linux/fs/orangefs/dcache.c

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/*
* (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 "orangefs-kernel.h"
/* Returns 1 if dentry can still be trusted, else 0. */
static int orangefs_revalidate_lookup(struct dentry *dentry)
{
struct dentry *parent_dentry = dget_parent(dentry);
struct inode *parent_inode = parent_dentry->d_inode;
struct orangefs_inode_s *parent = ORANGEFS_I(parent_inode);
struct inode *inode = dentry->d_inode;
struct orangefs_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(ORANGEFS_VFS_OP_LOOKUP);
if (!new_op)
goto out_put_parent;
new_op->upcall.req.lookup.sym_follow = ORANGEFS_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,
ORANGEFS_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, "orangefs_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 orangefs_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 out;
}
gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: inode valid.\n", __func__);
inode = dentry->d_inode;
/* skip root handle lookups. */
if (is_root_handle(inode)) {
ret = 1;
goto out;
}
/* lookup the object. */
if (orangefs_revalidate_lookup(dentry))
ret = 1;
out:
return ret;
}
const struct dentry_operations orangefs_dentry_operations = {
.d_revalidate = orangefs_d_revalidate,
};