Eric W. Biederman 111c37fdf7 proc/fd: In fdinfo seq_show don't use get_files_struct ... [ Upstream commit 775e0656b27210ae668e33af00bece858f44576f ] When discussing[1] exec and posix file locks it was realized that none of the callers of get_files_struct fundamentally needed to call get_files_struct, and that by switching them to helper functions instead it will both simplify their code and remove unnecessary increments of files_struct.count. Those unnecessary increments can result in exec unnecessarily unsharing files_struct which breaking posix locks, and it can result in fget_light having to fallback to fget reducing system performance. Instead hold task_lock for the duration that task->files needs to be stable in seq_show. The task_lock was already taken in get_files_struct, and so skipping get_files_struct performs less work overall, and avoids the problems with the files_struct reference count. [1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> v1: https://lkml.kernel.org/r/20200817220425.9389-12-ebiederm@xmission.com Link: https://lkml.kernel.org/r/20201120231441.29911-17-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2024-11-19 12:27:28 +01:00
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array.c
base.c
bootconfig.c
cmdline.c
consoles.c
cpuinfo.c
devices.c
fd.c	proc/fd: In fdinfo seq_show don't use get_files_struct	2024-11-19 12:27:28 +01:00
fd.h
fslog.c
generic.c
inode.c
internal.h
interrupts.c
Kconfig
kcore.c
kmsg.c
loadavg.c
Makefile
meminfo.c
namespaces.c
nommu.c
page.c
proc_net.c
proc_sysctl.c
proc_tty.c
root.c
self.c
softirqs.c
stat.c
task_mmu.c
task_nommu.c
thread_self.c
uptime.c
util.c
version.c
vmcore.c