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, 15 insertions, 0 deletions

diff --git a/drivers/phy/marvell/Makefile b/drivers/phy/marvell/Makefile
new file mode 100644
index 000000000..90862c4da
--- /dev/null
+++ b/drivers/phy/marvell/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)	+= phy-armada375-usb2.o
+obj-$(CONFIG_PHY_BERLIN_SATA)		+= phy-berlin-sata.o
+obj-$(CONFIG_PHY_BERLIN_USB)		+= phy-berlin-usb.o
+obj-$(CONFIG_PHY_MMP3_USB)		+= phy-mmp3-usb.o
+obj-$(CONFIG_PHY_MMP3_HSIC)		+= phy-mmp3-hsic.o
+obj-$(CONFIG_PHY_MVEBU_A3700_COMPHY)	+= phy-mvebu-a3700-comphy.o
+obj-$(CONFIG_PHY_MVEBU_A3700_UTMI)	+= phy-mvebu-a3700-utmi.o
+obj-$(CONFIG_PHY_MVEBU_A38X_COMPHY)	+= phy-armada38x-comphy.o
+obj-$(CONFIG_PHY_MVEBU_CP110_COMPHY)	+= phy-mvebu-cp110-comphy.o
+obj-$(CONFIG_PHY_MVEBU_CP110_UTMI)	+= phy-mvebu-cp110-utmi.o
+obj-$(CONFIG_PHY_MVEBU_SATA)		+= phy-mvebu-sata.o
+obj-$(CONFIG_PHY_PXA_28NM_HSIC)		+= phy-pxa-28nm-hsic.o
+obj-$(CONFIG_PHY_PXA_28NM_USB2)		+= phy-pxa-28nm-usb2.o
+obj-$(CONFIG_PHY_PXA_USB)		+= phy-pxa-usb.o