| Message ID | 1604922436-16597-1-git-send-email-alex.shi@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [REF] mm/swap: fix swapon failure | expand |
On Mon, Nov 09, 2020 at 07:47:16PM +0800, Alex Shi wrote: > Go through the context I found the exit_swap_address_space(p->type) > shouldn't be used in good result path. So just move it to error path. But ... it's not used in the success path. There's a 'goto' right before it. Does this really fix your problem? > @@ -3339,7 +3339,8 @@ static bool swap_discardable(struct swap_info_struct *si) > error = inode_drain_writes(inode); > if (error) { > inode->i_flags &= ~S_SWAPFILE; > - goto free_swap_address_space; > + exit_swap_address_space(p->type); > + goto bad_swap_unlock_inode; > } > > mutex_lock(&swapon_mutex); > @@ -3364,8 +3365,6 @@ static bool swap_discardable(struct swap_info_struct *si) > > error = 0; > goto out; > -free_swap_address_space: > - exit_swap_address_space(p->type); > bad_swap_unlock_inode: > inode_unlock(inode); > bad_swap: > -- > 1.8.3.1 > >
在 2020/11/9 下午8:07, Matthew Wilcox 写道: > On Mon, Nov 09, 2020 at 07:47:16PM +0800, Alex Shi wrote: >> Go through the context I found the exit_swap_address_space(p->type) >> shouldn't be used in good result path. So just move it to error path. > > But ... it's not used in the success path. There's a 'goto' right > before it. Does this really fix your problem? > The trick thing is. It do fix my problem on my centos 7 with gcc 8.3.1... I am getting headache on this problem... >> @@ -3339,7 +3339,8 @@ static bool swap_discardable(struct swap_info_struct *si) >> error = inode_drain_writes(inode); >> if (error) { >> inode->i_flags &= ~S_SWAPFILE; >> - goto free_swap_address_space; >> + exit_swap_address_space(p->type); >> + goto bad_swap_unlock_inode; >> } >> >> mutex_lock(&swapon_mutex); >> @@ -3364,8 +3365,6 @@ static bool swap_discardable(struct swap_info_struct *si) >> >> error = 0; >> goto out; >> -free_swap_address_space: >> - exit_swap_address_space(p->type); >> bad_swap_unlock_inode: >> inode_unlock(inode); >> bad_swap: >> -- >> 1.8.3.1 >> >>
在 2020/11/9 下午8:17, Alex Shi 写道: > > > 在 2020/11/9 下午8:07, Matthew Wilcox 写道: >> On Mon, Nov 09, 2020 at 07:47:16PM +0800, Alex Shi wrote: >>> Go through the context I found the exit_swap_address_space(p->type) >>> shouldn't be used in good result path. So just move it to error path. >> >> But ... it's not used in the success path. There's a 'goto' right >> before it. Does this really fix your problem? >> > > The trick thing is. It do fix my problem on my centos 7 with gcc 8.3.1... > > I am getting headache on this problem... Checked again on my git tree. nothing weird, and code based on cf7cd542d1b5 Add linux-next specific files for 20201104 Sorry, I have no idea where is the problem... > >>> @@ -3339,7 +3339,8 @@ static bool swap_discardable(struct swap_info_struct *si) >>> error = inode_drain_writes(inode); >>> if (error) { >>> inode->i_flags &= ~S_SWAPFILE; >>> - goto free_swap_address_space; >>> + exit_swap_address_space(p->type); >>> + goto bad_swap_unlock_inode; >>> } >>> >>> mutex_lock(&swapon_mutex); >>> @@ -3364,8 +3365,6 @@ static bool swap_discardable(struct swap_info_struct *si) >>> >>> error = 0; >>> goto out; >>> -free_swap_address_space: >>> - exit_swap_address_space(p->type); >>> bad_swap_unlock_inode: >>> inode_unlock(inode); >>> bad_swap: >>> -- >>> 1.8.3.1 >>> >>>
diff --git a/mm/swapfile.c b/mm/swapfile.c index c8966b8fc6ac..1ac1f737fee3 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3339,7 +3339,8 @@ static bool swap_discardable(struct swap_info_struct *si) error = inode_drain_writes(inode); if (error) { inode->i_flags &= ~S_SWAPFILE; - goto free_swap_address_space; + exit_swap_address_space(p->type); + goto bad_swap_unlock_inode; } mutex_lock(&swapon_mutex); @@ -3364,8 +3365,6 @@ static bool swap_discardable(struct swap_info_struct *si) error = 0; goto out; -free_swap_address_space: - exit_swap_address_space(p->type); bad_swap_unlock_inode: inode_unlock(inode); bad_swap:
One of my VM guest has a swapon issue: root #swapon -v -f /swap1 swapon /swap1 swapon: /swap1: found swap signature: version 1, page-size 4, same byte order swapon: /swap1: pagesize=4096, swapsize=1607467008, devsize=1607467008 swapon: /swap1: swapon failed: Invalid argument and bisection report commit 822bca52ee7e "mm/swapfile.c: fix potential memory leak in sys_swapon" cause the trouble. Go through the context I found the exit_swap_address_space(p->type) shouldn't be used in good result path. So just move it to error path. Fixes: 822bca52ee7e ("mm/swapfile.c: fix potential memory leak in sys_swapon") Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/swapfile.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)