ceph: clean up on forwarded aborted mds request

[safe/jmp/linux-2.6] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 22506eb..6dcee88 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -230,43 +230,55 @@ struct super_block *freeze_bdev(struct block_device *bdev)
        int error = 0;
 
        mutex_lock(&bdev->bd_fsfreeze_mutex);
-       if (bdev->bd_fsfreeze_count > 0) {
-               bdev->bd_fsfreeze_count++;
+       if (++bdev->bd_fsfreeze_count > 1) {
+               /*
+                * We don't even need to grab a reference - the first call
+                * to freeze_bdev grab an active reference and only the last
+                * thaw_bdev drops it.
+                */
                sb = get_super(bdev);
+               drop_super(sb);
+               mutex_unlock(&bdev->bd_fsfreeze_mutex);
+               return sb;
+       }
+
+       sb = get_active_super(bdev);
+       if (!sb)
+               goto out;
+       if (sb->s_flags & MS_RDONLY) {
+               sb->s_frozen = SB_FREEZE_TRANS;
+               up_write(&sb->s_umount);
                mutex_unlock(&bdev->bd_fsfreeze_mutex);
                return sb;
        }
-       bdev->bd_fsfreeze_count++;
 
-       sb = get_super(bdev);
-       if (sb && !(sb->s_flags & MS_RDONLY)) {
-               sb->s_frozen = SB_FREEZE_WRITE;
-               smp_wmb();
+       sb->s_frozen = SB_FREEZE_WRITE;
+       smp_wmb();
 
-               sync_filesystem(sb);
+       sync_filesystem(sb);
 
-               sb->s_frozen = SB_FREEZE_TRANS;
-               smp_wmb();
-
-               sync_blockdev(sb->s_bdev);
-
-               if (sb->s_op->freeze_fs) {
-                       error = sb->s_op->freeze_fs(sb);
-                       if (error) {
-                               printk(KERN_ERR
-                                       "VFS:Filesystem freeze failed\n");
-                               sb->s_frozen = SB_UNFROZEN;
-                               drop_super(sb);
-                               bdev->bd_fsfreeze_count--;
-                               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                               return ERR_PTR(error);
-                       }
+       sb->s_frozen = SB_FREEZE_TRANS;
+       smp_wmb();
+
+       sync_blockdev(sb->s_bdev);
+
+       if (sb->s_op->freeze_fs) {
+               error = sb->s_op->freeze_fs(sb);
+               if (error) {
+                       printk(KERN_ERR
+                               "VFS:Filesystem freeze failed\n");
+                       sb->s_frozen = SB_UNFROZEN;
+                       deactivate_locked_super(sb);
+                       bdev->bd_fsfreeze_count--;
+                       mutex_unlock(&bdev->bd_fsfreeze_mutex);
+                       return ERR_PTR(error);
                }
        }
+       up_write(&sb->s_umount);
 
+ out:
        sync_blockdev(bdev);
        mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
        return sb;      /* thaw_bdev releases s->s_umount */
 }
 EXPORT_SYMBOL(freeze_bdev);
@@ -280,43 +292,44 @@ EXPORT_SYMBOL(freeze_bdev);
  */
 int thaw_bdev(struct block_device *bdev, struct super_block *sb)
 {
-       int error = 0;
+       int error = -EINVAL;
 
        mutex_lock(&bdev->bd_fsfreeze_mutex);
-       if (!bdev->bd_fsfreeze_count) {
-               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-               return -EINVAL;
-       }
-
-       bdev->bd_fsfreeze_count--;
-       if (bdev->bd_fsfreeze_count > 0) {
-               if (sb)
-                       drop_super(sb);
-               mutex_unlock(&bdev->bd_fsfreeze_mutex);
-               return 0;
-       }
-
-       if (sb) {
-               BUG_ON(sb->s_bdev != bdev);
-               if (!(sb->s_flags & MS_RDONLY)) {
-                       if (sb->s_op->unfreeze_fs) {
-                               error = sb->s_op->unfreeze_fs(sb);
-                               if (error) {
-                                       printk(KERN_ERR
-                                               "VFS:Filesystem thaw failed\n");
-                                       sb->s_frozen = SB_FREEZE_TRANS;
-                                       bdev->bd_fsfreeze_count++;
-                                       mutex_unlock(&bdev->bd_fsfreeze_mutex);
-                                       return error;
-                               }
-                       }
-                       sb->s_frozen = SB_UNFROZEN;
-                       smp_wmb();
-                       wake_up(&sb->s_wait_unfrozen);
+       if (!bdev->bd_fsfreeze_count)
+               goto out_unlock;
+
+       error = 0;
+       if (--bdev->bd_fsfreeze_count > 0)
+               goto out_unlock;
+
+       if (!sb)
+               goto out_unlock;
+
+       BUG_ON(sb->s_bdev != bdev);
+       down_write(&sb->s_umount);
+       if (sb->s_flags & MS_RDONLY)
+               goto out_unfrozen;
+
+       if (sb->s_op->unfreeze_fs) {
+               error = sb->s_op->unfreeze_fs(sb);
+               if (error) {
+                       printk(KERN_ERR
+                               "VFS:Filesystem thaw failed\n");
+                       sb->s_frozen = SB_FREEZE_TRANS;
+                       bdev->bd_fsfreeze_count++;
+                       mutex_unlock(&bdev->bd_fsfreeze_mutex);
+                       return error;
                }
-               drop_super(sb);
        }
 
+out_unfrozen:
+       sb->s_frozen = SB_UNFROZEN;
+       smp_wmb();
+       wake_up(&sb->s_wait_unfrozen);
+
+       if (sb)
+               deactivate_locked_super(sb);
+out_unlock:
        mutex_unlock(&bdev->bd_fsfreeze_mutex);
        return 0;
 }
@@ -391,10 +404,28 @@ static loff_t block_llseek(struct file *file, loff_t offset, int origin)
  *     NULL first argument is nfsd_sync_dir() and that's not a directory.
  */
  
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int blkdev_fsync(struct file *filp, struct dentry *dentry, int datasync)
 {
-       return sync_blockdev(I_BDEV(filp->f_mapping->host));
+       struct inode *bd_inode = filp->f_mapping->host;
+       struct block_device *bdev = I_BDEV(bd_inode);
+       int error;
+
+       /*
+        * There is no need to serialise calls to blkdev_issue_flush with
+        * i_mutex and doing so causes performance issues with concurrent
+        * O_SYNC writers to a block device.
+        */
+       mutex_unlock(&bd_inode->i_mutex);
+
+       error = blkdev_issue_flush(bdev, NULL);
+       if (error == -EOPNOTSUPP)
+               error = 0;
+
+       mutex_lock(&bd_inode->i_mutex);
+
+       return error;
 }
+EXPORT_SYMBOL(blkdev_fsync);
 
 /*
  * pseudo-fs
@@ -1236,8 +1267,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
                        bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
                }
        } else {
-               put_disk(disk);
                module_put(disk->fops->owner);
+               put_disk(disk);
                disk = NULL;
                if (bdev->bd_contains == bdev) {
                        if (bdev->bd_disk->fops->open) {
@@ -1458,7 +1489,7 @@ const struct file_operations def_blk_fops = {
        .aio_read       = generic_file_aio_read,
        .aio_write      = blkdev_aio_write,
        .mmap           = generic_file_mmap,
-       .fsync          = block_fsync,
+       .fsync          = blkdev_fsync,
        .unlocked_ioctl = block_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl   = compat_blkdev_ioctl,