procfs fdinfo extension, new round
Subsystems (6)
cover procfs fdinfo extension, new round
Hi, here is a bit updated version of patches for procfs fdinfo outpu extension (which we need to be able to restore eventfd/epoll/inotify files).
I tried to addess Matthew's and Pavel's comments (well, I rather didn't inject new member into
file_operations structure and comment in change log will explain why).
Please review, and thanks a lot for previous feedback!
PATCH 1/7 procfs: Move /proc/pid/fd[info] handling code to fd.[ch]
This patch prepares the ground for further extension of /proc/pid/fd[info] handling code by moving fdinfo handling code into fs/proc/fd.c.
I think such move makes both fs/proc/base.c and fs/proc/fd.c easier to read.
--- fs/proc/Makefile | 2 fs/proc/base.c | 388 ----------------------------------------------------- fs/proc/fd.c | 351 +++++++++++++++++++++++++++++++++++++++++++++++ fs/proc/fd.h | 14 + fs/proc/internal.h | 48 ++++++ 5 files changed, 416 insertions(+), 387 deletions(-)
fs/proc/Makefile +1 -1
@@ -8,7 +8,7 @@ proc-y := nommu.o task_nommu.o proc-$(CONFIG_MMU) := mmu.o task_mmu.o proc-y += inode.o root.o base.o generic.o array.o \ - proc_tty.o + proc_tty.o fd.o proc-y += cmdline.o proc-y += consoles.o proc-y += cpuinfo.o
fs/proc/base.c +2 -386
430 lines not on this page · raw message
fs/proc/fd.c new file +351 -0
351 lines not on this page · raw message
fs/proc/fd.h new file +14 -0
@@ -0,0 +1,14 @@ +#ifndef __PROCFS_FD_H__ +#define __PROCFS_FD_H__ + +#include <linux/fs.h> + +extern const struct file_operations proc_fd_operations; +extern const struct inode_operations proc_fd_inode_operations; + +extern const struct file_operations proc_fdinfo_operations; +extern const struct inode_operations proc_fdinfo_inode_operations; + +extern int proc_fd_permission (struct inode *inode,int mask); + +#endif /* __PROCFS_FD_H__ */
fs/proc/internal.h +48 -0
66 lines not on this page · raw message
PATCH 2/7 procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file
In reply to Cyrill GorcunovThis patch converts /proc/pid/fdinfo/ handling routines to seq-file which is needed to extend seq operations and plug in auxiliary fdinfo provides from subsystems like eventfd/eventpoll/fsnotify.
Note the proc_fd_link no longer call for proc_fd_info, simply because proc_fd_info is converted to seq_fdinfo_open (which is seq-file open() prototype), moreover in further patches I need to provide two seq_fdinfo_open variants -- one with CONFIG_CHECKPOINT_RESTORE and one without this symbol. All in one -- this will look more messy then.
--- fs/proc/fd.c | 133 +++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 85 insertions(+), 48 deletions(-)
fs/proc/fd.c +85 -48
@@ -6,61 +6,90 @@#include <linux/namei.h> #include <linux/pid.h> #include <linux/security.h> +#include <linux/file.h> +#include <linux/seq_file.h> #include <linux/proc_fs.h> #include "internal.h" #include "fd.h" -#define PROC_FDINFO_MAX 64 +struct proc_fdinfo { +loff_t f_pos; +int f_flags; +}; -static int proc_fd_info (struct inode *inode,struct path *path,char *info) +static int seq_show (struct seq_file *m,void *v) +{ +struct proc_fdinfo *fdinfo = m->private; +seq_printf (m,"pos:\t%lli\nflags:\t0%o\n" , + (long long )fdinfo->f_pos, + fdinfo->f_flags); +return 0 ; +} + +static int seq_fdinfo_open (struct inode *inode,struct file *file) { -struct task_struct *task =get_proc_task (inode);struct files_struct *files =NULL ; -int fd =proc_fd (inode); -struct file *file; +struct proc_fdinfo *fdinfo =NULL ; +struct task_struct *task; +int ret = -ENOENT ; + + fdinfo =kzalloc (sizeof (*fdinfo),GFP_KERNEL ); +if (!fdinfo) +return -ENOMEM ; + task =get_proc_task (inode);if (task) { files =get_files_struct (task);put_task_struct (task); } +if (files) { -/* -* We are not taking a ref to the file structure, so we must -* hold ->file_lock. -*/ +int fd =proc_fd (inode); +struct file *fd_file; +spin_lock (&files->file_lock); - file =fcheck_files (files, fd); -if (file) { -unsigned int f_flags; -struct fdtable *fdt; + fd_file =fcheck_files (files, fd); +if (fd_file) { +struct fdtable *fdt =files_fdtable (files); - fdt =files_fdtable (files); - f_flags = file->f_flags & ~O_CLOEXEC ; + fdinfo->f_flags = fd_file->f_flags & ~O_CLOEXEC ;if (close_on_exec (fd, fdt)) - f_flags |=O_CLOEXEC ; - -if (path) { - *path = file->f_path; -path_get (&file->f_path); - } -if (info) -snprintf (info,PROC_FDINFO_MAX , -"pos:\t%lli\n" -"flags:\t0%o\n" , - (long long ) file->f_pos, - f_flags); -spin_unlock (&files->file_lock); -put_files_struct (files); -return 0 ; + fdinfo->f_flags |=O_CLOEXEC ; + ret =0 ; }spin_unlock (&files->file_lock);put_files_struct (files); } -return -ENOENT ; + +if (!ret) { + ret =single_open (file, seq_show, fdinfo); +if (!ret) + fdinfo =NULL ; + } + +kfree (fdinfo); +return ret; +} + +static int seq_fdinfo_release (struct inode *inode,struct file *file) +{ +struct seq_file *m = file->private_data; +struct proc_fdinfo *fdinfo = m->private; + +kfree (fdinfo); + +return single_release (inode, file); } +static const struct file_operations proc_fdinfo_file_operations = { + .open = seq_fdinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_fdinfo_release, +}; +static int tid_fd_revalidate (struct dentry *dentry,struct nameidata *nd) {struct files_struct *files;
@@ -130,7 +159,31 @@ static const struct dentry_operations tistatic int proc_fd_link (struct dentry *dentry,struct path *path) { -return proc_fd_info (dentry->d_inode, path,NULL ); +struct inode *inode = dentry->d_inode; +struct task_struct *task =get_proc_task (inode); +struct files_struct *files =NULL ; +int fd =proc_fd (inode); +struct file *file; +int err = -ENOENT ; + +if (task) { + files =get_files_struct (task); +put_task_struct (task); + } + +if (files) { +spin_lock (&files->file_lock); + file =fcheck_files (files, fd); +if (file) { + *path = file->f_path; +path_get (&file->f_path); + } +spin_unlock (&files->file_lock); +put_files_struct (files); + err =0 ; + } + +return err; } static struct dentry *
@@ -245,22 +298,6 @@ out_no_task:return retval; } -static ssize_t proc_fdinfo_read (struct file *file,char __user *buf, -size_t len,loff_t *ppos) -{ -char tmp[PROC_FDINFO_MAX ]; -int err =proc_fd_info (file->f_path.dentry->d_inode,NULL , tmp); -if (!err) - err =simple_read_from_buffer (buf, len, ppos, tmp,strlen (tmp)); -return err; -} - -static const struct file_operations proc_fdinfo_file_operations = { - .open = nonseekable_open, - .read = proc_fdinfo_read, - .llseek = no_llseek, -}; -static int proc_readfd (struct file *filp,void *dirent,filldir_t filldir) {return proc_readfd_common (filp, dirent, filldir, proc_fd_instantiate);
Re: [patch 2/7] procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file
Quoted 9 lines · Cyrill Gorcunov
This patch converts
/proc/pid/fdinfo/handling routines to seq-file which is needed to extend seq operations and plug in auxiliary fdinfo provides from subsystems like eventfd/eventpoll/fsnotify.Note the
proc_fd_linkno longer call forproc_fd_info, simply becauseproc_fd_infois converted toseq_fdinfo_open(which is seq-fileopen()prototype), moreover in further patches I need to provide twoseq_fdinfo_openvariants -- one withCONFIG_CHECKPOINT_RESTOREand one without this symbol. All in one -- this will look more messy then.
This is something I'm really not happy with :( After the set applied we will have one former proc_fd_info being splitted into 3 (three!) functions doing the same (with flavors).
For me it's better to fix this, otherwise conversion to seq-file looks OK.
Quoted 9 lines
Signed-off-by Cyrill Gorcunov <[email protected]>CC Al Viro <[email protected]>CC Alexey Dobriyan <[email protected]>CC Andrew Morton <[email protected]>CC Pavel Emelyanov <[email protected]>CC James Bottomley <[email protected]>--- fs/proc/fd.c | 133 +++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 85 insertions(+), 48 deletions(-)
Re: [patch 2/7] procfs: Convert /proc/pid/fdinfo/ handling routines to seq-file
Quoted 11 lines · Pavel Emelyanov
Quoted 9 lines · Cyrill Gorcunov
This patch converts
/proc/pid/fdinfo/handling routines to seq-file which is needed to extend seq operations and plug in auxiliary fdinfo provides from subsystems like eventfd/eventpoll/fsnotify.Note the
proc_fd_linkno longer call forproc_fd_info, simply becauseproc_fd_infois converted toseq_fdinfo_open(which is seq-fileopen()prototype), moreover in further patches I need to provide twoseq_fdinfo_openvariants -- one withCONFIG_CHECKPOINT_RESTOREand one without this symbol. All in one -- this will look more messy then.
Quoted 5 lines
This is something I'm really not happy with :( After the set applied we will have one former
proc_fd_infobeing splitted into 3 (three!) functions doing the same (with flavors).For me it's better to fix this, otherwise conversion to seq-file looks OK.
OK, thanks for review! I'll try to fix it up.
Cyrill
PATCH 3/7 procfs: Add ability to plug in auxiliary fdinfo providers
In reply to Cyrill GorcunovThis patch brings ability to plug in auxiliary fdinfo providers. For example in further patches eventfd, evenpoll and fsnotify will print out information associated with files.
This feature is CONFIG_CHECKPOINT_RESTORE guarded to eliminate overhead for those who don't need it at all (this unfortunately makes patch bigger than I wanted).
The basic usage rule is the following
- fdinfo provider should register own "show" method via proc_register_fdinfo_driver call, where "show" methods are rather well known seq-file operations
- once the kernel opens /proc/$pid/fdinfo/$fd file it calls for ->probe() method in registered fdinfo drivers, and if probe success, then seq-file "show" operations will be called to provide out additional infomation
Initially we considered to inject some "show" metod to file_operations but since there really a number of file_operations declared inside kernel (and in real the further patches cover onle eventfd/epoll/inotify) the waste of memory space will be inacceptable I think.
--- fs/proc/fd.c | 200 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/proc_fs.h | 26 ++++++ 2 files changed, 226 insertions(+)
fs/proc/fd.c +200 -0
@@ -8,12 +8,210 @@#include <linux/security.h> #include <linux/file.h> #include <linux/seq_file.h> +#include <linux/spinlock.h> #include <linux/proc_fs.h> #include "internal.h" #include "fd.h" +#ifdef CONFIG_CHECKPOINT_RESTORE + +static LIST_HEAD(fdinfo_drivers); +static DECLARE_RWSEM(fdinfo_drivers_sem); + +int proc_register_fdinfo_driver(struct proc_fdinfo_driver *s) +{ + struct proc_fdinfo_driver *i; + int ret = 0; + + if (!s->ops || !s->probe) + return -EINVAL; + + down_write(&fdinfo_drivers_sem); + list_for_each_entry(i, &fdinfo_drivers, list) { + if (i == s) { + WARN_ONCE("Trying reassign fdinfo driver `%s'\n", + i->name); + ret = -EINVAL; + break; + } + } + if (!ret) + list_add(&s->list, &fdinfo_drivers); + up_write(&fdinfo_drivers_sem); + + return ret; +} + +void proc_unregister_fdinfo_driver(struct proc_fdinfo_driver *s) +{ + struct proc_fdinfo_driver *i, *tmp; + + down_write(&fdinfo_drivers_sem); + list_for_each_entry_safe(i, tmp, &fdinfo_drivers, list) { + if (i == s) { + list_del(&i->list); + break; + } + } + up_write(&fdinfo_drivers_sem); +} + +static int prep_fdinfo_driver(struct proc_fdinfo_extra *extra) +{ + struct proc_fdinfo_driver *s; + + down_read(&fdinfo_drivers_sem); + list_for_each_entry(s, &fdinfo_drivers, list) { + if (s->probe(extra->f_file)) { + extra->driver = s; + break; + } + } + up_read(&fdinfo_drivers_sem); + + return 0; +} + +static void *seq_start(struct seq_file *m, loff_t *pos) +{ + struct proc_fdinfo_extra *extra = m->private; + + down_read(&fdinfo_drivers_sem); + extra->pos = *pos; + + return *pos == 0 ? extra : + (extra->driver ? extra->driver->ops->start(m, pos) : NULL); +} + +static void seq_stop(struct seq_file *m, void *v) +{ + struct proc_fdinfo_extra *extra = m->private; + + if (extra->driver && extra->pos > 0) + extra->driver->ops->stop(m, v); + up_read(&fdinfo_drivers_sem); +} + +static void *seq_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct proc_fdinfo_extra *extra = m->private; + void *v = NULL; + + if (extra->driver) { + int ret = 0; + + if (*pos == 0) { + v = extra->driver->ops->start(m, pos); + if (v) { + ret = extra->driver->ops->show(m, v); + p = v; + } else + ret = -1; + } + + if (!ret) + v = extra->driver->ops->next(m, p, pos); + } else + ++*pos; + + extra->pos = *pos; + return v; +} + +static int seq_show(struct seq_file *m, void *v) +{ + struct proc_fdinfo_extra *extra = m->private; + + if (extra->driver && extra->pos > 0) + return extra->driver->ops->show(m, v); + + seq_printf(m, "pos:\t%lli\nflags:\t0%o\n", + (long long)extra->f_file->f_pos, + extra->f_flags); + return 0; +} + +static const struct seq_operations fdinfo_seq_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static int seq_fdinfo_open(struct inode *inode, struct file *file) +{ + struct files_struct *files = NULL; + struct proc_fdinfo_extra *extra; + struct task_struct *task; + struct seq_file *m; + int ret; + + extra = kzalloc(sizeof(*extra), GFP_KERNEL); + if (!extra) + return -ENOMEM; + + ret = seq_open(file, &fdinfo_seq_ops); + if (!ret) { + ret = -ENOENT; + m = file->private_data; + m->private = extra; + + task = get_proc_task(inode); + if (task) { + files = get_files_struct(task); + put_task_struct(task); + } + + if (files) { + int fd = proc_fd(inode); + + spin_lock(&files->file_lock); + extra->f_file = fcheck_files(files, fd); + if (extra->f_file) { + struct fdtable *fdt = files_fdtable(files); + + extra->f_flags = extra->f_file->f_flags & ~O_CLOEXEC; + if (close_on_exec(fd, fdt)) + extra->f_flags |= O_CLOEXEC; + get_file(extra->f_file); + } + spin_unlock(&files->file_lock); + put_files_struct(files); + + ret = prep_fdinfo_driver(extra); + } + } + + if (ret) { + if (extra->f_file) + put_filp(extra->f_file); + kfree(extra); + } + return ret; +} + +static int seq_fdinfo_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct proc_fdinfo_extra *extra = m->private; + + put_filp(extra->f_file); + kfree(m->private); + + return seq_release(inode, file); +} + +static const struct file_operations proc_fdinfo_file_operations = { + .open = seq_fdinfo_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_fdinfo_release, +}; + +#else /* CONFIG_CHECKPOINT_RESTORE */ + struct proc_fdinfo { loff_t f_pos; int f_flags;
@@ -90,6 +288,8 @@ static const struct file_operations proc .release = seq_fdinfo_release, }; +#endif /* CONFIG_CHECKPOINT_RESTORE */ +static int tid_fd_revalidate (struct dentry *dentry,struct nameidata *nd) {struct files_struct *files;
include/linux/proc_fs.h +26 -0
@@ -100,6 +100,24 @@ struct vmcore {loff_t offset; }; +struct seq_operations ; + +/* fdinfo auxiliary information drivers */ +struct proc_fdinfo_driver { +struct list_head list; +const char *name; +const struct seq_operations *ops; +int (*probe)(struct file *file); +}; + +/* auxiliary data allocated per fdinfo reader */ +struct proc_fdinfo_extra { +struct proc_fdinfo_driver *driver; +loff_t pos; +struct file *f_file; +unsigned int f_flags; +}; +#ifdef CONFIG_PROC_FS extern void proc_root_init (void );
@@ -175,6 +193,11 @@ extern struct proc_dir_entry *proc_net_mextern struct file *proc_ns_fget (int fd); +#ifdef CONFIG_CHECKPOINT_RESTORE +extern int proc_register_fdinfo_driver (struct proc_fdinfo_driver *s); +extern void proc_unregister_fdinfo_driver (struct proc_fdinfo_driver *s); +#endif /* CONFIG_CHECKPOINT_RESTORE */ +#else #define proc_net_fops_create (net, name, mode, fops) ({ (void)(mode), NULL; })
@@ -229,6 +252,9 @@ static inline struct file *proc_ns_fget( return ERR_PTR(-EINVAL); } +static inline int proc_register_fdinfo_driver (struct proc_fdinfo_driver *s) {return -EINVAL ; } +static inline void proc_unregister_fdinfo_driver (struct proc_fdinfo_driver *s) { } +#endif /* CONFIG_PROC_FS */ #if !defined(CONFIG_PROC_KCORE )
Re: [patch 3/7] procfs: Add ability to plug in auxiliary fdinfo providers
Quoted 5 lines
fs/proc/fd.c +5
-0+static int prep_fdinfo_driver (struct proc_fdinfo_extra *extra) +{ +struct proc_fdinfo_driver *s; + +down_read (&fdinfo_drivers_sem);
fs/proc/fd.c line 75
Quoted 10 lines
fs/proc/fd.c +10
-0+list_for_each_entry (s, &fdinfo_drivers, list) { +if (s->probe (extra->f_file)) { + extra->driver = s; +break ; + } + } +up_read (&fdinfo_drivers_sem); + +return 0 ; +}
Maybe a simple list of file_operations:seq_operations mappings would be simpler?
fs/proc/fd.c line 108
Quoted 12 lines
fs/proc/fd.c +12
-0+static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +void *v =NULL ; + +if (extra->driver) { +int ret =0 ; + +if (*pos ==0 ) { + v = extra->driver->ops->start (m, pos); +if (v) { + ret = extra->driver->ops->show (m, v);
Why is it necessary to call ->show here? The logic should be
seq_start = (pos == 0 ? nop : extra->start)
seq_next = (pos == 0 ? extra->start : extra->next) seq_stop = (pos == 0 ? nop : extra->stop) seq_show = (pos == 0 ? proc_show : extra->show)
Or I'm missing something?
Thanks,
Pavel
Re: [patch 3/7] procfs: Add ability to plug in auxiliary fdinfo providers
Quoted 9 lines · Pavel Emelyanov
Quoted 9 lines
fs/proc/fd.c +9
-0+static int prep_fdinfo_driver (struct proc_fdinfo_extra *extra) +{ +struct proc_fdinfo_driver *s; + +down_read (&fdinfo_drivers_sem); +list_for_each_entry (s, &fdinfo_drivers, list) { +if (s->probe (extra->f_file)) { + extra->driver = s; +break ;
Quoted 8 lines
fs/proc/fd.c line 75
Quoted 6 lines
fs/proc/fd.c +6
-0+ } + } +up_read (&fdinfo_drivers_sem); + +return 0 ; +}Maybe a simple list of file_operations:seq_operations mappings would be simpler?
Yeah, I thought about it. This seems to be a way more simplier. I think i'll switch to this.
Quoted 16 lines
fs/proc/fd.c line 108
Quoted 13 lines
fs/proc/fd.c +12
-0+static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +void *v =NULL ; + +if (extra->driver) { +int ret =0 ; + +if (*pos ==0 ) { + v = extra->driver->ops->start (m, pos); +if (v) { + ret = extra->driver->ops->show (m, v);Why is it necessary to call ->show here? The logic should be
Quoted 6 lines
seq_start= (pos == 0 ? nop :extra->start)seq_next = (pos == 0 ? extra->start : extra->next) seq_stop = (pos == 0 ? nop : extra->stop) seq_show = (pos == 0 ? proc_show : extra->show)Or I'm missing something?
Well, I thought about it as two sequences -- first is procfs seq-file, which prints out a general header, and second is extra fdinfo provider.
Everything starts with printing procfs header
seq_start -> seq_show (prints "pos:\t%lli\nflags:\t0%o\n") -> seq_next -> (if have extra driver we do extra's start/show at first, then next and etc). In other words general header should be shown always even if extra's start() fails.
Cyrill
Re: [patch 3/7] procfs: Add ability to plug in auxiliary fdinfo providers
Quoted 22 lines
Quoted 15 lines
fs/proc/fd.c line 108
Quoted 12 lines
fs/proc/fd.c +12
-0+static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +void *v =NULL ; + +if (extra->driver) { +int ret =0 ; + +if (*pos ==0 ) { + v = extra->driver->ops->start (m, pos); +if (v) { + ret = extra->driver->ops->show (m, v);Why is it necessary to call ->show here? The logic should be
Quoted 6 lines
seq_start= (pos == 0 ? nop :extra->start)seq_next = (pos == 0 ? extra->start : extra->next) seq_stop = (pos == 0 ? nop : extra->stop) seq_show = (pos == 0 ? proc_show : extra->show)Or I'm missing something?
Quoted 8 lines
Well, I thought about it as two sequences -- first is procfs seq-file, which prints out a general header, and second is extra fdinfo provider.
Everything starts with printing procfs header
seq_start->seq_show(prints "pos:\t%lli\nflags:\t0%o\n") ->seq_next-> (if have extra driver we do extra's start/show at first,
Why show? The generic seq_file.c will call ->next (which will result in extra->start), then ->show (which _should_ result in extra->show) thus providing correct output.
Quoted 6 lines
then next and etc). In other words general header should be shown always even if extra's
start()fails.Cyrill
.
Re: [patch 3/7] procfs: Add ability to plug in auxiliary fdinfo providers
Quoted 26 lines · Pavel Emelyanov
Quoted 26 lines
Quoted 15 lines
fs/proc/fd.c line 108
Quoted 12 lines
fs/proc/fd.c +12
-0+static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +void *v =NULL ; + +if (extra->driver) { +int ret =0 ; + +if (*pos ==0 ) { + v = extra->driver->ops->start (m, pos); +if (v) { + ret = extra->driver->ops->show (m, v);Why is it necessary to call ->show here? The logic should be
Quoted 6 lines
seq_start= (pos == 0 ? nop :extra->start)seq_next = (pos == 0 ? extra->start : extra->next) seq_stop = (pos == 0 ? nop : extra->stop) seq_show = (pos == 0 ? proc_show : extra->show)Or I'm missing something?
Well, I thought about it as two sequences -- first is procfs seq-file, which prints out a general header, and second is extra fdinfo provider.
Quoted 8 lines
Quoted 4 lines
Everything starts with printing procfs header
seq_start->seq_show(prints "pos:\t%lli\nflags:\t0%o\n") ->seq_next-> (if have extra driver we do extra's start/show at first,Why show? The generic
seq_file.cwill call ->next (which will result inextra->start), then ->show (which _should_ result inextra->show) thus providing correct output.
Yes, indeed i think i've made it more complex than it should be. Will update, thanks!
Cyrill
PATCH 4/7 fs, eventfd: Add procfs fdinfo helper
In reply to Cyrill GorcunovThis allow us to print out raw counter value. The /proc/pid/fdinfo/fd output is
| pos: 0 | flags: 04002 | eventfd-count: 5a
This feature is CONFIG_CHECKPOINT_RESTORE only.
--- fs/eventfd.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+)
fs/eventfd.c +55 -0
@@ -19,6 +19,8 @@#include <linux/export.h> #include <linux/kref.h> #include <linux/eventfd.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> struct eventfd_ctx {struct kref kref;
@@ -433,3 +435,56 @@ SYSCALL_DEFINE1(eventfd, unsigned int, creturn sys_eventfd2 (count,0 ); } +#if defined(CONFIG_PROC_FS ) && defined(CONFIG_CHECKPOINT_RESTORE ) + +static void *seq_start (struct seq_file *m,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +return *pos ==0 ? extra->f_file :NULL ; +} + +static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ + ++*pos; +return NULL ; +} + +static int seq_show (struct seq_file *m,void *v) +{ +struct eventfd_ctx *ctx = ((struct file *)v)->private_data; + +spin_lock_irq (&ctx->wqh.lock); +seq_printf (m,"eventfd-count: %16llx\n" , + (unsigned long long )ctx->count); +spin_unlock_irq (&ctx->wqh.lock); + +return 0 ; +} + +static void seq_stop (struct seq_file *p,void *v) { } + +static const struct seq_operations eventfd_fdinfo_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static int is_eventfd_file (struct file *file) +{ +return file->f_op == &eventfd_fops; +} + +static struct proc_fdinfo_driver eventfd_fdinfo = { + .name ="eventfd" , + .ops = &eventfd_fdinfo_ops, + .probe = is_eventfd_file, +}; + +static int __init eventfd_init (void ) +{ +return proc_register_fdinfo_driver (&eventfd_fdinfo); +} +fs_initcall (eventfd_init); + +#endif /* CONFIG_PROC_FS && CONFIG_CHECKPOINT_RESTORE */
PATCH 5/7 fs, epoll: Add procfs fdinfo helper v2
In reply to Cyrill GorcunovThis allow us to print out eventpoll target file descriptor, events and data, the /proc/pid/fdinfo/fd consists of
| pos: 0 | flags: 02 | tfd: 5 events: 1d data: ffffffffffffffff
This feature is CONFIG_CHECKPOINT_RESTORE only.
v2:
- don't walk over all rb nodes on seq-next,
try to continue from pervious position
--- fs/eventpoll.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+)
fs/eventpoll.c +67 -0
@@ -38,6 +38,8 @@#include <asm/io.h> #include <asm/mman.h> #include <linux/atomic.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> /* * LOCKING:
@@ -1897,6 +1899,69 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd,return error; } +#if defined(CONFIG_PROC_FS ) && defined(CONFIG_CHECKPOINT_RESTORE ) + +static void *seq_start (struct seq_file *m,loff_t *pos) +{ +struct proc_fdinfo_extra *extra = m->private; +struct eventpoll *ep = extra->f_file->private_data; +struct rb_node *rbp; +loff_t num = *pos; + +mutex_lock (&ep->mtx); +for (rbp =rb_first (&ep->rbr); rbp; rbp =rb_next (rbp)) { +if (num-- ==0 ) +return rbp; + } + +return NULL ; +} + +static void seq_stop (struct seq_file *m,void *v) +{ +struct proc_fdinfo_extra *extra = m->private; +struct eventpoll *ep = extra->f_file->private_data; +mutex_unlock (&ep->mtx); +} + +static void *seq_next (struct seq_file *m,void *p,loff_t *pos) +{ +struct rb_node *rbp = p; + ++*pos; +return (void *)rb_next (rbp); +} + +static int seq_show (struct seq_file *m,void *v) +{ +struct rb_node *rbp = v; + struct epitem *epi = rb_entry(rbp, struct epitem, rbn); + +return seq_printf (m,"tfd: %8d events: %8x data: %16llx\n" , + epi->ffd.fd, epi->event.events, + (long long )epi->event.data); +} + +static const struct seq_operations ep_fdinfo_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static struct proc_fdinfo_driver ep_fdinfo = { + .name ="eventpoll" , + .ops = &ep_fdinfo_ops, + .probe = is_file_epoll, +}; + +static int __init ep_register_fdinfo_driver (void ) +{ +return proc_register_fdinfo_driver (&ep_fdinfo); +} +#else +static void ep_register_fdinfo_driver (void ) { } +#endif /* CONFIG_PROC_FS && CONFIG_CHECKPOINT_RESTORE */ +static int __init eventpoll_init (void ) {struct sysinfo si;
@@ -1929,6 +1994,8 @@ static int __init eventpoll_init(void) pwq_cache =kmem_cache_create ("eventpoll_pwq" ,sizeof (struct eppoll_entry ),0 ,SLAB_PANIC ,NULL ); +ep_register_fdinfo_driver (); +return 0 ; }fs_initcall (eventpoll_init);
PATCH 6/7 fs, exportfs: Add export_encode_inode_fh helper
In reply to Cyrill GorcunovTo provide fsnotify object inodes being watched without binding to alphabetical path we need to encode them with exportfs help. This patch adds a helper which operates with plain inodes directly.
This feature is CONFIG_CHECKPOINT_RESTORE only.
--- fs/exportfs/expfs.c | 21 +++++++++++++++++++++ include/linux/exportfs.h | 4 ++++ 2 files changed, 25 insertions(+)
fs/exportfs/expfs.c +21 -0
@@ -302,6 +302,27 @@ out:return error; } +#ifdef CONFIG_CHECKPOINT_RESTORE +int export_encode_inode_fh (struct inode *inode,struct fid *fid,int *max_len) +{ +int len = *max_len; +int type =FILEID_INO32_GEN ; + +if (len <2 ) { + *max_len =2 ; +return 255 ; + } + + len =2 ; + fid->i32.ino = inode->i_ino; + fid->i32.gen = inode->i_generation; + *max_len = len; + +return type; +} +EXPORT_SYMBOL_GPL (export_encode_inode_fh); +#endif +/** * export_encode_fh - default export_operations->encode_fh function * @inode: the object to encode
include/linux/exportfs.h +4 -0
@@ -177,6 +177,10 @@ struct export_operations {int (*commit_metadata)(struct inode *inode); }; +#ifdef CONFIG_CHECKPOINT_RESTORE +extern int export_encode_inode_fh (struct inode *inode,struct fid *fid,int *max_len); +#endif +extern int exportfs_encode_fh (struct dentry *dentry,struct fid *fid,int *max_len,int connectable); extern struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
PATCH 7/7 fs, notify: Add procfs fdinfo helper v3
In reply to Cyrill GorcunovThis allow us to print out fsnotify details such as watchee inode, device, mask and file handle.
For example for inotify objects the output is
| pos: 0 | flags: 02000000 | inotify wd: 3 ino: 9e7e sdev: 800013 mask: 800afce ignored_mask: 0 fhandle-bytes: 8 fhandle-type: 1 f_handle: 7e9e0000640d1b6d | inotify wd: 2 ino: a111 sdev: 800013 mask: 800afce ignored_mask: 0 fhandle-bytes: 8 fhandle-type: 1 f_handle: 11a1000020542153 | inotify wd: 1 ino: 6b149 sdev: 800013 mask: 800afce ignored_mask: 0 fhandle-bytes: 8 fhandle-type: 1 f_handle: 49b1060023552153
For fanotify it is like
| pos: 0 | flags: 02 | fanotify ino: 68f71 sdev: 800013 mask: 1 ignored_mask: 40000000 fhandle-bytes: 8 fhandle-type: 1 f_handle: 718f0600b9f42053 | fanotify mnt_id: 13 mask: 1 ignored_mask: 40000000
This feature is CONFIG_CHECKPOINT_RESTORE only. To minimize impact on general fsnotify code the new functionality is gathered in fs/notify/fdinfo.c file mostly.
v2:
- append missing colons to terms
v3:
- continue from pervious position in list on ->next
--- fs/notify/Makefile | 2 fs/notify/fanotify/fanotify_user.c | 17 ++ fs/notify/fdinfo.c | 216 +++++++++++++++++++++++++++++++++++++ fs/notify/fdinfo.h | 19 +++ fs/notify/inotify/inotify_user.c | 32 +++++ 5 files changed, 284 insertions(+), 2 deletions(-)
fs/notify/Makefile +1 -1
@@ -1,5 +1,5 @@ obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o \ - mark.o vfsmount_mark.o + mark.o vfsmount_mark.o fdinfo.o obj-y += dnotify/ obj-y += inotify/
fs/notify/fanotify/fanotify_user.c +16 -1
@@ -17,6 +17,7 @@#include <asm/ioctls.h> #include "../../mount.h" +#include "../fdinfo.h" #define FANOTIFY_DEFAULT_MAX_EVENTS 16384#define FANOTIFY_DEFAULT_MAX_MARKS 8192
@@ -877,6 +878,20 @@ asmlinkage long SyS_fanotify_mark(long fSYSCALL_ALIAS (sys_fanotify_mark, SyS_fanotify_mark);#endif +#if defined(CONFIG_PROC_FS ) && defined(CONFIG_CHECKPOINT_RESTORE ) +int is_file_fanotify (struct file *file) +{ +return file->f_op == &fanotify_fops; +} + +static int __init fanotify_register_fdinfo_driver (void ) +{ +return proc_register_fdinfo_driver (&fanotify_fdinfo); +} +#else +void fanotify_register_fdinfo_driver (void ) { } +#endif /* CONFIG_PROC_FS && CONFIG_CHECKPOINT_RESTORE */ +/* * fanotify_user_setup - Our initialization function. Note that we cannot return * error because we have compiled-in VFS hooks. So an (unlikely) failure here
@@ -887,7 +902,7 @@ static int __init fanotify_user_setup(vo fanotify_mark_cache =KMEM_CACHE (fsnotify_mark,SLAB_PANIC ); fanotify_response_event_cache =KMEM_CACHE (fanotify_response_event,SLAB_PANIC ); - +fanotify_register_fdinfo_driver ();return 0 ; }device_initcall (fanotify_user_setup);
fs/notify/fdinfo.c new file +216 -0
216 lines not on this page · raw message
fs/notify/fdinfo.h new file +19 -0
@@ -0,0 +1,19 @@ +#ifndef __FSNOTIFY_FDINFO_H__ +#define __FSNOTIFY_FDINFO_H__ + +#include <linux/errno.h> +#include <linux/proc_fs.h> + +#if defined(CONFIG_PROC_FS ) && defined(CONFIG_CHECKPOINT_RESTORE ) + +#ifdef CONFIG_INOTIFY_USER +extern struct proc_fdinfo_driver inotify_fdinfo; +#endif + +#ifdef CONFIG_FANOTIFY +extern struct proc_fdinfo_driver fanotify_fdinfo; +#endif + +#endif + +#endif /* __FSNOTIFY_FDINFO_H__ */
fs/notify/inotify/inotify_user.c +32 -0
@@ -38,8 +38,12 @@#include <linux/uaccess.h> #include <linux/poll.h> #include <linux/wait.h> +#include <linux/seq_file.h> +#include <linux/exportfs.h> +#include <linux/proc_fs.h> #include "inotify.h" +#include "../fdinfo.h" #include <asm/ioctls.h>
@@ -827,6 +831,26 @@ out:return ret; } +#if defined(CONFIG_PROC_FS ) && defined(CONFIG_CHECKPOINT_RESTORE ) +int is_file_inotify (struct file *file) +{ +return file->f_op == &inotify_fops; +} + +static int __init inotify_register_fdinfo_driver (void ) +{ +return proc_register_fdinfo_driver (&inotify_fdinfo); +} + +static void __exit inotify_unregister_fdinfo_driver(void) +{ +proc_unregister_fdinfo_driver (&inotify_fdinfo); +} +#else +static int __init inotify_register_fdinfo_driver (void ) {return 0 ; } +static void __exit inotify_unregister_fdinfo_driver(void) { } +#endif /* CONFIG_PROC_FS && CONFIG_CHECKPOINT_RESTORE */ +/* * inotify_user_setup - Our initialization function. Note that we cannot return * error because we have compiled-in VFS hooks. So an (unlikely) failure here
@@ -862,6 +886,14 @@ static int __init inotify_user_setup(voi inotify_max_user_instances =128 ; inotify_max_user_watches =8192 ; +inotify_register_fdinfo_driver (); +return 0 ; }module_init (inotify_user_setup); + +static void __exit inotify_user_exit(void) +{ +inotify_unregister_fdinfo_driver (); +} +module_exit (inotify_user_exit);