Commit c663e5d8 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds

[PATCH] add some comments to lookup_create()

In a duplicate of lookup_create in the af_unix code Al commented what's
going on nicely, so let's bring that over to lookup_create before the copy
is going away (I'll send a patch soon)
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 70f09f1f
......@@ -1577,19 +1577,35 @@ do_link:
*
* Simple function to lookup and return a dentry and create it
* if it doesn't exist. Is SMP-safe.
*
* Returns with nd->dentry->d_inode->i_sem locked.
*/
struct dentry *lookup_create(struct nameidata *nd, int is_dir)
{
struct dentry *dentry;
struct dentry *dentry = ERR_PTR(-EEXIST);
down(&nd->dentry->d_inode->i_sem);
dentry = ERR_PTR(-EEXIST);
/*
* Yucky last component or no last component at all?
* (foo/., foo/.., /////)
*/
if (nd->last_type != LAST_NORM)
goto fail;
nd->flags &= ~LOOKUP_PARENT;
/*
* Do the final lookup.
*/
dentry = lookup_hash(&nd->last, nd->dentry);
if (IS_ERR(dentry))
goto fail;
/*
* Special case - lookup gave negative, but... we had foo/bar/
* From the vfs_mknod() POV we just have a negative dentry -
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode)
goto enoent;
return dentry;
......
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