2008-06-07 01:24:43

by Chris Wright

[permalink] [raw]
Subject: [patch 42/50] proc: calculate the correct /proc/<pid> link count

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Vegard Nossum <[email protected]>

upstream commit: aed5417593ad125283f35513573282139a8664b5

This patch:

commit e9720acd728a46cb40daa52c99a979f7c4ff195c
Author: Pavel Emelyanov <[email protected]>
Date: Fri Mar 7 11:08:40 2008 -0800

[NET]: Make /proc/net a symlink on /proc/self/net (v3)

introduced a /proc/self/net directory without bumping the corresponding
link count for /proc/self.

This patch replaces the static link count initializations with a call that
counts the number of directory entries in the given pid_entry table
whenever it is instantiated, and thus relieves the burden of manually
keeping the two in sync.

[[email protected]: cleanup]
Acked-by: Eric W. Biederman <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Signed-off-by: Vegard Nossum <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
fs/proc/base.c | 33 +++++++++++++++++++++++++--------
1 file changed, 25 insertions(+), 8 deletions(-)

--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -126,6 +126,25 @@ struct pid_entry {
NULL, &proc_single_file_operations, \
{ .proc_show = &proc_##OTYPE } )

+/*
+ * Count the number of hardlinks for the pid_entry table, excluding the .
+ * and .. links.
+ */
+static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
+ unsigned int n)
+{
+ unsigned int i;
+ unsigned int count;
+
+ count = 0;
+ for (i = 0; i < n; ++i) {
+ if (S_ISDIR(entries[i].mode))
+ ++count;
+ }
+
+ return count;
+}
+
int maps_protect;
EXPORT_SYMBOL(maps_protect);

@@ -2483,10 +2502,9 @@ static struct dentry *proc_pid_instantia
inode->i_op = &proc_tgid_base_inode_operations;
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
- inode->i_nlink = 5;
-#ifdef CONFIG_SECURITY
- inode->i_nlink += 1;
-#endif
+
+ inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
+ ARRAY_SIZE(tgid_base_stuff));

dentry->d_op = &pid_dentry_operations;

@@ -2713,10 +2731,9 @@ static struct dentry *proc_task_instanti
inode->i_op = &proc_tid_base_inode_operations;
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
- inode->i_nlink = 4;
-#ifdef CONFIG_SECURITY
- inode->i_nlink += 1;
-#endif
+
+ inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
+ ARRAY_SIZE(tid_base_stuff));

dentry->d_op = &pid_dentry_operations;


--