From: gregkh@linuxfoundation.org
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
David Sterba <dsterba@suse.com>
Subject: [PATCH 4.14 01/20] btrfs: raid56: simplify tracking of Q stripe presence
Date: Wed, 10 Mar 2021 14:24:38 +0100 [thread overview]
Message-ID: <20210310132320.559756662@linuxfoundation.org> (raw)
In-Reply-To: <20210310132320.512307035@linuxfoundation.org>
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: David Sterba <dsterba@suse.com>
commit c17af96554a8a8777cbb0fd53b8497250e548b43 upstream.
There are temporary variables tracking the index of P and Q stripes, but
none of them is really used as such, merely for determining if the Q
stripe is present. This leads to compiler warnings with
-Wunused-but-set-variable and has been reported several times.
fs/btrfs/raid56.c: In function ‘finish_rmw’:
fs/btrfs/raid56.c:1199:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
1199 | int p_stripe = -1;
| ^~~~~~~~
fs/btrfs/raid56.c: In function ‘finish_parity_scrub’:
fs/btrfs/raid56.c:2356:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
2356 | int p_stripe = -1;
| ^~~~~~~~
Replace the two variables with one that has a clear meaning and also get
rid of the warnings. The logic that verifies that there are only 2
valid cases is unchanged.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/raid56.c | 37 +++++++++++++++----------------------
1 file changed, 15 insertions(+), 22 deletions(-)
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1190,22 +1190,19 @@ static noinline void finish_rmw(struct b
int nr_data = rbio->nr_data;
int stripe;
int pagenr;
- int p_stripe = -1;
- int q_stripe = -1;
+ bool has_qstripe;
struct bio_list bio_list;
struct bio *bio;
int ret;
bio_list_init(&bio_list);
- if (rbio->real_stripes - rbio->nr_data == 1) {
- p_stripe = rbio->real_stripes - 1;
- } else if (rbio->real_stripes - rbio->nr_data == 2) {
- p_stripe = rbio->real_stripes - 2;
- q_stripe = rbio->real_stripes - 1;
- } else {
+ if (rbio->real_stripes - rbio->nr_data == 1)
+ has_qstripe = false;
+ else if (rbio->real_stripes - rbio->nr_data == 2)
+ has_qstripe = true;
+ else
BUG();
- }
/* at this point we either have a full stripe,
* or we've read the full stripe from the drive.
@@ -1249,7 +1246,7 @@ static noinline void finish_rmw(struct b
SetPageUptodate(p);
pointers[stripe++] = kmap(p);
- if (q_stripe != -1) {
+ if (has_qstripe) {
/*
* raid6, add the qstripe and call the
@@ -2325,8 +2322,7 @@ static noinline void finish_parity_scrub
int nr_data = rbio->nr_data;
int stripe;
int pagenr;
- int p_stripe = -1;
- int q_stripe = -1;
+ bool has_qstripe;
struct page *p_page = NULL;
struct page *q_page = NULL;
struct bio_list bio_list;
@@ -2336,14 +2332,12 @@ static noinline void finish_parity_scrub
bio_list_init(&bio_list);
- if (rbio->real_stripes - rbio->nr_data == 1) {
- p_stripe = rbio->real_stripes - 1;
- } else if (rbio->real_stripes - rbio->nr_data == 2) {
- p_stripe = rbio->real_stripes - 2;
- q_stripe = rbio->real_stripes - 1;
- } else {
+ if (rbio->real_stripes - rbio->nr_data == 1)
+ has_qstripe = false;
+ else if (rbio->real_stripes - rbio->nr_data == 2)
+ has_qstripe = true;
+ else
BUG();
- }
if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) {
is_replace = 1;
@@ -2365,7 +2359,7 @@ static noinline void finish_parity_scrub
goto cleanup;
SetPageUptodate(p_page);
- if (q_stripe != -1) {
+ if (has_qstripe) {
q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
if (!q_page) {
__free_page(p_page);
@@ -2388,8 +2382,7 @@ static noinline void finish_parity_scrub
/* then add the parity stripe */
pointers[stripe++] = kmap(p_page);
- if (q_stripe != -1) {
-
+ if (has_qstripe) {
/*
* raid6, add the qstripe and call the
* library function to fill in our p/q
next prev parent reply other threads:[~2021-03-10 13:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-10 13:24 [PATCH 4.14 00/20] 4.14.225-rc1 review gregkh
2021-03-10 13:24 ` gregkh [this message]
2021-03-10 13:24 ` [PATCH 4.14 02/20] btrfs: fix raid6 qstripe kmap gregkh
2021-03-10 13:24 ` [PATCH 4.14 03/20] PM: runtime: Update device status before letting suppliers suspend gregkh
2021-03-10 13:24 ` [PATCH 4.14 04/20] usbip: tools: fix build error for multiple definition gregkh
2021-03-10 13:24 ` [PATCH 4.14 05/20] ALSA: ctxfi: cthw20k2: fix mask on conf to allow 4 bits gregkh
2021-03-10 13:24 ` [PATCH 4.14 06/20] rsxx: Return -EFAULT if copy_to_user() fails gregkh
2021-03-10 13:24 ` [PATCH 4.14 07/20] dm table: fix iterate_devices based device capability checks gregkh
2021-03-10 13:24 ` [PATCH 4.14 08/20] dm table: fix DAX " gregkh
2021-03-10 13:24 ` [PATCH 4.14 09/20] dm table: fix zoned " gregkh
2021-03-10 13:24 ` [PATCH 4.14 10/20] iommu/amd: Fix sleeping in atomic in increase_address_space() gregkh
2021-03-10 13:24 ` [PATCH 4.14 11/20] mwifiex: pcie: skip cancel_work_sync() on reset failure path gregkh
2021-03-10 13:24 ` [PATCH 4.14 12/20] platform/x86: acer-wmi: Cleanup ACER_CAP_FOO defines gregkh
2021-03-10 13:24 ` [PATCH 4.14 13/20] platform/x86: acer-wmi: Cleanup accelerometer device handling gregkh
2021-03-10 13:24 ` [PATCH 4.14 14/20] platform/x86: acer-wmi: Add new force_caps module parameter gregkh
2021-03-10 13:24 ` [PATCH 4.14 15/20] platform/x86: acer-wmi: Add ACER_CAP_SET_FUNCTION_MODE capability flag gregkh
2021-03-10 13:24 ` [PATCH 4.14 16/20] platform/x86: acer-wmi: Add support for SW_TABLET_MODE on Switch devices gregkh
2021-03-10 13:24 ` [PATCH 4.14 17/20] platform/x86: acer-wmi: Add ACER_CAP_KBD_DOCK quirk for the Aspire Switch 10E SW3-016 gregkh
2021-03-10 13:24 ` [PATCH 4.14 18/20] PCI: Add function 1 DMA alias quirk for Marvell 9215 SATA controller gregkh
2021-03-10 13:24 ` [PATCH 4.14 19/20] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom gregkh
2021-03-10 13:24 ` [PATCH 4.14 20/20] drm/msm/a5xx: Remove overwriting A5XX_PC_DBG_ECO_CNTL register gregkh
2021-03-10 23:51 ` [PATCH 4.14 00/20] 4.14.225-rc1 review Guenter Roeck
2021-03-11 8:30 ` Naresh Kamboju
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