ext4: Avoid entering writeback paths during fastcommit replay

Fastcommit replay effectively happens in nojournal mode. This results in
ext4_mark_iloc_dirty() setting I_METADATA_WRITEBACK flag and as a result
we end up entering filesystem writeback functions. However during
fastcommit replay s_writepages_rwsem isn't initialized yet and hence we
crash.

Fix the problem by avoiding setting I_METADATA_WRITEBACK during
fastcommit replay. Journal replay flushes the whole block device after
replay anyway so all metadata is properly persisted and replay is faster
this way as a bonus.

Fixes: c26339e1df ("ext4: Fix data integrity writeout issues in nojournal mode")
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reported-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260804104112.93202-2-jack@suse.cz
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This commit is contained in:
Jan Kara 2026-08-04 12:41:13 +02:00 • committed by Christian Brauner
commit 0ecd56573c
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