functionfs: unfuck failure exits on mount

* if you do dput() of root dentry, do *not* follow that with iput() of root
inode.
* while we are at it, don't do that dput() at all - you are leaving the pointer
in ->s_root and your ->kill_sb() will be very unhappy with that.  It will do
proper dput(), though, so the easiest way is to leave that to it entirely.
* freeing ->s_fs_info is also best left to ->kill_sb() (which will do it
anyway), especially since we leave the pointer in place.
* that xchg() in ->kill_sb() is not a bug per se, but it's a plain and simple
masturbation with fewer excuses than Onan had...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-01-08 15:38:27 -05:00
Родитель 48fa57ac2c
Коммит 5b5f956035
1 изменённых файлов: 11 добавлений и 20 удалений

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@ -1037,7 +1037,6 @@ static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
{
struct ffs_sb_fill_data *data = _data;
struct inode *inode;
struct dentry *d;
struct ffs_data *ffs;
ENTER();
@ -1045,7 +1044,7 @@ static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
/* Initialise data */
ffs = ffs_data_new();
if (unlikely(!ffs))
goto enomem0;
goto Enomem;
ffs->sb = sb;
ffs->dev_name = data->dev_name;
@ -1065,26 +1064,21 @@ static int ffs_sb_fill(struct super_block *sb, void *_data, int silent)
&simple_dir_inode_operations,
&data->perms);
if (unlikely(!inode))
goto enomem1;
d = d_alloc_root(inode);
if (unlikely(!d))
goto enomem2;
sb->s_root = d;
goto Enomem;
sb->s_root = d_alloc_root(inode);
if (unlikely(!sb->s_root)) {
iput(inode);
goto Enomem;
}
/* EP0 file */
if (unlikely(!ffs_sb_create_file(sb, "ep0", ffs,
&ffs_ep0_operations, NULL)))
goto enomem3;
goto Enomem;
return 0;
enomem3:
dput(d);
enomem2:
iput(inode);
enomem1:
ffs_data_put(ffs);
enomem0:
Enomem:
return -ENOMEM;
}
@ -1196,14 +1190,11 @@ ffs_fs_mount(struct file_system_type *t, int flags,
static void
ffs_fs_kill_sb(struct super_block *sb)
{
void *ptr;
ENTER();
kill_litter_super(sb);
ptr = xchg(&sb->s_fs_info, NULL);
if (ptr)
ffs_data_put(ptr);
if (sb->s_fs_info)
ffs_data_put(sb->s_fs_info);
}
static struct file_system_type ffs_fs_type = {