| Message ID | 20171221224256.18196-5-bo.li.liu@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 22.12.2017 00:42, Liu Bo wrote: > This test case simulates the racy situation of buffered write vs dio > read, and see if btrfs_get_extent() would return -EEXIST. Isn't mixing dio/buffered IO on the same file (range?) considered dangerous in any case? > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > --- > fs/btrfs/tests/extent-map-tests.c | 73 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) > > diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c > index 0407396..2adf55f 100644 > --- a/fs/btrfs/tests/extent-map-tests.c > +++ b/fs/btrfs/tests/extent-map-tests.c > @@ -181,6 +181,78 @@ static void test_case_2(struct extent_map_tree *em_tree) > free_extent_map_tree(em_tree); > } > > +static void __test_case_3(struct extent_map_tree *em_tree, u64 start) > +{ > + struct extent_map *em; > + u64 len = SZ_4K; > + int ret; > + > + em = alloc_extent_map(); > + if (!em) > + /* Skip this test on error. */ > + return; > + > + /* Add [4K, 8K) */ > + em->start = SZ_4K; > + em->len = SZ_4K; > + em->block_start = SZ_4K; > + em->block_len = SZ_4K; > + ret = add_extent_mapping(em_tree, em, 0); > + ASSERT(ret == 0); > + free_extent_map(em); > + > + em = alloc_extent_map(); > + if (!em) > + goto out; > + > + /* Add [0, 16K) */ > + em->start = 0; > + em->len = SZ_16K; > + em->block_start = 0; > + em->block_len = SZ_16K; > + ret = btrfs_add_extent_mapping(em_tree, &em, start, len); > + if (ret) > + test_msg("case3 [0x%llx 0x%llx): ret %d\n", > + start, start + len, ret); > + /* > + * Since bytes within em are contiguous, em->block_start is identical to > + * em->start. > + */ > + if (em && > + (start < em->start || start + len > extent_map_end(em) || > + em->start != em->block_start || em->len != em->block_len)) > + test_msg("case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n", > + start, start + len, ret, em->start, em->len, > + em->block_start, em->block_len); > + free_extent_map(em); > +out: > + /* free memory */ > + free_extent_map_tree(em_tree); > +} > + > +/* > + * Test scenario: > + * > + * Suppose that no extent map has been loaded into memory yet. > + * There is a file extent [0, 16K), two jobs are running concurrently > + * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio > + * read from [0, 4K) or [8K, 12K) or [12K, 16K). > + * > + * t1 goes ahead of t2 and adds em [4K, 8K) into tree. > + * > + * t1 t2 > + * cow_file_range() btrfs_get_extent() > + * -> lookup_extent_mapping() > + * -> add_extent_mapping() > + * -> add_extent_mapping() > + */ > +static void test_case_3(struct extent_map_tree *em_tree) > +{ > + __test_case_3(em_tree, 0); > + __test_case_3(em_tree, SZ_8K); > + __test_case_3(em_tree, (12 * 1024ULL)); > +} > + > int btrfs_test_extent_map() > { > struct extent_map_tree *em_tree; > @@ -196,6 +268,7 @@ int btrfs_test_extent_map() > > test_case_1(em_tree); > test_case_2(em_tree); > + test_case_3(em_tree); > > kfree(em_tree); > return 0; > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Dec 22, 2017 at 09:51:24AM +0200, Nikolay Borisov wrote: > > > On 22.12.2017 00:42, Liu Bo wrote: > > This test case simulates the racy situation of buffered write vs dio > > read, and see if btrfs_get_extent() would return -EEXIST. > > Isn't mixing dio/buffered IO on the same file (range?) considered > dangerous in any case? They are, but it is sometimes the way how applications work. thanks, -liubo > > > > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > > --- > > fs/btrfs/tests/extent-map-tests.c | 73 +++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 73 insertions(+) > > > > diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c > > index 0407396..2adf55f 100644 > > --- a/fs/btrfs/tests/extent-map-tests.c > > +++ b/fs/btrfs/tests/extent-map-tests.c > > @@ -181,6 +181,78 @@ static void test_case_2(struct extent_map_tree *em_tree) > > free_extent_map_tree(em_tree); > > } > > > > +static void __test_case_3(struct extent_map_tree *em_tree, u64 start) > > +{ > > + struct extent_map *em; > > + u64 len = SZ_4K; > > + int ret; > > + > > + em = alloc_extent_map(); > > + if (!em) > > + /* Skip this test on error. */ > > + return; > > + > > + /* Add [4K, 8K) */ > > + em->start = SZ_4K; > > + em->len = SZ_4K; > > + em->block_start = SZ_4K; > > + em->block_len = SZ_4K; > > + ret = add_extent_mapping(em_tree, em, 0); > > + ASSERT(ret == 0); > > + free_extent_map(em); > > + > > + em = alloc_extent_map(); > > + if (!em) > > + goto out; > > + > > + /* Add [0, 16K) */ > > + em->start = 0; > > + em->len = SZ_16K; > > + em->block_start = 0; > > + em->block_len = SZ_16K; > > + ret = btrfs_add_extent_mapping(em_tree, &em, start, len); > > + if (ret) > > + test_msg("case3 [0x%llx 0x%llx): ret %d\n", > > + start, start + len, ret); > > + /* > > + * Since bytes within em are contiguous, em->block_start is identical to > > + * em->start. > > + */ > > + if (em && > > + (start < em->start || start + len > extent_map_end(em) || > > + em->start != em->block_start || em->len != em->block_len)) > > + test_msg("case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n", > > + start, start + len, ret, em->start, em->len, > > + em->block_start, em->block_len); > > + free_extent_map(em); > > +out: > > + /* free memory */ > > + free_extent_map_tree(em_tree); > > +} > > + > > +/* > > + * Test scenario: > > + * > > + * Suppose that no extent map has been loaded into memory yet. > > + * There is a file extent [0, 16K), two jobs are running concurrently > > + * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio > > + * read from [0, 4K) or [8K, 12K) or [12K, 16K). > > + * > > + * t1 goes ahead of t2 and adds em [4K, 8K) into tree. > > + * > > + * t1 t2 > > + * cow_file_range() btrfs_get_extent() > > + * -> lookup_extent_mapping() > > + * -> add_extent_mapping() > > + * -> add_extent_mapping() > > + */ > > +static void test_case_3(struct extent_map_tree *em_tree) > > +{ > > + __test_case_3(em_tree, 0); > > + __test_case_3(em_tree, SZ_8K); > > + __test_case_3(em_tree, (12 * 1024ULL)); > > +} > > + > > int btrfs_test_extent_map() > > { > > struct extent_map_tree *em_tree; > > @@ -196,6 +268,7 @@ int btrfs_test_extent_map() > > > > test_case_1(em_tree); > > test_case_2(em_tree); > > + test_case_3(em_tree); > > > > kfree(em_tree); > > return 0; > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c index 0407396..2adf55f 100644 --- a/fs/btrfs/tests/extent-map-tests.c +++ b/fs/btrfs/tests/extent-map-tests.c @@ -181,6 +181,78 @@ static void test_case_2(struct extent_map_tree *em_tree) free_extent_map_tree(em_tree); } +static void __test_case_3(struct extent_map_tree *em_tree, u64 start) +{ + struct extent_map *em; + u64 len = SZ_4K; + int ret; + + em = alloc_extent_map(); + if (!em) + /* Skip this test on error. */ + return; + + /* Add [4K, 8K) */ + em->start = SZ_4K; + em->len = SZ_4K; + em->block_start = SZ_4K; + em->block_len = SZ_4K; + ret = add_extent_mapping(em_tree, em, 0); + ASSERT(ret == 0); + free_extent_map(em); + + em = alloc_extent_map(); + if (!em) + goto out; + + /* Add [0, 16K) */ + em->start = 0; + em->len = SZ_16K; + em->block_start = 0; + em->block_len = SZ_16K; + ret = btrfs_add_extent_mapping(em_tree, &em, start, len); + if (ret) + test_msg("case3 [0x%llx 0x%llx): ret %d\n", + start, start + len, ret); + /* + * Since bytes within em are contiguous, em->block_start is identical to + * em->start. + */ + if (em && + (start < em->start || start + len > extent_map_end(em) || + em->start != em->block_start || em->len != em->block_len)) + test_msg("case3 [0x%llx 0x%llx): ret %d em (start 0x%llx len 0x%llx block_start 0x%llx block_len 0x%llx)\n", + start, start + len, ret, em->start, em->len, + em->block_start, em->block_len); + free_extent_map(em); +out: + /* free memory */ + free_extent_map_tree(em_tree); +} + +/* + * Test scenario: + * + * Suppose that no extent map has been loaded into memory yet. + * There is a file extent [0, 16K), two jobs are running concurrently + * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio + * read from [0, 4K) or [8K, 12K) or [12K, 16K). + * + * t1 goes ahead of t2 and adds em [4K, 8K) into tree. + * + * t1 t2 + * cow_file_range() btrfs_get_extent() + * -> lookup_extent_mapping() + * -> add_extent_mapping() + * -> add_extent_mapping() + */ +static void test_case_3(struct extent_map_tree *em_tree) +{ + __test_case_3(em_tree, 0); + __test_case_3(em_tree, SZ_8K); + __test_case_3(em_tree, (12 * 1024ULL)); +} + int btrfs_test_extent_map() { struct extent_map_tree *em_tree; @@ -196,6 +268,7 @@ int btrfs_test_extent_map() test_case_1(em_tree); test_case_2(em_tree); + test_case_3(em_tree); kfree(em_tree); return 0;
This test case simulates the racy situation of buffered write vs dio read, and see if btrfs_get_extent() would return -EEXIST. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- fs/btrfs/tests/extent-map-tests.c | 73 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+)