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Subject[PATCH 06/14] fs/ntfs3: Changing locking in ntfs_rename
From
In some cases we can be in deadlock
because we tried to lock the same dir.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
fs/ntfs3/namei.c | 4 ++++
fs/ntfs3/ntfs_fs.h | 6 ++++++
2 files changed, 10 insertions(+)

diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c
index 1af02d4f6b4d..13d6acc0747f 100644
--- a/fs/ntfs3/namei.c
+++ b/fs/ntfs3/namei.c
@@ -305,6 +305,8 @@ static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,

ni_lock_dir(dir_ni);
ni_lock(ni);
+ if (dir_ni != new_dir_ni)
+ ni_lock_dir2(new_dir_ni);

is_bad = false;
err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
@@ -328,6 +330,8 @@ static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
ntfs_sync_inode(inode);
}

+ if (dir_ni != new_dir_ni)
+ ni_unlock(new_dir_ni);
ni_unlock(ni);
ni_unlock(dir_ni);
out:
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index c45a411f82f6..5fad93a2c3fd 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -333,6 +333,7 @@ enum ntfs_inode_mutex_lock_class {
NTFS_INODE_MUTEX_REPARSE,
NTFS_INODE_MUTEX_NORMAL,
NTFS_INODE_MUTEX_PARENT,
+ NTFS_INODE_MUTEX_PARENT2,
};

/*
@@ -1119,6 +1120,11 @@ static inline void ni_lock_dir(struct ntfs_inode *ni)
mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_PARENT);
}

+static inline void ni_lock_dir2(struct ntfs_inode *ni)
+{
+ mutex_lock_nested(&ni->ni_lock, NTFS_INODE_MUTEX_PARENT2);
+}
+
static inline void ni_unlock(struct ntfs_inode *ni)
{
mutex_unlock(&ni->ni_lock);
--
2.37.0

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