We can run into a problem where we find an eb for our existing page already on
the radix tree but it has a ref count of 0. It hasn't yet been removed by RCU
yet so this can cause issues where we will use the EB after free. So do
atomic_inc_not_zero on the exists->refs and if it is zero just do
synchronize_rcu() and try again. We won't have to worry about new allocators
coming in since they will block on the page lock at this point. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
We spend a lot of time looking up extent buffers from pages when we could just
store the pointer to the eb the page is associated with in page->private. This
patch does just that, and it makes things a little simpler and reduces a bit of
CPU overhead involved with doing metadata IO. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
A few years ago the btrfs code to support blocks lager than
the page size was disabled to fix a few corner cases in the
page cache handling. This fixes the code to properly support
large metadata blocks again.
Since current kernels will crash early and often with larger
metadata blocks, this adds an incompat bit so that older kernels
can't mount it.
This also does away with different blocksizes for nodes and leaves.
You get a single block size for all tree blocks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We have been passing nothing but (u64)-1 to find_free_extent for search_end in
all of the callers, so it's completely useless, and we've always been passing 0
in as search_start, so just remove them as function arguments and move
search_start into find_free_extent. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
This is a relic from before we had the disk space cache and it was to make
bootup times when you had btrfs as root not be so damned slow. Now that we have
the disk space cache this isn't a problem anymore and really having this code
casues uneeded fragmentation and complexity, so just remove it. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
When a filesystem got aborted due do error, transaction_kthread() will
busyloop. Fix it by going to sleep in that case as well. Maybe we should
just stop transaction_kthread() when filesystem is aborted but that would be
more complex.
Signed-off-by: Jan Kara <jack@suse.cz>
btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs currently handles most errors with BUG_ON. This patch is a work-in-
progress but aims to handle most errors other than internal logic
errors and ENOMEM more gracefully.
This iteration prevents most crashes but can run into lockups with
the page lock on occasion when the timing "works out."
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_alloc_chunk() unconditionally BUGs on any error returned from
__finish_chunk_alloc() so there's no need for two BUG_ON lines. Remove the
one from __finish_chunk_alloc().
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
We BUG_ON() error from add_extent_mapping(), but that error looks pretty
easy to bubble back up - as far as I can tell there have not been any
permanent modifications to fs state at that point.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
The only caller of btrfs_alloc_dev_extent() is __btrfs_alloc_chunk() which
already bugs on any error returned. We can remove the BUG_ON's in
btrfs_alloc_dev_extent() then since __btrfs_alloc_chunk() will "catch" them
anyway.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
balace_level() seems to deal with missing tree nodes by BUG_ON(). Instead,
we can easily just set the file system readonly and bubble -EROFS back up
the stack.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
__btrfs_cow_block(), the only caller of update_ref_for_cow() will BUG_ON()
any error return. Instead, we can go read-only fs as update_ref_for_cow()
manipulates disk data in a way which doesn't look like it's easily rolled
back.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
update_ref_for_cow() will BUG_ON() after it's call to
btrfs_lookup_extent_info() if no existing references are found. Since refs
are computed directly from disk, this should be treated as a corruption
instead of a logic error.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
All callers of __finish_chunk_alloc() BUG_ON() return value, so it's trivial
for us to always bubble up any errors caught in __finish_chunk_alloc() to be
caught there.
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Unfortunately it isn't enough to just exit here - the kzalloc() happens in a
loop and the allocated items are added to a linked list whose head is passed
in from the caller.
To fix the BUG_ON() and also provide the semantic that the list passed in is
only modified on success, I create function-local temporary list that we add
items too. If no error is met, that list is spliced to the callers at the
end of the function. Otherwise the list will be walked and all items freed
before the error value is returned.
I did a simple test on this patch by forcing an error at the kzalloc() point
and verifying that when this hits (git clone seemed to exercise this), the
function throws the proper error. Unfortunately but predictably, we later
hit a BUG_ON(ret) type line that still hasn't been fixed up ;)
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The only caller of update_ref_for_cow() is __btrfs_cow_block() which was
originally ignoring any return values. update_ref_for_cow() however doesn't
look like a candidate to become a void function - there are a few places
where errors can occur.
So instead I changed update_ref_for_cow() to bubble all errors up (instead
of BUG_ON). __btrfs_cow_block() was then updated to catch and BUG_ON() any
errors from update_ref_for_cow(). The end effect is that we have no change
in behavior, but about 8 different places where a BUG_ON(ret) was removed.
Obviously a future patch will have to address the BUG_ON() in
__btrfs_cow_block().
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
This is called from only one place - create_subvol() which passes errors
safely back out to it's caller, btrfs_mksubvol where they are handled.
Additionally, btrfs_create_subvol_root() itself bug's needlessly from error
return of btrfs_update_inode(). Since create_subvol() was fixed to catch
errors we can bubble this one up too.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Commit cb1b69f4 (Btrfs: forced readonly when btrfs_drop_snapshot() fails)
made btrfs_drop_snapshot return void because there were no callers checking
the return value. That is the wrong order to handle error propogation since
the caller will have no idea that an error has occured and continue on
as if nothing went wrong.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
set_extent_bit can do exclusive locking but only when called by lock_extent*,
Drop the exclusive bits argument except when called by lock_extent.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
lock_extent and unlock_extent are always called with GFP_NOFS, drop the
argument and use GFP_NOFS consistently.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
This patch pushes kmalloc errors up to the caller and BUGs in the caller.
The BUG_ON for duplicate reloc tree root insertion is replaced with a
panic explaining the issue.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
This pushes failures from the submit_bio_hook callbacks,
btrfs_submit_bio_hook and btree_submit_bio_hook into the callers, including
callers of submit_one_bio where it catches the failures with BUG_ON.
It also pushes up through the ->readpage_io_failed_hook to
end_bio_extent_writepage where the error is already caught with BUG_ON.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
In submit_extent_page, there's a visually noisy if statement that, in
the midst of other conditions, does the tree dependency for tree->ops
and tree->ops->merge_bio_hook before calling it, and then another
condition afterwards. If an error is returned from merge_bio_hook,
there's no way to catch it. It's considered a routine "1" return
value instead of a failure.
This patch factors out the dependency check into a new local merge_bio
routine and BUG's on an error. The if statement is less noisy as a side-
effect.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_submit_bio_hook currently calls btrfs_bio_wq_end_io in either case
of an if statement that determines one of the arguments.
This patch moves the function call outside of the if statement and uses it
to only determine the different argument. This allows us to catch an
error in one place in a more visually obvious way.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
btrfs_update_root BUG's when it can't alloc a path, yet it can recover
from a search error. This patch returns -ENOMEM instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
find_and_setup_root BUGs when it encounters an error from
btrfs_find_last_root, which can occur if a path can't be allocated.
This patch pushes it up to its callers where it is already handled.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
There is only one caller of clear_extent_bit that checks the return value
and it only checks if it's negative. Since there are no users of the
returned bits functionality of clear_extent_bit, stop returning it
and avoid complicating error handling.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The only error condition in clean_tree_block is an accounting bug.
Returning without modifying dirty_metadata_bytes and as if the cleaning
as been performed may cause problems later so it should panic instead.
It should probably be a BUG_ON but we have btrfs_panic now.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Correctness fix: The kfree calls in the add_delayed_* functions free
the node that's passed into it, but the node is a member of another
structure. It works because it's always the first member of the
containing structure, but it should really be using the containing
structure itself.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The ordered data and relocation trees have BUG_ONs to protect against
bad tree operations.
This patch replaces them with a panic that will report the problem.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
The *_state functions can only return 0 or -EEXIST. This patch addresses
the cases where those functions returning -EEXIST represent a locking
failure. It handles them by panicking with an appropriate error message.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
As part of the effort to eliminate BUG_ON as an error handling
technique, we need to determine which errors are actual logic errors,
which are on-disk corruption, and which are normal runtime errors
e.g. -ENOMEM.
Annotating these error cases is helpful to understand and report them.
This patch adds a btrfs_panic() routine that will either panic
or BUG depending on the new -ofatal_errors={panic,bug} mount option.
Since there are still so many BUG_ONs, it defaults to BUG for now but I
expect that to change once the error handling effort has made
significant progress.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Pull vfs pile 1 from Al Viro:
"This is _not_ all; in particular, Miklos' and Jan's stuff is not there
yet."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits)
ext4: initialization of ext4_li_mtx needs to be done earlier
debugfs-related mode_t whack-a-mole
hfsplus: add an ioctl to bless files
hfsplus: change finder_info to u32
hfsplus: initialise userflags
qnx4: new helper - try_extent()
qnx4: get rid of qnx4_bread/qnx4_getblk
take removal of PF_FORKNOEXEC to flush_old_exec()
trim includes in inode.c
um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it
um: embed ->stub_pages[] into mmu_context
gadgetfs: list_for_each_safe() misuse
ocfs2: fix leaks on failure exits in module_init
ecryptfs: make register_filesystem() the last potential failure exit
ntfs: forgets to unregister sysctls on register_filesystem() failure
logfs: missing cleanup on register_filesystem() failure
jfs: mising cleanup on register_filesystem() failure
make configfs_pin_fs() return root dentry on success
configfs: configfs_create_dir() has parent dentry in dentry->d_parent
configfs: sanitize configfs_create()
...
Pull kmap_atomic cleanup from Cong Wang.
It's been in -next for a long time, and it gets rid of the (no longer
used) second argument to k[un]map_atomic().
Fix up a few trivial conflicts in various drivers, and do an "evil
merge" to catch some new uses that have come in since Cong's tree.
* 'kmap_atomic' of git://github.com/congwang/linux: (59 commits)
feature-removal-schedule.txt: schedule the deprecated form of kmap_atomic() for removal
highmem: kill all __kmap_atomic() [swarren@nvidia.com: highmem: Fix ARM build break due to __kmap_atomic rename]
drbd: remove the second argument of k[un]map_atomic()
zcache: remove the second argument of k[un]map_atomic()
gma500: remove the second argument of k[un]map_atomic()
dm: remove the second argument of k[un]map_atomic()
tomoyo: remove the second argument of k[un]map_atomic()
sunrpc: remove the second argument of k[un]map_atomic()
rds: remove the second argument of k[un]map_atomic()
net: remove the second argument of k[un]map_atomic()
mm: remove the second argument of k[un]map_atomic()
lib: remove the second argument of k[un]map_atomic()
power: remove the second argument of k[un]map_atomic()
kdb: remove the second argument of k[un]map_atomic()
udf: remove the second argument of k[un]map_atomic()
ubifs: remove the second argument of k[un]map_atomic()
squashfs: remove the second argument of k[un]map_atomic()
reiserfs: remove the second argument of k[un]map_atomic()
ocfs2: remove the second argument of k[un]map_atomic()
ntfs: remove the second argument of k[un]map_atomic()
...
Pull trivial tree from Jiri Kosina:
"It's indeed trivial -- mostly documentation updates and a bunch of
typo fixes from Masanari.
There are also several linux/version.h include removals from Jesper."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (101 commits)
kcore: fix spelling in read_kcore() comment
constify struct pci_dev * in obvious cases
Revert "char: Fix typo in viotape.c"
init: fix wording error in mm_init comment
usb: gadget: Kconfig: fix typo for 'different'
Revert "power, max8998: Include linux/module.h just once in drivers/power/max8998_charger.c"
writeback: fix fn name in writeback_inodes_sb_nr_if_idle() comment header
writeback: fix typo in the writeback_control comment
Documentation: Fix multiple typo in Documentation
tpm_tis: fix tis_lock with respect to RCU
Revert "media: Fix typo in mixer_drv.c and hdmi_drv.c"
Doc: Update numastat.txt
qla4xxx: Add missing spaces to error messages
compiler.h: Fix typo
security: struct security_operations kerneldoc fix
Documentation: broken URL in libata.tmpl
Documentation: broken URL in filesystems.tmpl
mtd: simplify return logic in do_map_probe()
mm: fix comment typo of truncate_inode_pages_range
power: bq27x00: Fix typos in comment
...
Pull btrfs updates from Chris Mason:
"I have two additional and btrfs fixes in my for-linus branch. One is
a casting error that leads to memory corruption on i386 during scrub,
and the other fixes a corner case in the backref walking code (also
triggered by scrub)."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix casting error in scrub reada code
btrfs: fix locking issues in find_parent_nodes()
The reada code from scrub was casting down a u64 to
an unsigned long so it could insert it into a radix tree.
What it really wanted to do was cast down the result of a shift, instead
of casting down the u64. The bug resulted in trying to insert our
reada struct into the wrong place, which caused soft lockups and other
problems.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
- We might unlock head->mutex while it was not locked
- We might leave the function without unlocking delayed_refs->lock
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Quoth Chris:
"This is later than I wanted because I got backed up running through
btrfs bugs from the Oracle QA teams. But they are all bug fixes that
we've queued and tested since rc1.
Nothing in particular stands out, this just reflects bug fixing and QA
done in parallel by all the btrfs developers. The most user visible
of these is:
Btrfs: clear the extent uptodate bits during parent transid failures
Because that helps deal with out of date drives (say an iscsi disk
that has gone away and come back). The old code wasn't always
properly retrying the other mirror for this type of failure."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits)
Btrfs: fix compiler warnings on 32 bit systems
Btrfs: increase the global block reserve estimates
Btrfs: clear the extent uptodate bits during parent transid failures
Btrfs: add extra sanity checks on the path names in btrfs_mksubvol
Btrfs: make sure we update latest_bdev
Btrfs: improve error handling for btrfs_insert_dir_item callers
Btrfs: be less strict on finding next node in clear_extent_bit
Btrfs: fix a bug on overcommit stuff
Btrfs: kick out redundant stuff in convert_extent_bit
Btrfs: skip states when they does not contain bits to clear
Btrfs: check return value of lookup_extent_mapping() correctly
Btrfs: fix deadlock on page lock when doing auto-defragment
Btrfs: fix return value check of extent_io_ops
btrfs: honor umask when creating subvol root
btrfs: silence warning in raid array setup
btrfs: fix structs where bitfields and spinlock/atomic share 8B word
btrfs: delalloc for page dirtied out-of-band in fixup worker
Btrfs: fix memory leak in load_free_space_cache()
btrfs: don't check DUP chunks twice
Btrfs: fix trim 0 bytes after a device delete
...
When doing IO with large amounts of data fragmentation, the global block
reserve calulations are too low. This increases them to avoid
ENOSPC crashes.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If btrfs reads a block and finds a parent transid mismatch, it clears
the uptodate flags on the extent buffer, and the pages inside it. But
we only clear the uptodate bits in the state tree if the block straddles
more than one page.
This is from an old optimization from to reduce contention on the extent
state tree. But it is buggy because the code that retries a read from
a different copy of the block is going to find the uptodate state bits
set and skip the IO.
The end result of the bug is that we'll never actually read the good
copy (if there is one).
The fix here is to always clear the uptodate state bits, which is safe
because this code is only called when the parent transid fails.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we are setting up the mount, we close all the
devices that were not actually part of the metadata we found.
But, we don't make sure that one of those devices wasn't
fs_devices->latest_bdev, which means we can do a use after free
on the one we closed.
This updates latest_bdev as it goes.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This allows us to gracefully continue if we aren't able to insert
directory items, both for normal files/dirs and snapshots.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Clearing a range's bits is different with setting them, since we don't
need to touch them when states do not contain bits we want.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
When I ran xfstests circularly on a auto-defragment btrfs, the deadlock
happened.
Steps to reproduce:
[tty0]
# export MOUNT_OPTIONS="-o autodefrag"
# export TEST_DEV=<partition1>
# export TEST_DIR=<mountpoint1>
# export SCRATCH_DEV=<partition2>
# export SCRATCH_MNT=<mountpoint2>
# while [ 1 ]
> do
> ./check 091 127 263
> sleep 1
> done
[tty1]
# while [ 1 ]
> do
> echo 3 > /proc/sys/vm/drop_caches
> done
Several hours later, the test processes will hang on, and the deadlock will
happen on page lock.
The reason is that:
Auto defrag task Flush thread Test task
btrfs_writepages()
add ordered extent
(including page 1, 2)
set page 1 writeback
set page 2 writeback
endio_fn()
end page 2 writeback
release page 2
lock page 1
alloc and lock page 2
page 2 is not uptodate
btrfs_readpage()
start ordered extent()
btrfs_writepages()
try to lock page 1
so deadlock happens.
Fix this bug by unlocking the page which is in writeback, and re-locking it
after the writeback end.
Signed-off-by: Miao Xie <miax@cn.fujitsu.com>
Raid array setup code creates an extent buffer in an usual way. When the
PAGE_CACHE_SIZE is > super block size, the extent pages are not marked
up-to-date, which triggers a WARN_ON in the following
write_extent_buffer call. Add an explicit up-to-date call to silence the
warning.
Signed-off-by: David Sterba <dsterba@suse.cz>
On ia64, powerpc64 and sparc64 the bitfield is modified through a RMW cycle and current
gcc rewrites the adjacent 4B word, which in case of a spinlock or atomic has
disaterous effect.
https://lkml.org/lkml/2012/2/1/220
Signed-off-by: David Sterba <dsterba@suse.cz>
We encountered an issue that was easily observable on s/390 systems but
could really happen anywhere. The timing just seemed to hit reliably
on s/390 with limited memory.
The gist is that when an unexpected set_page_dirty() happened, we'd
run into the BUG() in btrfs_writepage_fixup_worker since it wasn't
properly set up for delalloc.
This patch does the following:
- Performs the missing delalloc in the fixup worker
- Allow the start hook to return -EBUSY which informs __extent_writepage
that it should mark the page skipped and not to redirty it. This is
required since the fixup worker can fail with -ENOSPC and the page
will have already been redirtied. That causes an Oops in
drop_outstanding_extents later. Retrying the fixup worker could
lead to an infinite loop. Deferring the page redirty also saves us
some cycles since the page would be stuck in a resubmit-redirty loop
until the fixup worker completes. It's not harmful, just wasteful.
- If the fixup worker fails, we mark the page and mapping as errored,
and end the writeback, similar to what we would do had the page
actually been submitted to writeback.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Because scrub enumerates the dev extent tree to find the chunks to scrub,
it currently finds each DUP chunk twice and also scrubs it twice. This
patch makes sure that scrub_chunk only checks that part of the chunk the
dev extent has been found for. This only changes the behaviour for DUP
chunks.
Reported-and-tested-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Arne Jansen <sensille@gmx.net>
A user reported a bug of btrfs's trim, that is we will trim 0 bytes
after a device delete.
The reproducer:
$ mkfs.btrfs disk1
$ mkfs.btrfs disk2
$ mount disk1 /mnt
$ fstrim -v /mnt
$ btrfs device add disk2 /mnt
$ btrfs device del disk1 /mnt
$ fstrim -v /mnt
This is because after we delete the device, the block group may start from
a non-zero place, which will confuse trim to discard nothing.
Reported-by: Lutz Euler <lutz.euler@freenet.de>
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Given that ENXIO only means "offset beyond EOF" for either SEEK_DATA or SEEK_HOLE inquiry
in a desired file range, so we should return the internal error unchanged if btrfs_get_extent_fiemap()
call failed, rather than ENXIO.
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
inode_ref_info() returns 1 when the element wasn't found and < 0 on error,
just like btrfs_search_slot(). In iref_to_path() it's an error when the
inode ref can't be found, thus we return ERR_PTR(ret) in that case. In order
to avoid ERR_PTR(1), we now set ret to -ENOENT in that case.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Gracefully fail when trying to mount a BTRFS file system that has a
sectorsize smaller than PAGE_SIZE.
On PPC it is possible to build a FS while using a 4k PAGE_SIZE kernel
then boot into a 64K PAGE_SIZE kernel. Presently open_ctree fails in an
endless loop and hangs the machine in this situation.
My debugging has show this Sector size < Page size to be a non trivial
situation and a graceful exit from the situation would be nice for the
time being.
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
btrfs_fallocate tries to allocate space only if ranges in the file don't
already exist. But the enospc checks it does are not allowed with
extents locked.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix reservations in btrfs_page_mkwrite
Btrfs: advance window_start if we're using a bitmap
btrfs: mask out gfp flags in releasepage
Btrfs: fix enospc error caused by wrong checks of the chunk
Btrfs: do not defrag a file partially
Btrfs: fix warning for 32-bit build of fs/btrfs/check-integrity.c
Btrfs: use cluster->window_start when allocating from a cluster bitmap
Btrfs: Check for NULL page in extent_range_uptodate
btrfs: Fix busyloops in transaction waiting code
Btrfs: make sure a bitmap has enough bytes
Btrfs: fix uninit warning in backref.c
Josef fixed btrfs_page_mkwrite to properly release reserved
extents if there was an error. But if we fail to get a reservation
and we fail to dirty the inode (for ENOSPC reasons), we'll end up
trying to release a reservation we never had.
This makes sure we only release if we were able to reserve.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If we span a long area in a bitmap we could end up taking a lot of time
searching to the next free area if we're searching from the original
window_start, so advance window_start in order to make sure we don't do any
superficial searching. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btree_releasepage is a callback and can be passed unknown gfp flags and then
they may end up in kmem_cache_alloc called from alloc_extent_state, slab
allocator will BUG_ON when there is HIGHMEM or DMA32 flag set.
This may happen when btrfs is mounted from a loop device, which masks out
__GFP_IO flag. The check in try_release_extent_state
3399 if ((mask & GFP_NOFS) == GFP_NOFS)
3400 mask = GFP_NOFS;
will not work and passes unfiltered flags further resulting in crash at
mm/slab.c:2963
[<000000000024ae4c>] cache_alloc_refill+0x3b4/0x5c8
[<000000000024c810>] kmem_cache_alloc+0x204/0x294
[<00000000001fd3c2>] mempool_alloc+0x52/0x170
[<000003c000ced0b0>] alloc_extent_state+0x40/0xd4 [btrfs]
[<000003c000cee5ae>] __clear_extent_bit+0x38a/0x4cc [btrfs]
[<000003c000cee78c>] try_release_extent_state+0x9c/0xd4 [btrfs]
[<000003c000cc4c66>] btree_releasepage+0x7e/0xd0 [btrfs]
[<0000000000210d84>] shrink_page_list+0x6a0/0x724
[<0000000000211394>] shrink_inactive_list+0x230/0x578
[<0000000000211bb8>] shrink_list+0x6c/0x120
[<0000000000211e4e>] shrink_zone+0x1e2/0x228
[<0000000000211f24>] shrink_zones+0x90/0x254
[<0000000000213410>] do_try_to_free_pages+0xac/0x420
[<0000000000213ae0>] try_to_free_pages+0x13c/0x1b0
[<0000000000204e6c>] __alloc_pages_nodemask+0x5b4/0x9a8
[<00000000001fb04a>] grab_cache_page_write_begin+0x7e/0xe8
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When we did sysbench test for inline files, enospc error happened easily though
there was lots of free disk space which could be allocated for new chunks.
Reproduce steps:
# mkfs.btrfs -b $((2 * 1024 * 1024 * 1024)) <test partition>
# mount <test partition> /mnt
# ulimit -n 102400
# cd /mnt
# sysbench --num-threads=1 --test=fileio --file-num=81920 \
> --file-total-size=80M --file-block-size=1K --file-io-mode=sync \
> --file-test-mode=seqwr prepare
# sysbench --num-threads=1 --test=fileio --file-num=81920 \
> --file-total-size=80M --file-block-size=1K --file-io-mode=sync \
> --file-test-mode=seqwr run
<soon later, BUG_ON() was triggered by enospc error>
The reason of this bug is:
Now, we can reserve space which is larger than the free space in the chunks if
we have enough free disk space which can be used for new chunks. By this way,
the space allocator should allocate a new chunk by force if there is no free
space in the free space cache. But there are two wrong checks which break this
operation.
One is
if (ret == -ENOSPC && num_bytes > min_alloc_size)
in btrfs_reserve_extent(), it is wrong, we should try to allocate a new chunk
even we fail to allocate free space by minimum allocable size.
The other is
if (space_info->force_alloc)
force = space_info->force_alloc;
in do_chunk_alloc(). It makes the allocator ignore CHUNK_ALLOC_FORCE If someone
sets ->force_alloc to CHUNK_ALLOC_LIMITED, and makes the enospc error happen.
Fix these two wrong checks. Especially the second one, we fix it by changing
the value of CHUNK_ALLOC_LIMITED and CHUNK_ALLOC_FORCE, and make
CHUNK_ALLOC_FORCE greater than CHUNK_ALLOC_LIMITED since CHUNK_ALLOC_FORCE has
higher priority. And if the value which is passed in by the caller is greater
than ->force_alloc, use the passed value.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
xfstests 218 complains that btrfs defrags a file partially:
After: 1
Write backwards sync, but contiguous - should defrag to 1 extent
Before: 10
-After: 1
+After: 2
To fix this, we need to set max_to_defrag count properly.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There have been 4 warnings on 32-bit build, they are herewith fixed.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We specifically set window_start in the cluster struct to indicate where the
cluster starts in a bitmap, but we've been using min_start to indicate where
we're searching from. This is usually the start of the blockgroup, so
essentially means we're constantly searching from the start of any bitmap we
find, which completely negates all the trouble we go to in order to setup a
cluster. So start using window_start to make sure we actually use the area we
found. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A user has encountered a NULL pointer kernel oops in btrfs when
encountering media errors. The problem has been identified
as an unhandled NULL pointer returned from find_get_page().
This modification simply checks for a NULL page, and returns
with an error if found (the extent_range_uptodate() function
returns 1 on errors).
After testing this patch, the user reported that the error with
the NULL pointer oops was solved. However, there is still a
remaining problem with a thread becoming stuck in
wait_on_page_locked(page) in the read_extent_buffer_pages(...)
function in extent_io.c
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
wait_on_page_locked(page);
if (!PageUptodate(page))
ret = -EIO;
}
This patch leaves the issue with the locked page yet to be resolved.
Signed-off-by: Mitch Harder <mitch.harder@sabayonlinux.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
wait_log_commit() and wait_for_writer() were using slightly different
conditions for deciding whether they should call schedule() and whether they
should continue in the wait loop. Thus it could happen that we busylooped when
the first condition was not true while the second one was. That is burning CPU
cycles needlessly and is deadly on UP machines...
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We have only been checking for min_bytes available in bitmap entries, but we
won't successfully setup a bitmap cluster unless it has at least bytes in the
bitmap, so in the common case min_bytes is 4k and we want something like 2MB, so
if there are a bunch of bitmap entries with less than 2mb's in them, we'll
search all them anyway, which is suboptimal. Fix this check. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Added initialization with the declaration of ret. It isn't set later on the
switch-default branch (which should never be taken).
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'btrfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
btrfs: take allocation of ->tree_root into open_ctree()
btrfs: let ->s_fs_info point to fs_info, not root...
btrfs: consolidate failure exits in btrfs_mount() a bit
btrfs: make free_fs_info() call ->kill_sb() unconditional
btrfs: merge free_fs_info() calls on fill_super failures
btrfs: kill pointless reassignment of ->s_fs_info in btrfs_fill_super()
btrfs: make open_ctree() return int
btrfs: sanitizing ->fs_info, part 5
btrfs: sanitizing ->fs_info, part 4
btrfs: sanitizing ->fs_info, part 3
btrfs: sanitizing ->fs_info, part 2
btrfs: sanitizing ->fs_info, part 1
btrfs: fix a deadlock in btrfs_scan_one_device()
btrfs: fix mount/umount race
btrfs: get ->kill_sb() of its own
btrfs: preparation to fixing mount/umount race
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (62 commits)
Btrfs: use larger system chunks
Btrfs: add a delalloc mutex to inodes for delalloc reservations
Btrfs: space leak tracepoints
Btrfs: protect orphan block rsv with spin_lock
Btrfs: add allocator tracepoints
Btrfs: don't call btrfs_throttle in file write
Btrfs: release space on error in page_mkwrite
Btrfs: fix btrfsck error 400 when truncating a compressed
Btrfs: do not use btrfs_end_transaction_throttle everywhere
Btrfs: add balance progress reporting
Btrfs: allow for resuming restriper after it was paused
Btrfs: allow for canceling restriper
Btrfs: allow for pausing restriper
Btrfs: add skip_balance mount option
Btrfs: recover balance on mount
Btrfs: save balance parameters to disk
Btrfs: soft profile changing mode (aka soft convert)
Btrfs: implement online profile changing
Btrfs: do not reduce profile in do_chunk_alloc()
Btrfs: virtual address space subset filter
...
Fix up trivial conflict in fs/btrfs/ioctl.c due to the use of the new
mnt_drop_write_file() helper.
system chunks by default are very small. This makes them slightly
larger and also fixes the conditional checks to make sure we don't
allocate a billion of them at once.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
I was using i_mutex for this, but we're getting bogus lockdep warnings by doing
that and theres no real way to get rid of those, so just stop using i_mutex to
protect delalloc metadata reservations and use a delalloc mutex instead. This
shouldn't be contended often at all, only if you are writing and mmap writing to
the file at the same time. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
This in addition to a script in my btrfs-tracing tree will help track down space
leaks when we're getting space left over in block groups on umount. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
We've been seeing warnings coming out of the orphan commit stuff forever from
ceph. Turns out it's because we're racing with checking if the orphan block
reserve is set, because we clear it outside of the spin_lock. So leave the
normal fastpath checks where they are, but take the spin_lock and _recheck_ to
make sure we haven't had an orphan block rsv added in the meantime. Then clear
the root's orphan block rsv and release the lock. With this patch a user said
the warnings went away and they usually showed up pretty soon after he started
ceph. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
I used these tracepoints when figuring out what the cluster stuff was doing, so
add them to mainline in case we need to profile this stuff again. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Btrfs_throttle will make us wait if there is a currently committing transaction
until we can open new transactions, which is ridiculous since we don't actually
start any transactions within the file write path anyway, so all this does is
introduce big latencies if we have a sync/fsync heavy workload going on while
somebody else is trying to do work. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
If updating the inode gave us an ENOSPC we were just returning in page_mkwrite,
which is a problem since we make our reservation right before trying to update
the inode, so fix the out label so that we actually free our reservation.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Reproduce steps:
# mkfs.btrfs /dev/sdb5
# mount /dev/sdb5 -o compress=lzo /mnt
# dd if=/dev/zero of=/mnt/tmpfile bs=128K count=1
# sync
# truncate -s 64K /mnt/tmpfile
root 5 inode 257 errors 400
This is because of the wrong if condition, which is used to check if we should
subtract the bytes of the dropped range from i_blocks/i_bytes of i-node or not.
When we truncate a compressed extent, btrfs substracts the bytes of the whole
extent, it's wrong. We should substract the real size that we truncate, no
matter it is a compressed extent or not. Fix it.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A user reported a problem where things like open with O_CREAT would take up to
30 seconds when he had nfs activity on the same mount. This is because all of
our quick metadata operations, like create, symlink etc all do
btrfs_end_transaction_throttle, which if the transaction is blocked will wait
for the commit to complete before it returns. This adds a ridiculous amount of
latency and isn't really needed. The normal btrfs_end_transaction will mark the
transaction as blocked and wake the transaction kthread up if it thinks the
transaction needs to end (this being in the running out of global reserve space
scenario), and this is all that is really needed since we've already done
everything we're going to do, we just need to return. This should help people
with the latency they were seeing when using synchronous heavy workloads.
Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Recognize BTRFS_BALANCE_RESUME flag passed from userspace. We use the
same heuristics used when recovering balance after a crash to try to
start where we left off last time.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Implement an ioctl for canceling restriper. Currently we wait until
relocation of the current block group is finished, in future this can be
done by triggering a commit. Balance item is deleted and no memory
about the interrupted balance is kept.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Implement an ioctl for pausing restriper. This pauses the relocation,
but balance is still considered to be "in progress": balance item is
not deleted, other volume operations cannot be started, etc. If paused
in the middle of profile changing operation we will continue making
allocations with the target profile.
Add a hook to close_ctree() to pause restriper and free its data
structures on unmount. (It's safe to unmount when restriper is in
"paused" state, we will resume with the same parameters on the next
mount)
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Since restriper kthread starts involuntarily on mount and can suck cpu
and memory bandwidth add a mount option to forcefully skip it. The
restriper in that case hangs around in paused state and can be resumed
from userspace when it's convenient.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
On mount, if balance item is found, resume balance in a separate
kernel thread.
Try to be smart to continue roughly where previous balance (or convert)
was interrupted. For chunk types that were being converted to some
profile we turn on soft convert, in case of a simple balance we turn on
usage filter and relocate only less-than-90%-full chunks of that type.
These are just heuristics but they help quite a bit, and can be improved
in future.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Introduce a new btree objectid for storing balance item. The reason is
to be able to resume restriper after a crash with the same parameters.
Balance item has a very high objectid and goes into tree of tree roots.
The key for the new item is as follows:
[ BTRFS_BALANCE_OBJECTID ; BTRFS_BALANCE_ITEM_KEY ; 0 ]
Older kernels simply ignore it so it's safe to mount with an older
kernel and then go back to the newer one.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
When doing convert from one profile to another if soft mode is on
restriper won't touch chunks that already have the profile we are
converting to. This is useful if e.g. half of the FS was converted
earlier.
The soft mode switch is (like every other filter) per-type. This means
that we can convert for example meta chunks the "hard" way while
converting data chunks selectively with soft switch.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Profile changing is done by launching a balance with
BTRFS_BALANCE_CONVERT bits set and target fields of respective
btrfs_balance_args structs initialized. Profile reducing code in this
case will pick restriper's target profile if it's available instead of
doing a blind reduce. If target profile is not yet available it goes
back to a plain reduce.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Every caller of do_chunk_alloc() feeds it the reduced allocation
profile, so stop trying to reduce it one more time. Instead check the
validity of the passed profile.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Select chunks which have at least one byte located inside a given
[vstart, vend) virtual address space range.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Select chunks which have at least one byte of at least one stripe
located on a device with devid X in a given [pstart,pend) physical
address range.
This filter only works when devid filter is turned on.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This allows to have a separate set of filters for each chunk type
(data,meta,sys). The code however is generic and switch on chunk type
is only done once.
This commit also adds a type filter: it allows to balance for example
meta and system chunks w/o touching data ones.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add basic restriper infrastructure: extended balancing ioctl and all
related ioctl data structures, add data structure for tracking
restriper's state to fs_info, etc. The semantics of the old balancing
ioctl are fully preserved.
Explicitly disallow any volume operations when balance is in progress.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Currently when new chunks are created respective avail_alloc_bits field
is updated to reflect profiles of all chunks present in the system.
However when chunks are removed profile bits are never cleared.
This patch clears profile bit of respective avail_alloc_bits field when
the last chunk with that profile is removed. Restriper needs this to
properly operate when "downgrading".
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Right now on-disk BTRFS_BLOCK_GROUP_* profile bits are used for
avail_{data,metadata,system}_alloc_bits fields, which gather info about
available allocation profiles in the FS. When chunk is created or read
from disk, its profile is OR'ed with the corresponding avail_alloc_bits
field. Since SINGLE is denoted by 0 in the on-disk format, currently
there is no way to tell when such chunks become avaialble. Restriper
needs that information, so add a separate bit for SINGLE profile.
This bit is going to be in-memory only, it should never be written out
to disk, so it's not a disk format change. However to avoid remappings
in future, reserve corresponding on-disk bit.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Chunk's type and profile are encoded in u64 flags field. Introduce
masks to easily access them. Also fix the type of BTRFS_BLOCK_GROUP_*
constants, it should be ULL.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT
mode that avoids writing back pages to backing storage. Async compaction
maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT.
For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is
used.
This avoids sync compaction stalling for an excessive length of time,
particularly when copying files to a USB stick where there might be a
large number of dirty pages backed by a filesystem that does not support
->writepages.
[aarcange@redhat.com: This patch is heavily based on Andrea's work]
[akpm@linux-foundation.org: fix fs/nfs/write.c build]
[akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build]
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Asynchronous compaction is used when allocating transparent hugepages to
avoid blocking for long periods of time. Due to reports of stalling,
there was a debate on disabling synchronous compaction but this severely
impacted allocation success rates. Part of the reason was that many dirty
pages are skipped in asynchronous compaction by the following check;
if (PageDirty(page) && !sync &&
mapping->a_ops->migratepage != migrate_page)
rc = -EBUSY;
This skips over all mapping aops using buffer_migrate_page() even though
it is possible to migrate some of these pages without blocking. This
patch updates the ->migratepage callback with a "sync" parameter. It is
the responsibility of the callback to fail gracefully if migration would
block.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andy Isaacson <adi@hexapodia.org>
Cc: Nai Xia <nai.xia@gmail.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The correct lock order is uuid_mutex -> volume_mutex -> chunk_mutex,
but when we mount a filesystem which has backing seed devices, we have
this lock chain:
open_ctree()
lock(chunk_mutex);
read_chunk_tree();
read_one_dev();
open_seed_devices();
lock(uuid_mutex);
and then we hit a lockdep splat.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
A bug was triggered while using seed device:
# mkfs.btrfs /dev/loop1
# btrfstune -S 1 /dev/loop1
# mount -o /dev/loop1 /mnt
# btrfs dev add /dev/loop2 /mnt
btrfs: block rsv returned -28
------------[ cut here ]------------
WARNING: at fs/btrfs/extent-tree.c:5969 btrfs_alloc_free_block+0x166/0x396 [btrfs]()
...
Call Trace:
...
[<f7b7c31c>] btrfs_cow_block+0x101/0x147 [btrfs]
[<f7b7eaa6>] btrfs_search_slot+0x1b8/0x55f [btrfs]
[<f7b7f844>] btrfs_insert_empty_items+0x42/0x7f [btrfs]
[<f7b7f8c1>] btrfs_insert_item+0x40/0x7e [btrfs]
[<f7b8ac02>] btrfs_make_block_group+0x243/0x2aa [btrfs]
[<f7bb3f53>] __btrfs_alloc_chunk+0x672/0x70e [btrfs]
[<f7bb41ff>] init_first_rw_device+0x77/0x13c [btrfs]
[<f7bb5a62>] btrfs_init_new_device+0x664/0x9fd [btrfs]
[<f7bbb65a>] btrfs_ioctl+0x694/0xdbe [btrfs]
[<c04f55f7>] do_vfs_ioctl+0x496/0x4cc
[<c04f5660>] sys_ioctl+0x33/0x4f
[<c07b9edf>] sysenter_do_call+0x12/0x38
---[ end trace 906adac595facc7d ]---
Since seed device is readonly, there's no usable space in the filesystem.
Afterwards we add a sprout device to it, and the kernel creates a METADATA
block group and a SYSTEM block group where comes free space we can reserve,
but we still get revervation failure because the global block_rsv hasn't
been updated accordingly.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
There are various bugs in block group trimming:
- It may trim from offset smaller than user-specified offset.
- It may trim beyond user-specified range.
- It may leak free space for extents smaller than specified minlen.
- It may truncate the last trimmed extent thus leak free space.
- With mixed extents+bitmaps, some extents may not be trimmed.
- With mixed extents+bitmaps, some bitmaps may not be trimmed (even
none will be trimmed). Even for those trimmed, not all the free space
in the bitmaps will be trimmed.
I rewrite btrfs_trim_block_group() and break it into two functions.
One is to trim extents only, and the other is to trim bitmaps only.
Before patching:
# fstrim -v /mnt/
/mnt/: 1496465408 bytes were trimmed
After patching:
# fstrim -v /mnt/
/mnt/: 2193768448 bytes were trimmed
And this matches the total free space:
# btrfs fi df /mnt
Data: total=3.58GB, used=1.79GB
System, DUP: total=8.00MB, used=4.00KB
System: total=4.00MB, used=0.00
Metadata, DUP: total=205.12MB, used=97.14MB
Metadata: total=8.00MB, used=0.00
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
For btrfs raid, while discarding a range of space, we'll need to know
the start offset and length to discard for each device, and it's done
in btrfs_map_block().
However the calculation is a bit complex for raid0 and raid10, so I
reimplement it based on a fact that:
dev1 dev2 dev3 (raid0)
-----------------------------------
s0 s3 s6 s1 s4 s7 s2 s5
Each device has (total_stripes / nr_dev) stripes, or plus one.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
We pre-allocate a btrfs bio with fixed size, and then may re-allocate
memory if we find stripes are bigger than the fixed size. But this
pre-allocation is not necessary.
Also we don't have to calcuate the stripe number twice.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
If we run into some failure path in io_ctl_prepare_pages(),
io_ctl->pages[] array may have some NULL pointers.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
I got this while running xfstests:
[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600
We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the latter can be obtained from the former (by looking as ->tree_root)
just as cheaply as we currently are doing the other way round.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and don't bother with it after btrfs_fill_super() failure -
->kill_sb() (unlike ->put_super()) will be called even if we
have not got non-NULL ->s_root.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We do not (fortunately) modify ->s_fs_info of superblock on the fly in
btrfs_fill_super(); apparent assignment is a no-op.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It returns either ERR_PTR(-ve) or sb->s_fs_info. The latter can
be found by caller just as well, TYVM, no need to return it. Just
return -ve or 0...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
close_ctree() uses a weird mix of accesses to root->fs_info and
its value at the beginning of function stored in local variable.
Since ->fs_info *never* changes, let's just use the local variable
to avoid confusion.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A new helper: btrfs_alloc_root(fs_info); allocates btrfs_root
and sets ->fs_info. All places allocating the suckers converted
to it. At that point we *never* reassign ->fs_info of btrfs_root;
it's set before anyone sees the address of newly allocated
struct btrfs_root and never assigned anywhere else.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
move assignments to ->fs_info in open_ctree() up, to the place
just after the original allocations. Assignment for tree_root
becomes a no-op - we'd obtained fs_info from tree_root->fs_info
in the first place.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pathname resolution under a global mutex, taken on some paths in ->mount()
is a Bad Idea(tm) - think what happens if said pathname resolution triggers
automount of some btrfs instance and walks into attempt to grab the same
mutex. Deadlock - we are waiting for daemon to finish walking the path,
daemon is waiting for us to release the mutex...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Do *NOT* skip doomed superblocks in btrfs_test_super(); we want
sget() to wait for their shutdown to complete. Since we don't
mutilate ->s_fs_info in ->put_super() anymore (or free what it
used to point to until the superblock is past being findable
by sget()), we can just DTRT there and report a match.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and move free_fs_info() to that, out of ->put_super(). Do NOT
set ->s_fs_info to NULL in the latter; we need it for sget() to
be able to see and wait for fs in the middle of umount if we get a
mount/umount race.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need fs_info and root to live until the moment when the victim
superblock leaves the list, so we need to postpone free_fs_info()
until after ->put_super(). The call is buried in close_ctree(),
though, so we need to lift it into the callers (including
btrfs_put_super()) first.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (53 commits)
Kconfig: acpi: Fix typo in comment.
misc latin1 to utf8 conversions
devres: Fix a typo in devm_kfree comment
btrfs: free-space-cache.c: remove extra semicolon.
fat: Spelling s/obsolate/obsolete/g
SCSI, pmcraid: Fix spelling error in a pmcraid_err() call
tools/power turbostat: update fields in manpage
mac80211: drop spelling fix
types.h: fix comment spelling for 'architectures'
typo fixes: aera -> area, exntension -> extension
devices.txt: Fix typo of 'VMware'.
sis900: Fix enum typo 'sis900_rx_bufer_status'
decompress_bunzip2: remove invalid vi modeline
treewide: Fix comment and string typo 'bufer'
hyper-v: Update MAINTAINERS
treewide: Fix typos in various parts of the kernel, and fix some comments.
clockevents: drop unknown Kconfig symbol GENERIC_CLOCKEVENTS_MIGR
gpio: Kconfig: drop unknown symbol 'CS5535_GPIO'
leds: Kconfig: Fix typo 'D2NET_V2'
sound: Kconfig: drop unknown symbol ARCH_CLPS7500
...
Fix up trivial conflicts in arch/powerpc/platforms/40x/Kconfig (some new
kconfig additions, close to removed commented-out old ones)
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
PM / Hibernate: Implement compat_ioctl for /dev/snapshot
PM / Freezer: fix return value of freezable_schedule_timeout_killable()
PM / shmobile: Allow the A4R domain to be turned off at run time
PM / input / touchscreen: Make st1232 use device PM QoS constraints
PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
PM / shmobile: Remove the stay_on flag from SH7372's PM domains
PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
ARM: S3C64XX: Implement basic power domain support
PM / shmobile: Use common always on power domain governor
...
Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
Parameterize clusters on minimum total size, minimum chunk size and
minimum contiguous size for at least one chunk, without limits on
cluster, window or gap sizes. Don't tolerate any fragmentation for
SSD_SPREAD; accept it for metadata, but try to keep data dense.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We store the allocation start and length twice in ins, once right
after the other, but with intervening calls that may prevent the
duplicate from being optimized out by the compiler. Remove one of the
assignments.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Since the clustered allocation may be taking extents from a different
block group, there's no point in spin-locking and testing the current
block group free space before attempting to allocate space from a
cluster, even more so when we might refrain from even trying the
cluster in the current block group because, after the cluster was set
up, not enough free space remained. Furthermore, cluster creation
attempts fail fast when the block group doesn't have enough free
space, so the test was completely superfluous.
I've move the free space test past the cluster allocation attempt,
where it is more useful, and arranged for a cluster in the current
block group to be released before trying an unclustered allocation,
when we reach the LOOP_NO_EMPTY_SIZE stage, so that the free space in
the cluster stands a chance of being combined with additional free
space in the block group so as to succeed in the allocation attempt.
Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The chunk allocation code has tried to keep a pretty tight lid on creating new
metadata chunks. This is partially because in the past the reservation
code didn't give us an accurate idea of how much space was being used.
The new code is much more accurate, so we're able to get rid of some of these
checks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs tries to batch extent allocation tree changes to improve performance
and reduce metadata trashing. But it doesn't allocate new metadata chunks
while it is doing allocations for the extent allocation tree.
This commit changes the delayed refence code to do chunk allocations if we're
getting low on room. It prevents crashes and improves performance.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There's code in btrfs_get_extent that should never be used. This patch turns
a WARN_ON(1) into a BUG(), hoping we can remove the transaction code from
btrfs_get_extent soon.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
The old backref iteration code could only safely be used on commit roots.
Besides this limitation, it had bugs in finding the roots for these
references. This commit replaces large parts of it by btrfs_find_all_roots()
which a) really finds all roots and the correct roots, b) works correctly
under heavy file system load, c) considers delayed refs.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
This function gets a byte number (a data extent), collects all the leafs
pointing to it and walks up the trees to find all fs roots pointing to those
leafs. It also returns the list of all leafs pointing to that extent.
It does proper locking for the involved trees, can be used on busy file
systems and honors delayed refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Now that we may be holding back delayed refs for a limited period, we
might end up having no runnable delayed refs. Without this commit, we'd
do busy waiting in that thread until another (runnable) ref arives.
Instead, we're detecting this situation and use a waitqueue, such that
we only try to run more refs after
a) another runnable ref was added or
b) delayed refs are no longer held back
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
When processing a delayed ref, first check if there are still old refs in
the process of being added. If so, put this ref back to the tree. To avoid
looping on this ref, choose a newer one in the next loop.
btrfs_find_ref_cluster has to take care of that.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Sequence numbers are needed to reconstruct the backrefs of a given extent to
a certain point in time. The total set of backrefs consist of the set of
backrefs recorded on disk plus the enqueued delayed refs for it that existed
at that moment.
This patch also adds a list that records all delayed refs which are
currently in the process of being added.
When walking all refs of an extent in btrfs_find_all_roots(), we freeze the
current state of delayed refs, honor anythinh up to this point and prevent
processing newer delayed refs to assert consistency.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
This patch adds the possibilty to read-lock an extent even if it is already
write-locked from the same thread. btrfs_find_all_roots() needs this
capability.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
it's not needed anymore; we used to, back when we had to do
mount_subtree() by hand, complete with put_mnt_ns() in it.
No more... Apparmor didn't need it since the __d_path() fix.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pm-sleep: (51 commits)
PM: Drop generic_subsys_pm_ops
PM / Sleep: Remove forward-only callbacks from AMBA bus type
PM / Sleep: Remove forward-only callbacks from platform bus type
PM: Run the driver callback directly if the subsystem one is not there
PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
PM / Sleep: Merge internal functions in generic_ops.c
PM / Sleep: Simplify generic system suspend callbacks
PM / Hibernate: Remove deprecated hibernation snapshot ioctls
PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
PM / Sleep: Recommend [un]lock_system_sleep() over using pm_mutex directly
PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()
PM / Sleep: Make [un]lock_system_sleep() generic
PM / Sleep: Use the freezer_count() functions in [un]lock_system_sleep() APIs
PM / Freezer: Remove the "userspace only" constraint from freezer[_do_not]_count()
PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c with 'else'
Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer
PM / Sleep: Unify diagnostic messages from device suspend/resume
ACPI / PM: Do not save/restore NVS on Asus K54C/K54HR
PM / Hibernate: Remove deprecated hibernation test modes
PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path
...
Conflicts:
kernel/kmod.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: call d_instantiate after all ops are setup
Btrfs: fix worker lock misuse in find_worker
This closes races where btrfs is calling d_instantiate too soon during
inode creation. All of the callers of btrfs_add_nondir are updated to
instantiate after the inode is fully setup in memory.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Dan Carpenter noticed that we were doing a double unlock on the worker
lock, and sometimes picking a worker thread without the lock held.
This fixes both errors.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
For consistent backref walking and (later) qgroup calculation the
information to which root a delayed ref belongs is useful even for shared
refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Add a for_cow parameter to add_delayed_*_ref and pass the appropriate value
from every call site. The for_cow parameter will later on be used to
determine if a ref will change anything with respect to qgroups.
Delayed refs coming from relocation are always counted as for_cow, as they
don't change subvol quota.
Also pass in the fs_info for later use.
btrfs_find_all_roots() will use this as an optimization, as changes that are
for_cow will not change anything with respect to which root points to a
certain leaf. Thus, we don't need to add the current sequence number to
those delayed refs.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
btrfs_next_item() makes the btrfs path point to the next item, crossing leaf
boundaries if needed.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
ulist is a generic data structures to hold a collection of unique u64
values. The only operations it supports is adding to the list and
enumerating it.
It is possible to store an auxiliary value along with the key. The
implementation is preliminary and can probably be sped up significantly.
It is used by btrfs_find_all_roots() quota to translate recursions into
iterative loops.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
* master: (848 commits)
SELinux: Fix RCU deref check warning in sel_netport_insert()
binary_sysctl(): fix memory leak
mm/vmalloc.c: remove static declaration of va from __get_vm_area_node
ipmi_watchdog: restore settings when BMC reset
oom: fix integer overflow of points in oom_badness
memcg: keep root group unchanged if creation fails
nilfs2: potential integer overflow in nilfs_ioctl_clean_segments()
nilfs2: unbreak compat ioctl
cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemask
evm: prevent racing during tfm allocation
evm: key must be set once during initialization
mmc: vub300: fix type of firmware_rom_wait_states module parameter
Revert "mmc: enable runtime PM by default"
mmc: sdhci: remove "state" argument from sdhci_suspend_host
x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT
IB/qib: Correct sense on freectxts increment and decrement
RDMA/cma: Verify private data length
cgroups: fix a css_set not found bug in cgroup_attach_proc
oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
Revert "xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel"
...
Conflicts:
kernel/cgroup_freezer.c
This is the last part of the patch series. It modifies the btrfs
code to use the integrity check module if configured to do so
with the define BTRFS_FS_CHECK_INTEGRITY. If this define is not set,
the only effective change is that code is added that handles the
mount option to activate the integrity check. If the mount option is
set and the define BTRFS_FS_CHECK_INTEGRITY is not set, that code
complains in the log and the mount fails with EINVAL.
Add the mount option to activate the usage of the integrity check
code.
Add invocation of btrfs integrity check code init and cleanup
function on mount and umount, respectively.
Add hook to call btrfs integrity check code version of
submit_bh/submit_bio.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
If the btrfs integrity check is enabled, the files required to
implement the checks are included in the build.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
The two files added in this patch contain all the code that is
required to implement the integrity checks.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
When doing 1KB sequential writes to the same page,
balance_dirty_pages_ratelimited_nr() should be called once instead of 4
times, the latter makes the dirtier tasks be throttled much too heavy.
Fix it with proper de-accounting on clear_page_dirty_for_io().
CC: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: unplug every once and a while
Btrfs: deal with NULL srv_rsv in the delalloc inode reservation code
Btrfs: only set cache_generation if we setup the block group
Btrfs: don't panic if orphan item already exists
Btrfs: fix leaked space in truncate
Btrfs: fix how we do delalloc reservations and how we free reservations on error
Btrfs: deal with enospc from dirtying inodes properly
Btrfs: fix num_workers_starting bug and other bugs in async thread
BTRFS: Establish i_ops before calling d_instantiate
Btrfs: add a cond_resched() into the worker loop
Btrfs: fix ctime update of on-disk inode
btrfs: keep orphans for subvolume deletion
Btrfs: fix inaccurate available space on raid0 profile
Btrfs: fix wrong disk space information of the files
Btrfs: fix wrong i_size when truncating a file to a larger size
Btrfs: fix btrfs_end_bio to deal with write errors to a single mirror
* 'for-linus-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: lower the dirty balance poll interval
Tests show that the original large intervals can easily make the dirty
limit exceeded on 100 concurrent dd's. So adapt to as large as the
next check point selected by the dirty throttling algorithm.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The btrfs io submission threads can build up massive plug lists. This
keeps things more reasonable so we don't hand over huge dumps of IO at
once.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A user reported a problem booting into a new kernel with the old format inodes.
He was panicing in cow_file_range while writing out the inode cache. This is
because if the block group is not cached we'll just skip writing out the cache,
however if it gets dirtied again in the same transaction and it finished caching
we'd go ahead and write it out, but since we set cache_generation to the transid
we think we've already truncated it and will just carry on, running into
cow_file_range and blowing up. We need to make sure we only set
cache_generation if we've done the truncate. The user tested this patch and
verified that the panic no longer occured. Thanks,
Reported-and-Tested-by: Klaus Bitto <klaus.bitto@gmail.com>
Signed-off-by: Josef Bacik <josef@redhat.com>
I've been hitting this BUG_ON() in btrfs_orphan_add when running xfstest 269 in
a loop. This is because we will add an orphan item, do the truncate, the
truncate will fail for whatever reason (*cough*ENOSPC*cough*) and then we're
left with an orphan item still in the fs. Then we come back later to do another
truncate and it blows up because we already have an orphan item. This is ok so
just fix the BUG_ON() to only BUG() if ret is not EEXIST. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
We were occasionaly leaking space when running xfstest 269. This is because if
we failed to start the transaction in the truncate loop we'd just goto out, but
we need to break so that the inode is removed from the orphan list and the space
is properly freed. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Running xfstests 269 with some tracing my scripts kept spitting out errors about
releasing bytes that we didn't actually have reserved. This took me down a huge
rabbit hole and it turns out the way we deal with reserved_extents is wrong,
we need to only be setting it if the reservation succeeds, otherwise the free()
method will come in and unreserve space that isn't actually reserved yet, which
can lead to other warnings and such. The math was all working out right in the
end, but it caused all sorts of other issues in addition to making my scripts
yell and scream and generally make it impossible for me to track down the
original issue I was looking for. The other problem is with our error handling
in the reservation code. There are two cases that we need to deal with
1) We raced with free. In this case free won't free anything because csum_bytes
is modified before we dro the lock in our reservation path, so free rightly
doesn't release any space because the reservation code may be depending on that
reservation. However if we fail, we need the reservation side to do the free at
that point since that space is no longer in use. So as it stands the code was
doing this fine and it worked out, except in case #2
2) We don't race with free. Nobody comes in and changes anything, and our
reservation fails. In this case we didn't reserve anything anyway and we just
need to clean up csum_bytes but not free anything. So we keep track of
csum_bytes before we drop the lock and if it hasn't changed we know we can just
decrement csum_bytes and carry on.
Because of the case where we can race with free()'s since we have to drop our
spin_lock to do the reservation, I'm going to serialize all reservations with
the i_mutex. We already get this for free in the heavy use paths, truncate and
file write all hold the i_mutex, just needed to add it to page_mkwrite and
various ioctl/balance things. With this patch my space leak scripts no longer
scream bloody murder. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
