forked from Minki/linux
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 "orangefs-kernel.h"
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/* Returns 1 if dentry can still be trusted, else 0. */
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static int orangefs_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 orangefs_inode_s *parent = ORANGEFS_I(parent_inode);
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struct inode *inode = dentry->d_inode;
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struct orangefs_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(ORANGEFS_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 = ORANGEFS_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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ORANGEFS_NAME_MAX);
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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, "orangefs_lookup",
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get_interruptible_flag(parent_inode));
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/* Positive dentry: reject if error or not the same inode. */
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if (inode) {
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if (err) {
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gossip_debug(GOSSIP_DCACHE_DEBUG,
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"%s:%s:%d lookup failure.\n",
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__FILE__, __func__, __LINE__);
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goto out_drop;
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}
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if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
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inode)) {
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gossip_debug(GOSSIP_DCACHE_DEBUG,
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"%s:%s:%d no match.\n",
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__FILE__, __func__, __LINE__);
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goto out_drop;
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}
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/* Negative dentry: reject if success or error other than ENOENT. */
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} else {
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gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
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__func__);
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if (!err || err != -ENOENT) {
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if (new_op->downcall.status != 0)
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gossip_debug(GOSSIP_DCACHE_DEBUG,
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"%s:%s:%d lookup failure.\n",
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__FILE__, __func__, __LINE__);
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goto out_drop;
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}
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}
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dentry->d_time = jiffies + dcache_timeout_msecs*HZ/1000;
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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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gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
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__FILE__, __func__, __LINE__);
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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 orangefs_d_revalidate(struct dentry *dentry, unsigned int flags)
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{
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int ret;
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if (time_before(jiffies, dentry->d_time))
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return 1;
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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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/* skip root handle lookups. */
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if (dentry->d_inode && is_root_handle(dentry->d_inode))
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return 1;
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/*
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* If this passes, the positive dentry still exists or the negative
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* dentry still does not exist.
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*/
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if (!orangefs_revalidate_lookup(dentry))
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return 0;
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/* We do not need to continue with negative dentries. */
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if (!dentry->d_inode)
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goto out;
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/* Now we must perform a getattr to validate the inode contents. */
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ret = orangefs_inode_check_changed(dentry->d_inode);
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if (ret < 0) {
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gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
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__FILE__, __func__, __LINE__);
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return 0;
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}
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if (ret == 0)
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return 0;
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out:
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gossip_debug(GOSSIP_DCACHE_DEBUG,
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"%s: negative dentry or positive dentry and inode valid.\n",
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__func__);
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return 1;
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}
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const struct dentry_operations orangefs_dentry_operations = {
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.d_revalidate = orangefs_d_revalidate,
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};
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