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| author |   Yan, Zheng <zheng.z.yan@intel.com> | 2013-07-02 12:40:19 +0800 |
|---|---|---|
| committer |   Sage Weil <sage@inktank.com> | 2013-07-03 15:32:56 -0700 |
| commit | b415bf4f9fe25f39934f5c464125e4a2dffb6d08 (patch) | |
| tree | f38df9c1746a1419e7942afb4534625175a5d353 /fs/ceph/inode.c | |
| parent | ceph: avoid accessing invalid memory (diff) | |
| download | linux-dev-b415bf4f9fe25f39934f5c464125e4a2dffb6d08.tar.xz linux-dev-b415bf4f9fe25f39934f5c464125e4a2dffb6d08.zip | |
ceph: fix pending vmtruncate race
The locking order for pending vmtruncate is wrong, it can lead to
following race:
write wmtruncate work
------------------------ ----------------------
lock i_mutex
check i_truncate_pending check i_truncate_pending
truncate_inode_pages() lock i_mutex (blocked)
copy data to page cache
unlock i_mutex
truncate_inode_pages()
The fix is take i_mutex before calling __ceph_do_pending_vmtruncate()
Fixes: http://tracker.ceph.com/issues/5453
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'fs/ceph/inode.c')
| -rw-r--r-- | fs/ceph/inode.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index be0f7e20d62e..4906ada4a97c 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1465,7 +1465,9 @@ static void ceph_vmtruncate_work(struct work_struct *work) struct inode *inode = &ci->vfs_inode; dout("vmtruncate_work %p\n", inode); - __ceph_do_pending_vmtruncate(inode, true); + mutex_lock(&inode->i_mutex); + __ceph_do_pending_vmtruncate(inode); + mutex_unlock(&inode->i_mutex); iput(inode); } @@ -1492,7 +1494,7 @@ void ceph_queue_vmtruncate(struct inode *inode) * Make sure any pending truncation is applied before doing anything * that may depend on it. */ -void __ceph_do_pending_vmtruncate(struct inode *inode, bool needlock) +void __ceph_do_pending_vmtruncate(struct inode *inode) { struct ceph_inode_info *ci = ceph_inode(inode); u64 to; @@ -1525,11 +1527,7 @@ retry: ci->i_truncate_pending, to); spin_unlock(&ci->i_ceph_lock); - if (needlock) - mutex_lock(&inode->i_mutex); truncate_inode_pages(inode->i_mapping, to); - if (needlock) - mutex_unlock(&inode->i_mutex); spin_lock(&ci->i_ceph_lock); if (to == ci->i_truncate_size) { @@ -1588,7 +1586,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) if (ceph_snap(inode) != CEPH_NOSNAP) return -EROFS; - __ceph_do_pending_vmtruncate(inode, false); + __ceph_do_pending_vmtruncate(inode); err = inode_change_ok(inode, attr); if (err != 0) @@ -1770,7 +1768,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr) ceph_cap_string(dirtied), mask); ceph_mdsc_put_request(req); - __ceph_do_pending_vmtruncate(inode, false); + __ceph_do_pending_vmtruncate(inode); return err; out: spin_unlock(&ci->i_ceph_lock); |