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| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2016-06-22 21:42:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-07 08:32:46 +0200 |
| commit | 625ddb785d013221458ab851ac718495eba1dcbf (patch) | |
| tree | ffaceada1c8c6bb3cc71bd552b42a672d6e27620 /kernel/user_namespace.c | |
| parent | dde898fba89069f78be1d0174f5184dc939cce5f (diff) | |
sysfs: correctly handle read offset on PREALLOC attrs
commit 17d0774f80681020eccc9638d925a23f1fc4f671 upstream.
Attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which returns
zero bytes for non-zero offset. This breaks script checkarray in mdadm tool
in debian where /bin/sh is 'dash' because its builtin 'read' reads only one
byte at a time. Script gets 'i' instead of 'idle' when reads current action
from /sys/block/$dev/md/sync_action and as a result does nothing.
This patch adds trivial implementation of partial read: generate whole
string and move required part into buffer head.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.")
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787950
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/user_namespace.c')
0 files changed, 0 insertions, 0 deletions