There is not much in those helpers, but it makes sense to have them
logically next to the backing_file_{read,write}_iter() helpers as they
may grow more common logic in the future.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
fs/backing-file.c | 45 ++++++++++++++++++++++++++++++++++++
fs/overlayfs/file.c | 33 +++++++++++---------------
include/linux/backing-file.h | 8 +++++++
3 files changed, 66 insertions(+), 20 deletions(-)
diff --git a/fs/backing-file.c b/fs/backing-file.c
index c1976ef5c210..46488de821a2 100644
--- a/fs/backing-file.c
+++ b/fs/backing-file.c
@@ -10,6 +10,7 @@
#include <linux/fs.h>
#include <linux/backing-file.h>
+#include <linux/splice.h>
#include "internal.h"
@@ -239,6 +240,50 @@ ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
}
EXPORT_SYMBOL_GPL(backing_file_write_iter);
+ssize_t backing_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx)
+{
+ const struct cred *old_cred;
+ ssize_t ret;
+
+ old_cred = override_creds(ctx->cred);
+ ret = vfs_splice_read(in, ppos, pipe, len, flags);
+ revert_creds(old_cred);
+
+ if (ctx->accessed)
+ ctx->accessed(ctx->user_file);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(backing_file_splice_read);
+
+ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *out, loff_t *ppos, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx)
+{
+ const struct cred *old_cred;
+ ssize_t ret;
+
+ ret = file_remove_privs(ctx->user_file);
+ if (ret)
+ return ret;
+
+ old_cred = override_creds(ctx->cred);
+ file_start_write(out);
+ ret = iter_file_splice_write(pipe, out, ppos, len, flags);
+ file_end_write(out);
+ revert_creds(old_cred);
+
+ if (ctx->end_write)
+ ctx->end_write(ctx->user_file);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(backing_file_splice_write);
+
static int __init backing_aio_init(void)
{
backing_aio_cachep = kmem_cache_create("backing_aio",
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 1b578cb27a26..69b52d2f9c74 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -9,7 +9,6 @@
#include <linux/xattr.h>
#include <linux/uio.h>
#include <linux/uaccess.h>
-#include <linux/splice.h>
#include <linux/security.h>
#include <linux/mm.h>
#include <linux/fs.h>
@@ -332,20 +331,21 @@ static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
- const struct cred *old_cred;
struct fd real;
ssize_t ret;
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(file_inode(in)->i_sb),
+ .user_file = in,
+ .accessed = ovl_file_accessed,
+ };
ret = ovl_real_fdget(in, &real);
if (ret)
return ret;
- old_cred = ovl_override_creds(file_inode(in)->i_sb);
- ret = vfs_splice_read(real.file, ppos, pipe, len, flags);
- revert_creds(old_cred);
- ovl_file_accessed(in);
-
+ ret = backing_file_splice_read(real.file, ppos, pipe, len, flags, &ctx);
fdput(real);
+
return ret;
}
@@ -361,30 +361,23 @@ static ssize_t ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
struct fd real;
- const struct cred *old_cred;
struct inode *inode = file_inode(out);
ssize_t ret;
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(inode->i_sb),
+ .user_file = out,
+ .end_write = ovl_file_modified,
+ };
inode_lock(inode);
/* Update mode */
ovl_copyattr(inode);
- ret = file_remove_privs(out);
- if (ret)
- goto out_unlock;
ret = ovl_real_fdget(out, &real);
if (ret)
goto out_unlock;
- old_cred = ovl_override_creds(inode->i_sb);
- file_start_write(real.file);
-
- ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
-
- file_end_write(real.file);
- /* Update size */
- ovl_file_modified(out);
- revert_creds(old_cred);
+ ret = backing_file_splice_write(pipe, real.file, ppos, len, flags, &ctx);
fdput(real);
out_unlock:
diff --git a/include/linux/backing-file.h b/include/linux/backing-file.h
index 0648d548a418..0546d5b1c9f5 100644
--- a/include/linux/backing-file.h
+++ b/include/linux/backing-file.h
@@ -28,5 +28,13 @@ ssize_t backing_file_read_iter(struct file *file, struct iov_iter *iter,
ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter,
struct kiocb *iocb, int flags,
struct backing_file_ctx *ctx);
+ssize_t backing_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx);
+ssize_t backing_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *out, loff_t *ppos, size_t len,
+ unsigned int flags,
+ struct backing_file_ctx *ctx);
#endif /* _LINUX_BACKING_FILE_H */
--
2.34.1
