kernel/git/stable/linux.git/fs/btrfs/send.c, branch master

btrfs: send: fix lost error return value in will_overwrite_ref()

2026-09-02T20:19:30+00:00

The direct-return refactoring in commit b3047a42f55d ("btrfs: send: directly return from will_overwrite_ref() and simplify it") changed will_overwrite_ref() to return directly instead of going through the common out label. That resulted in a negative return value from is_inode_existent() to start being converted to 0, making lookup errors unable to be distinguished from the inode not existing. process_recorded_refs() expects negative errors from will_overwrite_ref() and aborts processing when it receives one. Return the value from is_inode_existent() to restore the previous error propagation behavior as it was before the refactor. Fixes: b3047a42f55d ("btrfs: send: directly return from will_overwrite_ref() and simplify it") Signed-off-by: Avi Weiss Reviewed-by: Filipe Manana Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: send: reject extents for non-regular inodes

2026-09-02T20:19:29+00:00

[BUG] A corrupted subvolume tree can leave an EXTENT_DATA item attached to an inode whose mode is not S_IFREG or S_IFLNK. During send, such an item can be treated as file data and crash through a NULL address_space operation: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page Call Trace: read_pages+0x80b/0xb30 mm/readahead.c:173 page_cache_ra_unbounded+0x40d/0x890 mm/readahead.c:302 do_page_cache_ra mm/readahead.c:332 [inline] page_cache_ra_order+0xa16/0xcd0 mm/readahead.c:535 page_cache_sync_ra+0x5ce/0x9d0 mm/readahead.c:626 page_cache_sync_readahead include/linux/pagemap.h:1379 [inline] put_file_data fs/btrfs/send.c:5224 [inline] send_write fs/btrfs/send.c:5291 [inline] send_extent_data+0x16b2/0x29b0 fs/btrfs/send.c:5715 send_write_or_clone fs/btrfs/send.c:6135 [inline] process_extent+0x5d4/0x17b0 fs/btrfs/send.c:6504 changed_extent fs/btrfs/send.c:7079 [inline] changed_cb+0x22f9/0x3cd0 fs/btrfs/send.c:7245 full_send_tree fs/btrfs/send.c:7318 [inline] send_subvol fs/btrfs/send.c:7910 [inline] btrfs_ioctl_send+0x46a9/0x57f0 fs/btrfs/send.c:8248 ... [CAUSE] process_extent() skips extent items for symlinks but assumes every other inode with an extent item is a regular file. For a corrupted non-regular inode, btrfs_iget() does not install the regular file address_space operations. The readahead fallback can then call a NULL read_folio callback before the existing validation in btrfs_get_extent() can run. [FIX] Reject extent items for inode types other than regular files and symlinks at the common send extent-processing boundary. Symlink handling is left unchanged because send emits symlink data from read_symlink(). This covers full, incremental and new-generation sends without adding a check to the regular I/O path. Reviewed-by: Qu Wenruo Signed-off-by: ZhengYuan Huang Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: add missing sctx check in cleanup path in btrfs_ioctl_send()

2026-08-07T17:17:17+00:00

Add sctx NULL check in the for loop condition of the sort_clone_roots cleanup path for consistency with the else branch. Reviewed-by: Boris Burkov Signed-off-by: Hongling Zeng Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: use correct type for sectorsize/nodesize/blocksize

2026-08-07T17:16:28+00:00

The nodesize and sectorsize are all u32 values, there is no need to use u64 for local usage. Furthermore some call sites also use "blocksize" or "bs" for sectorsize, also change them to use the minimal type u32 instead. Reviewed-by: Boris Burkov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: send: fix is_current_inode_path() to avoid path resets for common prefixes

2026-08-07T17:16:28+00:00

In case the current inode's path is a prefix of the given path, the helper is_current_inode_path() will return true, which causes the single caller to reset the current inode's path. While this is not a functional issue, it makes the caller recompute the current inode's path later. It could also become a problem in the future in case get new callers for is_current_inode_path() in more sensitive contexts. Example: the current inode path is "/foo/bar" and the path we compare against is "/foo/bar_xyz". Fix this by returning true only if we have exact matches. Reviewed-by: Johannes Thumshirn Reviewed-by: Daniel Vacek Signed-off-by: Filipe Manana Signed-off-by: David Sterba

btrfs: send: fix comment for SEND_MAX_DIR_UTIMES_CACHE_SIZE

2026-08-07T17:16:28+00:00

The comment is wrong, because it's not about storing the ID of new directories that were already created, instead it's about storing utimes values for directories (both new and existing). The comment is wrong because it was copy pasted from SEND_MAX_DIR_CREATED_CACHE_SIZE, but forgot to update it afterwards. Reviewed-by: Johannes Thumshirn Reviewed-by: Daniel Vacek Signed-off-by: Filipe Manana Signed-off-by: David Sterba

btrfs: switch local indicator variables to bools

2026-06-09T16:22:46+00:00

For all local indicator variables do simple switch to bool, done on all files. Signed-off-by: David Sterba

btrfs: send: pass bool for pending_move and refs_processed parameters

2026-06-09T16:22:45+00:00

We're passing simple indicators as int, switch them to bool types. Signed-off-by: David Sterba

btrfs: send: switch struct fs_path to auto freeing

2026-06-09T16:22:44+00:00

The fs_path can use the auto freeing pattern and it's completely contained in send. Define the freeing wrapper and add the cleanup attributes. Almost all conversions are straightforward, replacing goto with direct return. Signed-off-by: David Sterba

btrfs: pass literal booleans to functions that take boolean arguments

2026-04-07T16:55:56+00:00

We have several functions with parameters defined as booleans but then we have callers passing integers, 0 or 1, instead of false and true. While this isn't a bug since 0 and 1 are converted to false and true, it is odd and less readable. Change the callers to pass true and false literals instead. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba