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From: "J. Bruce Fields" <bfields@redhat.com>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	jlayton@redhat.com, Dave Chinner <david@fromorbit.com>,
	"J. Bruce Fields" <bfields@redhat.com>,
	Andreas Dilger <adilger.kernel@dilger.ca>
Subject: [PATCH 01/13] vfs: pull ext4's double-i_mutex-locking into common code
Date: Thu, 19 Sep 2013 16:50:25 -0400	[thread overview]
Message-ID: <1379623837-30798-2-git-send-email-bfields@redhat.com> (raw)
In-Reply-To: <1379623837-30798-1-git-send-email-bfields@redhat.com>

From: "J. Bruce Fields" <bfields@redhat.com>

We want to do this elsewhere as well.

Also catch any attempts to use it for directories (where this ordering
would conflict with ancestor-first directory ordering in lock_rename).

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/ext4/ext4.h        |    2 --
 fs/ext4/ioctl.c       |    4 ++--
 fs/ext4/move_extent.c |   40 ++--------------------------------------
 fs/inode.c            |   36 ++++++++++++++++++++++++++++++++++++
 include/linux/fs.h    |    3 +++
 5 files changed, 43 insertions(+), 42 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index af815ea..d01d623 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2734,8 +2734,6 @@ extern void ext4_double_down_write_data_sem(struct inode *first,
 					    struct inode *second);
 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
 					  struct inode *donor_inode);
-void ext4_inode_double_lock(struct inode *inode1, struct inode *inode2);
-void ext4_inode_double_unlock(struct inode *inode1, struct inode *inode2);
 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
 			     __u64 start_orig, __u64 start_donor,
 			     __u64 len, __u64 *moved_len);
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a569d33..60589b6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -130,7 +130,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
 
 	/* Protect orig inodes against a truncate and make sure,
 	 * that only 1 swap_inode_boot_loader is running. */
-	ext4_inode_double_lock(inode, inode_bl);
+	lock_two_nondirectories(inode, inode_bl);
 
 	truncate_inode_pages(&inode->i_data, 0);
 	truncate_inode_pages(&inode_bl->i_data, 0);
@@ -205,7 +205,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
 	ext4_inode_resume_unlocked_dio(inode);
 	ext4_inode_resume_unlocked_dio(inode_bl);
 
-	ext4_inode_double_unlock(inode, inode_bl);
+	unlock_two_nondirectories(inode, inode_bl);
 
 	iput(inode_bl);
 
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 7fa4d85..773b503 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -1203,42 +1203,6 @@ mext_check_arguments(struct inode *orig_inode,
 }
 
 /**
- * ext4_inode_double_lock - Lock i_mutex on both @inode1 and @inode2
- *
- * @inode1:	the inode structure
- * @inode2:	the inode structure
- *
- * Lock two inodes' i_mutex
- */
-void
-ext4_inode_double_lock(struct inode *inode1, struct inode *inode2)
-{
-	BUG_ON(inode1 == inode2);
-	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);
-	}
-}
-
-/**
- * ext4_inode_double_unlock - Release i_mutex on both @inode1 and @inode2
- *
- * @inode1:     the inode that is released first
- * @inode2:     the inode that is released second
- *
- */
-
-void
-ext4_inode_double_unlock(struct inode *inode1, struct inode *inode2)
-{
-	mutex_unlock(&inode1->i_mutex);
-	mutex_unlock(&inode2->i_mutex);
-}
-
-/**
  * ext4_move_extents - Exchange the specified range of a file
  *
  * @o_filp:		file structure of the original file
@@ -1327,7 +1291,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
 		return -EINVAL;
 	}
 	/* Protect orig and donor inodes against a truncate */
-	ext4_inode_double_lock(orig_inode, donor_inode);
+	lock_two_nondirectories(orig_inode, donor_inode);
 
 	/* Wait for all existing dio workers */
 	ext4_inode_block_unlocked_dio(orig_inode);
@@ -1535,7 +1499,7 @@ out:
 	ext4_double_up_write_data_sem(orig_inode, donor_inode);
 	ext4_inode_resume_unlocked_dio(orig_inode);
 	ext4_inode_resume_unlocked_dio(donor_inode);
-	ext4_inode_double_unlock(orig_inode, donor_inode);
+	unlock_two_nondirectories(orig_inode, donor_inode);
 
 	return ret;
 }
diff --git a/fs/inode.c b/fs/inode.c
index b33ba8e..9271c48 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -951,6 +951,42 @@ 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
+ * @inode2: second inode to lock
+ */
+void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
+{
+	WARN_ON_ONCE(S_ISDIR(inode1->i_mode));
+	if (inode1 == inode2 || !inode2) {
+		mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
+		return;
+	}
+	WARN_ON_ONCE(S_ISDIR(inode2->i_mode));
+	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);
+
+/**
+ * unlock_two_nondirectories - release locks from lock_two_nondirectories()
+ * @inode1: first inode to unlock
+ * @inode2: second inode to unlock
+ */
+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 3f40547..9f83ed3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -637,6 +637,9 @@ 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


  reply	other threads:[~2013-09-19 20:50 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-19 20:50 [PATCH 00/13] Implement NFSv4 delegations, take 12 J. Bruce Fields
2013-09-19 20:50 ` J. Bruce Fields [this message]
2013-09-19 20:50 ` [PATCH 02/13] vfs: don't use PARENT/CHILD lock classes for non-directories J. Bruce Fields
2013-09-19 20:50 ` [PATCH 03/13] vfs: rename I_MUTEX_QUOTA now that it's not used for quotas J. Bruce Fields
2013-09-19 20:50 ` [PATCH 04/13] vfs: take i_mutex on renamed file J. Bruce Fields
     [not found] ` <1379623837-30798-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-09-19 20:50   ` [PATCH 05/13] locks: introduce new FL_DELEG lock flag J. Bruce Fields
2013-09-19 20:50   ` [PATCH 06/13] locks: implement delegations J. Bruce Fields
2013-09-19 20:50   ` [PATCH 08/13] locks: break delegations on unlink J. Bruce Fields
2013-09-19 20:50   ` [PATCH 12/13] locks: break delegations on any attribute modification J. Bruce Fields
2013-10-02 13:54   ` [PATCH 00/13] Implement NFSv4 delegations, take 12 J. Bruce Fields
     [not found]     ` <20131002135423.GA14808-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>
2013-10-02 20:16       ` J. Bruce Fields
2013-10-03 19:41         ` J. Bruce Fields
2013-10-07 15:20           ` J. Bruce Fields
2013-09-19 20:50 ` [PATCH 07/13] namei: minor vfs_unlink cleanup J. Bruce Fields
2013-09-19 20:50 ` [PATCH 09/13] locks: helper functions for delegation breaking J. Bruce Fields
2013-09-19 20:50 ` [PATCH 10/13] locks: break delegations on rename J. Bruce Fields
2013-09-19 20:50 ` [PATCH 11/13] locks: break delegations on link J. Bruce Fields
2013-09-19 20:50 ` [PATCH 13/13] locks: close potential race between setlease and open J. Bruce Fields
  -- strict thread matches above, loose matches on Subject: below --
2013-09-11 20:03 [PATCH 00/13] Implement NFSv4 delegations, take 11 J. Bruce Fields
     [not found] ` <1378929799-1110-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-09-11 20:03   ` [PATCH 01/13] vfs: pull ext4's double-i_mutex-locking into common code J. Bruce Fields

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