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>

1 files changed, 75 insertions, 54 deletions

diff --git a/fs/ioctl.c b/fs/ioctl.c
index e6500cd12258..683002fefa55 100644
--- 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: