Commit 899fc1a4 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Theodore Ts'o

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=11321Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent c62a11fd
......@@ -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 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb)
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 @@ static int ext4_mb_init_per_dev_proc(struct super_block *sb)
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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