VFS: factor out three helpers for FIBMAP/FIONBIO/FIOASYNC file ioctls

Factor out file-specific ioctl code into smaller helper functions, away from
file_ioctl().  This helps code readability and also reduces indentation inside
case statements.

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ioctl.c b/fs/ioctl.c
index e6500cd..683002f 100644 (file)
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -52,32 +52,34 @@ long vfs_ioctl(struct file *filp, unsigned int cmd,
        return error;
 }
 
+static int ioctl_fibmap(struct file *filp, int __user *p)
+{
+       struct address_space *mapping = filp->f_mapping;
+       int res, block;
+
+       /* do we support this mess? */
+       if (!mapping->a_ops->bmap)
+               return -EINVAL;
+       if (!capable(CAP_SYS_RAWIO))
+               return -EPERM;
+       res = get_user(block, p);
+       if (res)
+               return res;
+       lock_kernel();
+       res = mapping->a_ops->bmap(mapping, block);
+       unlock_kernel();
+       return put_user(res, p);
+}
+
 static int file_ioctl(struct file *filp, unsigned int cmd,
                unsigned long arg)
 {
-       int error;
-       int block;
        struct inode *inode = filp->f_path.dentry->d_inode;
        int __user *p = (int __user *)arg;
 
        switch (cmd) {
        case FIBMAP:
-       {
-               struct address_space *mapping = filp->f_mapping;
-               int res;
-               /* do we support this mess? */
-               if (!mapping->a_ops->bmap)
-                       return -EINVAL;
-               if (!capable(CAP_SYS_RAWIO))
-                       return -EPERM;
-               error = get_user(block, p);
-               if (error)
-                       return error;
-               lock_kernel();
-               res = mapping->a_ops->bmap(mapping, block);
-               unlock_kernel();
-               return put_user(res, p);
-       }
+               return ioctl_fibmap(filp, p);
        case FIGETBSZ:
                return put_user(inode->i_sb->s_blocksize, p);
        case FIONREAD:
@@ -87,6 +89,57 @@ static int file_ioctl(struct file *filp, unsigned int cmd,
        return vfs_ioctl(filp, cmd, arg);
 }
 
+static int ioctl_fionbio(struct file *filp, int __user *argp)
+{
+       unsigned int flag;
+       int on, error;
+
+       error = get_user(on, argp);
+       if (error)
+               return error;
+       flag = O_NONBLOCK;
+#ifdef __sparc__
+       /* SunOS compatibility item. */
+       if (O_NONBLOCK != O_NDELAY)
+               flag |= O_NDELAY;
+#endif
+       if (on)
+               filp->f_flags |= flag;
+       else
+               filp->f_flags &= ~flag;
+       return error;
+}
+
+static int ioctl_fioasync(unsigned int fd, struct file *filp,
+                         int __user *argp)
+{
+       unsigned int flag;
+       int on, error;
+
+       error = get_user(on, argp);
+       if (error)
+               return error;
+       flag = on ? FASYNC : 0;
+
+       /* Did FASYNC state change ? */
+       if ((flag ^ filp->f_flags) & FASYNC) {
+               if (filp->f_op && filp->f_op->fasync) {
+                       lock_kernel();
+                       error = filp->f_op->fasync(fd, filp, on);
+                       unlock_kernel();
+               } else
+                       error = -ENOTTY;
+       }
+       if (error)
+               return error;
+
+       if (on)
+               filp->f_flags |= FASYNC;
+       else
+               filp->f_flags &= ~FASYNC;
+       return error;
+}
+
 /*
  * When you add any new common ioctls to the switches above and below
  * please update compat_sys_ioctl() too.
@@ -97,8 +150,8 @@ static int file_ioctl(struct file *filp, unsigned int cmd,
 int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
             unsigned long arg)
 {
-       unsigned int flag;
-       int on, error = 0;
+       int error = 0;
+       int __user *argp = (int __user *)arg;
 
        switch (cmd) {
        case FIOCLEX:
@@ -110,43 +163,11 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
                break;
 
        case FIONBIO:
-               error = get_user(on, (int __user *)arg);
-               if (error)
-                       break;
-               flag = O_NONBLOCK;
-#ifdef __sparc__
-               /* SunOS compatibility item. */
-               if (O_NONBLOCK != O_NDELAY)
-                       flag |= O_NDELAY;
-#endif
-               if (on)
-                       filp->f_flags |= flag;
-               else
-                       filp->f_flags &= ~flag;
+               error = ioctl_fionbio(filp, argp);
                break;
 
        case FIOASYNC:
-               error = get_user(on, (int __user *)arg);
-               if (error)
-                       break;
-               flag = on ? FASYNC : 0;
-
-               /* Did FASYNC state change ? */
-               if ((flag ^ filp->f_flags) & FASYNC) {
-                       if (filp->f_op && filp->f_op->fasync) {
-                               lock_kernel();
-                               error = filp->f_op->fasync(fd, filp, on);
-                               unlock_kernel();
-                       } else
-                               error = -ENOTTY;
-               }
-               if (error != 0)
-                       break;
-
-               if (on)
-                       filp->f_flags |= FASYNC;
-               else
-                       filp->f_flags &= ~FASYNC;
+               error = ioctl_fioasync(fd, filp, argp);
                break;
 
        case FIOQSIZE: