blackbird-op-linux/fs/btrfs/ioctl.c, branch master

Merge tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

2020-01-28T23:18:23+00:00

Pull fs deduplication fix from David Sterba: "This is a fix for deduplication bug: the last block of two files is allowed to deduplicated. This got broken in 5.1 by lifting some generic checks to VFS layer. The affected filesystems are btrfs and xfs. The patches are marked for stable as the bug decreases deduplication effectivity" * tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: make deduplication with range including the last block work fs: allow deduplication of eof block into the end of the destination file

Btrfs: make deduplication with range including the last block work

2020-01-23T17:24:07+00:00

Since btrfs was migrated to use the generic VFS helpers for clone and deduplication, it stopped allowing for the last block of a file to be deduplicated when the source file size is not sector size aligned (when eof is somewhere in the middle of the last block). There are two reasons for that: 1) The generic code always rounds down, to a multiple of the block size, the range's length for deduplications. This means we end up never deduplicating the last block when the eof is not block size aligned, even for the safe case where the destination range's end offset matches the destination file's size. That rounding down operation is done at generic_remap_check_len(); 2) Because of that, the btrfs specific code does not expect anymore any non-aligned range length's for deduplication and therefore does not work if such nona-aligned length is given. This patch addresses that second part, and it depends on a patch that fixes generic_remap_check_len(), in the VFS, which was submitted ealier and has the following subject: "fs: allow deduplication of eof block into the end of the destination file" These two patches address reports from users that started seeing lower deduplication rates due to the last block never being deduplicated when the file size is not aligned to the filesystem's block size. Link: https://lore.kernel.org/linux-btrfs/2019-1576167349.500456@svIo.N5dq.dFFD/ CC: stable@vger.kernel.org # 5.1+ Reviewed-by: Josef Bacik Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: drop create parameter to btrfs_get_extent()

2020-01-20T15:40:55+00:00

We only pass this as 1 from __extent_writepage_io(). The parameter basically means "pretend I didn't pass in a page". This is silly since we can simply not pass in the page. Get rid of the parameter from btrfs_get_extent(), and since it's used as a get_extent_t callback, remove it from get_extent_t and btree_get_extent(), neither of which need it. While we're here, let's document btrfs_get_extent(). Signed-off-by: Omar Sandoval Reviewed-by: David Sterba Signed-off-by: David Sterba

Btrfs: always copy scrub arguments back to user space

2020-01-17T14:28:52+00:00

If scrub returns an error we are not copying back the scrub arguments structure to user space. This prevents user space to know how much progress scrub has done if an error happened - this includes -ECANCELED which is returned when users ask for scrub to stop. A particular use case, which is used in btrfs-progs, is to resume scrub after it is canceled, in that case it relies on checking the progress from the scrub arguments structure and then use that progress in a call to resume scrub. So fix this by always copying the scrub arguments structure to user space, overwriting the value returned to user space with -EFAULT only if copying the structure failed to let user space know that either that copying did not happen, and therefore the structure is stale, or it happened partially and the structure is probably not valid and corrupt due to the partial copy. Reported-by: Graham Cobb Link: https://lore.kernel.org/linux-btrfs/d0a97688-78be-08de-ca7d-bcb4c7fb397e@cobb.uk.net/ Fixes: 06fe39ab15a6a4 ("Btrfs: do not overwrite scrub error with fault error in scrub ioctl") CC: stable@vger.kernel.org # 5.1+ Reviewed-by: Johannes Thumshirn Reviewed-by: Qu Wenruo Tested-by: Graham Cobb Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: abort transaction after failed inode updates in create_subvol

2019-12-13T13:10:44+00:00

We can just abort the transaction here, and in fact do that for every other failure in this function except these two cases. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

Btrfs: fix hole extent items with a zero size after range cloning

2019-12-13T13:10:28+00:00

Normally when cloning a file range if we find an implicit hole at the end of the range we assume it is because the NO_HOLES feature is enabled. However that is not always the case. One well known case [1] is when we have a power failure after mixing buffered and direct IO writes against the same file. In such cases we need to punch a hole in the destination file, and if the NO_HOLES feature is not enabled, we need to insert explicit file extent items to represent the hole. After commit 690a5dbfc51315 ("Btrfs: fix ENOSPC errors, leading to transaction aborts, when cloning extents"), we started to insert file extent items representing the hole with an item size of 0, which is invalid and should be 53 bytes (the size of a btrfs_file_extent_item structure), resulting in all sorts of corruptions and invalid memory accesses. This is detected by the tree checker when we attempt to write a leaf to disk. The problem can be sporadically triggered by test case generic/561 from fstests. That test case does not exercise power failure and creates a new filesystem when it starts, so it does not use a filesystem created by any previous test that tests power failure. However the test does both buffered and direct IO writes (through fsstress) and it's precisely that which is creating the implicit holes in files. That happens even before the commit mentioned earlier. I need to investigate why we get those implicit holes to check if there is a real problem or not. For now this change fixes the regression of introducing file extent items with an item size of 0 bytes. Fix the issue by calling btrfs_punch_hole_range() without passing a btrfs_clone_extent_info structure, which ensures file extent items are inserted to represent the hole with a correct item size. We were passing a btrfs_clone_extent_info with a value of 0 for its 'item_size' field, which was causing the insertion of file extent items with an item size of 0. [1] https://www.spinics.net/lists/linux-btrfs/msg75350.html Reported-by: David Sterba Fixes: 690a5dbfc51315 ("Btrfs: fix ENOSPC errors, leading to transaction aborts, when cloning extents") Signed-off-by: Filipe Manana Reviewed-by: Josef Bacik Signed-off-by: David Sterba

btrfs: rename btrfs_block_group_cache

2019-11-18T16:51:51+00:00

The type name is misleading, a single entry is named 'cache' while this normally means a collection of objects. Rename that everywhere. Also the identifier was quite long, making function prototypes harder to format. Suggested-by: Nikolay Borisov Reviewed-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: add dedicated members for start and length of a block group

2019-11-18T16:51:45+00:00

The on-disk format of block group item makes use of the key that stores the offset and length. This is further used in the code, although this makes thing harder to understand. The key is also packed so the offset/length is not properly aligned as u64. Add start (key.objectid) and length (key.offset) members to block group and remove the embedded key. When the item is searched or written, a local variable for key is used. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Reviewed-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: move block_group_item::used to block group

2019-11-18T16:51:44+00:00

For unknown reasons, the member 'used' in the block group struct is stored in the b-tree item and accessed everywhere using the special accessor helper. Let's unify it and make it a regular member and only update the item before writing it to the tree. The item is still being used for flags and chunk_objectid, there's some duplication until the item is removed in following patches. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Reviewed-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: ioctl: Try to use btrfs_fs_info instead of *file

2019-11-18T11:46:55+00:00

Some functions are doing some unnecessary indirection to reach the btrfs_fs_info struct. Change these functions to receive a btrfs_fs_info struct instead of a *file. Reviewed-by: Anand Jain Reviewed-by: Nikolay Borisov Signed-off-by: Marcos Paulo de Souza Reviewed-by: David Sterba Signed-off-by: David Sterba