Commit bee9182d authored by Oleg Nesterov's avatar Oleg Nesterov
Browse files

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: default avatarOleg Nesterov <oleg@redhat.com>
Reviewed-by: default avatarJan Kara <jack@suse.com>
parent 45e38cff

fs/btrfs/transaction.c

+2 −6
Original line number Diff line number Diff line
@@ -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);

fs/xfs/xfs_aops.c

+2 −4
Original line number Diff line number Diff line
@@ -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);

}

include/linux/fs.h

+5 −0
Original line number Diff line number Diff line
@@ -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

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