Pull btrfs fixes from Chris Mason:
"Miao Xie has been very busy, fixing races and enospc problems and many
other small but important pieces.
Alexandre Oliva discovered some problems with how our error handling
was interacting with the block layer and for now has disabled our
partial handling of sub-page writes. The real sub-page work is in a
series of patches from IBM that we still need to integrate and test.
The code Alexandre has turned off was really incomplete.
Josef has more error handling fixes and an important fix for the new
skinny extent format.
This also has my fix for the tracepoint crash from late in 3.9. It's
the first stage in a larger clean up to get rid of btrfs_bio and make
a proper bioset for all the items we need to tack into the bio. For
now the bioset only holds our mirror_num and stripe_index, but for the
next merge window I'll shuffle more in."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (25 commits)
Btrfs: use a btrfs bioset instead of abusing bio internals
Btrfs: make sure roots are assigned before freeing their nodes
Btrfs: explicitly use global_block_rsv for quota_tree
btrfs: do away with non-whole_page extent I/O
Btrfs: don't invoke btrfs_invalidate_inodes() in the spin lock context
Btrfs: remove BUG_ON() in btrfs_read_fs_tree_no_radix()
Btrfs: pause the space balance when remounting to R/O
Btrfs: fix unprotected root node of the subvolume's inode rb-tree
Btrfs: fix accessing a freed tree root
Btrfs: return errno if possible when we fail to allocate memory
Btrfs: update the global reserve if it is empty
Btrfs: don't steal the reserved space from the global reserve if their space type is different
Btrfs: optimize the error handle of use_block_rsv()
Btrfs: don't use global block reservation for inode cache truncation
Btrfs: don't abort the current transaction if there is no enough space for inode cache
Correct allowed raid levels on balance.
Btrfs: fix possible memory leak in replace_path()
Btrfs: fix possible memory leak in the find_parent_nodes()
Btrfs: don't allow device replace on RAID5/RAID6
Btrfs: handle running extent ops with skinny metadata
...
Btrfs has been pointer tagging bi_private and using bi_bdev
to store the stripe index and mirror number of failed IOs.
As bios bubble back up through the call chain, we use these
to decide if and how to retry our IOs. They are also used
to count IO failures on a per device basis.
Recently a bio tracepoint was added lead to crashes because
we were abusing bi_bdev.
This commit adds a btrfs bioset, and creates explicit fields
for the mirror number and stripe index. The plan is to
extend this structure for all of the fields currently in
struct btrfs_bio, which will mean one less kmalloc in
our IO path.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Tejun Heo <tj@kernel.org>
The root node of the rb-tree may be changed, so we should get it under
the lock. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
inode_tree_del() will move the tree root into the dead root list, and
then the tree will be destroyed by the cleaner. So if we remove the
delayed node which is cached in the inode after inode_tree_del(),
we may access a freed tree root. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We need to set return value explicitly, otherwise we'll lose the error
value.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull btrfs update from Chris Mason:
"These are mostly fixes. The biggest exceptions are Josef's skinny
extents and Jan Schmidt's code to rebuild our quota indexes if they
get out of sync (or you enable quotas on an existing filesystem).
The skinny extents are off by default because they are a new variation
on the extent allocation tree format. btrfstune -x enables them, and
the new format makes the extent allocation tree about 30% smaller.
I rebased this a few days ago to rework Dave Sterba's crc checks on
the super block, but almost all of these go back to rc6, since I
though 3.9 was due any minute.
The biggest missing fix is the tracepoint bug that was hit late in
3.9. I ran into problems with that in overnight testing and I'm still
tracking it down. I'll definitely have that fixed for rc2."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (101 commits)
Btrfs: allow superblock mismatch from older mkfs
btrfs: enhance superblock checks
btrfs: fix misleading variable name for flags
btrfs: use unsigned long type for extent state bits
Btrfs: improve the loop of scrub_stripe
btrfs: read entire device info under lock
btrfs: remove unused gfp mask parameter from release_extent_buffer callchain
btrfs: handle errors returned from get_tree_block_key
btrfs: make static code static & remove dead code
Btrfs: deal with errors in write_dev_supers
Btrfs: remove almost all of the BUG()'s from tree-log.c
Btrfs: deal with free space cache errors while replaying log
Btrfs: automatic rescan after "quota enable" command
Btrfs: rescan for qgroups
Btrfs: split btrfs_qgroup_account_ref into four functions
Btrfs: allocate new chunks if the space is not enough for global rsv
Btrfs: separate sequence numbers for delayed ref tracking and tree mod log
btrfs: move leak debug code to functions
Btrfs: return free space in cow error path
Btrfs: set UUID in root_item for created trees
...
Big patch, but all it does is add statics to functions which
are in fact static, then remove the associated dead-code fallout.
removed functions:
btrfs_iref_to_path()
__btrfs_lookup_delayed_deletion_item()
__btrfs_search_delayed_insertion_item()
__btrfs_search_delayed_deletion_item()
find_eb_for_page()
btrfs_find_block_group()
range_straddles_pages()
extent_range_uptodate()
btrfs_file_extent_length()
btrfs_scrub_cancel_devid()
btrfs_start_transaction_lflush()
btrfs_print_tree() is left because it is used for debugging.
btrfs_start_transaction_lflush() and btrfs_reada_detach() are
left for symmetry.
ulist.c functions are left, another patch will take care of those.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Replace some BUG_ONs with proper handling and take allocated space back to
free space cache for later use.
We don't have to worry about extent maps since they'd be freed in releasepage
path.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This is the same as the fix from commit
Btrfs: fix bad extent logging
but for O_DIRECT. I missed this when I fixed the problem originally, we were
still using the em for the orig_start and orig_block_len, which would be the
merged extent. We need to use the actual extent from the on disk file extent
item, which we have to lookup to make sure it's ok to nocow anyway so just pass
in some pointers to hold this info. Thanks,
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
If argument 'trans' is unnecessary in the function where
fixup_low_keys() is called, 'trans' is deleted.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
__btrfs_unlink_inode() aborts its transaction when it sees errors after
it removes the directory item. But it missed the case where
btrfs_del_dir_entries_in_log() returns an error. If this happens then
the unlink appears to fail but the items have been removed without
updating the directory size. The directory then has leaked bytes in
i_size and can never be removed.
Adding the missing transaction abort at least makes this failure
consistent with the other failure cases.
I noticed this while reading the code after someone on irc reported
having a directory with i_size but no entries. I tested it by forcing
btrfs_del_dir_entries_in_log() to return -ENOMEM.
Signed-off-by: Zach Brown <zab@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
A user sent me a btrfs-image of a file system that was panicing on mount during
the log recovery. I had originally thought these problems were from a bug in
the free space cache code, but that was just a symptom of the problem. The
problem is if your application does something like this
[prealloc][prealloc][prealloc]
the internal extent maps will merge those all together into one extent map, even
though on disk they are 3 separate extents. So if you go to write into one of
these ranges the extent map will be right since we use the physical extent when
doing the write, but when we log the extents they will use the wrong sizes for
the remainder prealloc space. If this doesn't happen to trip up the free space
cache (which it won't in a lot of cases) then you will get bogus entries in your
extent tree which will screw stuff up later. The data and such will still work,
but everything else is broken. This patch fixes this by not allowing extents
that are on the modified list to be merged. This has the side effect that we
are no longer adding everything to the modified list all the time, which means
we now have to call btrfs_drop_extents every time we log an extent into the
tree. So this allows me to drop all this speciality code I was using to get
around calling btrfs_drop_extents. With this patch the testcase I've created no
longer creates a bogus file system after replaying the log. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When logging changed extents I was logging ram_bytes as the current length,
which isn't correct, it's supposed to be the ram bytes of the original extent.
This is for compression where even if we split the extent we need to know the
ram bytes so when we uncompress the extent we know how big it will be. This was
still working out right with compression for some reason but I think we were
getting lucky. It was definitely off for prealloc which is why I noticed it,
btrfsck was complaining about it. With this patch btrfsck no longer complains
after a log replay. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The messages
btrfs: unlinked 123 orphans
btrfs: truncated 456 orphans
are not useful to regular users and raise questions whether there are
problems with the filesystem.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
With more than one btrfs volume mounted, it can be very difficult to find
out which volume is hitting an error. btrfs_error() will print this, but
it is currently rigged as more of a fatal error handler, while many of
the printk()s are currently for debugging and yet-unhandled cases.
This patch just changes the functions where the device information is
already available. Some cases remain where the root or fs_info is not
passed to the function emitting the error.
This may introduce some confusion with volumes backed by multiple devices
emitting errors referring to the primary device in the set instead of the
one on which the error occurred.
Use btrfs_printk(fs_info, format, ...) rather than writing the device
string every time, and introduce macro wrappers ala XFS for brevity.
Since the function already cannot be used for continuations, print a
newline as part of the btrfs_printk() message rather than at each caller.
Signed-off-by: Simon Kirby <sim@hostway.ca>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We currently store the first key of the tree block inside the reference for the
tree block in the extent tree. This takes up quite a bit of space. Make a new
key type for metadata which holds the level as the offset and completely removes
storing the btrfs_tree_block_info inside the extent ref. This reduces the size
from 51 bytes to 33 bytes per extent reference for each tree block. In practice
this results in a 30-35% decrease in the size of our extent tree, which means we
COW less and can keep more of the extent tree in memory which makes our heavy
metadata operations go much faster. This is not an automatic format change, you
must enable it at mkfs time or with btrfstune. This patch deals with having
metadata stored as either the old format or the new format so it is easy to
convert. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull btrfs fixes from Chris Mason:
"We've had a busy two weeks of bug fixing. The biggest patches in here
are some long standing early-enospc problems (Josef) and a very old
race where compression and mmap combine forces to lose writes (me).
I'm fairly sure the mmap bug goes all the way back to the introduction
of the compression code, which is proof that fsx doesn't trigger every
possible mmap corner after all.
I'm sure you'll notice one of these is from this morning, it's a small
and isolated use-after-free fix in our scrub error reporting. I
double checked it here."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: don't drop path when printing out tree errors in scrub
Btrfs: fix wrong return value of btrfs_lookup_csum()
Btrfs: fix wrong reservation of csums
Btrfs: fix double free in the btrfs_qgroup_account_ref()
Btrfs: limit the global reserve to 512mb
Btrfs: hold the ordered operations mutex when waiting on ordered extents
Btrfs: fix space accounting for unlink and rename
Btrfs: fix space leak when we fail to reserve metadata space
Btrfs: fix EIO from btrfs send in is_extent_unchanged for punched holes
Btrfs: fix race between mmap writes and compression
Btrfs: fix memory leak in btrfs_create_tree()
Btrfs: fix locking on ROOT_REPLACE operations in tree mod log
Btrfs: fix missing qgroup reservation before fallocating
Btrfs: handle a bogus chunk tree nicely
Btrfs: update to use fs_state bit
We reserve the space for csums only when we write data into a file, in
the other cases, such as tree log, log replay, we don't do reservation,
so we can use the reservation of the transaction handle just for the former.
And for the latter, we should use the tree's own reservation. But the
function - btrfs_csum_file_blocks() didn't differentiate between these
two types of the cases, fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We are way over-reserving for unlink and rename. Rename is just some random
huge number and unlink accounts for tree log operations that don't actually
happen during unlink, not to mention the tree log doesn't take from the trans
block rsv anyway so it's completely useless. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Btrfs uses page_mkwrite to ensure stable pages during
crc calculations and mmap workloads. We call clear_page_dirty_for_io
before we do any crcs, and this forces any application with the file
mapped to wait for the crc to finish before it is allowed to change
the file.
With compression on, the clear_page_dirty_for_io step is happening after
we've compressed the pages. This means the applications might be
changing the pages while we are compressing them, and some of those
modifications might not hit the disk.
This commit adds the clear_page_dirty_for_io before compression starts
and makes sure to redirty the page if we have to fallback to
uncompressed IO as well.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Alexandre Oliva <oliva@gnu.org>
cc: stable@vger.kernel.org
Pull btrfs fixes from Chris Mason:
"Eric's rcu barrier patch fixes a long standing problem with our
unmount code hanging on to devices in workqueue helpers. Liu Bo
nailed down a difficult assertion for in-memory extent mappings."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix warning of free_extent_map
Btrfs: fix warning when creating snapshots
Btrfs: return as soon as possible when edquot happens
Btrfs: return EIO if we have extent tree corruption
btrfs: use rcu_barrier() to wait for bdev puts at unmount
Btrfs: remove btrfs_try_spin_lock
Btrfs: get better concurrency for snapshot-aware defrag work
Using spinning case instead of blocking will result in better concurrency
overall.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Pull btrfs fixes from Chris Mason:
"These are scattered fixes and one performance improvement. The
biggest functional change is in how we throttle metadata changes. The
new code bumps our average file creation rate up by ~13% in fs_mark,
and lowers CPU usage.
Stefan bisected out a regression in our allocation code that made
balance loop on extents larger than 256MB."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: improve the delayed inode throttling
Btrfs: fix a mismerge in btrfs_balance()
Btrfs: enforce min_bytes parameter during extent allocation
Btrfs: allow running defrag in parallel to administrative tasks
Btrfs: avoid deadlock on transaction waiting list
Btrfs: do not BUG_ON on aborted situation
Btrfs: do not BUG_ON in prepare_to_reloc
Btrfs: free all recorded tree blocks on error
Btrfs: build up error handling for merge_reloc_roots
Btrfs: check for NULL pointer in updating reloc roots
Btrfs: fix unclosed transaction handler when the async transaction commitment fails
Btrfs: fix wrong handle at error path of create_snapshot() when the commit fails
Btrfs: use set_nlink if our i_nlink is 0
Commit 24542bf7ea changed preallocation of
extents to cap the max size we try to allocate. It's a valid change,
but the extent reservation code is also used by balance, and that
can't tolerate a smaller extent being allocated.
__btrfs_prealloc_file_range already has a min_size parameter, which is
used by relocation to request a specific extent size. This commit
adds an extra check to enforce that minimum extent size.
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Reported-by: Stefan Behrens <sbehrens@giantdisaster.de>
Pull btrfs update from Chris Mason:
"The biggest feature in the pull is the new (and still experimental)
raid56 code that David Woodhouse started long ago. I'm still working
on the parity logging setup that will avoid inconsistent parity after
a crash, so this is only for testing right now. But, I'd really like
to get it out to a broader audience to hammer out any performance
issues or other problems.
scrub does not yet correct errors on raid5/6 either.
Josef has another pass at fsync performance. The big change here is
to combine waiting for metadata with waiting for data, which is a big
latency win. It is also step one toward using atomics from the
hardware during a commit.
Mark Fasheh has a new way to use btrfs send/receive to send only the
metadata changes. SUSE is using this to make snapper more efficient
at finding changes between snapshosts.
Snapshot-aware defrag is also included.
Otherwise we have a large number of fixes and cleanups. Eric Sandeen
wins the award for removing the most lines, and I'm hoping we steal
this idea from XFS over and over again."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (118 commits)
btrfs: fixup/remove module.h usage as required
Btrfs: delete inline extents when we find them during logging
btrfs: try harder to allocate raid56 stripe cache
Btrfs: cleanup to make the function btrfs_delalloc_reserve_metadata more logic
Btrfs: don't call btrfs_qgroup_free if just btrfs_qgroup_reserve fails
Btrfs: remove reduplicate check about root in the function btrfs_clean_quota_tree
Btrfs: return ENOMEM rather than use BUG_ON when btrfs_alloc_path fails
Btrfs: fix missing deleted items in btrfs_clean_quota_tree
btrfs: use only inline_pages from extent buffer
Btrfs: fix wrong reserved space when deleting a snapshot/subvolume
Btrfs: fix wrong reserved space in qgroup during snap/subv creation
Btrfs: remove unnecessary dget_parent/dput when creating the pending snapshot
btrfs: remove a printk from scan_one_device
Btrfs: fix NULL pointer after aborting a transaction
Btrfs: fix memory leak of log roots
Btrfs: copy everything if we've created an inline extent
btrfs: cleanup for open-coded alignment
Btrfs: do not change inode flags in rename
Btrfs: use reserved space for creating a snapshot
clear chunk_alloc flag on retryable failure
...
I noticed while looking into a tree logging bug that we aren't logging inline
extents properly. Since this requires copying and it shouldn't happen too often
just force us to copy everything for the inode into the tree log when we have an
inline extent. With this patch we have valid data after a crash when we write
an inline extent. Thanks,
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
Though most of the btrfs codes are using ALIGN macro for page alignment,
there are still some codes using open-coded alignment like the
following:
------
u64 mask = ((u64)root->stripesize - 1);
u64 ret = (val + mask) & ~mask;
------
Or even hidden one:
------
num_bytes = (end - start + blocksize) & ~(blocksize - 1);
------
Sometimes these open-coded alignment is not so easy to understand for
newbie like me.
This commit changes the open-coded alignment to the ALIGN macro for a
better readability.
Also there is a previous patch from David Sterba with similar changes,
but the patch is for 3.2 kernel and seems not merged.
http://www.spinics.net/lists/linux-btrfs/msg12747.html
Cc: David Sterba <dave@jikos.cz>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Before we forced to change a file's NOCOW and COMPRESS flag due to
the parent directory's, but this ends up a bad idea, because it
confuses end users a lot about file's NOCOW status, eg. if someone
change a file to NOCOW via 'chattr' and then rename it in the current
directory which is without NOCOW attribute, the file will lose the
NOCOW flag silently.
This diables 'change flags in rename', so from now on we'll only
inherit flags from the parent directory on creation stage while in
other places we can use 'chattr' to set NOCOW or COMPRESS flags.
Reported-by: Marios Titas <redneb8888@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
A user reported hitting the BUG_ON() in btrfs_finished_ordered_io() where we had
csums on a NOCOW extent. This can happen if we have NODATACOW set but not
NODATASUM set, which can happen in two cases, either we mount with -o nodatacow
and then write into preallocated space, or chattr +C a directory and move a file
into that directory. Liu has fixed the move case in a different place, but this
fixes the mount -o nodatacow case. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When running the 083th case of xfstests on the filesystem with
"compress-force=lzo", the following WARNINGs were triggered.
WARNING: at fs/btrfs/inode.c:7908
WARNING: at fs/btrfs/inode.c:7909
WARNING: at fs/btrfs/inode.c:7911
WARNING: at fs/btrfs/extent-tree.c:4510
WARNING: at fs/btrfs/extent-tree.c:4511
This problem was introduced by the patch "Btrfs: fix deadlock due
to unsubmitted". In this patch, there are two bugs which caused
the above problem.
The 1st one is a off-by-one bug, if the DIO write return 0, it is
also a short write, we need release the reserved space for it. But
we didn't do it in that patch. Fix it by change "ret > 0" to
"ret >= 0".
The 2nd one is ->outstanding_extents was increased twice when
a short write happened. As we know, ->outstanding_extents is
a counter to keep track of the number of extent items we may
use duo to delalloc, when we reserve the free space for a
delalloc write, we assume that the write will introduce just
one extent item, so we increase ->outstanding_extents by 1 at
that time. And then we will increase it every time we split the
write, it is done at the beginning of btrfs_get_blocks_direct().
So when a short write happens, we needn't increase
->outstanding_extents again. But this patch done.
In order to fix the 2nd problem, I re-write the logic for
->outstanding_extents operation. We don't increase it at the
beginning of btrfs_get_blocks_direct(), instead, we just
increase it when the split actually happens.
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This comes from one of btrfs's project ideas,
As we defragment files, we break any sharing from other snapshots.
The balancing code will preserve the sharing, and defrag needs to grow this
as well.
Now we're able to fill the blank with this patch, in which we make full use of
backref walking stuff.
Here is the basic idea,
o set the writeback ranges started by defragment with flag EXTENT_DEFRAG
o at endio, after we finish updating fs tree, we use backref walking to find
all parents of the ranges and re-link them with the new COWed file layout by
adding corresponding backrefs.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Very large fallocate requests are cpu bound and result in extents with a
repeating pattern of ever decreasing size:
$ time fallocate -l 1T file
real 0m13.039s
( an excerpt of the extents from btrfs-debug-tree: )
prealloc data disk byte 1536292564992 nr 397312
prealloc data disk byte 1536292962304 nr 196608
prealloc data disk byte 1536293158912 nr 98304
prealloc data disk byte 1536293257216 nr 49152
prealloc data disk byte 1536293306368 nr 24576
prealloc data disk byte 1536293330944 nr 12288
prealloc data disk byte 1536293343232 nr 8192
prealloc data disk byte 1536293351424 nr 4096
prealloc data disk byte 1536293355520 nr 4096
prealloc data disk byte 1536293359616 nr 4096
The excessive cpu use comes from __btrfs_prealloc_file_range() trying to
allocate the entire remaining size after each extent is allocated.
btrfs_reserve_extent() repeatedly cuts this requested size in half until
it gets down to the size that the allocators can return. We limit the
problem for now by capping each reservation at 256 meg.
The small extents come from a masking bug when decreasing the requested
reservation size. The high 32bits are cleared and the remaining low
bits might happen to reserve a small size. Fix this by using
round_down() which properly casts the mask.
After these fixes huge fallocate requests are fast and result in nice
large extents:
$ time fallocate -l 1T file
real 0m0.082s
prealloc data disk byte 1112425889792 nr 268435456
prealloc data disk byte 1112694325248 nr 268435456
prealloc data disk byte 1112962760704 nr 268435456
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Zach Brown <zab@redhat.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Right now inode cache inode is treated as the same as space cache
inode, ie. keep inode in memory till putting super.
But this leads to an awkward situation.
If we're going to delete a snapshot/subvolume, btrfs will not
actually delete it and return free space, but will add it to dead
roots list until the last inode on this snap/subvol being destroyed.
Then we'll fetch deleted roots and cleanup them via cleaner thread.
So here is the problem, if we enable inode cache option, each
snap/subvol has a cached inode which is used to store inode allcation
information. And this cache inode will be kept in memory, as the above
said. So with inode cache, snap/subvol can only be added into
dead roots list during freeing roots stage in umount, so that we can
ONLY get space back after another remount(we cleanup dead roots on mount).
But the real thing is we'll no more use the snap/subvol if we mark it
deleted, so we can safely iput its cache inode when we delete snap/subvol.
Another thing is that we need to change the rules of droping inode, we
don't keep snap/subvol's cache inode in memory till end so that we can
add snap/subvol into dead roots list in time.
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This idea is from ext4. By this patch, we can make the dio write parallel,
and improve the performance. But because we can not update isize without
i_mutex, the unlocked dio write just can be done in front of the EOF.
We needn't worry about the race between dio write and truncate, because the
truncate need wait untill all the dio write end.
And we also needn't worry about the race between dio write and punch hole,
because we have extent lock to protect our operation.
I ran fio to test the performance of this feature.
== Hardware ==
CPU: Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz
Mem: 2GB
SSD: Intel X25-M 120GB (Test Partition: 60GB)
== config file ==
[global]
ioengine=psync
direct=1
bs=4k
size=32G
runtime=60
directory=/mnt/btrfs/
filename=testfile
group_reporting
thread
[file1]
numjobs=1 # 2 4
rw=randwrite
== result (KBps) ==
write 1 2 4
lock 24936 24738 24726
nolock 24962 30866 32101
== result (iops) ==
write 1 2 4
lock 6234 6184 6181
nolock 6240 7716 8025
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Currently, we can do unlocked dio reads, but the following race
is possible:
dio_read_task truncate_task
->btrfs_setattr()
->btrfs_direct_IO
->__blockdev_direct_IO
->btrfs_get_block
->btrfs_truncate()
#alloc truncated blocks
#to other inode
->submit_io()
#INFORMATION LEAK
In order to avoid this problem, we must serialize unlocked dio reads with
truncate. There are two approaches:
- use extent lock to protect the extent that we truncate
- use inode_dio_wait() to make sure the truncating task will wait for
the read DIO.
If we use the 1st one, we will meet the endless truncation problem due to
the nonlocked read DIO after we implement the nonlocked write DIO. It is
because we still need invoke inode_dio_wait() avoid the race between write
DIO and truncation. By that time, we have to introduce
btrfs_inode_{block, resume}_nolock_dio()
again. That is we have to implement this patch again, so I choose the 2nd
way to fix the problem.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The deadlock problem happened when running fsstress(a test program in LTP).
Steps to reproduce:
# mkfs.btrfs -b 100M <partition>
# mount <partition> <mnt>
# <Path>/fsstress -p 3 -n 10000000 -d <mnt>
The reason is:
btrfs_direct_IO()
|->do_direct_IO()
|->get_page()
|->get_blocks()
| |->btrfs_delalloc_resereve_space()
| |->btrfs_add_ordered_extent() ------- Add a new ordered extent
|->dio_send_cur_page(page0) -------------- We didn't submit bio here
|->get_page()
|->get_blocks()
|->btrfs_delalloc_resereve_space()
|->flush_space()
|->btrfs_start_ordered_extent()
|->wait_event() ---------- Wait the completion of
the ordered extent that is
mentioned above
But because we didn't submit the bio that is mentioned above, the ordered
extent can not complete, we would wait for its completion forever.
There are two methods which can fix this deadlock problem:
1. submit the bio before we invoke get_blocks()
2. reserve the space before we do dio
Though the 1st is the simplest way, we need modify the code of VFS, and it
is likely to break contiguous requests, and introduce performance regression
for the other filesystems.
So we have to choose the 2nd way.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I noticed we were getting lots of warnings with xfstest 83 because we have
reservations outstanding. This is because we moved the orphan add outside
of the truncate, but we don't actually cleanup our reservation if something
fails. This fixes the problem and I no longer see warnings. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Sometimes xfstest 83 will fail to remount the scratch device because we've
gotten ourselves so full that we cannot cleanup the orphan items. In this
case check to see if we're doing the orphan cleanup and if we are allow us
to steal our reservation from the global block rsv. With this patch I've
not been able to reproduce the failed mount problem. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
I noticed we would deadlock if we aborted a transaction while doing
compressed io. This is because we don't unlock our pages if something goes
horribly wrong. To fix this we need to make sure that we call
extent_clear_unlock_delalloc in order to unlock all the pages. If we have
to cow in the async submission thread we need to make sure to unlock our
locked_page as the cow error path will not unlock the locked page as it
depends on the caller to unlock that page. With this patch we no longer
deadlock on the page lock when we have an aborted transaction. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Dave sent me a panic where we were doing the orphan cleanup and panic'ed
trying to release our reservation from the orphan block rsv. The reason for
this is because our orphan block rsv had been free'd out from underneath us
because the transaction commit found that there were no orphan inodes
according to its count and decided to free it. This is incorrect so make
sure we inc the orphan inodes count so the accounting is all done properly.
This would also cause the warning in the orphan commit code normally if you
had any orphans to cleanup as they would only decrement the orphan count so
you'd get a negative orphan count which could cause problems during runtime.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
When a transaction aborts or there's an EIO on an ordered extent or any
error really we will not free up the space we reserved for this ordered
extent. This results in warnings from the block group cache cleanup in the
case of a transaction abort, or leaking space in the case of EIO on an
ordered extent. Fix this up by free'ing the reserved space if we have an
error at all trying to complete an ordered extent. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
We need not use a global lock to protect the delalloc_bytes of the
inode, just use its own lock. In this way, we can reduce the lock
contention and ->delalloc_lock will just protect delalloc inode
list.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
