[PATCH 4/6] vfs: add the RWF_HIPRI flag for preadv2/pwritev2
STALE3798d
REVIEWED: 3 (0M)
From: Christoph Hellwig <hch@lst.de>
Date: 2016-03-03 15:04:13
Also in:
linux-api, linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
3 review trailers.
This adds a flag that tells the file system that this is a high priority request for which it's worth to poll the hardware. The flag is purely advisory and can be ignored if not supported. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stephen Bates <redacted> Tested-by: Stephen Bates <redacted> Acked-by: Jeff Moyer <redacted> --- fs/read_write.c | 6 ++++-- include/linux/fs.h | 1 + include/uapi/linux/fs.h | 3 +++ 3 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 799d25f..cf377cf 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c@@ -698,10 +698,12 @@ static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter, struct kiocb kiocb; ssize_t ret; - if (flags) + if (flags & ~RWF_HIPRI) return -EOPNOTSUPP; init_sync_kiocb(&kiocb, filp); + if (flags & RWF_HIPRI) + kiocb.ki_flags |= IOCB_HIPRI; kiocb.ki_pos = *ppos; ret = fn(&kiocb, iter);
@@ -716,7 +718,7 @@ static ssize_t do_loop_readv_writev(struct file *filp, struct iov_iter *iter, { ssize_t ret = 0; - if (flags) + if (flags & ~RWF_HIPRI) return -EOPNOTSUPP; while (iov_iter_count(iter)) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 875277a..a1f731c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -320,6 +320,7 @@ struct writeback_control; #define IOCB_EVENTFD (1 << 0) #define IOCB_APPEND (1 << 1) #define IOCB_DIRECT (1 << 2) +#define IOCB_HIPRI (1 << 3) struct kiocb { struct file *ki_filp;
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 149bec8..d246339 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h@@ -304,4 +304,7 @@ struct fsxattr { #define SYNC_FILE_RANGE_WRITE 2 #define SYNC_FILE_RANGE_WAIT_AFTER 4 +/* flags for preadv2/pwritev2: */ +#define RWF_HIPRI 0x00000001 /* high priority request, poll if possible */ + #endif /* _UAPI_LINUX_FS_H */
--
2.1.4