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ovl: add reflink/copyfile/dedup support

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Since set of arguments are so similar, handle in a common helper.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2018-07-18 15:44:42 +02:00
parent f7c72396d0
commit 8ede205541
1 changed files with 87 additions and 0 deletions
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87
fs/overlayfs/file.c
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@ -389,6 +389,89 @@ static long ovl_compat_ioctl(struct file *file, unsigned int cmd,
return ovl_ioctl(file, cmd, arg); return ovl_ioctl(file, cmd, arg);
} }
enum ovl_copyop {
OVL_COPY,
OVL_CLONE,
OVL_DEDUPE,
};
static ssize_t ovl_copyfile(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
u64 len, unsigned int flags, enum ovl_copyop op)
{
struct inode *inode_out = file_inode(file_out);
struct fd real_in, real_out;
const struct cred *old_cred;
ssize_t ret;
ret = ovl_real_fdget(file_out, &real_out);
if (ret)
return ret;
ret = ovl_real_fdget(file_in, &real_in);
if (ret) {
fdput(real_out);
return ret;
}
old_cred = ovl_override_creds(file_inode(file_out)->i_sb);
switch (op) {
case OVL_COPY:
ret = vfs_copy_file_range(real_in.file, pos_in,
real_out.file, pos_out, len, flags);
break;
case OVL_CLONE:
ret = vfs_clone_file_range(real_in.file, pos_in,
real_out.file, pos_out, len);
break;
case OVL_DEDUPE:
ret = vfs_dedupe_file_range_one(real_in.file, pos_in,
real_out.file, pos_out, len);
break;
}
revert_creds(old_cred);
/* Update size */
ovl_copyattr(ovl_inode_real(inode_out), inode_out);
fdput(real_in);
fdput(real_out);
return ret;
}
static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t len, unsigned int flags)
{
return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
OVL_COPY);
}
static int ovl_clone_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out, u64 len)
{
return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
OVL_CLONE);
}
static int ovl_dedupe_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out, u64 len)
{
/*
* Don't copy up because of a dedupe request, this wouldn't make sense
* most of the time (data would be duplicated instead of deduplicated).
*/
if (!ovl_inode_upper(file_inode(file_in)) ||
!ovl_inode_upper(file_inode(file_out)))
return -EPERM;
return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, 0,
OVL_DEDUPE);
}
const struct file_operations ovl_file_operations = { const struct file_operations ovl_file_operations = {
.open = ovl_open, .open = ovl_open,
.release = ovl_release, .release = ovl_release,
@ -400,4 +483,8 @@ const struct file_operations ovl_file_operations = {
.fallocate = ovl_fallocate, .fallocate = ovl_fallocate,
.unlocked_ioctl = ovl_ioctl, .unlocked_ioctl = ovl_ioctl,
.compat_ioctl = ovl_compat_ioctl, .compat_ioctl = ovl_compat_ioctl,
.copy_file_range = ovl_copy_file_range,
.clone_file_range = ovl_clone_file_range,
.dedupe_file_range = ovl_dedupe_file_range,
}; };