diff options
| author | Omar Sandoval <osandov@fb.com> | 2018-05-25 23:47:17 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-26 03:12:10 +0200 |
| commit | 7cbf319234adaa4518a28c8c523d3330e06638f0 (patch) | |
| tree | c25ce860d1ba8ac686456d181acca73048d3a1a5 | |
| parent | Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm6... (diff) | |
| download | linux-7cbf319234adaa4518a28c8c523d3330e06638f0.tar.xz linux-7cbf319234adaa4518a28c8c523d3330e06638f0.zip | |
mm: fix nr_rotate_swap leak in swapon() error case
If swapon() fails after incrementing nr_rotate_swap, we don't decrement
it and thus effectively leak it. Make sure we decrement it if we
incremented it.
Link: http://lkml.kernel.org/r/b6fe6b879f17fa68eee6cbd876f459f6e5e33495.1526491581.git.osandov@fb.com
Fixes: 81a0298bdfab ("mm, swap: don't use VMA based swap readahead if HDD is used as swap")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/swapfile.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index cc2cf04d9018..78a015fcec3b 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3112,6 +3112,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) unsigned long *frontswap_map = NULL; struct page *page = NULL; struct inode *inode = NULL; + bool inced_nr_rotate_swap = false; if (swap_flags & ~SWAP_FLAGS_VALID) return -EINVAL; @@ -3215,8 +3216,10 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) cluster = per_cpu_ptr(p->percpu_cluster, cpu); cluster_set_null(&cluster->index); } - } else + } else { atomic_inc(&nr_rotate_swap); + inced_nr_rotate_swap = true; + } error = swap_cgroup_swapon(p->type, maxpages); if (error) @@ -3307,6 +3310,8 @@ bad_swap: vfree(swap_map); kvfree(cluster_info); kvfree(frontswap_map); + if (inced_nr_rotate_swap) + atomic_dec(&nr_rotate_swap); if (swap_file) { if (inode && S_ISREG(inode->i_mode)) { inode_unlock(inode); |