[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>

1 files changed, 10 insertions, 7 deletions

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index effa6c0c467a..e6a818a93f3d 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -156,10 +156,13 @@ 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) {
                 if (de->mode) {
@@ -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)