diff options
Diffstat (limited to 'fs/btrfs/direct-io.c')
| -rw-r--r-- | fs/btrfs/direct-io.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/fs/btrfs/direct-io.c b/fs/btrfs/direct-io.c index f9fb2db6a1e4..364bce34f034 100644 --- a/fs/btrfs/direct-io.c +++ b/fs/btrfs/direct-io.c @@ -856,21 +856,27 @@ relock: * So here we disable page faults in the iov_iter and then retry if we * got -EFAULT, faulting in the pages before the retry. */ +again: from->nofault = true; dio = btrfs_dio_write(iocb, from, written); from->nofault = false; - /* - * iomap_dio_complete() will call btrfs_sync_file() if we have a dsync - * iocb, and that needs to lock the inode. So unlock it before calling - * iomap_dio_complete() to avoid a deadlock. - */ - btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); - - if (IS_ERR_OR_NULL(dio)) + if (IS_ERR_OR_NULL(dio)) { ret = PTR_ERR_OR_ZERO(dio); - else + } else { + /* + * If we have a synchronous write, we must make sure the fsync + * triggered by the iomap_dio_complete() call below doesn't + * deadlock on the inode lock - we are already holding it and we + * can't call it after unlocking because we may need to complete + * partial writes due to the input buffer (or parts of it) not + * being already faulted in. + */ + ASSERT(current->journal_info == NULL); + current->journal_info = BTRFS_TRANS_DIO_WRITE_STUB; ret = iomap_dio_complete(dio); + current->journal_info = NULL; + } /* No increment (+=) because iomap returns a cumulative value. */ if (ret > 0) @@ -897,10 +903,12 @@ relock: } else { fault_in_iov_iter_readable(from, left); prev_left = left; - goto relock; + goto again; } } + btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); + /* * If 'ret' is -ENOTBLK or we have not written all data, then it means * we must fallback to buffered IO. |