Commit fa0334f1 authored by Sukadev Bhattiprolu's avatar Sukadev Bhattiprolu Committed by Linus Torvalds
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Replace pid_t in autofs with struct pid reference 



Make autofs 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.
	- Fix Cedric's comments: retain old prototype of parse_options()
	  and move necessary change to its caller.

Signed-off-by: default avatarSukadev 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
Acked-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d78e53c8

fs/autofs/autofs_i.h

+2 −2
Original line number Diff line number Diff line
@@ -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 *autofs_sbi(struct super_block *sb) 
   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 */

fs/autofs/inode.c

+16 −4
Original line number Diff line number Diff line
@@ -37,6 +37,8 @@ void autofs_kill_sb(struct super_block *sb) 
	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))
@@ -139,6 +141,7 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) 
	int pipefd;

	struct autofs_sb_info *sbi;

	int minproto, maxproto;

	pid_t pgid;



	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);

	if (!sbi)
@@ -150,7 +153,6 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) 
	sbi->pipe = NULL;

	sbi->catatonic = 1;

	sbi->exp_timeout = 0;

	sbi->oz_pgrp = process_group(current);

	autofs_initialize_hash(&sbi->dirhash);

	sbi->queues = NULL;

	memset(sbi->symlink_bitmap, 0, sizeof(long)*AUTOFS_SYMLINK_BITMAP_LEN);
@@ -171,7 +173,7 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) 


	/* 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,

				&root_inode->i_gid, &pgid, &minproto,

				&maxproto)) {

		printk("autofs: called with bogus options\n");

		goto fail_dput;
@@ -184,13 +186,21 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) 
		goto fail_dput;

	}



	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));

	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", 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;

	sbi->pipe = pipe;
@@ -205,6 +215,8 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) 
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;

fs/autofs/root.c

+4 −2
Original line number Diff line number Diff line
@@ -213,8 +213,10 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr 
	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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