Filipe Manana [Wed, 2 Mar 2016 15:49:38 +0000 (15:49 +0000)]
Btrfs: fix loading of orphan roots leading to BUG_ON
When looking for orphan roots during mount we can end up hitting a
BUG_ON() (at root-item.c:btrfs_find_orphan_roots()) if a log tree is
replayed and qgroups are enabled. This is because after a log tree is
replayed, a transaction commit is made, which triggers qgroup extent
accounting which in turn does backref walking which ends up reading and
inserting all roots in the radix tree fs_info->fs_root_radix, including
orphan roots (deleted snapshots). So after the log tree is replayed, when
finding orphan roots we hit the BUG_ON with the following trace:
So fix this by not treating the error -EEXIST, returned when attempting
to insert a root already inserted by the backref walking code, as an error.
The following test case for xfstests reproduces the bug:
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
_cleanup_flakey
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/dmflakey
# real QA test starts here
_supported_fs btrfs
_supported_os Linux
_require_scratch
_require_dm_target flakey
_require_metadata_journaling $SCRATCH_DEV
# Create 2 directories with one file in one of them.
# We use these just to trigger a transaction commit later, moving the file from
# directory a to directory b and doing an fsync against directory a.
mkdir $SCRATCH_MNT/a
mkdir $SCRATCH_MNT/b
touch $SCRATCH_MNT/a/f
sync
# Create a snapshot and delete it. This doesn't really delete the snapshot
# immediately, just makes it inaccessible and invisible to user space, the
# snapshot is deleted later by a dedicated kernel thread (cleaner kthread)
# which is woke up at the next transaction commit.
# A root orphan item is inserted into the tree of tree roots, so that if a
# power failure happens before the dedicated kernel thread does the snapshot
# deletion, the next time the filesystem is mounted it resumes the snapshot
# deletion.
_run_btrfs_util_prog subvolume snapshot $SCRATCH_MNT $SCRATCH_MNT/snap
_run_btrfs_util_prog subvolume delete $SCRATCH_MNT/snap
# Now overwrite half of the extents we wrote before. Because we made a snapshpot
# before, which isn't really deleted yet (since no transaction commit happened
# after we did the snapshot delete request), the non overwritten extents get
# referenced twice, once by the default subvolume and once by the snapshot.
$XFS_IO_PROG -c "pwrite -S 0xbb 4K 8K" $SCRATCH_MNT/foobar | _filter_xfs_io
# Now move file f from directory a to directory b and fsync directory a.
# The fsync on the directory a triggers a transaction commit (because a file
# was moved from it to another directory) and the file fsync leaves a log tree
# with file extent items to replay.
mv $SCRATCH_MNT/a/f $SCRATCH_MNT/a/b
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar
echo "File digest before power failure:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch
# Now simulate a power failure and mount the filesystem to replay the log tree.
# After the log tree was replayed, we used to hit a BUG_ON() when processing
# the root orphan item for the deleted snapshot. This is because when processing
# an orphan root the code expected to be the first code inserting the root into
# the fs_info->fs_root_radix radix tree, while in reallity it was the second
# caller attempting to do it - the first caller was the transaction commit that
# took place after replaying the log tree, when updating the qgroup counters.
_flakey_drop_and_remount
echo "File digest before after failure:"
# Must match what he got before the power failure.
md5sum $SCRATCH_MNT/foobar | _filter_scratch
_unmount_flakey
status=0
exit
Fixes: 2d9e97761087 ("Btrfs: use btrfs_get_fs_root in resolve_indirect_ref") Cc: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
Filipe Manana [Mon, 15 Feb 2016 16:20:26 +0000 (16:20 +0000)]
Btrfs: fix direct IO requests not reporting IO error to user space
If a bio for a direct IO request fails, we were not setting the error in
the parent bio (the main DIO bio), making us not return the error to
user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO()
return the number of bytes issued for IO and not the error a bio created
and submitted by btrfs_submit_direct() got from the block layer.
This essentially happens because when we call:
dio_end_io(dio_bio, bio->bi_error);
It does not set dio_bio->bi_error to the value of the second argument.
So just add this missing assignment in endio callbacks, just as we do in
the error path at btrfs_submit_direct() when we fail to clone the dio bio
or allocate its private object. This follows the convention of what is
done with other similar APIs such as bio_endio() where the caller is
responsible for setting the bi_error field in the bio it passes as an
argument to bio_endio().
This was detected by the new generic test cases in xfstests: 271, 272,
276 and 278. Which essentially setup a dm error target, then load the
error table, do a direct IO write and unload the error table. They
expect the write to fail with -EIO, which was not getting reported
when testing against btrfs.
Cc: stable@vger.kernel.org # 4.3+ Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Filipe Manana <fdmanana@suse.com>
David Sterba [Fri, 13 Nov 2015 12:44:28 +0000 (13:44 +0100)]
btrfs: properly set the termination value of ctx->pos in readdir
The value of ctx->pos in the last readdir call is supposed to be set to
INT_MAX due to 32bit compatibility, unless 'pos' is intentially set to a
larger value, then it's LLONG_MAX.
There's a report from PaX SIZE_OVERFLOW plugin that "ctx->pos++"
overflows (https://forums.grsecurity.net/viewtopic.php?f=1&t=4284), on a
64bit arch, where the value is 0x7fffffffffffffff ie. LLONG_MAX before
the increment.
We can get to that situation like that:
* emit all regular readdir entries
* still in the same call to readdir, bump the last pos to INT_MAX
* next call to readdir will not emit any entries, but will reach the
bump code again, finds pos to be INT_MAX and sets it to LLONG_MAX
Normally this is not a problem, but if we call readdir again, we'll find
'pos' set to LLONG_MAX and the unconditional increment will overflow.
The report from Victor at
(http://thread.gmane.org/gmane.comp.file-systems.btrfs/49500) with debugging
print shows that pattern:
The jump from 7fffffff to 7fffffffffffffff happens when new dir entries
are not yet synced and are processed from the delayed list. Then the code
could go to the bump section again even though it might not emit any new
dir entries from the delayed list.
The fix avoids entering the "bump" section again once we've finished
emitting the entries, both for synced and delayed entries.
References: https://forums.grsecurity.net/viewtopic.php?f=1&t=4284 Reported-by: Victor <services@swwu.com> CC: stable@vger.kernel.org Signed-off-by: David Sterba <dsterba@suse.com> Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Chris Mason <clm@fb.com>
This happens because in the code path executed by the inode_paths ioctl we
end up nesting two calls to read lock a leaf's rwlock when after the first
call to read_lock() and before the second call to read_lock(), another
task (running the delayed items as part of a transaction commit) has
already called write_lock() against the leaf's rwlock. This situation is
illustrated by the following diagram:
read_lock(&eb->lock);
--> makes this task hang
forever (and task B too
of course)
So fix this by avoiding doing the nested read lock, which is easily
avoidable. This issue does not happen if task B calls write_lock() after
task A does the second call to read_lock(), however there does not seem
to exist anything in the documentation that mentions what is the expected
behaviour for recursive locking of rwlocks (leaving the idea that doing
so is not a good usage of rwlocks).
Also, as a side effect necessary for this fix, make sure we do not
needlessly read lock extent buffers when the input path has skip_locking
set (used when called from send).
Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>
Filipe Manana [Wed, 27 Jan 2016 18:37:47 +0000 (18:37 +0000)]
Btrfs: fix page reading in extent_same ioctl leading to csum errors
In the extent_same ioctl, we were grabbing the pages (locked) and
attempting to read them without bothering about any concurrent IO
against them. That is, we were not checking for any ongoing ordered
extents nor waiting for them to complete, which leads to a race where
the extent_same() code gets a checksum verification error when it
reads the pages, producing a message like the following in dmesg
and making the operation fail to user space with -ENOMEM:
Fix this by using btrfs_readpage() for reading the pages instead of
extent_read_full_page_nolock(), which waits for any concurrent ordered
extents to complete and locks the io range. Also do better error handling
and don't treat all failures as -ENOMEM, as that's clearly misleasing,
becoming identical to the checks and operation of prepare_uptodate_page().
The use of extent_read_full_page_nolock() was required before
commit f441460202cb ("btrfs: fix deadlock with extent-same and readpage"),
as we had the range locked in an inode's io tree before attempting to
read the pages.
Fixes: f441460202cb ("btrfs: fix deadlock with extent-same and readpage") Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
Filipe Manana [Wed, 27 Jan 2016 10:20:58 +0000 (10:20 +0000)]
Btrfs: fix invalid page accesses in extent_same (dedup) ioctl
In the extent_same ioctl we are getting the pages for the source and
target ranges and unlocking them immediately after, which is incorrect
because later we attempt to map them (with kmap_atomic) and access their
contents at btrfs_cmp_data(). When we do such access the pages might have
been relocated or removed from memory, which leads to an invalid memory
access. This issue is detected on a kernel with CONFIG_DEBUG_PAGEALLOC=y
which produces a trace like the following:
(gdb) list *(btrfs_ioctl+0x24cb)
0x5e0e1 is in btrfs_ioctl (fs/btrfs/ioctl.c:2972).
2967 dst_addr = kmap_atomic(dst_page);
2968
2969 flush_dcache_page(src_page);
2970 flush_dcache_page(dst_page);
2971
2972 if (memcmp(addr, dst_addr, cmp_len))
2973 ret = BTRFS_SAME_DATA_DIFFERS;
2974
2975 kunmap_atomic(addr);
2976 kunmap_atomic(dst_addr);
So fix this by making sure we keep the pages locked and respect the same
locking order as everywhere else: get and lock the pages first and then
lock the range in the inode's io tree (like for example at
__btrfs_buffered_write() and extent_readpages()). If an ordered extent
is found after locking the range in the io tree, unlock the range,
unlock the pages, wait for the ordered extent to complete and repeat the
entire locking process until no overlapping ordered extents are found.
Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
This ends up doing sysfs operations from deep in balance (where we
should be GFP_NOFS) and under heavy balance load, we're making races
against sysfs internals.
David Sterba [Mon, 25 Jan 2016 10:02:06 +0000 (11:02 +0100)]
Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"
This reverts commit 696249132158014d594896df3a81390616069c5c. The
cleaner thread can block freezing when there's a snapshot cleaning in
progress and the other threads get suspended first. From the logs
provided by Martin we're waiting for reading extent pages:
Qu Wenruo [Fri, 22 Jan 2016 01:28:38 +0000 (09:28 +0800)]
btrfs: async-thread: Fix a use-after-free error for trace
Parameter of trace_btrfs_work_queued() can be freed in its workqueue.
So no one use use that pointer after queue_work().
Fix the user-after-free bug by move the trace line before queue_work().
Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
Filipe Manana [Thu, 21 Jan 2016 10:17:54 +0000 (10:17 +0000)]
Btrfs: fix race between fsync and lockless direct IO writes
An fsync, using the fast path, can race with a concurrent lockless direct
IO write and end up logging a file extent item that points to an extent
that wasn't written to yet. This is because the fast fsync path collects
ordered extents into a local list and then collects all the new extent
maps to log file extent items based on them, while the direct IO write
path creates the new extent map before it creates the corresponding
ordered extent (and submitting the respective bio(s)).
So fix this by making the direct IO write path create ordered extents
before the extent maps and make the fast fsync path collect any new
ordered extents after it collects the extent maps.
Note that making the fsync handler call inode_dio_wait() (after acquiring
the inode's i_mutex) would not work and lead to a deadlock when doing
AIO, as through AIO we end up in a path where the fsync handler is called
(through dio_aio_complete_work() -> dio_complete() -> vfs_fsync_range())
before the inode's dio counter is decremented (inode_dio_wait() waits
for this counter to have a value of zero).
Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
David Sterba [Fri, 22 Jan 2016 16:16:18 +0000 (17:16 +0100)]
btrfs: tweak free space tree bitmap allocation
The requested bitmap size varies, observed numbers were < 4K up to 16K.
Using vmalloc unconditionally would be too heavy, we'll try contiguous
allocations first and fall back to vmalloc if there's no contig memory.
David Sterba [Thu, 21 Jan 2016 17:54:41 +0000 (18:54 +0100)]
btrfs: synchronize incompat feature bits with sysfs files
The files under /sys/fs/UUID/features get out of sync with the actual
incompat bits set for the filesystem if they change after mount (eg. the
LZO compression).
Synchronize the feature bits with the sysfs files representing them
right after we set/clear them.
David Sterba [Thu, 21 Jan 2016 17:50:40 +0000 (18:50 +0100)]
btrfs: sysfs: introduce helper for syncing bits with sysfs files
The files under /sys/fs/UUID/features get out of sync with the actual
incompat bits set for the filesystem if they change after mount. We're
going to sync them and need a helper to do that.
David Sterba [Thu, 21 Jan 2016 17:36:46 +0000 (18:36 +0100)]
btrfs: sysfs: add free-space-tree bit attribute
The incompat bit representing the newly added free space tree feature is
missing. Right now it will be listed only among features supported by
the module, not per-fs.
Zhao Lei [Tue, 12 Jan 2016 09:52:13 +0000 (17:52 +0800)]
btrfs: raid56: Use raid_write_end_io for scrub
No need to create additional end_io function for scrub, it increased
code size and introduced some un-unified lines, as:
raid_write_parity_end_io():
int err = bio->bi_error;
if (bio->bi_error)
raid_write_end_io():
int err = bio->bi_error;
if (err)
This patch combines them.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
Zhao Lei [Tue, 3 Mar 2015 12:38:46 +0000 (20:38 +0800)]
btrfs: Use unified stripe_page's index calculation
We are using different index calculation method for stripe_page in
current code:
1: (rbio->stripe_len / PAGE_CACHE_SIZE) * stripe_index + page_index
2: DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE) * stripe_index + page_index
3: DIV_ROUND_UP(rbio->stripe_len * stripe_index, PAGE_CACHE_SIZE) + page_index
...
They can get same result when stripe_len align to PAGE_CACHE_SIZE,
this is why current code can work, intruduce and use a common function
for calculation is a better choose.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
Zhao Lei [Mon, 8 Dec 2014 11:55:57 +0000 (19:55 +0800)]
btrfs: Fix calculation of rbio->dbitmap's size calculation
Current code is trying to calculate rbio->dbitmap's size to make it
align to sizeof(long), but implement haven't achived this object,
it is align to sizeof(char) instead.
This patch fixed above calculation, and use sizeof(long) instead of
fixed "8" to increate compatibility.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
Zhao Lei [Tue, 1 Dec 2015 10:39:40 +0000 (18:39 +0800)]
btrfs: Fix no_space in write and rm loop
I see no_space in v4.4-rc1 again in xfstests generic/102.
It happened randomly in some node only.
(one of 4 phy-node, and a kvm with non-virtio block driver)
By bisect, we can found the first-bad is:
commit bdced438acd8 ("block: setup bi_phys_segments after splitting")'
But above patch only triggered the bug by making bio operation
faster(or slower).
Main reason is in our space_allocating code, we need to commit
page writeback before wait it complish, this patch fixed above
bug.
BTW, there is another reason for generic/102 fail, caused by
disable default mixed-blockgroup, I'll fix it in xfstests.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
Qu Wenruo [Tue, 15 Dec 2015 01:14:37 +0000 (09:14 +0800)]
btrfs: Enhance chunk validation check
Enhance chunk validation:
1) Num_stripes
We already have such check but it's only in super block sys chunk
array.
Now check all on-disk chunks.
2) Chunk logical
It should be aligned to sector size.
This behavior should be *DOUBLE CHECKED* for 64K sector size like
PPC64 or AArch64.
Maybe we can found some hidden bugs.
3) Chunk length
Same as chunk logical, should be aligned to sector size.
4) Stripe length
It should be power of 2.
5) Chunk type
Any bit out of TYPE_MAS | PROFILE_MASK is invalid.
With all these much restrict rules, several fuzzed image reported in
mail list should no longer cause kernel panic.
Qu Wenruo [Tue, 15 Dec 2015 01:14:36 +0000 (09:14 +0800)]
btrfs: Enhance super validation check
Enhance btrfs_check_super_valid() function by the following points:
1) Restrict sector/node size check
Not the old max/min valid check, but also check if it's a power of 2.
So some bogus number like 12K node size won't pass now.
2) Super flag check
For now, there is still some inconsistency between kernel and
btrfs-progs super flags.
And considering btrfs-progs may add new flags for super block, this
check will only output warning.
3) Better root alignment check
Now root bytenr is checked against sector size.
4) Move some check into btrfs_check_super_valid().
Like node size vs leaf size check, and PAGESIZE vs sectorsize check.
And magic number check.
Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
This happens because we can recursively acquire the semaphore
fs_info->delayed_iput_sem when attempting to allocate space to satisfy
a file write request as shown in the first trace above - when committing
a transaction we acquire (down_read) the semaphore before running the
delayed iputs, and when running a delayed iput() we can end up calling
an inode's eviction handler, which in turn commits another transaction
and attempts to acquire (down_read) again the semaphore to run more
delayed iput operations.
This results in a deadlock because if a task acquires multiple times a
semaphore it should invoke down_read_nested() with a different lockdep
class for each level of recursion.
Fix this by simplifying the implementation and use a mutex instead that
is acquired by the cleaner kthread before it runs the delayed iputs
instead of always acquiring a semaphore before delayed references are
run from anywhere.
Fixes: d7c151717a1e (btrfs: Fix NO_SPACE bug caused by delayed-iput) Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
Filipe Manana [Fri, 15 Jan 2016 10:56:15 +0000 (10:56 +0000)]
Btrfs: fix typo in log message when starting a balance
The recent change titled "Btrfs: Check metadata redundancy on balance"
(already in linux-next) left a typo in a message for users:
metatdata -> metadata.
Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
btrfs: initialize the seq counter in struct btrfs_device
I managed to trigger this:
| INFO: trying to register non-static key.
| the code is fine but needs lockdep annotation.
| turning off the locking correctness validator.
| CPU: 1 PID: 781 Comm: systemd-gpt-aut Not tainted 4.4.0-rt2+ #14
| Hardware name: ARM-Versatile Express
| [<80307cec>] (dump_stack)
| [<80070e98>] (__lock_acquire)
| [<8007184c>] (lock_acquire)
| [<80287800>] (btrfs_ioctl)
| [<8012a8d4>] (do_vfs_ioctl)
| [<8012ac14>] (SyS_ioctl)
so I think that btrfs_device_data_ordered_init() is not invoked behind
a macro somewhere.
Fixes: 7cc8e58d53cd ("Btrfs: fix unprotected device's variants on 32bits machine") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Dan Carpenter [Wed, 13 Jan 2016 12:21:17 +0000 (15:21 +0300)]
Btrfs: clean up an error code in btrfs_init_space_info()
If we return 1 here, then the caller treats it as an error and returns
-EINVAL. It causes a static checker warning to treat positive returns
as an error.
Fixes: 1aba86d67f34 ('Btrfs: fix easily get into ENOSPC in mixed case') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Geliang Tang [Wed, 13 Jan 2016 14:08:01 +0000 (22:08 +0800)]
btrfs: fix iterator with update error in backref.c
Fix the following error:
fs/btrfs/backref.c:565:1-20: iterator with update on line 577
Fixes: a7ca422('btrfs: use list_for_each_entry* in backref.c') Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: David Sterba <dsterba@suse.com>
Tsutomu Itoh [Wed, 6 Jan 2016 08:03:40 +0000 (17:03 +0900)]
Btrfs: fix output of compression message in btrfs_parse_options()
The compression message might not be correctly output.
Fix it.
[[before fix]]
# mount -o compress /dev/sdb3 /test3
[ 996.874264] BTRFS info (device sdb3): disk space caching is enabled
[ 996.874268] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)
# mount -o remount,compress-force /dev/sdb3 /test3
[ 1035.075017] BTRFS info (device sdb3): force zlib compression
[ 1035.075021] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)
# mount -o remount,compress /dev/sdb3 /test3
[ 1053.679092] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)
[[after fix]]
# mount -o compress /dev/sdb3 /test3
[ 401.021753] BTRFS info (device sdb3): use zlib compression
[ 401.021758] BTRFS info (device sdb3): disk space caching is enabled
[ 401.021760] BTRFS: has skinny extents
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)
# mount -o remount,compress-force /dev/sdb3 /test3
[ 439.824624] BTRFS info (device sdb3): force zlib compression
[ 439.824629] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress-force=zlib,space_cache,subvolid=5,subvol=/)
# mount -o remount,compress /dev/sdb3 /test3
[ 459.918430] BTRFS info (device sdb3): use zlib compression
[ 459.918434] BTRFS info (device sdb3): disk space caching is enabled
# mount | grep /test3
/dev/sdb3 on /test3 type btrfs (rw,relatime,compress=zlib,space_cache,subvolid=5,subvol=/)
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
Mount filesystem
Create subvol with ID 257
Unmount filesystem
Mount filesystem
Delete subvol with ID 257
btrfs_drop_snapshot()
Add root corresponding to subvol 257 into
btrfs_transaction->dropped_roots list
Create new subvol (i.e. create_subvol())
257 is returned as the next free objectid
btrfs_read_fs_root_no_name()
Finds the btrfs_root instance corresponding to the old subvol with ID 257
in btrfs_fs_info->fs_roots_radix.
Returns error since btrfs_root_item->refs has the value of 0.
To fix the issue the commit initializes tree root's and subvolume root's
highest_objectid when loading the roots from disk.
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
Jeff Mahoney [Wed, 3 Jun 2015 14:55:48 +0000 (10:55 -0400)]
btrfs: cleanup, stop casting for extent_map->lookup everywhere
Overloading extent_map->bdev to struct map_lookup * might have started out
as a means to an end, but it's a pattern that's used all over the place
now. Let's get rid of the casting and just add a union instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Wed, 6 Jan 2016 22:42:35 +0000 (22:42 +0000)]
Btrfs: fix fitrim discarding device area reserved for boot loader's use
As of the 4.3 kernel release, the fitrim ioctl can now discard any region
of a disk that is not allocated to any chunk/block group, including the
first megabyte which is used for our primary superblock and by the boot
loader (grub for example).
Fix this by not allowing to trim/discard any region in the device starting
with an offset not greater than min(alloc_start_mount_option, 1Mb), just
as it was not possible before 4.3.
A reproducer test case for xfstests follows.
seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"
tmp=/tmp/$$
status=1 # failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15
_cleanup()
{
cd /
rm -f $tmp.*
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
# real QA test starts here
_need_to_be_root
_supported_fs btrfs
_supported_os Linux
_require_scratch
rm -f $seqres.full
_scratch_mkfs >>$seqres.full 2>&1
# Write to the [0, 64Kb[ and [68Kb, 1Mb[ ranges of the device. These ranges are
# reserved for a boot loader to use (GRUB for example) and btrfs should never
# use them - neither for allocating metadata/data nor should trim/discard them.
# The range [64Kb, 68Kb[ is used for the primary superblock of the filesystem.
$XFS_IO_PROG -c "pwrite -S 0xfd 0 64K" $SCRATCH_DEV | _filter_xfs_io
$XFS_IO_PROG -c "pwrite -S 0xfd 68K 956K" $SCRATCH_DEV | _filter_xfs_io
# Now mount the filesystem and perform a fitrim against it.
_scratch_mount
_require_batched_discard $SCRATCH_MNT
$FSTRIM_PROG $SCRATCH_MNT
# Now unmount the filesystem and verify the content of the ranges was not
# modified (no trim/discard happened on them).
_scratch_unmount
echo "Content of the ranges [0, 64Kb] and [68Kb, 1Mb[ after fitrim:"
od -t x1 -N $((64 * 1024)) $SCRATCH_DEV
od -t x1 -j $((68 * 1024)) -N $((956 * 1024)) $SCRATCH_DEV
status=0
exit
Reported-by: Vincent Petry <PVince81@yahoo.fr> Reported-by: Andrei Borzenkov <arvidjaar@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109341 Fixes: 499f377f49f0 (btrfs: iterate over unused chunk space in FITRIM) Cc: stable@vger.kernel.org # 4.3+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
Sam Tygier [Wed, 6 Jan 2016 08:46:12 +0000 (08:46 +0000)]
Btrfs: Check metadata redundancy on balance
When converting a filesystem via balance check that metadata mode
is at least as redundant as the data mode. For example give warning
when:
-dconvert=raid1 -mconvert=single
Signed-off-by: Sam Tygier <samtygier@yahoo.co.uk>
[ minor message reformatting ] Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Sat, 10 Oct 2015 15:59:53 +0000 (17:59 +0200)]
btrfs: statfs: report zero available if metadata are exhausted
There is one ENOSPC case that's very confusing. There's Available
greater than zero but no file operation succeds (besides removing
files). This happens when the metadata are exhausted and there's no
possibility to allocate another chunk.
In this scenario it's normal that there's still some space in the data
chunk and the calculation in df reflects that in the Avail value.
To at least give some clue about the ENOSPC situation, let statfs report
zero value in Avail, even if there's still data space available.
Current:
/dev/sdb1 4.0G 3.3G 719M 83% /mnt/test
New:
/dev/sdb1 4.0G 3.3G 0 100% /mnt/test
We calculate the remaining metadata space minus global reserve. If this
is (supposedly) smaller than zero, there's no space. But this does not
hold in practice, the exhausted state happens where's still some
positive delta. So we apply some guesswork and compare the delta to a 4M
threshold. (Practically observed delta was 2M.)
We probably cannot calculate the exact threshold value because this
depends on the internal reservations requested by various operations, so
some operations that consume a few metadata will succeed even if the
Avail is zero. But this is better than the other way around.
David Sterba [Tue, 10 Nov 2015 17:54:00 +0000 (18:54 +0100)]
btrfs: allocate root item at snapshot ioctl time
The actual snapshot creation is delayed until transaction commit. If we
cannot get enough memory for the root item there, we have to fail the
whole transaction commit which is bad. So we'll allocate the memory at
the ioctl call and pass it along with the pending_snapshot struct. The
potential ENOMEM will be returned to the caller of snapshot ioctl.
David Sterba [Fri, 27 Nov 2015 15:31:45 +0000 (16:31 +0100)]
btrfs: use smaller type for btrfs_path locks
The values of btrfs_path::locks are 0 to 4, fit into a u8. Let's see:
* overall size of btrfs_path drops down from 136 to 112 (-24 bytes),
* better packing in a slab page +6 objects
* the whole structure now fits to 2 cachelines
* slight decrease in code size:
text data bss dec hex filename
938731 43670 23144 1005545 f57e9 fs/btrfs/btrfs.ko.before
938203 43670 23144 1005017 f55d9 fs/btrfs/btrfs.ko.after
(and the generated assembly does not change much)
The main purpose is to decrease the size of the structure without
affecting performance. The byte access is usually well behaving accross
arches, the locks are not accessed frequently and sometimes just
compared to zero.
Note for further size reduction attempts: the slots could be made u16
but this might generate worse code on some arches (non-byte and non-int
access). Also the range of operations on slots is wider compared to
locks and the potential performance drop should be evaluated first.
David Sterba [Fri, 27 Nov 2015 15:31:35 +0000 (16:31 +0100)]
btrfs: cleanup, use enum values for btrfs_path reada
Replace the integers by enums for better readability. The value 2 does
not have any meaning since a717531942f488209dded30f6bc648167bcefa72
"Btrfs: do less aggressive btree readahead" (2009-01-22).
David Sterba [Thu, 19 Nov 2015 10:42:31 +0000 (11:42 +0100)]
btrfs: constify static arrays
There are a few statically initialized arrays that can be made const.
The remaining (like file_system_type, sysfs attributes or prop handlers)
do not allow that due to type mismatch when passed to the APIs or
because the structures are modified through other members.
David Sterba [Thu, 19 Nov 2015 10:42:24 +0000 (11:42 +0100)]
btrfs tests: replace whole ops structure for free space tests
Preparatory work for making btrfs_free_space_op constant. In
test_steal_space_from_bitmap_to_extent, we substitute use_bitmap with
own version thus preventing constification. We can rework it so we
replace the whole structure with the correct function pointers.
Byongho Lee [Mon, 14 Dec 2015 16:42:10 +0000 (01:42 +0900)]
Btrfs: use linux/sizes.h to represent constants
We use many constants to represent size and offset value. And to make
code readable we use '256 * 1024 * 1024' instead of '268435456' to
represent '256MB'. However we can make far more readable with 'SZ_256MB'
which is defined in the 'linux/sizes.h'.
So this patch replaces 'xxx * 1024 * 1024' kind of expression with
single 'SZ_xxxMB' if 'xxx' is a power of 2 then 'xxx * SZ_1M' if 'xxx' is
not a power of 2. And I haven't touched to '4096' & '8192' because it's
more intuitive than 'SZ_4KB' & 'SZ_8KB'.
Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
Alexandru Moise [Sun, 25 Oct 2015 19:35:44 +0000 (19:35 +0000)]
btrfs: pass proper enum type to start_transaction()
Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba [Tue, 8 Dec 2015 13:39:32 +0000 (14:39 +0100)]
btrfs: don't use slab cache for struct btrfs_delalloc_work
Although we prefer to use separate caches for various structs, it seems
better not to do that for struct btrfs_delalloc_work. Objects of this
type are allocated rarely, when transaction commit calls
btrfs_start_delalloc_roots, requesting delayed iputs.
The objects are temporary (with some IO involved) but still allocated
and freed within __start_delalloc_inodes. Memory allocation failure is
handled.
The slab cache is empty most of the time (observed on several systems),
so if we need to allocate a new slab object, the first one has to
allocate a full page. In a potential case of low memory conditions this
might fail with higher probability compared to using the generic slab
caches.
David Sterba [Mon, 30 Nov 2015 16:27:06 +0000 (17:27 +0100)]
btrfs: handle invalid num_stripes in sys_array
We can handle the special case of num_stripes == 0 directly inside
btrfs_read_sys_array. The BUG_ON in btrfs_chunk_item_size is there to
catch other unhandled cases where we fail to validate external data.
A crafted or corrupted image crashes at mount time:
David Sterba [Mon, 30 Nov 2015 15:51:29 +0000 (16:51 +0100)]
btrfs: better packing of btrfs_delayed_extent_op
btrfs_delayed_extent_op can be packed in a better way, it's 40 bytes now
and has 8 unused bytes. Reducing the level type to u8 makes it possible
to squeeze it to the padding byte after key. The bitfields were switched
to bool as there's space to store the full byte without increasing the
whole structure, besides that the generated assembly is smaller.
David Sterba [Thu, 19 Nov 2015 13:15:51 +0000 (14:15 +0100)]
btrfs: put delayed item hook into inode
Inodes for delayed iput allocate a trivial helper structure, let's place
the list hook directly into the inode and save a kmalloc (killing a
__GFP_NOFAIL as a bonus) at the cost of increasing size of btrfs_inode.
The inode can be put into the delayed_iputs list more than once and we
have to keep the count. This means we can't use the list_splice to
process a bunch of inodes because we'd lost track of the count if the
inode is put into the delayed iputs again while it's processed.
test_all()
{
for m_from in single dup; do
for d_from in single dup; do
for m_to in single dup; do
for d_to in single dup; do
do_dup_test "$m_from" "$d_from" "$m_to" "$d_to" || return 1
done
done
done
done
}
test_all
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Josef Bacik [Thu, 22 Oct 2015 19:05:09 +0000 (15:05 -0400)]
Btrfs: igrab inode in writepage
We hit this panic on a few of our boxes this week where we have an
ordered_extent with an NULL inode. We do an igrab() of the inode in writepages,
but weren't doing it in writepage which can be called directly from the VM on
dirty pages. If the inode has been unlinked then we could have I_FREEING set
which means igrab() would return NULL and we get this panic. Fix this by trying
to igrab in btrfs_writepage, and if it returns NULL then just redirty the page
and return AOP_WRITEPAGE_ACTIVATE; so the VM knows it wasn't successful. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
Anand Jain [Wed, 7 Oct 2015 09:23:23 +0000 (17:23 +0800)]
Btrfs: add missing brelse when superblock checksum fails
Looks like oversight, call brelse() when checksum fails. Further down the
code, in the non error path, we do call brelse() and so we don't see
brelse() in the goto error paths.
Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Filipe Manana [Tue, 5 Jan 2016 16:24:05 +0000 (16:24 +0000)]
Btrfs: fix transaction handle leak on failure to create hard link
If we failed to create a hard link we were not always releasing the
the transaction handle we got before, resulting in a memory leak and
preventing any other tasks from being able to commit the current
transaction.
Fix this by always releasing our transaction handle.
Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Filipe Manana [Thu, 31 Dec 2015 18:16:29 +0000 (18:16 +0000)]
Btrfs: fix number of transaction units required to create symlink
We weren't accounting for the insertion of an inline extent item for the
symlink inode nor that we need to update the parent inode item (through
the call to btrfs_add_nondir()). So fix this by including two more
transaction units.
Filipe Manana [Thu, 31 Dec 2015 18:08:24 +0000 (18:08 +0000)]
Btrfs: don't leave dangling dentry if symlink creation failed
When we are creating a symlink we might fail with an error after we
created its inode and added the corresponding directory indexes to its
parent inode. In this case we end up never removing the directory indexes
because the inode eviction handler, called for our symlink inode on the
final iput(), only removes items associated with the symlink inode and
not with the parent inode.
Example:
$ mkfs.btrfs -f /dev/sdi
$ mount /dev/sdi /mnt
$ touch /mnt/foo
$ ln -s /mnt/foo /mnt/bar
ln: failed to create symbolic link ‘bar’: Cannot allocate memory
$ umount /mnt
$ btrfsck /dev/sdi
Checking filesystem on /dev/sdi
UUID: d5acb5ba-31bd-42da-b456-89dca2e716e1
checking extents
checking free space cache
checking fs roots
root 5 inode 258 errors 2001, no inode item, link count wrong
unresolved ref dir 256 index 3 namelen 3 name bar filetype 7 errors 4, no inode ref
found 131073 bytes used err is 1
total csum bytes: 0
total tree bytes: 131072
total fs tree bytes: 32768
total extent tree bytes: 16384
btree space waste bytes: 124305
file data blocks allocated: 262144
referenced 262144
btrfs-progs v4.2.3
So fix this by adding the directory index entries as the very last
step of symlink creation.
Filipe Manana [Thu, 31 Dec 2015 18:07:59 +0000 (18:07 +0000)]
Btrfs: send, don't BUG_ON() when an empty symlink is found
When a symlink is successfully created it always has an inline extent
containing the source path. However if an error happens when creating
the symlink, we can leave in the subvolume's tree a symlink inode without
any such inline extent item - this happens if after btrfs_symlink() calls
btrfs_end_transaction() and before it calls the inode eviction handler
(through the final iput() call), the transaction gets committed and a
crash happens before the eviction handler gets called, or if a snapshot
of the subvolume is made before the eviction handler gets called. Sadly
we can't just avoid this by making btrfs_symlink() call
btrfs_end_transaction() after it calls the eviction handler, because the
later can commit the current transaction before it removes any items from
the subvolume tree (if it encounters ENOSPC errors while reserving space
for removing all the items).
So make send fail more gracefully, with an -EIO error, and print a
message to dmesg/syslog informing that there's an empty symlink inode,
so that the user can delete the empty symlink or do something else
about it.
Reported-by: Stephen R. van den Berg <srb@cuci.nl> Signed-off-by: Filipe Manana <fdmanana@suse.com>
This is a very rare situation and it happened due to a race between a free
space endio worker and writing the space caches for dirty block groups at
a transaction's commit critical section. The steps leading to this are:
1) A task calls btrfs_commit_transaction() and starts the writeout of the
space caches for all currently dirty block groups (i.e. it calls
btrfs_start_dirty_block_groups());
2) The previous step starts writeback for space caches;
3) When the writeback finishes it queues jobs for free space endio work
queue (fs_info->endio_freespace_worker) that execute
btrfs_finish_ordered_io();
4) The task committing the transaction sets the transaction's state
to TRANS_STATE_COMMIT_DOING and shortly after calls
btrfs_write_dirty_block_groups();
5) A free space endio job joins the transaction, through
btrfs_join_transaction_nolock(), and updates a free space inode item
in the root tree through btrfs_update_inode_fallback();
6) Updating the free space inode item resulted in COWing one or more
nodes/leaves of the root tree, and that resulted in creating a new
metadata block group, which gets added to the transaction's list
of dirty block groups (this is a very rare case);
7) The free space endio job has not released yet its transaction handle
at this point, so the new metadata block group was not yet fully
created (didn't go through btrfs_create_pending_block_groups() yet);
8) The transaction commit task sees the new metadata block group in
the transaction's list of dirty block groups and processes it.
When it attempts to update the block group's block group item in
the extent tree, through write_one_cache_group(), it isn't able
to find it and aborts the transaction with error -ENOENT - this
is because the free space endio job hasn't yet released its
transaction handle (which calls btrfs_create_pending_block_groups())
and therefore the block group item was not yet added to the extent
tree.
Fix this waiting for free space endio jobs if we fail to find a block
group item in the extent tree and then retry once updating the block
group item.
Chris Mason [Wed, 30 Dec 2015 15:52:35 +0000 (07:52 -0800)]
btrfs: don't run delayed references while we are creating the free space tree
This is a short term solution to make sure btrfs_run_delayed_refs()
doesn't change the extent tree while we are scanning it to create the
free space tree.
Longer term we need to synchronize scanning the block groups one by one,
similar to what happens during a balance.
Filipe Manana [Fri, 18 Dec 2015 03:02:48 +0000 (03:02 +0000)]
Btrfs: fix unprotected list operations at btrfs_write_dirty_block_groups
We call btrfs_write_dirty_block_groups() in the critical section of a
transaction's commit, when no other tasks can join the transaction and
add more block groups to the transaction's list of dirty block groups,
so we not taking the dirty block groups spinlock when checking for the
list's emptyness, grabbing its first element or deleting elements from
it.
However there's a special and rare case where we can have a concurrent
task adding elements to this list. We trigger writeback for space
caches before at btrfs_start_dirty_block_groups() and in past iterations
of the loop at btrfs_write_dirty_block_groups(), this means that when
the writeback finishes (which happens asynchronously) it creates a
task for the endio free space work queue that executes
btrfs_finish_ordered_io() - this function is able to join the transaction,
through btrfs_join_transaction_nolock(), and update the free space cache's
inode item in the root tree, which can result in COWing nodes of this tree
and therefore allocation of a new block group can happen, which gets added
to the transaction's list of dirty block groups while the transaction
commit task is operating on it concurrently.
So fix this by taking the dirty block groups spinlock before doing
operations on the dirty block groups list at
btrfs_write_dirty_block_groups().
Linus Torvalds [Sun, 20 Dec 2015 18:01:11 +0000 (10:01 -0800)]
Merge tag 'rtc-4.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC fixes from Alexandre Belloni:
"Late fixes for the RTC subsystem for 4.4:
A fix for a nasty hardware bug in rk808 and an initialization
reordering in da9063 to fix a possible crash"
* tag 'rtc-4.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
rtc: da9063: fix access ordering error during RTC interrupt at system power on
rtc: rk808: Compensate for Rockchip calendar deviation on November 31st
Steve Twiss [Tue, 8 Dec 2015 16:28:39 +0000 (16:28 +0000)]
rtc: da9063: fix access ordering error during RTC interrupt at system power on
This fix alters the ordering of the IRQ and device registrations in the RTC
driver probe function. This change will apply to the RTC driver that supports
both DA9063 and DA9062 PMICs.
A problem could occur with the existing RTC driver if:
A system is started from a cold boot using the PMIC RTC IRQ to initiate a
power on operation. For instance, if an RTC alarm is used to start a
platform from power off.
The existing driver IRQ is requested before the device has been properly
registered.
i.e.
ret = devm_request_threaded_irq()
comes before
rtc->rtc_dev = devm_rtc_device_register();
In this case, the interrupt can be called before the device has been
registered and the handler can be called immediately. The IRQ handler
da9063_alarm_event() contains the function call
which in turn tries to access the unavailable rtc->rtc_dev.
The fix is to reorder the functions inside the RTC probe. The IRQ is
requested after the RTC device resource has been registered so that
get_irq_byname is the last thing to happen.
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Julius Werner [Tue, 15 Dec 2015 23:02:49 +0000 (15:02 -0800)]
rtc: rk808: Compensate for Rockchip calendar deviation on November 31st
In A.D. 1582 Pope Gregory XIII found that the existing Julian calendar
insufficiently represented reality, and changed the rules about
calculating leap years to account for this. Similarly, in A.D. 2013
Rockchip hardware engineers found that the new Gregorian calendar still
contained flaws, and that the month of November should be counted up to
31 days instead. Unfortunately it takes a long time for calendar changes
to gain widespread adoption, and just like more than 300 years went by
before the last Protestant nation implemented Greg's proposal, we will
have to wait a while until all religions and operating system kernels
acknowledge the inherent advantages of the Rockchip system. Until then
we need to translate dates read from (and written to) Rockchip hardware
back to the Gregorian format.
This patch works by defining Jan 1st, 2016 as the arbitrary anchor date
on which Rockchip and Gregorian calendars are in sync. From that we can
translate arbitrary later dates back and forth by counting the number
of November/December transitons since the anchor date to determine the
offset between the calendars. We choose this method (rather than trying
to regularly "correct" the date stored in hardware) since it's the only
way to ensure perfect time-keeping even if the system may be shut down
for an unknown number of years. The drawback is that other software
reading the same hardware (e.g. mainboard firmware) must use the same
translation convention (including the same anchor date) to be able to
read and write correct timestamps from/to the RTC.
Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
projects / karo-tx-linux.git / log