Commit 9ef7db7f authored by Alexey Khoroshilov's avatar Alexey Khoroshilov Committed by Al Viro

ufs: fix deadlocks introduced by sb mutex merge

Commit 0244756e ("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: default avatarAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 81b6b061
...@@ -902,9 +902,6 @@ void ufs_evict_inode(struct inode * inode) ...@@ -902,9 +902,6 @@ void ufs_evict_inode(struct inode * inode)
invalidate_inode_buffers(inode); invalidate_inode_buffers(inode);
clear_inode(inode); clear_inode(inode);
if (want_delete) { if (want_delete)
lock_ufs(inode->i_sb); ufs_free_inode(inode);
ufs_free_inode (inode);
unlock_ufs(inode->i_sb);
}
} }
...@@ -126,12 +126,12 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry, ...@@ -126,12 +126,12 @@ static int ufs_symlink (struct inode * dir, struct dentry * dentry,
if (l > sb->s_blocksize) if (l > sb->s_blocksize)
goto out_notlocked; goto out_notlocked;
lock_ufs(dir->i_sb);
inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO); inode = ufs_new_inode(dir, S_IFLNK | S_IRWXUGO);
err = PTR_ERR(inode); err = PTR_ERR(inode);
if (IS_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) { if (l > UFS_SB(sb)->s_uspi->s_maxsymlinklen) {
/* slow symlink */ /* slow symlink */
inode->i_op = &ufs_symlink_inode_operations; inode->i_op = &ufs_symlink_inode_operations;
...@@ -181,13 +181,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) ...@@ -181,13 +181,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
struct inode * inode; struct inode * inode;
int err; int err;
lock_ufs(dir->i_sb);
inode_inc_link_count(dir);
inode = ufs_new_inode(dir, S_IFDIR|mode); inode = ufs_new_inode(dir, S_IFDIR|mode);
err = PTR_ERR(inode);
if (IS_ERR(inode)) if (IS_ERR(inode))
goto out_dir; return PTR_ERR(inode);
inode->i_op = &ufs_dir_inode_operations; inode->i_op = &ufs_dir_inode_operations;
inode->i_fop = &ufs_dir_operations; inode->i_fop = &ufs_dir_operations;
...@@ -195,6 +191,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) ...@@ -195,6 +191,9 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
inode_inc_link_count(inode); inode_inc_link_count(inode);
lock_ufs(dir->i_sb);
inode_inc_link_count(dir);
err = ufs_make_empty(inode, dir); err = ufs_make_empty(inode, dir);
if (err) if (err)
goto out_fail; goto out_fail;
...@@ -212,7 +211,6 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode) ...@@ -212,7 +211,6 @@ static int ufs_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
inode_dec_link_count(inode); inode_dec_link_count(inode);
inode_dec_link_count(inode); inode_dec_link_count(inode);
iput (inode); iput (inode);
out_dir:
inode_dec_link_count(dir); inode_dec_link_count(dir);
unlock_ufs(dir->i_sb); unlock_ufs(dir->i_sb);
goto out; goto out;
......
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