Write hints applied with F_SET_RW_HINT on a block device affect the shmem inode only. Propagate these hints to the block device inode because that is the inode used when writing back dirty pages. Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Jeff Layton <jlayton@xxxxxxxxxx> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx> --- block/fops.c | 11 +++++++++++ fs/fcntl.c | 4 ++++ include/linux/fs.h | 1 + 3 files changed, 16 insertions(+) diff --git a/block/fops.c b/block/fops.c index 2de61d81f8ec..87ddaf3ac831 100644 --- a/block/fops.c +++ b/block/fops.c @@ -620,6 +620,16 @@ static int blkdev_release(struct inode *inode, struct file *filp) return 0; } +static void blkdev_apply_whint(struct file *file, enum rw_hint hint) +{ + struct bdev_handle *handle = file->private_data; + struct inode *bd_inode = handle->bdev->bd_inode; + + inode_lock(bd_inode); + bd_inode->i_write_hint = hint; + inode_unlock(bd_inode); +} + static ssize_t blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) { @@ -854,6 +864,7 @@ const struct file_operations def_blk_fops = { .splice_read = filemap_splice_read, .splice_write = iter_file_splice_write, .fallocate = blkdev_fallocate, + .apply_whint = blkdev_apply_whint, }; static __init int blkdev_init(void) diff --git a/fs/fcntl.c b/fs/fcntl.c index fe80e19f1c1a..c0f8b7e880a4 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -287,6 +287,7 @@ static bool rw_hint_valid(u64 hint) static long fcntl_rw_hint(struct file *file, unsigned int cmd, unsigned long arg) { + void (*apply_whint)(struct file *, enum rw_hint); struct inode *inode = file_inode(file); u64 __user *argp = (u64 __user *)arg; u64 hint; @@ -320,6 +321,9 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd, inode_lock(inode); inode->i_write_hint = hint; + apply_whint = inode->i_fop->apply_whint; + if (apply_whint) + apply_whint(file, hint); inode_unlock(inode); return 0; default: diff --git a/include/linux/fs.h b/include/linux/fs.h index acc0cbab93dd..c5f82b88a82e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1946,6 +1946,7 @@ struct file_operations { int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags); int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *, unsigned int poll_flags); + void (*apply_whint)(struct file *, enum rw_hint hint); } __randomize_layout; /* Wrap a directory iterator that needs exclusive inode access */