/*
* (C) 2001 Clemson University and The University of Chicago
*
* See COPYING in top-level directory.
*/
/*
* Implementation of dentry (directory cache) functions.
*/
#include "protocol.h"
#include "pvfs2-kernel.h"
/* Returns 1 if dentry can still be trusted, else 0. */
static int pvfs2_revalidate_lookup(struct dentry *dentry)
{
struct dentry *parent_dentry = dget_parent(dentry);
struct inode *parent_inode = parent_dentry->d_inode;
struct pvfs2_inode_s *parent = PVFS2_I(parent_inode);
struct inode *inode = dentry->d_inode;
struct pvfs2_kernel_op_s *new_op;
int ret = 0;
int err = 0;
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__);
new_op = op_alloc(PVFS2_VFS_OP_LOOKUP);
if (!new_op)
goto out_put_parent;
new_op->upcall.req.lookup.sym_follow = PVFS2_LOOKUP_LINK_NO_FOLLOW;
new_op->upcall.req.lookup.parent_refn = parent->refn;
strncpy(new_op->upcall.req.lookup.d_name,
dentry->d_name.name,
PVFS2_NAME_LEN);
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d interrupt flag [%d]\n",
__FILE__,
__func__,
__LINE__,
get_interruptible_flag(parent_inode));
err = service_operation(new_op, "pvfs2_lookup",
get_interruptible_flag(parent_inode));
if (err)
goto out_drop;
if (new_op->downcall.status != 0 ||
!match_handle(new_op->downcall.resp.lookup.refn.khandle, inode)) {
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d "
"lookup failure |%s| or no match |%s|.\n",
__FILE__,
__func__,
__LINE__,
new_op->downcall.status ? "true" : "false",
match_handle(new_op->downcall.resp.lookup.refn.khandle,
inode) ? "false" : "true");
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s:%s:%d revalidate failed\n",
__FILE__, __func__, __LINE__);
goto out_drop;
}
ret = 1;
out_release_op:
op_release(new_op);
out_put_parent:
dput(parent_dentry);
return ret;
out_drop:
d_drop(dentry);
goto out_release_op;
}
/*
* Verify that dentry is valid.
*
* Should return 1 if dentry can still be trusted, else 0
*/
static int pvfs2_d_revalidate(struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
int ret = 0;
if (flags & LOOKUP_RCU)
return -ECHILD;
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
__func__, dentry);
/* find inode from dentry */
if (!dentry->d_inode) {
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
__func__);
goto invalid_exit;
}
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: inode valid.\n", __func__);
inode = dentry->d_inode;
/*
* first perform a lookup to make sure that the object not only
* exists, but is still in the expected place in the name space
*/
if (!is_root_handle(inode)) {
if (!pvfs2_revalidate_lookup(dentry))
goto invalid_exit;
} else {
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s: root handle, lookup skipped.\n",
__func__);
}
/* now perform getattr */
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s: doing getattr: inode: %p, handle: %pU\n",
__func__,
inode,
get_khandle_from_ino(inode));
ret = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
gossip_debug(GOSSIP_DCACHE_DEBUG,
"%s: getattr %s (ret = %d), returning %s for dentry i_count=%d\n",
__func__,
(ret == 0 ? "succeeded" : "failed"),
ret,
(ret == 0 ? "valid" : "INVALID"),
atomic_read(&inode->i_count));
if (ret != 0)
goto invalid_exit;
/* dentry is valid! */
return 1;
invalid_exit:
return 0;
}
const struct dentry_operations pvfs2_dentry_operations = {
.d_revalidate = pvfs2_d_revalidate,
};
