Re: [PATCH 1/3] VFS/ioctl: Add punching-hole support to ioctl().

From: Sunil Mushran
Date: Thu Mar 31 2011 - 17:15:10 EST


Frankly I see no point extending the ioctl interface when we have
a syscall interface.

On 03/31/2011 12:33 AM, Tristan Ye wrote:
We're currently support two paths from VFS to preallocate unwritten
extents(from FS_IOC_RESVSP, or fallocate()), likewise, behavior of
punching-hole should be treated as the same, this patch tries to teach
file_ioctl() to handle FS_IOC_UNRESVSP, underlying filesystem like ocfs2
is wise enough to do the rest of work;-)

Signed-off-by: Tristan Ye<tristan.ye@xxxxxxxxxx>
---
fs/ioctl.c | 10 +++++++---
include/linux/falloc.h | 2 ++
2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/ioctl.c b/fs/ioctl.c
index 1d9b9fc..234e26f 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -422,7 +422,7 @@ EXPORT_SYMBOL(generic_block_fiemap);
* 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)
+int ioctl_preallocate(struct file *filp, void __user *argp, int mode)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct space_resv sr;
@@ -443,7 +443,7 @@ int ioctl_preallocate(struct file *filp, void __user *argp)
return -EINVAL;
}

- return do_fallocate(filp, FALLOC_FL_KEEP_SIZE, sr.l_start, sr.l_len);
+ return do_fallocate(filp, mode, sr.l_start, sr.l_len);
}

static int file_ioctl(struct file *filp, unsigned int cmd,
@@ -459,7 +459,11 @@ static int file_ioctl(struct file *filp, unsigned int cmd,
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 ioctl_preallocate(filp, p, FALLOC_FL_KEEP_SIZE);
+ case FS_IOC_UNRESVSP:
+ case FS_IOC_UNRESVSP64:
+ return ioctl_preallocate(filp, p, FALLOC_FL_KEEP_SIZE |
+ FALLOC_FL_PUNCH_HOLE);
}

return vfs_ioctl(filp, cmd, arg);
diff --git a/include/linux/falloc.h b/include/linux/falloc.h
index 73e0b62..fd1e871 100644
--- a/include/linux/falloc.h
+++ b/include/linux/falloc.h
@@ -21,7 +21,9 @@ struct space_resv {
};

#define FS_IOC_RESVSP _IOW('X', 40, struct space_resv)
+#define FS_IOC_UNRESVSP _IOW('X', 41, struct space_resv)
#define FS_IOC_RESVSP64 _IOW('X', 42, struct space_resv)
+#define FS_IOC_UNRESVSP64 _IOW('X', 43, struct space_resv)

#endif /* __KERNEL__ */


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