BKL-removal: Use unlocked_ioctl for jfs

Convert jfs_ioctl over to not use the BKL. The only potential race
I could see was with two ioctls in parallel changing the flags
and losing the updates. Use the i_mutex to protect against this.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>

4 files changed, 13 insertions, 7 deletions

diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 87eb93694af7..713ff4c2f807 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -112,5 +112,5 @@ const struct file_operations jfs_file_operations = {
         .splice_write   = generic_file_splice_write,
         .fsync          = jfs_fsync,
         .release        = jfs_release,
-        .ioctl          = jfs_ioctl,
+        .unlocked_ioctl = jfs_ioctl,
 };
diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c
index dfda12a073e1..fc82eccf408a 100644
--- a/fs/jfs/ioctl.c
+++ b/fs/jfs/ioctl.c
@@ -51,9 +51,9 @@ static long jfs_map_ext2(unsigned long flags, int from)
 }
 
 
-int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
-                unsigned long arg)
+long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+        struct inode *inode = filp->f_dentry->d_inode;
         struct jfs_inode_info *jfs_inode = JFS_IP(inode);
         unsigned int flags;
 
@@ -82,6 +82,10 @@ int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
                 /* Is it quota file? Do not allow user to mess with it */
                 if (IS_NOQUOTA(inode))
                         return -EPERM;
+
+                /* Lock against other parallel changes of flags */
+                mutex_lock(&inode->i_mutex);
+
                 jfs_get_inode_flags(jfs_inode);
                 oldflags = jfs_inode->mode2;
 
@@ -92,8 +96,10 @@ int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
                 if ((oldflags & JFS_IMMUTABLE_FL) ||
                         ((flags ^ oldflags) &
                         (JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
-                        if (!capable(CAP_LINUX_IMMUTABLE))
+                        if (!capable(CAP_LINUX_IMMUTABLE)) {
+                                mutex_unlock(&inode->i_mutex);
                                 return -EPERM;
+                        }
                 }
 
                 flags = flags & JFS_FL_USER_MODIFIABLE;
@@ -101,6 +107,7 @@ int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
                 jfs_inode->mode2 = flags;
 
                 jfs_set_inode_flags(inode);
+                mutex_unlock(&inode->i_mutex);
                 inode->i_ctime = CURRENT_TIME_SEC;
                 mark_inode_dirty(inode);
                 return 0;
diff --git a/fs/jfs/jfs_inode.h b/fs/jfs/jfs_inode.h
index 95a6a11425e5..570fd5e3ef61 100644
--- a/fs/jfs/jfs_inode.h
+++ b/fs/jfs/jfs_inode.h
@@ -22,8 +22,7 @@ struct fid;
 
 extern struct inode *ialloc(struct inode *, umode_t);
 extern int jfs_fsync(struct file *, struct dentry *, int);
-extern int jfs_ioctl(struct inode *, struct file *,
-                        unsigned int, unsigned long);
+extern long jfs_ioctl(struct file *, unsigned int, unsigned long);
 extern struct inode *jfs_iget(struct super_block *, unsigned long);
 extern int jfs_commit_inode(struct inode *, int);
 extern int jfs_write_inode(struct inode*, int);
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index 403cfc24c6fe..6440904a051c 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1556,7 +1556,7 @@ const struct file_operations jfs_dir_operations = {
         .read           = generic_read_dir,
         .readdir        = jfs_readdir,
         .fsync          = jfs_fsync,
-        .ioctl          = jfs_ioctl,
+        .unlocked_ioctl = jfs_ioctl,
 };
 
 static int jfs_ci_hash(struct dentry *dir, struct qstr *this)