X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=fs%2Fdcache.c;h=d30ce699ae4b6ea4ac3ad1b8ec955fa271bdcb16;hb=3e0629cb6c0518423c9e2671bbe8ec15dde5dcaf;hp=3ed09536399735528f0992b4be98a2610651b61c;hpb=da093a9b76efca0a7a217af538929e1ecb204466;p=cascardo%2Flinux.git diff --git a/fs/dcache.c b/fs/dcache.c index 3ed095363997..d30ce699ae4b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -731,8 +731,6 @@ EXPORT_SYMBOL(dget_parent); /** * d_find_alias - grab a hashed alias of inode * @inode: inode in question - * @want_discon: flag, used by d_splice_alias, to request - * that only a DISCONNECTED alias be returned. * * If inode has a hashed alias, or is a directory and has any alias, * acquire the reference to alias and return it. Otherwise return NULL. @@ -741,10 +739,9 @@ EXPORT_SYMBOL(dget_parent); * of a filesystem. * * If the inode has an IS_ROOT, DCACHE_DISCONNECTED alias, then prefer - * any other hashed alias over that one unless @want_discon is set, - * in which case only return an IS_ROOT, DCACHE_DISCONNECTED alias. + * any other hashed alias over that one. */ -static struct dentry *__d_find_alias(struct inode *inode, int want_discon) +static struct dentry *__d_find_alias(struct inode *inode) { struct dentry *alias, *discon_alias; @@ -756,7 +753,7 @@ again: if (IS_ROOT(alias) && (alias->d_flags & DCACHE_DISCONNECTED)) { discon_alias = alias; - } else if (!want_discon) { + } else { __dget_dlock(alias); spin_unlock(&alias->d_lock); return alias; @@ -768,12 +765,9 @@ again: alias = discon_alias; spin_lock(&alias->d_lock); if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { - if (IS_ROOT(alias) && - (alias->d_flags & DCACHE_DISCONNECTED)) { - __dget_dlock(alias); - spin_unlock(&alias->d_lock); - return alias; - } + __dget_dlock(alias); + spin_unlock(&alias->d_lock); + return alias; } spin_unlock(&alias->d_lock); goto again; @@ -787,7 +781,7 @@ struct dentry *d_find_alias(struct inode *inode) if (!hlist_empty(&inode->i_dentry)) { spin_lock(&inode->i_lock); - de = __d_find_alias(inode, 0); + de = __d_find_alias(inode); spin_unlock(&inode->i_lock); } return de; @@ -1781,25 +1775,7 @@ struct dentry *d_find_any_alias(struct inode *inode) } EXPORT_SYMBOL(d_find_any_alias); -/** - * d_obtain_alias - find or allocate a dentry for a given inode - * @inode: inode to allocate the dentry for - * - * Obtain a dentry for an inode resulting from NFS filehandle conversion or - * similar open by handle operations. The returned dentry may be anonymous, - * or may have a full name (if the inode was already in the cache). - * - * When called on a directory inode, we must ensure that the inode only ever - * has one dentry. If a dentry is found, that is returned instead of - * allocating a new one. - * - * On successful return, the reference to the inode has been transferred - * to the dentry. In case of an error the reference on the inode is released. - * To make it easier to use in export operations a %NULL or IS_ERR inode may - * be passed in and will be the error will be propagate to the return value, - * with a %NULL @inode replaced by ERR_PTR(-ESTALE). - */ -struct dentry *d_obtain_alias(struct inode *inode) +static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) { static const struct qstr anonstring = QSTR_INIT("/", 1); struct dentry *tmp; @@ -1830,7 +1806,10 @@ struct dentry *d_obtain_alias(struct inode *inode) } /* attach a disconnected dentry */ - add_flags = d_flags_for_inode(inode) | DCACHE_DISCONNECTED; + add_flags = d_flags_for_inode(inode); + + if (disconnected) + add_flags |= DCACHE_DISCONNECTED; spin_lock(&tmp->d_lock); tmp->d_inode = inode; @@ -1851,8 +1830,52 @@ struct dentry *d_obtain_alias(struct inode *inode) iput(inode); return res; } + +/** + * d_obtain_alias - find or allocate a DISCONNECTED dentry for a given inode + * @inode: inode to allocate the dentry for + * + * Obtain a dentry for an inode resulting from NFS filehandle conversion or + * similar open by handle operations. The returned dentry may be anonymous, + * or may have a full name (if the inode was already in the cache). + * + * When called on a directory inode, we must ensure that the inode only ever + * has one dentry. If a dentry is found, that is returned instead of + * allocating a new one. + * + * On successful return, the reference to the inode has been transferred + * to the dentry. In case of an error the reference on the inode is released. + * To make it easier to use in export operations a %NULL or IS_ERR inode may + * be passed in and the error will be propagated to the return value, + * with a %NULL @inode replaced by ERR_PTR(-ESTALE). + */ +struct dentry *d_obtain_alias(struct inode *inode) +{ + return __d_obtain_alias(inode, 1); +} EXPORT_SYMBOL(d_obtain_alias); +/** + * d_obtain_root - find or allocate a dentry for a given inode + * @inode: inode to allocate the dentry for + * + * Obtain an IS_ROOT dentry for the root of a filesystem. + * + * We must ensure that directory inodes only ever have one dentry. If a + * dentry is found, that is returned instead of allocating a new one. + * + * On successful return, the reference to the inode has been transferred + * to the dentry. In case of an error the reference on the inode is + * released. A %NULL or IS_ERR inode may be passed in and will be the + * error will be propagate to the return value, with a %NULL @inode + * replaced by ERR_PTR(-ESTALE). + */ +struct dentry *d_obtain_root(struct inode *inode) +{ + return __d_obtain_alias(inode, 0); +} +EXPORT_SYMBOL(d_obtain_root); + /** * d_add_ci - lookup or allocate new dentry with case-exact name * @inode: the inode case-insensitive lookup has found @@ -2683,6 +2706,11 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) dput(new); return ERR_PTR(-EIO); } + if (d_ancestor(new, dentry)) { + spin_unlock(&inode->i_lock); + dput(new); + return ERR_PTR(-EIO); + } write_seqlock(&rename_lock); __d_materialise_dentry(dentry, new); write_sequnlock(&rename_lock); @@ -2736,7 +2764,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) struct dentry *alias; /* Does an aliased dentry already exist? */ - alias = __d_find_alias(inode, 0); + alias = __d_find_alias(inode); if (alias) { actual = alias; write_seqlock(&rename_lock);