From: "J. Bruce Fields" <bfields@redhat.com>
To: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-nfs@vger.kernel.org, "J. Bruce Fields" <bfields@redhat.com>
Subject: [PATCH 2/5] exportfs: move most of reconnect_path to helper function
Date: Tue, 15 Oct 2013 16:39:30 -0400 [thread overview]
Message-ID: <1381869574-10662-3-git-send-email-bfields@redhat.com> (raw)
In-Reply-To: <1381869574-10662-1-git-send-email-bfields@redhat.com>
From: "J. Bruce Fields" <bfields@redhat.com>
Just cleanup, no change in functionality.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/exportfs/expfs.c | 147 +++++++++++++++++++++++++++------------------------
1 file changed, 79 insertions(+), 68 deletions(-)
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index 455b0bb..63996d2 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -107,6 +107,82 @@ static void clear_disconnected(struct dentry *dentry)
}
/*
+ * Return the parent directory on success.
+ *
+ * Return NULL to keep trying.
+ *
+ * Otherwise return an error.
+ */
+static int reconnect_one(struct vfsmount *mnt, struct dentry *pd, char *nbuf, int *noprogress)
+{
+ struct dentry *ppd;
+ struct dentry *npd;
+ int err;
+ /*
+ * Getting the parent can't be supported generically, the
+ * locking is too icky.
+ *
+ * If it can't be done, we just return EACCES. If you were
+ * depending on the dcache finding the parent for you, you lose
+ * if there's a reboot or inodes get flushed.
+ */
+ ppd = ERR_PTR(-EACCES);
+
+ mutex_lock(&pd->d_inode->i_mutex);
+ if (mnt->mnt_sb->s_export_op->get_parent)
+ ppd = mnt->mnt_sb->s_export_op->get_parent(pd);
+ mutex_unlock(&pd->d_inode->i_mutex);
+
+ if (IS_ERR(ppd)) {
+ err = PTR_ERR(ppd);
+ dprintk("%s: get_parent of %ld failed, err %d\n",
+ __func__, dentry->d_inode->i_ino, err);
+ return err;
+ }
+
+ dprintk("%s: find name of %lu in %lu\n", __func__,
+ dentry->d_inode->i_ino, parent->d_inode->i_ino);
+ err = exportfs_get_name(mnt, ppd, nbuf, pd);
+ if (err) {
+ dput(ppd);
+ if (err == -ENOENT)
+ /* some race between get_parent and
+ * get_name? just try again
+ */
+ return 0;
+ return err;
+ }
+ dprintk("%s: found name: %s\n", __func__, nbuf);
+ mutex_lock(&ppd->d_inode->i_mutex);
+ npd = lookup_one_len(nbuf, ppd, strlen(nbuf));
+ mutex_unlock(&ppd->d_inode->i_mutex);
+ if (IS_ERR(npd)) {
+ err = PTR_ERR(npd);
+ dprintk("%s: lookup failed: %d\n",
+ __func__, err);
+ dput(ppd);
+ return err;
+ }
+ /* we didn't really want npd, we really wanted
+ * a side-effect of the lookup.
+ * hopefully, npd == pd, though it isn't really
+ * a problem if it isn't
+ */
+ if (npd == pd)
+ *noprogress = 0;
+ else
+ printk("%s: npd != pd\n", __func__);
+ dput(npd);
+ dput(ppd);
+ if (IS_ROOT(pd)) {
+ /* something went wrong, we have to give up */
+ dput(pd);
+ return -ESTALE;
+ }
+ return 0;
+}
+
+/*
* Make sure target_dir is fully connected to the dentry tree.
*
* It may already be, as the flag isn't always updated when connection happens.
@@ -140,75 +216,10 @@ reconnect_path(struct vfsmount *mnt, struct dentry *target_dir, char *nbuf)
/*
* We have hit the top of a disconnected path, try to
* find parent and connect.
- *
- * Racing with some other process renaming a directory
- * isn't much of a problem here. If someone renames
- * the directory, it will end up properly connected,
- * which is what we want
- *
- * Getting the parent can't be supported generically,
- * the locking is too icky.
- *
- * Instead we just return EACCES. If server reboots
- * or inodes get flushed, you lose
- */
- struct dentry *ppd = ERR_PTR(-EACCES);
- struct dentry *npd;
-
- mutex_lock(&pd->d_inode->i_mutex);
- if (mnt->mnt_sb->s_export_op->get_parent)
- ppd = mnt->mnt_sb->s_export_op->get_parent(pd);
- mutex_unlock(&pd->d_inode->i_mutex);
-
- if (IS_ERR(ppd)) {
- err = PTR_ERR(ppd);
- dprintk("%s: get_parent of %ld failed, err %d\n",
- __func__, pd->d_inode->i_ino, err);
- dput(pd);
- break;
- }
-
- dprintk("%s: find name of %lu in %lu\n", __func__,
- pd->d_inode->i_ino, ppd->d_inode->i_ino);
- err = exportfs_get_name(mnt, ppd, nbuf, pd);
- if (err) {
- dput(ppd);
- dput(pd);
- if (err == -ENOENT)
- /* some race between get_parent and
- * get_name? just try again
- */
- continue;
- break;
- }
- dprintk("%s: found name: %s\n", __func__, nbuf);
- mutex_lock(&ppd->d_inode->i_mutex);
- npd = lookup_one_len(nbuf, ppd, strlen(nbuf));
- mutex_unlock(&ppd->d_inode->i_mutex);
- if (IS_ERR(npd)) {
- err = PTR_ERR(npd);
- dprintk("%s: lookup failed: %d\n",
- __func__, err);
- dput(ppd);
- dput(pd);
- break;
- }
- /* we didn't really want npd, we really wanted
- * a side-effect of the lookup.
- * hopefully, npd == pd, though it isn't really
- * a problem if it isn't
*/
- if (npd == pd)
- noprogress = 0;
- else
- printk("%s: npd != pd\n", __func__);
- dput(npd);
- dput(ppd);
- if (IS_ROOT(pd)) {
- /* something went wrong, we have to give up */
- dput(pd);
- break;
- }
+ err = reconnect_one(mnt, pd, nbuf, &noprogress);
+ if (err)
+ return err;
}
dput(pd);
}
--
1.7.9.5
next prev parent reply other threads:[~2013-10-15 20:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-15 20:39 simplify reconnecting dentries looked up by filehandle J. Bruce Fields
2013-10-15 20:39 ` [PATCH 1/5] exportfs: clear DISCONNECTED on all parents sooner J. Bruce Fields
[not found] ` <1381869574-10662-2-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-10-16 7:13 ` Christoph Hellwig
[not found] ` <20131016071343.GB27799-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2013-10-16 13:56 ` J. Bruce Fields
2013-10-15 20:39 ` J. Bruce Fields [this message]
[not found] ` <1381869574-10662-3-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-10-16 7:16 ` [PATCH 2/5] exportfs: move most of reconnect_path to helper function Christoph Hellwig
2013-10-15 20:39 ` [PATCH 4/5] exportfs: slight reorganization of reconnect loop J. Bruce Fields
2013-10-16 7:19 ` Christoph Hellwig
[not found] ` <1381869574-10662-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-10-15 20:39 ` [PATCH 3/5] exportfs: make variable names more helpful J. Bruce Fields
[not found] ` <1381869574-10662-4-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-10-16 7:18 ` Christoph Hellwig
2013-10-15 20:39 ` [PATCH 5/5] exportfs: fix quadratic behavior in filehandle lookup J. Bruce Fields
[not found] ` <1381869574-10662-6-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-10-16 8:04 ` Christoph Hellwig
2013-10-16 18:29 ` J. Bruce Fields
2013-10-16 19:22 ` J. Bruce Fields
2013-10-16 22:00 ` J. Bruce Fields
2013-10-16 18:24 ` simplify reconnecting dentries looked up by filehandle Christoph Hellwig
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