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dcache: Don't set DISCONNECTED on "pseudo filesystem" dentries

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I can't for the life of me see any reason why anyone should care whether
a dentry that is never hooked into the dentry cache would need
DCACHE_DISCONNECTED set.

This originates from 4b936885ab "fs:
improve scalability of pseudo filesystems", which probably just made the
false assumption the DCACHE_DISCONNECTED was meant to be set on anything
not connected to a parent somehow.

So this is just confusing.  Ideally the only uses of DCACHE_DISCONNECTED
would be in the filehandle-lookup code, which needs it to ensure
dentries are connected into the dentry tree before use.

I left d_alloc_pseudo there even though it's now equivalent to
__d_alloc(), just on the theory the name is better documentation of its
intended use outside dcache.c.

Cc: Nick Piggin <npiggin@kernel.dk>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
J. Bruce Fields 2012-06-29 16:20:47 -04:00 committed by Al Viro
parent 7632e465fe
commit e1a24bb0aa
1 changed files with 9 additions and 4 deletions
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13
fs/dcache.c
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@ -1607,12 +1607,17 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
}
EXPORT_SYMBOL(d_alloc);
/**
* d_alloc_pseudo - allocate a dentry (for lookup-less filesystems)
* @sb: the superblock
* @name: qstr of the name
*
* For a filesystem that just pins its dentries in memory and never
* performs lookups at all, return an unhashed IS_ROOT dentry.
*/
struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
{
struct dentry *dentry = __d_alloc(sb, name);
if (dentry)
dentry->d_flags |= DCACHE_DISCONNECTED;
return dentry;
return __d_alloc(sb, name);
}
EXPORT_SYMBOL(d_alloc_pseudo);