Commit Graph

579 Commits

Author SHA1 Message Date
David Sterba
d7f663fa3f btrfs: prune unused includes
Remove includes if none of the interfaces and exports is used in the
given source file.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:43 +02:00
David Sterba
3ffbd68c48 btrfs: simplify pointer chasing of local fs_info variables
Functions that get btrfs inode can simply reach the fs_info by
dereferencing the root and this looks a bit more straightforward
compared to the btrfs_sb(...) indirection.

If the transaction handle is available and not NULL it's used instead.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:43 +02:00
Goldwyn Rodrigues
e4af400a9c btrfs: Use iocb to derive pos instead of passing a separate parameter
struct kiocb carries the ki_pos, so there is no need to pass it as
a separate function parameter.

generic_file_direct_write() increments ki_pos, so we now assign pos
after the function.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
[ rename to btrfs_buffered_write ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:40 +02:00
Qu Wenruo
e41ca58974 btrfs: Get rid of the confusing btrfs_file_extent_inline_len
We used to call btrfs_file_extent_inline_len() to get the uncompressed
data size of an inlined extent.

However this function is hiding evil, for compressed extent, it has no
choice but to directly read out ram_bytes from btrfs_file_extent_item.
While for uncompressed extent, it uses item size to calculate the real
data size, and ignoring ram_bytes completely.

In fact, for corrupted ram_bytes, due to above behavior kernel
btrfs_print_leaf() can't even print correct ram_bytes to expose the bug.

Since we have the tree-checker to verify all EXTENT_DATA, such mismatch
can be detected pretty easily, thus we can trust ram_bytes without the
evil btrfs_file_extent_inline_len().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:38 +02:00
David Sterba
ca5788aba3 btrfs: remove remaing full_sync logic from btrfs_sync_file
The logic to check if the inode is already in the log can now be
simplified since we always wait for the ordered extents to complete
before deciding whether the inode needs to be logged. The big comment
about it can go away too.

CC: Filipe Manana <fdmanana@suse.com>
Suggested-by: Filipe Manana <fdmanana@suse.com>
[ code and changelog copied from mail discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:31 +02:00
Josef Bacik
b5e6c3e170 btrfs: always wait on ordered extents at fsync time
There's a priority inversion that exists currently with btrfs fsync.  In
some cases we will collect outstanding ordered extents onto a list and
only wait on them at the very last second.  However this "very last
second" falls inside of a transaction handle, so if we are in a lower
priority cgroup we can end up holding the transaction open for longer
than needed, so if a high priority cgroup is also trying to fsync()
it'll see latency.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06 13:12:30 +02:00
Deepa Dinamani
95582b0083 vfs: change inode times to use struct timespec64
struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>
2018-06-05 16:57:31 -07:00
Qu Wenruo
336a8bb8e3 btrfs: Fix wrong btrfs_delalloc_release_extents parameter
Commit 43b18595d6 ("btrfs: qgroup: Use separate meta reservation type
for delalloc") merged into mainline is not the latest version submitted
to mail list in Dec 2017.

It has a fatal wrong @qgroup_free parameter, which results increasing
qgroup metadata pertrans reserved space, and causing a lot of early EDQUOT.

Fix it by applying the correct diff on top of current branch.

Fixes: 43b18595d6 ("btrfs: qgroup: Use separate meta reservation type for delalloc")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-18 16:46:57 +02:00
David Sterba
c1d7c514f7 btrfs: replace GPL boilerplate by SPDX -- sources
Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-12 16:29:51 +02:00
Qu Wenruo
43b18595d6 btrfs: qgroup: Use separate meta reservation type for delalloc
Before this patch, btrfs qgroup is mixing per-transcation meta rsv with
preallocated meta rsv, making it quite easy to underflow qgroup meta
reservation.

Since we have the new qgroup meta rsv types, apply it to delalloc
reservation.

Now for delalloc, most of its reserved space will use META_PREALLOC qgroup
rsv type.

And for callers reducing outstanding extent like btrfs_finish_ordered_io(),
they will convert corresponding META_PREALLOC reservation to
META_PERTRANS.

This is mainly due to the fact that current qgroup numbers will only be
updated in btrfs_commit_transaction(), that's to say if we don't keep
such placeholder reservation, we can exceed qgroup limitation.

And for callers freeing outstanding extent in error handler, we will
just free META_PREALLOC bytes.

This behavior makes callers of btrfs_qgroup_release_meta() or
btrfs_qgroup_convert_meta() to be aware of which type they are.
So in this patch, btrfs_delalloc_release_metadata() and its callers get
an extra parameter to info qgroup to do correct meta convert/release.

The good news is, even we use the wrong type (convert or free), it won't
cause obvious bug, as prealloc type is always in good shape, and the
type only affects how per-trans meta is increased or not.

So the worst case will be at most metadata limitation can be sometimes
exceeded (no convert at all) or metadata limitation is reached too soon
(no free at all).

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31 01:41:14 +02:00
Nikolay Borisov
7a5a07a810 btrfs: Remove userspace transaction ioctls
Commit 3558d4f88e ("btrfs: Deprecate userspace transaction ioctls")
marked the beginning of the end of userspace transaction. This commit
finishes the job! There are no known users and ceph does not use the
ioctl anymore.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Sage Weil <sage@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31 01:26:51 +02:00
David Sterba
051c98eb11 btrfs: open code trivial helper btrfs_page_exists_in_range
The called function name is self explanatory.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31 01:26:50 +02:00
Nikolay Borisov
e5b84f7a25 btrfs: Remove root argument from btrfs_log_dentry_safe
Now that nothing uses the root arg of btrfs_log_dentry_safe it can be
safely removed. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:42 +02:00
David Sterba
e67c718b5b btrfs: add more __cold annotations
The __cold functions are placed to a special section, as they're
expected to be called rarely. This could help i-cache prefetches or help
compiler to decide which branches are more/less likely to be taken
without any other annotations needed.

Though we can't add more __exit annotations, it's still possible to add
__cold (that's also added with __exit). That way the following function
categories are tagged:

- printf wrappers, error messages
- exit helpers

Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26 15:09:39 +02:00
Linus Torvalds
31466f3ed7 for-4.16-tag
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Merge tag 'for-4.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Features or user visible changes:

   - fallocate: implement zero range mode

   - avoid losing data raid profile when deleting a device

   - tree item checker: more checks for directory items and xattrs

  Notable fixes:

   - raid56 recovery: don't use cached stripes, that could be
     potentially changed and a later RMW or recovery would lead to
     corruptions or failures

   - let raid56 try harder to rebuild damaged data, reading from all
     stripes if necessary

   - fix scrub to repair raid56 in a similar way as in the case above

  Other:

   - cleanups: device freeing, removed some call indirections, redundant
     bio_put/_get, unused parameters, refactorings and renames

   - RCU list traversal fixups

   - simplify mount callchain, remove recursing back when mounting a
     subvolume

   - plug for fsync, may improve bio merging on multiple devices

   - compression heurisic: replace heap sort with radix sort, gains some
     performance

   - add extent map selftests, buffered write vs dio"

* tag 'for-4.16-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (155 commits)
  btrfs: drop devid as device_list_add() arg
  btrfs: get device pointer from device_list_add()
  btrfs: set the total_devices in device_list_add()
  btrfs: move pr_info into device_list_add
  btrfs: make btrfs_free_stale_devices() to match the path
  btrfs: rename btrfs_free_stale_devices() arg to skip_dev
  btrfs: make btrfs_free_stale_devices() argument optional
  btrfs: make btrfs_free_stale_device() to iterate all stales
  btrfs: no need to check for btrfs_fs_devices::seeding
  btrfs: Use IS_ALIGNED in btrfs_truncate_block instead of opencoding it
  Btrfs: noinline merge_extent_mapping
  Btrfs: add WARN_ONCE to detect unexpected error from merge_extent_mapping
  Btrfs: extent map selftest: dio write vs dio read
  Btrfs: extent map selftest: buffered write vs dio read
  Btrfs: add extent map selftests
  Btrfs: move extent map specific code to extent_map.c
  Btrfs: add helper for em merge logic
  Btrfs: fix unexpected EEXIST from btrfs_get_extent
  Btrfs: fix incorrect block_len in merge_extent_mapping
  btrfs: Remove unused readahead spinlock
  ...
2018-01-29 14:04:23 -08:00
Jeff Layton
ae5e165d85 fs: new API for handling inode->i_version
Add a documentation blob that explains what the i_version field is, how
it is expected to work, and how it is currently implemented by various
filesystems.

We already have inode_inc_iversion. Add several other functions for
manipulating and accessing the i_version counter. For now, the
implementation is trivial and basically works the way that all of the
open-coded i_version accesses work today.

Future patches will convert existing users of i_version to use the new
API, and then convert the backend implementation to do things more
efficiently.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2018-01-29 06:41:30 -05:00
Filipe Manana
81fdf6382b Btrfs: fix space leak after fallocate and zero range operations
If we do a buffered write after a zero range operation that has an
unaligned (with the filesystem's sector size) end which also falls within
an unwritten (prealloc) extent that is currently beyond the inode's
i_size, and the zero range operation has the flag FALLOC_FL_KEEP_SIZE,
we end up leaking data and metadata space. This happens because when
zeroing a range we call btrfs_truncate_block(), which does delalloc
(loads the page and partially zeroes its content), and in the buffered
write path we only clear existing delalloc space reservation for the
range we are writing into if that range starts at an offset smaller then
the inode's i_size, which makes sense since we can not have delalloc
extents beyond the i_size, only unwritten extents are allowed.

Example reproducer:

 $ mkfs.btrfs -f /dev/sdb
 $ mount /dev/sdb /mnt
 $ xfs_io -f -c "falloc -k 428K 4K" /mnt/foobar
 $ xfs_io -c "fzero -k 0 430K" /mnt/foobar
 $ xfs_io -c "pwrite -S 0xaa 428K 4K" /mnt/foobar
 $ umount /mnt

After the unmount we get the metadata and data space leaks reported in
dmesg/syslog:

 [95794.602253] ------------[ cut here ]------------
 [95794.603322] WARNING: CPU: 0 PID: 31496 at fs/btrfs/inode.c:9561 btrfs_destroy_inode+0x4e/0x206 [btrfs]
 [95794.605167] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.613000] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.614448] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.615972] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.617114] RIP: 0010:btrfs_destroy_inode+0x4e/0x206 [btrfs]
 [95794.618001] RSP: 0018:ffffc90001737d00 EFLAGS: 00010202
 [95794.618721] RAX: 0000000000000000 RBX: ffff880070fa1418 RCX: ffffc90001737c7c
 [95794.619645] RDX: 0000000175aa0240 RSI: 0000000000000001 RDI: ffff880070fa1418
 [95794.620711] RBP: ffffc90001737d38 R08: 0000000000000000 R09: 0000000000000000
 [95794.621932] R10: ffffc90001737c48 R11: ffff88007123e158 R12: ffff880075b6a000
 [95794.623124] R13: ffff88006145c000 R14: ffff880070fa1418 R15: ffff880070c3b4a0
 [95794.624188] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.625578] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.626522] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.627647] Call Trace:
 [95794.628128]  destroy_inode+0x3d/0x55
 [95794.628573]  evict+0x177/0x17e
 [95794.629010]  dispose_list+0x50/0x71
 [95794.629478]  evict_inodes+0x132/0x141
 [95794.630289]  generic_shutdown_super+0x3f/0x10b
 [95794.630864]  kill_anon_super+0x12/0x1c
 [95794.631383]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.631930]  deactivate_locked_super+0x30/0x68
 [95794.632539]  deactivate_super+0x36/0x39
 [95794.633200]  cleanup_mnt+0x49/0x67
 [95794.633818]  __cleanup_mnt+0x12/0x14
 [95794.634416]  task_work_run+0x82/0xa6
 [95794.634902]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.635525]  syscall_return_slowpath+0x18c/0x1af
 [95794.636122]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.636834] RIP: 0033:0x7fa678cb99a7
 [95794.637370] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.638672] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.639596] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.640703] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.641773] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.643150] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.644249] Code: ff 4c 8b a8 80 06 00 00 48 8b 87 c0 01 00 00 48 85 c0 74 02 0f ff 48 83 bb e0 02 00 00 00 74 02 0f ff 83 bb 3c ff ff ff 00 74 02 <0f> ff 83 bb 40 ff ff ff 00 74 02 0f ff 48 83 bb f8 fe ff ff 00
 [95794.646929] ---[ end trace e95877675c6ec007 ]---
 [95794.647751] ------------[ cut here ]------------
 [95794.648509] WARNING: CPU: 0 PID: 31496 at fs/btrfs/inode.c:9562 btrfs_destroy_inode+0x59/0x206 [btrfs]
 [95794.649842] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.654659] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.655894] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.657546] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.658433] RIP: 0010:btrfs_destroy_inode+0x59/0x206 [btrfs]
 [95794.659279] RSP: 0018:ffffc90001737d00 EFLAGS: 00010202
 [95794.660054] RAX: 0000000000000000 RBX: ffff880070fa1418 RCX: ffffc90001737c7c
 [95794.660753] RDX: 0000000175aa0240 RSI: 0000000000000001 RDI: ffff880070fa1418
 [95794.661513] RBP: ffffc90001737d38 R08: 0000000000000000 R09: 0000000000000000
 [95794.662289] R10: ffffc90001737c48 R11: ffff88007123e158 R12: ffff880075b6a000
 [95794.663393] R13: ffff88006145c000 R14: ffff880070fa1418 R15: ffff880070c3b4a0
 [95794.664342] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.665673] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.666593] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.667629] Call Trace:
 [95794.668065]  destroy_inode+0x3d/0x55
 [95794.668637]  evict+0x177/0x17e
 [95794.669179]  dispose_list+0x50/0x71
 [95794.669830]  evict_inodes+0x132/0x141
 [95794.670416]  generic_shutdown_super+0x3f/0x10b
 [95794.671103]  kill_anon_super+0x12/0x1c
 [95794.671786]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.672552]  deactivate_locked_super+0x30/0x68
 [95794.673393]  deactivate_super+0x36/0x39
 [95794.674107]  cleanup_mnt+0x49/0x67
 [95794.674706]  __cleanup_mnt+0x12/0x14
 [95794.675279]  task_work_run+0x82/0xa6
 [95794.675795]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.676507]  syscall_return_slowpath+0x18c/0x1af
 [95794.677275]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.678006] RIP: 0033:0x7fa678cb99a7
 [95794.678600] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.679739] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.680779] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.681837] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.682867] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.683891] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.684843] Code: c0 01 00 00 48 85 c0 74 02 0f ff 48 83 bb e0 02 00 00 00 74 02 0f ff 83 bb 3c ff ff ff 00 74 02 0f ff 83 bb 40 ff ff ff 00 74 02 <0f> ff 48 83 bb f8 fe ff ff 00 74 02 0f ff 48 83 bb 00 ff ff ff
 [95794.687156] ---[ end trace e95877675c6ec008 ]---
 [95794.687876] ------------[ cut here ]------------
 [95794.688579] WARNING: CPU: 0 PID: 31496 at fs/btrfs/inode.c:9565 btrfs_destroy_inode+0x7d/0x206 [btrfs]
 [95794.689735] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.695015] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.696396] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.697956] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.698925] RIP: 0010:btrfs_destroy_inode+0x7d/0x206 [btrfs]
 [95794.699763] RSP: 0018:ffffc90001737d00 EFLAGS: 00010206
 [95794.700434] RAX: 0000000000000000 RBX: ffff880070fa1418 RCX: ffffc90001737c7c
 [95794.701445] RDX: 0000000175aa0240 RSI: 0000000000000001 RDI: ffff880070fa1418
 [95794.702448] RBP: ffffc90001737d38 R08: 0000000000000000 R09: 0000000000000000
 [95794.703557] R10: ffffc90001737c48 R11: ffff88007123e158 R12: ffff880075b6a000
 [95794.704441] R13: ffff88006145c000 R14: ffff880070fa1418 R15: ffff880070c3b4a0
 [95794.705270] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.706341] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.707001] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.708030] Call Trace:
 [95794.708466]  destroy_inode+0x3d/0x55
 [95794.709071]  evict+0x177/0x17e
 [95794.709497]  dispose_list+0x50/0x71
 [95794.709973]  evict_inodes+0x132/0x141
 [95794.710564]  generic_shutdown_super+0x3f/0x10b
 [95794.711200]  kill_anon_super+0x12/0x1c
 [95794.711633]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.712139]  deactivate_locked_super+0x30/0x68
 [95794.712608]  deactivate_super+0x36/0x39
 [95794.713093]  cleanup_mnt+0x49/0x67
 [95794.713514]  __cleanup_mnt+0x12/0x14
 [95794.713933]  task_work_run+0x82/0xa6
 [95794.714543]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.715247]  syscall_return_slowpath+0x18c/0x1af
 [95794.715952]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.716653] RIP: 0033:0x7fa678cb99a7
 [95794.721100] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.722052] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.722856] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.723698] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.724736] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.725928] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.726728] Code: 40 ff ff ff 00 74 02 0f ff 48 83 bb f8 fe ff ff 00 74 02 0f ff 48 83 bb 00 ff ff ff 00 74 02 0f ff 48 83 bb 30 ff ff ff 00 74 02 <0f> ff 48 83 bb 08 ff ff ff 00 74 02 0f ff 4d 85 e4 0f 84 52 01
 [95794.729203] ---[ end trace e95877675c6ec009 ]---
 [95794.841054] ------------[ cut here ]------------
 [95794.841829] WARNING: CPU: 0 PID: 31496 at fs/btrfs/extent-tree.c:5831 btrfs_free_block_groups+0x235/0x36a [btrfs]
 [95794.843425] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.850658] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.852590] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.854752] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.855812] RIP: 0010:btrfs_free_block_groups+0x235/0x36a [btrfs]
 [95794.856811] RSP: 0018:ffffc90001737d70 EFLAGS: 00010206
 [95794.857805] RAX: 0000000080000000 RBX: ffff88006145c000 RCX: 0000000000000001
 [95794.859014] RDX: 00000001810af668 RSI: 0000000000000002 RDI: 00000000ffffffff
 [95794.860270] RBP: ffffc90001737d98 R08: 0000000000000000 R09: ffffffff817e22b9
 [95794.861525] R10: ffffc90001737c80 R11: 00000000000337fd R12: 0000000000000000
 [95794.862700] R13: ffff88006145c0c0 R14: ffff88021b61a800 R15: ffff88006145c100
 [95794.863810] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.865149] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.866099] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.867198] Call Trace:
 [95794.867626]  close_ctree+0x1db/0x2b8 [btrfs]
 [95794.868188]  ? evict_inodes+0x132/0x141
 [95794.869037]  btrfs_put_super+0x15/0x17 [btrfs]
 [95794.870400]  generic_shutdown_super+0x6a/0x10b
 [95794.871262]  kill_anon_super+0x12/0x1c
 [95794.872046]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.872746]  deactivate_locked_super+0x30/0x68
 [95794.873687]  deactivate_super+0x36/0x39
 [95794.874639]  cleanup_mnt+0x49/0x67
 [95794.875504]  __cleanup_mnt+0x12/0x14
 [95794.876126]  task_work_run+0x82/0xa6
 [95794.876788]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.877777]  syscall_return_slowpath+0x18c/0x1af
 [95794.878381]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.878888] RIP: 0033:0x7fa678cb99a7
 [95794.879307] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.880204] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.881640] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.882690] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.883538] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.884562] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.885664] Code: 89 ef e8 07 ec 32 e1 e8 9d c0 ea e0 48 8d b3 28 02 00 00 48 83 c9 ff 31 d2 48 89 df e8 29 c5 ff ff 48 83 bb 80 02 00 00 00 74 02 <0f> ff 48 83 bb 88 02 00 00 00 74 02 0f ff 48 83 bb d8 02 00 00
 [95794.887980] ---[ end trace e95877675c6ec00a ]---
 [95794.888739] ------------[ cut here ]------------
 [95794.889405] WARNING: CPU: 0 PID: 31496 at fs/btrfs/extent-tree.c:5832 btrfs_free_block_groups+0x241/0x36a [btrfs]
 [95794.891020] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.897551] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.898509] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.899685] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.900592] RIP: 0010:btrfs_free_block_groups+0x241/0x36a [btrfs]
 [95794.901387] RSP: 0018:ffffc90001737d70 EFLAGS: 00010206
 [95794.902300] RAX: 0000000080000000 RBX: ffff88006145c000 RCX: 0000000000000001
 [95794.903260] RDX: 00000001810af668 RSI: 0000000000000002 RDI: 00000000ffffffff
 [95794.904332] RBP: ffffc90001737d98 R08: 0000000000000000 R09: ffffffff817e22b9
 [95794.905300] R10: ffffc90001737c80 R11: 00000000000337fd R12: 0000000000000000
 [95794.906439] R13: ffff88006145c0c0 R14: ffff88021b61a800 R15: ffff88006145c100
 [95794.907459] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.908625] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.909511] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.910630] Call Trace:
 [95794.911153]  close_ctree+0x1db/0x2b8 [btrfs]
 [95794.911837]  ? evict_inodes+0x132/0x141
 [95794.912344]  btrfs_put_super+0x15/0x17 [btrfs]
 [95794.912975]  generic_shutdown_super+0x6a/0x10b
 [95794.913788]  kill_anon_super+0x12/0x1c
 [95794.914424]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.915142]  deactivate_locked_super+0x30/0x68
 [95794.915831]  deactivate_super+0x36/0x39
 [95794.916433]  cleanup_mnt+0x49/0x67
 [95794.917045]  __cleanup_mnt+0x12/0x14
 [95794.917665]  task_work_run+0x82/0xa6
 [95794.918309]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.919021]  syscall_return_slowpath+0x18c/0x1af
 [95794.919722]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.920426] RIP: 0033:0x7fa678cb99a7
 [95794.921039] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.922303] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.923335] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.924364] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.925435] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.926533] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.927557] Code: 48 8d b3 28 02 00 00 48 83 c9 ff 31 d2 48 89 df e8 29 c5 ff ff 48 83 bb 80 02 00 00 00 74 02 0f ff 48 83 bb 88 02 00 00 00 74 02 <0f> ff 48 83 bb d8 02 00 00 00 74 02 0f ff 48 83 bb e0 02 00 00
 [95794.930166] ---[ end trace e95877675c6ec00b ]---
 [95794.930961] ------------[ cut here ]------------
 [95794.931727] WARNING: CPU: 0 PID: 31496 at fs/btrfs/extent-tree.c:9953 btrfs_free_block_groups+0x2bc/0x36a [btrfs]
 [95794.932729] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.938394] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.939842] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.941455] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.942336] RIP: 0010:btrfs_free_block_groups+0x2bc/0x36a [btrfs]
 [95794.943268] RSP: 0018:ffffc90001737d70 EFLAGS: 00010206
 [95794.944127] RAX: ffff8802004fd0e8 RBX: ffff88006145c000 RCX: 0000000000000001
 [95794.945211] RDX: 00000001810af668 RSI: 0000000000000002 RDI: 00000000ffffffff
 [95794.946316] RBP: ffffc90001737d98 R08: 0000000000000000 R09: ffffffff817e22b9
 [95794.947271] R10: ffffc90001737c80 R11: 00000000000337fd R12: ffff8802004fd0e8
 [95794.948219] R13: ffff88006145c0c0 R14: ffff88006145e598 R15: ffff88006145c100
 [95794.949193] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.950495] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.951338] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95794.952361] Call Trace:
 [95794.952811]  close_ctree+0x1db/0x2b8 [btrfs]
 [95794.953522]  ? evict_inodes+0x132/0x141
 [95794.954543]  btrfs_put_super+0x15/0x17 [btrfs]
 [95794.955231]  generic_shutdown_super+0x6a/0x10b
 [95794.955916]  kill_anon_super+0x12/0x1c
 [95794.956414]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95794.956953]  deactivate_locked_super+0x30/0x68
 [95794.957635]  deactivate_super+0x36/0x39
 [95794.958256]  cleanup_mnt+0x49/0x67
 [95794.958701]  __cleanup_mnt+0x12/0x14
 [95794.959181]  task_work_run+0x82/0xa6
 [95794.959635]  prepare_exit_to_usermode+0xe1/0x10c
 [95794.960182]  syscall_return_slowpath+0x18c/0x1af
 [95794.960731]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95794.961438] RIP: 0033:0x7fa678cb99a7
 [95794.961990] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95794.963111] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95794.963975] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95794.964680] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95794.965763] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95794.966868] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95794.967800] Code: 00 00 00 4c 8b a3 98 25 00 00 49 83 bc 24 60 ff ff ff 00 75 16 49 83 bc 24 68 ff ff ff 00 75 0b 49 83 bc 24 70 ff ff ff 00 74 16 <0f> ff 49 8d b4 24 18 ff ff ff 31 c9 31 d2 48 89 df e8 93 7a ff
 [95794.970629] ---[ end trace e95877675c6ec00c ]---
 [95794.971451] BTRFS info (device sdi): space_info 1 has 7680000 free, is not full
 [95794.972351] BTRFS info (device sdi): space_info total=8388608, used=704512, pinned=0, reserved=0, may_use=4096, readonly=0
 [95794.973595] ------------[ cut here ]------------
 [95794.974353] WARNING: CPU: 0 PID: 31496 at fs/btrfs/extent-tree.c:9953 btrfs_free_block_groups+0x2bc/0x36a [btrfs]
 [95794.980163] Modules linked in: btrfs xfs ppdev ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper parport_pc psmouse sg i2c_piix4 parport i2c_core evdev pcspkr button serio_raw sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sd_mod virtio_scsi ata_generic crc32c_intel ata_piix floppy virtio_pci virtio_ring virtio libata scsi_mod e1000 [last unloaded: btrfs]
 [95794.986461] CPU: 0 PID: 31496 Comm: umount Tainted: G        W       4.14.0-rc6-btrfs-next-54+ #1
 [95794.987591] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
 [95794.988929] task: ffff880075aa0240 task.stack: ffffc90001734000
 [95794.989922] RIP: 0010:btrfs_free_block_groups+0x2bc/0x36a [btrfs]
 [95794.990715] RSP: 0018:ffffc90001737d70 EFLAGS: 00010206
 [95794.991431] RAX: ffff88020f6e70e8 RBX: ffff88006145c000 RCX: ffffffff8115a906
 [95794.992455] RDX: ffffffff8115a902 RSI: ffff880075aa0b40 RDI: ffff880075aa0b40
 [95794.993535] RBP: ffffc90001737d98 R08: 0000000000000020 R09: fffffffffffffff7
 [95794.994573] R10: 00000000ffffffc4 R11: ffff8800633b1bc0 R12: ffff88020f6e70e8
 [95794.996250] R13: 0000000000000038 R14: ffff88006145e598 R15: 0000000000000000
 [95794.997233] FS:  00007fa6793c92c0(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
 [95794.998592] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [95794.999484] CR2: 000056338670d048 CR3: 00000000610dc005 CR4: 00000000001606f0
 [95795.000542] Call Trace:
 [95795.001138]  close_ctree+0x1db/0x2b8 [btrfs]
 [95795.001885]  ? evict_inodes+0x132/0x141
 [95795.002407]  btrfs_put_super+0x15/0x17 [btrfs]
 [95795.003093]  generic_shutdown_super+0x6a/0x10b
 [95795.003720]  kill_anon_super+0x12/0x1c
 [95795.004353]  btrfs_kill_super+0x16/0x21 [btrfs]
 [95795.005095]  deactivate_locked_super+0x30/0x68
 [95795.005716]  deactivate_super+0x36/0x39
 [95795.006388]  cleanup_mnt+0x49/0x67
 [95795.006939]  __cleanup_mnt+0x12/0x14
 [95795.007512]  task_work_run+0x82/0xa6
 [95795.008124]  prepare_exit_to_usermode+0xe1/0x10c
 [95795.008994]  syscall_return_slowpath+0x18c/0x1af
 [95795.009831]  entry_SYSCALL_64_fastpath+0xab/0xad
 [95795.010610] RIP: 0033:0x7fa678cb99a7
 [95795.011193] RSP: 002b:00007ffccf0aaed8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [95795.012327] RAX: 0000000000000000 RBX: 0000563386706030 RCX: 00007fa678cb99a7
 [95795.013432] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000056338670ca90
 [95795.014558] RBP: 000056338670ca90 R08: 000056338670c740 R09: 0000000000000015
 [95795.015577] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fa6791bae64
 [95795.016569] R13: 0000000000000000 R14: 0000563386706210 R15: 00007ffccf0ab160
 [95795.017662] Code: 00 00 00 4c 8b a3 98 25 00 00 49 83 bc 24 60 ff ff ff 00 75 16 49 83 bc 24 68 ff ff ff 00 75 0b 49 83 bc 24 70 ff ff ff 00 74 16 <0f> ff 49 8d b4 24 18 ff ff ff 31 c9 31 d2 48 89 df e8 93 7a ff
 [95795.020538] ---[ end trace e95877675c6ec00d ]---
 [95795.021259] BTRFS info (device sdi): space_info 4 has 1072775168 free, is not full
 [95795.022390] BTRFS info (device sdi): space_info total=1073741824, used=114688, pinned=0, reserved=0, may_use=786432, readonly=65536

Fix this by ensuring the zero range operation does not call
btrfs_truncate_block() if the corresponding extent is an unwritten one
(it's pointless anyway, since reading from an unwritten extent yields
zeroes).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:20 +01:00
Filipe Manana
9f13ce743b Btrfs: fix missing inode i_size update after zero range operation
For a fallocate's zero range operation that targets a range with an end
that is not aligned to the sector size, we can end up not updating the
inode's i_size. This happens when the last page of the range maps to an
unwritten (prealloc) extent and before that last page we have either a
hole or a written extent. This is because in this scenario we relied
on a call to btrfs_prealloc_file_range() to update the inode's i_size,
however it can only update the i_size to the "down aligned" end of the
range.

Example:

 $ mkfs.btrfs -f /dev/sdc
 $ mount /dev/sdc /mnt
 $ xfs_io -f -c "pwrite -S 0xff 0 428K" /mnt/foobar
 $ xfs_io -c "falloc -k 428K 4K" /mnt/foobar
 $ xfs_io -c "fzero 0 430K" /mnt/foobar
 $ du --bytes /mnt/foobar
 438272	/mnt/foobar

The inode's i_size was left as 428Kb (438272 bytes) when it should have
been updated to 430Kb (440320 bytes).
Fix this by always updating the inode's i_size explicitly after zeroing
the range.

Fixes: ba6d5887946ff86d93dc ("Btrfs: add support for fallocate's zero range operation")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:20 +01:00
Filipe Manana
94f450712a Btrfs: use cached state when dirtying pages during buffered write
During a buffered IO write, we can have an extent state that we got when
we locked the range (if the range starts at an offset lower than eof), so
always pass it to btrfs_dirty_pages() so that setting the delalloc bit
in the range does not need to do a full search in the inode's io tree,
saving time and reducing the amount of time we hold the io tree's lock.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:20 +01:00
Filipe Manana
f27451f229 Btrfs: add support for fallocate's zero range operation
This implements support the zero range operation of fallocate. For now
at least it's as simple as possible while reusing most of the existing
fallocate and hole punching infrastructure.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:20 +01:00
David Sterba
e43bbe5e16 btrfs: sink unlock_extent parameter gfp_flags
All callers pass either GFP_NOFS or GFP_KERNEL now, so we can sink the
parameter to the function, though we lose some of the slightly better
semantics of GFP_KERNEL in some places, it's worth cleaning up the
callchains.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:19 +01:00
Liu Bo
343e4fc1c6 Btrfs: set plug for fsync
Setting plug can merge adjacent IOs before dispatching IOs to the disk
driver.

Without plug, it'd not be a problem for single disk usecases, but for
multiple disks using raid profile, a large IO can be split to several
IOs of stripe length, and plug can be helpful to bring them together
for each disk so that we can save several disk access.

Moreover, fsync issues synchronous writes, so plug can really take
effect.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:13 +01:00
David Sterba
ae0f162534 btrfs: sink gfp parameter to clear_extent_bit
All callers use GFP_NOFS, we don't have to pass it as an argument. The
built-in tests pass GFP_KERNEL, but they run only at module load time
and NOFS works there as well.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:12 +01:00
Liu Bo
f5c29bd9db Btrfs: add __init macro to btrfs init functions
Adding __init macro gives kernel a hint that this function is only used
during the initialization phase and its memory resources can be freed up
after.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Nikolay Borisov
96b09dde92 btrfs: Use locked_end rather than open coding it
Right before we go into this loop locked_end is set to alloc_end - 1 and
is being used in nearby functions, no need to have exceptions. This just
makes the code consistent, no functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Nikolay Borisov
6b7d6e9334 btrfs: Move loop termination condition in while()
Fallocating a file in btrfs goes through several stages. The one before
actually inserting the fallocated extents is to create a qgroup
reservation, covering the desired range. To this end there is a loop in
btrfs_fallocate which checks to see if there are holes in the fallocated
range or !PREALLOC extents past EOF and if so create qgroup reservations
for them. Unfortunately, the main condition of the loop is burried right
at the end of its body rather than in the actual while statement which
makes it non-obvious. Fix this by moving the condition in the while
statement where it belongs. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-01-22 16:08:11 +01:00
Liu Bo
ebb70442cd Btrfs: fix list_add corruption and soft lockups in fsync
Xfstests btrfs/146 revealed this corruption,

[   58.138831] Buffer I/O error on dev dm-0, logical block 2621424, async page read
[   58.151233] BTRFS error (device sdf): bdev /dev/mapper/error-test errs: wr 1, rd 0, flush 0, corrupt 0, gen 0
[   58.152403] list_add corruption. prev->next should be next (ffff88005e6775d8), but was ffffc9000189be88. (prev=ffffc9000189be88).
[   58.153518] ------------[ cut here ]------------
[   58.153892] WARNING: CPU: 1 PID: 1287 at lib/list_debug.c:31 __list_add_valid+0x169/0x1f0
...
[   58.157379] RIP: 0010:__list_add_valid+0x169/0x1f0
...
[   58.161956] Call Trace:
[   58.162264]  btrfs_log_inode_parent+0x5bd/0xfb0 [btrfs]
[   58.163583]  btrfs_log_dentry_safe+0x60/0x80 [btrfs]
[   58.164003]  btrfs_sync_file+0x4c2/0x6f0 [btrfs]
[   58.164393]  vfs_fsync_range+0x5f/0xd0
[   58.164898]  do_fsync+0x5a/0x90
[   58.165170]  SyS_fsync+0x10/0x20
[   58.165395]  entry_SYSCALL_64_fastpath+0x1f/0xbe
...

It turns out that we could record btrfs_log_ctx:io_err in
log_one_extents when IO fails, but make log_one_extents() return '0'
instead of -EIO, so the IO error is not acknowledged by the callers,
i.e.  btrfs_log_inode_parent(), which would remove btrfs_log_ctx:list
from list head 'root->log_ctxs'.  Since btrfs_log_ctx is allocated
from stack memory, it'd get freed with a object alive on the
list. then a future list_add will throw the above warning.

This returns the correct error in the above case.

Jeff also reported this while testing against his fsync error
patch set[1].

[1]: https://www.spinics.net/lists/linux-btrfs/msg65308.html
"btrfs list corruption and soft lockups while testing writeback error handling"

Fixes: 8407f55326 ("Btrfs: fix data corruption after fast fsync and writeback error")
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-27 17:41:19 +01:00
Filipe Manana
e3b8a48585 Btrfs: fix reported number of inode blocks after buffered append writes
The patch from commit a7e3b975a0 ("Btrfs: fix reported number of inode
blocks") introduced a regression where if we do a buffered write starting
at position equal to or greater than the file's size and then stat(2) the
file before writeback is triggered, the number of used blocks does not
change (unless there's a prealloc/unwritten extent). Example:

  $ xfs_io -f -c "pwrite -S 0xab 0 64K" foobar
  $ du -h foobar
  0	foobar
  $ sync
  $ du -h foobar
  64K	foobar

The first version of that patch didn't had this regression and the second
version, which was the one committed, was made only to address some
performance regression detected by the intel test robots using fs_mark.

This fixes the regression by setting the new delaloc bit in the range, and
doing it at btrfs_dirty_pages() while setting the regular dealloc bit as
well, so that this way we set both bits at once avoiding navigation of the
inode's io tree twice. Doing it at btrfs_dirty_pages() is also the most
meaninful place, as we should set the new dellaloc bit when if we set the
delalloc bit, which happens only if we copied bytes into the pages at
__btrfs_buffered_write().

This was making some of LTP's du tests fail, which can be quickly run
using a command line like the following:

  $ ./runltp -q -p -l /ltp.log -f commands -s du -d /mnt

Fixes: a7e3b975a0 ("Btrfs: fix reported number of inode blocks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 17:27:46 +01:00
Filipe Manana
f48bf66b66 Btrfs: move definition of the function btrfs_find_new_delalloc_bytes
Move the definition of the function btrfs_find_new_delalloc_bytes() closer
to the function btrfs_dirty_pages(), because in a future commit it will be
used exclusively by btrfs_dirty_pages(). This just moves the function's
definition, with no functional changes at all.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-15 17:27:44 +01:00
Josef Bacik
8b62f87bad Btrfs: rework outstanding_extents
Right now we do a lot of weird hoops around outstanding_extents in order
to keep the extent count consistent.  This is because we logically
transfer the outstanding_extent count from the initial reservation
through the set_delalloc_bits.  This makes it pretty difficult to get a
handle on how and when we need to mess with outstanding_extents.

Fix this by revamping the rules of how we deal with outstanding_extents.
Now instead everybody that is holding on to a delalloc extent is
required to increase the outstanding extents count for itself.  This
means we'll have something like this

btrfs_delalloc_reserve_metadata	- outstanding_extents = 1
 btrfs_set_extent_delalloc	- outstanding_extents = 2
btrfs_release_delalloc_extents	- outstanding_extents = 1

for an initial file write.  Now take the append write where we extend an
existing delalloc range but still under the maximum extent size

btrfs_delalloc_reserve_metadata - outstanding_extents = 2
  btrfs_set_extent_delalloc
    btrfs_set_bit_hook		- outstanding_extents = 3
    btrfs_merge_extent_hook	- outstanding_extents = 2
btrfs_delalloc_release_extents	- outstanding_extnets = 1

In order to make the ordered extent transition we of course must now
make ordered extents carry their own outstanding_extent reservation, so
for cow_file_range we end up with

btrfs_add_ordered_extent	- outstanding_extents = 2
clear_extent_bit		- outstanding_extents = 1
btrfs_remove_ordered_extent	- outstanding_extents = 0

This makes all manipulations of outstanding_extents much more explicit.
Every successful call to btrfs_delalloc_reserve_metadata _must_ now be
combined with btrfs_release_delalloc_extents, even in the error case, as
that is the only function that actually modifies the
outstanding_extents counter.

The drawback to this is now we are much more likely to have transient
cases where outstanding_extents is much larger than it actually should
be.  This could happen before as we manipulated the delalloc bits, but
now it happens basically at every write.  This may put more pressure on
the ENOSPC flushing code, but I think making this code simpler is worth
the cost.  I have another change coming to mitigate this side-effect
somewhat.

I also added trace points for the counter manipulation.  These were used
by a bpf script I wrote to help track down leak issues.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01 20:45:35 +01:00
Goldwyn Rodrigues
79f015f216 btrfs: cleanup extent locking sequence
Code cleanup for better understanding:
Variable needs_unlock to be called extent_locked to show state as
opposed to action. Changed the type to int, to reduce code in the
critical path.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:01 +01:00
Josef Bacik
84f7d8e624 btrfs: pass root to various extent ref mod functions
We need the actual root for the ref verifier tool to work, so change
these functions to pass the root around instead.  This will be used in
a subsequent patch.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:28:00 +01:00
Thomas Meyer
897ca8194c btrfs: Fix bool initialization/comparison
Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-10-30 12:27:58 +01:00
Linus Torvalds
e253d98f5b Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull nowait read support from Al Viro:
 "Support IOCB_NOWAIT for buffered reads and block devices"

* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  block_dev: support RFW_NOWAIT on block device nodes
  fs: support RWF_NOWAIT for buffered reads
  fs: support IOCB_NOWAIT in generic_file_buffered_read
  fs: pass iocb to do_generic_file_read
2017-09-14 19:29:55 -07:00
Christoph Hellwig
91f9943e1c fs: support RWF_NOWAIT for buffered reads
This is based on the old idea and code from Milosz Tanski.  With the aio
nowait code it becomes mostly trivial now.  Buffered writes continue to
return -EOPNOTSUPP if RWF_NOWAIT is passed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-04 19:04:23 -04:00
Josef Bacik
23b5ec7494 btrfs: fix readdir deadlock with pagefault
Readdir does dir_emit while under the btree lock.  dir_emit can trigger
the page fault which means we can deadlock.  Fix this by allocating a
buffer on opening a directory and copying the readdir into this buffer
and doing dir_emit from outside of the tree lock.

Thread A
readdir  <holding tree lock>
  dir_emit
    <page fault>
      down_read(mmap_sem)

Thread B
mmap write
  down_write(mmap_sem)
    page_mkwrite
      wait_ordered_extents

Process C
finish_ordered_extent
  insert_reserved_file_extent
   try to lock leaf <hang>

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copy the deadlock scenario to changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:05 +02:00
David Sterba
ea14b57fd1 btrfs: fix spelling of snapshotting
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:04 +02:00
Linus Torvalds
6618a24ab2 Merge branch 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
 "This fixes a user-visible bug introduced by the nowait-aio patches
  merged in this cycle"

* 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: nowait aio: Correct assignment of pos
2017-07-10 10:27:48 -07:00
Goldwyn Rodrigues
ff0fa73247 btrfs: nowait aio: Correct assignment of pos
Assigning pos for usage early messes up in append mode, where the pos is
re-assigned in generic_write_checks(). Assign pos later to get the
correct position to write from iocb->ki_pos.

Since check_can_nocow also uses the value of pos, we shift
generic_write_checks() before check_can_nocow(). Checks with IOCB_DIRECT
are present in generic_write_checks(), so checking for IOCB_NOWAIT is
enough.

Also, put locking sequence in the fast path.

This fixes a user visible bug, as reported:

"apparently breaks several shell related features on my system.
In zsh history stopped working, because no new entries are added
anymore.
I fist noticed the issue when I tried to build mplayer. It uses a shell
script to generate a help_mp.h file:
[...]

Here is a simple testcase:

 % echo "foo" >> test
 % echo "foo" >> test
 % cat test
 foo
 %
"

Fixes: edf064e7c6 ("btrfs: nowait aio support")
CC: Jens Axboe <axboe@kernel.dk>
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Link: https://lkml.kernel.org/r/20170704042306.GA274@x4
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-10 15:29:44 +02:00
Linus Torvalds
088737f44b Writeback error handling fixes (pile #2)
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Merge tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull Writeback error handling updates from Jeff Layton:
 "This pile represents the bulk of the writeback error handling fixes
  that I have for this cycle. Some of the earlier patches in this pile
  may look trivial but they are prerequisites for later patches in the
  series.

  The aim of this set is to improve how we track and report writeback
  errors to userland. Most applications that care about data integrity
  will periodically call fsync/fdatasync/msync to ensure that their
  writes have made it to the backing store.

  For a very long time, we have tracked writeback errors using two flags
  in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a
  writeback error occurs (via mapping_set_error) and are cleared as a
  side-effect of filemap_check_errors (as you noted yesterday). This
  model really sucks for userland.

  Only the first task to call fsync (or msync or fdatasync) will see the
  error. Any subsequent task calling fsync on a file will get back 0
  (unless another writeback error occurs in the interim). If I have
  several tasks writing to a file and calling fsync to ensure that their
  writes got stored, then I need to have them coordinate with one
  another. That's difficult enough, but in a world of containerized
  setups that coordination may even not be possible.

  But wait...it gets worse!

  The calls to filemap_check_errors can be buried pretty far down in the
  call stack, and there are internal callers of filemap_write_and_wait
  and the like that also end up clearing those errors. Many of those
  callers ignore the error return from that function or return it to
  userland at nonsensical times (e.g. truncate() or stat()). If I get
  back -EIO on a truncate, there is no reason to think that it was
  because some previous writeback failed, and a subsequent fsync() will
  (incorrectly) return 0.

  This pile aims to do three things:

   1) ensure that when a writeback error occurs that that error will be
      reported to userland on a subsequent fsync/fdatasync/msync call,
      regardless of what internal callers are doing

   2) report writeback errors on all file descriptions that were open at
      the time that the error occurred. This is a user-visible change,
      but I think most applications are written to assume this behavior
      anyway. Those that aren't are unlikely to be hurt by it.

   3) document what filesystems should do when there is a writeback
      error. Today, there is very little consistency between them, and a
      lot of cargo-cult copying. We need to make it very clear what
      filesystems should do in this situation.

  To achieve this, the set adds a new data type (errseq_t) and then
  builds new writeback error tracking infrastructure around that. Once
  all of that is in place, we change the filesystems to use the new
  infrastructure for reporting wb errors to userland.

  Note that this is just the initial foray into cleaning up this mess.
  There is a lot of work remaining here:

   1) convert the rest of the filesystems in a similar fashion. Once the
      initial set is in, then I think most other fs' will be fairly
      simple to convert. Hopefully most of those can in via individual
      filesystem trees.

   2) convert internal waiters on writeback to use errseq_t for
      detecting errors instead of relying on the AS_* flags. I have some
      draft patches for this for ext4, but they are not quite ready for
      prime time yet.

  This was a discussion topic this year at LSF/MM too. If you're
  interested in the gory details, LWN has some good articles about this:

      https://lwn.net/Articles/718734/
      https://lwn.net/Articles/724307/"

* tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  btrfs: minimal conversion to errseq_t writeback error reporting on fsync
  xfs: minimal conversion to errseq_t writeback error reporting
  ext4: use errseq_t based error handling for reporting data writeback errors
  fs: convert __generic_file_fsync to use errseq_t based reporting
  block: convert to errseq_t based writeback error tracking
  dax: set errors in mapping when writeback fails
  Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors
  mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error
  fs: new infrastructure for writeback error handling and reporting
  lib: add errseq_t type and infrastructure for handling it
  mm: don't TestClearPageError in __filemap_fdatawait_range
  mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails
  jbd2: don't clear and reset errors after waiting on writeback
  buffer: set errors in mapping at the time that the error occurs
  fs: check for writeback errors after syncing out buffers in generic_file_fsync
  buffer: use mapping_set_error instead of setting the flag
  mm: fix mapping_set_error call in me_pagecache_dirty
2017-07-07 19:38:17 -07:00
Jeff Layton
333427a505 btrfs: minimal conversion to errseq_t writeback error reporting on fsync
Just check and advance the errseq_t in the file before returning, and
use an errseq_t based check for writeback errors.

Other internal callers of filemap_* functions are left as-is.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06 07:02:31 -04:00
Linus Torvalds
8c27cb3566 Merge branch 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
 "The core updates improve error handling (mostly related to bios), with
  the usual incremental work on the GFP_NOFS (mis)use removal,
  refactoring or cleanups. Except the two top patches, all have been in
  for-next for an extensive amount of time.

  User visible changes:

   - statx support

   - quota override tunable

   - improved compression thresholds

   - obsoleted mount option alloc_start

  Core updates:

   - bio-related updates:
       - faster bio cloning
       - no allocation failures
       - preallocated flush bios

   - more kvzalloc use, memalloc_nofs protections, GFP_NOFS updates

   - prep work for btree_inode removal

   - dir-item validation

   - qgoup fixes and updates

   - cleanups:
       - removed unused struct members, unused code, refactoring
       - argument refactoring (fs_info/root, caller -> callee sink)
       - SEARCH_TREE ioctl docs"

* 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (115 commits)
  btrfs: Remove false alert when fiemap range is smaller than on-disk extent
  btrfs: Don't clear SGID when inheriting ACLs
  btrfs: fix integer overflow in calc_reclaim_items_nr
  btrfs: scrub: fix target device intialization while setting up scrub context
  btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges
  btrfs: qgroup: Introduce extent changeset for qgroup reserve functions
  btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled
  btrfs: qgroup: Return actually freed bytes for qgroup release or free data
  btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents function
  btrfs: qgroup: Add quick exit for non-fs extents
  Btrfs: rework delayed ref total_bytes_pinned accounting
  Btrfs: return old and new total ref mods when adding delayed refs
  Btrfs: always account pinned bytes when dropping a tree block ref
  Btrfs: update total_bytes_pinned when pinning down extents
  Btrfs: make BUG_ON() in add_pinned_bytes() an ASSERT()
  Btrfs: make add_pinned_bytes() take an s64 num_bytes instead of u64
  btrfs: fix validation of XATTR_ITEM dir items
  btrfs: Verify dir_item in iterate_object_props
  btrfs: Check name_len before in btrfs_del_root_ref
  btrfs: Check name_len before reading btrfs_get_name
  ...
2017-07-05 16:41:23 -07:00
Qu Wenruo
bc42bda223 btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges
[BUG]
For the following case, btrfs can underflow qgroup reserved space
at an error path:
(Page size 4K, function name without "btrfs_" prefix)

         Task A                  |             Task B
----------------------------------------------------------------------
Buffered_write [0, 2K)           |
|- check_data_free_space()       |
|  |- qgroup_reserve_data()      |
|     Range aligned to page      |
|     range [0, 4K)          <<< |
|     4K bytes reserved      <<< |
|- copy pages to page cache      |
                                 | Buffered_write [2K, 4K)
                                 | |- check_data_free_space()
                                 | |  |- qgroup_reserved_data()
                                 | |     Range alinged to page
                                 | |     range [0, 4K)
                                 | |     Already reserved by A <<<
                                 | |     0 bytes reserved      <<<
                                 | |- delalloc_reserve_metadata()
                                 | |  And it *FAILED* (Maybe EQUOTA)
                                 | |- free_reserved_data_space()
                                      |- qgroup_free_data()
                                         Range aligned to page range
                                         [0, 4K)
                                         Freeing 4K
(Special thanks to Chandan for the detailed report and analyse)

[CAUSE]
Above Task B is freeing reserved data range [0, 4K) which is actually
reserved by Task A.

And at writeback time, page dirty by Task A will go through writeback
routine, which will free 4K reserved data space at file extent insert
time, causing the qgroup underflow.

[FIX]
For btrfs_qgroup_free_data(), add @reserved parameter to only free
data ranges reserved by previous btrfs_qgroup_reserve_data().
So in above case, Task B will try to free 0 byte, so no underflow.

Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo
364ecf3651 btrfs: qgroup: Introduce extent changeset for qgroup reserve functions
Introduce a new parameter, struct extent_changeset for
btrfs_qgroup_reserved_data() and its callers.

Such extent_changeset was used in btrfs_qgroup_reserve_data() to record
which range it reserved in current reserve, so it can free it in error
paths.

The reason we need to export it to callers is, at buffered write error
path, without knowing what exactly which range we reserved in current
allocation, we can free space which is not reserved by us.

This will lead to qgroup reserved space underflow.

Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Filipe Manana
609805d809 Btrfs: fix invalid extent maps due to hole punching
While punching a hole in a range that is not aligned with the sector size
(currently the same as the page size) we can end up leaving an extent map
in memory with a length that is smaller then the sector size or with a
start offset that is not aligned to the sector size. Both cases are not
expected and can lead to problems. This issue is easily detected
after the patch from commit a7e3b975a0 ("Btrfs: fix reported number of
inode blocks"), introduced in kernel 4.12-rc1, in a scenario like the
following for example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -c "pwrite -S 0xaa -b 100K 0 100K" /mnt/foo
  $ xfs_io -c "fpunch 60K 90K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xbb -b 100K 50K 100K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xcc -b 50K 100K 50K" /mnt/foo
  $ umount /mnt

After the unmount operation we can see several warnings emmitted due to
underflows related to space reservation counters:

[ 2837.443299] ------------[ cut here ]------------
[ 2837.447395] WARNING: CPU: 8 PID: 2474 at fs/btrfs/inode.c:9444 btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.452108] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button se
rio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_gene
ric raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.458389] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.459754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.462379] Call Trace:
[ 2837.462379]  dump_stack+0x68/0x92
[ 2837.462379]  __warn+0xc2/0xdd
[ 2837.462379]  warn_slowpath_null+0x1d/0x1f
[ 2837.462379]  btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.462379]  destroy_inode+0x3d/0x55
[ 2837.462379]  evict+0x177/0x17e
[ 2837.462379]  dispose_list+0x50/0x71
[ 2837.462379]  evict_inodes+0x132/0x141
[ 2837.462379]  generic_shutdown_super+0x3f/0xeb
[ 2837.462379]  kill_anon_super+0x12/0x1c
[ 2837.462379]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.462379]  deactivate_locked_super+0x30/0x68
[ 2837.462379]  deactivate_super+0x36/0x39
[ 2837.462379]  cleanup_mnt+0x58/0x76
[ 2837.462379]  __cleanup_mnt+0x12/0x14
[ 2837.462379]  task_work_run+0x77/0x9b
[ 2837.462379]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.462379]  syscall_return_slowpath+0x196/0x1b9
[ 2837.462379]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.462379] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.462379] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.462379] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.462379] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.462379] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.462379] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.462379] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.519355] ---[ end trace e79345fe24b30b8d ]---
[ 2837.596256] ------------[ cut here ]------------
[ 2837.597625] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5699 btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.603547] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.659372] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.663359] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.663359] Call Trace:
[ 2837.663359]  dump_stack+0x68/0x92
[ 2837.663359]  __warn+0xc2/0xdd
[ 2837.663359]  warn_slowpath_null+0x1d/0x1f
[ 2837.663359]  btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.663359]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.663359]  ? evict_inodes+0x132/0x141
[ 2837.663359]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.663359]  generic_shutdown_super+0x6a/0xeb
[ 2837.663359]  kill_anon_super+0x12/0x1c
[ 2837.663359]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.663359]  deactivate_locked_super+0x30/0x68
[ 2837.663359]  deactivate_super+0x36/0x39
[ 2837.663359]  cleanup_mnt+0x58/0x76
[ 2837.663359]  __cleanup_mnt+0x12/0x14
[ 2837.663359]  task_work_run+0x77/0x9b
[ 2837.663359]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.663359]  syscall_return_slowpath+0x196/0x1b9
[ 2837.663359]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.663359] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.663359] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.663359] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.663359] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.663359] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.663359] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.663359] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.739445] ---[ end trace e79345fe24b30b8e ]---
[ 2837.745595] ------------[ cut here ]------------
[ 2837.746412] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5700 btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.747955] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.755395] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.756769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.758526] Call Trace:
[ 2837.758925]  dump_stack+0x68/0x92
[ 2837.759383]  __warn+0xc2/0xdd
[ 2837.759383]  warn_slowpath_null+0x1d/0x1f
[ 2837.759383]  btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.759383]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.759383]  ? evict_inodes+0x132/0x141
[ 2837.759383]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.759383]  generic_shutdown_super+0x6a/0xeb
[ 2837.759383]  kill_anon_super+0x12/0x1c
[ 2837.759383]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.759383]  deactivate_locked_super+0x30/0x68
[ 2837.759383]  deactivate_super+0x36/0x39
[ 2837.759383]  cleanup_mnt+0x58/0x76
[ 2837.759383]  __cleanup_mnt+0x12/0x14
[ 2837.759383]  task_work_run+0x77/0x9b
[ 2837.759383]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.759383]  syscall_return_slowpath+0x196/0x1b9
[ 2837.759383]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.759383] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.759383] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.759383] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.759383] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.759383] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.759383] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.759383] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.777063] ---[ end trace e79345fe24b30b8f ]---
[ 2837.778235] ------------[ cut here ]------------
[ 2837.778856] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:9825 btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.791385] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.797711] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.798594] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.800118] Call Trace:
[ 2837.800515]  dump_stack+0x68/0x92
[ 2837.801015]  __warn+0xc2/0xdd
[ 2837.801471]  warn_slowpath_null+0x1d/0x1f
[ 2837.801698]  btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.801698]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.801698]  ? evict_inodes+0x132/0x141
[ 2837.801698]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.801698]  generic_shutdown_super+0x6a/0xeb
[ 2837.801698]  kill_anon_super+0x12/0x1c
[ 2837.801698]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.801698]  deactivate_locked_super+0x30/0x68
[ 2837.801698]  deactivate_super+0x36/0x39
[ 2837.801698]  cleanup_mnt+0x58/0x76
[ 2837.801698]  __cleanup_mnt+0x12/0x14
[ 2837.801698]  task_work_run+0x77/0x9b
[ 2837.801698]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.801698]  syscall_return_slowpath+0x196/0x1b9
[ 2837.801698]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.801698] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.801698] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.801698] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.801698] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.801698] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.801698] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.801698] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.818441] ---[ end trace e79345fe24b30b90 ]---
[ 2837.818991] BTRFS info (device sdc): space_info 1 has 7974912 free, is not full
[ 2837.819830] BTRFS info (device sdc): space_info total=8388608, used=417792, pinned=0, reserved=0, may_use=18446744073709547520, readonly=0

What happens in the above example is the following:

1) When punching the hole, at btrfs_punch_hole(), the variable tail_len
   is set to 2048 (as tail_start is 148Kb + 1 and offset + len is 150Kb).
   This results in the creation of an extent map with a length of 2Kb
   starting at file offset 148Kb, through find_first_non_hole() ->
   btrfs_get_extent().

2) The second write (first write after the hole punch operation), sets
   the range [50Kb, 152Kb[ to delalloc.

3) The third write, at btrfs_find_new_delalloc_bytes(), sees the extent
   map covering the range [148Kb, 150Kb[ and ends up calling
   set_extent_bit() for the same range, which results in splitting an
   existing extent state record, covering the range [148Kb, 152Kb[ into
   two 2Kb extent state records, covering the ranges [148Kb, 150Kb[ and
   [150Kb, 152Kb[.

4) Finally at lock_and_cleanup_extent_if_need(), immediately after calling
   btrfs_find_new_delalloc_bytes() we clear the delalloc bit from the
   range [100Kb, 152Kb[ which results in the btrfs_clear_bit_hook()
   callback being invoked against the two 2Kb extent state records that
   cover the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. When called against
   the first 2Kb extent state, it calls btrfs_delalloc_release_metadata()
   with a length argument of 2048 bytes. That function rounds up the length
   to a sector size aligned length, so it ends up considering a length of
   4096 bytes, and then calls calc_csum_metadata_size() which results in
   decrementing the inode's csum_bytes counter by 4096 bytes, so after
   it stays a value of 0 bytes. Then the same happens when
   btrfs_clear_bit_hook() is called against the second extent state that
   has a length of 2Kb, covering the range [150Kb, 152Kb[, the length is
   rounded up to 4096 and calc_csum_metadata_size() ends up being called
   to decrement 4096 bytes from the inode's csum_bytes counter, which
   at that time has a value of 0, leading to an underflow, which is
   exactly what triggers the first warning, at btrfs_destroy_inode().
   All the other warnings relate to several space accounting counters
   that underflow as well due to similar reasons.

A similar case but where the hole punching operation creates an extent map
with a start offset not aligned to the sector size is the following:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -f -c "fpunch 695K 820K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xaa 1008K 307K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xbb -b 630K 1073K 630K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xcc -b 459K 1068K 459K" $SCRATCH_MNT/bar
  $ umount /mnt

During the unmount operation we get similar traces for the same reasons as
in the first example.

So fix the hole punching operation to make sure it never creates extent
maps with a length that is not aligned to the sector size nor with a start
offset that is not aligned to the sector size, as this breaks all
assumptions and it's a land mine.

Fixes: d77815461f ("btrfs: Avoid trucating page or punching hole in a already existed hole.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 16:52:45 +02:00
Goldwyn Rodrigues
edf064e7c6 btrfs: nowait aio support
Return EAGAIN if any of the following checks fail
 + i_rwsem is not lockable
 + NODATACOW or PREALLOC is not set
 + Cannot nocow at the desired location
 + Writing beyond end of file which is not allocated

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 07:12:03 -06:00
Chris Mason
bce19f9d23 Merge branch 'for-chris-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.12 2017-04-27 14:13:09 -07:00
Filipe Manana
a7e3b975a0 Btrfs: fix reported number of inode blocks
Currently when there are buffered writes that were not yet flushed and
they fall within allocated ranges of the file (that is, not in holes or
beyond eof assuming there are no prealloc extents beyond eof), btrfs
simply reports an incorrect number of used blocks through the stat(2)
system call (or any of its variants), regardless of mount options or
inode flags (compress, compress-force, nodatacow). This is because the
number of blocks used that is reported is based on the current number
of bytes in the vfs inode plus the number of dealloc bytes in the btrfs
inode. The later covers bytes that both fall within allocated regions
of the file and holes.

Example scenarios where the number of reported blocks is wrong while the
buffered writes are not flushed:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ xfs_io -f -c "pwrite -S 0xaa 0 64K" /mnt/sdc/foo1
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (259.336 MiB/sec and 66390.0415 ops/sec)

  $ sync

  $ xfs_io -c "pwrite -S 0xbb 0 64K" /mnt/sdc/foo1
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (192.308 MiB/sec and 49230.7692 ops/sec)

  # The following should have reported 64K...
  $ du -h /mnt/sdc/foo1
  128K	/mnt/sdc/foo1

  $ sync

  # After flushing the buffered write, it now reports the correct value.
  $ du -h /mnt/sdc/foo1
  64K	/mnt/sdc/foo1

  $ xfs_io -f -c "falloc -k 0 128K" -c "pwrite -S 0xaa 0 64K" /mnt/sdc/foo2
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (520.833 MiB/sec and 133333.3333 ops/sec)

  $ sync

  $ xfs_io -c "pwrite -S 0xbb 64K 64K" /mnt/sdc/foo2
  wrote 65536/65536 bytes at offset 65536
  64 KiB, 16 ops; 0.0000 sec (260.417 MiB/sec and 66666.6667 ops/sec)

  # The following should have reported 128K...
  $ du -h /mnt/sdc/foo2
  192K	/mnt/sdc/foo2

  $ sync

  # After flushing the buffered write, it now reports the correct value.
  $ du -h /mnt/sdc/foo2
  128K	/mnt/sdc/foo2

So the number of used file blocks is simply incorrect, unlike in other
filesystems such as ext4 and xfs for example, but only while the buffered
writes are not flushed.

Fix this by tracking the number of delalloc bytes that fall within holes
and beyond eof of a file, and use instead this new counter when reporting
the number of used blocks for an inode.

Another different problem that exists is that the delalloc bytes counter
is reset when writeback starts (by clearing the EXTENT_DEALLOC flag from
the respective range in the inode's iotree) and the vfs inode's bytes
counter is only incremented when writeback finishes (through
insert_reserved_file_extent()). Therefore while writeback is ongoing we
simply report a wrong number of blocks used by an inode if the write
operation covers a range previously unallocated. While this change does
not fix this problem, it does minimizes it a lot by shortening that time
window, as the new dealloc bytes counter (new_delalloc_bytes) is only
decremented when writeback finishes right before updating the vfs inode's
bytes counter. Fully fixing this second problem is not trivial and will
be addressed later by a different patch.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-04-26 16:27:26 +01:00
Filipe Manana
be2d253cc9 Btrfs: fix extent map leak during fallocate error path
If the call to btrfs_qgroup_reserve_data() failed, we were leaking an
extent map structure. The failure can happen either due to an -ENOMEM
condition or, when quotas are enabled, due to -EDQUOT for example.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
2017-04-26 16:27:24 +01:00
Dan Carpenter
9986277e0e Btrfs: handle only applicable errors returned by btrfs_get_extent
btrfs_get_extent() never returns NULL pointers, so this code introduces
a static checker warning.

The btrfs_get_extent() is a bit complex, but trust me that it doesn't
return NULLs and also if it did we would trigger the BUG_ON(!em) before
the last return statement.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ updated subject ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:27 +02:00