fs: Add new pre-allocation ioctls to vfs for compatibility with legacy xfs ioctls

[sfrench/cifs-2.6.git] / fs / ioctl.c

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 001f8d3118f27329d89131feef43c7ba0c0b1a85..5612880fcbe7d7436f3579c7c1add7360170e407 100644 (file)
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -15,6 +15,7 @@
 #include <linux/uaccess.h>
 #include <linux/writeback.h>
 #include <linux/buffer_head.h>
+#include <linux/falloc.h>
 
 #include <asm/ioctls.h>
 
@@ -403,6 +404,37 @@ EXPORT_SYMBOL(generic_block_fiemap);
 
 #endif  /*  CONFIG_BLOCK  */
 
+/*
+ * This provides compatibility with legacy XFS pre-allocation ioctls
+ * which predate the fallocate syscall.
+ *
+ * Only the l_start, l_len and l_whence fields of the 'struct space_resv'
+ * are used here, rest are ignored.
+ */
+int ioctl_preallocate(struct file *filp, void __user *argp)
+{
+       struct inode *inode = filp->f_path.dentry->d_inode;
+       struct space_resv sr;
+
+       if (copy_from_user(&sr, argp, sizeof(sr)))
+               return -EFAULT;
+
+       switch (sr.l_whence) {
+       case SEEK_SET:
+               break;
+       case SEEK_CUR:
+               sr.l_start += filp->f_pos;
+               break;
+       case SEEK_END:
+               sr.l_start += i_size_read(inode);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return do_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
+}
+
 static int file_ioctl(struct file *filp, unsigned int cmd,
                unsigned long arg)
 {
@@ -414,6 +446,9 @@ static int file_ioctl(struct file *filp, unsigned int cmd,
                return ioctl_fibmap(filp, p);
        case FIONREAD:
                return put_user(i_size_read(inode) - filp->f_pos, p);
+       case FS_IOC_RESVSP:
+       case FS_IOC_RESVSP64:
+               return ioctl_preallocate(filp, p);
        }
 
        return vfs_ioctl(filp, cmd, arg);