Commit 899fc1a4 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Theodore Ts'o
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ext4: fix #11321: create /proc/ext4/*/stats more carefully 

ext4 creates per-suberblock directory in /proc/ext4/ . Name used as
basis is taken from bdevname, which, surprise, can contain slash.

However, proc while allowing to use proc_create("a/b", parent) form of
PDE creation, assumes that parent/a was already created.

bdevname in question is 'cciss/c0d0p9', directory is not created and all
this stuff goes directly into /proc (which is real bug).

Warning comes when _second_ partition is mounted.

http://bugzilla.kernel.org/show_bug.cgi?id=11321



Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent c62a11fd

fs/ext4/mballoc.c

+13 −3
Original line number Diff line number Diff line
@@ -2786,14 +2786,20 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb) 
	mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct proc_dir_entry *proc;

	char devname[64];

	char devname[BDEVNAME_SIZE], *p;



	if (proc_root_ext4 == NULL) {

		sbi->s_mb_proc = NULL;

		return -EINVAL;

	}

	bdevname(sb->s_bdev, devname);

	p = devname;

	while ((p = strchr(p, '/')))

		*p = '!';



	sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);

	if (!sbi->s_mb_proc)

		goto err_create_dir;



	MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);

	MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
@@ -2805,7 +2811,6 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb) 
	return 0;



err_out:

	printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);

	remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);

	remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);

	remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
@@ -2814,6 +2819,8 @@ err_out: 
	remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);

	remove_proc_entry(devname, proc_root_ext4);

	sbi->s_mb_proc = NULL;

err_create_dir:

	printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);



	return -ENOMEM;

}
@@ -2821,12 +2828,15 @@ err_out: 
static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	char devname[64];

	char devname[BDEVNAME_SIZE], *p;



	if (sbi->s_mb_proc == NULL)

		return -EINVAL;



	bdevname(sb->s_bdev, devname);

	p = devname;

	while ((p = strchr(p, '/')))

		*p = '!';

	remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);

	remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);

	remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);

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