Commit e9543659 authored Oct 30, 2005 by Kirill Korotaev Committed by Linus Torvalds Oct 30, 2005

[PATCH] proc: fix of error path in proc_get_inode()



This patch fixes incorrect error path in proc_get_inode(), when module
can't be get due to being unloaded.  When try_module_get() fails, this
function puts de(!) and still returns inode with non-getted de.

There are still unresolved known bugs in proc yet to be fixed:
- proc_dir_entry tree is managed without any serialization
- create_proc_entry() doesn't setup de->owner anyhow,
   so setting it later manually is inatomic.
- looks like almost all modules do not care whether
   it's de->owner is set...

Signed-Off-By: Denis Lunev <den@sw.ru>
Signed-Off-By: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent f12ec440

fs/proc/inode.c

+10 −7

Original line number	Diff line number	Diff line
		@@ -156,9 +156,12 @@ struct inode proc_get_inode(struct super_block sb, unsigned int ino,

		WARN_ON(de && de->deleted);

		if (de != NULL && !try_module_get(de->owner))
		goto out_mod;

		inode = iget(sb, ino);
		if (!inode)
		goto out_fail;
		goto out_ino;

		PROC_I(inode)->pde = de;
		if (de) {
		@@ -171,20 +174,20 @@ struct inode proc_get_inode(struct super_block sb, unsigned int ino,
		inode->i_size = de->size;
		if (de->nlink)
		inode->i_nlink = de->nlink;
		if (!try_module_get(de->owner))
		goto out_fail;
		if (de->proc_iops)
		inode->i_op = de->proc_iops;
		if (de->proc_fops)
		inode->i_fop = de->proc_fops;
		}

		out:
		return inode;

		out_fail:
		out_ino:
		if (de != NULL)
		module_put(de->owner);
		out_mod:
		de_put(de);
		goto out;
		return NULL;
		}

		int proc_fill_super(struct super_block s, void data, int silent)