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

This patch adds ioctls to vfs for compatibility with legacy XFS
pre-allocation ioctls (XFS_IOC_*RESVP*). The implementation
effectively invokes sys_fallocate for the new ioctls.
Also handles the compat_ioctl case.
Note: These legacy ioctls are also implemented by OCFS2.

[AV: folded fixes from hch]

Signed-off-by: Ankit Jain <me@ankitjain.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Ankit Jain
2009-06-19 14:28:07 -04:00
committed by Al Viro
parent 01c031945f
commit 3e63cbb1ef
5 changed files with 139 additions and 29 deletions

View File

@@ -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);