diff options
| author | Christoph Hellwig <hch@lst.de> | 2016-03-03 18:04:01 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-03-04 20:20:10 +0300 |
| commit | 97be7ebe53915af504fb491fb99f064c7cf3cb09 (patch) | |
| tree | bf2995e974c538c38d5db5c4fbf9486cce478d81 | |
| parent | 4babf2c5efb79be778d45ebe95d9c9b3c880c83b (diff) | |
| download | linux-97be7ebe53915af504fb491fb99f064c7cf3cb09.tar.xz | |
vfs: add the RWF_HIPRI flag for preadv2/pwritev2
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 <stephen.bates@pmcs.com>
Tested-by: Stephen Bates <stephen.bates@pmcs.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/read_write.c | 6 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 | ||||
| -rw-r--r-- | 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 e9c9e2a667ce..07c53db04ec1 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -697,10 +697,12 @@ 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); @@ -715,7 +717,7 @@ 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 6ec87964644f..337de88ff50f 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 41e0433b4a83..847c656729f8 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -305,4 +305,7 @@ 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 */ |