Re: [PATCH 2/2] Replace pid_t in autofs with struct pid reference
From: Cedric Le Goater
Date: Fri Mar 16 2007 - 10:44:59 EST
> How about you send over the autofs4 bit and I'll have a look (the autofs
> patch looked fine). That would save me a bit of time and if there are
> any changes needed I can send an updated patch for you guys to review. I
> don't think autofs4 uses pids differently, in principle, than autofs so
> it "should" be straight forward.
Here's the latest.
thanks,
C.
From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx>
Subject: Replace pid_t in autofs4 with struct pid reference.
Make autofs4 container-friendly by caching struct pid reference rather
than pid_t and using pid_nr() to retreive a task's pid_t.
ChangeLog:
- Fix Eric Biederman's comments - Use find_get_pid() to hold a
reference to oz_pgrp and release while unmounting; separate out
changes to autofs and autofs4.
- Also rollback my earlier change to autofs_wait_queue (pid and tgid
in the wait queue are just used to write to a userspace daemon's
pipe).
- Fix Cedric's comments: retain old prototype of parse_options()
and move necessary change to its caller.
Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx>
Cc: Cedric Le Goater <clg@xxxxxxxxxx>
Cc: Dave Hansen <haveblue@xxxxxxxxxx>
Cc: Serge Hallyn <serue@xxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: containers@xxxxxxxxxxxxxx
---
fs/autofs4/autofs_i.h | 6 +++---
fs/autofs4/inode.c | 21 ++++++++++++++++-----
fs/autofs4/root.c | 3 ++-
fs/autofs4/waitq.c | 4 ++--
4 files changed, 23 insertions(+), 11 deletions(-)
Index: 2.6.20/fs/autofs4/autofs_i.h
===================================================================
--- 2.6.20.orig/fs/autofs4/autofs_i.h
+++ 2.6.20/fs/autofs4/autofs_i.h
@@ -35,7 +35,7 @@
/* #define DEBUG */
#ifdef DEBUG
-#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0)
+#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , pid_nr(task_pid(current)), __FUNCTION__ , ##args); } while(0)
#else
#define DPRINTK(fmt,args...) do {} while(0)
#endif
@@ -96,7 +96,7 @@ struct autofs_sb_info {
u32 magic;
int pipefd;
struct file *pipe;
- pid_t oz_pgrp;
+ struct pid *oz_pgrp;
int catatonic;
int version;
int sub_version;
@@ -127,7 +127,7 @@ static inline struct autofs_info *autofs
filesystem without "magic".) */
static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) {
- return sbi->catatonic || process_group(current) == sbi->oz_pgrp;
+ return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
}
/* Does a dentry have some pending activity? */
Index: 2.6.20/fs/autofs4/inode.c
===================================================================
--- 2.6.20.orig/fs/autofs4/inode.c
+++ 2.6.20/fs/autofs4/inode.c
@@ -163,6 +163,8 @@ void autofs4_kill_sb(struct super_block
if ( !sbi->catatonic )
autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
+ put_pid(sbi->oz_pgrp);
+
/* Clean up and release dangling references */
autofs4_force_release(sbi);
@@ -181,7 +183,7 @@ static int autofs4_show_options(struct s
return 0;
seq_printf(m, ",fd=%d", sbi->pipefd);
- seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
+ seq_printf(m, ",pgrp=%d", pid_nr(sbi->oz_pgrp));
seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
seq_printf(m, ",minproto=%d", sbi->min_proto);
seq_printf(m, ",maxproto=%d", sbi->max_proto);
@@ -311,6 +313,7 @@ int autofs4_fill_super(struct super_bloc
int pipefd;
struct autofs_sb_info *sbi;
struct autofs_info *ino;
+ pid_t pgid;
sbi = kmalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
@@ -325,7 +328,6 @@ int autofs4_fill_super(struct super_bloc
sbi->pipe = NULL;
sbi->catatonic = 1;
sbi->exp_timeout = 0;
- sbi->oz_pgrp = process_group(current);
sbi->sb = s;
sbi->version = 0;
sbi->sub_version = 0;
@@ -361,7 +363,7 @@ int autofs4_fill_super(struct super_bloc
/* Can this call block? */
if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
- &sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
+ &pgid, &sbi->type, &sbi->min_proto,
&sbi->max_proto)) {
printk("autofs: called with bogus options\n");
goto fail_dput;
@@ -389,12 +391,19 @@ int autofs4_fill_super(struct super_bloc
sbi->version = sbi->max_proto;
sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
- DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
+ DPRINTK("pipe fd = %d, pgrp = %u", pipefd, pgid);
+
+ sbi->oz_pgrp = find_get_pid(pgid);
+ if (!sbi->oz_pgrp) {
+ printk("autofs: could not find process group %d\n", pgid);
+ goto fail_dput;
+ }
+
pipe = fget(pipefd);
if (!pipe) {
printk("autofs: could not open pipe file descriptor\n");
- goto fail_dput;
+ goto fail_put_pid;
}
if (!pipe->f_op || !pipe->f_op->write)
goto fail_fput;
@@ -415,6 +424,8 @@ fail_fput:
printk("autofs: pipe file descriptor does not contain proper ops\n");
fput(pipe);
/* fall through */
+fail_put_pid:
+ put_pid(sbi->oz_pgrp);
fail_dput:
dput(root);
goto fail_free;
Index: 2.6.20/fs/autofs4/root.c
===================================================================
--- 2.6.20.orig/fs/autofs4/root.c
+++ 2.6.20/fs/autofs4/root.c
@@ -495,7 +495,8 @@ static struct dentry *autofs4_lookup(str
oz_mode = autofs4_oz_mode(sbi);
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
- current->pid, process_group(current), sbi->catatonic, oz_mode);
+ pid_nr(task_pid(current)), process_group(current),
+ sbi->catatonic, oz_mode);
/*
* Mark the dentry incomplete, but add it. This is needed so
Index: 2.6.20/fs/autofs4/waitq.c
===================================================================
--- 2.6.20.orig/fs/autofs4/waitq.c
+++ 2.6.20/fs/autofs4/waitq.c
@@ -292,8 +292,8 @@ int autofs4_wait(struct autofs_sb_info *
wq->ino = autofs4_get_ino(sbi);
wq->uid = current->uid;
wq->gid = current->gid;
- wq->pid = current->pid;
- wq->tgid = current->tgid;
+ wq->pid = pid_nr(task_pid(current));
+ wq->tgid = pid_nr(task_tgid(current));
wq->status = -EINTR; /* Status return if interrupted */
atomic_set(&wq->wait_ctr, 2);
mutex_unlock(&sbi->wq_mutex);
-
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