From: Taotao Chen <chentaotao@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> --- fs/ext4/inode.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 7ff7009f9799..3a82b52565cc 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1269,6 +1269,9 @@ static int ext4_write_begin(struct kiocb *iocb, struct address_space *mapping, if (unlikely(ret)) return ret; + if (iocb->ki_flags & IOCB_DONTCACHE) + fgp |= FGP_DONTCACHE; + trace_ext4_write_begin(inode, pos, len); /* * Reserve one block more for addition to orphan list in case @@ -3066,6 +3069,9 @@ static int ext4_da_write_begin(struct kiocb *iocb, struct address_space *mapping return 0; } + if (iocb->ki_flags & IOCB_DONTCACHE) + fgp |= FGP_DONTCACHE; + retry: fgp |= fgf_set_order(len); folio = __filemap_get_folio(mapping, index, fgp, -- 2.34.1
