fs: Add aio iopriority support

This is the per-I/O equivalent of the ioprio_set system call.

When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the
newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field.

This patch depends on block: add ioprio_check_cap function.

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 5d4e31655d9629732c42b02a602ebdc20bec2cda..dd98dfd97f5ea6029f49ca23152188d7d7348d84 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -76,6 +76,8 @@
 #include <linux/miscdevice.h>
 #include <linux/falloc.h>
 #include <linux/uio.h>
+#include <linux/ioprio.h>
+
 #include "loop.h"
 
 #include <linux/uaccess.h>
@@ -559,6 +561,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
        cmd->iocb.ki_filp = file;
        cmd->iocb.ki_complete = lo_rw_aio_complete;
        cmd->iocb.ki_flags = IOCB_DIRECT;
+       cmd->iocb.ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
        if (cmd->css)
                kthread_associate_blkcg(cmd->css);
 

diff --git a/fs/aio.c b/fs/aio.c
index 33299ece7540a86b274b70af852a3016b3b3c3e0..9527ededa66929ccf18bb456d5997b0dd9489bf0 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1435,6 +1435,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
        if (iocb->aio_flags & IOCB_FLAG_RESFD)
                req->ki_flags |= IOCB_EVENTFD;
        req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp));
+       if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
+               /*
+                * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
+                * aio_reqprio is interpreted as an I/O scheduling
+                * class and priority.
+                */
+               ret = ioprio_check_cap(iocb->aio_reqprio);
+               if (ret) {
+                       pr_debug("aio ioprio check cap error\n");
+                       return -EINVAL;
+               }
+
+               req->ki_ioprio = iocb->aio_reqprio;
+       } else
+               req->ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0);
+
        ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
        if (unlikely(ret))
                fput(req->ki_filp);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b432fc3feb93a2aeb713f4ce0db37b41068ed73a..eef9334b26d12d72d0539c8e04c58a530dc3c53c 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -36,6 +36,7 @@
 #include <linux/delayed_call.h>
 #include <linux/uuid.h>
 #include <linux/errseq.h>
+#include <linux/ioprio.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -300,6 +301,7 @@ struct kiocb {
        void                    *private;
        int                     ki_flags;
        u16                     ki_hint;
+       u16                     ki_ioprio; /* See linux/ioprio.h */
 } __randomize_layout;
 
 static inline bool is_sync_kiocb(struct kiocb *kiocb)
@@ -1944,6 +1946,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
                .ki_filp = filp,
                .ki_flags = iocb_flags(filp),
                .ki_hint = ki_hint_validate(file_write_hint(filp)),
+               .ki_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0),
        };
 }
 

diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index ed0185945bb2e8c23d8f7b0fc069f7c0babaf761..75846164290e9acaa9b2fbead09bdebc5422104c 100644 (file)
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -53,6 +53,7 @@ enum {
  *                   is valid.
  */
 #define IOCB_FLAG_RESFD                (1 << 0)
+#define IOCB_FLAG_IOPRIO       (1 << 1)
 
 /* read() from /dev/aio returns these structures. */
 struct io_event {