fs/orangefs/dcache.c

   1 /*
   2  * (C) 2001 Clemson University and The University of Chicago
   3  *
   4  * See COPYING in top-level directory.
   5  */
   6
   7 /*
   8  *  Implementation of dentry (directory cache) functions.
   9  */
  10
  11 #include "protocol.h"
  12 #include "pvfs2-kernel.h"
  13
  14 /* Returns 1 if dentry can still be trusted, else 0. */
  15 static int pvfs2_revalidate_lookup(struct dentry *dentry)
  16 {
  17         struct dentry *parent_dentry = dget_parent(dentry);
  18         struct inode *parent_inode = parent_dentry->d_inode;
  19         struct pvfs2_inode_s *parent = PVFS2_I(parent_inode);
  20         struct inode *inode = dentry->d_inode;
  21         struct pvfs2_kernel_op_s *new_op;
  22         int ret = 0;
  23         int err = 0;
  24
  25         gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: attempting lookup.\n", __func__);
  26
  27         new_op = op_alloc(PVFS2_VFS_OP_LOOKUP);
  28         if (!new_op)
  29                 goto out_put_parent;
  30
  31         new_op->upcall.req.lookup.sym_follow = PVFS2_LOOKUP_LINK_NO_FOLLOW;
  32         new_op->upcall.req.lookup.parent_refn = parent->refn;
  33         strncpy(new_op->upcall.req.lookup.d_name,
  34                 dentry->d_name.name,
  35                 PVFS2_NAME_LEN);
  36
  37         gossip_debug(GOSSIP_DCACHE_DEBUG,
  38                      "%s:%s:%d interrupt flag [%d]\n",
  39                      __FILE__,
  40                      __func__,
  41                      __LINE__,
  42                      get_interruptible_flag(parent_inode));
  43
  44         err = service_operation(new_op, "pvfs2_lookup",
  45                         get_interruptible_flag(parent_inode));
  46         if (err)
  47                 goto out_drop;
  48
  49         if (new_op->downcall.status != 0 ||
  50             !match_handle(new_op->downcall.resp.lookup.refn.khandle, inode)) {
  51                 gossip_debug(GOSSIP_DCACHE_DEBUG,
  52                         "%s:%s:%d "
  53                         "lookup failure |%s| or no match |%s|.\n",
  54                         __FILE__,
  55                         __func__,
  56                         __LINE__,
  57                         new_op->downcall.status ? "true" : "false",
  58                         match_handle(new_op->downcall.resp.lookup.refn.khandle,
  59                                         inode) ? "false" : "true");
  60                 gossip_debug(GOSSIP_DCACHE_DEBUG,
  61                              "%s:%s:%d revalidate failed\n",
  62                              __FILE__, __func__, __LINE__);
  63                 goto out_drop;
  64         }
  65
  66         ret = 1;
  67 out_release_op:
  68         op_release(new_op);
  69 out_put_parent:
  70         dput(parent_dentry);
  71         return ret;
  72 out_drop:
  73         d_drop(dentry);
  74         goto out_release_op;
  75 }
  76
  77 /*
  78  * Verify that dentry is valid.
  79  *
  80  * Should return 1 if dentry can still be trusted, else 0
  81  */
  82 static int pvfs2_d_revalidate(struct dentry *dentry, unsigned int flags)
  83 {
  84         struct inode *inode;
  85         int ret = 0;
  86
  87         if (flags & LOOKUP_RCU)
  88                 return -ECHILD;
  89
  90         gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
  91                      __func__, dentry);
  92
  93         /* find inode from dentry */
  94         if (!dentry->d_inode) {
  95                 gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
  96                              __func__);
  97                 goto invalid_exit;
  98         }
  99
 100         gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: inode valid.\n", __func__);
 101         inode = dentry->d_inode;
 102
 103         /*
 104          * first perform a lookup to make sure that the object not only
 105          * exists, but is still in the expected place in the name space
 106          */
 107         if (!is_root_handle(inode)) {
 108                 if (!pvfs2_revalidate_lookup(dentry))
 109                         goto invalid_exit;
 110         } else {
 111                 gossip_debug(GOSSIP_DCACHE_DEBUG,
 112                              "%s: root handle, lookup skipped.\n",
 113                              __func__);
 114         }
 115
 116         /* now perform getattr */
 117         gossip_debug(GOSSIP_DCACHE_DEBUG,
 118                      "%s: doing getattr: inode: %p, handle: %pU\n",
 119                      __func__,
 120                      inode,
 121                      get_khandle_from_ino(inode));
 122         ret = pvfs2_inode_getattr(inode, PVFS_ATTR_SYS_ALL_NOHINT);
 123         gossip_debug(GOSSIP_DCACHE_DEBUG,
 124                      "%s: getattr %s (ret = %d), returning %s for dentry i_count=%d\n",
 125                      __func__,
 126                      (ret == 0 ? "succeeded" : "failed"),
 127                      ret,
 128                      (ret == 0 ? "valid" : "INVALID"),
 129                      atomic_read(&inode->i_count));
 130         if (ret != 0)
 131                 goto invalid_exit;
 132
 133         /* dentry is valid! */
 134         return 1;
 135
 136 invalid_exit:
 137         return 0;
 138 }
 139
 140 const struct dentry_operations pvfs2_dentry_operations = {
 141         .d_revalidate = pvfs2_d_revalidate,
 142 };