Patch "gfs2: avoid uninitialized variable warning" has been added to the 3.18-stable tree

Patch "gfs2: avoid uninitialized variable warning" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    gfs2: avoid uninitialized variable warning

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     gfs2-avoid-uninitialized-variable-warning.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 67893f12e5374bbcaaffbc6e570acbc2714ea884 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Tue, 26 Jan 2016 13:08:10 -0500
Subject: gfs2: avoid uninitialized variable warning

From: Arnd Bergmann <arnd@arndb.de>

commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 upstream.

We get a bogus warning about a potential uninitialized variable
use in gfs2, because the compiler does not figure out that we
never use the leaf number if get_leaf_nr() returns an error:

fs/gfs2/dir.c: In function 'get_first_leaf':
fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/gfs2/dir.c: In function 'dir_split_leaf':
fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]

Changing the 'if (!error)' to 'if (!IS_ERR_VALUE(error))' is
sufficient to let gcc understand that this is exactly the same
condition as in IS_ERR() so it can optimize the code path enough
to understand it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/gfs2/dir.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -764,7 +764,7 @@ static int get_first_leaf(struct gfs2_in
 	int error;
 
 	error = get_leaf_nr(dip, index, &leaf_no);
-	if (!error)
+	if (!IS_ERR_VALUE(error))
 		error = get_leaf(dip, leaf_no, bh_out);
 
 	return error;
@@ -980,7 +980,7 @@ static int dir_split_leaf(struct inode *
 
 	index = name->hash >> (32 - dip->i_depth);
 	error = get_leaf_nr(dip, index, &leaf_no);
-	if (error)
+	if (IS_ERR_VALUE(error))
 		return error;
 
 	/*  Get the old leaf block  */


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-3.18/net-vxge-avoid-unused-function-warnings.patch
queue-3.18/tty-nozomi-avoid-a-harmless-gcc-warning.patch
queue-3.18/perf-avoid-horrible-stack-usage.patch
queue-3.18/btrfs-fix-state-private-cast-on-32-bit-machines.patch
queue-3.18/mm-init-fix-zone-boundary-creation.patch
queue-3.18/iommu-vt-d-remove-unused-variable.patch
queue-3.18/mips-msp71xx-remove-odd-locking-in-pci-config-space-access-code.patch
queue-3.18/net-tulip-turn-compile-time-warning-into-dev_warn.patch
queue-3.18/nfsd-work-around-a-gcc-5.1-warning.patch
queue-3.18/fs-nfs-fix-new-compiler-warning-about-boolean-in-switch.patch
queue-3.18/aic94xx-skip-reading-user-settings-if-flash-is-not-found.patch
queue-3.18/mmc-sunxi-avoid-invalid-pointer-calculation.patch
queue-3.18/acpi-power-avoid-maybe-uninitialized-warning.patch
queue-3.18/gfs2-avoid-uninitialized-variable-warning.patch
queue-3.18/gadgetfs-fix-uninitialized-variable-in-error-handling.patch
queue-3.18/arm-8296-1-cache-l2x0-clean-up-aurora-cache-handling.patch
queue-3.18/brcmfmac-avoid-gcc-5.1-warning.patch
queue-3.18/kconfig-tinyconfig-provide-whole-choice-blocks-to-avoid-warnings.patch
queue-3.18/net-ti-cpmac-fix-compiler-warning-due-to-type-confusion.patch
queue-3.18/clk-at91-usb-fix-determine_rate-prototype-again.patch
queue-3.18/mips-ralink-cosmetic-change-to-prom_init.patch
queue-3.18/mips-fix-the-build-on-jz4740-after-removing-the-custom-gpio.h.patch
queue-3.18/mips-asm-compiler-add-new-macros-to-set-isa-and-arch-asm-annotations.patch
queue-3.18/misc-ioc4-simplify-wave-period-measurement-in-clock_calibrate.patch
queue-3.18/hostap-avoid-uninitialized-variable-use-in-hfa384x_get_rid.patch
queue-3.18/dm-bufio-hide-bogus-warning.patch
queue-3.18/fix-signed-unsigned-pointer-warning.patch