fs/smb/client/fscache.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *   CIFS filesystem cache interface
   4  *
   5  *   Copyright (c) 2010 Novell, Inc.
   6  *   Author(s): Suresh Jayaraman <[email protected]>
   7  *
   8  */
   9 #include "fscache.h"
  10 #include "cifsglob.h"
  11 #include "cifs_debug.h"
  12 #include "cifs_fs_sb.h"
  13 #include "cifsproto.h"
  14
  15 /*
  16  * Key for fscache inode.  [!] Contents must match comparisons in cifs_find_inode().
  17  */
  18 struct cifs_fscache_inode_key {
  19
  20         __le64  uniqueid;       /* server inode number */
  21         __le64  createtime;     /* creation time on server */
  22         u8      type;           /* S_IFMT file type */
  23 } __packed;
  24
  25 static void cifs_fscache_fill_volume_coherency(
  26         struct cifs_tcon *tcon,
  27         struct cifs_fscache_volume_coherency_data *cd)
  28 {
  29         memset(cd, 0, sizeof(*cd));
  30         cd->resource_id         = cpu_to_le64(tcon->resource_id);
  31         cd->vol_create_time     = tcon->vol_create_time;
  32         cd->vol_serial_number   = cpu_to_le32(tcon->vol_serial_number);
  33 }
  34
  35 int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
  36 {
  37         struct cifs_fscache_volume_coherency_data cd;
  38         struct TCP_Server_Info *server = tcon->ses->server;
  39         struct fscache_volume *vcookie;
  40         const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr;
  41         size_t slen, i;
  42         char *sharename;
  43         char *key;
  44         int ret = -ENOMEM;
  45
  46         if (tcon->fscache_acquired)
  47                 return 0;
  48
  49         mutex_lock(&tcon->fscache_lock);
  50         if (tcon->fscache_acquired) {
  51                 mutex_unlock(&tcon->fscache_lock);
  52                 return 0;
  53         }
  54         tcon->fscache_acquired = true;
  55
  56         tcon->fscache = NULL;
  57         switch (sa->sa_family) {
  58         case AF_INET:
  59         case AF_INET6:
  60                 break;
  61         default:
  62                 mutex_unlock(&tcon->fscache_lock);
  63                 cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
  64                 return -EINVAL;
  65         }
  66
  67         memset(&key, 0, sizeof(key));
  68
  69         sharename = extract_sharename(tcon->tree_name);
  70         if (IS_ERR(sharename)) {
  71                 mutex_unlock(&tcon->fscache_lock);
  72                 cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
  73                 return PTR_ERR(sharename);
  74         }
  75
  76         slen = strlen(sharename);
  77         for (i = 0; i < slen; i++)
  78                 if (sharename[i] == '/')
  79                         sharename[i] = ';';
  80
  81         key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename);
  82         if (!key)
  83                 goto out;
  84
  85         cifs_fscache_fill_volume_coherency(tcon, &cd);
  86         vcookie = fscache_acquire_volume(key,
  87                                          NULL, /* preferred_cache */
  88                                          &cd, sizeof(cd));
  89         cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie);
  90         if (IS_ERR(vcookie)) {
  91                 if (vcookie != ERR_PTR(-EBUSY)) {
  92                         ret = PTR_ERR(vcookie);
  93                         goto out_2;
  94                 }
  95                 pr_err("Cache volume key already in use (%s)\n", key);
  96                 vcookie = NULL;
  97                 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
  98                                     netfs_trace_tcon_ref_see_fscache_collision);
  99         } else {
 100                 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
 101                                     netfs_trace_tcon_ref_see_fscache_okay);
 102         }
 103
 104         tcon->fscache = vcookie;
 105         ret = 0;
 106 out_2:
 107         kfree(key);
 108 out:
 109         kfree(sharename);
 110         mutex_unlock(&tcon->fscache_lock);
 111         return ret;
 112 }
 113
 114 void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 115 {
 116         struct cifs_fscache_volume_coherency_data cd;
 117
 118         cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
 119
 120         cifs_fscache_fill_volume_coherency(tcon, &cd);
 121         fscache_relinquish_volume(tcon->fscache, &cd, false);
 122         tcon->fscache = NULL;
 123         trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
 124                             netfs_trace_tcon_ref_see_fscache_relinq);
 125 }
 126
 127 void cifs_fscache_get_inode_cookie(struct inode *inode)
 128 {
 129         struct cifs_fscache_inode_coherency_data cd;
 130         struct cifs_fscache_inode_key key;
 131         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 132         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 133         struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
 134
 135         key.uniqueid    = cpu_to_le64(cifsi->uniqueid);
 136         key.createtime  = cpu_to_le64(cifsi->createtime);
 137         key.type        = (inode->i_mode & S_IFMT) >> 12;
 138         cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd);
 139
 140         cifsi->netfs.cache =
 141                 fscache_acquire_cookie(tcon->fscache, 0,
 142                                        &key, sizeof(key),
 143                                        &cd, sizeof(cd),
 144                                        i_size_read(&cifsi->netfs.inode));
 145         if (cifsi->netfs.cache)
 146                 mapping_set_release_always(inode->i_mapping);
 147 }
 148
 149 void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
 150 {
 151         if (update) {
 152                 struct cifs_fscache_inode_coherency_data cd;
 153                 loff_t i_size = i_size_read(inode);
 154
 155                 cifs_fscache_fill_coherency(inode, &cd);
 156                 fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size);
 157         } else {
 158                 fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL);
 159         }
 160 }
 161
 162 void cifs_fscache_release_inode_cookie(struct inode *inode)
 163 {
 164         struct cifsInodeInfo *cifsi = CIFS_I(inode);
 165         struct fscache_cookie *cookie = cifs_inode_cookie(inode);
 166
 167         if (cookie) {
 168                 cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie);
 169                 fscache_relinquish_cookie(cookie, false);
 170                 cifsi->netfs.cache = NULL;
 171         }
 172 }