Date: Mon, 23 Mar 2026 19:14:59 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 294010] NFSv4: cp fails when restoring from a ZFS snapshot (copy_file_range issue) Message-ID: <bug-294010-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=294010 Bug ID: 294010 Summary: NFSv4: cp fails when restoring from a ZFS snapshot (copy_file_range issue) Product: Base System Version: 14.4-RELEASE Hardware: amd64 OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: pmc@citylink.dinoex.sub.org Background: ZFS filesets carry a hidden .zfs directory at their toplevel. Within that directory are the current snapsots of this fileset mounted as readonly trees. Therfore, after one accidentally deletes a file and a suitable snapshot exists, one might just restore the file from that snapshot: $ cp .../.zfs/snapshot/snapshot_X/someplace/somefile .../someplace/somefile Problem: Doing this on a local ZFS fileset works as expected. But doing it via NFS on a remote ZFS fileset copies 0 byte (the empty file is created) and then reports the error "Read-only file system". Tests by forum members have shown only NFSv4 minor 2 is affected, the other versions, and NFSv3 apparently work correct. And apparently, besides 14.4, 15.0 and 16-current is also affected. On forums popular demand this should become a bug report (sorry, Rick): https://forums.freebsd.org/threads/nfs-read-only-does-not-allow-reading.102080/post-750701 -- You are receiving this mail because: You are the assignee for the bug.home | help
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