exfat: fs: add CONFIG_BUFFER_HEAD

Add a new config option that controls building the buffer_head code, and
select it from all file systems and stacking drivers that need it.

For the block device nodes and alternative iomap based buffered I/O path
is provided when buffer_head support is not enabled, and iomap needs a
a small tweak to define the IOMAP_F_BUFFER_HEAD flag to 0 to not call
into the buffer_head code when it doesn't exist.

Otherwise this is just Kconfig and ifdef changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230801172201.1923299-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This commit is contained in:
Christoph Hellwig 2023-11-02 22:52:14 +09:00 committed by Namjae Jeon
parent 950e271397
commit 98f3631506

View File

@ -2,6 +2,7 @@
config EXFAT_FS
tristate "exFAT filesystem support"
select BUFFER_HEAD
select NLS
select LEGACY_DIRECT_IO
help