For extent_io tree's we have carried the address_mapping of the inode
around in the io tree in order to pull the inode back out for calling
into various tree ops hooks.  This works fine when everything that has
an extent_io_tree has an inode.  But we are going to remove the
btree_inode, so we need to change this.  Instead just have a generic
void * for private data that we can initialize with, and have all the
tree ops use that instead.  This had a lot of cascading changes but
should be relatively straightforward.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor reordering of the callback prototypes ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This patch adds the read-write attribute quota_override into sysfs.
Any process which has CAP_SYS_RESOURCE can set this flag to on, and
once it is set to true, processes with CAP_SYS_RESOURCE can exceed
the quota.
Signed-off-by: NSargun Dhillon <sargun@sargun.me>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This patch introduces the quota override flag to btrfs_fs_info, and a
change to quota limit checking code to temporarily allow for quota to be
overridden for processes with CAP_SYS_RESOURCE.

It's useful for administrative programs, such as log rotation, that may
need to temporarily use more disk space in order to free up a greater
amount of overall disk space without yielding more disk space to the
rest of userland.

Eventually, we may want to add the idea of an operator-specific quota,
operator reserved space, or something else to allow for administrative
override, but this is perhaps the simplest solution.
Signed-off-by: NSargun Dhillon <sargun@sargun.me>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The ->free_chunk_space variable is used to track the unallocated space
and access to it is protected by a spinlock, which is not used for
anything else.  Make the code a bit self-explanatory by switching the
variable to an atomic64_t type and kill the spinlock.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
[ not a performance critical code, use of atomic type is ok ]
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This adds comments to the flush error handling part of the code, and
hopes to maintain the same logic with a framework which can be used to
handle the errors at the volume level.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

These FIXMEs were already addressed in 2013. All functions check for
qgroup existence:

* btrfs_add_qgroup_relation
* btrfs_ioctl_qgroup_create
* btrfs_limit_qgroup
* btrfs_del_qgroup_relation
Signed-off-by: NDaichou <tommy0705c@gmail.com>
[ enhance and reformat changelog ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

"item" is never used.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Remove NULL test on kmap() as it will always return a valid pointer.
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_calc_trans_metadata_size() does an unsigned 32-bit multiplication,
which can overflow if num_items >= 4 GB / (nodesize * BTRFS_MAX_LEVEL * 2).
For a nodesize of 16kB, this overflow happens at 16k items. Usually,
num_items is a small constant passed to btrfs_start_transaction(), but
we also use btrfs_calc_trans_metadata_size() for metadata reservations
for extent items in btrfs_delalloc_{reserve,release}_metadata().

In drop_outstanding_extents(), num_items is calculated as
inode->reserved_extents - inode->outstanding_extents. The difference
between these two counters is usually small, but if many delalloc
extents are reserved and then the outstanding extents are merged in
btrfs_merge_extent_hook(), the difference can become large enough to
overflow in btrfs_calc_trans_metadata_size().

The overflow manifests itself as a leak of a multiple of 4 GB in
delalloc_block_rsv and the metadata bytes_may_use counter. This in turn
can cause early ENOSPC errors. Additionally, these WARN_ONs in
extent-tree.c will be hit when unmounting:

    WARN_ON(fs_info->delalloc_block_rsv.size > 0);
    WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
    WARN_ON(space_info->bytes_pinned > 0 ||
            space_info->bytes_reserved > 0 ||
            space_info->bytes_may_use > 0);

Fix it by casting nodesize to a u64 so that
btrfs_calc_trans_metadata_size() does a full 64-bit multiplication.
While we're here, do the same in btrfs_calc_trunc_metadata_size(); this
can't overflow with any existing uses, but it's better to be safe here
than have another hard-to-debug problem later on.

Cc: stable@vger.kernel.org
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

Before this, we use 'filled' mode here, ie. if all range has been
filled with EXTENT_DEFRAG bits, get to clear it, but if the defrag
range joins the adjacent delalloc range, then we'll have EXTENT_DEFRAG
bits in extent_state until releasing this inode's pages, and that
prevents extent_data from being freed.

This clears the bit if any was found within the ordered extent.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

In verify_dir_item, it wants to printk name_len of dir_item but
printk data_len acutally.

Fix it by calling btrfs_dir_name_len instead of btrfs_dir_data_len.
Signed-off-by: NSu Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory.  The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.

It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.

For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:

        return  %i7+8
         lduw   [%o5+16], %o0   ! MEM[(u32 *)__shash_desc.1_10 + 16B],

%o5 holds the base of the on-stack area allocated for the shash
descriptor.  But the return released the stack frame and the
register window.

So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.

Add a data compiler barrier to work around this problem.  This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)

With crucial insight from Eric Sandeen.

Cc: <stable@vger.kernel.org>
Reported-by: NAnatoly Pugachev <matorola@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

If we have to recover relocation during mount, we'll ultimately have to
evict the orphan inode.  That goes through the reservation dance, where
priority_reclaim_metadata_space and flush_space expect fs_info->fs_root
to be valid.  That's the next thing to be set up during mount, so we
crash, almost always in flush_space trying to join the transaction
but priority_reclaim_metadata_space is possible as well.  This call
path has been problematic in the past WRT whether ->fs_root is valid
yet.  Commit 957780eb (Btrfs: introduce ticketed enospc
infrastructure) added new users that are called in the direct path
instead of the async path that had already been worked around.

The thing is that we don't actually need the fs_root, specifically, for
anything.  We either use it to determine whether the root is the
chunk_root for use in choosing an allocation profile or as a root to pass
btrfs_join_transaction before immediately committing it.  Anything that
isn't the chunk root works in the former case and any root works in
the latter.

A simple fix is to use a root we know will always be there: the
extent_root.

Cc: <stable@vger.kernel.org> # v4.8+
Fixes: 957780eb (Btrfs: introduce ticketed enospc infrastructure)
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

If we fail to add the space_info kobject, we'll leak the memory
for the percpu counter.

Fixes: 6ab0a202 (btrfs: publish allocation data in sysfs)
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Variables start_idx and end_idx are supposed to hold a page index
derived from the file offsets. The int type is not the right one though,
offsets larger than 1 << 44 will get silently trimmed off the high bits.
(1 << 44 is 16TiB)

What can go wrong, if start is below the boundary and end gets trimmed:
- if there's a page after start, we'll find it (radix_tree_gang_lookup_slot)
- the final check "if (page->index <= end_idx)" will unexpectedly fail

The function will return false, ie. "there's no page in the range",
although there is at least one.

btrfs_page_exists_in_range is used to prevent races in:

* in hole punching, where we make sure there are not pages in the
  truncated range, otherwise we'll wait for them to finish and redo
  truncation, but we're going to replace the pages with holes anyway so
  the only problem is the intermediate state

* lock_extent_direct: we want to make sure there are no pages before we
  lock and start DIO, to prevent stale data reads

For practical occurence of the bug, there are several constaints.  The
file must be quite large, the affected range must cross the 16TiB
boundary and the internal state of the file pages and pending operations
must match.  Also, we must not have started any ordered data in the
range, otherwise we don't even reach the buggy function check.

DIO locking tries hard in several places to avoid deadlocks with
buffered IO and avoids waiting for ranges. The worst consequence seems
to be stale data read.

CC: Liu Bo <bo.li.liu@oracle.com>
CC: stable@vger.kernel.org	# 3.16+
Fixes: fc4adbff ("btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking")
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The setting of return code ret should be based on the error code
passed into function end_extent_writepage and not on ret. Thanks
to Liu Bo for spotting this mistake in the original fix I submitted.

Detected by CoverityScan, CID#1414312 ("Logically dead code")

Fixes: 5dca6eea ("Btrfs: mark mapping with error flag to report errors to userspace")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit b685d3d6 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

CC: David Sterba <dsterba@suse.com>
CC: linux-btrfs@vger.kernel.org
Fixes: b685d3d6Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

[BUG]
Cycle mount btrfs can cause fiemap to return different result.
Like:
 # mount /dev/vdb5 /mnt/btrfs
 # dd if=/dev/zero bs=16K count=4 oflag=dsync of=/mnt/btrfs/file
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        25088..25215       128   0x1
 # umount /mnt/btrfs
 # mount /dev/vdb5 /mnt/btrfs
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..31]:         25088..25119        32   0x0
   1: [32..63]:        25120..25151        32   0x0
   2: [64..95]:        25152..25183        32   0x0
   3: [96..127]:       25184..25215        32   0x1
But after above fiemap, we get correct merged result if we call fiemap
again.
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        25088..25215       128   0x1

[REASON]
Btrfs will try to merge extent map when inserting new extent map.

btrfs_fiemap(start=0 len=(u64)-1)
|- extent_fiemap(start=0 len=(u64)-1)
   |- get_extent_skip_holes(start=0 len=64k)
   |  |- btrfs_get_extent_fiemap(start=0 len=64k)
   |     |- btrfs_get_extent(start=0 len=64k)
   |        |  Found on-disk (ino, EXTENT_DATA, 0)
   |        |- add_extent_mapping()
   |        |- Return (em->start=0, len=16k)
   |
   |- fiemap_fill_next_extent(logic=0 phys=X len=16k)
   |
   |- get_extent_skip_holes(start=0 len=64k)
   |  |- btrfs_get_extent_fiemap(start=0 len=64k)
   |     |- btrfs_get_extent(start=16k len=48k)
   |        |  Found on-disk (ino, EXTENT_DATA, 16k)
   |        |- add_extent_mapping()
   |        |  |- try_merge_map()
   |        |     Merge with previous em start=0 len=16k
   |        |     resulting em start=0 len=32k
   |        |- Return (em->start=0, len=32K)    << Merged result
   |- Stripe off the unrelated range (0~16K) of return em
   |- fiemap_fill_next_extent(logic=16K phys=X+16K len=16K)
      ^^^ Causing split fiemap extent.

And since in add_extent_mapping(), em is already merged, in next
fiemap() call, we will get merged result.

[FIX]
Here we introduce a new structure, fiemap_cache, which records previous
fiemap extent.

And will always try to merge current fiemap_cache result before calling
fiemap_fill_next_extent().
Only when we failed to merge current fiemap extent with cached one, we
will call fiemap_fill_next_extent() to submit cached one.

So by this method, we can merge all fiemap extents.

It can also be done in fs/ioctl.c, however the problem is if
fieinfo->fi_extents_max == 0, we have no space to cache previous fiemap
extent.
So I choose to merge it in btrfs.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

__vmalloc* allows users to provide gfp flags for the underlying
allocation.  This API is quite popular

  $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l
  77

The only problem is that many people are not aware that they really want
to give __GFP_HIGHMEM along with other flags because there is really no
reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages
which are mapped to the kernel vmalloc space.  About half of users don't
use this flag, though.  This signals that we make the API unnecessarily
too complex.

This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to
be mapped to the vmalloc space.  Current users which add __GFP_HIGHMEM
are simplified and drop the flag.

Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NMatthew Wilcox <mawilcox@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Cristopher Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are many code paths opencoding kvmalloc.  Let's use the helper
instead.  The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator.  E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation.  This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously.  There is no guarantee something like that happens
though.

This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.

Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commits cc8385b5 and 7ef70b4d added preallocation for the
reada radix trees and also switched them over to GFP_KERNEL for the
default gfp mask.

Since we're doing radix tree insertions under spinlocks, we need
to make sure the mask doesn't allow sleeping.  This fix keeps
the radix preallocation but switches back to the original gfp_mask.
Reported-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NChris Mason <clm@fb.com>

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: NFilipe Manana <fdmanana@suse.com>

Normally we don't have inline extents followed by regular extents, but
there's currently at least one harmless case where this happens. For
example, when the page size is 4Kb and compression is enabled:

  $ mkfs.btrfs -f /dev/sdb
  $ mount -o compress /dev/sdb /mnt
  $ xfs_io -f -c "pwrite -S 0xaa 0 4K" -c "fsync" /mnt/foobar
  $ xfs_io -c "pwrite -S 0xbb 8K 4K" -c "fsync" /mnt/foobar

In this case we get a compressed inline extent, representing 4Kb of
data, followed by a hole extent and then a regular data extent. The
inline extent was not expanded/converted to a regular extent exactly
because it represents 4Kb of data. This does not cause any apparent
problem (such as the issue solved by commit e1699d2d
("btrfs: add missing memset while reading compressed inline extents"))
except trigger an unexpected case in the incremental send code path
that makes us issue an operation to write a hole when it's not needed,
resulting in more writes at the receiver and wasting space at the
receiver.

So teach the incremental send code to deal with this particular case.

The issue can be currently triggered by running fstests btrfs/137 with
compression enabled (MOUNT_OPTIONS="-o compress" ./check btrfs/137).
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>

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: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>

When using compression, if we fail to insert an inline extent we
incorrectly end up attempting to free the reserved data space twice,
once through extent_clear_unlock_delalloc(), because we pass it the
flag EXTENT_DO_ACCOUNTING, and once through a direct call to
btrfs_free_reserved_data_space_noquota(). This results in a trace
like the following:

[  834.576240] ------------[ cut here ]------------
[  834.576825] WARNING: CPU: 2 PID: 486 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  834.579501] Modules linked in: btrfs crc32c_generic xor raid6_pq ppdev i2c_piix4 acpi_cpufreq psmouse tpm_tis parport_pc pcspkr serio_raw tpm_tis_core sg parport evdev i2c_core tpm button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs]
[  834.592116] CPU: 2 PID: 486 Comm: kworker/u32:4 Not tainted 4.10.0-rc8-btrfs-next-37+ #2
[  834.593316] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  834.595273] Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs]
[  834.596103] Call Trace:
[  834.596103]  dump_stack+0x67/0x90
[  834.596103]  __warn+0xc2/0xdd
[  834.596103]  warn_slowpath_null+0x1d/0x1f
[  834.596103]  btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  834.596103]  compress_file_range.constprop.42+0x2fa/0x3fc [btrfs]
[  834.596103]  ? submit_compressed_extents+0x3a7/0x3a7 [btrfs]
[  834.596103]  async_cow_start+0x32/0x4d [btrfs]
[  834.596103]  btrfs_scrubparity_helper+0x187/0x3e7 [btrfs]
[  834.596103]  btrfs_delalloc_helper+0xe/0x10 [btrfs]
[  834.596103]  process_one_work+0x273/0x4e4
[  834.596103]  worker_thread+0x1eb/0x2ca
[  834.596103]  ? rescuer_thread+0x2b6/0x2b6
[  834.596103]  kthread+0x100/0x108
[  834.596103]  ? __list_del_entry+0x22/0x22
[  834.596103]  ret_from_fork+0x2e/0x40
[  834.611656] ---[ end trace 719902fe6bdef08f ]---

So fix this by not calling directly btrfs_free_reserved_data_space_noquota()
if an error happened.
Signed-off-by: NFilipe Manana <fdmanana@suse.com>

When attempting to COW a file range (we are starting writeback and doing
COW), if we manage to reserve an extent for the range we will write into
but fail after reserving it and before creating the respective ordered
extent, we end up in an error path where we attempt to decrement the
data space's bytes_may_use counter after we already did it while
reserving the extent, leading to a warning/trace like the following:

[  847.621524] ------------[ cut here ]------------
[  847.625441] WARNING: CPU: 5 PID: 4905 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  847.633704] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq i2c_piix4 ppdev psmouse tpm_tis serio_raw pcspkr parport_pc tpm_tis_core i2c_core sg
[  847.644616] CPU: 5 PID: 4905 Comm: xfs_io Not tainted 4.10.0-rc8-btrfs-next-37+ #2
[  847.648601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  847.648601] Call Trace:
[  847.648601]  dump_stack+0x67/0x90
[  847.648601]  __warn+0xc2/0xdd
[  847.648601]  warn_slowpath_null+0x1d/0x1f
[  847.648601]  btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  847.648601]  btrfs_clear_bit_hook+0x140/0x258 [btrfs]
[  847.648601]  clear_state_bit+0x87/0x128 [btrfs]
[  847.648601]  __clear_extent_bit+0x222/0x2b7 [btrfs]
[  847.648601]  clear_extent_bit+0x17/0x19 [btrfs]
[  847.648601]  extent_clear_unlock_delalloc+0x3b/0x6b [btrfs]
[  847.648601]  cow_file_range.isra.39+0x387/0x39a [btrfs]
[  847.648601]  run_delalloc_nocow+0x4d7/0x70e [btrfs]
[  847.648601]  ? arch_local_irq_save+0x9/0xc
[  847.648601]  run_delalloc_range+0xa7/0x2b5 [btrfs]
[  847.648601]  writepage_delalloc.isra.31+0xb9/0x15c [btrfs]
[  847.648601]  __extent_writepage+0x249/0x2e8 [btrfs]
[  847.648601]  extent_write_cache_pages.constprop.33+0x28b/0x36c [btrfs]
[  847.648601]  ? arch_local_irq_save+0x9/0xc
[  847.648601]  ? mark_lock+0x24/0x201
[  847.648601]  extent_writepages+0x4b/0x5c [btrfs]
[  847.648601]  ? btrfs_writepage_start_hook+0xed/0xed [btrfs]
[  847.648601]  btrfs_writepages+0x28/0x2a [btrfs]
[  847.648601]  do_writepages+0x23/0x2c
[  847.648601]  __filemap_fdatawrite_range+0x5a/0x61
[  847.648601]  filemap_fdatawrite_range+0x13/0x15
[  847.648601]  btrfs_fdatawrite_range+0x20/0x46 [btrfs]
[  847.648601]  start_ordered_ops+0x19/0x23 [btrfs]
[  847.648601]  btrfs_sync_file+0x136/0x42c [btrfs]
[  847.648601]  vfs_fsync_range+0x8c/0x9e
[  847.648601]  vfs_fsync+0x1c/0x1e
[  847.648601]  do_fsync+0x31/0x4a
[  847.648601]  SyS_fsync+0x10/0x14
[  847.648601]  entry_SYSCALL_64_fastpath+0x18/0xad
[  847.648601] RIP: 0033:0x7f5b05200800
[  847.648601] RSP: 002b:00007ffe204f71c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
[  847.648601] RAX: ffffffffffffffda RBX: ffffffff8109637b RCX: 00007f5b05200800
[  847.648601] RDX: 00000000008bd0a0 RSI: 00000000008bd2e0 RDI: 0000000000000003
[  847.648601] RBP: ffffc90001d67f98 R08: 000000000000ffff R09: 000000000000001f
[  847.648601] R10: 00000000000001f6 R11: 0000000000000246 R12: 0000000000000046
[  847.648601] R13: ffffc90001d67f78 R14: 00007f5b054be740 R15: 00007f5b054be740
[  847.648601]  ? trace_hardirqs_off_caller+0x3f/0xaa
[  847.685787] ---[ end trace 2a4a3e15382508e8 ]---

So fix this by not attempting to decrement the data space info's
bytes_may_use counter if we already reserved the extent and an error
happened before creating the ordered extent. We are already correctly
freeing the reserved extent if an error happens, so there's no additional
measure needed.
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>

[BUG]
If run_delalloc_range() returns error and there is already some ordered
extents created, btrfs will be hanged with the following backtrace:

Call Trace:
 __schedule+0x2d4/0xae0
 schedule+0x3d/0x90
 btrfs_start_ordered_extent+0x160/0x200 [btrfs]
 ? wake_atomic_t_function+0x60/0x60
 btrfs_run_ordered_extent_work+0x25/0x40 [btrfs]
 btrfs_scrubparity_helper+0x1c1/0x620 [btrfs]
 btrfs_flush_delalloc_helper+0xe/0x10 [btrfs]
 process_one_work+0x2af/0x720
 ? process_one_work+0x22b/0x720
 worker_thread+0x4b/0x4f0
 kthread+0x10f/0x150
 ? process_one_work+0x720/0x720
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x2e/0x40

[CAUSE]

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<>|                       |<---------- cleanup range --------->|
 ||
 \_=> First page handled by end_extent_writepage() in __extent_writepage()

The problem is caused by error handler of run_delalloc_range(), which
doesn't handle any created ordered extents, leaving them waiting on
btrfs_finish_ordered_io() to finish.

However after run_delalloc_range() returns error, __extent_writepage()
won't submit bio, so btrfs_writepage_end_io_hook() won't be triggered
except the first page, and btrfs_finish_ordered_io() won't be triggered
for created ordered extents either.

So OE 2~n will hang forever, and if OE 1 is larger than one page, it
will also hang.

[FIX]
Introduce btrfs_cleanup_ordered_extents() function to cleanup created
ordered extents and finish them manually.

The function is based on existing
btrfs_endio_direct_write_update_ordered() function, and modify it to
act just like btrfs_writepage_endio_hook() but handles specified range
other than one page.

After fix, delalloc error will be handled like:

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<>|<--------  ----------->|<------ old error handler --------->|
 ||          ||
 ||          \_=> Cleaned up by cleanup_ordered_extents()
 \_=> First page handled by end_extent_writepage() in __extent_writepage()
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>

[BUG]
When btrfs_reloc_clone_csum() reports error, it can underflow metadata
and leads to kernel assertion on outstanding extents in
run_delalloc_nocow() and cow_file_range().

 BTRFS info (device vdb5): relocating block group 12582912 flags data
 BTRFS info (device vdb5): found 1 extents
 assertion failed: inode->outstanding_extents >= num_extents, file: fs/btrfs//extent-tree.c, line: 5858

Currently, due to another bug blocking ordered extents, the bug is only
reproducible under certain block group layout and using error injection.

a) Create one data block group with one 4K extent in it.
   To avoid the bug that hangs btrfs due to ordered extent which never
   finishes
b) Make btrfs_reloc_clone_csum() always fail
c) Relocate that block group

[CAUSE]
run_delalloc_nocow() and cow_file_range() handles error from
btrfs_reloc_clone_csum() wrongly:

(The ascii chart shows a more generic case of this bug other than the
bug mentioned above)

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
                    |<----------- cleanup range --------------->|
|<-----------  ----------->|
             \/
 btrfs_finish_ordered_io() range

So error handler, which calls extent_clear_unlock_delalloc() with
EXTENT_DELALLOC and EXTENT_DO_ACCOUNT bits, and btrfs_finish_ordered_io()
will both cover OE n, and free its metadata, causing metadata under flow.

[Fix]
The fix is to ensure after calling btrfs_add_ordered_extent(), we only
call error handler after increasing the iteration offset, so that
cleanup range won't cover any created ordered extent.

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<-----------  ----------->|<---------- cleanup range --------->|
             \/
 btrfs_finish_ordered_io() range
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>

Allocate struct backing_dev_info separately instead of embedding it
inside superblock. This unifies handling of bdi among users.

CC: Chris Mason <clm@fb.com>
CC: Josef Bacik <jbacik@fb.com>
CC: David Sterba <dsterba@suse.com>
CC: linux-btrfs@vger.kernel.org
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

The WARN_ON and warning from report_reserved_underflow can become very
noisy and is visible unconditionally although this is namely for
debugging. The patch "btrfs: Add WARN_ON for qgroup reserved underflow"
(18dc22c1) went to 4.11-rc1 and the plan
was to get the fix as well, but this hasn't happened.

CC: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The block layer call chain from submit_bio will check if the write cache
is enabled for the given queue before submitting the flush. This will
add a code to fail fast if its not.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ updated changelog to reflect current code stat, blkdev_issue_flush is
  not used yet ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The last consumer of nobarriers is removed by the commit [1] and sync
won't fail with EOPNOTSUPP anymore. Thus, now when write cache is write
through it just return success without actually transpiring such a
request to the block device/lun.

[1]
commit b25de9d6
block: remove BIO_EOPNOTSUPP

And, as the device/lun write cache state may change dynamically saving
such as state won't help either. So deleting the member nobarriers.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

When scrubbing a RAID5 which has recoverable data corruption (only one
data stripe is corrupted), sometimes scrub will report more csum errors
than expected. Sometimes even unrecoverable error will be reported.

The problem can be easily reproduced by the following steps:
1) Create a btrfs with RAID5 data profile with 3 devs
2) Mount it with nospace_cache or space_cache=v2
   To avoid extra data space usage.
3) Create a 128K file and sync the fs, unmount it
   Now the 128K file lies at the beginning of the data chunk
4) Locate the physical bytenr of data chunk on dev3
   Dev3 is the 1st data stripe.
5) Corrupt the first 64K of the data chunk stripe on dev3
6) Mount the fs and scrub it

The correct csum error number should be 16 (assuming using x86_64).
Larger csum error number can be reported in a 1/3 chance.
And unrecoverable error can also be reported in a 1/10 chance.

The root cause of the problem is RAID5/6 recover code has race
condition, due to the fact that full scrub is initiated per device.

While for other mirror based profiles, each mirror is independent with
each other, so race won't cause any big problem.

For example:
        Corrupted       |       Correct          |      Correct        |
|   Scrub dev3 (D1)     |    Scrub dev2 (D2)     |    Scrub dev1(P)    |
------------------------------------------------------------------------
Read out D1             |Read out D2             |Read full stripe     |
Check csum              |Check csum              |Check parity         |
Csum mismatch           |Csum match, continue    |Parity mismatch      |
handle_errored_block    |                        |handle_errored_block |
 Read out full stripe   |                        | Read out full stripe|
 D1 csum error(err++)   |                        | D1 csum error(err++)|
 Recover D1             |                        | Recover D1          |

So D1's csum error is accounted twice, just because
handle_errored_block() doesn't have enough protection, and race can happen.

On even worse case, for example D1's recovery code is re-writing
D1/D2/P, and P's recovery code is just reading out full stripe, then we
can cause unrecoverable error.

This patch will use previously introduced lock_full_stripe() and
unlock_full_stripe() to protect the whole scrub_handle_errored_block()
function for RAID56 recovery.
So no extra csum error nor unrecoverable error.
Reported-by: NGoffredo Baroncelli <kreijack@libero.it>
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Unlike mirror based profiles, RAID5/6 recovery needs to read out the
whole full stripe.

And if we don't do proper protection, it can easily cause race condition.

Introduce 2 new functions: lock_full_stripe() and unlock_full_stripe()
for RAID5/6.
Which store a rb_tree of mutexes for full stripes, so scrub callers can
use them to lock a full stripe to avoid race.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor comment adjustments ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_root_item maintains the ctime for root updates.  This is not part
of vfs_inode.

Since current_time() uses struct inode* as an argument as Linus
suggested, this cannot be used to update root times unless, we modify
the signature to use inode.

Since btrfs uses nanosecond time granularity, it can also use
ktime_get_real_ts directly to obtain timestamp for the root. It is
necessary to use the timespec time api here because the same
btrfs_set_stack_timespec_*() apis are used for vfs inode times as well.
These can be transitioned to using timespec64 when btrfs internally
changes to use timespec64 as well.
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Acked-by: NDavid Sterba <dsterba@suse.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

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: NDan Carpenter <dan.carpenter@oracle.com>
[ updated subject ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

[BUG]
The easist way to reproduce the bug is:
------
 # mkfs.btrfs -f $dev -n 16K
 # mount $dev $mnt -o inode_cache
 # btrfs quota enable $mnt
 # btrfs quota rescan -w $mnt
 # btrfs qgroup show $mnt
qgroupid         rfer         excl
--------         ----         ----
0/5          32.00KiB     32.00KiB
             ^^ Twice the correct value
------

And fstests/btrfs qgroup test group can easily detect them with
inode_cache mount option.
Although some of them are false alerts since old test cases are using
fixed golden output.
While new test cases will use "btrfs check" to detect qgroup mismatch.

[CAUSE]
Inode_cache mount option will make commit_fs_roots() to call
btrfs_save_ino_cache() to update fs/subvol trees, and generate new
delayed refs.

However we call btrfs_qgroup_prepare_account_extents() too early, before
commit_fs_roots().
This makes the "old_roots" for newly generated extents are always NULL.
For freeing extent case, this makes both new_roots and old_roots to be
empty, while correct old_roots should not be empty.
This causing qgroup numbers not decreased correctly.

[FIX]
Modify the timing of calling btrfs_qgroup_prepare_account_extents() to
just before btrfs_qgroup_account_extents(), and add needed delayed_refs
handler.
So qgroup can handle inode_map mount options correctly.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We have already assigned q from bdev_get_queue() so use it.
And rearrange the code for better view.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This is fixing code pieces where we use div_u64 when passing a u64 divisor.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit 3d8da678 ("Btrfs: fix divide error upon chunk's stripe_len")
changed stripe_len in struct map_lookup to u64, but didn't update
stripe_len in struct scrub_parity.

This updates the type and switches to div64_u64_rem to match u64 divisor.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>