[RFC 05/18] limits: track and present RLIMIT_NOFILE actual max
[Posted July 13, 2016 by jake]
| From: |
| Topi Miettinen <toiwoton-AT-gmail.com> |
| To: |
| linux-kernel-AT-vger.kernel.org |
| Subject: |
| [RFC 05/18] limits: track and present RLIMIT_NOFILE actual max |
| Date: |
| Mon, 13 Jun 2016 22:44:12 +0300 |
| Message-ID: |
| <1465847065-3577-6-git-send-email-toiwoton@gmail.com> |
| Cc: |
| Topi Miettinen <toiwoton-AT-gmail.com>, Alexander Viro <viro-AT-zeniv.linux.org.uk>, Ingo Molnar <mingo-AT-redhat.com>, Peter Zijlstra <peterz-AT-infradead.org>, Andrew Morton <akpm-AT-linux-foundation.org>, Kees Cook <keescook-AT-chromium.org>, Cyrill Gorcunov <gorcunov-AT-openvz.org>, Alexey Dobriyan <adobriyan-AT-gmail.com>, John Stultz <john.stultz-AT-linaro.org>, Janis Danisevskis <jdanis-AT-google.com>, Calvin Owens <calvinowens-AT-fb.com>, Jann Horn <jann-AT-thejh.net>, linux-fsdevel-AT-vger.kernel.org (open list:FILESYSTEMS (VFS and infrastructure)) |
| Archive‑link: | |
Article |
Track maximum number of files for the process, present current maximum
in /proc/self/limits.
Signed-off-by: Topi Miettinen <toiwoton@gmail.com>
---
fs/file.c | 4 ++++
fs/proc/base.c | 10 ++++++----
include/linux/sched.h | 7 +++++++
3 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/fs/file.c b/fs/file.c
index 6b1acdf..2d0d206 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -547,6 +547,8 @@ repeat:
}
#endif
+ bump_rlimit(RLIMIT_NOFILE, fd);
+
out:
spin_unlock(&files->file_lock);
return error;
@@ -857,6 +859,8 @@ __releases(&files->file_lock)
if (tofree)
filp_close(tofree, files);
+ bump_rlimit(RLIMIT_NOFILE, fd);
+
return fd;
Ebusy:
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a11eb71..227997b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -630,8 +630,8 @@ static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
/*
* print the file header
*/
- seq_printf(m, "%-25s %-20s %-20s %-10s\n",
- "Limit", "Soft Limit", "Hard Limit", "Units");
+ seq_printf(m, "%-25s %-20s %-20s %-10s %-20s\n",
+ "Limit", "Soft Limit", "Hard Limit", "Units", "Max");
for (i = 0; i < RLIM_NLIMITS; i++) {
if (rlim[i].rlim_cur == RLIM_INFINITY)
@@ -647,9 +647,11 @@ static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
seq_printf(m, "%-20lu ", rlim[i].rlim_max);
if (lnames[i].unit)
- seq_printf(m, "%-10s\n", lnames[i].unit);
+ seq_printf(m, "%-10s", lnames[i].unit);
else
- seq_putc(m, '\n');
+ seq_printf(m, "%-10s", "");
+ seq_printf(m, "%-20lu\n",
+ task->signal->rlim_curmax[i]);
}
return 0;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 9c48a08..0150380 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -782,6 +782,7 @@ struct signal_struct {
* have no need to disable irqs.
*/
struct rlimit rlim[RLIM_NLIMITS];
+ unsigned long rlim_curmax[RLIM_NLIMITS];
#ifdef CONFIG_BSD_PROCESS_ACCT
struct pacct_struct pacct; /* per-process accounting information */
@@ -3376,6 +3377,12 @@ static inline unsigned long rlimit_max(unsigned int limit)
return task_rlimit_max(current, limit);
}
+static inline void bump_rlimit(unsigned int limit, unsigned long r)
+{
+ if (READ_ONCE(current->signal->rlim_curmax[limit]) < r)
+ current->signal->rlim_curmax[limit] = r;
+}
+
#ifdef CONFIG_CPU_FREQ
struct update_util_data {
void (*func)(struct update_util_data *data,
--
2.8.1
