From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Allow the clone and dedupe prep function to shorten the request if the
caller can handle it.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/read_write.c | 8 ++------
include/linux/fs.h | 2 +-
mm/filemap.c | 19 +++++++++++++++----
3 files changed, 18 insertions(+), 11 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 4eaea52f70a8..292d68c2f47c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1726,7 +1726,6 @@ int vfs_clone_file_prep(struct file *file_in, loff_t pos_in,
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
- uint64_t nlen;
loff_t isize;
bool same_inode = (inode_in == inode_out);
bool is_dedupe = (flags & CLONERANGE_DEDUPE);
@@ -1758,13 +1757,10 @@ int vfs_clone_file_prep(struct file *file_in, loff_t pos_in,
}
/* Check that we don't violate system file offset limits. */
- nlen = *len;
- ret = generic_clone_checks(file_in, pos_in, file_out, pos_out, &nlen,
- is_dedupe);
+ ret = generic_clone_checks(file_in, pos_in, file_out, pos_out, len,
+ flags);
if (ret)
return ret;
- if (nlen != *len)
- return -EINVAL;
/* Wait for the completion of any pending IOs on both files */
inode_dio_wait(inode_in);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ae5685c31270..eb35363478e5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2988,7 +2988,7 @@ extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
extern int generic_clone_checks(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- uint64_t *count, bool is_dedupe);
+ uint64_t *count, unsigned int flags);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
diff --git a/mm/filemap.c b/mm/filemap.c
index f74391721234..013451b8017f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2983,7 +2983,7 @@ EXPORT_SYMBOL(generic_write_checks);
*/
int generic_clone_checks(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
- uint64_t *req_count, bool is_dedupe)
+ uint64_t *req_count, unsigned int flags)
{
struct inode *inode_in = file_in->f_mapping->host;
struct inode *inode_out = file_out->f_mapping->host;
@@ -3005,7 +3005,7 @@ int generic_clone_checks(struct file *file_in, loff_t pos_in,
size_out = i_size_read(inode_out);
/* Dedupe requires both ranges to be within EOF. */
- if (is_dedupe &&
+ if ((flags & CLONERANGE_DEDUPE) &&
(pos_in >= size_in || pos_in + count > size_in ||
pos_out >= size_out || pos_out + count > size_out))
return -EINVAL;
@@ -3056,8 +3056,12 @@ int generic_clone_checks(struct file *file_in, loff_t pos_in,
if (pos_in + count == size_in) {
bcount = ALIGN(size_in, bs) - pos_in;
} else {
- if (!IS_ALIGNED(count, bs))
- return -EINVAL;
+ if (!IS_ALIGNED(count, bs)) {
+ if (flags & CLONERANGE_SHORT)
+ count = ALIGN_DOWN(count, bs);
+ else
+ return -EINVAL;
+ }
bcount = count;
}
@@ -3068,6 +3072,13 @@ int generic_clone_checks(struct file *file_in, loff_t pos_in,
pos_out < pos_in + bcount)
return -EINVAL;
+ /*
+ * We shortened the request but the caller can't deal with that, so
+ * bounce the request back to userspace.
+ */
+ if (*req_count != count && !(flags & CLONERANGE_SHORT))
+ return -EINVAL;
+
*req_count = count;
return 0;
}
