This is in preparation to move a section of code in __btrfs_open_devices()
into a new function so that it can be reused. As we set seeding if any of
the device is having SB flag BTRFS_SUPER_FLAG_SEEDING, so do it in the
device list loop itself. No functional changes.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

With gcc-4.1.2:

    fs/btrfs/ref-verify.c: In function ‘btrfs_build_ref_tree’:
    fs/btrfs/ref-verify.c:1017: warning: ‘root’ is used uninitialized in this function

The variable is indeed passed uninitialized, but it is never used by the
callee.  However, not all versions of gcc are smart enough to notice.

Hence remove the unused parameter from walk_up_tree() to silence the
compiler warning.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David Sterba <dsterba@suse.com>

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

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

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

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

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

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

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

Since tree-checker has verified leaf when reading from disk, we don't
need the existing verify_dir_item() or btrfs_is_name_len_valid() checks.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Add checker for dir item, for key types DIR_ITEM, DIR_INDEX and
XATTR_ITEM.

This checker does comprehensive checks for:

1) dir_item header and its data size
   Against item boundary and maximum name/xattr length.
   This part is mostly the same as old verify_dir_item().

2) dir_type
   Against maximum file types, and against key type.
   Since XATTR key should only have FT_XATTR dir item, and normal dir
   item type should not have XATTR key.

   The check between key->type and dir_type is newly introduced by this
   patch.

3) name hash
   For XATTR and DIR_ITEM key, key->offset is name hash (crc32c).
   Check the hash of the name against the key to ensure it's correct.

   The name hash check is only found in btrfs-progs before this patch.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This callback is called directly from VFS, no locks are held at the
allocation time.
Signed-off-by: David Sterba <dsterba@suse.com>

There's only one callsite with GFP_NOFS.
Signed-off-by: David 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: David 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: David Sterba <dsterba@suse.com>

We take the fs_devices::device_list_mutex mutex in write_all_supers
which will prevent any add/del changes to the device list. Therefore we
don't need to use the RCU variant list_for_each_entry_rcu in any of the
called functions.
Signed-off-by: David Sterba <dsterba@suse.com>

We don't need to use the mutex as we do not modify the devices nor the
list itself and just read information about device counts.
Move copying fsid out of the protected section, not applicable to RCU
same as the rest of the retrieved information.
Signed-off-by: David Sterba <dsterba@suse.com>

We don't need to use the mutex as we do not modify the devices nor the
list itself and just read some information:

does not change during device lifetime:
- devid
- uuid
- name (ie. the path)

may change in parallel to the ioctl call, but can lead only to reporting
inacurracy:
- bytes_used
- total_bytes
Signed-off-by: David Sterba <dsterba@suse.com>

Split the conditions a bit.
Signed-off-by: David Sterba <dsterba@suse.com>

Overview of the main locks protecting various device-related structures.
Signed-off-by: David Sterba <dsterba@suse.com>

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

A helper to free a device and all it's dynamically allocated members,
like the rcu_string name or flush_bio. This is going to replace all
open coded places.
Signed-off-by: David Sterba <dsterba@suse.com>

Make it clear that it is an RCU helper, we want to use the name
free_device for a wrapper freeing all device members.
Signed-off-by: David Sterba <dsterba@suse.com>

These rules have been hidden in several if-else and are not
straightforward to follow, for example, dio submit hook's nocsum case
has a bug , i.e. doing async submit instead of sync submit, which has
been fixed recently.

This is documenting the rules for reference.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

After commit 996478ca ("btrfs: change how we decide to commit
transactions during flushing") there is no need to hold the delayed_rsv
during the percpu_counter_compare call since we get the byte's snapshot
earlier. So hold the lock only while reading delayed_rsv.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Adding __init macro gives kernel a hint that this function is only used
during the initialization phase and its memory resources can be freed up
after.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Function btrfs_add_device() is adding the device item so rename to
reflect that in the function. Similarly we have btrfs_rm_dev_item().
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

btrfs_create_tree() will unconditionally generate UUID for any root.
So for quota tree and data reloc tree created by kernel, they will have
unique UUIDs.

However UUID in root item is only referred by UUID tree, which only
records UUID for fs trees.  This makes unique UUIDs for quota/data reloc
tree meaningless.

Leave the UUID as zero for non-fs tree, making btrfs-debug-tree output
less confusing.
Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

A cleanup patch no functional change, we hold volume_mutex before
calling btrfs_rm_device, so move it into the function itself.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Right before we go into this loop locked_end is set to alloc_end - 1 and
is being used in nearby functions, no need to have exceptions. This just
makes the code consistent, no functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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

It was introduced because btrfs used to do blkdev_put in a deferred
work, now that btrfs has blkdev_put in place, this rcu_barrier can be
removed.

modprobe -r btrfs will do btrfs_cleanup_fs_uuids(), where it cleanup
every %fs_devices on the list, but when we do btrfs_close_devices(), we
have replaced the devices on the list with dummy ones which only have
the same name and uuid, so modprobe -r btrfs will free those instead of
what we were using, this change won't cause a problem for it.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ copied 2nd paragraph from mailinglist discussion ]
Signed-off-by: David Sterba <dsterba@suse.com>

btrfs_balance_delayed_items is the sole caller of
btrfs_wq_run_delayed_node and already includes one of the checks whether
the delayed inodes should be run. On the other hand
btrfs_wq_run_delayed_node duplicates that check and performs an
additional one for wq congestion.

Let's remove the duplicate check and move the congestion one in
btrfs_balance_delayed_items, leaving btrfs_wq_run_delayed_node to only
care about setting up the wq run. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently btrfs_async_run_delayed_root's implementation uses 3 goto
labels to mimic the functionality of a simple do {} while loop. Refactor
the function to use a do {} while construct, making intention clear and
code easier to follow. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David 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: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

It's sole callsite was removed in a previous patch so just nuke it for good.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>