This adds support for the AOP_FLAGS_BUF_WASYNC flag to the fs layer. If
a page that is required for writing is not in the page cache, it returns
EAGAIN instead of ENOMEM.
Signed-off-by: Stefan Roesch <shr@xxxxxx>
---
fs/buffer.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index ae588ae4b1c1..58331ef214b9 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2062,6 +2062,7 @@ int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
*wait_bh++=bh;
}
}
+
/*
* If we issued read requests - let them complete.
*/
@@ -2141,8 +2142,11 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
gfp = GFP_ATOMIC | __GFP_NOWARN;
page = grab_cache_page_write_begin(mapping, index, flags);
- if (!page)
+ if (!page) {
+ if (no_wait)
+ return -EAGAIN;
return -ENOMEM;
+ }
status = __block_write_begin_int(page_folio(page), pos, len, get_block, NULL, gfp);
if (unlikely(status)) {
--
2.30.2
