xfs: Convert to new freezing code

Generic code now blocks all writers from standard write paths. So we add
blocking of all writers coming from ioctl (we get a protection of ioctl against
racing remount read-only as a bonus) and convert xfs_file_aio_write() to a
non-racy freeze protection. We also keep freeze protection on transaction
start to block internal filesystem writes such as removal of preallocated
blocks.

CC: Ben Myers <bpm@sgi.com>
CC: Alex Elder <elder@kernel.org>
CC: xfs@oss.sgi.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index 7c37b533aa8e..19c174282878 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -179,6 +179,8 @@ struct xfs_log_item_desc {
 #define XFS_TRANS_SYNC          0x08    /* make commit synchronous */
 #define XFS_TRANS_DQ_DIRTY      0x10    /* at least one dquot in trx dirty */
 #define XFS_TRANS_RESERVE       0x20    /* OK to use reserved data blocks */
+#define XFS_TRANS_FREEZE_PROT   0x40    /* Transaction has elevated writer
+                                           count in superblock */
 
 /*
  * Values for call flags parameter.