jbd2: move bdget out of critical section

bdget() should not be called when we hold spinlocks since
it might sleep.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhu Yanhai <gaoyang.zyh@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 90407b8..33dd3ef 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2413,10 +2413,12 @@ const char *jbd2_dev_to_name(dev_t device)
        new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL);
        if (!new_dev)
                return "NODEV-ALLOCFAILURE"; /* Something non-NULL */
+       bd = bdget(device);
        spin_lock(&devname_cache_lock);
        if (devcache[i]) {
                if (devcache[i]->device == device) {
                        kfree(new_dev);
+                       bdput(bd);
                        ret = devcache[i]->devname;
                        spin_unlock(&devname_cache_lock);
                        return ret;
@@ -2425,7 +2427,6 @@ const char *jbd2_dev_to_name(dev_t device)
        }
        devcache[i] = new_dev;
        devcache[i]->device = device;
-       bd = bdget(device);
        if (bd) {
                bdevname(bd, devcache[i]->devname);
                bdput(bd);