kernel/git/stable/linux-stable.git/fs/btrfs/relocation.c, branch linux-6.4.y

btrfs: exit gracefully if reloc roots don't match

2023-08-16T16:32:30+00:00

commit 05d7ce504545f7874529701664c90814ca645c5d upstream. [BUG] Syzbot reported a crash that an ASSERT() got triggered inside prepare_to_merge(). [CAUSE] The root cause of the triggered ASSERT() is we can have a race between quota tree creation and relocation. This leads us to create a duplicated quota tree in the btrfs_read_fs_root() path, and since it's treated as fs tree, it would have ROOT_SHAREABLE flag, causing us to create a reloc tree for it. The bug itself is fixed by a dedicated patch for it, but this already taught us the ASSERT() is not something straightforward for developers. [ENHANCEMENT] Instead of using an ASSERT(), let's handle it gracefully and output extra info about the mismatch reloc roots to help debug. Also with the above ASSERT() removed, we can trigger ASSERT(0)s inside merge_reloc_roots() later. Also replace those ASSERT(0)s with WARN_ON()s. CC: stable@vger.kernel.org # 5.15+ Reported-by: syzbot+ae97a827ae1c3336bbb4@syzkaller.appspotmail.com Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: fix backref walking not returning all inode refs

2023-05-09T20:09:11+00:00

When using the logical to ino ioctl v2, if the flag to ignore offsets of file extent items (BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET) is given, the backref walking code ends up not returning references for all file offsets of an inode that point to the given logical bytenr. This happens since kernel 6.2, commit 6ce6ba534418 ("btrfs: use a single argument for extent offset in backref walking functions") because: 1) It mistakenly skipped the search for file extent items in a leaf that point to the target extent if that flag is given. Instead it should only skip the filtering done by check_extent_in_eb() - that is, it should not avoid the calls to that function (or find_extent_in_eb(), which uses it). 2) It was also not building a list of inode extent elements (struct extent_inode_elem) if we have multiple inode references for an extent when the ignore offset flag is given to the logical to ino ioctl - it would leave a single element, only the last one that was found. These stem from the confusing old interface for backref walking functions where we had an extent item offset argument that was a pointer to a u64 and another boolean argument that indicated if the offset should be ignored, but the pointer could be NULL. That NULL case is used by relocation, qgroup extent accounting and fiemap, simply to avoid building the inode extent list for each reference, as it's not necessary for those use cases and therefore avoids memory allocations and some computations. Fix this by adding a boolean argument to the backref walk context structure to indicate that the inode extent list should not be built, make relocation set that argument to true and fix the backref walking logic to skip the calls to check_extent_in_eb() and find_extent_in_eb() only if this new argument is true, instead of 'ignore_extent_item_pos' being true. A test case for fstests will be added soon, to provide cover not only for these cases but to the logical to ino ioctl in general as well, as currently we do not have a test case for it. Reported-by: Vladimir Panteleev Link: https://lore.kernel.org/linux-btrfs/CAHhfkvwo=nmzrJSqZ2qMfF-rZB-ab6ahHnCD_sq9h4o8v+M7QQ@mail.gmail.com/ Fixes: 6ce6ba534418 ("btrfs: use a single argument for extent offset in backref walking functions") CC: stable@vger.kernel.org # 6.2+ Tested-by: Vladimir Panteleev Signed-off-by: Filipe Manana Signed-off-by: David Sterba

btrfs: open code btrfs_bin_search()

2023-04-17T16:01:15+00:00

btrfs_bin_search() is a simple wrapper that searches for the whole slots by calling btrfs_generic_bin_search() with the starting slot/first_slot preset to 0. This simple wrapper can be open coded as btrfs_bin_search(). Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro

2023-02-13T16:50:34+00:00

The header file linux/mm.h provides PAGE_ALIGN, PAGE_ALIGNED, PAGE_ALIGN_DOWN macros. Use these macros to make code more concise. Signed-off-by: Yushan Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: split the bio submission path into a separate file

2022-12-05T17:00:57+00:00

The code used by btrfs_submit_bio only interacts with the rest of volumes.c through __btrfs_map_block (which itself is a more generic version of two exported helpers) and does not really have anything to do with volumes.c. Create a new bio.c file and a bio.h header going along with it for the btrfs_bio-based storage layer, which will grow even more going forward. Also update the file with my copyright notice given that a large part of the moved code was written or rewritten by me. Reviewed-by: Josef Bacik Reviewed-by: Johannes Thumshirn Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: introduce a bitmap based csum range search function

2022-12-05T17:00:57+00:00

Although we have an existing function, btrfs_lookup_csums_range(), to find all data checksums for a range, it's based on a btrfs_ordered_sum list. For the incoming RAID56 data checksum verification at RMW time, we don't want to waste time by allocating temporary memory. So this patch will introduce a new helper, btrfs_lookup_csums_bitmap(). It will use bitmap based result, which will be a perfect fit for later RAID56 usage. Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: concentrate all tree block parentness check parameters into one structure

2022-12-05T17:00:56+00:00

There are several different tree block parentness check parameters used across several helpers: - level Mandatory - transid Under most cases it's mandatory, but there are several backref cases which skips this check. - owner_root - first_key Utilized by most top-down tree search routine. Otherwise can be skipped. Those four members are not always mandatory checks, and some of them are the same u64, which means if some arguments got swapped compiler will not catch it. Furthermore if we're going to further expand the parentness check, we need to modify quite some helpers just to add one more parameter. This patch will concentrate all these members into a structure called btrfs_tree_parent_check, and pass that structure for the following helpers: - btrfs_read_extent_buffer() - read_tree_block() Signed-off-by: Qu Wenruo Signed-off-by: David Sterba

btrfs: pass btrfs_inode to btrfs_add_delayed_iput

2022-12-05T17:00:55+00:00

The function is for internal interfaces so we should use the btrfs_inode. Reviewed-by: Anand Jain Signed-off-by: David Sterba

btrfs: drop private_data parameter from extent_io_tree_init

2022-12-05T17:00:54+00:00

All callers except one pass NULL, so the parameter can be dropped and the inode::io_tree initialization can be open coded. Reviewed-by: Anand Jain Signed-off-by: David Sterba

btrfs: pass btrfs_inode to btrfs_inode_unlock

2022-12-05T17:00:53+00:00

The function is for internal interfaces so we should use the btrfs_inode. Reviewed-by: Anand Jain Signed-off-by: David Sterba