for delalloc if we don't have ->fill_delalloc
We always look for delalloc bytes in our io_tree so we can fill in delalloc.
This is fine in most cases, but if we're writing out the btree_inode this is
just a superfluous tree search on the io_tree, and if we have a lot of metadata
dirty this could be an expensive check. So instead check to see if our io_tree
has a ->fill_delalloc op, and if not don't even bother doing the lookup.
Thanks,
Josef Bacik [Tue, 26 Jul 2011 21:00:46 +0000 (17:00 -0400)]
Btrfs: use bytes_may_use for all ENOSPC reservations
We have been using bytes_reserved for metadata reservations, which is wrong
since we use that to keep track of outstanding reservations from the allocator.
This resulted in us doing a lot of silly things to make sure we don't allocate a
bunch of metadata chunks since we never had a real view of how much space was
actually in use by metadata.
This passes Arne's enospc test and xfstests as well as my own enospc tests.
Hopefully this will get us moving in the right direction. Thanks,
Josef Bacik [Mon, 25 Jul 2011 19:55:42 +0000 (15:55 -0400)]
Btrfs: fix how we mount subvol=<whatever>
We've only been able to mount with subvol=<whatever> where whatever was a subvol
within whatever root we had as the default. This allows us to mount -o
subvol=path/to/subvol/you/want relative from the normal fs_tree root. Thanks,
Josef Bacik [Mon, 25 Jul 2011 19:40:35 +0000 (15:40 -0400)]
Btrfs: use d_obtain_alias when mounting subvol/subvolid
Currently what we do is just wrong. We either
1) Alloc a new "root" dentry with sb->s_root as it's parent which is just wrong
as we could walk into this subvol later on via another path and hilarity could
ensue. Also we don't check the return value of d_splice_alias which isn't good
either.
or
2) Do a d_find_alias() which we could have lost our dentry from cache at this
point and found nothing.
So use d_obtain_alias(). In the case that we already have the inode/dentry in
cache we will get the correct dentry. If not we will get a disconnected dentry
tree so if we walk into it later on everything will be connected up properly.
Thanks,
Chris Mason [Tue, 11 Oct 2011 15:41:40 +0000 (11:41 -0400)]
Btrfs: make sure not to defrag extents past i_size
The btrfs file defrag code will loop through the extents and
force COW on them. But there is a concurrent truncate in the middle of
the defrag, it might end up defragging the same range over and over
again.
The problem is that writepage won't go through and do anything on pages
past i_size, so the cow won't happen, so the file will appear to still
be fragmented. defrag will end up hitting the same extents again and
again.
In the worst case, the truncate can actually live lock with the defrag
because the defrag keeps creating new ordered extents which the truncate
code keeps waiting on.
The fix here is to make defrag check for i_size inside the main loop,
instead of just once before the looping starts.
and then it'll go into a loop: writeback -> defrag -> writeback ...
It's because writeback writes [8K, 200K] and then writes [0, 8K].
I tried to make writeback know if the pages are dirtied by defrag,
but the patch was a bit intrusive. Here I simply set writeback_index
when we defrag a file.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
(cherry picked from commit 2a0f7f5769992bae5b3f97157fd80b2b943be485)
Arne Jansen [Fri, 10 Jun 2011 10:39:23 +0000 (12:39 +0200)]
btrfs: use readahead API for scrub
Scrub uses a simple tree-enumeration to bring the relevant portions
of the extent- and csum-tree into the page cache before starting the
scrub-I/O. This is now replaced by using the new readahead-API.
During readahead the scrub is being accounted as paused, so it won't
hold off transaction commits.
This change raises the average disk bandwith utilisation on my test
volume from 70% to 90%. On another volume, the time for a test run
went down from 89s to 43s.
Changes v5:
- reada1/2 are now of type struct reada_control *
Arne Jansen [Fri, 10 Jun 2011 11:55:54 +0000 (13:55 +0200)]
btrfs: hooks for readahead
This adds the hooks needed for readahead. In the readpage_end_io_hook,
the extent state is checked for the EXTENT_READAHEAD flag. Only in this
case the readahead hook is called, to keep the impact on non-ra as low
as possible.
Additionally, a hook for a failed IO is added, otherwise readahead would
wait indefinitely for the extent to finish.
Arne Jansen [Mon, 23 May 2011 12:33:49 +0000 (14:33 +0200)]
btrfs: initial readahead code and prototypes
This is the implementation for the generic read ahead framework.
To trigger a readahead, btrfs_reada_add must be called. It will start
a read ahead for the given range [start, end) on tree root. The returned
handle can either be used to wait on the readahead to finish
(btrfs_reada_wait), or to send it to the background (btrfs_reada_detach).
The read ahead works as follows:
On btrfs_reada_add, the root of the tree is inserted into a radix_tree.
reada_start_machine will then search for extents to prefetch and trigger
some reads. When a read finishes for a node, all contained node/leaf
pointers that lie in the given range will also be enqueued. The reads will
be triggered in sequential order, thus giving a big win over a naive
enumeration. It will also make use of multi-device layouts. Each disk
will have its on read pointer and all disks will by utilized in parallel.
Also will no two disks read both sides of a mirror simultaneously, as this
would waste seeking capacity. Instead both disks will read different parts
of the filesystem.
Any number of readaheads can be started in parallel. The read order will be
determined globally, i.e. 2 parallel readaheads will normally finish faster
than the 2 started one after another.
Changes v2:
- protect root->node by transaction instead of node_lock
- fix missed branches:
The readahead had a too simple check to determine if a branch from
a node should be checked or not. It now also records the upper bound
of each node to see if the requested RA range lies within.
- use KERN_CONT to debug output, to avoid line breaks
- defer reada_start_machine to worker to avoid deadlock
Changes v3:
- protect root->node by rcu
Changes v5:
- changed EIO-semantics of reada_tree_block_flagged
- remove spin_lock from reada_control and make elems an atomic_t
- remove unused read_total from reada_control
- kill reada_key_cmp, use btrfs_comp_cpu_keys instead
- use kref-style release functions where possible
- return struct reada_control * instead of void * from btrfs_reada_add
Arne Jansen [Fri, 10 Jun 2011 12:06:53 +0000 (14:06 +0200)]
btrfs: add an extra wait mode to read_extent_buffer_pages
read_extent_buffer_pages currently has two modes, either trigger a read
without waiting for anything, or wait for the I/O to finish. The former
also bails when it's unable to lock the page. This patch now adds an
additional parameter to allow it to block on page lock, but don't wait
for completion.
Changes v5:
- merge the 2 wait parameters into one and define WAIT_NONE, WAIT_COMPLETE and
WAIT_PAGE_LOCK
Josef Bacik [Fri, 30 Sep 2011 19:23:54 +0000 (15:23 -0400)]
Btrfs: force a page fault if we have a shorty copy on a page boundary
A user reported a problem where ceph was getting into 100% cpu usage while doing
some writing. It turns out it's because we were doing a short write on a not
uptodate page, which means we'd fall back at one page at a time and fault the
page in. The problem is our position is on the page boundary, so our fault in
logic wasn't actually reading the page, so we'd just spin forever or until the
page got read in by somebody else. This will force a readpage if we end up
doing a short copy. Alexandre could reproduce this easily with ceph and reports
it fixes his problem. I also wrote a reproducer that no longer hangs my box
with this patch. Thanks,
Reported-and-tested-by: Alexandre Oliva <aoliva@redhat.com> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
(cherry picked from commit b6316429af7f365f307dfd2b6a7a42f2563aef19)
Chris Mason [Wed, 2 Nov 2011 19:48:34 +0000 (15:48 -0400)]
Btrfs: fix the new inspection ioctls for 32 bit compat
The new ioctls to follow backrefs are not clean for 32/64 bit
compat. This reworks them for u64s everywhere. They are brand new, so
there are no problems with changing the interface now.
Jan Schmidt [Thu, 4 Aug 2011 16:11:04 +0000 (18:11 +0200)]
btrfs: integrating raid-repair and scrub-fixup-nodatasum
This ties nodatasum fixup in scrub together with raid repair patches. While
both series are working fine alone, scrub will report uncorrectable errors
if they occur in a nodatasum extent *and* the page is in the page cache.
Previously, we would have triggered readpage to find good data and do the
repair. However, readpage wouldn't read anything in the case where the page
is up to date in the cache. So, we simply take that good data we have and
call repair_io_failure directly (unless the page in the cache is dirty).
Jan Schmidt [Fri, 22 Jul 2011 13:41:52 +0000 (15:41 +0200)]
btrfs: Moved repair code from inode.c to extent_io.c
The raid-retry code in inode.c can be generalized so that it works for
metadata as well. Thus, this patch moves it to extent_io.c and makes the
raid-retry code a raid-repair code.
Repair works that way: Whenever a read error occurs and we have more
mirrors to try, note the failed mirror, and retry another. If we find a
good one, check if we did note a failure earlier and if so, do not allow
the read to complete until after the bad sector was written with the good
data we just fetched. As we have the extent locked while reading, no one
can change the data in between.
Jan Schmidt [Thu, 16 Jun 2011 10:05:19 +0000 (12:05 +0200)]
btrfs: Put mirror_num in bi_bdev
The error correction code wants to make sure that only the bad mirror is
rewritten. Thus, we need to know which mirror is the bad one. I did not
find a more apropriate field than bi_bdev. But I think using this is fine,
because it is modified by the block layer, anyway, and should not be read
after the bio returned.
Jan Schmidt [Thu, 16 Jun 2011 12:37:03 +0000 (14:37 +0200)]
btrfs: Do not use bio->bi_bdev after submission
The block layer modifies bio->bi_bdev and bio->bi_sector while working on
the bio, they do _not_ come back unmodified in the completion callback.
To call add_page, we need at least some bi_bdev set, which is why the code
was working, previously. With this patch, we use the latest_bdev from
fsinfo instead of the leftover in the bio. This gives us the possibility to
use the bi_bdev field for another purpose.
Jan Schmidt [Thu, 4 Aug 2011 15:15:33 +0000 (17:15 +0200)]
btrfs: btrfs_multi_bio replaced with btrfs_bio
btrfs_bio is a bio abstraction able to split and not complete after the last
bio has returned (like the old btrfs_multi_bio). Additionally, btrfs_bio
tracks the mirror_num used to read data which can be used for error
correction purposes.
Jan Schmidt [Thu, 7 Jul 2011 14:48:38 +0000 (16:48 +0200)]
btrfs: new ioctls to do logical->inode and inode->path resolving
these ioctls make use of the new functions initially added for scrub. they
return all inodes belonging to a logical address (BTRFS_IOC_LOGICAL_INO) and
all paths belonging to an inode (BTRFS_IOC_INO_PATHS).
Jan Schmidt [Mon, 13 Jun 2011 18:04:15 +0000 (20:04 +0200)]
btrfs scrub: add fixup code for errors on nodatasum files
This removes a FIXME comment and introduces the first part of nodatasum
fixup: It gets the corresponding inode for a logical address and triggers a
regular readpage for the corrupted sector.
Once we have on-the-fly error correction our error will be automatically
corrected. The correction code is expected to clear the newly introduced
EXTENT_DAMAGED flag, making scrub report that error as "corrected" instead
of "uncorrectable" eventually.
Jan Schmidt [Mon, 13 Jun 2011 18:02:58 +0000 (20:02 +0200)]
btrfs: add mirror_num to extent_read_full_page
Currently, extent_read_full_page always assumes we are trying to read mirror
0, which generally is the best we can do. To add flexibility, pass it as a
parameter. This will be needed by scrub fixup code.
Jan Schmidt [Mon, 13 Jun 2011 17:56:54 +0000 (19:56 +0200)]
btrfs scrub: bugfix: mirror_num off by one
Fix the mirror_num determination in scrub_stripe. The rest of the scrub code
did not use mirror_num for anything important and that error went unnoticed.
The nodatasum fixup patch of this set depends on a correct mirror_num.
Jan Schmidt [Mon, 13 Jun 2011 17:59:12 +0000 (19:59 +0200)]
btrfs scrub: print paths of corrupted files
While scrubbing, we may encounter various errors. Previously, a logical
address was printed to the log only. Now, all paths belonging to that
address are resolved and printed separately. That should work for hardlinks
as well as reflinks.
Jan Schmidt [Mon, 13 Jun 2011 17:56:13 +0000 (19:56 +0200)]
btrfs scrub: added unverified_errors
In normal operation, scrub is reading data sequentially in large portions.
In case of an i/o error, we try to find the corrupted area(s) by issuing
page sized read requests. With this commit we increment the
unverified_errors counter if all of the small size requests succeed.
Userland patches carrying such conspicous events to the administrator should
already be around.
Jan Schmidt [Mon, 13 Jun 2011 17:52:59 +0000 (19:52 +0200)]
btrfs: added helper functions to iterate backrefs
These helper functions iterate back references and call a function for each
backref. There is also a function to resolve an inode to a path in the
file system.
Jeff Mahoney [Mon, 15 Aug 2011 17:27:21 +0000 (17:27 +0000)]
btrfs: btrfs_permission's RO check shouldn't apply to device nodes
This patch tightens the read-only access checks in btrfs_permission to
match the constraints in inode_permission. Currently, even though the
device node itself will be unmodified, read-write access to device nodes
is denied to when the device node resides on a read-only subvolume or a
is a file that has been marked read-only by the btrfs conversion utility.
With this patch applied, the check only affects regular files,
directories, and symlinks. It also restructures the code a bit so that
we don't duplicate the MAY_WRITE check for both tests.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
(cherry picked from commit cb6db4e57632ba8589cc2f9fe1d0aa9116b87ab8 with conflicts)
projects / users / jedix / linux-maple.git / log