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

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 <jmarchan@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4199ca77

fs/locks.c

+11 −8
Original line number Diff line number Diff line
@@ -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), " ->");



	f->private++;

	return 0;

}



static void *locks_start(struct seq_file *f, loff_t *pos)

{

	loff_t *p = f->private;



	lock_flocks();

	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;

	++*p;

	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)

CRA Git | Maintained and supported by SUSTech CRA and CCSE