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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-22 19:03:49 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-22 19:03:49 (GMT) |
commit | a8472b4bb1aaa421b10f2cc40f70097e67f971ae (patch) | |
tree | 3f345e0c1c4f9986ba1c8f3cd541f47fbe30b985 /fs | |
parent | 3dc9acb67600393249a795934ccdfc291a200e6b (diff) | |
parent | 8e321fefb0e60bae4e2a28d20fc4fa30758d27c6 (diff) | |
download | linux-a8472b4bb1aaa421b10f2cc40f70097e67f971ae.tar.xz |
Merge git://git.kvack.org/~bcrl/aio-next
Pull AIO leak fixes from Ben LaHaise:
"I've put these two patches plus Linus's change through a round of
tests, and it passes millions of iterations of the aio numa
migratepage test, as well as a number of repetitions of a few simple
read and write tests.
The first patch fixes the memory leak Kent introduced, while the
second patch makes aio_migratepage() much more paranoid and robust"
* git://git.kvack.org/~bcrl/aio-next:
aio/migratepages: make aio migrate pages sane
aio: fix kioctx leak introduced by "aio: Fix a trinity splat"
Diffstat (limited to 'fs')
-rw-r--r-- | fs/aio.c | 55 |
1 files changed, 46 insertions, 9 deletions
@@ -244,9 +244,14 @@ static void aio_free_ring(struct kioctx *ctx) int i; for (i = 0; i < ctx->nr_pages; i++) { + struct page *page; pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i, page_count(ctx->ring_pages[i])); - put_page(ctx->ring_pages[i]); + page = ctx->ring_pages[i]; + if (!page) + continue; + ctx->ring_pages[i] = NULL; + put_page(page); } put_aio_ring_file(ctx); @@ -280,18 +285,38 @@ static int aio_migratepage(struct address_space *mapping, struct page *new, unsigned long flags; int rc; + rc = 0; + + /* Make sure the old page hasn't already been changed */ + spin_lock(&mapping->private_lock); + ctx = mapping->private_data; + if (ctx) { + pgoff_t idx; + spin_lock_irqsave(&ctx->completion_lock, flags); + idx = old->index; + if (idx < (pgoff_t)ctx->nr_pages) { + if (ctx->ring_pages[idx] != old) + rc = -EAGAIN; + } else + rc = -EINVAL; + spin_unlock_irqrestore(&ctx->completion_lock, flags); + } else + rc = -EINVAL; + spin_unlock(&mapping->private_lock); + + if (rc != 0) + return rc; + /* Writeback must be complete */ BUG_ON(PageWriteback(old)); - put_page(old); + get_page(new); - rc = migrate_page_move_mapping(mapping, new, old, NULL, mode); + rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1); if (rc != MIGRATEPAGE_SUCCESS) { - get_page(old); + put_page(new); return rc; } - get_page(new); - /* We can potentially race against kioctx teardown here. Use the * address_space's private data lock to protect the mapping's * private_data. @@ -303,13 +328,24 @@ static int aio_migratepage(struct address_space *mapping, struct page *new, spin_lock_irqsave(&ctx->completion_lock, flags); migrate_page_copy(new, old); idx = old->index; - if (idx < (pgoff_t)ctx->nr_pages) - ctx->ring_pages[idx] = new; + if (idx < (pgoff_t)ctx->nr_pages) { + /* And only do the move if things haven't changed */ + if (ctx->ring_pages[idx] == old) + ctx->ring_pages[idx] = new; + else + rc = -EAGAIN; + } else + rc = -EINVAL; spin_unlock_irqrestore(&ctx->completion_lock, flags); } else rc = -EBUSY; spin_unlock(&mapping->private_lock); + if (rc == MIGRATEPAGE_SUCCESS) + put_page(old); + else + put_page(new); + return rc; } #endif @@ -640,7 +676,8 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) aio_nr += ctx->max_reqs; spin_unlock(&aio_nr_lock); - percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */ + percpu_ref_get(&ctx->users); /* io_setup() will drop this ref */ + percpu_ref_get(&ctx->reqs); /* free_ioctx_users() will drop this */ err = ioctx_add_table(ctx, mm); if (err) |