Date: Wed, 20 Feb 2019 14:25:35 +0000 From: bugzilla-noreply@freebsd.org To: fs@FreeBSD.org Subject: [Bug 230260] [FUSE] [PERFORMANCE]: Performance issue (I/O block size) Message-ID: <bug-230260-3630-UFFYX3tKAE@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-230260-3630@https.bugs.freebsd.org/bugzilla/> References: <bug-230260-3630@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230260 --- Comment #11 from Kenneth D. Merry <ken@FreeBSD.org> --- Yes, this is inside an LTFS mount. Reading a just-written file does result in only 64K getting read and an unexpected EOF. Here is a dd read of the same file I created in the previous step. The only difference between this and the previous version is that I built the fuse.ko module with change 337165 reverted: {sm4u-12:/root:!:0} cd /mnt {sm4u-12:/mnt:!:0} ls -la total 1048578 drwxrwxrwx 2 root wheel 0 Feb 19 22:20 . drwxr-xr-x 30 root wheel 35 Jan 30 18:45 .. -rwxrwxrwx 1 root wheel 1073741824 Feb 19 22:20 foo {sm4u-12:/mnt:!:0} dd if=foo of=/dev/null bs=1m 1024+0 records in 1024+0 records out 1073741824 bytes transferred in 11.281752 secs (95175096 bytes/sec) So, normal result, no problems. What this tells me is that somehow, changing f_iosize from 4K to DFLTPHYS (which is set to 512K on this particular system) messes up reads (but not writes) for LTFS. In looking at the LTFS FUSE read code, I don't see any hardcoding of the I/O size: https://github.com/LinearTapeFileSystem/ltfs/blob/master/src/ltfs_fuse.c So, perhaps there is a place in the FUSE libraries that is hard-coding the size to 4K? -- You are receiving this mail because: You are the assignee for the bug.
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