[LU-18495] osd_ldiskfs_write_record(): adding bh without locking off

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: WC Triage
• Reporter: Alex Zhuravlev

Description

osd_ldiskfs_write_record() tries to optimize writes to an already existing block taking no lock (which normally needed to allocate and initialize non-allocated block).
the optimization is based on the observation that this function is used with non-sparse files mostly, but sometimes this is not true. in this case we still need to grab the semaphore otherwise we risk to use a non-initialized block (before memset(0) is called).