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