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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
Since the durable block rsv stuff has been killed there is no need to get the
block_rsv in btrfs_free_tree_block anymore.
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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.
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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.
Signed-off-by: Josef Bacik <josef@redhat.com>
The priority and refill_used flags are not used anymore, and neither is the
usage counter, so just remove them from btrfs_block_rsv.
Signed-off-by: Josef Bacik <josef@redhat.com>
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>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
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,
Signed-off-by: Josef Bacik <josef@redhat.com>
Moving things around to give us better packing in the btrfs_inode. This reduces
the size of our inode by 8 bytes. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
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.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Follow those steps:
# mount -o autodefrag /dev/sda7 /mnt
# dd if=/dev/urandom of=/mnt/tmp bs=200K count=1
# sync
# dd if=/dev/urandom of=/mnt/tmp bs=8K count=1 conv=notrunc
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>
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 *
Signed-off-by: Arne Jansen <sensille@gmx.net>
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.
Changes for v2:
- eliminate race condition
Signed-off-by: Arne Jansen <sensille@gmx.net>
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
Signed-off-by: Arne Jansen <sensille@gmx.net>
Add state information for readahead to btrfs_fs_info and btrfs_device
Changes v2:
- don't wait in radix_trees
- add own set of workers for readahead
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Arne Jansen <sensille@gmx.net>
Add a READAHEAD extent buffer flag.
Add a function to trigger a read with this flag set.
Changes v2:
- use extent buffer flags instead of extent state flags
Changes v5:
- adapt to changed read_extent_buffer_pages interface
- don't return eb from reada_tree_block_flagged if it has CORRUPT flag set
Signed-off-by: Arne Jansen <sensille@gmx.net>
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
Change v6:
- fix bug introduced in v5
Signed-off-by: Arne Jansen <sensille@gmx.net>
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>
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).
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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).
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
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.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
