809981870b
[ Upstream commit ebb70442cdd4872260c2415929c456be3562da82 ] Xfstests btrfs/146 revealed this corruption, [ 58.138831] Buffer I/O error on dev dm-0, logical block 2621424, async page read [ 58.151233] BTRFS error (device sdf): bdev /dev/mapper/error-test errs: wr 1, rd 0, flush 0, corrupt 0, gen 0 [ 58.152403] list_add corruption. prev->next should be next (ffff88005e6775d8), but was ffffc9000189be88. (prev=ffffc9000189be88). [ 58.153518] ------------[ cut here ]------------ [ 58.153892] WARNING: CPU: 1 PID: 1287 at lib/list_debug.c:31 __list_add_valid+0x169/0x1f0 ... [ 58.157379] RIP: 0010:__list_add_valid+0x169/0x1f0 ... [ 58.161956] Call Trace: [ 58.162264] btrfs_log_inode_parent+0x5bd/0xfb0 [btrfs] [ 58.163583] btrfs_log_dentry_safe+0x60/0x80 [btrfs] [ 58.164003] btrfs_sync_file+0x4c2/0x6f0 [btrfs] [ 58.164393] vfs_fsync_range+0x5f/0xd0 [ 58.164898] do_fsync+0x5a/0x90 [ 58.165170] SyS_fsync+0x10/0x20 [ 58.165395] entry_SYSCALL_64_fastpath+0x1f/0xbe ... It turns out that we could record btrfs_log_ctx:io_err in log_one_extents when IO fails, but make log_one_extents() return '0' instead of -EIO, so the IO error is not acknowledged by the callers, i.e. btrfs_log_inode_parent(), which would remove btrfs_log_ctx:list from list head 'root->log_ctxs'. Since btrfs_log_ctx is allocated from stack memory, it'd get freed with a object alive on the list. then a future list_add will throw the above warning. This returns the correct error in the above case. Jeff also reported this while testing against his fsync error patch set[1]. [1]: https://www.spinics.net/lists/linux-btrfs/msg65308.html "btrfs list corruption and soft lockups while testing writeback error handling" Fixes: 8407f553268a4611f254 ("Btrfs: fix data corruption after fast fsync and writeback error") Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.