Since there are applications (e.g. Ceph) that use F_[GS]ET_FILE_RW_HINT,
restore support for these fcntls. This patch restores functionality that
was removed by commit 7b12e49669c9 ("fs: remove fs.f_write_hint").
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
fs/fcntl.c | 37 +++++++++++++++++++++++++++++++++++++
fs/open.c | 1 +
include/linux/fs.h | 9 +++++++++
3 files changed, 47 insertions(+)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index fc73c5fae43c..8018c4da478c 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -322,6 +322,37 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
return 0;
}
+static long fcntl_get_file_rw_hint(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file_inode(file);
+ u64 __user *argp = (u64 __user *)arg;
+ u64 hint = inode->i_write_hint;
+
+ hint = file_write_hint(file);
+ if (copy_to_user(argp, &hint, sizeof(*argp)))
+ return -EFAULT;
+ return 0;
+}
+
+static long fcntl_set_file_rw_hint(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ u64 __user *argp = (u64 __user *)arg;
+ u64 hint;
+
+ if (copy_from_user(&hint, argp, sizeof(hint)))
+ return -EFAULT;
+ if (!rw_hint_valid(hint))
+ return -EINVAL;
+
+ spin_lock(&file->f_lock);
+ file->f_write_hint = hint;
+ spin_unlock(&file->f_lock);
+
+ return 0;
+}
+
static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
struct file *filp)
{
@@ -430,6 +461,12 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
case F_SET_RW_HINT:
err = fcntl_set_rw_hint(filp, cmd, arg);
break;
+ case F_GET_FILE_RW_HINT:
+ err = fcntl_get_file_rw_hint(filp, cmd, arg);
+ break;
+ case F_SET_FILE_RW_HINT:
+ err = fcntl_set_file_rw_hint(filp, cmd, arg);
+ break;
default:
break;
}
diff --git a/fs/open.c b/fs/open.c
index 02dc608d40d8..4c5c29541ac5 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -961,6 +961,7 @@ static int do_dentry_open(struct file *f,
if (f->f_mapping->a_ops && f->f_mapping->a_ops->direct_IO)
f->f_mode |= FMODE_CAN_ODIRECT;
+ f->f_write_hint = WRITE_LIFE_NOT_SET;
f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
f->f_iocb_flags = iocb_flags(f);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a08014b68d6e..a6e0c4b5a72b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -989,6 +989,7 @@ struct file {
* Must not be taken from IRQ context.
*/
spinlock_t f_lock;
+ enum rw_hint f_write_hint;
fmode_t f_mode;
atomic_long_t f_count;
struct mutex f_pos_lock;
@@ -2162,6 +2163,14 @@ static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap,
!vfsgid_valid(i_gid_into_vfsgid(idmap, inode));
}
+static inline enum rw_hint file_write_hint(struct file *file)
+{
+ if (file->f_write_hint != WRITE_LIFE_NOT_SET)
+ return file->f_write_hint;
+
+ return file_inode(file)->i_write_hint;
+}
+
static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
{
*kiocb = (struct kiocb) {
