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Patch series "rewrite error handling during mounting stage". This patch (of 5): After commitda5e7c8782("ocfs2: cleanup journal init and shutdown"), journal init later than before, it makes NULL pointer access in free routine. Crash flow: ocfs2_fill_super + ocfs2_mount_volume | + ocfs2_dlm_init //fail & return, osb->journal is NULL. | + ... | + ocfs2_check_volume //no chance to init osb->journal | + ... + ocfs2_dismount_volume ocfs2_release_system_inodes ... evict ... ocfs2_clear_inode ocfs2_checkpoint_inode ocfs2_ci_fully_checkpointed time_after(journal->j_trans_id, ci->ci_last_trans) + journal is empty, crash! For fixing, there are three solutions: 1> Partly revert commitda5e7c8782For avoiding kernel crash, this make sense for us. We only concerned whether there has any non-system inode access before dlm init. The answer is NO. And all journal replay/recovery handling happen after dlm & journal init done. So this method is not graceful but workable. 2> Add osb->journal check in free inode routine (eg ocfs2_clear_inode) The fix code is special for mounting phase, but it will continue working after mounting stage. In another word, this method adds useless code in normal inode free flow. 3> Do directly free inode in mounting phase This method is brutal/complex and may introduce unsafe code, currently maintainer didn't like. At last, we chose method <1> and did partly reverted job. We reverted journal init codes, and kept cleanup codes flow. Link: https://lkml.kernel.org/r/20220424130952.2436-1-heming.zhao@suse.com Link: https://lkml.kernel.org/r/20220424130952.2436-2-heming.zhao@suse.com Fixes:da5e7c8782("ocfs2: cleanup journal init and shutdown") Signed-off-by: Heming Zhao <heming.zhao@suse.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.