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.
---

From: Sukadev Bhattiprolu <sukadev@us.ibm.com>

Subject: Replace pid_t in autofs with struct pid reference.

Make autofs container-friendly by caching struct pid reference rather
than pid_t.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: containers@lists.osdl.org

---
 fs/autofs/autofs_i.h |    4 ++--
 fs/autofs/inode.c    |   33 ++++++++++++++++++++++++---------
 fs/autofs/root.c     |    6 ++++--
 3 files changed, 30 insertions(+), 13 deletions(-)

Index: lx26-20-rc4-mm1/fs/autofs/autofs_i.h
===================================================================
--- lx26-20-rc4-mm1.orig/fs/autofs/autofs_i.h	2007-01-24 17:29:32.471909792 -0800
+++ lx26-20-rc4-mm1/fs/autofs/autofs_i.h	2007-01-24 17:31:10.277041152 -0800
@@ -101,7 +101,7 @@ struct autofs_symlink {
 struct autofs_sb_info {
 	u32 magic;
 	struct file *pipe;
-	pid_t oz_pgrp;
+	struct pid *oz_pgrp;
 	int catatonic;
 	struct super_block *sb;
 	unsigned long exp_timeout;
@@ -122,7 +122,7 @@ static inline struct autofs_sb_info *aut
    filesystem without "magic".) */
 
 static inline int autofs_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;
 }
 
 /* Hash operations */
Index: lx26-20-rc4-mm1/fs/autofs/inode.c
===================================================================
--- lx26-20-rc4-mm1.orig/fs/autofs/inode.c	2007-01-24 17:29:32.471909792 -0800
+++ lx26-20-rc4-mm1/fs/autofs/inode.c	2007-01-24 18:39:20.834181944 -0800
@@ -37,6 +37,8 @@ void autofs_kill_sb(struct super_block *
 	if ( !sbi->catatonic )
 		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
 
+	put_pid(sbi->oz_pgrp);
+
 	autofs_hash_nuke(sbi);
 	for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
 		if ( test_bit(n, sbi->symlink_bitmap) )
@@ -69,15 +71,17 @@ static match_table_t autofs_tokens = {
 	{Opt_err, NULL}
 };
 
-static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
+static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
+		struct pid **pgrp, int *minproto, int *maxproto)
 {
 	char *p;
 	substring_t args[MAX_OPT_ARGS];
 	int option;
+	pid_t pgid;
 
 	*uid = current->uid;
 	*gid = current->gid;
-	*pgrp = process_group(current);
+	pgid = process_group(current);
 
 	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
 
@@ -111,7 +115,7 @@ static int parse_options(char *options, 
 		case Opt_pgrp:
 			if (match_int(&args[0], &option))
 				return 1;
-			*pgrp = option;
+			pgid = option;
 			break;
 		case Opt_minproto:
 			if (match_int(&args[0], &option))
@@ -127,7 +131,13 @@ static int parse_options(char *options, 
 			return 1;
 		}
 	}
-	return (*pipefd < 0);
+
+	if (*pipefd < 0)
+		return 1;
+
+	*pgrp = find_get_pid(pgid);
+
+	return (*pgrp == NULL);
 }
 
 int autofs_fill_super(struct super_block *s, void *data, int silent)
@@ -149,7 +159,7 @@ int autofs_fill_super(struct super_block
 	sbi->pipe = NULL;
 	sbi->catatonic = 1;
 	sbi->exp_timeout = 0;
-	sbi->oz_pgrp = process_group(current);
+	sbi->oz_pgrp = NULL;
 	autofs_initialize_hash(&sbi->dirhash);
 	sbi->queues = NULL;
 	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
@@ -169,7 +179,9 @@ int autofs_fill_super(struct super_block
 		goto fail_iput;
 
 	/* Can this call block?  - WTF cares? s is locked. */
-	if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
+	if ( parse_options(data, &pipefd, &root_inode->i_uid,
+				&root_inode->i_gid, &sbi->oz_pgrp, &minproto,
+				&maxproto) ) {
 		printk("autofs: called with bogus options\n");
 		goto fail_dput;
 	}
@@ -178,15 +190,16 @@ int autofs_fill_super(struct super_block
 	if ( minproto > AUTOFS_PROTO_VERSION || 
 	     maxproto < AUTOFS_PROTO_VERSION ) {
 		printk("autofs: kernel does not match daemon version\n");
-		goto fail_dput;
+		goto fail_put_pid;
 	}
 
-	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
+	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd,
+				pid_nr(sbi->oz_pgrp)));
 	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;
@@ -202,6 +215,8 @@ int autofs_fill_super(struct super_block
 fail_fput:
 	printk("autofs: pipe file descriptor does not contain proper ops\n");
 	fput(pipe);
+fail_put_pid:
+	put_pid(sbi->oz_pgrp);
 fail_dput:
 	dput(root);
 	goto fail_free;
Index: lx26-20-rc4-mm1/fs/autofs/root.c
===================================================================
--- lx26-20-rc4-mm1.orig/fs/autofs/root.c	2007-01-24 17:29:32.471909792 -0800
+++ lx26-20-rc4-mm1/fs/autofs/root.c	2007-01-24 18:39:20.834181944 -0800
@@ -213,8 +213,10 @@ static struct dentry *autofs_root_lookup
 	sbi = autofs_sbi(dir->i_sb);
 
 	oz_mode = autofs_oz_mode(sbi);
-	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
-		 current->pid, process_group(current), sbi->catatonic, oz_mode));
+	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
+				"oz_mode = %d\n", pid_nr(task_pid(current)),
+				process_group(current), sbi->catatonic,
+				oz_mode));
 
 	/*
 	 * Mark the dentry incomplete, but add it. This is needed so
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comments below,

Sukadev Bhattiprolu wrote:
> 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.
> ---
> 
> From: Sukadev Bhattiprolu <sukadev@us.ibm.com>
> 
> Subject: Replace pid_t in autofs with struct pid reference.
> 
> Make autofs container-friendly by caching struct pid reference rather
> than pid_t.
> 
> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
> Cc: Cedric Le Goater <clg@fr.ibm.com>
> Cc: Dave Hansen <haveblue@us.ibm.com>
> Cc: Serge Hallyn <serue@us.ibm.com>
> Cc: Eric Biederman <ebiederm@xmission.com>
> Cc: containers@lists.osdl.org
> 
> ---
>  fs/autofs/autofs_i.h |    4 ++--
>  fs/autofs/inode.c    |   33 ++++++++++++++++++++++++---------
>  fs/autofs/root.c     |    6 ++++--
>  3 files changed, 30 insertions(+), 13 deletions(-)
> 
> Index: lx26-20-rc4-mm1/fs/autofs/autofs_i.h
> ===================================================================
> --- lx26-20-rc4-mm1.orig/fs/autofs/autofs_i.h	2007-01-24 17:29:32.471909792 -0800
> +++ lx26-20-rc4-mm1/fs/autofs/autofs_i.h	2007-01-24 17:31:10.277041152 -0800
> @@ -101,7 +101,7 @@ struct autofs_symlink {
>  struct autofs_sb_info {
>  	u32 magic;
>  	struct file *pipe;
> -	pid_t oz_pgrp;
> +	struct pid *oz_pgrp;
>  	int catatonic;
>  	struct super_block *sb;
>  	unsigned long exp_timeout;
> @@ -122,7 +122,7 @@ static inline struct autofs_sb_info *aut
>     filesystem without "magic".) */
>  
>  static inline int autofs_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;
>  }
>  
>  /* Hash operations */
> Index: lx26-20-rc4-mm1/fs/autofs/inode.c
> ===================================================================
> --- lx26-20-rc4-mm1.orig/fs/autofs/inode.c	2007-01-24 17:29:32.471909792 -0800
> +++ lx26-20-rc4-mm1/fs/autofs/inode.c	2007-01-24 18:39:20.834181944 -0800
> @@ -37,6 +37,8 @@ void autofs_kill_sb(struct super_block *
>  	if ( !sbi->catatonic )
>  		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
>  
> +	put_pid(sbi->oz_pgrp);
> +
>  	autofs_hash_nuke(sbi);
>  	for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
>  		if ( test_bit(n, sbi->symlink_bitmap) )

too many white spaces. may be you could fix those at the same time ?

> @@ -69,15 +71,17 @@ static match_table_t autofs_tokens = {
>  	{Opt_err, NULL}
>  };
>  
> -static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, pid_t *pgrp, int *minproto, int *maxproto)
> +static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
> +		struct pid **pgrp, int *minproto, int *maxproto)
>  {
>  	char *p;
>  	substring_t args[MAX_OPT_ARGS];
>  	int option;
> +	pid_t pgid;
>  
>  	*uid = current->uid;
>  	*gid = current->gid;
> -	*pgrp = process_group(current);
> +	pgid = process_group(current);
>  
>  	*minproto = *maxproto = AUTOFS_PROTO_VERSION;
>  
> @@ -111,7 +115,7 @@ static int parse_options(char *options, 
>  		case Opt_pgrp:
>  			if (match_int(&args[0], &option))
>  				return 1;
> -			*pgrp = option;
> +			pgid = option;
>  			break;
>  		case Opt_minproto:
>  			if (match_int(&args[0], &option))
> @@ -127,7 +131,13 @@ static int parse_options(char *options, 
>  			return 1;
>  		}
>  	}
> -	return (*pipefd < 0);
> +
> +	if (*pipefd < 0)
> +		return 1;
> +
> +	*pgrp = find_get_pid(pgid);
> +
> +	return (*pgrp == NULL);
>  }
>  
>  int autofs_fill_super(struct super_block *s, void *data, int silent)
> @@ -149,7 +159,7 @@ int autofs_fill_super(struct super_block
>  	sbi->pipe = NULL;
>  	sbi->catatonic = 1;
>  	sbi->exp_timeout = 0;
> -	sbi->oz_pgrp = process_group(current);
> +	sbi->oz_pgrp = NULL;
>  	autofs_initialize_hash(&sbi->dirhash);
>  	sbi->queues = NULL;
>  	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
> @@ -169,7 +179,9 @@ int autofs_fill_super(struct super_block
>  		goto fail_iput;
>  
>  	/* Can this call block?  - WTF cares? s is locked. */
> -	if ( parse_options(data,&pipefd,&root_inode->i_uid,&root_inode->i_gid,&sbi->oz_pgrp,&minproto,&maxproto) ) {
> +	if ( parse_options(data, &pipefd, &root_inode->i_uid,
> +				&root_inode->i_gid, &sbi->oz_pgrp, &minproto,
> +				&maxproto) ) {

I would keep the old prototype of parse_options

>  		printk("autofs: called with bogus options\n");
>  		goto fail_dput;
>  	}

and do the find_get_pid() here. it looks simpler for me.

> @@ -178,15 +190,16 @@ int autofs_fill_super(struct super_block
>  	if ( minproto > AUTOFS_PROTO_VERSION || 
>  	     maxproto < AUTOFS_PROTO_VERSION ) {
>  		printk("autofs: kernel does not match daemon version\n");
> -		goto fail_dput;
> +		goto fail_put_pid;
>  	}
>  
> -	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
> +	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd,
> +				pid_nr(sbi->oz_pgrp)));
>  	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;
> @@ -202,6 +215,8 @@ int autofs_fill_super(struct super_block
>  fail_fput:
>  	printk("autofs: pipe file descriptor does not contain proper ops\n");
>  	fput(pipe);
> +fail_put_pid:
> +	put_pid(sbi->oz_pgrp);
>  fail_dput:
>  	dput(root);
>  	goto fail_free;
> Index: lx26-20-rc4-mm1/fs/autofs/root.c
> ===================================================================
> --- lx26-20-rc4-mm1.orig/fs/autofs/root.c	2007-01-24 17:29:32.471909792 -0800
> +++ lx26-20-rc4-mm1/fs/autofs/root.c	2007-01-24 18:39:20.834181944 -0800
> @@ -213,8 +213,10 @@ static struct dentry *autofs_root_lookup
>  	sbi = autofs_sbi(dir->i_sb);
>  
>  	oz_mode = autofs_oz_mode(sbi);
> -	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
> -		 current->pid, process_group(current), sbi->catatonic, oz_mode));
> +	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
> +				"oz_mode = %d\n", pid_nr(task_pid(current)),
> +				process_group(current), sbi->catatonic,
> +				oz_mode));


you can keep current->pid I think

>  	/*
>  	 * Mark the dentry incomplete, but add it. This is needed so
> _______________________________________________
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> Containers@lists.osdl.org
> https://lists.osdl.org/mailman/listinfo/containers
> 

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Cedric Le Goater [clg@fr.ibm.com] wrote:
| comments below,
| 
| >  	autofs_hash_nuke(sbi);
| >  	for ( n = 0 ; n < AUTOFS_MAX_SYMLINKS ; n++ ) {
| >  		if ( test_bit(n, sbi->symlink_bitmap) )
| 
| too many white spaces. may be you could fix those at the same time ?

There are too many of those errors in the autofs/autofs4 files. I am
moving all those changes to a separate patch so the main patch stays
small. Let me know if thats a bad idea.

| > +	if ( parse_options(data, &pipefd, &root_inode->i_uid,
| > +				&root_inode->i_gid, &sbi->oz_pgrp, &minproto,
| > +				&maxproto) ) {
| 
| I would keep the old prototype of parse_options
| 
| >  		printk("autofs: called with bogus options\n");
| >  		goto fail_dput;
| >  	}
| 
| and do the find_get_pid() here. it looks simpler for me.

Agree.

| > +	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, "
| > +				"oz_mode = %d\n", pid_nr(task_pid(current)),
| > +				process_group(current), sbi->catatonic,
| > +				oz_mode));
| 
| 
| you can keep current->pid I think
| 

I am not sure. If a process unshares its pid-ns and then used to automount
in the child ns, won't we print the wrong pid ?

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