[cc Amir, the 5.10 stable XFS maintainer] On Tue, Aug 09, 2022 at 11:46:23AM +0000, bugzilla-daemon@xxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=216343 > > Bug ID: 216343 > Summary: XFS: no space left in xlog cause system hang > Product: File System > Version: 2.5 > Kernel Version: 5.10.38 > Hardware: ARM > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: XFS > Assignee: filesystem_xfs@xxxxxxxxxxxxxxxxxxxxxx > Reporter: zhoukete@xxxxxxx > Regression: No > > Created attachment 301539 > --> https://bugzilla.kernel.org/attachment.cgi?id=301539&action=edit > stack > > 1. cannot login with ssh, system hanged and cannot do anything > 2. dmesg report 'audit: audit_backlog=41349 > audit_backlog_limit=8192' > 3. I send sysrq-crash and get vmcore file , I dont know how to reproduce it. > > Follwing is my analysis from vmcore: > > The reason why tty cannot login is pid 2021571 hold the acct_process mutex, and > 2021571 cannot release mutex because it is wait for xlog release space. See the > stac info in the attachment of stack.txt > > So I try to figure out what happened to xlog > > crash> struct xfs_ail.ail_target_prev,ail_targe,ail_head 0xffff00ff884f1000 > ail_target_prev = 0xe9200058600 > ail_target = 0xe9200058600 > ail_head = { > next = 0xffff0340999a0a80, > prev = 0xffff020013c66b40 > } > > there are 112 log item in ail list > crash> list 0xffff0340999a0a80 | wc -l > 112 > > 79 item of them are xlog_inode_item > 30 item of them are xlog_buf_item > > crash> xfs_log_item.li_flags,li_lsn 0xffff0340999a0a80 -x > li_flags = 0x1 > li_lsn = 0xe910005cc00 ===> first item lsn > > crash> xfs_log_item.li_flags,li_lsn ffff020013c66b40 -x > li_flags = 0x1 > li_lsn = 0xe9200058600 ===> last item lsn > > crash>xfs_log_item.li_buf 0xffff0340999a0a80 > li_buf = 0xffff0200125b7180 > > crash> xfs_buf.b_flags 0xffff0200125b7180 -x > b_flags = 0x110032 (XBF_WRITE|XBF_ASYNC|XBF_DONE|_XBF_INODES|_XBF_PAGES) > > crash> xfs_buf.b_state 0xffff0200125b7180 -x > b_state = 0x2 (XFS_BSTATE_IN_FLIGHT) > > crash> xfs_buf.b_last_error,b_retries,b_first_retry_time 0xffff0200125b7180 -x > b_last_error = 0x0 > b_retries = 0x0 > b_first_retry_time = 0x0 > > The buf flags show the io had been done(XBF_DONE is set). > When I review the code xfs_buf_ioend, if XBF_DONE is set, xfs_buf_inode_iodone > will be called and it will remove the log item from ail list, then release the > xlog space by moving the tail_lsn. > > But now this item is still in the ail list, and the b_last_error = 0, XBF_WRITE > is set. > > xfs buf log item is the same as the inode log item. > > crash> list -s xfs_log_item.li_buf 0xffff0340999a0a80 > ffff033f8d7c9de8 > li_buf = 0x0 > crash> xfs_buf_log_item.bli_buf ffff033f8d7c9de8 > bli_buf = 0xffff0200125b4a80 > crash> xfs_buf.b_flags 0xffff0200125b4a80 -x > b_flags = 0x100032 (XBF_WRITE|XBF_ASYNC|XBF_DONE|_XBF_PAGES) > > I think it is impossible that (XBF_DONE is set & b_last_error = 0) and the item > still in the ail. > > Is my analysis correct? > Why xlog space cannot release space? > > -- > You may reply to this email to add a comment. > > You are receiving this mail because: > You are watching the assignee of the bug. -- Dave Chinner david@xxxxxxxxxxxxx
