LU-12137 osd-ldiskfs: create locked and unlocked versions of osd lookup code

[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_compat.c

diff --git a/lustre/osd-ldiskfs/osd_compat.c b/lustre/osd-ldiskfs/osd_compat.c
index cab030a..15c395f 100644 (file)
--- a/lustre/osd-ldiskfs/osd_compat.c
+++ b/lustre/osd-ldiskfs/osd_compat.c
@@ -66,31 +66,39 @@ static void osd_push_ctxt(const struct osd_device *dev,
        push_ctxt(save, newctxt);
 }
 
-/**
- * osd_lookup_one_len_unlocked
- *
- * @name:      pathname component to lookup
- * @base:      base directory to lookup from
- * @len:       maximum length @len should be interpreted to
- *
- * This should be called without the parent
- * i_mutex held, and will take the i_mutex itself.
- */
-struct dentry *osd_lookup_one_len_unlocked(const char *name,
-                                          struct dentry *base, int len)
+struct dentry *osd_lookup_one_len_common(struct osd_device *dev,
+                                        const char *name,
+                                        struct dentry *base, int len,
+                                        enum oi_check_flags flags)
 {
        struct dentry *dchild;
 
-       inode_lock(base->d_inode);
-       dchild = lookup_one_len(name, base, len);
-       inode_unlock(base->d_inode);
-
-       if (IS_ERR(dchild) || dchild->d_inode == NULL)
+       /*
+        * We can't use inode_is_locked() directly since we can't know
+        * if the current thread context took the lock earlier or if
+        * another thread context took the lock. OI_LOCKED tells us
+        * if the current thread context has already taken the lock.
+        */
+       if (!(flags & OI_LOCKED)) {
+               /* If another thread took this lock already we will
+                * just have to wait until the other thread is done.
+                */
+               inode_lock(base->d_inode);
+               dchild = lookup_one_len(name, base, len);
+               inode_unlock(base->d_inode);
+       } else {
+               /* This thread context already has taken the lock.
+                * Other threads will have to wait until we are done.
+                */
+               dchild = lookup_one_len(name, base, len);
+       }
+       if (IS_ERR(dchild))
                return dchild;
 
-       if (is_bad_inode(dchild->d_inode)) {
-               CERROR("bad inode returned %lu/%u\n",
-                      dchild->d_inode->i_ino, dchild->d_inode->i_generation);
+       if (dchild->d_inode && unlikely(is_bad_inode(dchild->d_inode))) {
+               CERROR("%s: bad inode returned %lu/%u: rc = -ENOENT\n",
+                      osd_name(dev), dchild->d_inode->i_ino,
+                      dchild->d_inode->i_generation);
                dput(dchild);
                dchild = ERR_PTR(-ENOENT);
        }
@@ -99,31 +107,37 @@ struct dentry *osd_lookup_one_len_unlocked(const char *name,
 }
 
 /**
- * osd_ios_lookup_one_len - lookup single pathname component
+ * osd_lookup_one_len_unlocked
  *
+ * @dev:       obd device we are searching
  * @name:      pathname component to lookup
  * @base:      base directory to lookup from
  * @len:       maximum length @len should be interpreted to
+ *
+ * Unlike osd_lookup_one_len, this should be called without the parent
+ * i_mutex held, and will take the i_mutex itself.
  */
-struct dentry *osd_ios_lookup_one_len(const char *name, struct dentry *base,
-                                     int len)
+struct dentry *osd_lookup_one_len_unlocked(struct osd_device *dev,
+                                          const char *name,
+                                          struct dentry *base, int len)
 {
-       struct dentry *dentry;
-
-       dentry = osd_lookup_one_len_unlocked(name, base, len);
-       if (IS_ERR(dentry)) {
-               int rc = PTR_ERR(dentry);
-
-               if (rc != -ENOENT)
-                       CERROR("Fail to find %.*s in %.*s (%lu/%u): rc = %d\n",
-                              len, name, base->d_name.len,
-                              base->d_name.name, base->d_inode->i_ino,
-                              base->d_inode->i_generation, rc);
-
-               return dentry;
-       }
+       return osd_lookup_one_len_common(dev, name, base, len, ~OI_LOCKED);
+}
 
-       return dentry;
+/**
+ * osd_lookup_one_len - lookup single pathname component
+ *
+ * @dev:       obd device we are searching
+ * @name:      pathname component to lookup
+ * @base:      base directory to lookup from
+ * @len:       maximum length @len should be interpreted to
+ *
+ * The caller must hold inode lock
+ */
+struct dentry *osd_lookup_one_len(struct osd_device *dev, const char *name,
+                                 struct dentry *base, int len)
+{
+       return osd_lookup_one_len_common(dev, name, base, len, OI_LOCKED);
 }
 
 /* utility to make a directory */
@@ -142,7 +156,7 @@ simple_mkdir(const struct lu_env *env, struct osd_device *osd,
 
        // ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
        CDEBUG(D_INODE, "creating directory %.*s\n", (int)strlen(name), name);
-       dchild = osd_lookup_one_len_unlocked(name, dir, strlen(name));
+       dchild = osd_lookup_one_len_unlocked(osd, name, dir, strlen(name));
        if (IS_ERR(dchild))
                RETURN(dchild);
 
@@ -222,7 +236,7 @@ static int osd_last_rcvd_subdir_count(struct osd_device *osd)
 
        ENTRY;
 
-       dlast = osd_lookup_one_len_unlocked(LAST_RCVD, osd_sb(osd)->s_root,
+       dlast = osd_lookup_one_len_unlocked(osd, LAST_RCVD, osd_sb(osd)->s_root,
                                            strlen(LAST_RCVD));
        if (IS_ERR(dlast))
                return PTR_ERR(dlast);
@@ -1442,7 +1456,7 @@ int osd_obj_spec_lookup(struct osd_thread_info *info, struct osd_device *osd,
                        RETURN(-ENOENT);
        }
 
-       dentry = osd_lookup_one_len_unlocked(name, root, strlen(name));
+       dentry = osd_lookup_one_len_unlocked(osd, name, root, strlen(name));
        if (!IS_ERR(dentry)) {
                inode = dentry->d_inode;
                if (inode) {