ocfs2 has a problem with open(O_CREAT|O_EXCL). Once you've created the
file, you can't restart the open(), because O_CREAT|O_EXCL will trigger
-EEXIST.
The problem is that ocfs2 is catching the signal ->permission(), called
by may_open(). This happens after ->create() has successfully created
the file. ocfs2_permission() has to get a cluster lock, and this is
what can be interrupted by a signal. Now, obviously we want to block
signals in the O_CREAT|O_EXCL case, but ocfs2_permission() has no way of
knowing it just got called from open_namei_create().
We key on the MAY_CREATE flag passed to permission to block signals.
Signed-off-by: Joel Becker <joel.becker@xxxxxxxxxx>
---
fs/ocfs2/file.c | 13 +++++++++++++
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 89fc8ee..b8749fa 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1141,9 +1141,18 @@ bail:
int ocfs2_permission(struct inode *inode, int mask)
{
int ret;
+ sigset_t oldset;
mlog_entry_void();
+ /*
+ * If this inode was just created by open(O_CREAT|O_EXCL), we
+ * can't allow signal restarting. So we need to block signals
+ * around the cluster locking.
+ */
+ if (mask & MAY_CREATE)
+ ocfs2_block_signals(&oldset);
+
ret = ocfs2_inode_lock(inode, NULL, 0);
if (ret) {
if (ret != -ENOENT)
@@ -1154,7 +1163,11 @@ int ocfs2_permission(struct inode *inode, int mask)
ret = generic_permission(inode, mask, ocfs2_check_acl);
ocfs2_inode_unlock(inode, 0);
+
out:
+ if (mask & MAY_CREATE)
+ ocfs2_unblock_signals(&oldset);
+
mlog_exit(ret);
return ret;
}
--
1.6.3.3
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