]> git.baikalelectronics.ru Git - kernel.git/commit
ufs: Fix possible deadlock when looking up directories
authorJan Kara <jack@suse.cz>
Tue, 2 Jun 2015 09:26:34 +0000 (11:26 +0200)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 16 Jun 2015 06:08:12 +0000 (02:08 -0400)
commit60e184fb33d30af47a9f7518ba58ff6c38dc4105
tree62b4f0f249c523eaba9fe4b8ce407782922a5b11
parent8654f87a0b898189dc61e9f6043b0c9379f70fcd
ufs: Fix possible deadlock when looking up directories

Commit 4b7c6745dad351f8e (ufs: deal with nfsd/iget races) made ufs
create inodes with I_NEW flag set. However ufs_mkdir() never cleared
this flag. Thus if someone ever tried to lookup the directory by inode
number, he would deadlock waiting for I_NEW to be cleared. Luckily this
mostly happens only if the filesystem is exported over NFS since
otherwise we have the inode attached to dentry and don't look it up by
inode number. In rare cases dentry can get freed without inode being
freed and then we'd hit the deadlock even without NFS export.

Fix the problem by clearing I_NEW before instantiating new directory
inode.

Fixes: 4b7c6745dad351f8ed310f6e0e7972a4760d49a9
Reported-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/ufs/namei.c