* [PATCH] timerfd: show procfs fdinfo helper @ 2013-12-24 16:33 Shawn Landden 2013-12-25 8:47 ` [CRIU] " Andrey Wagin 0 siblings, 1 reply; 5+ messages in thread From: Shawn Landden @ 2013-12-24 16:33 UTC (permalink / raw) Cc: criu, linux-fsdevel, linux-kernel, Shawn Landden, Thomas Gleixner, Alexander Viro | pos: 0 | flags: 02004002 | clockid: 0 Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Shawn Landden <shawn@churchofgit.com> --- fs/timerfd.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/fs/timerfd.c b/fs/timerfd.c index 9293121..e5fa587 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -25,6 +25,7 @@ #include <linux/syscalls.h> #include <linux/compat.h> #include <linux/rcupdate.h> +#include <linux/seq_file.h> struct timerfd_ctx { union { @@ -284,7 +285,23 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count, return res; } +#ifdef CONFIG_PROC_FS +static int timerfd_show_fdinfo(struct seq_file *m, struct file *f) +{ + struct timerfd_ctx *ctx = f->private_data; + int clockid; + + clockid = ctx->clockid; + seq_printf(m, "clockid:\t%d\n", clockid); + + return 0; +} +#endif + static const struct file_operations timerfd_fops = { +#ifdef CONFIG_PROC_FS + .show_fdinfo = timerfd_show_fdinfo, +#endif .release = timerfd_release, .poll = timerfd_poll, .read = timerfd_read, -- 1.8.5.2.297.g3e57c29 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [CRIU] [PATCH] timerfd: show procfs fdinfo helper 2013-12-24 16:33 [PATCH] timerfd: show procfs fdinfo helper Shawn Landden @ 2013-12-25 8:47 ` Andrey Wagin [not found] ` <7d057f57b1aa6dd3f6871c07374ff5a1@localhost> 0 siblings, 1 reply; 5+ messages in thread From: Andrey Wagin @ 2013-12-25 8:47 UTC (permalink / raw) To: Shawn Landden Cc: LKML, criu@openvz.org, Alexander Viro, linux-fsdevel, Thomas Gleixner 2013/12/24 Shawn Landden <shawn@churchofgit.com>: > | pos: 0 > | flags: 02004002 > | clockid: 0 > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Shawn Landden <shawn@churchofgit.com> > --- > fs/timerfd.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/fs/timerfd.c b/fs/timerfd.c > index 9293121..e5fa587 100644 > --- a/fs/timerfd.c > +++ b/fs/timerfd.c > @@ -25,6 +25,7 @@ > #include <linux/syscalls.h> > #include <linux/compat.h> > #include <linux/rcupdate.h> > +#include <linux/seq_file.h> > > struct timerfd_ctx { > union { > @@ -284,7 +285,23 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count, > return res; > } > > +#ifdef CONFIG_PROC_FS > +static int timerfd_show_fdinfo(struct seq_file *m, struct file *f) > +{ > + struct timerfd_ctx *ctx = f->private_data; > + int clockid; > + > + clockid = ctx->clockid; > + seq_printf(m, "clockid:\t%d\n", clockid); I think we can show ctx->ticks, itimerspec here. The ctx->ticks is required for proper dumping and restoring timerfd. > + > + return 0; > +} > +#endif > + > static const struct file_operations timerfd_fops = { > +#ifdef CONFIG_PROC_FS > + .show_fdinfo = timerfd_show_fdinfo, > +#endif > .release = timerfd_release, > .poll = timerfd_poll, > .read = timerfd_read, > -- > 1.8.5.2.297.g3e57c29 > > _______________________________________________ > CRIU mailing list > CRIU@openvz.org > https://lists.openvz.org/mailman/listinfo/criu ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <7d057f57b1aa6dd3f6871c07374ff5a1@localhost>]
* Re: [CRIU] [PATCH] timerfd: show procfs fdinfo helper [not found] ` <7d057f57b1aa6dd3f6871c07374ff5a1@localhost> @ 2014-02-03 10:44 ` Andrew Vagin 2014-02-03 16:01 ` [PATCH] timerfd: show procfs fdinfo helper, and now accepts write() Shawn Landden 0 siblings, 1 reply; 5+ messages in thread From: Andrew Vagin @ 2014-02-03 10:44 UTC (permalink / raw) To: shawn Cc: Andrey Wagin, LKML, criu@openvz.org, Alexander Viro, linux-fsdevel, Thomas Gleixner On Mon, Feb 03, 2014 at 01:24:41AM +0000, shawn@churchofgit.com wrote: > ---- Original Message ---- > From: "Andrey Wagin" <avagin@gmail.com> > To: "Shawn Landden" <shawn@churchofgit.com> > CC: "LKML" <linux-kernel@vger.kernel.org>, "criu@openvz.org" > <criu@openvz.org>, "Alexander Viro" <viro@zeniv.linux.org.uk>, > linux-fsdevel@vger.kernel.org, "Thomas Gleixner" <tglx@linutronix.de> > Sent: Wed, Dec 25, 2013, 12:46 AM > Subject: Re: [CRIU] [PATCH] timerfd: show procfs fdinfo helper > > > 2013/12/24 Shawn Landden <shawn@churchofgit.com>: > > | pos: 0 > | flags: 02004002 > | clockid: 0 > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Shawn Landden <shawn@churchofgit.com> > --- > fs/timerfd.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/fs/timerfd.c b/fs/timerfd.c > index 9293121..e5fa587 100644 > --- a/fs/timerfd.c > +++ b/fs/timerfd.c > @@ -25,6 +25,7 @@ > #include <linux/syscalls.h> > #include <linux/compat.h> > #include <linux/rcupdate.h> > +#include <linux/seq_file.h> > > struct timerfd_ctx { > union { > @@ -284,7 +285,23 @@ static ssize_t timerfd_read(struct file *file, > char __user *buf, size_t count, > return res; > } > > +#ifdef CONFIG_PROC_FS > +static int timerfd_show_fdinfo(struct seq_file *m, struct file *f) > +{ > + struct timerfd_ctx *ctx = f->private_data; > + int clockid; > + > + clockid = ctx->clockid; > + seq_printf(m, "clockid:\t%d\n", clockid); > > > > I think we can show ctx->ticks, itimerspec here. The ctx->ticks is > required for proper dumping and restoring timerfd. > > > How? Shouldn't the itemerspec (from timerfd_gettime and restored with > timerfd_settime) and clockid be enough? ctx->ticks is avaliable to userspace programs, so it must be restored, otherwise you can break applications, which use this parameter in own logic. > How do we put the ctx->ticks back into > the restored timerfd if we get it out with procfs? read(2) returns ctx->ticks, so write() can be used for set it. It you don't like this, you can add ioctl for setting ctx->ticks. > > + > + return 0; > +} > +#endif > + > static const struct file_operations timerfd_fops = { > +#ifdef CONFIG_PROC_FS > + .show_fdinfo = timerfd_show_fdinfo, > +#endif > .release = timerfd_release, > .poll = timerfd_poll, > .read = timerfd_read, > -- > 1.8.5.2.297.g3e57c29 > > _______________________________________________ > CRIU mailing list > CRIU@openvz.org > https://lists.openvz.org/mailman/listinfo/criu > > _______________________________________________ > CRIU mailing list > CRIU@openvz.org > https://lists.openvz.org/mailman/listinfo/criu ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] timerfd: show procfs fdinfo helper, and now accepts write() 2014-02-03 10:44 ` Andrew Vagin @ 2014-02-03 16:01 ` Shawn Landden 2014-02-04 20:00 ` Thomas Gleixner 0 siblings, 1 reply; 5+ messages in thread From: Shawn Landden @ 2014-02-03 16:01 UTC (permalink / raw) Cc: criu, linux-fsdevel, linux-kernel, avagin, Shawn Landden, Thomas Gleixner, Alexander Viro | pos: 0 | flags: 02004002 | clockid: 0 | ticks: 6 Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Shawn Landden <shawn@churchofgit.com> --- fs/timerfd.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/fs/timerfd.c b/fs/timerfd.c index 9293121..2e81bdb 100644 --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -25,6 +25,7 @@ #include <linux/syscalls.h> #include <linux/compat.h> #include <linux/rcupdate.h> +#include <linux/seq_file.h> struct timerfd_ctx { union { @@ -284,10 +285,73 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count, return res; } +#ifdef CONFIG_PROC_FS +static int timerfd_show_fdinfo(struct seq_file *m, struct file *f) +{ + struct timerfd_ctx *ctx = f->private_data; + + seq_printf(m, "clockid:\t%d\n" + "ticks:\t%llu\n", ctx->clockid, ctx->ticks); + + return 0; +} +#endif + +static ssize_t timerfd_write(struct file *file, const char __user *buf, size_t count, + loff_t *ppos) +{ + struct timerfd_ctx *ctx = file->private_data; + ssize_t res; + __u64 ucnt; + DECLARE_WAITQUEUE(wait, current); + + if (count < sizeof(ucnt)) + return -EINVAL; + if (copy_from_user(&ucnt, buf, sizeof(ucnt))) + return -EFAULT; + if (ucnt == ULLONG_MAX) + return -EINVAL; + spin_lock_irq(&ctx->wqh.lock); + res = -EAGAIN; + if (ULLONG_MAX - ctx->ticks > ucnt) + res = sizeof(ucnt); + else if (!(file->f_flags & O_NONBLOCK)) { + __add_wait_queue(&ctx->wqh, &wait); + for (res = 0;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (ULLONG_MAX - ctx->ticks > ucnt) { + res = sizeof(ucnt); + break; + } + if (signal_pending(current)) { + res = -ERESTARTSYS; + break; + } + spin_unlock_irq(&ctx->wqh.lock); + schedule(); + spin_lock_irq(&ctx->wqh.lock); + } + __remove_wait_queue(&ctx->wqh, &wait); + __set_current_state(TASK_RUNNING); + } + if (likely(res > 0)) { + ctx->ticks += ucnt; + if (waitqueue_active(&ctx->wqh)) + wake_up_locked_poll(&ctx->wqh, POLLIN); + } + spin_unlock_irq(&ctx->wqh.lock); + + return res; +} + static const struct file_operations timerfd_fops = { +#ifdef CONFIG_PROC_FS + .show_fdinfo = timerfd_show_fdinfo, +#endif .release = timerfd_release, .poll = timerfd_poll, .read = timerfd_read, + .write = timerfd_write, .llseek = noop_llseek, }; -- 1.8.5.2.297.g3e57c29 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] timerfd: show procfs fdinfo helper, and now accepts write() 2014-02-03 16:01 ` [PATCH] timerfd: show procfs fdinfo helper, and now accepts write() Shawn Landden @ 2014-02-04 20:00 ` Thomas Gleixner 0 siblings, 0 replies; 5+ messages in thread From: Thomas Gleixner @ 2014-02-04 20:00 UTC (permalink / raw) To: Shawn Landden; +Cc: criu, linux-fsdevel, linux-kernel, avagin, Alexander Viro On Mon, 3 Feb 2014, Shawn Landden wrote: > | pos: 0 > | flags: 02004002 > | clockid: 0 > | ticks: 6 This changelog is completely useless. It neither explains WHY we need to expose that fdinfo nor WHAT the write function is supposed to do. Aside of that the code lacks any comment and there is no documentation for the new user ABI. > Signed-off-by: Shawn Landden <shawn@churchofgit.com> I'm not going to find and read the bible of the churchofgit to figure out what this is all about. Thanks, tglx ^ permalink raw reply [flat|nested] 5+ messages in thread
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2013-12-24 16:33 [PATCH] timerfd: show procfs fdinfo helper Shawn Landden
2013-12-25 8:47 ` [CRIU] " Andrey Wagin
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2014-02-03 10:44 ` Andrew Vagin
2014-02-03 16:01 ` [PATCH] timerfd: show procfs fdinfo helper, and now accepts write() Shawn Landden
2014-02-04 20:00 ` Thomas Gleixner
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