Commit 99dc8292 authored by Jerome Marchand's avatar Jerome Marchand Committed by Linus Torvalds

procfs: fix numbering in /proc/locks

The lock number in /proc/locks (first field) is implemented by a counter
(private field of struct seq_file) which is incremented at each call of
locks_show() and reset to 1 in locks_start() whatever the offset is.  It
should be reset according to the actual position in the list.  Because of
this, the numbering erratically restarts at 1 several times when reading a
long /proc/locks file.

Moreover, locks_show() can be called twice to print a single line thus
skipping a number.  The counter should be incremented in locks_next().

And last, pos is a loff_t, which can be bigger than a pointer, so we don't
use the pointer as an integer anymore, and allocate a loff_t instead.
Signed-off-by: default avatarJerome Marchand <>
Cc: Pavel Emelyanov <>
Cc: Matthew Wilcox <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 4199ca77
......@@ -2109,7 +2109,7 @@ EXPORT_SYMBOL_GPL(vfs_cancel_lock);
#include <linux/seq_file.h>
static void lock_get_status(struct seq_file *f, struct file_lock *fl,
int id, char *pfx)
loff_t id, char *pfx)
struct inode *inode = NULL;
unsigned int fl_pid;
......@@ -2122,7 +2122,7 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
if (fl->fl_file != NULL)
inode = fl->fl_file->f_path.dentry->d_inode;
seq_printf(f, "%d:%s ", id, pfx);
seq_printf(f, "%lld:%s ", id, pfx);
if (IS_POSIX(fl)) {
seq_printf(f, "%6s %s ",
(fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
......@@ -2185,24 +2185,27 @@ static int locks_show(struct seq_file *f, void *v)
fl = list_entry(v, struct file_lock, fl_link);
lock_get_status(f, fl, (long)f->private, "");
lock_get_status(f, fl, *((loff_t *)f->private), "");
list_for_each_entry(bfl, &fl->fl_block, fl_block)
lock_get_status(f, bfl, (long)f->private, " ->");
lock_get_status(f, bfl, *((loff_t *)f->private), " ->");
return 0;
static void *locks_start(struct seq_file *f, loff_t *pos)
loff_t *p = f->private;
f->private = (void *)1;
*p = (*pos + 1);
return seq_list_start(&file_lock_list, *pos);
static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
loff_t *p = f->private;
return seq_list_next(v, &file_lock_list, pos);
......@@ -2220,14 +2223,14 @@ static const struct seq_operations locks_seq_operations = {
static int locks_open(struct inode *inode, struct file *filp)
return seq_open(filp, &locks_seq_operations);
return seq_open_private(filp, &locks_seq_operations, sizeof(loff_t));
static const struct file_operations proc_locks_operations = {
.open = locks_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
.release = seq_release_private,
static int __init proc_locks_init(void)
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