From 8d48b2e044218ba8b3f6b1d34e96a7474b6b0688 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Tue, 21 Aug 2018 21:54:23 -0700 Subject: [PATCH] proc: smaller readlock section in readdir("/proc") Readdir context is thread local, so ->pos is thread local, move it out of readlock. Link: http://lkml.kernel.org/r/20180627195339.GD18113@avx2 Signed-off-by: Alexey Dobriyan Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/generic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/proc/generic.c b/fs/proc/generic.c index bb1c1625b158..8ae109429a88 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -286,9 +286,9 @@ int proc_readdir_de(struct file *file, struct dir_context *ctx, if (!dir_emit_dots(file, ctx)) return 0; + i = ctx->pos - 2; read_lock(&proc_subdir_lock); de = pde_subdir_first(de); - i = ctx->pos - 2; for (;;) { if (!de) { read_unlock(&proc_subdir_lock); @@ -309,8 +309,8 @@ int proc_readdir_de(struct file *file, struct dir_context *ctx, pde_put(de); return 0; } - read_lock(&proc_subdir_lock); ctx->pos++; + read_lock(&proc_subdir_lock); next = pde_subdir_next(de); pde_put(de); de = next;