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

btrfs: tag as unlikely if statements that check for fs in error state

2026-04-07T17:41:42+00:00

Having the filesystem in an error state, meaning we had a transaction abort, is unexpected. Mark every check for the error state with the unlikely annotation to convey that and to allow the compiler to generate better code. On x86_64, using gcc 14.2.0-19 from Debian, resulted in a slightly reduced object size and better code. Before: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 2008598 175912 15592 2200102 219226 fs/btrfs/btrfs.ko After: $ size fs/btrfs/btrfs.ko text data bss dec hex filename 2008450 175912 15592 2199954 219192 fs/btrfs/btrfs.ko Reviewed-by: Anand Jain Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: pass level to _btrfs_printk() to avoid parsing level from string

2026-02-03T06:49:10+00:00

There's code in _btrfs_printk() to parse the message level from the input string so we can augment the message with the level description for better visibility in the logs. The parsing code has evolved over time, see commits: - 40f7828b36e3b9 ("btrfs: better handle btrfs_printk() defaults") - 262c5e86fec7cf ("printk/btrfs: handle more message headers") - 533574c6bc30cf ("btrfs: use printk_get_level and printk_skip_level, add __printf, fix fallout") - 4da35113426d16 ("btrfs: add varargs to btrfs_error") As we are using the specific level helpers everywhere we can simply pass the message level so we don't have to parse it. The proper printk() message header is created as KERN_SOH + "level". Signed-off-by: David Sterba

btrfs: introduce a new shutdown state

2025-11-24T20:45:03+00:00

A new fs state EMERGENCY_SHUTDOWN is introduced, which is btrfs' equivalent of XFS_IOC_GOINGDOWN or EXT4_IOC_SHUTDOWN, after entering emergency shutdown state, all operations will return errors (-EIO), and can not be bring back to normal state until unmouont. The new state will reject the following file operations: - read_iter() - write_iter() - mmap() - open() - remap_file_range() - uring_cmd() - splice_read() This requires a small wrapper to do the extra shutdown check, then call the regular filemap_splice_read() function This should reject most of the file operations on a shutdown btrfs. And for the existing dirty folios, extra shutdown checks are introduced to the following functions: - run_delalloc_nocow() - run_delalloc_compressed() - cow_file_range() So that dirty ranges will still be properly cleaned without being submitted. Finally the shutdown state will also set the fs error, so that no new transaction will be committed, protecting the metadata from any possible further corruption. And when the fs entered shutdown mode for the first time, a critical level kernel message will show up to indicate the incident. That message will be important for end users as rejected delalloc ranges will output error messages, hopefully that shutdown message and the fact that all fs operations are returning error will prevent end users from getting too confused about the delalloc error messages. Reviewed-by: Johannes Thumshirn Reviewed-by: Anand Jain Tested-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: dump detailed info and specific messages on log replay failures

2025-09-23T06:49:21+00:00

Currently debugging log replay failures can be harder than needed, since all we do now is abort a transaction, which gives us a line number, a stack trace and an error code. But that is most of the times not enough to give some clue about what went wrong. So add a new helper to abort log replay and provide contextual information: 1) Dump the current leaf of the log tree being processed and print the slot we are currently at and the key at that slot; 2) Dump the current subvolume tree leaf if we have any; 3) Print the current stage of log replay; 4) Print the id of the subvolume root associated with the log tree we are currently processing (as we can have multiple); 5) Print some error message to mention what we were trying to do when we got an error. Replace all transaction abort calls (btrfs_abort_transaction()) with the new helper btrfs_abort_log_replay(), which besides dumping all that extra information, it also aborts the current transaction. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: disable rate limiting when debug enabled

2024-10-01T17:29:41+00:00

Disable ratelimiting for btrfs_printk when CONFIG_BTRFS_DEBUG is enabled. This allows for more verbose output which is often needed by functions like btrfs_dump_space_info(). Reviewed-by: Qu Wenruo Signed-off-by: Leo Martins Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: introduce new "rescue=ignoremetacsums" mount option

2024-07-11T13:33:29+00:00

Introduce "rescue=ignoremetacsums" to ignore metadata csums, all the other metadata sanity checks are still kept as is. This new mount option is mostly to allow the kernel to mount an interrupted checksum conversion (at the metadata csum overwrite stage). And since the main part of metadata sanity checks is inside tree-checker, we shouldn't lose much safety, and the new mount option is rescue mount option it requires full read-only mount. Reviewed-by: Josef Bacik Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: remove colon from messages with state

2024-04-17T23:46:35+00:00

The message format in syslog is usually made of two parts: prefix ":" message Various tools parse the prefix up to the first ":". When there's an additional status of a btrfs filesystem like [5.199782] BTRFS info (device nvme1n1p1: state M): use zstd compression, level 9 where 'M' is for remount, there's one more ":" that does not conform to the format. Remove it. Reviewed-by: Anand Jain Signed-off-by: David Sterba

btrfs: remove unused included headers

2024-03-04T15:24:46+00:00

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: constify fs_info parameter in __btrfs_panic()

2023-12-15T19:27:02+00:00

The printk helpers take const fs_info if it's used just for the identifier in the messages, __btrfs_panic() lacks that. Reviewed-by: Josef Bacik Signed-off-by: David Sterba

btrfs: rename errno identifiers to error

2023-10-12T14:44:07+00:00

We sync the kernel files to userspace and the 'errno' symbol is defined by standard library, which does not matter in kernel but the parameters or local variables could clash. Rename them all. Reviewed-by: Qu Wenruo Signed-off-by: David Sterba