Re: Understanding locking for buf
- Reply: Konstantin Belousov : "Re: Understanding locking for buf"
- In reply to: Konstantin Belousov : "Re: Understanding locking for buf"
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Date: Mon, 27 Feb 2023 15:04:30 UTC
On 27.02.23 15:23, Konstantin Belousov wrote: > Not quite. Sync io (bread()) means that caller performs bufwait() on the > buffer. It is still subject to the LK_KERNPROC ownership move. Ehm. Has this behavior changed recently? Our kernel version uses LK_KERNPROC to distinguish between sync and async IO. How would that be possible if ownershipt changes in either case? https://iris.cs.tu-dortmund.de/freebsd-lockdoc/latest/source/sys/geom/geom_vfs.c#L127 > >> Am I right that even in this situation the accesses from g_vfs_done are >> performed? > I hope that the previous note answers this. > >> Can those accesses be considered as valid exceptions of the overall locking >> rule 'use b_lock' since the buf is locked? > I am not sure what would be 'valid exceptions'. I explained the locking scheme > used. - Alex -- Technische Universität Dortmund Computer Science XII - System Software Group Alexander Lochmann PGP key: 0xBC3EF6FD Otto-Hahn-Str. 16 phone: +49.231.7556141 D-44227 Dortmund fax: +49.231.7556116 https://sys.cs.tu-dortmund.de/al