Subject: [merged] ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock.patch removed from -mm tree
To: jiangyiwen@xxxxxxxxxx,jlbec@xxxxxxxxxxxx,joseph.qi@xxxxxxxxxx,mfasheh@xxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 04 Apr 2014 12:30:40 -0700
The patch titled
Subject: ocfs2: avoid system inode ref confusion by adding mutex lock
has been removed from the -mm tree. Its filename was
ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: jiangyiwen <jiangyiwen@xxxxxxxxxx>
Subject: ocfs2: avoid system inode ref confusion by adding mutex lock
The following case may lead to the same system inode ref in confusion.
A thread B thread
ocfs2_get_system_file_inode
->get_local_system_inode
->_ocfs2_get_system_file_inode
because of *arr == NULL,
ocfs2_get_system_file_inode
->get_local_system_inode
->_ocfs2_get_system_file_inode
gets first ref thru
_ocfs2_get_system_file_inode,
gets second ref thru igrab and
set *arr = inode
at the moment, B thread also gets
two refs, so lead to one more
inode ref.
So add mutex lock to avoid multi thread set two inode ref once at the same
time.
Signed-off-by: jiangyiwen <jiangyiwen@xxxxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/ocfs2.h | 2 ++
fs/ocfs2/super.c | 2 ++
fs/ocfs2/sysfile.c | 3 +++
3 files changed, 7 insertions(+)
diff -puN fs/ocfs2/ocfs2.h~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock fs/ocfs2/ocfs2.h
--- a/fs/ocfs2/ocfs2.h~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock
+++ a/fs/ocfs2/ocfs2.h
@@ -446,6 +446,8 @@ struct ocfs2_super
/* rb tree root for refcount lock. */
struct rb_root osb_rf_lock_tree;
struct ocfs2_refcount_tree *osb_ref_tree_lru;
+
+ struct mutex system_file_mutex;
};
#define OCFS2_SB(sb) ((struct ocfs2_super *)(sb)->s_fs_info)
diff -puN fs/ocfs2/super.c~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock fs/ocfs2/super.c
--- a/fs/ocfs2/super.c~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock
+++ a/fs/ocfs2/super.c
@@ -2100,6 +2100,8 @@ static int ocfs2_initialize_super(struct
spin_lock_init(&osb->osb_xattr_lock);
ocfs2_init_steal_slots(osb);
+ mutex_init(&osb->system_file_mutex);
+
atomic_set(&osb->alloc_stats.moves, 0);
atomic_set(&osb->alloc_stats.local_data, 0);
atomic_set(&osb->alloc_stats.bitmap_data, 0);
diff -puN fs/ocfs2/sysfile.c~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock fs/ocfs2/sysfile.c
--- a/fs/ocfs2/sysfile.c~ocfs2-avoid-system-inode-ref-confusion-by-adding-mutex-lock
+++ a/fs/ocfs2/sysfile.c
@@ -113,9 +113,11 @@ struct inode *ocfs2_get_system_file_inod
} else
arr = get_local_system_inode(osb, type, slot);
+ mutex_lock(&osb->system_file_mutex);
if (arr && ((inode = *arr) != NULL)) {
/* get a ref in addition to the array ref */
inode = igrab(inode);
+ mutex_unlock(&osb->system_file_mutex);
BUG_ON(!inode);
return inode;
@@ -129,6 +131,7 @@ struct inode *ocfs2_get_system_file_inod
*arr = igrab(inode);
BUG_ON(!*arr);
}
+ mutex_unlock(&osb->system_file_mutex);
return inode;
}
_
Patches currently in -mm which might be from jiangyiwen@xxxxxxxxxx are
origin.patch
ocfs2-fix-a-tiny-race-when-running-dirop_fileop_racer.patch
ocfs2-do-not-return-dlm_migrate_response_mastery_ref-to-avoid-endlessloop-during-umount.patch
ocfs2-manually-do-the-iput-once-ocfs2_add_entry-failed-in-ocfs2_symlink-and-ocfs2_mknod.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
