From: J. Bruce Fields Date: Fri, 29 Jun 2012 20:20:47 +0000 (-0400) Subject: dcache: Don't set DISCONNECTED on "pseudo filesystem" dentries X-Git-Tag: v3.13-rc1~107^2~23 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=e1a24bb0aa6abaa86b5a95638722ea2036dbaadd;p=uclinux-h8%2Flinux.git dcache: Don't set DISCONNECTED on "pseudo filesystem" dentries 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 4b936885ab04dc6e0bb0ef35e0e23c1a7364d9e5 "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 Acked-by: Christoph Hellwig Signed-off-by: J. Bruce Fields Signed-off-by: Al Viro --- diff --git a/fs/dcache.c b/fs/dcache.c index c2add37082b6..67662beebc72 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -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);