kernel.git/fs/btrfs/sysfs.c, branch linux-6.15.y

btrfs: allow debug builds to accept 2K block size

2025-03-18T19:35:49Z

Currently we only support two block sizes, 4K and PAGE_SIZE. This means on the most common architecture x86_64, we have no way to test subpage block size. And that's exactly I have an aarch64 machine dedicated for subpage tests. But this is still a hurdle for a lot of btrfs developers, and to improve the test coverage mostly on x86_64, here we enable debug builds to accept 2K block size. This involves: - Introduce a dedicated minimal block size macro BTRFS_MIN_BLOCKSIZE, which depends on if CONFIG_BTRFS_DEBUG is set. If so it's 2K, otherwise it's 4K as usual. - Allow 4K, PAGE_SIZE and BTRFS_MIN_BLOCKSIZE as block size - Update subpage block size checks to be based on BTRFS_MIN_BLOCKSIZE - Export the new supported blocksize through sysfs interfaces As most of the subpage support is already pretty mature, there is no extra work needed to support the extra 2K block size. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: accept size suffixes for read policy values

2025-03-18T19:35:48Z

We now parse human-friendly size values (e.g. '1G', '2M') when setting read policies. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: replace deprecated strncpy() with strscpy()

2025-02-26T08:24:01Z

strncpy() is deprecated for NUL-terminated destination buffers. Use strscpy() instead and don't zero-initialize the param array. Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Thorsten Blum Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: configure read policy via module parameter

2025-01-13T13:53:21Z

For testing purposes allow to configure the read policy via module parameter from the beginning. Available only with CONFIG_BTRFS_EXPERIMENTAL Examples: - Set the RAID1 balancing method to round-robin with a custom min_contig_read of 4k: $ modprobe btrfs read_policy=round-robin:4096 - Set the round-robin balancing method with the default min_contiguous_read: $ modprobe btrfs read_policy=round-robin - Set the "devid" balancing method, defaulting to the latest device: $ modprobe btrfs read_policy=devid Signed-off-by: Anand Jain Signed-off-by: David Sterba

btrfs: add read policy to set a preferred device

2025-01-13T13:53:21Z

Add read policy that will force all reads to go to the given device (specified by devid) on the RAID1 profiles. This will be used for testing, e.g. to read from stale device. Users may find other use cases. Can be set in sysfs, the value format is "devid:" to the file /sys/fs/btrfs/FSID/read_policy Signed-off-by: Anand Jain Signed-off-by: David Sterba

btrfs: introduce RAID1 round-robin read balancing

2025-01-13T13:53:21Z

Add round-robin read policy that balances reads over available devices (all RAID1 block group profiles). Switch to the next devices is done after a number of blocks is read, which is 256K by default and is configurable in sysfs. The format is "round-robin:" and can be set in file /sys/fs/btrfs/FSID/read_policy Signed-off-by: Anand Jain Signed-off-by: David Sterba

btrfs: sysfs: handle value associated with read balancing policy

2025-01-13T13:53:21Z

Enable specifying additional configuration values along the RAID1 balancing read policy in a single input string. Update btrfs_read_policy_to_enum() to parse and handle a value associated with the policy in the format "policy:value", the value part if present is converted to 64-bit integer. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: add btrfs_read_policy_to_enum() helper and refactor read policy store

2025-01-13T13:53:21Z

Introduce btrfs_read_policy_to_enum() helper to simplify the conversion of a string read policy to its corresponding enum value. This reduces duplication and improves code clarity in btrfs_read_policy_store(). The parameter is copied locally to allow modification, enabling the separation of the method and its value. This prepares for the addition of more functionality in subsequent patches. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: refactor output formatting in btrfs_read_policy_show()

2025-01-13T13:53:20Z

Refactor the logic in btrfs_read_policy_show() for easier extension with more balancing methods. Streamline the space and bracket handling around the active policy without altering the functional output. This is in preparation to add more methods. Signed-off-by: Anand Jain Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: sysfs: fix direct super block member reads

2024-12-23T21:06:44Z

The following sysfs entries are reading super block member directly, which can have a different endian and cause wrong values: - sys/fs/btrfs//nodesize - sys/fs/btrfs//sectorsize - sys/fs/btrfs//clone_alignment Thankfully those values (nodesize and sectorsize) are always aligned inside the btrfs_super_block, so it won't trigger unaligned read errors, just endian problems. Fix them by using the native cached members instead. Fixes: df93589a1737 ("btrfs: export more from FS_INFO to sysfs") CC: stable@vger.kernel.org Reviewed-by: Naohiro Aota Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba