Date: Sun, 23 Jul 2023 15:43:48 +0000 From: bugzilla-noreply@freebsd.org To: fs@FreeBSD.org Subject: [Bug 272678] VFS: Incorrect data in read from concurrent write Message-ID: <bug-272678-3630-tqvfOb5zAb@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-272678-3630@https.bugs.freebsd.org/bugzilla/> References: <bug-272678-3630@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D272678 Mateusz Guzik <mjg@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mjg@FreeBSD.org --- Comment #4 from Mateusz Guzik <mjg@FreeBSD.org> --- Thanks for the report. Analysis looks mostly right. Until the issue is resolved, it can be worked around with: sysctl debug.vn_io_pgcache_read_enable=3D0 (which you can add to sysctl.con= f) To the bug, while it is correct that the size is updated first and causing trouble, another issue is that pages are only sbusied (as opposed to xbusie= d), thus even if file size remains unchanged, the read may get a transient state which violates the idea of reads and writes maintaining atomicity. truncate should also xbusy, which will sort it out. --=20 You are receiving this mail because: You are the assignee for the bug.=
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