Block layer has a limit on plug, ie. BLK_MAX_REQUEST_COUNT == 16, so
we don't gain benefits by batching 64 bios here.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

If we're still going to wait after schedule(), we don't have to do
finish_wait() to remove our %wait_queue_entry since prepare_to_wait()
won't add the same %wait_queue_entry twice.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Since TASK_UNINTERRUPTIBLE has been used here, wait_event() can do the
same job.

Signed-off-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Both wait_for_commit() and wait_for_writer() are checking the
condition out of the mutex lock.

This refactors code a bit to be lock safe.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Some static functions are needlessly forward declared. Let's remove those
declarations since they add no value.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

So that perf can show the state symbol.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

These aren't used outside of volumes.c.

Signed-off-by: Omar Sandoval <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Signed-off-by: Omar Sandoval <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We didn't copy fsid to struct super_block.s_uuid so Overlay disables
index feature with btrfs as the lower FS.

kernel: overlayfs: fs on '/lower' does not support file handles, falling back to index=off.

Fix this by publishing the fsid through struct super_block.s_uuid.

[ dsterba: I think that setting s_uuid is the last missing bit. Overlay
  needs the file handle encoding support from the lower filesystem, which
  is supported. Filling the whole filesystem id is correct, the subvolume
  id is encoded in the file handle buffer from inside btrfs_encode_fh. ]

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

After mapping block with BTRFS_MAP_WRITE, parities have been sorted to
the end position, so this search can start from the first parity
stripe.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ copied changelog as a comment ]
Signed-off-by: David Sterba <[email protected]>

While we submit direct writes, if the inode is flagged with nodatasum,
there's no benefit to submit asynchronously, because

a) we don't have to calculate checksum across processors,

b) and direct IO has started a plug, but async submit makes us queue
IO on each device's scheduled IO list instead of DIO's plug list, so
that IOs get much less merges in general.

Lets use sync submit for nodatasum inodes.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Src was initially part of 31ff1cd ("Btrfs: Copy into the log tree in
big batches"), however 16e7549 ("Btrfs: incompatible format change
to remove hole extents") changed parameters passed to copy_items which
made the src variable redundant.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Timofey Titovets <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

iterate_dir_item:found_key - introduced in 31db9f7 ("Btrfs:
  introduce BTRFS_IOC_SEND for btrfs send/receive"), yet never used.

record_ref:num - ditto

This is a first pass with the low-hanging fruit. There are still quite a
few unsued parameters in some function which have to abide by a callback
interface.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

btrfs_changed_cb_t represents the signature of the callback being passed
to btrfs_compare_trees. Currently there is only one such callback,
namely changed_cb in send.c. This function doesn't really uses the first
2 parameters, i.e. the roots. Since there are not other functions
implementing the btrfs_changed_cb_t let's remove the unused parameters
from the prototype and implementation.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Introduced by 5a5f79b ("Btrfs: allow unaligned DIO") and never
used. The buffered fallback from unaligned DIO works as expected.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Timofey Titovets <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

…hunk

Currently the code executes add_extent_mapping and if it is successful
it links the new mapping, it then proceeds to unlock the extent mapping
tree and check for failure and handle them. Instead, rework the code to
only perform a single check if add_extent_mapping has failed and handle
it, otherwise the code continues in a linear fashion. No functional
changes

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

__link_block_group is called from only 2 places and at each call site the
space_info being passed is the same as the space info assigned to the passed
cache struct. Let's remove the redundant argument and make the function
reference the space_info from the passed block_group_cache. No functional
changes

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ renamed to link_block_group ]
Signed-off-by: David Sterba <[email protected]>

If 'btrfs_alloc_path()' fails, we must free the resources already
allocated, as done in the other error handling paths in this function.

Signed-off-by: Christophe JAILLET <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

The value of variable 'can_recover' is never used after being set, thus
it should be removed, as it was never used since the first commit
68a7342 ("Btrfs: cleanup orphaned root orphan item").

Signed-off-by: Christos Gkekas <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

There are checks on fs_info in __btrfs_panic to avoid dereferencing a
null fs_info, however, there is a call to btrfs_crit that may also
dereference a null fs_info. Fix this by adding a check to see if fs_info
is null and only print the s_id if fs_info is non-null.

Detected by CoverityScan CID#401973 ("Dereference after null check")

Fixes: efe120a ("Btrfs: convert printk to btrfs_ and fix BTRFS prefix")
Signed-off-by: Colin Ian King <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Signed-off-by: Satoru Takeuchi <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We have started plug in btrfs_write_and_wait_marked_extents() but the
generated IOs actually go to device's schedule IO list where the work
is doing in another task, thus the started plug doesn't make any
sense.

And since we wait for IOs immediately after writing meta blocks, it's
the same case as writing log tree, doing sync submit can merge more
IOs.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Since both committing transaction and writing log-tree are doing
plugging on metadata IO, we can unify to use %sync_writers to benefit
both cases, instead of checking bio_flags while writing meta blocks of
log-tree.

We can remove this bio_flags because in order to write dirty blocks,
log tree also uses btrfs_write_marked_extents(), inside which we
have enabled %sync_writers, therefore, every write goes in a
synchronous way, so does checksuming.

Please also note that, bio_flags is applied per-context while
%sync_writers is applied per-inode, so this might incur some overhead, ie.

1) while log tree is flushing its dirty blocks via
   btrfs_write_marked_extents(), in which %sync_writers is increased
   by one.

2) in the meantime, some writeback operations may happen upon btrfs's
   metadata inode, so these writes go synchronously, too.

However, AFAICS, the overhead is not a big one while the win is that
we unify the two places that needs synchronous way and remove a
special hack/flag.

This removes the bio_flags related stuff for writing log-tree.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We've seen the following backtrace stack in ftrace or dmesg log,

  kworker/u16:10-4244  [000] 241942.480955: function:             btrfs_put_ordered_extent
  kworker/u16:10-4244  [000] 241942.480956: kernel_stack:         <stack trace>
=> finish_ordered_fn (ffffffffa0384475)
=> btrfs_scrubparity_helper (ffffffffa03ca577)        <-----"incorrect"
=> btrfs_freespace_write_helper (ffffffffa03ca98e)    <-----"correct"
=> process_one_work (ffffffff81117b2f)
=> worker_thread (ffffffff81118c2a)
=> kthread (ffffffff81121de0)
=> ret_from_fork (ffffffff81d7087a)

btrfs_freespace_write_helper is actually calling normal_worker_helper
instead of btrfs_scrubparity_helper, so somehow kernel has parsed the
incorrect function address while unwinding the stack,
btrfs_scrubparity_helper really shouldn't be shown up.

It's caused by compiler doing inline for our helper function, adding a
noinline tag can fix that.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ use noinline_for_stack ]
Signed-off-by: David Sterba <[email protected]>

Forward the correct return value -ENOMEM from btrfsic_dev_state_alloc()
too.

Signed-off-by: Allen Pais <[email protected]>
Reviewed-by: Anand Jain <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ adjust changelog ]
Signed-off-by: David Sterba <[email protected]>

Don't populate the read-only array types on the stack, instead make
it static const.  Makes the object code smaller by nearly 60 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  90536	   6552	     64	  97152	  17b80	fs/btrfs/ioctl.o

After:
   text	   data	    bss	    dec	    hex	filename
  90414	   6616	     64	  97094	  17b46	fs/btrfs/ioctl.o

Signed-off-by: Colin Ian King <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

The local bio_list may have pending bios when doing cleanup, it can
end up with memory leak if they don't get freed.

Signed-off-by: Liu Bo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

…read

By analyzing the perf on btrfs send, we found it take large amount of
cpu time on page_cache_sync_readahead. This effort can be reduced after
switching to asynchronous one. Overall performance gain on HDD and SSD
were 9 and 15 percent if simply send a large file.

Signed-off-by: Kuanling Huang <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Nikolay reported that generic/273 was failing currently with ENOSPC.
Turns out this is because we get to the point where the outstanding
reservations are greater than the pinned space on the fs.  This is a
mistake, previously we used the current reservation amount in
may_commit_transaction, not the entire outstanding reservation amount.
Fix this to find the minimum byte size needed to make progress in
flushing, and pass that into may_commit_transaction.  From there we can
make a smarter decision on whether to commit the transaction or not.
This fixes the failure in generic/273.

From Nikolai, IOW: when we go to the final stage of deciding whether to
do trans commit, instead of passing all the reservations from all
tickets we just pass the reservation for the current ticket. Otherwise,
in case all reservations exceed pinned space, then we don't commit
transaction and fail prematurely. Before we passed num_bytes from
flush_space, where num_bytes was the sum of all pending reserverations,
but now all we do is take the first ticket and commit the trans if we
can satisfy that.

Fixes: 957780e ("Btrfs: introduce ticketed enospc infrastructure")
Cc: [email protected] # 4.8
Reported-by: Nikolay Borisov <[email protected]>
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Tested-by: Nikolay Borisov <[email protected]>
[ added Nikolai's comment ]
Signed-off-by: David Sterba <[email protected]>

Was added in:
  c8b9781
  "Btrfs: Add zlib compression support"
Survive to near time (from 08.10.2008).

Because 'start' checked for zero before branch, so it's safe to remove
that subtraction.

Signed-off-by: Timofey Titovets <[email protected]>
Reviewed-by: Satoru Takeuchi <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Current check_leaf() function does a good job checking key order and
item offset/size.

However it only checks from slot 0 to the last but one slot, this is
good but makes later expansion hard.

So this refactoring iterates from slot 0 to the last slot.
For key comparison, it uses a key with all 0 as initial key, so all
valid keys should be larger than that.

And for item size/offset checks, it compares current item end with
previous item offset.
For slot 0, use leaf end as a special case.

This makes later item/key offset checks and item size checks easier to
be implemented.

Also, makes check_leaf() to return -EUCLEAN other than -EIO to indicate
error.

Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Function check_leaf() checks if any item pointer points outside of the
leaf, but it doesn't check if the pointer overlaps with the item itself.

Normally only the last item may be the victim, but adding such check is
never a bad idea anyway.

Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Add extra checks for item with EXTENT_DATA type.  This checks the
following thing:

0) Key offset
   All key offsets must be aligned to sectorsize.
   Inline extent must have 0 for key offset.

1) Item size
   Uncompressed inline file extent size must match item size.
   (Compressed inline file extent has no information about its on-disk size.)
   Regular/preallocated file extent size must be a fixed value.

2) Every member of regular file extent item
   Including alignment for bytenr and offset, possible value for
   compression/encryption/type.

3) Type/compression/encode must be one of the valid values.

This should be the most comprehensive and strict check in the context
of btrfs_item for EXTENT_DATA.

Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ switch to BTRFS_FILE_EXTENT_TYPES, similar to what
  BTRFS_COMPRESS_TYPES does ]
Signed-off-by: David Sterba <[email protected]>

EXTENT_CSUM checker is a relatively easy one, only needs to check:

1) Objectid
   Fixed to BTRFS_EXTENT_CSUM_OBJECTID

2) Key offset alignment
   Must be aligned to sectorsize

3) Item size alignedment
   Must be aligned to csum size

Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

When new device is being added to seed FS, seed FS is marked writable,
but when we fail to bring in the new device, we missed to undo the
writable part. This patch fixes it.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Instead of BUG_ON return error to the caller. And handle the fail
condition by calling the abort transaction and going through the
error path.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

btrfs_init_new_device() calls btrfs_attach_transaction() to
commit sys chunks, and it should error out if it fails.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

btrfs_udpate_root can fail and it aborts the transaction, the correct
way to handle an aborted transaction is to explicitly end with
btrfs_end_transaction.  Even now the code is correct since
btrfs_commit_transaction would handle an aborted transaction but this is
more of an implementation detail. So let's be explicit in handling
failure in btrfs_update_root.

Furthermore btrfs_commit_transaction can also fail and by ignoring it's
return value we could have left the in-memory copy of the root item in
an inconsistent state. So capture the error value which allows us to
correctly revert the RO/RW flags in case of commit failure.

Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

If btrfs_transaction_commit fails it will proceed to call
cleanup_transaction, which in turn already does btrfs_abort_transaction.
So let's remove the unnecessary code duplication. Also let's be explicit
about handling failure of btrfs_uuid_tree_add by calling
btrfs_end_transaction.

Signed-off-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Currently struct names for sysfs are generated only based on the
attribute names. This means that attribute names cannot be reused in
multiple places throughout the complete btrfs sysfs hierarchy.

E.g. allocation/data/total_bytes and allocation/data/single/total_bytes
result in the same struct name btrfs_attr_total_bytes. A workaround for
this case was made in the past by ad hoc creating an extra macro
wrapper, BTRFS_RAID_ATTR, that inserts some extra text in the struct
name.

Instead of polluting sysfs.h with such kind of extra macro definitions,
and only doing so when there are collisions, use a prefix which gets
inserted in the struct name, so we keep everything nicely grouped
together by default.

Current collections of attributes are:
* (the toplevel, empty prefix)
* allocation
* space_info
* raid
* features

Signed-off-by: Hans van Kranenburg <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Commit a53f4f8 ("btrfs: Don't call btrfs_start_transaction() on
frozen fs to avoid deadlock.") started using internal calls and we
replace them with more suitable ones.

Signed-off-by: Rakesh Pandit <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Remove dead assigment of num_bytes.

Also as num_bytes only used in the will_compress block as copy of
total_in just replace that with total_in and drop num_bytes entirely.

Signed-off-by: Timofey Titovets <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

It's no doubt the comprehensive tree block checker will become larger,
so moving them into their own files is quite reasonable.

Signed-off-by: Qu Wenruo <[email protected]>
[ wording adjustments ]
Signed-off-by: David Sterba <[email protected]>

Use inline function to replace macro since we don't need
stringification.
(Macro still exists until all callers get updated)

And add more info about the error, and replace EIO with EUCLEAN.

For nr_items error, report if it's too large or too small, and output
the valid value range.

For node block pointer, added a new alignment checker.

For key order, also output the next key to make the problem more
obvious.

Signed-off-by: Qu Wenruo <[email protected]>
[ wording adjustments, unindented long strings ]
Signed-off-by: David Sterba <[email protected]>

Enhance the output to print:
1) the eason
2) the ad value, if reason is not sufficient
3) good value (range)

Signed-off-by: Qu Wenruo <[email protected]>
[ wording, unidented long strings ]
Signed-off-by: David Sterba <[email protected]>

Output the bad value and expected good value (or its alignment).

Signed-off-by: Qu Wenruo <[email protected]>
[ unindent long strings ]
Signed-off-by: David Sterba <[email protected]>

Output the invalid member name and its bad value, along with its
expected value range or alignment.

Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

This was intended to congest higher layers to not send bios, but as

1) the congested bit has been taken by writeback

Async bios come from buffered writes and DIO writes.

For DIO writes, we want to submit them ASAP, while for buffered writes,
writeback uses balance_dirty_pages() to throttle how much dirty pages we
can have.

2) and no one is waiting for %nr_async_bios down to zero,

Historically, it was introduced along with changes which let
checksumming workload spread accross different cpus.  And at that time,
pdflush was used instead of per-bdi flushing, perhaps pdflush did not
have the necessary information for writeback to do throttling.

We can safely remove them now.

Signed-off-by: Liu Bo <[email protected]>
[ additional explanation from mails, removed unused variable 'limit' ]
Signed-off-by: David Sterba <[email protected]>

By setting compression for a defrag task, the task will start IO at
the end of defrag.

After the combo of filemap_flush(), we've already made sure that
dirty pages have made progress via async compress thread because the
second filemap_flush() will wait for page lock, which won't be
unlocked until those pages have been marked as writeback and ordered
extents have been queued.

And this is for per-inode defrag, it's not helpful to wait on a global
%async_delalloc_pages and %nr_async_submits from fs_info.

Although waiting on %nr_async_submits means that all bios are
submitted down to per-device schedule IO lists, it doesn't wait for
their completions, thus users still need to do fsync/sync to make sure
the data is on disk.  While with this change, it makes sure that pages
are marked with writeback bits and will be submitted asynchronously
shortly, therefore, the behavior of defrag option '-c' remains unchanged.

Signed-off-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Now that we have the combo of flushing twice, which can make sure IO
have started since the second flush will wait for page lock which
won't be unlocked unless setting page writeback and queuing ordered
extents, we don't need %async_submit_draining, %async_delalloc_pages
and %nr_async_submits to tell whether the IO has actually started.

Moreover, all the flushers in use are followed by functions that wait
for ordered extents to complete, so %nr_async_submits, which tracks
whether bio's async submit has made progress, doesn't really make
sense.

However, %async_delalloc_pages is still required by shrink_delalloc()
as that function doesn't flush twice in the normal case (just issues a
writeback with WB_REASON_FS_FREE_SPACE).

Signed-off-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We now get a harmless compile-time on 32-bit architectures:

fs/btrfs/tree-checker.c: In function 'check_extent_data_item':
fs/btrfs/tree-checker.c:189:70: error: format '%lu' expects argument of type 'long unsigned int', but argument 6 has type 'unsigned int' [-Werror=format=]

This changes the format string to use %zu instead of %lu for size_t.

Fixes: c1f6520 ("btrfs: tree-checker: Enhance output for check_extent_data_item")
Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Remove variables 'start' and 'end', which are set but never used.

Signed-off-by: Christos Gkekas <[email protected]>
Reviewed-by: Omar Sandoval <[email protected]>
Signed-off-by: David Sterba <[email protected]>

add_missing_dev() can return device pointer so that IS_ERR/PTR_ERR can
be used to check for the actual error that occurred in the function.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Liu Bo <[email protected]>
[ minor error message adjustment ]
Signed-off-by: David Sterba <[email protected]>

EIO is only for the IO failure to the device, avoid it. Use ENOENT as
that's the closest error code describing what happened.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ update changelog ]
Signed-off-by: David Sterba <[email protected]>

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>

When device is missing without the -o degraded option then its an error
so report it as an error instead of a warning.  And when -o degraded
option is provided, log the missing device as warning.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ switch error to bool ]
Signed-off-by: David Sterba <[email protected]>

We pass in a pointer in our send arg struct, this means the struct size
doesn't match with 32bit user space and 64bit kernel space.  Fix this by
adding a compat mode and doing the appropriate conversion.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ move structure to the beginning, next to receive 32bit compat ]
Signed-off-by: David Sterba <[email protected]>

The use of sector_t is not necessry, it's just for a warning.  Switch to
u64 and rename the variable and use byte units instead of 512b, ie.
dropping the >> 9 shifts.  The messages are adjusted as well.

Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We're going to remove sector_t and will use 'offset', so this patch
frees the name.

Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

The use of sector_t in the callchain of submit_extent_page is not
necessary.  Switch to u64 and rename the variable and use byte units
instead of 512b, ie.  dropping the >> 9 shifts and avoiding the
con(tro)versions of sector_t.

Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

This adds the infrastructure for turning ref verify on and off for a
mount, to be used by a later patch.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ enhnance btrfs_print_mod_info to print if ref-verify is compiled in ]
Signed-off-by: David Sterba <[email protected]>

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 <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We were having corruption issues that were tied back to problems with
the extent tree.  In order to track them down I built this tool to try
and find the culprit, which was pretty successful.  If you compile with
this tool on it will live verify every ref update that the fs makes and
make sure it is consistent and valid.  I've run this through with
xfstests and haven't gotten any false positives.  Thanks,

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ update error messages, add fixup from Dan Carpenter to handle errors
  of read_tree_block ]
Signed-off-by: David Sterba <[email protected]>

We were only doing btrfs_check_space_for_delayed_refs() if the metadata
space was full, ie we couldn't allocate chunks.  This assumes we'll be
able to allocate chunks during transaction commit, but since nothing
does a LIMIT flush during the transaction commit this won't actually
happen unless we happen to run shy of actual space.  We already take
into account a full fs in btrfs_check_space_for_delayed_refs() so just
kill this extra check to make sure we're ending the transaction when we
need to.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Simplify the error handling in __btrfs_run_delayed_refs by breaking out
the code used to return a head back to the delayed_refs tree for
processing into a helper function.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Move the extent_op cleanup for an empty head ref to a helper function to
help simplify __btrfs_run_delayed_refs.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Move this code out to a helper function to further simplivy
__btrfs_run_delayed_refs.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We only use this logic if our ref isn't a ref_head, so move it up into
the if (ref) case since we know that this is a normal ref and not a
delayed ref head.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We do a couple different cleanup operations on the ref head.  We adjust
counters, we'll free any reserved space if we didn't end up using the
ref, and we clear the pending csum bytes.  Move all these disparate
things into cleanup_ref_head and clean up the logic in
__btrfs_run_delayed_refs so that it handles the !ref case a lot cleaner,
as well as making run_one_delayed_ref() only deal with real refs and not
the ref head.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

This is just excessive information in the ref_head, and makes the code
complicated.  It is a relic from when we had the heads and the refs in
the same tree, which is no longer the case.  With this removal I've
cleaned up a bunch of the cruft around this old assumption as well.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We can get this from the ref we've passed in.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

These are useful for debugging problems where we mess with
trans->block_rsv to make sure we're not screwing something up.

Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

At few places we could use BLK_STS_OK and BLK_STS_NOSUPP.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Satoru Taekeuchi <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ dropped first hunk btrfs_endio_direct_read ]
Signed-off-by: David Sterba <[email protected]>

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 <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>

A cleanup patch, use need_full_stripe() to replace the open code.

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Qu Wenruo <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

When one of the device is missing, bbio_error() takes care of setting
the error status. And if its only IO that is pending in that stripe, it
fails to check the status of the other IO at %bbio_error before setting
the error %bi_status for the %orig_bio. Fix this by checking if
%bbio->error has exceeded the %bbio->max_errors.

Reproducer as below fdatasync error is seen intermittently.

 mount -o degraded /dev/sdc /btrfs
 dd status=none if=/dev/zero of=$(mktemp /btrfs/XXX) bs=4096 count=1 conv=fdatasync

 dd: fdatasync failed for ‘/btrfs/LSe’: Input/output error

 The reason for the intermittences of the problem is because
 the following conditions have to be met, which depends on timing:
 In btrfs_map_bio()
  - the RAID1 the missing device has to be at %dev_nr = 1
 In bbio_error()
  . before bbio_error() is called the bio of the not-missing
    device at %dev_nr = 0 must be completed so that the below
    condition is true
     if (atomic_dec_and_test(&bbio->stripes_pending)) {

Signed-off-by: Anand Jain <[email protected]>
Reviewed-by: Liu Bo <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Fix missing change from commit f8f84b2
("btrfs: index check-integrity state hash by a dev_t").

Function btrfsic_dev_state_hashtable_lookup uses dev_t to generate hashval
when look in up a btrfsic_dev_state in hash table. So when we add a
btrfsic_dev_state into the hash table, it should also use dev_t.

Reproducer of this bug:
Use MOUNT_OPTIONS="-o check_int" when running xfstest, device can not be
mounted successfully. So xfstest can not run.

Signed-off-by: Gu JinXiang <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Currently btrfs' code uses a mix of opencoded sizes and defines from sizes.h.
Let's unifiy the code base to always use the symbolic constants. No functional
changes

Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Preliminary support for setting compression level for zlib, the
following works:

$ mount -o compess=zlib                 # default
$ mount -o compess=zlib0                # same
$ mount -o compess=zlib9                # level 9, slower sync, less data
$ mount -o compess=zlib1                # level 1, faster sync, more data
$ mount -o remount,compress=zlib3	# level set by remount

The compress-force works the same as compress'.  The level is visible in
the same format in /proc/mounts. Level set via file property does not
work yet.

Required patch: "btrfs: prepare for extensions in compression options"

Signed-off-by: David Sterba <[email protected]>

This is bikeshedding, but it seems people are drastically more likely to
understand "zlib:9" as compression level rather than an algorithm
version compared to "zlib9".

Based on feedback on the mailinglist, the ":9" will be the only accepted
syntax. The level must be a single digit. Unrecognized format will
result to the default, for forward compatibility in a similar way the
compression algorithm specifier was relaxed in commit
a7164fa ("btrfs: prepare for extensions in compression
options").

Signed-off-by: Adam Borowski <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ tighten the accepted format ]
Signed-off-by: David Sterba <[email protected]>

That was only an extra check to tackle a few bugs around this area, now
its safe to remove it.  Replace it by an ASSERT.

Signed-off-by: Anand Jain <[email protected]>
Signed-off-by: David Sterba <[email protected]>

This code was first introduced in 31db9f7 ("Btrfs: introduce
BTRFS_IOC_SEND for btrfs send/receive") and it was not functional, then
it got slightly refactored in e938c8a ("Btrfs: code cleanups for
send/receive"), alas it was still dead. So let's remove it for good!

Signed-off-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

…efs for uncompressed extents

The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address).  These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).

When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset.  This prevents LOGICAL_INO from returning
references to more than a single block.

To find the set of extent references to an uncompressed extent from [a, b),
userspace has to run a loop like this pseudocode:

	for (i = a; i < b; ++i)
		extent_ref_set += LOGICAL_INO(i);

At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.

When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent.  This removes
the need for the loop, since we get all the extent refs in one call.

Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.

There is no functional change in this patch.  The new flag is always
false.

Signed-off-by: Zygo Blaxell <[email protected]>
Reviewed-by: David Sterba <[email protected]>
[ minor coding style fixes ]
Signed-off-by: David Sterba <[email protected]>

Now that check_extent_in_eb()'s extent offset filter can be turned off,
we need a way to do it from userspace.

Add a 'flags' field to the btrfs_logical_ino_args structure to disable
extent offset filtering, taking the place of one of the existing
reserved[] fields.

Previous versions of LOGICAL_INO neglected to check whether any of the
reserved fields have non-zero values.  Assigning meaning to those fields
now may change the behavior of existing programs that left these fields
uninitialized.  The lack of a zero check also means that new programs
have no way to know whether the kernel is honoring the flags field.

To avoid these problems, define a new ioctl LOGICAL_INO_V2.  We can
use the same argument layout as LOGICAL_INO, but shorten the reserved[]
array by one element and turn it into the 'flags' field.  The V2 ioctl
explicitly checks that reserved fields and unsupported flag bits are zero
so that userspace can negotiate future feature bits as they are defined.

Since the memory layouts of the two ioctls' arguments are compatible,
there is no need for a separate function for logical_to_ino_v2 (contrast
with tree_search_v2 vs tree_search where the layout and code are quite
different).  A version parameter and an 'if' statement will suffice.

Now that we have a flags field in logical_ino_args, add a flag
BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET to get the behavior we want,
and pass it down the stack to iterate_inodes_from_logical.

Motivation and background, copied from the patchset cover letter:

Suppose we have a file with one extent:

    root@tester:~# zcat /usr/share/doc/cpio/changelog.gz > /test/a
    root@tester:~# sync

Split the extent by overwriting it in the middle:

    root@tester:~# cat /dev/urandom | dd bs=4k seek=2 skip=2 count=1 conv=notrunc of=/test/a

We should now have 3 extent refs to 2 extents, with one block unreachable.
The extent tree looks like:

    root@tester:~# btrfs-debug-tree /dev/vdc -t 2
    [...]
            item 9 key (1103101952 EXTENT_ITEM 73728) itemoff 15942 itemsize 53
                    extent refs 2 gen 29 flags DATA
                    extent data backref root 5 objectid 261 offset 0 count 2
    [...]
            item 11 key (1103175680 EXTENT_ITEM 4096) itemoff 15865 itemsize 53
                    extent refs 1 gen 30 flags DATA
                    extent data backref root 5 objectid 261 offset 8192 count 1
    [...]

and the ref tree looks like:

    root@tester:~# btrfs-debug-tree /dev/vdc -t 5
    [...]
            item 6 key (261 EXTENT_DATA 0) itemoff 15825 itemsize 53
                    extent data disk byte 1103101952 nr 73728
                    extent data offset 0 nr 8192 ram 73728
                    extent compression(none)
            item 7 key (261 EXTENT_DATA 8192) itemoff 15772 itemsize 53
                    extent data disk byte 1103175680 nr 4096
                    extent data offset 0 nr 4096 ram 4096
                    extent compression(none)
            item 8 key (261 EXTENT_DATA 12288) itemoff 15719 itemsize 53
                    extent data disk byte 1103101952 nr 73728
                    extent data offset 12288 nr 61440 ram 73728
                    extent compression(none)
    [...]

There are two references to the same extent with different, non-overlapping
byte offsets:

    [------------------72K extent at 1103101952----------------------]
    [--8K----------------|--4K unreachable----|--60K-----------------]
    ^                                         ^
    |                                         |
    [--8K ref offset 0--][--4K ref offset 0--][--60K ref offset 12K--]
                         |
                         v
                         [-----4K extent-----] at 1103175680

We want to find all of the references to extent bytenr 1103101952.

Without the patch (and without running btrfs-debug-tree), we have to
do it with 18 LOGICAL_INO calls:

    root@tester:~# btrfs ins log 1103101952 -P /test/
    Using LOGICAL_INO
    inode 261 offset 0 root 5

    root@tester:~# for x in $(seq 0 17); do btrfs ins log $((1103101952 + x * 4096)) -P /test/; done 2>&1 | grep inode
    inode 261 offset 0 root 5
    inode 261 offset 4096 root 5   <- same extent ref as offset 0
                                   (offset 8192 returns empty set, not reachable)
    inode 261 offset 12288 root 5
    inode 261 offset 16384 root 5  \
    inode 261 offset 20480 root 5  |
    inode 261 offset 24576 root 5  |
    inode 261 offset 28672 root 5  |
    inode 261 offset 32768 root 5  |
    inode 261 offset 36864 root 5  \
    inode 261 offset 40960 root 5   > all the same extent ref as offset 12288.
    inode 261 offset 45056 root 5  /  More processing required in userspace
    inode 261 offset 49152 root 5  |  to figure out these are all duplicates.
    inode 261 offset 53248 root 5  |
    inode 261 offset 57344 root 5  |
    inode 261 offset 61440 root 5  |
    inode 261 offset 65536 root 5  |
    inode 261 offset 69632 root 5  /

In the worst case the extents are 128MB long, and we have to do 32768
iterations of the loop to find one 4K extent ref.

With the patch, we just use one call to map all refs to the extent at once:
    root@tester:~# btrfs ins log 1103101952 -P /test/
    Using LOGICAL_INO_V2
    inode 261 offset 0 root 5
    inode 261 offset 12288 root 5

The TREE_SEARCH ioctl allows userspace to retrieve the offset and
extent bytenr fields easily once the root, inode and offset are known.
This is sufficient information to build a complete map of the extent
and all of its references.  Userspace can use this information to make
better choices to dedup or defrag.

Signed-off-by: Zygo Blaxell <[email protected]>
Reviewed-by: Hans van Kranenburg <[email protected]>
Tested-by: Hans van Kranenburg <[email protected]>
[ copy background and motivation from cover letter ]
Signed-off-by: David Sterba <[email protected]>

Build-server workloads have hundreds of references per file after dedup.
Multiply by a few snapshots and we quickly exhaust the limit of 2730
references per extent that can fit into a 64K buffer.

Raise the limit to 16M to be consistent with other btrfs ioctls
(e.g. TREE_SEARCH_V2, FILE_EXTENT_SAME).

To minimize surprising userspace behavior, apply this change only to
the LOGICAL_INO_V2 ioctl.

Signed-off-by: Zygo Blaxell <[email protected]>
Reviewed-by: Hans van Kranenburg <[email protected]>
Tested-by: Hans van Kranenburg <[email protected]>
Signed-off-by: David Sterba <[email protected]>

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 <[email protected]>
Signed-off-by: David Sterba <[email protected]>

This is handy for tracing problems with modifying the outstanding
extents counters.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

The way we handle delalloc metadata reservations has gotten
progressively more complicated over the years.  There is so much cruft
and weirdness around keeping the reserved count and outstanding counters
consistent and handling the error cases that it's impossible to
understand.

Fix this by making the delalloc block rsv per-inode.  This way we can
calculate the actual size of the outstanding metadata reservations every
time we make a change, and then reserve the delta based on that amount.
This greatly simplifies the code everywhere, and makes the error
handling in btrfs_delalloc_reserve_metadata far less terrifying.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Make it more consistent, we want the inserted ref to be compared against
what's already in there.  This will make the order go from lowest seq ->
highest seq, which will make us more likely to make forward progress if
there's a seqlock currently held.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Instead of open-coding the delayed ref comparisons, add a helper to do
the comparisons generically and use that everywhere.  We compare
sequence numbers last for following patches.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

If we get a significant amount of delayed refs for a single block (think
modifying multiple snapshots) we can end up spending an ungodly amount
of time looping through all of the entries trying to see if they can be
merged.  This is because we only add them to a list, so we have O(2n)
for every ref head.  This doesn't make any sense as we likely have refs
for different roots, and so they cannot be merged.  Tracking in a tree
will allow us to break as soon as we hit an entry that doesn't match,
making our worst case O(n).

With this we can also merge entries more easily.  Before we had to hope
that matching refs were on the ends of our list, but with the tree we
can search down to exact matches and merge them at insert time.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

We're holding the sb_start_intwrite lock at this point, and doing async
filemap_flush of the inodes will result in a deadlock if we freeze the
fs during this operation.  This is because we could do a
btrfs_join_transaction() in the thread we are waiting on which would
block at sb_start_intwrite, and thus deadlock.  Using
writeback_inodes_sb() side steps the problem by not introducing all of
these extra locking dependencies.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Since we do a delalloc reserve in btrfs_truncate_block we can deadlock
with freeze.  If somebody else is trying to allocate metadata for this
inode and it gets stuck in start_delalloc_inodes because of freeze we
will deadlock.  Be safe and move this outside of a trans handle.  This
also has a side-effect of making sure that we're not leaving stale data
behind in the other_encoding or encryption case.  Not an issue now since
nobody uses it, but it would be a problem in the future.

Signed-off-by: Josef Bacik <[email protected]>
Signed-off-by: David Sterba <[email protected]>