Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:53089 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759385Ab2IEUzd (ORCPT ); Wed, 5 Sep 2012 16:55:33 -0400 From: "J. Bruce Fields" To: Al Viro Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, "J. Bruce Fields" , "Theodore Ts'o" , Andreas Dilger Subject: [RFC PATCH 02/13] vfs: pull ext4's double-i_mutex-locking into common code Date: Wed, 5 Sep 2012 16:55:12 -0400 Message-Id: <1346878524-10585-3-git-send-email-bfields@redhat.com> In-Reply-To: <1346878524-10585-1-git-send-email-bfields@redhat.com> References: <1346878524-10585-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" We want to do this elsewhere as well. Also, compare pointers instead of inode numbers. Cc: "Theodore Ts'o" Cc: Andreas Dilger Signed-off-by: J. Bruce Fields --- fs/ext4/move_extent.c | 21 ++------------------- fs/inode.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 3 +++ 3 files changed, 41 insertions(+), 19 deletions(-) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index c5826c6..b87d94a 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -1086,19 +1086,7 @@ mext_inode_double_lock(struct inode *inode1, struct inode *inode2) if (ret < 0) goto out; - if (inode1 == inode2) { - mutex_lock(&inode1->i_mutex); - goto out; - } - - if (inode1->i_ino < inode2->i_ino) { - mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); - } else { - mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD); - } - + lock_two_nondirectories(inode1, inode2); out: return ret; } @@ -1123,12 +1111,7 @@ mext_inode_double_unlock(struct inode *inode1, struct inode *inode2) if (ret < 0) goto out; - if (inode1) - mutex_unlock(&inode1->i_mutex); - - if (inode2 && inode2 != inode1) - mutex_unlock(&inode2->i_mutex); - + unlock_two_nondirectories(inode1, inode2); out: return ret; } diff --git a/fs/inode.c b/fs/inode.c index ac8d904..582843d 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -969,6 +969,42 @@ void unlock_new_inode(struct inode *inode) EXPORT_SYMBOL(unlock_new_inode); /** + * lock_two_nondirectories - take two i_mutexes on non-directory objects + * @inode1: first inode to lock; must be non-NULL + * @inode2: second inode to lock; optional, may equal first or be NULL. + */ +void lock_two_nondirectories(struct inode *inode1, struct inode *inode2) +{ + if (inode1 == inode2 || inode2 == NULL) + mutex_lock(&inode1->i_mutex); + else if (inode1 < inode2) { + mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); + + } else { + mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD); + } +} +EXPORT_SYMBOL(lock_two_nondirectories); + +/** + * lock_two_nondirectories - release locks from lock_two_nondirectories() + * @inode1: first inode to unlock + * @inode2: second inode to lock + * + * Arguments must be same as those given to corresponding + * lock_two_nondirectories() call. + */ +void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) +{ + mutex_unlock(&inode1->i_mutex); + if (inode2 && inode2 != inode1) + mutex_unlock(&inode2->i_mutex); +} +EXPORT_SYMBOL(unlock_two_nondirectories); + +/** * iget5_locked - obtain an inode from a mounted file system * @sb: super block of file system * @hashval: hash value (usually inode number) to get diff --git a/include/linux/fs.h b/include/linux/fs.h index aa11047..a179b69 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -895,6 +895,9 @@ enum inode_i_mutex_lock_class I_MUTEX_QUOTA }; +void lock_two_nondirectories(struct inode *, struct inode*); +void unlock_two_nondirectories(struct inode *, struct inode*); + /* * NOTE: in a 32bit arch with a preemptable kernel and * an UP compile the i_size_read/write must be atomic -- 1.7.9.5