506481b20e
When the cow_file_range fails, the related resources are unlocked according to the range [start..end), so the unlock cannot be repeated in run_delalloc_nocow. In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is not updated correctly, so move the cur_offset update before cow_file_range. kernel BUG at mm/page-writeback.c:2663! Internal error: Oops - BUG: 0 [#1] SMP CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O Hardware name: Realtek_RTD1296 (DT) Workqueue: writeback wb_workfn (flush-btrfs-1) task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000 PC is at clear_page_dirty_for_io+0x1bc/0x1e8 LR is at clear_page_dirty_for_io+0x14/0x1e8 pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145 sp : ffffffc02e9af4f0 Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020) Call trace: [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8 [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs] [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs] [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs] [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs] [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs] [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs] [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs] [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs] [<ffffffc00033d758>] do_writepages+0x30/0x88 [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198 [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0 [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0 [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0 [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250 [<ffffffc0002b0014>] process_one_work+0x1dc/0x388 [<ffffffc0002b02f0>] worker_thread+0x130/0x500 [<ffffffc0002b6344>] kthread+0x10c/0x110 [<ffffffc000284590>] ret_from_fork+0x10/0x40 Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000) CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.