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md: free unused memory after bitmap resize 

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>
hifive-unleashed-5.1
Zdenek Kabelac 2017-11-08 13:44:56 +01:00 committed by Shaohua Li
parent 0202ce8a90
commit 0868b99c21
1 changed files with 9 additions and 0 deletions
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9
drivers/md/md-bitmap.c
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@ -2162,6 +2162,7 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
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;
@ -2212,6 +2213,14 @@ int bitmap_resize(struct bitmap *bitmap, sector_t blocks,
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)) {