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, 31 insertions, 0 deletions

diff --git a/drivers/crypto/ccp/Makefile b/drivers/crypto/ccp/Makefile
new file mode 100644
index 000000000..0424e0856
--- /dev/null
+++ b/drivers/crypto/ccp/Makefile
@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_CRYPTO_DEV_CCP_DD) += ccp.o
+ccp-objs  := sp-dev.o sp-platform.o
+ccp-$(CONFIG_CRYPTO_DEV_SP_CCP) += ccp-dev.o \
+	    ccp-ops.o \
+	    ccp-dev-v3.o \
+	    ccp-dev-v5.o \
+	    ccp-dmaengine.o
+ccp-$(CONFIG_CRYPTO_DEV_CCP_DEBUGFS) += ccp-debugfs.o
+ccp-$(CONFIG_PCI) += sp-pci.o
+ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += psp-dev.o \
+                                   sev-dev.o \
+                                   tee-dev.o \
+                                   platform-access.o \
+                                   dbc.o \
+                                   hsti.o \
+                                   sfs.o
+
+ifeq ($(CONFIG_PCI_TSM),y)
+ccp-$(CONFIG_CRYPTO_DEV_SP_PSP) += sev-dev-tsm.o sev-dev-tio.o
+endif
+
+obj-$(CONFIG_CRYPTO_DEV_CCP_CRYPTO) += ccp-crypto.o
+ccp-crypto-objs := ccp-crypto-main.o \
+		   ccp-crypto-aes.o \
+		   ccp-crypto-aes-cmac.o \
+		   ccp-crypto-aes-xts.o \
+		   ccp-crypto-aes-galois.o \
+		   ccp-crypto-des3.o \
+		   ccp-crypto-rsa.o \
+		   ccp-crypto-sha.o