linux.git/fs/btrfs/export.c, branch v5.7

btrfs: kill the subvol_srcu

2020-03-23T16:02:00+00:00

Now that we have proper root ref counting everywhere we can kill the
subvol_srcu.

* removal of fs_info::subvol_srcu reduces size of fs_info by 1176 bytes

* the refcount_t used for the references checks for accidental 0->1
  in cases where the root lifetime would not be properly protected

* there's a leak detector for roots to catch unfreed roots at umount
  time

* SRCU served us well over the years but is was not a proper
  synchronization mechanism for some cases

Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
[ update changelog ]
Signed-off-by: David Sterba

btrfs: export helpers for subvolume name/id resolution

2020-03-23T16:01:42+00:00

The functions will be used outside of export.c and super.c to allow
resolving subvolume name from a given id, eg. for subvolume deletion by
id ioctl.

Signed-off-by: Marcos Paulo de Souza 
Reviewed-by: David Sterba 
[ split from the next patch ]
Signed-off-by: David Sterba

btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root

2020-03-23T16:01:33+00:00

We are now using these for all roots, rename them to btrfs_put_root()
and btrfs_grab_root();

Reviewed-by: Nikolay Borisov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root

2020-03-23T16:01:32+00:00

Now that all callers of btrfs_get_fs_root are subsequently calling
btrfs_grab_fs_root and handling dropping the ref when they are done
appropriately, go ahead and push btrfs_grab_fs_root up into
btrfs_get_fs_root.

Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: hold a root ref in btrfs_get_dentry

2020-03-23T16:01:27+00:00

Looking up the inode we need to search the root, make sure we hold a
reference on that root while we're doing the lookup.

Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: open code btrfs_read_fs_root_no_name

2020-03-23T16:01:26+00:00

All this does is call btrfs_get_fs_root() with check_ref == true.  Just
use btrfs_get_fs_root() so we don't have a bunch of different helpers
that do the same thing.

Reviewed-by: Nikolay Borisov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: drop unused parameter is_new from btrfs_iget

2019-11-18T11:46:52+00:00

The parameter is now always set to NULL and could be dropped. The last
user was get_default_root but that got reworked in 05dbe6837b60 ("Btrfs:
unify subvol= and subvolid= mounting") and the parameter became unused.

Reviewed-by: Anand Jain 
Signed-off-by: David Sterba

btrfs: Remove 'objectid' member from struct btrfs_root

2018-10-15T15:23:25+00:00

There are two members in struct btrfs_root which indicate root's
objectid: objectid and root_key.objectid.

They are both set to the same value in __setup_root():

  static void __setup_root(struct btrfs_root *root,
                           struct btrfs_fs_info *fs_info,
                           u64 objectid)
  {
    ...
    root->objectid = objectid;
    ...
    root->root_key.objectid = objecitd;
    ...
  }

and not changed to other value after initialization.

grep in btrfs directory shows both are used in many places:
  $ grep -rI "root->root_key.objectid" | wc -l
  133
  $ grep -rI "root->objectid" | wc -l
  55
 (4.17, inc. some noise)

It is confusing to have two similar variable names and it seems
that there is no rule about which should be used in a certain case.

Since ->root_key itself is needed for tree reloc tree, let's remove
'objecitd' member and unify code to use ->root_key.objectid in all places.

Signed-off-by: Misono Tomohiro 
Reviewed-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba

btrfs: Cleanup existing name_len checks

2018-01-22T15:08:12+00:00

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 
Reviewed-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba