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author | Al Viro <viro@zeniv.linux.org.uk> | 2012-04-20 21:49:41 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-04-21 01:58:16 -0400 |
commit | 936af1576e4c24b466380fc2b8d93352161d13b0 (patch) | |
tree | b7ecc2a4706ab25b0d06af7bac5fdf5d0fc7acb5 /fs/aio.c | |
parent | 6be5ceb02e98eaf6cfc4f8b12a896d04023f340d (diff) | |
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aio: don't bother with unmapping when aio_free_ring() is coming from exit_aio()
... since exit_mmap() is coming and it will munmap() everything anyway.
In all other cases aio_free_ring() has ctx->mm == current->mm; moreover,
all other callers of vm_munmap() have mm == current->mm, so this will
allow us to get rid of mm argument of vm_munmap().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/aio.c')
-rw-r--r-- | fs/aio.c | 15 |
1 files changed, 14 insertions, 1 deletions
@@ -92,8 +92,10 @@ static void aio_free_ring(struct kioctx *ctx) for (i=0; i<info->nr_pages; i++) put_page(info->ring_pages[i]); - if (info->mmap_size) + if (info->mmap_size) { + BUG_ON(ctx->mm != current->mm); vm_munmap(ctx->mm, info->mmap_base, info->mmap_size); + } if (info->ring_pages && info->ring_pages != info->internal_pages) kfree(info->ring_pages); @@ -386,6 +388,17 @@ void exit_aio(struct mm_struct *mm) "exit_aio:ioctx still alive: %d %d %d\n", atomic_read(&ctx->users), ctx->dead, ctx->reqs_active); + /* + * We don't need to bother with munmap() here - + * exit_mmap(mm) is coming and it'll unmap everything. + * Since aio_free_ring() uses non-zero ->mmap_size + * as indicator that it needs to unmap the area, + * just set it to 0; aio_free_ring() is the only + * place that uses ->mmap_size, so it's safe. + * That way we get all munmap done to current->mm - + * all other callers have ctx->mm == current->mm. + */ + ctx->ring_info.mmap_size = 0; put_ioctx(ctx); } } |