[BUG]
fm_mapped_extents is not correct when fm_extent_count is 0
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/btrfs/file:
   EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
     0: [0..127]:        25088..25215       128   0x1

When user space wants to get the number of file extents,
set fm_extent_count to 0 to run fiemap and then read fm_mapped_extents.

In the above example, fiemap will return with fm_mapped_extents set to 4,
but it should be 1 since there's only one entry in the output.

[REASON]
The problem seems to be that disko is only set if
fieinfo->fi_extents_max is set. And this member is initialized, in the
generic ioctl_fiemap function, to the value of used-passed
fm_extent_count. So when the user passes 0 then fi_extent_max is also
set to zero and this causes btrfs to not initialize disko at all.
Eventually this leads emit_fiemap_extent being called with a bogus
'phys' argument preventing proper fiemap entries merging.

[FIX]
Move the disko initialization earlier in extent_fiemap making it
independent of user-passed arguments, allowing emit_fiemap_extent to
properly handle consecutive extent entries.
Signed-off-by: NRobbie Ko <robbieko@synology.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It can be directly referenced from the passed address_space so do that.
No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This function is called only from btrfs_readpage and is already passed
the mapping. Simplify its signature by moving the code obtaining
reference to the extent tree in the function. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It's not used in the function so just remove it. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This function already gets the page from which the two extent trees
are referenced. Simplify its signature by moving the code getting the
trees inside the function. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

le_bitmap_set() is only used by free-space-tree, so move it there and
make it static. le_bitmap_clear() is not used, so remove it.
Signed-off-by: NHoward McLauchlan <hmclauchlan@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root.  Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.

[willy@infradead.org: fix nds32, fs/dax.c]
  Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The missing error handling in add_extent_changeset was hidden, so make
it at least visible in the callers.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NDavid Sterba <dsterba@suse.com>

The merge call was factored out to a separate helper but it's a trivial
one and arguably we can opencode it and cache the value.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The value of page_end is only stored to end, no other use.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass a valid pointer so we can drop the redundant checks.
The call to submit_one_bio never happend and can be removed.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The __cold functions are placed to a special section, as they're
expected to be called rarely. This could help i-cache prefetches or help
compiler to decide which branches are more/less likely to be taken
without any other annotations needed.

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

- printf wrappers, error messages
- exit helpers
Signed-off-by: NDavid Sterba <dsterba@suse.com>

extent_buffer_uptodate() is a trivial wrapper around test_bit() and
nothing else. So make it static and inline, save on code space and call
indirection.

Before:
   text	   data	    bss	    dec	    hex	filename
1131257	  82898	  18992	1233147	 12d0fb	fs/btrfs/btrfs.ko

After:
   text	   data	    bss	    dec	    hex	filename
1131090	  82898	  18992	1232980	 12d054	fs/btrfs/btrfs.ko
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This prints out eb->bflags since it contains some useful information,
e.g. whether eb is dirty.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass either GFP_NOFS or GFP_KERNEL now, so we can sink the
parameter to the function, though we lose some of the slightly better
semantics of GFP_KERNEL in some places, it's worth cleaning up the
callchains.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There's only one instance where we pass different gfp mask to
unlock_extent_cached. Add a separate helper for that and then we can
drop the gfp parameter from unlock_extent_cached.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The bio is never referenced after it has been submitted so there is no
point in getting an extra reference.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Functions called from extent_write_cache_pages used void* as generic
callback data, but all of them convert it to extent_page_data, or use it
directly.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The function extent_write_cache_pages is modelled after
write_cache_pages which is a generic interface and the writepage
parameter makes sense there. In btrfs we know exactly which callback
we're going to use, so we can pass it directly.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass the same value flush_write_bio.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

flush_epd_write_bio is same as flush_write_bio, no point having two such
functions. Merge them to flush_write_bio. The 'noinline' attribute is
removed as it does not have any meaning.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The tree argument passed to extent_write_full_page is referenced from
the page being passed to the same function. Since we already have
enough information to get the reference, remove the function parameter.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This function is called only from submit_compressed_extents and the
io tree being passed is always that of the inode. But we are also
passing the inode, so just move getting the io tree pointer in
extent_write_locked_range to simplify the signature.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Currently device state is being managed by each individual int
variable such as struct btrfs_device::writeable. Instead of that
declare device state BTRFS_DEV_STATE_WRITEABLE and use the
bit operations.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
[ whitespace adjustments ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit 9036c102 ("Btrfs: update hole handling v2") added the
FLAG_VACANCY to denote holes, however there was already a consistent way
of flagging extents which represent hole - ->block_start =
EXTENT_MAP_HOLE. And also the only place where this flag is checked is
in the fiemap code, but the block_start value is also checked and every
other place in the filesystem detects holes by using block_start
value's. So remove the extra flag. This survived a full xfstest run.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass btree_get_extent, which needs to be exported.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass btrfs_get_extent.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass btrfs_get_extent.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There's only one caller that passes btrfs_get_extent.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass btrfs_get_extent_fiemap and get_extent_skip_holes
itself is used only as a fiemap helper.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers pass btrfs_get_extent_fiemap and we don't expect anything
else in the context of extent_fiemap.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Previous patches cleaned up all places where
extent_page_data::get_extent was set and it was btrfs_get_extent all the
time, so we can simply call that instead.

This also reduces size of extent_page_data by 8 bytes which has positive
effect on stack consumption on various functions on the write out path.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There's only one caller.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There's only one caller.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There's only one caller.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers use GFP_NOFS, we don't have to pass it as an argument. The
built-in tests pass GFP_KERNEL, but they run only at module load time
and NOFS works there as well.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Use __clear_extent_bit directly in case we want to pass unknown
gfp flags. Otherwise all clear_extent_bit callers use GFP_NOFS, so we
can sink them to the function and reduce argument count, at the cost
that __clear_extent_bit has to be exported.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The following callpath is always invoked with mirror_num set to 0, so
let's remove it as an argument and directly pass 0 to __do_redpage. No
functional change.

extent_readpages
  __extent_readpages
    __do_contiguous_readpages
      __do_readpage
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>