8df507cbb5
[BUG] For the following file layout, scrub will not be able to repair all these two repairable error, but in fact make one corruption even unrepairable: inode offset 0 4k 8K Mirror 1 |XXXXXX| | Mirror 2 | |XXXXXX| [CAUSE] The root cause is the hard coded PAGE_SIZE, which makes scrub repair to go crazy for subpage. For above case, when reading the first sector, we use PAGE_SIZE other than sectorsize to read, which makes us to read the full range [0, 64K). In fact, after 8K there may be no data at all, we can just get some garbage. Then when doing the repair, we also writeback a full page from mirror 2, this means, we will also writeback the corrupted data in mirror 2 back to mirror 1, leaving the range [4K, 8K) unrepairable. [FIX] This patch will modify the following PAGE_SIZE use with sectorsize: - scrub_print_warning_inode() Remove the min() and replace PAGE_SIZE with sectorsize. The min() makes no sense, as csum is done for the full sector with padding. This fixes a bug that subpage report extra length like: checksum error at logical 298844160 on dev /dev/mapper/arm_nvme-test, physical 575668224, root 5, inode 257, offset 0, length 12288, links 1 (path: file) Where the error is only 1 sector. - scrub_handle_errored_block() Comments with PAGE|page involved, all changed to sector. - scrub_setup_recheck_block() - scrub_repair_page_from_good_copy() - scrub_add_page_to_wr_bio() - scrub_wr_submit() - scrub_add_page_to_rd_bio() - scrub_block_complete() Replace PAGE_SIZE with sectorsize. This solves several problems where we read/write extra range for subpage case. RAID56 code is excluded intentionally, as RAID56 has extra PAGE_SIZE usage, and is not really safe enough. Thus we will reject RAID56 for subpage in later commit. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.