diff options
| author | Alexey Khoroshilov <khoroshilov@ispras.ru> | 2014-09-02 11:40:17 +0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-09-07 13:26:39 -0400 |
| commit | 9ef7db7f38d0472dd9c444e42d5c5175ccbe5451 (patch) | |
| tree | 38098751b8e07a868788fda862f96763b55d0763 | |
| parent | 81b6b06197606b4bef4e427a197aeb808e8d89e1 (diff) | |
| download | lwn-9ef7db7f38d0472dd9c444e42d5c5175ccbe5451.tar.gz lwn-9ef7db7f38d0472dd9c444e42d5c5175ccbe5451.zip | |
ufs: fix deadlocks introduced by sb mutex merge
Commit 0244756edc4b ("ufs: sb mutex merge + mutex_destroy") introduces
deadlocks in ufs_new_inode() and ufs_free_inode().
Most callers of that functions acqure the mutex by themselves and
ufs_{new,free}_inode() do that via lock_ufs(),
i.e we have an unavoidable double lock.
The patch proposes to resolve the issue by making sure that
ufs_{new,free}_inode() are not called with the mutex held.
Found by Linux Driver Verification project (linuxtesting.org).
Cc: stable@vger.kernel.org # 3.16
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/ufs/inode.c | 7 | ||||
| -rw-r--r-- | fs/ufs/namei.c | 14 |
2 files changed, 8 insertions, 13 deletions
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c index 7c580c97990e..be7d42c7d938 100644 --- a/fs/ufs/inode.c +++ b/fs/ufs/inode.c @@ -902,9 +902,6 @@ void ufs_evict_inode(struct inode * inode) invalidate_inode_buffers(inode); clear_inode(inode); - if (want_delete) { - lock_ufs(inode->i_sb); - ufs_free_inode (inode); - unlock_ufs(inode->i_sb); - } + if (want_delete) + ufs_free_inode(inode); } diff --git a/fs/ufs/namei.c b/fs/ufs/namei.c index 90d74b8f8eba..2df62a73f20c 100644 --- a/fs/ufs/namei.c +++ b/fs/ufs/namei.c @@ -126,12 +126,12 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry, if (l > sb->s_blocksize) goto out_notlocked; - lock_ufs(dir->i_sb); inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); err = PTR_ERR(inode); if (IS_ERR(inode)) - goto out; + goto out_notlocked; + lock_ufs(dir->i_sb); if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) { /* slow symlink */ inode->i_op = &ufs_symlink_inode_operations; @@ -181,13 +181,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) struct inode * inode; int err; - lock_ufs(dir->i_sb); - inode_inc_link_count(dir); - inode = ufs_new_inode(dir, S_IFDIR|mode); - err = PTR_ERR(inode); if (IS_ERR(inode)) - goto out_dir; + return PTR_ERR(inode); inode->i_op = &ufs_dir_inode_operations; inode->i_fop = &ufs_dir_operations; @@ -195,6 +191,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) inode_inc_link_count(inode); + lock_ufs(dir->i_sb); + inode_inc_link_count(dir); + err = ufs_make_empty(inode, dir); if (err) goto out_fail; @@ -212,7 +211,6 @@ out_fail: inode_dec_link_count(inode); inode_dec_link_count(inode); iput (inode); -out_dir: inode_dec_link_count(dir); unlock_ufs(dir->i_sb); goto out; |