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| author | Paulo Alcantara <pc@manguebit.org> | 2026-09-26 19:20:30 -0300 |
|---|---|---|
| committer | Paulo Alcantara <pc@manguebit.org> | 2026-09-30 14:24:12 -0300 |
| commit | dd05add7b2b6004c5fa3a1f276f56d8668f86b65 (patch) | |
| tree | 23efdcaa0b8031f6ac6f57b6734d18d6c1adc6f2 /lib/vdso/Makefile.include | |
| download | linux-stable-dd05add7b2b6004c5fa3a1f276f56d8668f86b65.tar.gz linux-stable-dd05add7b2b6004c5fa3a1f276f56d8668f86b65.zip | |
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
Diffstat (limited to 'lib/vdso/Makefile.include')
| -rw-r--r-- | lib/vdso/Makefile.include | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/vdso/Makefile.include b/lib/vdso/Makefile.include new file mode 100644 index 000000000..cedbf15f8 --- /dev/null +++ b/lib/vdso/Makefile.include @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 + +GENERIC_VDSO_MK_PATH := $(abspath $(lastword $(MAKEFILE_LIST))) +GENERIC_VDSO_DIR := $(dir $(GENERIC_VDSO_MK_PATH)) + +c-gettimeofday-$(CONFIG_GENERIC_GETTIMEOFDAY) := $(addprefix $(GENERIC_VDSO_DIR), gettimeofday.c) +c-getrandom-$(CONFIG_VDSO_GETRANDOM) := $(addprefix $(GENERIC_VDSO_DIR), getrandom.c) + +# This cmd checks that the vdso library does not contain dynamic relocations. +# It has to be called after the linking of the vdso library and requires it +# as a parameter. +# +# As a workaround for some GNU ld ports which produce unneeded R_*_NONE +# dynamic relocations, ignore R_*_NONE. +quiet_cmd_vdso_check = VDSOCHK $@ + cmd_vdso_check = if $(READELF) -rW $@ | grep -v _NONE | grep -q " R_\w*_"; \ + then (echo >&2 "$@: dynamic relocations are not supported"; \ + rm -f $@; /bin/false); fi |