netfs: zero the tail of a short DIO/unbuffered readgrafted

The buffered read collector zero-fills the tail of a short read that
stops below the inode's i_size (netfs_clear_unread()), so a read that
races an extending write still returns the expected number of bytes.
The non-buffered collector path does no such thing: it just records
how much was transferred.

Add the same zero-fill for the non-buffered case, gated on
NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short
result from it is known to be safe to treat as a hole, as opposed to
NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of
the file and should be reported short as-is. Only CLEAR_TAIL should
zero-fill here; a real EOF must stay a real short read.

No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest,
so this is inert on its own -- a following change teaches cifs to set
it in the one case that needs it.

Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Shyam Prasad N <sprasad@microsoft.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Bharath SM <bharathsm@microsoft.com>
Cc: stable@vger.kernel.org

1 files changed, 33 insertions, 0 deletions

diff --git a/include/dt-bindings/clock/berlin2q.h b/include/dt-bindings/clock/berlin2q.h
new file mode 100644
index 000000000..44b4ac382
--- /dev/null
+++ b/include/dt-bindings/clock/berlin2q.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Berlin2 BG2Q clock tree IDs
+ */
+
+#define CLKID_SYS		0
+#define CLKID_DRMFIGO		1
+#define CLKID_CFG		2
+#define CLKID_GFX2D		3
+#define CLKID_ZSP		4
+#define CLKID_PERIF		5
+#define CLKID_PCUBE		6
+#define CLKID_VSCOPE		7
+#define CLKID_NFC_ECC		8
+#define CLKID_VPP		9
+#define CLKID_APP		10
+#define CLKID_SDIO0XIN		11
+#define CLKID_SDIO1XIN		12
+#define CLKID_GFX2DAXI		13
+#define CLKID_GETH0		14
+#define CLKID_SATA		15
+#define CLKID_AHBAPB		16
+#define CLKID_USB0		17
+#define CLKID_USB1		18
+#define CLKID_USB2		19
+#define CLKID_USB3		20
+#define CLKID_PBRIDGE		21
+#define CLKID_SDIO		22
+#define CLKID_NFC		23
+#define CLKID_SMEMC		24
+#define CLKID_PCIE		25
+#define CLKID_TWD		26
+#define CLKID_CPU		27