kernel/fs/btrfs/uuid-tree.c, branch linux-rolling-stable

btrfs: fix transaction abort on set received ioctl due to item overflow

2026-03-19T15:15:28Z

commit 87f2c46003fce4d739138aab4af1942b1afdadac upstream. If the set received ioctl fails due to an item overflow when attempting to add the BTRFS_UUID_KEY_RECEIVED_SUBVOL we have to abort the transaction since we did some metadata updates before. This means that if a user calls this ioctl with the same received UUID field for a lot of subvolumes, we will hit the overflow, trigger the transaction abort and turn the filesystem into RO mode. A malicious user could exploit this, and this ioctl does not even requires that a user has admin privileges (CAP_SYS_ADMIN), only that he/she owns the subvolume. Fix this by doing an early check for item overflow before starting a transaction. This is also race safe because we are holding the subvol_sem semaphore in exclusive (write) mode. A test case for fstests will follow soon. Fixes: dd5f9615fc5c ("Btrfs: maintain subvolume items in the UUID tree") CC: stable@vger.kernel.org # 3.12+ Reviewed-by: Anand Jain Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman

btrfs: more trivial BTRFS_PATH_AUTO_FREE conversions

2025-11-24T20:59:11Z

Convert more of the trivial pattern for the auto freeing of btrfs_path with goto -> return conversions where applicable. Signed-off-by: Sun YangKai Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: uuid-tree: remove unnecessary call to btrfs_mark_buffer_dirty()

2025-01-13T13:53:20Z

The call to btrfs_mark_buffer_dirty() at btrfs_uuid_tree_add() is not necessary as we have a path setup for writing with btrfs_search_slot() having a 'cow' argument set to 1 (through btrfs_insert_empty_item()). This just makes the code more verbose, confusing and add a little extra overhead and well as increase the module's text size, so remove it. Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Signed-off-by: David Sterba

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23Z

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

btrfs: move uuid tree related code to uuid-tree.[ch]

2024-09-10T14:51:12Z

Functions btrfs_uuid_scan_kthread() and btrfs_create_uuid_tree() are for UUID tree rescan and creation, it's not suitable for volumes.[ch]. Move them to uuid-tree.[ch] instead. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: constify pointer parameters where applicable

2024-07-11T13:33:22Z

We can add const to many parameters, this is for clarity and minor addition to safety. There are some minor effects, in the assembly code and .ko measured on release config. This patch does not cover all possible conversions. Signed-off-by: David Sterba

btrfs: unify handling of return values of btrfs_insert_empty_items()

2024-03-04T15:24:48Z

The error values returned by btrfs_insert_empty_items() are following the common patter of 0/-errno, but some callers check for a value > 0, which can't happen. Document that and update calls to not expect positive values. Reviewed-by: Josef Bacik Reviewed-by: Anand Jain Signed-off-by: David Sterba

btrfs: remove unused included headers

2024-03-04T15:24:46Z

With help of neovim, LSP and clangd we can identify header files that are not actually needed to be included in the .c files. This is focused only on removal (with minor fixups), further cleanups are possible but will require doing the header files properly with forward declarations, minimized includes and include-what-you-use care. Reviewed-by: Josef Bacik Signed-off-by: David Sterba

btrfs: abort transaction on generation mismatch when marking eb as dirty

2023-10-12T14:44:07Z

When marking an extent buffer as dirty, at btrfs_mark_buffer_dirty(), we check if its generation matches the running transaction and if not we just print a warning. Such mismatch is an indicator that something really went wrong and only printing a warning message (and stack trace) is not enough to prevent a corruption. Allowing a transaction to commit with such an extent buffer will trigger an error if we ever try to read it from disk due to a generation mismatch with its parent generation. So abort the current transaction with -EUCLEAN if we notice a generation mismatch. For this we need to pass a transaction handle to btrfs_mark_buffer_dirty() which is always available except in test code, in which case we can pass NULL since it operates on dummy extent buffers and all test roots have a single node/leaf (root node at level 0). Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: move uuid tree prototypes to uuid-tree.h

2022-12-05T17:00:46Z

Move these out of ctree.h into uuid-tree.h to cut down on the code in ctree.h. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba