zonefs: use iomap for synchronous direct writes

Remove the function zonefs_file_dio_append() that is used to manually
issue REQ_OP_ZONE_APPEND BIOs for processing synchronous direct writes
and use iomap instead.

To preserve the use of zone append operations for synchronous writes,
different struct iomap_dio_ops are defined. For synchronous direct
writes using zone append, zonefs_zone_append_dio_ops is introduced.
The submit_bio operation of this structure is defined as the function
zonefs_file_zone_append_dio_submit_io() which is used to change the BIO
opreation for synchronous direct IO writes to REQ_OP_ZONE_APPEND.

In order to preserve the write location check on completion of zone
append BIOs, the end_io operation is also defined using the function
zonefs_file_zone_append_dio_bio_end_io(). This check now relies on the
zonefs_zone_append_bio structure, allocated together with zone append
BIOs with a dedicated BIO set. This structure include the target inode
of a zone append BIO as well as the target append offset location for
the zone append operation. This is used to perform a check against
bio->bi_iter.bi_sector when the BIO completes, without needing to use
the zone information z_wpoffset field, thus removing the need for
taking the inode truncate mutex.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c
index 23b8b299c64e..56c00111966a 100644
--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -1412,10 +1412,14 @@ static int __init zonefs_init(void)
 
 	BUILD_BUG_ON(sizeof(struct zonefs_super) != ZONEFS_SUPER_SIZE);
 
-	ret = zonefs_init_inodecache();
+	ret = zonefs_file_bioset_init();
 	if (ret)
 		return ret;
 
+	ret = zonefs_init_inodecache();
+	if (ret)
+		goto destroy_bioset;
+
 	ret = zonefs_sysfs_init();
 	if (ret)
 		goto destroy_inodecache;
@@ -1430,6 +1434,8 @@ sysfs_exit:
 	zonefs_sysfs_exit();
 destroy_inodecache:
 	zonefs_destroy_inodecache();
+destroy_bioset:
+	zonefs_file_bioset_exit();
 
 	return ret;
 }
@@ -1439,6 +1445,7 @@ static void __exit zonefs_exit(void)
 	unregister_filesystem(&zonefs_type);
 	zonefs_sysfs_exit();
 	zonefs_destroy_inodecache();
+	zonefs_file_bioset_exit();
 }
 
 MODULE_AUTHOR("Damien Le Moal");