4.9-stable review patch. If anyone has any objections, please let me know.
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From: Zdenek Kabelac zkabelac@redhat.com
[ Upstream commit 0868b99c214a3d55486c700de7c3f770b7243e7c ]
When bitmap is resized, the old kalloced chunks just are not released once the resized bitmap starts to use new space.
This fixes in particular kmemleak reports like this one:
unreferenced object 0xffff8f4311e9c000 (size 4096): comm "lvm", pid 19333, jiffies 4295263268 (age 528.265s) hex dump (first 32 bytes): 02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80 ................ 02 80 02 80 02 80 02 80 02 80 02 80 02 80 02 80 ................ backtrace: [<ffffffffa69471ca>] kmemleak_alloc+0x4a/0xa0 [<ffffffffa628c10e>] kmem_cache_alloc_trace+0x14e/0x2e0 [<ffffffffa676cfec>] bitmap_checkpage+0x7c/0x110 [<ffffffffa676d0c5>] bitmap_get_counter+0x45/0xd0 [<ffffffffa676d6b3>] bitmap_set_memory_bits+0x43/0xe0 [<ffffffffa676e41c>] bitmap_init_from_disk+0x23c/0x530 [<ffffffffa676f1ae>] bitmap_load+0xbe/0x160 [<ffffffffc04c47d3>] raid_preresume+0x203/0x2f0 [dm_raid] [<ffffffffa677762f>] dm_table_resume_targets+0x4f/0xe0 [<ffffffffa6774b52>] dm_resume+0x122/0x140 [<ffffffffa6779b9f>] dev_suspend+0x18f/0x290 [<ffffffffa677a3a7>] ctl_ioctl+0x287/0x560 [<ffffffffa677a693>] dm_ctl_ioctl+0x13/0x20 [<ffffffffa62d6b46>] do_vfs_ioctl+0xa6/0x750 [<ffffffffa62d7269>] SyS_ioctl+0x79/0x90 [<ffffffffa6956d41>] entry_SYSCALL_64_fastpath+0x1f/0xc2
Signed-off-by: Zdenek Kabelac zkabelac@redhat.com Signed-off-by: Shaohua Li shli@fb.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/bitmap.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -2084,6 +2084,7 @@ int bitmap_resize(struct bitmap *bitmap, for (k = 0; k < page; k++) { kfree(new_bp[k].map); } + kfree(new_bp);
/* restore some fields from old_counts */ bitmap->counts.bp = old_counts.bp; @@ -2134,6 +2135,14 @@ int bitmap_resize(struct bitmap *bitmap, block += old_blocks; }
+ if (bitmap->counts.bp != old_counts.bp) { + unsigned long k; + for (k = 0; k < old_counts.pages; k++) + if (!old_counts.bp[k].hijacked) + kfree(old_counts.bp[k].map); + kfree(old_counts.bp); + } + if (!init) { int i; while (block < (chunks << chunkshift)) {