[PATCH v2 4/5] ext4: handle IOCB_DONTCACHE in buffered write path

[Theodore Ts'o]

On Tue, Jun 24, 2025 at 12:12:09PM +0000, 陈涛涛 Taotao Chen wrote:
> From: Taotao Chen <chentaotao at didiglobal.com>
> 
> Add support for the IOCB_DONTCACHE flag in ext4_write_begin() and
> ext4_da_write_begin(). When set in the kiocb, the FGP_DONTCACHE bit
> is passed to the page cache lookup, preventing written pages from
> being retained in the cache.
> 
> Only the handling logic is implemented here; the behavior remains
> inactive until ext4 advertises support via FOP_DONTCACHE.
> 
> This change relies on prior patches that refactor the write_begin
> interface to use struct kiocb and introduce DONTCACHE handling in ext4.
> 
> Part of a series refactoring address_space_operations write_begin and
> write_end callbacks to use struct kiocb for passing write context and
> flags.
> 
> Signed-off-by: Taotao Chen <chentaotao at didiglobal.com>

Acked-by: Theodore Ts'o <tytso at mit.edu>