Archive-Team
/
zfs
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 103 Wiki Activity

Reintroduce IO accounting on zvols on Linux 3.19+ 

zfsonlinux/zfs@e20cd6f7a8 caused us to
lose IO accounting on zvols. When I originally wrote that last year, the
symbols we needed to maintain IO accounting were GPL exported, but
torvalds/linux@394ffa503b provided
suitable symbols for restoring this functionality 4 months later.  We
can call them to restore the IO accounting on Linux 3.19 and later as
well as any older kernels where that patch is backported.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3741
This commit is contained in:
Richard Yao 2015-09-07 12:03:19 -04:00 committed by Brian Behlendorf
parent 1e17e910ea
commit 8198d18ca7
4 changed files with 45 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
config/kernel-generic_io_acct.m4 Normal file
View File

@ -0,0 +1,26 @@
dnl #
dnl # 3.19 API addition
dnl #
dnl # torvalds/linux@394ffa503bc40e32d7f54a9b817264e81ce131b4 allows us to
dnl # increment iostat counters without generic_make_request().
dnl #
AC_DEFUN([ZFS_AC_KERNEL_GENERIC_IO_ACCT], [
AC_MSG_CHECKING([whether generic IO accounting symbols are avaliable])
ZFS_LINUX_TRY_COMPILE_SYMBOL([
#include <linux/bio.h>
void (*generic_start_io_acct_f)(int, unsigned long,
struct hd_struct *) = &generic_start_io_acct;
void (*generic_end_io_acct_f)(int, struct hd_struct *,
unsigned long) = &generic_end_io_acct;
], [
generic_start_io_acct(0, 0, NULL);
generic_end_io_acct(0, NULL, 0);
], [generic_start_io_acct], [block/bio.c], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_GENERIC_IO_ACCT, 1,
[generic_start_io_acct()/generic_end_io_acct() avaliable])
], [
AC_MSG_RESULT(no)
])
])

1
config/kernel.m4
View File

@ -94,6 +94,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL_KMAP_ATOMIC_ARGS
ZFS_AC_KERNEL_FOLLOW_DOWN_ONE
ZFS_AC_KERNEL_MAKE_REQUEST_FN
ZFS_AC_KERNEL_GENERIC_IO_ACCT
AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"

5
include/linux/blkdev_compat.h
View File

@ -343,4 +343,9 @@ blk_queue_discard_granularity(struct request_queue *q, unsigned int dg)
*/
#define VDEV_HOLDER ((void *)0x2401de7)
#ifndef HAVE_GENERIC_IO_ACCT
#define generic_start_io_acct(rw, slen, part) ((void)0)
#define generic_end_io_acct(rw, part, start_jiffies) ((void)0)
#endif
#endif /* _ZFS_BLKDEV_H */

18
module/zfs/zvol.c
View File

@ -713,6 +713,10 @@ zvol_request(struct request_queue *q, struct bio *bio)
fstrans_cookie_t cookie = spl_fstrans_mark();
uint64_t offset = BIO_BI_SECTOR(bio);
unsigned int sectors = bio_sectors(bio);
int rw = bio_data_dir(bio);
#ifdef HAVE_GENERIC_IO_ACCT
unsigned long start = jiffies;
#endif
int error = 0;
if (bio_has_data(bio) && offset + sectors >
@ -723,25 +727,29 @@ zvol_request(struct request_queue *q, struct bio *bio)
(long long unsigned)offset,
(long unsigned)sectors);
error = SET_ERROR(EIO);
goto out;
goto out1;
}
if (bio_data_dir(bio) == WRITE) {
generic_start_io_acct(rw, sectors, &zv->zv_disk->part0);
if (rw == WRITE) {
if (unlikely(zv->zv_flags & ZVOL_RDONLY)) {
error = SET_ERROR(EROFS);
goto out;
goto out2;
}
if (bio->bi_rw & VDEV_REQ_DISCARD) {
error = zvol_discard(bio);
goto out;
goto out2;
}
error = zvol_write(bio);
} else
error = zvol_read(bio);
out:
out2:
generic_end_io_acct(rw, &zv->zv_disk->part0, start);
out1:
bio_endio(bio, -error);
spl_fstrans_unmark(cookie);
#ifdef HAVE_MAKE_REQUEST_FN_RET_INT