+static struct inode *osd_iget_check(struct osd_thread_info *info,
+ struct osd_device *dev,
+ const struct lu_fid *fid,
+ struct osd_inode_id *id,
+ bool cached)
+{
+ struct inode *inode;
+ int rc = 0;
+ ENTRY;
+
+ /* The cached OI mapping is trustable. If we cannot locate the inode
+ * via the cached OI mapping, then return the failure to the caller
+ * directly without further OI checking. */
+
+ inode = ldiskfs_iget(osd_sb(dev), id->oii_ino);
+ if (IS_ERR(inode)) {
+ rc = PTR_ERR(inode);
+ if (cached || (rc != -ENOENT && rc != -ESTALE)) {
+ CDEBUG(D_INODE, "no inode: ino = %u, rc = %d\n",
+ id->oii_ino, rc);
+
+ GOTO(put, rc);
+ }
+
+ goto check_oi;
+ }
+
+ if (is_bad_inode(inode)) {
+ rc = -ENOENT;
+ if (cached) {
+ CDEBUG(D_INODE, "bad inode: ino = %u\n", id->oii_ino);
+
+ GOTO(put, rc);
+ }
+
+ goto check_oi;
+ }
+
+ if (id->oii_gen != OSD_OII_NOGEN &&
+ inode->i_generation != id->oii_gen) {
+ rc = -ESTALE;
+ if (cached) {
+ CDEBUG(D_INODE, "unmatched inode: ino = %u, "
+ "oii_gen = %u, i_generation = %u\n",
+ id->oii_ino, id->oii_gen, inode->i_generation);
+
+ GOTO(put, rc);
+ }
+
+ goto check_oi;
+ }
+
+ if (inode->i_nlink == 0) {
+ rc = -ENOENT;
+ if (cached) {
+ CDEBUG(D_INODE, "stale inode: ino = %u\n", id->oii_ino);
+
+ GOTO(put, rc);
+ }
+
+ goto check_oi;
+ }
+
+check_oi:
+ if (rc != 0) {
+ LASSERTF(rc == -ESTALE || rc == -ENOENT, "rc = %d\n", rc);
+
+ rc = osd_oi_lookup(info, dev, fid, id, OI_CHECK_FLD);
+ /* XXX: There are four possible cases:
+ * 1. rc = 0.
+ * Backup/restore caused the OI invalid.
+ * 2. rc = 0.
+ * Someone unlinked the object but NOT removed
+ * the OI mapping, such as mount target device
+ * as ldiskfs, and modify something directly.
+ * 3. rc = -ENOENT.
+ * Someone just removed the object between the
+ * former oi_lookup and the iget. It is normal.
+ * 4. Other failure cases.
+ *
+ * Generally, when the device is mounted, it will
+ * auto check whether the system is restored from
+ * file-level backup or not. We trust such detect
+ * to distinguish the 1st case from the 2nd case. */
+ if (rc == 0) {
+ if (!IS_ERR(inode) && inode->i_generation != 0 &&
+ inode->i_generation == id->oii_gen)
+ /* "id->oii_gen != OSD_OII_NOGEN" is for
+ * "@cached == false" case. */
+ rc = -ENOENT;
+ else
+ rc = -EREMCHG;
+ } else {
+ /* If the OI mapping was in OI file before the
+ * osd_iget_check(), but now, it is disappear,
+ * then it must be removed by race. That is a
+ * normal race case. */
+ }
+ } else {
+ if (id->oii_gen == OSD_OII_NOGEN)
+ osd_id_gen(id, inode->i_ino, inode->i_generation);
+
+ /* Do not update file c/mtime in ldiskfs.
+ * NB: we don't have any lock to protect this because we don't
+ * have reference on osd_object now, but contention with
+ * another lookup + attr_set can't happen in the tiny window
+ * between if (...) and set S_NOCMTIME. */
+ if (!(inode->i_flags & S_NOCMTIME))
+ inode->i_flags |= S_NOCMTIME;
+ }
+
+ GOTO(put, rc);
+
+put:
+ if (rc != 0) {
+ if (!IS_ERR(inode))
+ iput(inode);
+
+ inode = ERR_PTR(rc);
+ }
+
+ return inode;
+}
+