Re: [f2fs-dev] [bug report] compiler warning: fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: ‘head’ may be used uninitialized
On 2019/10/24 17:54, Ardelean, Alexandru wrote: > On Thu, 2019-10-24 at 17:12 +0800, Chao Yu wrote: >> [External] >> >> On 2019/10/23 22:02, Ardelean, Alexandru wrote: >>> Seems to have been introduced via: >>> >>> >>> >>> commit 780de47cf6cb5f524cd98ec8ffbffc3da5696e17 >>> Author: Chao Yu >>> Date: Tue Mar 20 23:08:30 2018 +0800 >>> >>> f2fs: don't track new nat entry in nat set >>> >>> Nat entry set is used only in checkpoint(), and during checkpoint() >>> we >>> won't flush new nat entry with unallocated address, so we don't >>> need to >>> add new nat entry into nat set, then nat_entry_set::entry_cnt can >>> indicate actual entry count we need to flush in checkpoint(). >>> >>> Signed-off-by: Yunlei He >>> Signed-off-by: Chao Yu >>> Signed-off-by: Jaegeuk Kim >>> >>> >>> Compiler warning is: >>> >>> >>> CC fs/f2fs/node.o >>> In file included from ./include/linux/wait.h:7:0, >>> from ./include/linux/wait_bit.h:8, >>> from ./include/linux/fs.h:6, >>> from fs/f2fs/node.c:11: >>> fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: >>> ./include/linux/list.h:63:13: error: ‘head’ may be used uninitialized >>> in >>> this function [-Werror=maybe-uninitialized] >>> next->prev = new; >>> ^ >>> fs/f2fs/node.c:238:24: note: ‘head’ was declared here >>> struct nat_entry_set *head; >> >> That's not correct, @head will only be assigned and used if new_ne equals >> NULL. > > Ack. > I admit that I don't understand the code, and don't claim to understand it. > > This may be just a weird compiler issue. > I thought I'd send it just as a heads-up. I think that's the right thing to do. > I saw this on a Raspberry Pi branch [after we enabled warnings as errors]: > https://travis-ci.org/analogdevicesinc/linux/jobs/601844926#L1208 > > Looking in the latest f2fs/dev[-test] tree, it looks like the code is > similar as in 4.19. > https://github.com/analogdevicesinc/linux/blob/rpi-4.19.y/fs/f2fs/node.c#L235 > > Could be that the RPi branch has some more compiler-stuff enabled. > > In any case, feel free to disregard this. > We will see how we fix this on our end for that branch specifically. That would make sense, let me know if you have any other suspicious compiler warnings. :) Thanks, > > Thanks > Alex > >> >> Thanks, >> >>> ^ >>> cc1: all warnings being treated as errors >>> >>> >>> Thanks >>> Alex >>> >>> ___ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >>> ___ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Re: [f2fs-dev] [bug report] compiler warning: fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: ‘head’ may be used uninitialized
On Thu, 2019-10-24 at 17:12 +0800, Chao Yu wrote: > [External] > > On 2019/10/23 22:02, Ardelean, Alexandru wrote: > > Seems to have been introduced via: > > > > > > > > commit 780de47cf6cb5f524cd98ec8ffbffc3da5696e17 > > Author: Chao Yu > > Date: Tue Mar 20 23:08:30 2018 +0800 > > > > f2fs: don't track new nat entry in nat set > > > > Nat entry set is used only in checkpoint(), and during checkpoint() > > we > > won't flush new nat entry with unallocated address, so we don't > > need to > > add new nat entry into nat set, then nat_entry_set::entry_cnt can > > indicate actual entry count we need to flush in checkpoint(). > > > > Signed-off-by: Yunlei He > > Signed-off-by: Chao Yu > > Signed-off-by: Jaegeuk Kim > > > > > > Compiler warning is: > > > > > > CC fs/f2fs/node.o > > In file included from ./include/linux/wait.h:7:0, > > from ./include/linux/wait_bit.h:8, > > from ./include/linux/fs.h:6, > > from fs/f2fs/node.c:11: > > fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: > > ./include/linux/list.h:63:13: error: ‘head’ may be used uninitialized > > in > > this function [-Werror=maybe-uninitialized] > > next->prev = new; > > ^ > > fs/f2fs/node.c:238:24: note: ‘head’ was declared here > > struct nat_entry_set *head; > > That's not correct, @head will only be assigned and used if new_ne equals > NULL. Ack. I admit that I don't understand the code, and don't claim to understand it. This may be just a weird compiler issue. I thought I'd send it just as a heads-up. I saw this on a Raspberry Pi branch [after we enabled warnings as errors]: https://travis-ci.org/analogdevicesinc/linux/jobs/601844926#L1208 Looking in the latest f2fs/dev[-test] tree, it looks like the code is similar as in 4.19. https://github.com/analogdevicesinc/linux/blob/rpi-4.19.y/fs/f2fs/node.c#L235 Could be that the RPi branch has some more compiler-stuff enabled. In any case, feel free to disregard this. We will see how we fix this on our end for that branch specifically. Thanks Alex > > Thanks, > > > ^ > > cc1: all warnings being treated as errors > > > > > > Thanks > > Alex > > > > ___ > > Linux-f2fs-devel mailing list > > Linux-f2fs-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > ___ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Re: [f2fs-dev] [bug report] compiler warning: fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: ‘head’ may be used uninitialized
On 2019/10/23 22:02, Ardelean, Alexandru wrote: > Seems to have been introduced via: > > > > commit 780de47cf6cb5f524cd98ec8ffbffc3da5696e17 > Author: Chao Yu > Date: Tue Mar 20 23:08:30 2018 +0800 > > f2fs: don't track new nat entry in nat set > > Nat entry set is used only in checkpoint(), and during checkpoint() we > won't flush new nat entry with unallocated address, so we don't need to > add new nat entry into nat set, then nat_entry_set::entry_cnt can > indicate actual entry count we need to flush in checkpoint(). > > Signed-off-by: Yunlei He > Signed-off-by: Chao Yu > Signed-off-by: Jaegeuk Kim > > > Compiler warning is: > > > CC fs/f2fs/node.o > In file included from ./include/linux/wait.h:7:0, > from ./include/linux/wait_bit.h:8, > from ./include/linux/fs.h:6, > from fs/f2fs/node.c:11: > fs/f2fs/node.c: In function ‘__set_nat_cache_dirty’: > ./include/linux/list.h:63:13: error: ‘head’ may be used uninitialized in > this function [-Werror=maybe-uninitialized] > next->prev = new; > ^ > fs/f2fs/node.c:238:24: note: ‘head’ was declared here > struct nat_entry_set *head; That's not correct, @head will only be assigned and used if new_ne equals NULL. Thanks, > ^ > cc1: all warnings being treated as errors > > > Thanks > Alex > > ___ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > ___ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
