From fdb5d702253aff821cae9e98913fb3136a8a73fe Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 18 Apr 2018 15:48:42 -0700 Subject: [PATCH] f2fs: call unlock_new_inode() before d_instantiate() Cherry-pick from origin/upstream-f2fs-stable-linux-4.4.y: dafecc032ea1 ("f2fs: call unlock_new_inode() before d_instantiate()") xfstest generic/429 sometimes hangs on f2fs, caused by a thread being unable to take a directory's i_rwsem for write in vfs_rmdir(). In the test, one thread repeatedly creates and removes a directory, and other threads repeatedly look up a file in the directory. The bug is that f2fs_mkdir() calls d_instantiate() before unlock_new_inode(), resulting in the directory inode being exposed to lookups before it has been fully initialized. And with CONFIG_DEBUG_LOCK_ALLOC, unlock_new_inode() reinitializes ->i_rwsem, corrupting its state when it is already held. Fix it by calling unlock_new_inode() before d_instantiate(). This matches what other filesystems do. Fixes: 57397d86c62d ("f2fs: add inode operations for special inodes") Change-Id: I1c50a45449b89ce590ae2caccb7d499f4b717665 Signed-off-by: Eric Biggers Signed-off-by: Jaegeuk Kim --- fs/f2fs/namei.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 5ec20f077629..fecae8685d2a 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -294,8 +294,8 @@ static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode, alloc_nid_done(sbi, ino); - d_instantiate(dentry, inode); unlock_new_inode(inode); + d_instantiate(dentry, inode); if (IS_DIRSYNC(dir)) f2fs_sync_fs(sbi->sb, 1); @@ -594,8 +594,8 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry, err = page_symlink(inode, disk_link.name, disk_link.len); err_out: - d_instantiate(dentry, inode); unlock_new_inode(inode); + d_instantiate(dentry, inode); /* * Let's flush symlink data in order to avoid broken symlink as much as @@ -658,8 +658,8 @@ static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) alloc_nid_done(sbi, inode->i_ino); - d_instantiate(dentry, inode); unlock_new_inode(inode); + d_instantiate(dentry, inode); if (IS_DIRSYNC(dir)) f2fs_sync_fs(sbi->sb, 1); @@ -710,8 +710,8 @@ static int f2fs_mknod(struct inode *dir, struct dentry *dentry, alloc_nid_done(sbi, inode->i_ino); - d_instantiate(dentry, inode); unlock_new_inode(inode); + d_instantiate(dentry, inode); if (IS_DIRSYNC(dir)) f2fs_sync_fs(sbi->sb, 1);