[PATCH RESEND V11 1/7] fs: Generic function to convert iocb to rw flags

Alessio Balsini
2021-01-18T19:48:48Z

OverlayFS implements its own function to translate iocb flags into rw
flags, so that they can be passed into another vfs call.
With commit ce71bfea207b4 ("fs: align IOCB_* flags with RWF_* flags")
Jens created a 1:1 matching between the iocb flags and rw flags,
simplifying the conversion.

Reduce the OverlayFS code by making the flag conversion function generic
and reusable.

Signed-off-by: Alessio Balsini <balsini@android.com>
---
fs/overlayfs/file.c | 23 +++++------------------
include/linux/fs.h | 5 +++++
2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index bd9dd38347ae..56be2ffc5a14 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -15,6 +15,8 @@
#include <linux/fs.h>
#include "overlayfs.h"

+#define OVL_IOCB_MASK (IOCB_DSYNC | IOCB_HIPRI | IOCB_NOWAIT | IOCB_SYNC)
+
struct ovl_aio_req {
struct kiocb iocb;
struct kiocb *orig_iocb;
@@ -236,22 +238,6 @@ static void ovl_file_accessed(struct file *file)
touch_atime(&file->f_path);
}

-static rwf_t ovl_iocb_to_rwf(int ifl)
-{
- rwf_t flags = 0;
-
- if (ifl & IOCB_NOWAIT)
- flags |= RWF_NOWAIT;
- if (ifl & IOCB_HIPRI)
- flags |= RWF_HIPRI;
- if (ifl & IOCB_DSYNC)
- flags |= RWF_DSYNC;
- if (ifl & IOCB_SYNC)
- flags |= RWF_SYNC;
-
- return flags;
-}
-
static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
{
struct kiocb *iocb = &aio_req->iocb;
@@ -299,7 +285,8 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
old_cred = ovl_override_creds(file_inode(file)->i_sb);
if (is_sync_kiocb(iocb)) {
ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
- ovl_iocb_to_rwf(iocb->ki_flags));
+ iocb_to_rw_flags(iocb->ki_flags,
+ OVL_IOCB_MASK));
} else {
struct ovl_aio_req *aio_req;

@@ -356,7 +343,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
if (is_sync_kiocb(iocb)) {
file_start_write(real.file);
ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
- ovl_iocb_to_rwf(ifl));
+ iocb_to_rw_flags(ifl, OVL_IOCB_MASK));
file_end_write(real.file);
/* Update size */
ovl_copyattr(ovl_inode_real(inode), inode);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index fd47deea7c17..647c35423545 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3275,6 +3275,11 @@ static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
return 0;
}

+static inline rwf_t iocb_to_rw_flags(int ifl, int iocb_mask)
+{
+ return ifl & iocb_mask;
+}
+
static inline ino_t parent_ino(struct dentry *dentry)
{
ino_t res;