introduce __sb_writers_{acquired,release}() helpers

Preparation to hide the sb->s_writers internals from xfs and btrfs.
Add 2 trivial define's they can use rather than play with ->s_writers
directly. No changes in btrfs/transaction.o and xfs/xfs_aops.o.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>

diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index f5021fcb154e3bfa3773a79d94ee4750be48ca0d..a8ab8f5ef38e1954244b7be4651694569b469238 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1638,9 +1638,7 @@ static void do_async_commit(struct work_struct *work)
         * Tell lockdep about it.
         */
        if (ac->newtrans->type & __TRANS_FREEZABLE)
-               rwsem_acquire_read(
-                    &ac->root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
-                    0, 1, _THIS_IP_);
+               __sb_writers_acquired(ac->root->fs_info->sb, SB_FREEZE_FS);
 
        current->journal_info = ac->newtrans;
 
@@ -1679,9 +1677,7 @@ int btrfs_commit_transaction_async(struct btrfs_trans_handle *trans,
         * async commit thread will be the one to unlock it.
         */
        if (ac->newtrans->type & __TRANS_FREEZABLE)
-               rwsem_release(
-                       &root->fs_info->sb->s_writers.lock_map[SB_FREEZE_FS-1],
-                       1, _THIS_IP_);
+               __sb_writers_release(root->fs_info->sb, SB_FREEZE_FS);
 
        schedule_work(&ac->work);
 

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 3859f5e27a4dc209be159659f33d777931d31cea..9bbb3507376a7503ece35508c765e6929fb9fbd6 100644 (file)
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -119,8 +119,7 @@ xfs_setfilesize_trans_alloc(
         * We may pass freeze protection with a transaction.  So tell lockdep
         * we released it.
         */
-       rwsem_release(&ioend->io_inode->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
-                     1, _THIS_IP_);
+       __sb_writers_release(ioend->io_inode->i_sb, SB_FREEZE_FS);
        /*
         * We hand off the transaction to the completion thread now, so
         * clear the flag here.
@@ -171,8 +170,7 @@ xfs_setfilesize_ioend(
         * Similarly for freeze protection.
         */
        current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
-       rwsem_acquire_read(&VFS_I(ip)->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
-                          0, 1, _THIS_IP_);
+       __sb_writers_acquired(VFS_I(ip)->i_sb, SB_FREEZE_FS);
 
        return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
 }

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 84b783f277f761a0ef7b940bd1fbab37db60567e..acb7cad84edd2550cbfad31c860b5cb2a72c2377 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1391,6 +1391,11 @@ extern struct timespec current_fs_time(struct super_block *sb);
 void __sb_end_write(struct super_block *sb, int level);
 int __sb_start_write(struct super_block *sb, int level, bool wait);
 
+#define __sb_writers_acquired(sb, lev) \
+       rwsem_acquire_read(&(sb)->s_writers.lock_map[(lev)-1], 0, 1, _THIS_IP_)
+#define __sb_writers_release(sb, lev)  \
+       rwsem_release(&(sb)->s_writers.lock_map[(lev)-1], 1, _THIS_IP_)
+
 /**
  * sb_end_write - drop write access to a superblock
  * @sb: the super we wrote to