linux-dev/fs/btrfs/Makefile, branch master

btrfs: move extent state init and alloc functions to their own file

2022-09-26T10:28:03Z

Start cleaning up extent_io.c by moving the extent state code out of it. This patch starts with the extent state allocation code and the extent_io_tree init code. Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

Kbuild: add -Wno-shift-negative-value where -Wextra is used

2022-03-13T08:30:31Z

As a preparation for moving to -std=gnu11, turn off the -Wshift-negative-value option. This warning is enabled by gcc when building with -Wextra for c99 or higher, but not for c89. Since the kernel already relies on well-defined overflow behavior, the warning is not helpful and can simply be disabled in all locations that use -Wextra. Signed-off-by: Arnd Bergmann Acked-by: Jani Nikula Reviewed-by: Nathan Chancellor Tested-by: Sedat Dilek # LLVM/Clang v13.0.0 (x86-64) Signed-off-by: Masahiro Yamada

btrfs: remove reada infrastructure

2022-01-07T13:18:26Z

Currently there is only one user for btrfs metadata readahead, and that's scrub. But even for the single user, it's not providing the correct functionality it needs, as scrub needs reada for commit root, which current readahead can't provide. (Although it's pretty easy to add such feature). Despite this, there are some extra problems related to metadata readahead: - Duplicated feature with btrfs_path::reada - Partly duplicated feature of btrfs_fs_info::buffer_radix Btrfs already caches its metadata in buffer_radix, while readahead tries to read the tree block no matter if it's already cached. - Poor layer separation Metadata readahead works kinda at device level. This is definitely not the correct layer it should be, since metadata is at btrfs logical address space, it should not bother device at all. This brings extra chance for bugs to sneak in, while brings unnecessary complexity. - Dead code In the very beginning of scrub.c we have #undef DEBUG, rendering all the debug related code useless and unable to test. Thus here I purpose to remove the metadata readahead mechanism completely. [BENCHMARK] There is a full benchmark for the scrub performance difference using the old btrfs_reada_add() and btrfs_path::reada. For the worst case (no dirty metadata, slow HDD), there could be a 5% performance drop for scrub. For other cases (even SATA SSD), there is no distinguishable performance difference. The number is reported scrub speed, in MiB/s. The resolution is limited by the reported duration, which only has a resolution of 1 second. Old New Diff SSD 455.3 466.332 +2.42% HDD 103.927 98.012 -5.69% Comprehensive test methodology is in the cover letter of the patch. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: initial fsverity support

2021-08-23T11:19:09Z

Add support for fsverity in btrfs. To support the generic interface in fs/verity, we add two new item types in the fs tree for inodes with verity enabled. One stores the per-file verity descriptor and btrfs verity item and the other stores the Merkle tree data itself. Verity checking is done in end_page_read just before a page is marked uptodate. This naturally handles a variety of edge cases like holes, preallocated extents, and inline extents. Some care needs to be taken to not try to verity pages past the end of the file, which are accessed by the generic buffered file reading code under some circumstances like reading to the end of the last page and trying to read again. Direct IO on a verity file falls back to buffered reads. Verity relies on PageChecked for the Merkle tree data itself to avoid re-walking up shared paths in the tree. For this reason, we need to cache the Merkle tree data. Since the file is immutable after verity is turned on, we can cache it at an index past EOF. Use the new inode ro_flags to store verity on the inode item, so that we can enable verity on a file, then rollback to an older kernel and still mount the file system and read the file. Since we can't safely write the file anymore without ruining the invariants of the Merkle tree, we mark a ro_compat flag on the file system when a file has verity enabled. Acked-by: Eric Biggers Co-developed-by: Chris Mason Signed-off-by: Chris Mason Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move the tree mod log code into its own file

2021-04-19T15:25:16Z

The tree modification log, which records modifications done to btrees, is quite large and currently spread all over ctree.c, which is a huge file already. To make things better organized, move all that code into its own separate source and header files. Functions and definitions that are used outside of the module (mostly by ctree.c) are renamed so that they start with a "btrfs_" prefix. Everything else remains unchanged. This makes it easier to go over the tree modification log code every time I need to go read it to fix a bug. Reviewed-by: Anand Jain Signed-off-by: Filipe Manana Reviewed-by: David Sterba [ minor comment updates ] Signed-off-by: David Sterba

btrfs: fix build when using M=fs/btrfs

2021-03-17T18:42:18Z

There are people building the module with M= that's supposed to be used for external modules. This got broken in e9aa7c285d20 ("btrfs: enable W=1 checks for btrfs"). $ make M=fs/btrfs scripts/Makefile.lib:10: *** Recursive variable 'KBUILD_CFLAGS' references itself (eventually). Stop. make: *** [Makefile:1755: modules] Error 2 There's a difference compared to 'make fs/btrfs/btrfs.ko' which needs to rebuild a few more things and also the dependency modules need to be available. It could fail with eg. WARNING: Symbol version dump "Module.symvers" is missing. Modules may not have dependencies or modversions. In some environments it's more convenient to rebuild just the btrfs module by M= so let's make it work. The problem is with recursive variable evaluation in += so the conditional C options are stored in a temporary variable to avoid the recursion. Signed-off-by: David Sterba

btrfs: introduce the skeleton of btrfs_subpage structure

2021-02-08T21:59:01Z

For sectorsize < page size support, we need a structure to record extra status info for each sector of a page. Introduce the skeleton structure, all subpage related code would go to subpage.[ch]. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: enable W=1 checks for btrfs

2021-02-08T21:58:55Z

Now that the btrfs' codebase is clean of almost all W=1 warnings let's enable those checks unconditionally for the entire fs/btrfs/ and its subdirectories to catch potential errors during development. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba [ add some comments ] Signed-off-by: David Sterba

btrfs: remove inode number cache feature

2020-12-09T18:16:05Z

It's been deprecated since commit b547a88ea577 ("btrfs: start deprecation of mount option inode_cache") which enumerates the reasons. A filesystem that uses the feature (mount -o inode_cache) tracks the inode numbers in bitmaps, that data stay on the filesystem after this patch. The size is roughly 5MiB for 1M inodes [1], which is considered small enough to be left there. Removal of the change can be implemented in btrfs-progs if needed. [1] https://lore.kernel.org/linux-btrfs/20201127145836.GZ6430@twin.jikos.cz/ Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba

btrfs: get zone information of zoned block devices

2020-12-09T18:15:57Z

If a zoned block device is found, get its zone information (number of zones and zone size). To avoid costly run-time zone report commands to test the device zones type during block allocation, attach the seq_zones bitmap to the device structure to indicate if a zone is sequential or accept random writes. Also it attaches the empty_zones bitmap to indicate if a zone is empty or not. This patch also introduces the helper function btrfs_dev_is_sequential() to test if the zone storing a block is a sequential write required zone and btrfs_dev_is_empty_zone() to test if the zone is a empty zone. Reviewed-by: Josef Bacik Reviewed-by: Anand Jain Signed-off-by: Damien Le Moal Signed-off-by: Naohiro Aota Reviewed-by: David Sterba Signed-off-by: David Sterba